The Flat Earth Society

Flat Earth Discussion Boards => Flat Earth Investigations => Topic started by: reer on January 25, 2021, 05:52:14 AM

Title: How does FE explain star trails?
Post by: reer on January 25, 2021, 05:52:14 AM
Often you see long-exposure photos of stars, and how they circle around the celestial poles, such as this one:

(https://earthsky.org/upl/2015/03/star-trails-montauk-point-lighthouse-2016-NY-Neeti-Kumthekar.jpg)

This image is one of many on https://earthsky.org/astronomy-essentials/what-are-star-trails

You can see that many of the stars clearly dip below the horizon. As far as I understand it, this would not be possible on a FE; the stars should dip down, but never go below the horizon. Of course this assumes the horizon is flat, such as the ocean on the right-hand side of this image.

Can one of the FEers explain this to me?
Title: Re: How does FE explain star trails?
Post by: jack44556677 on January 25, 2021, 03:16:54 PM
I highly recommend reading the wiki here first.  Most all of your 101 questions have at least some mention there.

The reason for the star trails is that the stars are in motion, and move in large circles above our heads.

Much like you cannot see the town a few miles down the road, the amount of these circles that you can see from any one place on earth as a human is both limited and finite.

This is the reason you can't see the distant town (assuming it is parallel to you), AND the reason you can't see the entire circle that every star makes.

The horizon is always flat, and is an optical illusion (not the physical edge of something, as we were incorrectly taught).  This fact is regardless of the shape of the earth or conceptions thereof.
Title: Re: How does FE explain star trails?
Post by: SteelyBob on January 25, 2021, 03:48:16 PM

The reason for the star trails is that the stars are in motion, and move in large circles above our heads.


But if they were moving in large circles above our heads, they would appear as ellipses, would they not, due to perspective, unless the observer happened to be directly underneath the centre of rotation? And if, as you suggest, human ability to perceive the stars was a factor, then one would expect the circles to both shrink and get dimmer as the stars got close to the edge of our perception. But that's not what we see, is it? The star trails are quite clearly perfectly circular, each star remains at a constant level of brightness regardless of where it is in its circular journey, and they would be complete circles everywhere if it wasn't for the horizon being in the way - what is happening is quite clearly obscuration by the earth. Human eyesight limitations do not change the path that light takes - whether you're looking at something with human eyes, eagle's eyes, or the world's most powerful telescope, the light will still take the same path - all that changes is the ability of the sensor to sense the smallest amounts of light and resolve small details. The FET arguments around perspective seem very muddled on this subject.

Then if we consider moving location, the only thing that changes is the elevation angle of the two stars at the very centre of the two visible concentric rings, the two respective pole stars, which is why you can only see one of the two from any one latitude on the planet.

This is all entirely consistent with a globe shaped earth whose axis of rotation is aligned with the two respective pole stars.
Title: Re: How does FE explain star trails?
Post by: Action80 on January 25, 2021, 04:31:30 PM
The set of all distant points from the x-axis in 3 dimensional space can be likened to the set of all distant points from the x-axis in 2 dimensional space. If rotated about the x-axis it forms a tube.
Title: Re: How does FE explain star trails?
Post by: jack44556677 on January 25, 2021, 06:24:17 PM
@SteelyBob

Quote
But if they were moving in large circles above our heads, they would appear as ellipses, would they not, due to perspective, unless the observer happened to be directly underneath the centre of rotation?And if, as you suggest, human ability to perceive the stars was a factor, then one would expect the circles to both shrink and get dimmer as the stars got close to the edge of our perception.

I should have said "circular paths" to cover that possibility.  The honest answer is we don't know much about what we are looking at, or what we are looking at it through (or possibly even ON / a part of a larger structure or aggregation of matter).  When dealing with things so far away (we presume from their apparent lack of parallax), we wouldn't necessarily expect much perspective or brightness warping to occur in any case (largely dependent on how far away or bright they are initially, and how far they actually travel away from the observer during their apparent loops)

Quote
The FET arguments around perspective seem very muddled on this subject.

They are as varied and numerous as the stars we are discussing!  Each person has their own understanding, and many (if not all, to some degree) are muddled.

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which is why you can only see one of the two from any one latitude on the planet.

You ought to know that that isn't strictly true, but in any case the reason you can only see certain stars is due to the finite limits/bounds of your sight.  It depends on where you are if you can see the eifel tower or not, for the exact same reason.  You can be standing with a clear line of sight to the eifel tower (or any distant object, yes - including stars) and not be able to see it on a perfectly clear day, just as a result of your distance away from it.

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This is all entirely consistent with a globe shaped earth whose axis of rotation is aligned with the two respective pole stars.

Perhaps that is one of the reasons people have had it wrong for so very long.  They believed the earth was round, and then when they went to look for supporting evidence of that belief, they found things - like the apparent rotation of the lights in the sky - that seemed to support it.  When you see something is moving, it doesn't necessarily mean you are!  As it turns out, there are ways to test wether you are moving or not.

@action80

And those same distant points around an observer in 3 dimensions would form a sphere.  What's your point?
Title: Re: How does FE explain star trails?
Post by: JSS on January 25, 2021, 07:09:52 PM
Quote
which is why you can only see one of the two from any one latitude on the planet.

You ought to know that that isn't strictly true, but in any case the reason you can only see certain stars is due to the finite limits/bounds of your sight.  It depends on where you are if you can see the eifel tower or not, for the exact same reason.  You can be standing with a clear line of sight to the eifel tower (or any distant object, yes - including stars) and not be able to see it on a perfectly clear day, just as a result of your distance away from it.

That isn't true. You can't attribute the stars variable visibility by location simply to the "finite limits/bounds of your sight".

You can see the North Star from both Vietnam and Venezuela and they are over 15,000km apart.

But travel south and soon you can't see the North Star from Manaus in Brazil, which is less than 2,000km away.

Also, the stars don't just slowly fade from view. There is no point on the Earth where you can watch a star fade into the sky as you move. It sinks below the horizon. If it were just getting too far away then you would see the stars fade in and out. But they don't do that, and in fact you should see the stars directly above bright, and get dimmer the further down you look since they are supposed to be further away. This also does not happen. I've taken enough panoramic shots of the sky to see this for myself.

Title: Re: How does FE explain star trails?
Post by: reer on January 26, 2021, 02:59:31 AM
I must be missing something. If the stars (and sun, moon, etc) were always above the horizon, then their tracks might pass very close or even on the horizon, depending on our position. However, it would be clearly impossible for some of those stars to dip vertically below the horizon. No matter what the wiki says, this is clearly not possible if the stars are above the horizon. None of the talk about circles, ellipses, 3D projections, etc can make those stars go down vertically. However, this is trivial to explain if you assume the earth is a rotating globe.

If this is explained in the wiki, please direct me to it, as I could not find it.
Title: Re: How does FE explain star trails?
Post by: SteelyBob on January 26, 2021, 09:20:41 AM
If this is explained in the wiki, please direct me to it, as I could not find it.

You're not missing anything. The wiki tries to invoke several different ideas, but they all fall apart on closer analysis.

There's a very odd argument about perspective, whereby the shortcomings of human vision are used to bring forward the 'vanishing point', which is discussed in quasi-scientific referential terms as if it's a 'thing' in anything other than art class, from infinity to some finite point in front of the viewer.  This is used to explain why the stars get lower in the sky, but it completely fails to explain why they retain their relative angular separation regardless of their position in the sky.

There's also the even odder idea of 'EA', which is allegedly an as-yet undetected process or force by which light is bent upwards over long distances. This is also used to explain why the sun, moon and stars get low in the sky, and disappear below the horizon, despite allegedly being above us, although again, it completely fails to actually explain what we observe - completely undistorted (barring refraction effects close to the horizon) circular star trails, half the sun/moon visible above the horizon at rise/set times...the perfect relationship between latitude and the elevation angle of the pole stars, the fact that all the other stars appear to rotate around the pole stars...the fact that the southern pole star is visible, due south, wherever you are in the southern hemisphere. None of it is explained in any credible way.
Title: Re: How does FE explain star trails?
Post by: jack44556677 on January 26, 2021, 10:10:39 AM
@reer

The wiki isn't flawless, but it does a great job of providing an overview/sense of the disparate and often conflicting views there are out there.

That said, yes - you did miss it : https://wiki.tfes.org/Sunrise_and_Sunset

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However, it would be clearly impossible for some of those stars to dip vertically below the horizon.

Only when you misunderstand optics.  Things that become more and more distant from you appear to converge into the horizon (and ultimately become a part of it).  There is more going on than just that however.  The other major factor is refraction cased by the density gradient in our air.  These are what is most responsible for diverting the light away from your eyes, and are the cause of the optical illusion of "setting" (stars, the sun/moon, boats, you name it).
Title: Re: How does FE explain star trails?
Post by: SteelyBob on January 26, 2021, 10:23:57 AM
Things that become more and more distant from you appear to converge into the horizon

Things that become more distant also appear to get closer together though, as well, don't they? The angle subtended at your eyes by two points gets less and less and they get further away.

But the stars don't do that, do they? They don't converge. They just stay the same distance apart, and merrily rotate around the pole stars in perfect circles.

Title: Re: How does FE explain star trails?
Post by: JSS on January 26, 2021, 01:13:28 PM
Quote
However, it would be clearly impossible for some of those stars to dip vertically below the horizon.

Only when you misunderstand optics.  Things that become more and more distant from you appear to converge into the horizon (and ultimately become a part of it).  There is more going on than just that however.  The other major factor is refraction cased by the density gradient in our air.  These are what is most responsible for diverting the light away from your eyes, and are the cause of the optical illusion of "setting" (stars, the sun/moon, boats, you name it).

This view is not supported the evidence. There is no amount of refraction that will cause a star that is directly overhead to descend smoothly and without distortion all the way down the sky to the horizon.  This amount of refraction has simply never been observed, and would require a truly massive variation in heat and pressure to occur, which has also never been measured. 

There is also no simulation of this effect that can produce the results we see. No computer program that shows what the Flat Earth sky actually is, and then calculates what we see from it.  If you can not describe your effect with enough detail to make predictions, it's not a theory, it's not even a hypothesis since you can't test it.  It's just a guess.

Another very good piece of evidence against the entire sky being an optical illusion is we have deep space radar which can bounce radio signals off objects like the Moon and Venus, and they are exactly where they appear to be.  We have even launched physical objects to the moon and landed them on it, which would be hard to do if it wasn't right where we see it.
Title: Re: How does FE explain star trails?
Post by: SteelyBob on January 26, 2021, 01:25:02 PM
This view is not supported the evidence. There is no amount of refraction that will cause a star that is directly overhead to descend smoothly and without distortion all the way down the sky to the horizon.  This amount of refraction has simply never been observed, and would require a truly massive variation in heat and pressure to occur, which has also never been measured. 

There is also no simulation of this effect that can produce the results we see. No computer program that shows what the Flat Earth sky actually is, and then calculates what we see from it.  If you can not describe your effect with enough detail to make predictions, it's not a theory, it's not even a hypothesis since you can't test it.  It's just a guess.

Another very good piece of evidence against the entire sky being an optical illusion is we have deep space radar which can bounce radio signals off objects like the Moon and Venus, and they are exactly where they appear to be.  We have even launched physical objects to the moon and landed them on it, which would be hard to do if it wasn't right where we see it.

Spot on. I think it's best we avoid discussion of space travel though. For you and me, that might be compelling evidence, but if you've formed the view that it was all faked, then no amount of video evidence, or witness accounts, or anything, is going to convince you otherwise. But the interesting thing, I think, is that of course even if NASA did fake going to the moon, even if every space agency in the world is faking it, even if every micro satellite firm is engaged in some elaborate hoax, the funding for which is mysteriously ever-present, it doesn't change the shape of the world, which could be either flat or round. If space videos are real, the earth is a globe. If they're fake, the earth is either a globe or flat.

That's why the stars questions, like this one, are so good. They are absolutely the kind of observational, anyone-can-do-it science that FET claims to be based on. And of course, as you rightly say, what we observe makes no sense whatsoever on a flat earth. There is no single FET model that can even approximately predict the positions of the sun, moon and stars as they change with time, or with observer location. Somebody truly engaged in some kind of observational, or or indeed zetetic science, would question why the observation doesn't fit their assumptions or hypothesis, and change their thinking.
Title: Re: How does FE explain star trails?
Post by: JSS on January 26, 2021, 05:50:28 PM
Spot on. I think it's best we avoid discussion of space travel though. For you and me, that might be compelling evidence, but if you've formed the view that it was all faked, then no amount of video evidence, or witness accounts, or anything, is going to convince you otherwise.

I can't agree on this point. If we were to avoid every subject that a Flat Earther disagrees with or thinks is part of 'the conspiracy' then we have to throw out everything. Eventually we have nothing at all to discuss because all evidence is contested.

This thread is a good example, the entire field of astronomy is dismissed with the claim that we don't really know what we are looking at, or through, or on when in fact we do know quite a bit about all of these. Those being stars, the atmosphere and the Earth.
Title: Re: How does FE explain star trails?
Post by: SteelyBob on January 26, 2021, 06:03:43 PM
My point is that the only way you will ever persuade a flat earther that the moon landings weren't faked, or that all the ISS footage etc is real, is by physically strapping them into a rocket and sending them into space. Nothing else will do - it's all part of the conspiracy. But the equally important point is that it's irrelevant - even if they were correct, it still proves nothing about the shape of the earth.

The stars, however, and all the good points you've made here are a different game, because if any of the FET assumptions or ideas are shown to be false, then it can't be flat. For obvious reasons, points that are irrelevant or nebulous, like whether coriolis affect water in sinks, or whether a particular ISS video is fake, tend to get a lot of replies - it's the comfort zone of confusion. Precise, direct questions usually get ignored in the noise, so I prefer to keep it on the point, so to speak, and avoid adding to the noise.

Just my thoughts - apologies if that comes across wrong. You're making some great points - thanks.
Title: Re: How does FE explain star trails?
Post by: Jay Seneca on January 26, 2021, 06:19:40 PM
Often you see long-exposure photos of stars, and how they circle around the celestial poles, such as this one:

(https://earthsky.org/upl/2015/03/star-trails-montauk-point-lighthouse-2016-NY-Neeti-Kumthekar.jpg)

This image is one of many on https://earthsky.org/astronomy-essentials/what-are-star-trails

You can see that many of the stars clearly dip below the horizon. As far as I understand it, this would not be possible on a FE; the stars should dip down, but never go below the horizon. Of course this assumes the horizon is flat, such as the ocean on the right-hand side of this image.

Can one of the FEers explain this to me?

Not sure where this video was taken but you can see Ursa Major any time of the year and time of the night in all of the US. I live in southeast US around 30 latitude and I know this to be true. This shouldn’t be possible on RE.
Title: Re: How does FE explain star trails?
Post by: Iceman on January 26, 2021, 06:37:01 PM
This shouldn’t be possible on RE.

What is the basis for that opinion?
Title: Re: How does FE explain star trails?
Post by: Iknowthetruth69 on January 26, 2021, 06:58:44 PM
Well it’s because we have big brain and my mommy told me that it’s true and wold mommy evr lie
Title: Re: How does FE explain star trails?
Post by: SteelyBob on January 26, 2021, 07:16:01 PM
Not sure where this video was taken but you can see Ursa Major any time of the year and time of the night in all of the US. I live in southeast US around 30 latitude and I know this to be true. This shouldn’t be possible on RE.

You're right, it shouldn't be possible to see all of Ursa Major any time of the year and all night in all of the US. The 'big dipper', or the bit of Ursa Major that most people recognise, is visible from most of the states all year round, but only Dubhe, with a declination of 61, would be visible from 30 north all the time (because 30 + 61 > 90). The lowest star in the big dipper, alkaid, is at 49 degrees declination, meaning you'd need to be north of 41 degrees latitude for it to be circumpolar. At 30 north I'd expect most of Ursa Major to be below the horizon, especially in the winter.

If you're experiencing something different to that you are either a) looking for the wrong stars or b) in possession of one of the most earth-shattering observations made by a modern amateur astronomer, and you should definitely tell more people about it, because you could make some serious money out of it. You would be disproving every star almanac, every internet star calculator app...everything. You should start with a video, showing today's paper, some recognisable part of where you live so we can verify the location and then a picture of the whole of Ursa Major.

https://earthsky.org/tonight/where-is-the-big-dipper-on-these-octber-evenings (https://earthsky.org/tonight/where-is-the-big-dipper-on-these-octber-evenings)

I look forward to seeing it.
Title: Re: How does FE explain star trails?
Post by: Longtitube on January 26, 2021, 07:34:45 PM
Not sure where this video was taken but you can see Ursa Major any time of the year and time of the night in all of the US. I live in southeast US around 30 latitude and I know this to be true. This shouldn’t be possible on RE.

First of all, by Ursa Major, do you mean all of the constellation or just the Big Dipper? The Dipper, also known as the Plough, although part of Ursa Major, is not the whole constellation.

Second, from a SE USA location like Albany, Ga (picked at random for its 31deg N latitude) most of Ursa Major dips below the horizon for a few hours in each 24, Dubhe skimming the northern horizon. At this time of year it’s mostly above the horizon by 8pm local time and doesn’t dip below the horizon at all before sunrise.

Lastly, from Miami (about 25deg N), Ursa Major disappears entirely below the northern horizon during part of each day.

On what grounds should any of this be impossible??
Title: Re: How does FE explain star trails?
Post by: JSS on January 26, 2021, 07:53:31 PM
My point is that the only way you will ever persuade a flat earther that the moon landings weren't faked, or that all the ISS footage etc is real, is by physically strapping them into a rocket and sending them into space. Nothing else will do - it's all part of the conspiracy. But the equally important point is that it's irrelevant - even if they were correct, it still proves nothing about the shape of the earth.

The stars, however, and all the good points you've made here are a different game, because if any of the FET assumptions or ideas are shown to be false, then it can't be flat. For obvious reasons, points that are irrelevant or nebulous, like whether coriolis affect water in sinks, or whether a particular ISS video is fake, tend to get a lot of replies - it's the comfort zone of confusion. Precise, direct questions usually get ignored in the noise, so I prefer to keep it on the point, so to speak, and avoid adding to the noise.

Just my thoughts - apologies if that comes across wrong. You're making some great points - thanks.

Oh, it didn't come across wrong at all, just expressing my thoughts. It's always possible to disagree politely. :)

The problem with your approach is that to an FE, nothing can be proven.  Take them up in a rocket, and they can say the windows are just CGI.  I've had this used on me before.  The stars?  Just projections on the dome, another reason I've been told. Holograms.  Or as we saw here recently, maybe the whole universe is a simulation, therefore the Earth is Flat. Try and argue around THAT one.

There is literally nothing you can say that can't be dismissed, so trying to seperate arguments into stuff they can believe and stuff they can't is kind of a fools errand. There is never going to be any evidence that will be acceptable. They have already rejected more evidence than you will ever be able to present, even if you type all day.

Still, it's an interesting challenge, and makes one think, and it';s always good to challenge your own assumptions.  And admit it... you kinda WANT them to present something you can't refute, because that would be FASCINATING.  One can always hope.

Star trails are good because they are so well studied and so well explained that you have a large body of evidence and reasoning to draw upon. I have used all kinds of telescopes and cameras and equipment, and it's the most fun when I can use them to take my own evidence.  I'd made star trail pictures, I've even posted some.  I can explain them by the spinning of a round Earth and far away stars. I have yet to look for a star where it's supposed to be and not see it.
Title: Re: How does FE explain star trails?
Post by: SteelyBob on January 26, 2021, 08:04:18 PM
Good point, and well made.
Title: Re: How does FE explain star trails?
Post by: reer on January 27, 2021, 11:24:30 PM
All the talk about the Big Dipper, and which stars are visible, and when, may be interesting, but it leads us well away from my question, which is:

How does FE explain star trails that seem to dip almost vertically down to the horizon, instead of approaching it gradually, as they should in FET.

Here's another example:
(https://earthsky.org/upl/2013/04/star-trail-over-baja-california.jpg)

Will those stars suddenly make an almost 90 degree turn as they approach the horizon?
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on January 27, 2021, 11:29:15 PM
Light is curing upwards in the FE model - https://wiki.tfes.org/Electromagnetic_Acceleration

Here is a rough star trail simulation of light curving upwards:

https://youtu.be/RkDqdoINhYI?t=372
Title: Re: How does FE explain star trails?
Post by: Iceman on January 27, 2021, 11:52:07 PM
In that video, the demonstration of modelled moon and star paths between about 7:24 and 7:40 show some curious rapid changes in angular separation of the moon and stars in the centre of the frame
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on January 28, 2021, 01:28:58 AM
There is undeniably some warping that doesn't happen in that simulation.

However, I don't think it's true that the stars and celestial bodies always maintain a constant angular diameter from each other in the sky. They slow down as they approach the horizon.

From the below video: "As you can see the stars get significantly closer together as they get closer to the horizon"

https://www.youtube.com/watch?v=m-xXhrTG3Sk

This is opposite from the star trail simulation, but there might be some wiggle room with the particular curve and angle and direction of light as it reaches the observer on the surface that causes it to slow down rather than to speed up. TBD.
Title: Re: How does FE explain star trails?
Post by: SteelyBob on January 28, 2021, 07:33:15 AM
Light is curing upwards in the FE model - https://wiki.tfes.org/Electromagnetic_Acceleration

Here is a rough star trail simulation of light curving upwards:

https://youtu.be/RkDqdoINhYI?t=372

At 6:44

Quote
Let us know if we are doing anything wrong

Well, ok...in the real star videos, as per all of the other ones, and indeed what you will see on any time-lapse footage of the stars, the stars appear to rotate in almost perfect circles - aside from the distortion you get when very close to the horizon from refraction, the stars motion is a circle, regardless of viewer location. In the video you've shown there Tom, the stars are not moving in concentric circles, but rather have some elliptical quality to them. Look at 6:44, and trace pairs of adjacent trails back and forth - they get closer together as they get lower in the sky. That's not what we observe when we look at the stars, and that's because the stars are many hundreds or thousands of light years away, meaning their distance from us is essentially constant regardless of where we are on earth, or where the earth is in its orbit. 
Title: Re: How does FE explain star trails?
Post by: Jay Seneca on January 28, 2021, 07:42:51 AM
Not sure where this video was taken but you can see Ursa Major any time of the year and time of the night in all of the US. I live in southeast US around 30 latitude and I know this to be true. This shouldn’t be possible on RE.

You're right, it shouldn't be possible to see all of Ursa Major any time of the year and all night in all of the US. The 'big dipper', or the bit of Ursa Major that most people recognise, is visible from most of the states all year round, but only Dubhe, with a declination of 61, would be visible from 30 north all the time (because 30 + 61 > 90). The lowest star in the big dipper, alkaid, is at 49 degrees declination, meaning you'd need to be north of 41 degrees latitude for it to be circumpolar. At 30 north I'd expect most of Ursa Major to be below the horizon, especially in the winter.

If you're experiencing something different to that you are either a) looking for the wrong stars or b) in possession of one of the most earth-shattering observations made by a modern amateur astronomer, and you should definitely tell more people about it, because you could make some serious money out of it. You would be disproving every star almanac, every internet star calculator app...everything. You should start with a video, showing today's paper, some recognisable part of where you live so we can verify the location and then a picture of the whole of Ursa Major.

https://earthsky.org/tonight/where-is-the-big-dipper-on-these-octber-evenings (https://earthsky.org/tonight/where-is-the-big-dipper-on-these-octber-evenings)

I look forward to seeing it.

I could show you some timestamp pictures throughout the night. That’s the easy part. The hard part would be proving my location without showing my location. 
Title: Re: How does FE explain star trails?
Post by: SteelyBob on January 28, 2021, 08:18:21 AM
I could show you some timestamp pictures throughout the night. That’s the easy part. The hard part would be proving my location without showing my location.

Great, let's see the pics then - thanks.
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on January 28, 2021, 08:50:13 AM
Well, ok...in the real star videos, as per all of the other ones, and indeed what you will see on any time-lapse footage of the stars, the stars appear to rotate in almost perfect circles - aside from the distortion you get when very close to the horizon from refraction, the stars motion is a circle, regardless of viewer location. In the video you've shown there Tom, the stars are not moving in concentric circles, but rather have some elliptical quality to them. Look at 6:44, and trace pairs of adjacent trails back and forth - they get closer together as they get lower in the sky. That's not what we observe when we look at the stars, and that's because the stars are many hundreds or thousands of light years away, meaning their distance from us is essentially constant regardless of where we are on earth, or where the earth is in its orbit.

I haven't seen much evidence that the stars move in concentric circles.

From the pic in the OP, using a symmetrical circle tool:

(https://earthsky.org/upl/2015/03/star-trails-montauk-point-lighthouse-2016-NY-Neeti-Kumthekar.jpg)

(https://i.imgur.com/zYlpTs5.jpg)

Another pic:

(http://1.bp.blogspot.com/-23W1N1M3ZzI/VLiFrzJC8FI/AAAAAAAACNA/4NN8zb6jyZo/s1600/_JML2072-2145.light.only-13.jpg)

(https://i.imgur.com/r7EpKXQ.jpg)

Title: Re: How does FE explain star trails?
Post by: Longtitube on January 28, 2021, 09:57:22 AM
I haven't seen much evidence that the stars move in concentric circles.

From the pic in the OP, using a symmetrical circle tool:
(https://i.imgur.com/zYlpTs5.jpg)

Another pic:

(https://i.imgur.com/r7EpKXQ.jpg)

Your “symmetrical circle tool” isn’t drawing circles from the same centre each time, nor is it centered on the rotation centre of the sky in either image.

While we’re discussing photos of the stars, have you made sure these images were made with a perfectly rectilinear lens, one that was distortion-free? It would help your case to know.
Title: Re: How does FE explain star trails?
Post by: JSS on January 28, 2021, 02:05:15 PM
I haven't seen much evidence that the stars move in concentric circles.

For the star trails to be perfect circles the lens can't have any significant distortion and must be perfectly aligned with one of the two pole stars, and that star must be in the center of the sensor.

For a lot of artistic shots this is not the case, and you will see visible distortion. This is not unusual, you see distortion in plenty of photographs. Taking pictures of the sky is no exception.

And as pointed out, you didn't draw your circles centered, so of course they are not going to line up.

This is a picture I took myself, with the camera centered on the North Star and using a lens with very little distortion. It's not perfect, I had it set on the roof of a house and the slow cooling during the night warped the trails slightly but as you can see, they are quite circular. I'd show some of my better ones, but for the same reason Jay gave, I do not want to give up my location here.

I've taken lots of pictures like this and can assure you they do move in circles.

(https://i.imgur.com/gBPqYCS.jpg)
Title: Re: How does FE explain star trails?
Post by: SteelyBob on January 28, 2021, 07:50:55 PM


I haven't seen much evidence that the stars move in concentric circles.

I think you're missing the point. Look at 6:44 in the video, and then look at the photos in your post. The trails at 6:44 very clearly show a perspective effect - they are getting closer together as they get further away from the viewer. That's not what we see when we look at the stars.
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on January 28, 2021, 09:31:37 PM
It wouldn't make concentric circles because the stars slow down significantly as they approach the horizon.

There is undeniably some warping that doesn't happen in that simulation.

However, I don't think it's true that the stars and celestial bodies always maintain a constant angular diameter from each other in the sky. They slow down as they approach the horizon.

From the below video: "As you can see the stars get significantly closer together as they get closer to the horizon"

https://www.youtube.com/watch?v=m-xXhrTG3Sk

This is opposite from the star trail simulation, but there might be some wiggle room with the particular curve and angle and direction of light as it reaches the observer on the surface that causes it to slow down rather than to speed up. TBD.

Quote
And as pointed out, you didn't draw your circles centered, so of course they are not going to line up.

(https://i.imgur.com/gBPqYCS.jpg)

The star trails are too short in your example. And the point is to continue the curve, not center the circle.

Quote
Your “symmetrical circle tool” isn’t drawing circles from the same centre each time, nor is it centered on the rotation centre of the sky in either image.

While we’re discussing photos of the stars, have you made sure these images were made with a perfectly rectilinear lens, one that was distortion-free? It would help your case to know.

Equally, you couldn't prove that if you did find an image of circular star trails that it wasn't edited to fix distortion.
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on January 28, 2021, 10:38:53 PM
Here is an example to try, with some nice straight lines in the foreground.

https://www.reddit.com/r/BeAmazed/comments/50ziy3/long_exposure_of_star_trails_against_a_farmhouse/

(https://i.imgur.com/qFV8kKY.jpg)

Hold shift with the circle tool in paint.net for a symmetrical circle. The curves just aren't arcs of a circle, and nor are they concentric:

(https://i.imgur.com/WLdnqxm.jpg)
Title: Re: How does FE explain star trails?
Post by: JSS on January 28, 2021, 11:03:45 PM
Quote
And as pointed out, you didn't draw your circles centered, so of course they are not going to line up.

(https://i.imgur.com/gBPqYCS.jpg)

The star trails are too short in your example. The point is to continue the curve, not center the circle.

My star trails are long enough to show they are circular and not veering off course or heavily distorted.  I'd take a better one tonight if I didn't have clouds.

If you don't center the circle at the point of rotation then of course the circles you draw are not going match. That's how circles work, if you move your circle off-center then of course your circle won't line up. It's impossible for two circles with different origins to line up.

The bigger problem is you can use any computer star-chart program to generate these circles, and see they are indeed circles. And you know those star tracking programs are right because you can take a telescope and point it where the chart says the star is and it's right there, every time.  You can even take pictures and line them up with screenshots.  If the stars were NOT going in concentric circles then nobody would be able to find them with a telescope.

Using random images from the internet without understanding what lens and camera were used is not going to give you reliable results.
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on January 28, 2021, 11:14:47 PM
There is a straight line reference in my previous image. Prove that it's distorted.

The image you provided has zero references to show that it is undistorted and unmodified, and is not following the procedure described.
Title: Re: How does FE explain star trails?
Post by: Iceman on January 28, 2021, 11:16:36 PM
There is a straight line reference in my previous image.

How many images from balloon footage have you discredited despite having the exact same components?
Title: Re: How does FE explain star trails?
Post by: JSS on January 29, 2021, 01:00:54 AM
There is a straight line reference in my previous image. Prove that it's distorted.

The image you provided has zero references to show that it is undistorted and unmodified, and is not following the procedure described.

Prove it's not distorted.

Neither of us can prove anything with that photo because we don't know the details of the camera that took that photo, nor the size and shape of the ground features shown or the exact position of the camera nor do we know what if any image processing was done after the photo was taken. With all those unknowns it's impossible to make any determination at all, which is why I said using random images from the internet is fruitless in trying to prove your case.  That's why I used one of my own, I know all these things.

The procedure as described? What exactly is this procedure and what is it's purpose?

I use a lens specifically designed for no distortion, I'm quite aware of it's capabilities. What 'references' do you require as proof? What could I possibly do to prove to you that the image isn't distorted or modified? Modified how?

You ignored my points about using astronomical star finding software to show that stars do indeed go in perfect circles, backed up by the fact I can use them to find any star in the sky and it's always accurate. Even screenshots can be lined up with actual photos, and I have done this many times to identify stars and features.
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on January 29, 2021, 02:27:04 AM
Quote
Prove it's not distorted.

Neither of us can prove anything with that photo because we don't know the details of the camera that took that photo

Actually, if there is a straight line reference in the photo, it will show whether the lens is producing distortion. Try again.
Title: Re: How does FE explain star trails?
Post by: Longtitube on January 29, 2021, 07:54:56 AM
Tom, you haven’t made a convincing case. The star trail simulation isn’t convincing either; I have never seen the sun or moon rise or set at accelerated rates like in the simulation, nor does either sun or moon elongate as seen rising and setting in the simulation, so that won’t wash. Quoting a video on refraction showing refractive effects within a degree or so of the horizon doesn’t prove your case for the whole sky either.

The OP’s question is still unanswered, why do stars which supposedly circle above earth set?
Title: Re: How does FE explain star trails?
Post by: JSS on January 29, 2021, 01:41:55 PM
Quote
Prove it's not distorted.

Neither of us can prove anything with that photo because we don't know the details of the camera that took that photo

Actually, if there is a straight line reference in the photo, it will show whether the lens is producing distortion. Try again.

This is showing an incorrect understanding of how lenses work.

Here is a picture I just took with a fish eye lens, as you can see it too has a 'straight line reference' which is meaningless for proving other lines are not distorted, as they clearly are.

I'm sorry but random star trail pictures taken with unknown parameters you found on the internet are simply not proof that stars don't move in circles. If that is your only evidence, perhaps you should reconsider your conclusion.

(https://i.imgur.com/ybaYg7Q.png)
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on January 29, 2021, 07:11:08 PM
The straight lines were not centered in the picture in the image of the farm provided. The lines on the elements of the farm were not centered. It appears that you are unable to adequately demonstrate your assertion.

Another rectilinear image. Lines are straight throughout the image:

https://fineartamerica.com/featured/mosquito-creek-star-trails-willard-sharp.html

(https://i.imgur.com/37C0PeN.jpg)

Lines are straight:

(https://i.imgur.com/WUhCj9v.jpg)

Yet it is easy to see that the curves are not concentric circles:

Shift + Circle Tool in Paint.net:

(https://i.imgur.com/hiqQKTr.jpg)
Title: Re: How does FE explain star trails?
Post by: stack on January 29, 2021, 07:59:11 PM
Here's a neat one - Ultra wide-angle lens:

(https://i.imgur.com/qc2hQhH.jpg)

Timelapse of the shoot:

(https://i.imgur.com/SBtJbnZ.gif)

Polish photographer Bartosz Wojczyński pointed his camera straight at the north celestial pole and exposed his camera for a total of six hours...Wojczyński says he was photographing from the Teide Observatory on the Canary Islands, one of the world’s major observatories, from 8PM to 2AM...He captured 620 separate 35-second exposures using his Nikon D5100 and Samyang 10mm lens at ISO 1600 and f/4.8.
https://petapixel.com/2015/04/14/a-six-hour-long-exposure-of-the-celestial-north-pole/
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on January 29, 2021, 08:36:04 PM
I don't see any evidence that that media wasn't edited for artistic reasons to get an ideal result. There aren't many straight line references at all.

Looks like an inability to find satisfactory evidence to me.

In another star trail image that same artist, Bartosz Wojczyński, admits that he's making "curve adjustments" in GIMP:

http://bartoszwojczynski.com/picture-130704-startrails

(https://i.imgur.com/f8qA3TF.png)

The star trails in the image associated with that text certainly wouldn't be circular and concentric if the lens was highly warped like this (warped landmass, trees at odd angles on the sides of image) and there were circular concentric star trails in the sky:

(https://i.imgur.com/zNyLq7U.jpg)
Title: Re: How does FE explain star trails?
Post by: JSS on January 29, 2021, 08:55:36 PM
In another star trail image that same artist, Bartosz Wojczyński, admits that he's making "curve adjustments" in GIMP:

That's color and contrast curves.  Geometric adjustments are called distortion correction.  You can't just do ctrl-f and look for a word without doing a little research to determine what it means in that context.
Title: Re: How does FE explain star trails?
Post by: JSS on January 29, 2021, 09:05:44 PM
The straight lines were not centered in the picture in the image of the farm provided. The lines on the elements of the farm were not centered. It appears that you are unable to adequately demonstrate your assertion.

How was I unable to demonstrate my assertion?

I showed you a picture that I just took showing straight lines and curved lines in the same image.  That proves my assertion that you can't just measure a straight line in one part of a picture and determine the rest is also straight.

You have not proven that your 'straight line measurements' work.  Show me a picture of a grid taken with that camera, with that lens, at the specific zoom as the star trails picture and show that there is no distortion.

You are also claiming photos that show non-circular images have no distortion, while claiming that images that show perfect circles are absolutely distorted. That's conformation bias.
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on January 29, 2021, 09:07:54 PM
In another star trail image that same artist, Bartosz Wojczyński, admits that he's making "curve adjustments" in GIMP:

That's color and contrast curves.  Geometric adjustments are called distortion correction.  You can't just do ctrl-f and look for a word without doing a little research to determine what it means in that context.

Nope. "Curve" could mean any of several different things in Gimp, including the curves in the image.

(https://i.imgur.com/vWa8xZg.png)
Title: Re: How does FE explain star trails?
Post by: stack on January 29, 2021, 09:10:23 PM
I don't see any evidence that that media wasn't edited for artistic reasons to get an ideal result. There aren't many straight line references at all.

Looks like an inability to find satisfactory evidence to me.

In another star trail image that same artist, Bartosz Wojczyński, admits that he's making "curve adjustments" in GIMP:

http://bartoszwojczynski.com/picture-130704-startrails

(https://i.imgur.com/f8qA3TF.png)

Ok, now I 100% know you're being wildly disingenuous and playing dumb regarding "curves" adjustments. You know exactly what "curves" does in GIMP, photoshop, and elsewhere. You've mentioned it before.

8.11. Curves
The Curves tool is the most sophisticated tool for changing the color, brightness, contrast or transparency of the active layer or a selection. While the Levels tool allows you to work on Shadows and Highlights, the Curves tool allows you to work on any tonal range. It works on RGB images.


So stop playing games like the, "Oh, lookee here, the photographer mentioned "curves" he must be making curves (circles) in post-production..." bullshit. My goodness, how low can you go? Just straight-up lying is a terrible look for you.
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on January 29, 2021, 09:12:07 PM
Wrong. The only person being disingenuous here is you. Modifying or adjusting curves could also refer with the curves in the image. - https://docs.gimp.org/2.10/en/plug-in-curve-bend.html

I also noticed that you blatantly ignored the other query. How did this warped picture from that author produce circular concentric star trails?

(https://i.imgur.com/zNyLq7U.jpg)
Title: Re: How does FE explain star trails?
Post by: JSS on January 29, 2021, 09:23:22 PM
In another star trail image that same artist, Bartosz Wojczyński, admits that he's making "curve adjustments" in GIMP:

That's color and contrast curves.  Geometric adjustments are called distortion correction.  You can't just do ctrl-f and look for a word without doing a little research to determine what it means in that context.

Nope. "Curve" could mean any of several different things in Gimp, including the curves in the image.

So are you claiming that you know 100% that he is 'admitting' to adjusting the geometry of the picture in GIMP when he says 'curves adjustment'?  And not adjusting the color curves?

Even though distortion correction has a completely different name?  I doubt a professional photographer is going to mix up those terms.
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on January 29, 2021, 09:27:56 PM
In another star trail image that same artist, Bartosz Wojczyński, admits that he's making "curve adjustments" in GIMP:

That's color and contrast curves.  Geometric adjustments are called distortion correction.  You can't just do ctrl-f and look for a word without doing a little research to determine what it means in that context.

Nope. "Curve" could mean any of several different things in Gimp, including the curves in the image.

So are you claiming that you know 100% that he is 'admitting' to adjusting the geometry of the picture in GIMP when he says 'curves adjustment'?  And not adjusting the color curves?

Even though distortion correction has a completely different name?  I doubt a professional photographer is going to mix up those terms.

It could be either.

It literally says that you are modifying the curves in the tool.

(https://i.imgur.com/WFf2uhw.png)

Once again, how did this very warped picture from that author produce circular concentric star trails?

(https://i.imgur.com/zNyLq7U.jpg)
Title: Re: How does FE explain star trails?
Post by: JSS on January 29, 2021, 09:37:54 PM
It could be either.

It literally says that you are modifying the curves in the tool.

(https://i.imgur.com/WFf2uhw.png)

But once again, how did this warped picture from that author produce circular concentric star trails?

(https://i.imgur.com/zNyLq7U.jpg)

I'm not going to claim I know what you are thinking Tom, but 99% of anyone who knows how images are processed would understand him to be talking about color curves. If he was talking about lens distortion he would have said lens distortion.

As for how he got circular star trails on a warped picture, it is very simple to explain.

Lenses produce circular distortions and they are centered.

If he took a picture of concentric circles that were not centered, they would be distorted.

If he took pictures of concentric squares, they would be distorted.

If he took pictures of concentric triangles, they would be distorted.

See how the ground curves?  And the tree curves?  That's because those are not circles.
Title: Re: How does FE explain star trails?
Post by: stack on January 29, 2021, 09:52:35 PM
Wrong. The only person being disingenuous here is you. Modifying or adjusting curves could also refer with the curves in the image. - https://docs.gimp.org/2.10/en/plug-in-curve-bend.html

I also noticed that you blatantly ignored the other query. How did this warped picture from that author produce circular concentric star trails?

(https://i.imgur.com/zNyLq7U.jpg)

You know you're being beyond disingenuous becasue I know you know what "curves" means in GIMP, photoshop, etc. As well, why didn't you post the technical specs for the photo I posted, which is right here:

Technical information
Location: Observatorio del Teide, Tenerife, Canary Islands
Date and time: 2015 March 14-15, 20:20 WET - 02:20 WET
Camera: Nikon D5100
Mount: Baader Astro & Nature tripod
Optics: Samyang AE 10 mm
Exposure: 620 x 34 sec., ISO 1600, f/4.8
Processing: Adobe Lightroom (NEF development); ProStack (stacking); Adobe Photoshop (curve adjustment)
http://bartoszwojczynski.com/picture-150315-startrails

See that in bold, Adobe Photoshop (curve adjustment). And I know you know what that refers to:
(https://helpx.adobe.com/content/dam/help/en/photoshop/using/curves-adjustment/_jcr_content/main-pars/image_1/curves.png)

In short: You take specs from another photo and use it so it seems more ambiguous rather than using the specs from the actual photo where Photoshop "curve adjustment" means one thing only. And you know exactly what it means. Stop playing games.
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on January 29, 2021, 10:09:57 PM
I'm not going to claim I know what you are thinking Tom, but 99% of anyone who knows how images are processed would understand him to be talking about color curves. If he was talking about lens distortion he would have said lens distortion.

As for how he got circular star trails on a warped picture, it is very simple to explain.

Lenses produce circular distortions and they are centered.

If he took a picture of concentric circles that were not centered, they would be distorted.

If he took pictures of concentric squares, they would be distorted.

If he took pictures of concentric triangles, they would be distorted.

See how the ground curves?  And the tree curves?  That's because those are not circles.

So you believe it was taken with a fisheye lens and that he centered it dead on the center of rotation, as not to produce distortion. It's not centered, but lets pretend that it's a cropped photo and that it was centered.

This invalidates the claim of circular concentric star trails.

If you take a picture of an oval with a fisheye lens it becomes more circular.

(https://i.imgur.com/DbpgeNN.png)

Uploaded to the lunapic fisheye tool: https://www3.lunapic.com/editor/?action=fisheye

Now it's more circular:

(https://i.imgur.com/QLeTixF.png)
Title: Re: How does FE explain star trails?
Post by: JSS on January 29, 2021, 10:19:15 PM
I'm not going to claim I know what you are thinking Tom, but 99% of anyone who knows how images are processed would understand him to be talking about color curves. If he was talking about lens distortion he would have said lens distortion.

As for how he got circular star trails on a warped picture, it is very simple to explain.

Lenses produce circular distortions and they are centered.

If he took a picture of concentric circles that were not centered, they would be distorted.

If he took pictures of concentric squares, they would be distorted.

If he took pictures of concentric triangles, they would be distorted.

See how the ground curves?  And the tree curves?  That's because those are not circles.

So you believe it was taken with a fisheye lens and that he centered it dead on the center of rotation, as not to produce distortion. It's not centered, but lets pretend that it's a cropped photo and that it was centered.

This invalidated the claim of observing circular concentric star trails.

If you take a picture of an oval with a fisheye lens it becomes more circular.

Tom. An oval is not a circle.

If you use a circular distortion on an oval it will distort, just like if you try it on a square.  A circular distortion on a circle will not distort the circle.

None of this even matters, because my picture proves you can't tell if an object is distorted or not by looking at lines elsewhere in the image. Every picture you use as proof that star trails are not circular is useless because you can't show what distortion may or may not be in the image as you didn't take the picture and don't know how it was done or what post processing was performed.

Star trails are circular, as all the calculations for predicting their location are circular and my telescope can find any star I want and they never show up somewhere else in the sky. Astronomers across the world would be having all kinds of trouble if the stars didn't behave the way math shows them to. And when I take pictures of star trails with lenses I know are free of distortion, and that I know are centered because I set it up, they also are circles.

You haven't shown any evidence to the contrary.  Unknown pictures you find on the internet are unreliable.
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on January 29, 2021, 10:42:35 PM
Tom. An oval is not a circle.

If you use a circular distortion on an oval it will distort, just like if you try it on a square.  A circular distortion on a circle will not distort the circle.

None of this even matters, because my picture proves you can't tell if an object is distorted or not by looking at lines elsewhere in the image. Every picture you use as proof that star trails are not circular is useless because you can't show what distortion may or may not be in the image as you didn't take the picture and don't know how it was done or what post processing was performed.

Star trails are circular, as all the calculations for predicting their location are circular and my telescope can find any star I want and they never show up somewhere else in the sky. Astronomers across the world would be having all kinds of trouble if the stars didn't behave the way math shows them to. And when I take pictures of star trails with lenses I know are free of distortion, and that I know are centered because I set it up, they also are circles.

You haven't shown any evidence to the contrary.  Unknown pictures you find on the internet are unreliable.

If you admit that a fisheye will make oval shapes more circular, and you think this guy is centering his warped lenses on the center of rotation, then it discredits the observation of circular star trails.

I don't see that there is anything further to discuss if you can't provide further corroborating information showing that the lens did not distort the star trails into circular shapes.

You know you're being beyond disingenuous becasue I know you know what "curves" means in GIMP, photoshop, etc. As well, why didn't you post the technical specs for the photo I posted, which is right here:

Technical information
Location: Observatorio del Teide, Tenerife, Canary Islands
Date and time: 2015 March 14-15, 20:20 WET - 02:20 WET
Camera: Nikon D5100
Mount: Baader Astro & Nature tripod
Optics: Samyang AE 10 mm
Exposure: 620 x 34 sec., ISO 1600, f/4.8
Processing: Adobe Lightroom (NEF development); ProStack (stacking); Adobe Photoshop (curve adjustment)
http://bartoszwojczynski.com/picture-150315-startrails

See that in bold, Adobe Photoshop (curve adjustment). And I know you know what that refers to:
(https://helpx.adobe.com/content/dam/help/en/photoshop/using/curves-adjustment/_jcr_content/main-pars/image_1/curves.png)

In short: You take specs from another photo and use it so it seems more ambiguous rather than using the specs from the actual photo where Photoshop "curve adjustment" means one thing only. And you know exactly what it means. Stop playing games.

Pretty ambiguous. The same terminology of adjusting a curve can be used in Photoshop to mean geometric curves.

(https://i.imgur.com/zQMDLgu.jpg)
Title: Re: How does FE explain star trails?
Post by: stack on January 29, 2021, 10:57:49 PM
Tom. An oval is not a circle.

If you use a circular distortion on an oval it will distort, just like if you try it on a square.  A circular distortion on a circle will not distort the circle.

None of this even matters, because my picture proves you can't tell if an object is distorted or not by looking at lines elsewhere in the image. Every picture you use as proof that star trails are not circular is useless because you can't show what distortion may or may not be in the image as you didn't take the picture and don't know how it was done or what post processing was performed.

Star trails are circular, as all the calculations for predicting their location are circular and my telescope can find any star I want and they never show up somewhere else in the sky. Astronomers across the world would be having all kinds of trouble if the stars didn't behave the way math shows them to. And when I take pictures of star trails with lenses I know are free of distortion, and that I know are centered because I set it up, they also are circles.

You haven't shown any evidence to the contrary.  Unknown pictures you find on the internet are unreliable.

If you admit that a fisheye will make oval shapes more circular, and you think this guy is centering his warped lenses on the center of rotation, then it discredits the observation of circular star trails.

I don't see that there is anything further to discuss if you can't provide further corroborating information showing that the lens did not distort the star trails into circular shapes.

You know you're being beyond disingenuous becasue I know you know what "curves" means in GIMP, photoshop, etc. As well, why didn't you post the technical specs for the photo I posted, which is right here:

Technical information
Location: Observatorio del Teide, Tenerife, Canary Islands
Date and time: 2015 March 14-15, 20:20 WET - 02:20 WET
Camera: Nikon D5100
Mount: Baader Astro & Nature tripod
Optics: Samyang AE 10 mm
Exposure: 620 x 34 sec., ISO 1600, f/4.8
Processing: Adobe Lightroom (NEF development); ProStack (stacking); Adobe Photoshop (curve adjustment)
http://bartoszwojczynski.com/picture-150315-startrails

See that in bold, Adobe Photoshop (curve adjustment). And I know you know what that refers to:
(https://helpx.adobe.com/content/dam/help/en/photoshop/using/curves-adjustment/_jcr_content/main-pars/image_1/curves.png)

In short: You take specs from another photo and use it so it seems more ambiguous rather than using the specs from the actual photo where Photoshop "curve adjustment" means one thing only. And you know exactly what it means. Stop playing games.

Pretty ambiguous. The same terminology of adjusting a curve can be used in Photoshop to mean geometric curves.

(https://i.imgur.com/zQMDLgu.jpg)

Feel free to quadruple down. Everyone knows you know what "curve adjustment" in PS means. But for the record, even here, the same photographer uses "Adobe Photoshop (curve adjustment)" for this image:

(https://i.imgur.com/8JTUV6h.png)
Technical information
Location: Observatorio del Teide, Tenerife, Canary Islands
Date and time: 2015 March 15, 04:19 - 04:22 WET
Camera: Nikon D5300
Mount: Baader Astro & Nature tripod; Vixen Polarie
Optics: Samyang AE 85 mm
Exposure: 33 x 90 sec., ISO 1600, f/4.8
Processing: Adobe Lightroom (NEF development); DeepSkyStacker (alignment, stacking); Adobe Photoshop (curve adjustment)

http://bartoszwojczynski.com/picture-150315-centaurus-crux

Huh, curve adjustment where there are no circles to "curve"? Weird.

Stop playing games.
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on January 29, 2021, 11:09:10 PM
I don't see that you've proven anything about the true circular nature of the images. You've shown that he may be talking about one type of curve over another in a description.

I'm still waiting on the other query. If the photo was taken with a wide angle lens centered on the point of rotation, then it will turn oval shapes into more circular shapes, invalidating the premise.

I'm not going to claim I know what you are thinking Tom, but 99% of anyone who knows how images are processed would understand him to be talking about color curves. If he was talking about lens distortion he would have said lens distortion.

As for how he got circular star trails on a warped picture, it is very simple to explain.

Lenses produce circular distortions and they are centered.

If he took a picture of concentric circles that were not centered, they would be distorted.

If he took pictures of concentric squares, they would be distorted.

If he took pictures of concentric triangles, they would be distorted.

See how the ground curves?  And the tree curves?  That's because those are not circles.

So you believe it was taken with a fisheye lens and that he centered it dead on the center of rotation, as not to produce distortion. It's not centered, but lets pretend that it's a cropped photo and that it was centered.

This invalidates the claim of circular concentric star trails.

If you take a picture of an oval with a fisheye lens it becomes more circular.

(https://i.imgur.com/DbpgeNN.png)

Uploaded to the lunapic fisheye tool: https://www3.lunapic.com/editor/?action=fisheye

Now it's more circular:

(https://i.imgur.com/QLeTixF.png)
Title: Re: How does FE explain star trails?
Post by: JSS on January 29, 2021, 11:53:06 PM
Tom. An oval is not a circle.

If you use a circular distortion on an oval it will distort, just like if you try it on a square.  A circular distortion on a circle will not distort the circle.

None of this even matters, because my picture proves you can't tell if an object is distorted or not by looking at lines elsewhere in the image. Every picture you use as proof that star trails are not circular is useless because you can't show what distortion may or may not be in the image as you didn't take the picture and don't know how it was done or what post processing was performed.

Star trails are circular, as all the calculations for predicting their location are circular and my telescope can find any star I want and they never show up somewhere else in the sky. Astronomers across the world would be having all kinds of trouble if the stars didn't behave the way math shows them to. And when I take pictures of star trails with lenses I know are free of distortion, and that I know are centered because I set it up, they also are circles.

You haven't shown any evidence to the contrary.  Unknown pictures you find on the internet are unreliable.

If you admit that a fisheye will make oval shapes more circular, and you think this guy is centering his warped lenses on the center of rotation, then it discredits the observation of circular star trails.

I don't see that there is anything further to discuss if you can't provide further corroborating information showing that the lens did not distort the star trails into circular shapes.

You have not understood my argument if you think I am saying that.  I am saying a circular distortion on a lens will not distort a circle.  You showed an oval which is not a circle, of course that will distort.

Why do I have to corroborate some random image on the internet I didn't even post?  I'm not trying to use random images to prove anything, I'm saying they are not useful.

I've said multiple times now you can't trust any random image on the internet to prove star trails are circular or oval.  Unless you take it yourself you can't know what was done to the picture either during or after it was taken.

You should find yourself a cheap star-finding telescope and try it out. You can see for yourself how it can find stars without trouble. If stars were moving in ovals instead of circles then it would be unable to find them. I've done this countless times and can assure you it works. Why would I lie about something anyone can verify for yourself? Thousands of people use these scopes every day. If that's too expensive, star finders on your cell phone are cheap, and free. Easy enough to verify that the stars are right where they should be. Moving in circles. Not ovals.

Title: Re: How does FE explain star trails?
Post by: Tom Bishop on January 30, 2021, 08:00:39 PM
Quote
You have not understood my argument if you think I am saying that.  I am saying a circular distortion on a lens will not distort a circle.  You showed an oval which is not a circle, of course that will distort.

You're supposed to be arguing that the star trails are truly circular and not elliptical or oval. You claimed that the images showing non-circular star trails could have been affected by a warped lens. You guys then promoted the work of a photographer artist who you say is centering his warped lens on the center of rotation.

Yet, a wide angle lens will turn an oval shape into a more circular shape.

Oval:

(https://i.imgur.com/ccxZ3jF.png)

Circle, showing that it is not a circle:

(https://i.imgur.com/rzJOYb5.png)

First image with the wide angle lens via Lunapic:

(https://i.imgur.com/CkeIqfz.png)
Title: Re: How does FE explain star trails?
Post by: JSS on January 30, 2021, 09:22:14 PM
Quote
You have not understood my argument if you think I am saying that.  I am saying a circular distortion on a lens will not distort a circle.  You showed an oval which is not a circle, of course that will distort.

You're supposed to be arguing that the star trails are truly circular and not elliptical or oval. You claimed that the images showing non-circular star trails could have been affected by a warped lens. You guys then promoted the work of a photographer artist who you say is centering his warped lens on the center of rotation.

Ok first, I am not 'you guys'.  Please pay attention to who is making what argument.  I didn't post any star pictures in this thread but ones I took myself.

I am saying that you can not use random images off the internet to prove or disprove stars move in circles or ellipses. You don't know how the picture was taken or how it may have been processed.  Your random internet images of elliptical stars are not reliable, and other random images of circular images are not reliable. Because you don't know enough about either.

You asked some questions about how lenses worked and I answered them.

Once more, the pictures I have taken, myself, with known lenses and properly centered show them to be circular.  The math to calculate their positions also uses circular translation, and the stars are always where they are predicted to be. Moving in circular patterns.

Trying to take a partial curve from a picture where you don't understand the lens geometry or what post processing was done and then extrapolating that curve has so much margin for error it's completely useless as proof of anything, especially when as you did, drew your circles off center.

I might as well be claiming buildings curve because I can find pictures showing that they do. Does the following image prove that building curve? Why then would you assume the sky is curved based on random pictures?

(https://i.imgur.com/1sN4Ah8.jpg)
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on January 31, 2021, 01:40:40 AM
Quote
I am saying that you can not use random images off the internet to prove or disprove stars move in circles or ellipses. You don't know how the picture was taken or how it may have been processed.  Your random internet images of elliptical stars are not reliable, and other random images of circular images are not reliable. Because you don't know enough about either.

Incorrect. If there are references in the image, you can see if the lens is warped or not.

But glad to see that you gave up on proving circular star trails.

Quote
You asked some questions about how lenses worked and I answered them.

Once more, the pictures I have taken, myself, with known lenses and properly centered show them to be circular.  The math to calculate their positions also uses circular translation, and the stars are always where they are predicted to be. Moving in circular patterns.

Oh, so we can't trust random images but we have to trust a rando on the internet who posts here trying to prove that the earth is round.  ::)
Title: Re: How does FE explain star trails?
Post by: Iceman on January 31, 2021, 01:43:45 AM
But the picture wasnt the only evidence was it.... all the star tracking software and apps show circular paths
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on January 31, 2021, 01:55:25 AM
But the picture wasnt the only evidence was it.... all the star tracking software and apps show circular paths

Do they? I just see a sentence on the internet.
Title: Re: How does FE explain star trails?
Post by: stack on January 31, 2021, 02:02:45 AM
But glad to see that you gave up on proving circular star trails.

Do you want to argue about how cameras/lens optics work or about actual star observations?

As JSS pointed out here:

If stars were moving in ovals instead of circles then it would be unable to find them. I've done this countless times and can assure you it works. Why would I lie about something anyone can verify for yourself? Thousands of people use these scopes every day. If that's too expensive, star finders on your cell phone are cheap, and free. Easy enough to verify that the stars are right where they should be. Moving in circles. Not ovals.

And as Iceman just referenced, it's not about random cool looking star trail images found on the web, it's about the actual observation of stars. All of the software and almanacs would have the incorrect position for these stars according to your thinking. Observationally and objectively, that is not the case. And that is the point here.

Observationally, you know, zetetically, this is correct:

(https://i.imgur.com/7dKcYbt.gif)

Observationally, you know, zetetically, you are not correct:
Title: Re: How does FE explain star trails?
Post by: JSS on January 31, 2021, 02:04:23 AM
Quote
I am saying that you can not use random images off the internet to prove or disprove stars move in circles or ellipses. You don't know how the picture was taken or how it may have been processed.  Your random internet images of elliptical stars are not reliable, and other random images of circular images are not reliable. Because you don't know enough about either.

Incorrect. If there are references in the image, you can see if the lens is warped or not.

No, you can not.  Did you forget the picture I posted showing the blinds?  There were straight lines there, and very obviously warped ones.  Unless you think my blinds actually look like that.

You can not prove star trails are curved using random images without knowing how they were taken and processed.  Just like my blinds image proved, straight in one part of the image does not mean straight in another. You need to understand how lenses work before you start making claims like that.

But glad to see that you gave up on proving circular star trails.

What part of my post did you misunderstand to get that conclusion? I even posted my own star trails as my own proof. Please read responses more carefully and understand them before replying.

Quote
You asked some questions about how lenses worked and I answered them.

Once more, the pictures I have taken, myself, with known lenses and properly centered show them to be circular.  The math to calculate their positions also uses circular translation, and the stars are always where they are predicted to be. Moving in circular patterns.

Oh, so we can't trust random images but we have to trust a rando on the internet who posts here trying to prove that the earth is round.  ::)

Yes, because I know all the parameters. I haven't been saying we can't trust random images because people are all lying about them, I'm saying you can't trust them because you do not have all the information needed to make that judgment. I do have all that information.

You don't have to trust me.  You are perfectly capable of taking your own star trail pictures if you think everyone is part of The Conspiracy and out to fool you. Like I'd lie about something anyone can verify themselves. Not my problem to deal with your trust issues.

Feel free to try, just make sure to document what lens or telescope you use, the settings and any post-processing you do. Because apparently you can't trust a random internet weirdo.
Title: Re: How does FE explain star trails?
Post by: stack on January 31, 2021, 02:04:32 AM
But the picture wasnt the only evidence was it.... all the star tracking software and apps show circular paths

Do they? I just see a sentence on the internet.

It's a claim. A claim is evidence, right?
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on January 31, 2021, 02:26:27 AM
Quote
I am saying that you can not use random images off the internet to prove or disprove stars move in circles or ellipses. You don't know how the picture was taken or how it may have been processed.  Your random internet images of elliptical stars are not reliable, and other random images of circular images are not reliable. Because you don't know enough about either.

Incorrect. If there are references in the image, you can see if the lens is warped or not.

No, you can not.  Did you forget the picture I posted showing the blinds?  There were straight lines there, and very obviously warped ones.  Unless you think my blinds actually look like that.

Yes, the straight lines of the blinds were warped. That's how we know that the lens was distorted. If there are references in the image, you can see if the lens is warped or not.

There were straight lines in other images posted and they were straight across various parts of the image, and not warped, showing that the lens was not distorted by a similar effect.

Quote
Like I'd lie about something anyone can verify themselves.

You've come here to lie before. You had previously claimed that you were a computer programmer who has programmed gravity simulations and knew that Numerical Solutions accurately simulated gravity. You lied to us - https://wiki.tfes.org/Numerical_Solutions

Now in this thread you're an astrophotographer claiming to have special knowledge.
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on January 31, 2021, 02:31:24 AM
But glad to see that you gave up on proving circular star trails.

Do you want to argue about how cameras/lens optics work or about actual star observations?

As JSS pointed out here:

If stars were moving in ovals instead of circles then it would be unable to find them. I've done this countless times and can assure you it works. Why would I lie about something anyone can verify for yourself? Thousands of people use these scopes every day. If that's too expensive, star finders on your cell phone are cheap, and free. Easy enough to verify that the stars are right where they should be. Moving in circles. Not ovals.

And as Iceman just referenced, it's not about random cool looking star trail images found on the web, it's about the actual observation of stars. All of the software and almanacs would have the incorrect position for these stars according to your thinking. Observationally and objectively, that is not the case. And that is the point here.

Observationally, you know, zetetically, this is correct:

(https://i.imgur.com/7dKcYbt.gif)

Observationally, you know, zetetically, you are not correct:

Both the distances and angles between the stars change throughout the night in stellarium.

(https://i.imgur.com/lMNgngn.jpg)

(https://i.imgur.com/V1ph9zk.jpg)
Title: Re: How does FE explain star trails?
Post by: JSS on January 31, 2021, 02:47:44 AM
Quote
I am saying that you can not use random images off the internet to prove or disprove stars move in circles or ellipses. You don't know how the picture was taken or how it may have been processed.  Your random internet images of elliptical stars are not reliable, and other random images of circular images are not reliable. Because you don't know enough about either.

Incorrect. If there are references in the image, you can see if the lens is warped or not.

No, you can not.  Did you forget the picture I posted showing the blinds?  There were straight lines there, and very obviously warped ones.  Unless you think my blinds actually look like that.

Yes, the straight lines of the blinds were warped. That's how we know that the lens was distorted. If there are references in the image, you can see if the lens is warped or not.

There were straight lines in other images posted and they were straight across the image, and not warped, showing that the lens was not distorted by a similar effect.

My image had lines of the blinds that were NOT warped, there is your 'straight line reference' so how can you say those lines don't count but the lines in your pictures do?

Quote
Like I'd lie about something anyone can verify themselves.

You continuously come here to lie. You had previously claimed that you were a computer programmer who has programmed gravity simulations and knew that Numerical Solutions accurately simulated gravity. You lied to us - https://wiki.tfes.org/Numerical_Solutions

Now in this thread you're an astrophotographer pretending to have special knowledge.

You called me a liar down in AR but do you really want to do that again up here now? Can you prove I am not a programmer? Can you prove I haven't written n-body simulation software? Can you prove I don't take pictures of stars and planets which is what astrophotography is. I post pictures I take all the time, and I am pretty sure that yes, I have special knowledge about how those were taken, because I took them. How can you say with a straight face I'm only pretending to know how I take my own pictures?  ???

Posting a link to a wiki page you wrote is not proof I am lying.

I even offered to write an n-body simulator in any language you wanted to challenge your calling me a liar, but you backed down and abandoned the discussion.

Can we keep this civil and not resort to personal attacks?
Title: Re: How does FE explain star trails?
Post by: JSS on January 31, 2021, 01:42:29 PM
Both the distances and angles between the stars change throughout the night in stellarium.

Incorrect.  You are showing a simulated extreme wide-angle lens with a 185 degree FOV.  This is obvious from the line of trees around the edge of the image you provided. 

The image is heavily distorted and warped, which should be clear to see at first glance, especially as it says in the upper right what the lens FOV is, which you cropped from your screenshots.  Below is the full screenshot with the FOV data included. 

If you want to do this test correctly you need to use a lens with less distortion like this.  In the second image you can see the distance is correct between the two times as the Earth rotates, showing that the software is indeed moving them in a perfect circle. Not an ellipse.

If you want more conformation of what the software is displaying, you can click on the stars in Stellarium and it gives you their exact position, which you can then use to calculate distances and see that they do not change. This is a far better method than taking screenshots of an obviously warped image and trying to measure pixels.

(https://i.imgur.com/2Lw00xO.jpg)

(https://i.imgur.com/g3vFjM7.jpg)
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on January 31, 2021, 06:48:24 PM
Quote
Can you prove I haven't written n-body simulation software?

Your personal claims of special knowledge don't mean much here. If you want to continue to claim that you're a computer programmer and have special knowledge about numerical solutions I can only encourage you to demonstrate it.

Both the distances and angles between the stars change throughout the night in stellarium.

Incorrect.  You are showing a simulated extreme wide-angle lens with a 185 degree FOV.  This is obvious from the line of trees around the edge of the image you provided. 

The image is heavily distorted and warped, which should be clear to see at first glance, especially as it says in the upper right what the lens FOV is, which you cropped from your screenshots.  Below is the full screenshot with the FOV data included. 

Astronomy programs like Stellarium produce a polar projection, and would be identical to where one was laying down and observing the sky with their ~180 degree field of view.

https://www.e-education.psu.edu/eme810/node/534

(https://i.imgur.com/RskYt5l.png)

(https://i.imgur.com/Y2AMxts.png)
Title: Re: How does FE explain star trails?
Post by: stack on January 31, 2021, 07:16:50 PM
Astronomy programs like Stellarium produce a polar projection, and would be identical to where one was laying down and observing the sky with their ~180 degree field of view.

Stellarium let's you select from 8 projections:

3.3 Projection
3.3.1 Perspective
3.3.2 Equal Area
3.3.3 Stereographic
3.3.4 Fish-eye
3.3.5 Hammer-Aitoff
3.3.6 Cylinder
3.3.7 Mercator
3.3.8 Orthographic

From your image, it looks like you selected maybe Orthographic. I believe the default is "Perspective" with a 60° FOV. Why did you pick something other than the default?
Title: Re: How does FE explain star trails?
Post by: JSS on January 31, 2021, 07:21:32 PM
Quote
Can you prove I haven't written n-body simulation software?

Your personal claims of special knowledge don't mean much here. If you want to continue to claim that you're a computer programmer and have special knowledge about numerical solutions I can only encourage you to demonstrate it.

Tom, I offered to demonstrate it a long while back, remember how I offered to write an n-body simulation in any language you wished?  I've also written a computer program and posted it here recently, you should remember that as Pete took great pleasure in making fun of my 5 minutes of crappy effort.

You abandoned that discussion and never took me up on the offer, so you look pretty silly suddenly demanding I do so now. 

When did I claim I have 'special knowledge' of numerical simulations?  By saying I can write them?  They are very simple to do, any first year comp-sci major could write one, and easily wrine an n-body simulatort as well. It's not hard to do at all.

Both the distances and angles between the stars change throughout the night in stellarium.

Incorrect.  You are showing a simulated extreme wide-angle lens with a 185 degree FOV.  This is obvious from the line of trees around the edge of the image you provided. 

The image is heavily distorted and warped, which should be clear to see at first glance, especially as it says in the upper right what the lens FOV is, which you cropped from your screenshots.  Below is the full screenshot with the FOV data included. 

Astronomy programs like Stellarium produce a polar projection, and would be identical to where one was laying down and observing the sky with their ~180 degree field of view.

Did you not understand my post?  I showed you that the FOV in your examples is 185 degrees which is extremely distorted, mine at 16 degrees is not.

You do not seem to understand how projections work, you are tying to measure lines on a polar projection on a flat surface to get distances, and of course that isn't going to work.

You can not just measure lines randomly on polar projections, you get nonsense results as you did.
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on January 31, 2021, 07:36:09 PM
Quote
Did you not understand my post?  I showed you that the FOV in your examples is 185 degrees which is extremely distorted, mine at 16 degrees is not.

Field of View has nothing to do with distortion. Human vision has a FOV of about 190 degrees.

"our eyes sit in the front of our head, allowing us to see about 60 percent of world in front of us with both eyes, at the compromise that we can only see at maximum about 190 degrees around us (Block 1969; Wolfe 2006)" – Human Spatial Navigation, 2018, p.73

Quote
Tom, I offered to demonstrate it a long while back, remember how I offered to write an n-body simulation in any language you wished?  I've also written a computer program and posted it here recently, you should remember that as Pete took great pleasure in making fun of my 5 minutes of crappy effort.

You abandoned that discussion and never took me up on the offer, so you look pretty silly suddenly demanding I do so now.

When did I claim I have 'special knowledge' of numerical simulations?  By saying I can write them?  They are very simple to do, any first year comp-sci major could write one, and easily wrine an n-body simulatort as well. It's not hard to do at all.

Since we have contemporary sources (https://wiki.tfes.org/Numerical_Solutions) saying that you are incorrect about Numerical Simulations, you're incorrect.

If you are going to argue something, you need to demonstrate it, not claim that you have special knowledge and have special credentials.
Title: Re: How does FE explain star trails?
Post by: stack on January 31, 2021, 07:51:46 PM
Quote
Did you not understand my post?  I showed you that the FOV in your examples is 185 degrees which is extremely distorted, mine at 16 degrees is not.

Field of View has nothing to do with distortion. Human vision has a FOV of about 190 degrees.

When combined with an almost fisheye perspective like you applied it sure does have something to do with it. Is this how humans see with the land wrapped around us like a cylinder:

(https://i.imgur.com/lMNgngn.jpg)
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on January 31, 2021, 07:56:16 PM
Quote
When combined with an almost fisheye perspective like you applied it sure does have something to do with it. Is this how humans see with the land wrapped around us like a cylinder

If you lay down in a field or cleared out area and look up at the sky you do see land and land features 360 degrees around your vision.
Title: Re: How does FE explain star trails?
Post by: stack on January 31, 2021, 08:15:59 PM
Quote
When combined with an almost fisheye perspective like you applied it sure does have something to do with it. Is this how humans see with the land wrapped around us like a cylinder

If you lay down in a field or cleared out area and look up at the sky you do see land and land features 360 degrees around your vision.

No you wouldn't.
(https://perception28.files.wordpress.com/2017/02/human.png)
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on January 31, 2021, 08:22:30 PM
Quote
When combined with an almost fisheye perspective like you applied it sure does have something to do with it. Is this how humans see with the land wrapped around us like a cylinder

If you lay down in a field or cleared out area and look up at the sky you do see land and land features 360 degrees around your vision.

No you wouldn't.
(https://perception28.files.wordpress.com/2017/02/human.png)

Actually, you would.

http://www.vision-and-eye-health.com/visual-field.html

(https://i.imgur.com/HHjcpyl.png)
Title: Re: How does FE explain star trails?
Post by: stack on January 31, 2021, 08:27:28 PM
Quote
When combined with an almost fisheye perspective like you applied it sure does have something to do with it. Is this how humans see with the land wrapped around us like a cylinder

If you lay down in a field or cleared out area and look up at the sky you do see land and land features 360 degrees around your vision.

No you wouldn't.
(https://perception28.files.wordpress.com/2017/02/human.png)

(https://i.imgur.com/HHjcpyl.png)

Lie down on the ground. Can you see your feet? Can you see the surface beyond your feet? Can you see the ground surface off the top of your head? Side to side, can you see the ground surface to your left and to your right when looking straight up?
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on January 31, 2021, 08:41:41 PM
Irrelevant. We have a very wide field of view. If you had a bunch of trees and hills and buildings circled around you, you would see them circled around you.
Title: Re: How does FE explain star trails?
Post by: stack on January 31, 2021, 08:47:40 PM
Irrelevant. We have a very wide field of view. If you had a bunch of trees and hills and buildings circled around you, you would see them circled around you.

So you're saying that when you lie down and look up at the sky you see the world like this:

(https://i.imgur.com/2Lw00xO.jpg)

You must have some sort of ultra-human peripheral vision. Like that of a rabbit's:

(https://i.imgur.com/tjFrE3H.png)
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on January 31, 2021, 09:13:20 PM
A wide angle view is the idea, yes. Refer back to the explanation of a polar projection. It simulates the view of laying down and holding a piece of paper in the air to trace paths. Notice that the labels North, South, East, and West are on the sides of the circle like the image you posted.

https://www.e-education.psu.edu/eme810/node/534

(https://i.imgur.com/RskYt5l.png)

(https://i.imgur.com/Y2AMxts.png)
Title: Re: How does FE explain star trails?
Post by: JSS on January 31, 2021, 09:14:32 PM
When did I claim I have 'special knowledge' of numerical simulations?  By saying I can write them?  They are very simple to do, any first year comp-sci major could write one, and easily wrine an n-body simulatort as well. It's not hard to do at all.

Since we have contemporary sources (https://wiki.tfes.org/Numerical_Solutions) saying that you are incorrect about Numerical Simulations, you're incorrect.

If you are going to argue something, you need to demonstrate it, not claim that you have special knowledge and have special credentials.
[/quote]

If you are going to argue something, you need to have more sources than a Wiki page you wrote. Please explain what in that page you are trying to use as an argument.

If posting a wiki link is a valid argument, I present Three-body_problem (https://en.wikipedia.org/wiki/Three-body_problem) as an example of a problem requiring numerical solutions.

I offered to demonstrate my abilities by writing code for you, you declined to take me up on the offer.

Again you are making your claims about 'special knowledge' and 'special credentials'. Knowing how to program isn't a special credential, it's simply a fact I have proven. Anyone who can program can write an n-body simulator.

I've posted actual star trails I took myself. They show circles. Your only argument is random pictures on the internet with unknown distortions.
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on January 31, 2021, 09:25:34 PM
If you are going to argue something, you need to have more sources than a Wiki page you wrote.

Incorrect. Only a small percentage is original content. The vast majority of that content comes from contemporary sources. You have failed to rebut those sources.

Quote from: JSS
I offered to demonstrate my abilities by writing code for you, you declined to take me up on the offer.

This is just more evidence suggesting fibbing in my book. In the Suggestions Thread you're offing to write a N-Body Gravity Simulation in any language, implying that you are proficient in all computer languages.  ::)

I said I programmed n-body simulations before. I offered to prove it by writing one in any language Tom chose, but Tom declined to take me up on that offer.
Title: Re: How does FE explain star trails?
Post by: stack on January 31, 2021, 09:27:58 PM
A wide angle view is the idea, yes. Refer back to the explanation of a polar projection. It simulates the view of laying down and holding a piece of paper in the air to trace paths. Notice that the labels North, South, East, and West are on the sides of the circle like the image you posted.

Irrelevant. You seem to think you have the field of view of a rabbit.

The world does not look like this when lying down and looking up at the sky:

(https://i.imgur.com/2Lw00xO.jpg)
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on January 31, 2021, 09:38:49 PM
Irrelevant. You seem to think you have the field of view of a rabbit.

Nope. A rabbit laying down on its back would have a much greater field of view than necessary to see both East and West at once.

(https://i.imgur.com/R7FvcnU.png)
Title: Re: How does FE explain star trails?
Post by: stack on January 31, 2021, 09:45:51 PM
Irrelevant. You seem to think you have the field of view of a rabbit.

Nope. A rabbit laying down on its back would have a much greater field of view than necessary to see both East and West at once.

(https://i.imgur.com/R7FvcnU.png)

Like I said you say you can see the world like this:

(https://i.imgur.com/2Lw00xO.jpg)

You have optical powers shared by no other humans. Extraordinary.
Title: Re: How does FE explain star trails?
Post by: JSS on January 31, 2021, 09:50:32 PM
If you are going to argue something, you need to have more sources than a Wiki page you wrote.

Incorrect. Only a small percentage is original content. The vast majority of that content comes from contemporary sources. You have failed to rebut those sources.

So you are admitting the link you posted is just full of links to other sources, not even your own argument.

You have still failed to explain what in that page supports your view.

Quote from: JSS
I offered to demonstrate my abilities by writing code for you, you declined to take me up on the offer.

This is just more evidence of someone fibbing in my book. In the Suggestions Thread you're offing to write a N-Body Gravity Simulation in any language, implying that you are proficient in all computer languages.  ::)

I said I programmed n-body simulations before. I offered to prove it by writing one in any language Tom chose, but Tom declined to take me up on that offer.

This is just showing your ignorance about computer languages.  Anyone who has developed in a wide range of computer languages can pick up a new one without much trouble.  You can ask anyone in the industry and they will tell you the same thing. 

I'm not saying I'm proficient in all computer languages, but I could learn enough about one in a day to write something as simple as an n-body simulator which is just looping through some arrays and performing math on them.

You are very quick to call people a liar when you come across something you don't understand.  Your own ignorance of a subject doesn't mean others can't be very well versed in it.  You are not an expert in all things.

That's why I made the offer in the other thread, which you declined to respond to. I was hoping you would pick something interesting, but no big loss. I will find other uses for my time.
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on January 31, 2021, 09:53:48 PM
Like I said you say you can see the world like this:

You have optical powers shared by no other humans. Extraordinary.

That's what the polar projection assumes, yes.

You can see points over 180 degrees around you. If you can't see such a space vertically because your upper brow is in the way all you need to do is rotate your head. Vertical FOV is fairly high as well.

The argument was that a wide field of view must necessarily produces distortion. Since we can see a very high field of view with human vision, this argument about FOV and distortion is incorrect.
Title: Re: How does FE explain star trails?
Post by: stack on January 31, 2021, 10:05:34 PM
Like I said you say you can see the world like this:

You have optical powers shared by no other humans. Extraordinary.

That's what the polar projection assumes, yes.

You can see points over 180 degrees around you. If you can't see such a space vertically because your upper brow is in the way all you need to do is rotate your head. Vertical FOV is fairly high as well.

The argument was that a wide field of view must necessarily produces distortion. Since we can see a very high field of view with human vision, this argument about FOV and distortion is incorrect.

It really is extraordinary. Not only do you have the FOV of a rabbit, but you can see in a Polar Projection format as well.
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on January 31, 2021, 10:11:45 PM
It really is extraordinary. Not only do you have the FOV of a rabbit, but you can see in a Polar Projection format as well.

I didn't claim anything about having the FOV of a rabbit. You appear to be misinterpreting what the Rabbit's FOV is and the amount necessary to see East and West at once.

The argument was that high FOV means distortion. This argument was unable to be defended.
Title: Re: How does FE explain star trails?
Post by: stack on January 31, 2021, 10:50:38 PM
It really is extraordinary. Not only do you have the FOV of a rabbit, but you can see in a Polar Projection format as well.

I didn't claim anything about having the FOV of a rabbit. You appear to be misinterpreting what the Rabbit's FOV is and the amount necessary to see East and West at once.

The argument was that high FOV means distortion. This argument was unable to be defended.

No, you said:

Astronomy programs like Stellarium produce a polar projection, and would be identical to where one was laying down and observing the sky with their ~180 degree field of view.

Claiming that a polar projection with 180° FOV would be identical to laying down and observing the sky, which you claim would be this:

(https://i.imgur.com/2Lw00xO.jpg)

I don't see the world in a Polar Projection with a 180° FOV like above when laying down and observing the sky. But apparently you do (and rabbits as well). Extraordinary.
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on February 02, 2021, 05:10:59 AM
Quote
I don't see the world in a Polar Projection with a 180° FOV like above when laying down and observing the sky. But apparently you do (and rabbits as well). Extraordinary.

Nope. Rabbits have nearly 360 degree FOV. Humans have an FOV of about 190 degrees. You appear to have difficulty understanding the rabbit diagram you saw and with basic concepts like degrees. Please research these subjects before commenting in the future.
Title: Re: How does FE explain star trails?
Post by: SteelyBob on February 02, 2021, 09:52:44 AM
Tom, in all the chat about rabbits and FOVs, I'm still unclear on one thing - are you standing by your statement that stars, in both real life and in Stellarium, do not move in circles around the pole stars? That their angular separation, in both real life and in Stellarium and other tools, does not remain constant?

I have to say, that picture you showed measuring pixel distances is one of the most absurd arguments I've seen on the internet for a long time. The normally straight-line silhouette features on the horizon wrapping around in an obviously distorted circle.. and then taking a linear measurement on the same picture in two different situations...and expecting to be taken seriously? Astonishing.
 
Title: Re: How does FE explain star trails?
Post by: Action80 on February 02, 2021, 02:24:46 PM
@action80

And those same distant points around an observer in 3 dimensions would form a sphere.  What's your point?
My point is the same distant points cannot form ellipses unless they are spiraling away from the observer toward the farthest observable point. Therefore, they would travel in a circular path overhead.
Title: Re: How does FE explain star trails?
Post by: DuncanDoenitz on February 02, 2021, 02:40:39 PM
Like I said you say you can see the world like this:

You have optical powers shared by no other humans. Extraordinary.

That's what the polar projection assumes, yes.

You can see points over 180 degrees around you. If you can't see such a space vertically because your upper brow is in the way all you need to do is rotate your head. Vertical FOV is fairly high as well.

The argument was that a wide field of view must necessarily produces distortion. Since we can see a very high field of view with human vision, this argument about FOV and distortion is incorrect.

Any lens with a vocal length less than infinity produces a distorted image, and the human eye is a false comparison.  From the moment we open our eyes, our heads start writing software to convert the distorted retinal image into something representing reality, and we can't unlearn that anymore than we can un-learn breathing or pooping. 

And although we may have visual perception over something like 180 degrees, our acuity measures less than 10 degrees.  Hold a newspaper at arms length to your side; you can tell that something is there, but you'll need to turn you head a few degrees to identify it as a newspaper, and look directly at it to read the headline.  I


Title: Re: How does FE explain star trails?
Post by: Tom Bishop on February 02, 2021, 05:39:11 PM
Any lens with a focal length less than infinity produces a distorted image

no

https://www.bhphotovideo.com/explora/photography/tips-and-solutions/perspective-distortion-photographic-composition

(https://i.imgur.com/YCitt7l.png)

(https://i.imgur.com/YrkLNwR.png)

Title: Re: How does FE explain star trails?
Post by: JSS on February 02, 2021, 05:46:24 PM
Any lens with a vocal length less than infinity produces a distorted image

No

https://www.bhphotovideo.com/explora/photography/tips-and-solutions/perspective-distortion-photographic-composition

(https://i.imgur.com/4bPGiun.png)

(https://i.imgur.com/YrkLNwR.png)

Tom, why did you stop your underlining of that quote before it ended?  Did you not read the rest of the sentence?

Fact: a rectilinear lens, regardless of its focal length, will not distort objects in the frame, beyond the aforementioned lens distortions.

The 'aforementioned lens distortions' is referring to the quote But, because light rays are being refracted, even with a rectilinear lens, distortion appears when the light passes through the elements of the lens.

You have just once again, provided a source that disproves your own claim.
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on February 02, 2021, 05:58:45 PM
Maybe a little inherent distortion, but since lines on buildings and structures appear straight beyond anything that is easily detectable in quality rectilinear lenses, it's irrelevant.
Title: Re: How does FE explain star trails?
Post by: SteelyBob on February 02, 2021, 06:06:32 PM
Tom, I'd be grateful if you could answer my question from a few posts back, repeated below for convenience.

Tom, in all the chat about rabbits and FOVs, I'm still unclear on one thing - are you standing by your statement that stars, in both real life and in Stellarium, do not move in circles around the pole stars? That their angular separation, in both real life and in Stellarium and other tools, does not remain constant?

I have to say, that picture you showed measuring pixel distances is one of the most absurd arguments I've seen on the internet for a long time. The normally straight-line silhouette features on the horizon wrapping around in an obviously distorted circle.. and then taking a linear measurement on the same picture in two different situations...and expecting to be taken seriously? Astonishing.
Title: Re: How does FE explain star trails?
Post by: JSS on February 02, 2021, 06:08:13 PM
Maybe a little inherent distortion, but since lines on buildings and structures appear straight beyond anything that is easily detectable in quality rectilinear lenses, it's irrelevant.

It's not irrelevant. As I showed with my example of the blinds, you can't just find a straight line in one part of an image and declare the rest of the image is free of distortions.

If you do not know the exact specifications of the lens that took the picture, if you do not know what was done to it in post production, you can not determine what is distorted and what is not.

That is why all your examples pulled off the internet are no good, you simply can't prove they are distortion free. You can claim the stars are distorted and not the image, but you have no evidence to support that claim.
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on February 02, 2021, 06:11:50 PM
Quote
As I showed with my example of the blinds, you can't just find a straight line in one part of an image and declare the rest of the image is free of distortions.

It wasn't just one part of the image. There were lines all throughout the images posted.

The straight lines were not centered in the picture in the image of the farm provided. The lines on the elements of the farm were not centered. It appears that you are unable to adequately demonstrate your assertion.

Another rectilinear image. Lines are straight throughout the image:

https://fineartamerica.com/featured/mosquito-creek-star-trails-willard-sharp.html

(https://i.imgur.com/37C0PeN.jpg)

Lines are straight:

(https://i.imgur.com/WUhCj9v.jpg)

Yet it is easy to see that the curves are not concentric circles:

Shift + Circle Tool in Paint.net:

(https://i.imgur.com/hiqQKTr.jpg)

And nor are the lines on this farmhouse centered on the image.

Here is an example to try, with some nice straight lines in the foreground.

https://www.reddit.com/r/BeAmazed/comments/50ziy3/long_exposure_of_star_trails_against_a_farmhouse/

(https://i.imgur.com/qFV8kKY.jpg)

Hold shift with the circle tool in paint.net for a symmetrical circle. The curves just aren't arcs of a circle, and nor are they concentric:

(https://i.imgur.com/WLdnqxm.jpg)
Title: Re: How does FE explain star trails?
Post by: Iceman on February 02, 2021, 06:33:08 PM
Same photographer, same bridge... straight lines... still see distortion

https://www.google.ca/imgres?imgurl=https%3A%2F%2Fimages.fineartamerica.com%2Fimages%2Fartworkimages%2Fmediumlarge%2F1%2Fmosquito-creek-star-trail-2-willard-sharp.jpg&imgrefurl=https%3A%2F%2Fpixels.com%2Ffeatured%2Fmosquito-creek-star-trail-2-willard-sharp.html&tbnid=WjdDEbaWkt48bM&vet=12ahUKEwiX06Ln6cvuAhVKSawKHfHoApwQMygQegQIARB_..i&docid=_rnCygLUqSiWjM&w=900&h=600&itg=1&q=mosquito%20creek%20%20bridge%20iowa&ved=2ahUKEwiX06Ln6cvuAhVKSawKHfHoApwQMygQegQIARB_
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on February 02, 2021, 06:51:55 PM
Same photographer, same bridge... straight lines... still see distortion

https://www.google.ca/imgres?imgurl=https%3A%2F%2Fimages.fineartamerica.com%2Fimages%2Fartworkimages%2Fmediumlarge%2F1%2Fmosquito-creek-star-trail-2-willard-sharp.jpg&imgrefurl=https%3A%2F%2Fpixels.com%2Ffeatured%2Fmosquito-creek-star-trail-2-willard-sharp.html&tbnid=WjdDEbaWkt48bM&vet=12ahUKEwiX06Ln6cvuAhVKSawKHfHoApwQMygQegQIARB_..i&docid=_rnCygLUqSiWjM&w=900&h=600&itg=1&q=mosquito%20creek%20%20bridge%20iowa&ved=2ahUKEwiX06Ln6cvuAhVKSawKHfHoApwQMygQegQIARB_

The straight lines throughout the image show that it's taken with a rectilinear lens. If the lens was causing distortion, it would appear in the lines.

If there is distortion, it's caused by something else like resizing the image and not keeping a proper ratio, and nothing to do with the inability of a rectilinear lens to capture the shapes of images.

It might also be that there is no radical distortion in such images and that the stars don't always appear to be as circular from one scene to the next, depending on location and time of day.
Title: Re: How does FE explain star trails?
Post by: JSS on February 02, 2021, 06:53:45 PM
Quote
As I showed with my example of the blinds, you can't just find a straight line in one part of an image and declare the rest of the image is free of distortions.

It wasn't just one part of the image. There were lines all throughout the images posted.

Listen carefully to what I am saying.

You can not use a straight line in one part of an unknown image to determine the distortion in another part.

You measured a few lines, none of which even go the entirety of the image, none of which you proved were perfectly straight in reality, and then tried to claim the image is distortion free. This does not work.

You can not measure spot A and prove spot B has the same distortion, or lack of it.  Especially as you have no idea what post-processing may have been done.

Sorry, but none of those images are useful at all as proof.  That's just not how lenses work.


Title: Re: How does FE explain star trails?
Post by: Tom Bishop on February 02, 2021, 06:57:49 PM
Quote
As I showed with my example of the blinds, you can't just find a straight line in one part of an image and declare the rest of the image is free of distortions.

It wasn't just one part of the image. There were lines all throughout the images posted.

Listen carefully to what I am saying.

You can not use a straight line in one part of an unknown image to determine the distortion in another part.

You measured a few lines, none of which even go the entirety of the image, none of which you proved were perfectly straight in reality, and then tried to claim the image is distortion free. This does not work.

You can not measure spot A and prove spot B has the same distortion, or lack of it.  Especially as you have no idea what post-processing may have been done.

Sorry, but none of those images are useful at all as proof.  That's just not how lenses work.

The image of the blinds you posted showed that the lines were straight only through the center of the image. All other places the lines were warped. If the a lens was warped, it should be detectable in lines in the image.

You have not shown by way of example that straight lines can be scattered throughout an image of a fish-eye lens.
Title: Re: How does FE explain star trails?
Post by: Iceman on February 02, 2021, 07:40:09 PM

The straight lines throughout the image show that it's taken with a rectilinear lens. If the lens was causing distortion, it would appear in the lines.

If there is distortion, it's caused by something else like resizing the image and not keeping a proper ratio, and nothing to do with the inability of a rectilinear lens to capture the shapes of images.

It might also be that there is no radical distortion in such images and that the stars don't always appear to be as circular from one scene to the next, depending on location and time of day.

Arent you basically arguing JSS' point here?
I've provided an image where we dont know about the lens or anything that has been done to the photo in post-processing. You've now (rightly) provided a list of potential issues with the image...
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on February 02, 2021, 07:48:40 PM

The straight lines throughout the image show that it's taken with a rectilinear lens. If the lens was causing distortion, it would appear in the lines.

If there is distortion, it's caused by something else like resizing the image and not keeping a proper ratio, and nothing to do with the inability of a rectilinear lens to capture the shapes of images.

It might also be that there is no radical distortion in such images and that the stars don't always appear to be as circular from one scene to the next, depending on location and time of day.

Arent you basically arguing JSS' point here?
I've provided an image where we dont know about the lens or anything that has been done to the photo in post-processing. You've now (rightly) provided a list of potential issues with the image...

We've been mainly talking about lenses here. I haven't said much about possible post-production effects. Stretching the image in photoshop is possible. It's also possible that the stars in star trails which do seem circular were edited to be more circular because that is the ideal result. Showing that we have no good evidence as originally claimed:

I haven't seen much evidence that the stars move in concentric circles.
Title: Re: How does FE explain star trails?
Post by: SteelyBob on February 02, 2021, 08:37:09 PM
Tom, I'd be grateful if you could answer my question from a few posts back, repeated below for convenience.

Tom, in all the chat about rabbits and FOVs, I'm still unclear on one thing - are you standing by your statement that stars, in both real life and in Stellarium, do not move in circles around the pole stars? That their angular separation, in both real life and in Stellarium and other tools, does not remain constant?

I have to say, that picture you showed measuring pixel distances is one of the most absurd arguments I've seen on the internet for a long time. The normally straight-line silhouette features on the horizon wrapping around in an obviously distorted circle.. and then taking a linear measurement on the same picture in two different situations...and expecting to be taken seriously? Astonishing.
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on February 02, 2021, 08:53:28 PM
I've already answered that. I said that I haven't seen much evidence that the stars make perfect concentric circles.
Title: Re: How does FE explain star trails?
Post by: SteelyBob on February 02, 2021, 09:21:33 PM
I've already answered that. I said that I haven't seen much evidence that the stars make perfect concentric circles.

..and you used a picture from Stellarium where you measured the pixels to try to prove your point, saying:

Quote
Both the distances and angles between the stars change throughout the night in stellarium.

Do you now agree that this was a flawed methodology to use, or are you standing by your point that Stellarium shows that the stars don't maintain their angular separation as they rotate?

Title: Re: How does FE explain star trails?
Post by: Tom Bishop on February 02, 2021, 09:26:52 PM
I've already answered that. I said that I haven't seen much evidence that the stars make perfect concentric circles.

..and you used a picture from Stellarium where you measured the pixels to try to prove your point, saying:

Quote
Both the distances and angles between the stars change throughout the night in stellarium.

Do you now agree that this was a flawed methodology to use, or are you standing by your point that Stellarium shows that the stars don't maintain their angular separation as they rotate?

I haven't seen circular star trails in Stellarium, and nor would Stellarium be a real world observation enough to count as compelling evidence for perfectly circular star trails.
Title: Re: How does FE explain star trails?
Post by: SteelyBob on February 02, 2021, 09:29:04 PM
I've already answered that. I said that I haven't seen much evidence that the stars make perfect concentric circles.

..and you used a picture from Stellarium where you measured the pixels to try to prove your point, saying:

Quote
Both the distances and angles between the stars change throughout the night in stellarium.

Do you now agree that this was a flawed methodology to use, or are you standing by your point that Stellarium shows that the stars don't maintain their angular separation as they rotate?

I haven't seen circular star trails in Stellarium, and nor would Stellarium be a real world observation enough to count as compelling evidence for perfectly circular star trails.

Are you standing by your point that Stellarium shows that the stars don't maintain their angular separation as they rotate? It's a really simple question.
Title: Re: How does FE explain star trails?
Post by: JSS on February 02, 2021, 09:29:11 PM
Quote
As I showed with my example of the blinds, you can't just find a straight line in one part of an image and declare the rest of the image is free of distortions.

It wasn't just one part of the image. There were lines all throughout the images posted.

Listen carefully to what I am saying.

You can not use a straight line in one part of an unknown image to determine the distortion in another part.

You measured a few lines, none of which even go the entirety of the image, none of which you proved were perfectly straight in reality, and then tried to claim the image is distortion free. This does not work.

You can not measure spot A and prove spot B has the same distortion, or lack of it.  Especially as you have no idea what post-processing may have been done.

Sorry, but none of those images are useful at all as proof.  That's just not how lenses work.

The image of the blinds you posted showed that the lines were straight only through the center of the image. All other places the lines were warped. If the a lens was warped, it should be detectable in lines in the image.

You have not shown by way of example that straight lines can be scattered throughout an image of a fish-eye lens.

Yes, that's what an extreme fisheye does. But many lenses, in fact most have only minor distortion in the center, and get worse at the edges and especially the corners.

Your 'method' of trying to draw straight lines in a few places doesn't show that the corners aren't warped.

They also don't show large scale warping across the entire image, where small local areas won't have enough to be detectable, lines crossing the entire field will show distortion.

Like the star trails that cover nearly the entire image.
Title: Re: How does FE explain star trails?
Post by: JSS on February 02, 2021, 09:33:05 PM
I haven't seen circular star trails in Stellarium, and nor would Stellarium be a real world observation enough to count as compelling evidence for perfectly circular star trails.

You should learn to correctly operate the software you use to try and prove your points.

As has been stated many times, the circular star trails produced by Stellarium are indeed compelling evidence since you can use that software to predict the position of the stars anywhere in the world, take pictures and compare them with yours. They will match. That's pretty compelling.
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on February 02, 2021, 09:36:31 PM
Quote from: JSS
Yes, that's what an extreme fisheye does. But many lenses, in fact most have only minor distortion in the center, and get worse at the edges and especially the corners.

There were straight lines all across the entire image at various angles. You keep repeating your weak argument.

I haven't seen circular star trails in Stellarium, and nor would Stellarium be a real world observation enough to count as compelling evidence for perfectly circular star trails.

You should learn to correctly operate the software you use to try and prove your points.

As has been stated many times, the circular star trails produced by Stellarium are indeed compelling evidence since you can use that software to predict the position of the stars anywhere in the world, take pictures and compare them with yours. They will match. That's pretty compelling.

I just see multiple claims here. I haven't seen demonstration of these claims. I look forward to you demonstrating each and every one of your claims beyond dispute.
Title: Re: How does FE explain star trails?
Post by: SteelyBob on February 02, 2021, 09:38:19 PM
Are you standing by your point that Stellarium shows that the stars don't maintain their angular separation as they rotate? It's a really simple question.
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on February 02, 2021, 09:39:09 PM
Are you standing by your point that Stellarium shows that the stars don't maintain their angular separation as they rotate? It's a really simple question.

I haven't seen any evidence that they do. If you think so, I look forward to you providing the compelling evidence for your topic of interest.
Title: Re: How does FE explain star trails?
Post by: SteelyBob on February 02, 2021, 09:42:43 PM
Are you standing by your point that Stellarium shows that the stars don't maintain their angular separation as they rotate? It's a really simple question.

I haven't seen any evidence that they do. If you think so, I look forward to you providing the compelling evidence for your topic of interest.

That’s not what you said though, is it?

You said they didn’t, and you offered a laughably pathetic attempt at science to justify your statement.

That’s not the same thing as saying you haven’t seen evidence that they do, is it?

So, again, are you standing by your statement, or are you admitting you were wrong?
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on February 02, 2021, 09:49:02 PM
Are you standing by your point that Stellarium shows that the stars don't maintain their angular separation as they rotate? It's a really simple question.

I haven't seen any evidence that they do. If you think so, I look forward to you providing the compelling evidence for your topic of interest.

That’s not what you said though, is it?

You said they didn’t, and you offered a laughably pathetic attempt at science to justify your statement.

That’s not the same thing as saying you haven’t seen evidence that they do, is it?

So, again, are you standing by your statement, or are you admitting you were wrong?

Nope, I wasn't wrong at all. I looked at Stellarium and couldn't find circular star trails.

I do see that you have neglected to prove that the polar layout would produce distortion, that every layout produces distortion, or find the one which does not prove distortion. So far the evidence you have produced for your circular star trails remains at zero.
Title: Re: How does FE explain star trails?
Post by: SteelyBob on February 02, 2021, 09:49:53 PM

Nope, I wasn't wrong at all. I looked as Stellarium and couldn't find circular star trails.

So you’re standing by taking linear measurements on a picture which has the normally flat line of the horizon wrapped around in a circle? You don’t see a problem with that exercise?
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on February 02, 2021, 10:02:54 PM

Nope, I wasn't wrong at all. I looked as Stellarium and couldn't find circular star trails.

So you’re standing by taking linear measurements on a picture which has the normally flat line of the horizon wrapped around in a circle? You don’t see a problem with that exercise?

No. I just see a misunderstanding of the polar projection, and planispheres. If you were representing the sky on a piece of paper you would do so on a circle.
Title: Re: How does FE explain star trails?
Post by: SteelyBob on February 02, 2021, 10:16:05 PM

Nope, I wasn't wrong at all. I looked as Stellarium and couldn't find circular star trails.

So you’re standing by taking linear measurements on a picture which has the normally flat line of the horizon wrapped around in a circle? You don’t see a problem with that exercise?

No. I just see a misunderstanding of the polar projection, and planispheres. If you were representing the 180 degree view of the sky on a piece of paper you would do so on a circle.

Indeed you might choose to do that. But if you were to attempt to use a ruler to try to infer the angle subtended at the eyes of an observer between any two points, then other than cases involving measurement from the centre of the azimuthal projection, you will get a wrong answer. As you have done in your example.

You don’t need to even understand azimuthal projections to grasp this - it’s pretty obvious if you think about it.

Title: Re: How does FE explain star trails?
Post by: JSS on February 02, 2021, 11:13:51 PM
Quote from: JSS
Yes, that's what an extreme fisheye does. But many lenses, in fact most have only minor distortion in the center, and get worse at the edges and especially the corners.

There were straight lines all across the entire image at various angles. You keep repeating your weak argument.

The only reason I'm repeating myself is you are not listening.  Drawing a handful of short lines on a cropped image doesn't prove anything.

Worse, there is a bigger problem here than your lines. How do you know the photographer didn't adjust the picture after taking it to make the curved lines of the bridge straight?

I know if I was going to make a picture to sell or display, I'd straighten out the bridge as it would look better.  Can you prove the artist didn't do this?  How?

I haven't seen circular star trails in Stellarium, and nor would Stellarium be a real world observation enough to count as compelling evidence for perfectly circular star trails.

You should learn to correctly operate the software you use to try and prove your points.

As has been stated many times, the circular star trails produced by Stellarium are indeed compelling evidence since you can use that software to predict the position of the stars anywhere in the world, take pictures and compare them with yours. They will match. That's pretty compelling.

I just see multiple claims here. I haven't seen demonstration of these claims. I look forward to you demonstrating each and every one of your claims beyond dispute.

Claims that anyone with a camera and free software could easily prove for themselves. Have you tried it?  What were your results?

If I showed you a photograph that I took, and a matching screenshot of Stellarium that matched the stars displayed, would that suffice for a demonstration beyond dispute?
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on February 02, 2021, 11:30:33 PM

Nope, I wasn't wrong at all. I looked as Stellarium and couldn't find circular star trails.

So you’re standing by taking linear measurements on a picture which has the normally flat line of the horizon wrapped around in a circle? You don’t see a problem with that exercise?

No. I just see a misunderstanding of the polar projection, and planispheres. If you were representing the 180 degree view of the sky on a piece of paper you would do so on a circle.

Indeed you might choose to do that. But if you were to attempt to use a ruler to try to infer the angle subtended at the eyes of an observer between any two points, then other than cases involving measurement from the centre of the azimuthal projection, you will get a wrong answer. As you have done in your example.

You don’t need to even understand azimuthal projections to grasp this - it’s pretty obvious if you think about it.

I would need to see more evidence that it is impossible to portray the shapes an observer sees when looking up at the domed concave celestial sky onto a flat circular plane.

Here is an inverse example with a RE globe. If you are looking down at a globe and saw the great lakes in the shape of a circle for argument's sake (drawn orange circle), why don't you think that this circular shape can be maintained in a projection?

https://gisgeography.com/azimuthal-projection-orthographic-stereographic-gnomonic/

(https://i.imgur.com/tbEJBvr.png)

It literally says that this projection simulates what the observer would see from that position over the globe.

If the observer is hovering over the globe (if it was a globe) and sees the shape of a circle in the United States (orange circle) from that position, why shouldn't it also be a circle in the associated flat projection described?
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on February 03, 2021, 12:40:40 AM
The only reason I'm repeating myself is you are not listening.  Drawing a handful of short lines on a cropped image doesn't prove anything.

Worse, there is a bigger problem here than your lines. How do you know the photographer didn't adjust the picture after taking it to make the curved lines of the bridge straight?

You know that there are lines all throughout this image:

(https://i.imgur.com/37C0PeN.jpg)

Oh, but now it's "cropped" and was adjusted in post-processing. What happened to your argument about distorted lenses? You were arguing:

Quote
I am saying that you can not use random images off the internet to prove or disprove stars move in circles or ellipses. You don't know how the picture was taken or how it may have been processed.  Your random internet images of elliptical stars are not reliable, and other random images of circular images are not reliable. Because you don't know enough about either.

Incorrect. If there are references in the image, you can see if the lens is warped or not.

No, you can not.  Did you forget the picture I posted showing the blinds?  There were straight lines there, and very obviously warped ones.  Unless you think my blinds actually look like that.

It appears that you have conceded this argument. I said that if there are references in the image you can see if the lens is warped or not. You couldn't counter this argument.

You could not maintain that argument about distorted lenses so therefore you have to argue something different and imagine other processing effects. Therefore I was correct. You can indeed tell if it's a distorted lens by looking at the lines throughout the image.
Title: Re: How does FE explain star trails?
Post by: JSS on February 03, 2021, 12:52:34 AM
The only reason I'm repeating myself is you are not listening.  Drawing a handful of short lines on a cropped image doesn't prove anything.

Worse, there is a bigger problem here than your lines. How do you know the photographer didn't adjust the picture after taking it to make the curved lines of the bridge straight?

You know that there are lines all throughout this image:

(https://i.imgur.com/37C0PeN.jpg)

Oh, but now it's "cropped" and was adjusted in post-processing. What happened to your argument about distorted lenses?

Yes Tom, you cropped it. Are you denying you cropped the image you posted below? Cropping means selecting a smaller section of a large image. Pay attention.

The argument is we do not know what kind of distortions the lens has and if it was adjusted in post processing.  Unless one of us contacts the photographer, there is no way to know.  That's my point.

(https://i.imgur.com/WUhCj9v.jpg)

You can't maintain that argument about distorted lenses so therefore you have to argue something different. Therefore I was correct, and you can indeed tell if it's a distorted lens by looking at the lines throughout the image.

No, you were not correct. You can not determine the amount of distortion in one part of an image by measuring some lines elsewhere like you did.

I see you ignored my offer to demonstrate my claims, again. If you are going to demand people demonstrate their claims, it's rather rude to constantly ignore them when they offer to do so.
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on February 03, 2021, 01:21:59 AM
Nope. Do the lines over any of the image. They're straight. They're straight because it is a rectilinear lens.

You are shifting from arguing about the distortion caused by lenses and are arguing about post-processing. This is a different argument than the "lenses can cause distortion" argument you have been peddling. I said "If there are references in the image, you can see if the lens is warped or not." You replied with "No, you can not." If you can't maintain your argument you lose.
Title: Re: How does FE explain star trails?
Post by: JSS on February 03, 2021, 02:29:50 AM
Nope. Do the lines over any of the image. They're straight. They're straight because it is a rectilinear lens.

You are shifting from arguing about the distortion caused by lenses and are arguing about post-processing. This is a different argument than the "lenses can cause distortion" argument you have been peddling. I said "If there are references in the image, you can see if the lens is warped or not." You replied with "No, you can not." If you can't maintain your argument you lose.

It's the same argument: Measuring lines tells you nothing about the scene as you lack the information to determine that.

It doesn't matter if it's because the lens is curved, or post processing, optical illusions or any other reason. You have no way to know, therefore it's not proof.

Again I challenge you, how can you prove the lines are straight because that's how the picture was taken, or because it was post processed to straighten them out?

No you can't.  Drawing a few lines in the center of the image doesn't help determine the curve at the edge.  It doesn't tell you what part of the image was straight and now bent, and what was bent and now straight.

You keep claiming it was taken with a rectilinear lens.  Source?  Not that it matters in the least as was proved to you earlier, they also have distortion, which you also seem to have forgotten.

Also, are you ever going to respond to the following?  You made a demand, I responded, and you have ignored it multiple times now.

I just see multiple claims here. I haven't seen demonstration of these claims. I look forward to you demonstrating each and every one of your claims beyond dispute.

Claims that anyone with a camera and free software could easily prove for themselves. Have you tried it?  What were your results?

If I showed you a photograph that I took, and a matching screenshot of Stellarium that matched the stars displayed, would that suffice for a demonstration beyond dispute?

So, would you?  If I provide you with a screenshot and a photo I took that line up, will you accept that Stellarium produces accurate output?

You could also do this yourself, as I said. The only reason you haven't seen any demonstrations is because you don't want to look.  I'm not proposing anything extreme here, just that software widely used to predict the positions of stars does what it says.
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on February 03, 2021, 02:48:25 AM
Nope. Do the lines over any of the image. They're straight. They're straight because it is a rectilinear lens.

You are shifting from arguing about the distortion caused by lenses and are arguing about post-processing. This is a different argument than the "lenses can cause distortion" argument you have been peddling. I said "If there are references in the image, you can see if the lens is warped or not." You replied with "No, you can not." If you can't maintain your argument you lose.

It's the same argument: Measuring lines tells you nothing about the scene as you lack the information to determine that.

It doesn't matter if it's because the lens is curved

Wrong again. Measuring these lines tells you that there is lens distortion in the image.

(https://i.imgur.com/ybaYg7Q.png)

The rest of your post speculating about possible post-processing is irrelevant to this point you keep insisting on, and which you continue to be wrong about. It is possible to tell if there is lens distortion with straight lines in the image.
Title: Re: How does FE explain star trails?
Post by: JamesonM on February 03, 2021, 02:50:23 AM
I read this thread with interest. I’m an amateur astronomer and do some astrophotography. I use stellarium (I saw some other threads wondering about it’s validity). Star trails are a problem we fight in astrophotography regularly because they ruin long exposure images. Anyway, I can take a video of myself setting up and capturing a celestial object if that helps. I’d do it live - so no modification involved. It’s just a refractor and cmos camera, so nothing tricky.
Title: Re: How does FE explain star trails?
Post by: JSS on February 03, 2021, 03:03:03 AM
Nope. Do the lines over any of the image. They're straight. They're straight because it is a rectilinear lens.

You are shifting from arguing about the distortion caused by lenses and are arguing about post-processing. This is a different argument than the "lenses can cause distortion" argument you have been peddling. I said "If there are references in the image, you can see if the lens is warped or not." You replied with "No, you can not." If you can't maintain your argument you lose.

It's the same argument: Measuring lines tells you nothing about the scene as you lack the information to determine that.

It doesn't matter if it's because the lens is curved

Wrong again. Measuring these lines tells you that there is lens distortion in the image.

You took one image, measured straight lines in part of it and claimed the rest of the image is not distorted.

Well, look at the blinds. I can measure several straight lines, can I claim the rest of the image is not distorted?

Prove I don't have curved blinds.

Prove the middle blind isn't actually curbed and I post-processed it to make it straight?

You can't do any of these, just as you can't tell in your star trails picture what the original geometry of the scene was after lens distortion and unknown 'curve corrections' which as you stated earlier, must mean a picture is not showing reality.

(https://i.imgur.com/ybaYg7Q.png)

The rest of your post speculating about possible post-processing is irrelevant to this point you keep insisting on, and which you continue to be wrong about. It is possible to tell if there is lens distortion with straight lines in the image.
[/quote]

It's entirely relevant, as it's my main point.  You can't know what the original scene looked like from a picture with unknown properties and unknown transformations.

I'm speculating there likely have been corrections made. You are speculating that there have not. The POINT is that neither of us can prove it, therefore the photo is useless as proof of what you claim.
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on February 03, 2021, 03:10:38 AM
Prove I don't have curved blinds.

Your arguments just get worse and worse.

Lets just end it here and let anyone reading decide whether it is reasonable that you have curved blinds and that the lines on the structures of a metal bridge are curved in just the right way to look straight to a distorted camera lens.  ::)
Title: Re: How does FE explain star trails?
Post by: JSS on February 03, 2021, 03:14:33 AM
Prove I don't have curved blinds.

Your arguments keep getting worse and worse.

Lets just end it here and let anyone reading decide whether it is more reasonable that you have curved blinds and that the lines on the structures of a bridge are curved in just the right way to look straight to a distorted camera lens.  ::)

You are misrepresenting my point, again.

Everyone knows it's reasonable to assume I don't have curved blinds.

But from that picture, they can't PROVE it.  Something being reasonable isn't proof.  I could have hand-made some curved blinds which is an unreasonable thing to do, but possible. But from that photo nobody can prove it.  Just as you can't prove stars go in ovals just because you found a distorted picture. It doesn't matter if you think it's a reasonable assumption or not, it's not proof.

My arguments are fine, your interpretation and misunderstanding of them is the problem.
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on February 03, 2021, 03:21:28 AM
Prove I don't have curved blinds.

Your arguments keep getting worse and worse.

Lets just end it here and let anyone reading decide whether it is more reasonable that you have curved blinds and that the lines on the structures of a bridge are curved in just the right way to look straight to a distorted camera lens.  ::)

You are misrepresenting my point, again.

Everyone knows it's reasonable to assume I don't have curved blinds.

But from that picture, they can't PROVE it.  Something being reasonable isn't proof.  I could have hand-made some curved blinds which is an unreasonable thing to do, but possible. But from that photo nobody can prove it.  Just as you can't prove stars go in ovals just because you found a distorted picture. It doesn't matter if you think it's a reasonable assumption or not, it's not proof.

My arguments are fine, your interpretation and misunderstanding of them is the problem.

Everyone also knows that it's reasonable that the lines on a metal bridge or similar structure are straight, and not curved in the right amount to look straight to a distorted camera lens.

Your arguments are poor.
Title: Re: How does FE explain star trails?
Post by: JSS on February 03, 2021, 03:31:01 AM
Prove I don't have curved blinds.

Your arguments keep getting worse and worse.

Lets just end it here and let anyone reading decide whether it is more reasonable that you have curved blinds and that the lines on the structures of a bridge are curved in just the right way to look straight to a distorted camera lens.  ::)

You are misrepresenting my point, again.

Everyone knows it's reasonable to assume I don't have curved blinds.

But from that picture, they can't PROVE it.  Something being reasonable isn't proof.  I could have hand-made some curved blinds which is an unreasonable thing to do, but possible. But from that photo nobody can prove it.  Just as you can't prove stars go in ovals just because you found a distorted picture. It doesn't matter if you think it's a reasonable assumption or not, it's not proof.

My arguments are fine, your interpretation and misunderstanding of them is the problem.

Everyone also knows that it's reasonable that the lines on a bridge or similar structure are straight, and not curved in the right amount to look straight to a distorted camera lens.

Your arguments are poor.

Again, it doesn't matter what is reasonable or not.  Everyone knows it's reasonable to think the Earth is round, will you accept that line of reasoningtoo?

To me, it's reasonable that the lines on a bridge using a wide angle lens will look curved, and if they are straight it means some post-processing correction was applied.

Reasonable doesn't matter.  Can I prove it?  No.  Can you prove it?  No.
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on February 03, 2021, 03:42:43 AM
Quote
Again, it doesn't matter what is reasonable or not.

Actually, it does. It's an increasingly desperate argument to resort to that. Your desperate arguments now have you calling for the possibility of curved blinds and metal bridges curved in just the right way so that it seems straight in the right places to a distorted camera lens. You are arguing this so you can justify your argument.

This 'possibility' is just garbage. You are spamming our forum. Kindly stop.
Title: Re: How does FE explain star trails?
Post by: JSS on February 03, 2021, 03:44:18 AM
Ok, here is another picture to illustrate my point that if you don't know the details, you can't prove what the shape of an object in a picture is.

In it is a ruler and a cable. That cable may be straight, it may be curved up, it may be curved down. Maybe both.

A challenge to you, Tom. Based on the ruler which I assure you is straight in reality, tell me which way that cable is curved and by how much and how you have determined this.

If you can't determine if or how the cable curves, how can you determine it the oval curves of those star trails is real?

(https://i.imgur.com/TDnFVpo.jpg)
Title: Re: How does FE explain star trails?
Post by: JSS on February 03, 2021, 03:48:52 AM
Quote
Again, it doesn't matter what is reasonable or not.

Actually, it does. It's an increasingly desperate argument to resort to that. Your desperate arguments now have you calling for the possibility of curved blinds and metal bridges curved in just the right way so that it seems straight in the right places to a distorted camera lens. You are arguing this so you can justify your argument.

This 'possibility' is just garbage. You are spamming our forum. Kindly stop.

Please see my post above.

Also, pay very close attention to what the words 'reasonable' and 'possible' and 'proof' mean.  Saying something is reasonable is not proof.

I am not calling for the possibility of bridges curving, I have stated clearly that the image produced will be curved, and is often corrected.  Distortion correction is almost required with wide angle lenses if you want straight lines.  Find me a 180 degree wide angle that produces completely straight lines with no distortion. It does not exist.

Title: Re: How does FE explain star trails?
Post by: Tom Bishop on February 03, 2021, 04:20:31 AM
Quote
A challenge to you, Tom. Based on the ruler which I assure you is straight in reality, tell me which way that cable is curved and by how much and how you have determined this.

No thanks. Not interested in engaging you any further. I have determined that you are most likely spamming this forum with whatever frivolous argument that you can make, and will justify that dogs are cats and up is down if you think it will help you. Kindly cease.
Title: Re: How does FE explain star trails?
Post by: stack on February 03, 2021, 05:08:38 AM
I have no idea if the distortion in the image is in camera (lens) or was achieved in post, but there's definitely something going on. The bridge, though the i-beams are straight unto themselves, they sure slant in a very distorted way toward the left. See the red arrows as I would expect the beams to be:

(https://i.imgur.com/os0Km1G.jpg)

Here's another one of the guy's photos - Same bridge. See what I mean:

(https://i.imgur.com/MHlGCJn.jpg)

All in all, they aren't really good examples because we don't know the lenses used and/or post-production effects employed. But there's definitely some distortion.

Title: Re: How does FE explain star trails?
Post by: Tom Bishop on February 03, 2021, 07:07:54 AM
See the red arrows as I would expect the beams to be:

(https://i.imgur.com/os0Km1G.jpg)

No. Vertical structures tilt if the camera is crooked and not parallel with the surface.
Title: Re: How does FE explain star trails?
Post by: Longtitube on February 03, 2021, 07:15:05 AM
See the red arrows as I would expect the beams to be:

(https://i.imgur.com/os0Km1G.jpg)

No. Vertical structures tilt if the camera is crooked and not parallel with the surface.

Whereas the star paths are unaffected? You see what you just said? Wow.
Title: Re: How does FE explain star trails?
Post by: JSS on February 03, 2021, 11:44:22 AM
Quote
A challenge to you, Tom. Based on the ruler which I assure you is straight in reality, tell me which way that cable is curved and by how much and how you have determined this.

No thanks. Not interested in engaging you any further. I have determined that you are most likely spamming this forum with whatever frivolous argument that you can make, and will justify that dogs are cats and up is down if you think it will help you. Kindly cease.

My arguments are not frivolous nor spamming just because you say so. What exactly are you asking me to cease doing?

My argument is the same as always, you can't tell the distortion in one section of an image by measuring another if you don't know the exact properties of the lens and whatever post-processing may have been done.  This is very simple, and the picture is to provide an example.

You claim you can tell if stars are distorted or not because you measured something else in the image. If you can do that, why can't you do the same in my image? Refusing to even try simply shows you are unable to do so.
Title: Re: How does FE explain star trails?
Post by: Iceman on February 03, 2021, 01:43:14 PM
(https://i.imgur.com/xZDrtDa.png)

Same bridge, same photographer, same stars. Circles added...to the circular paths...
Title: Re: How does FE explain star trails?
Post by: JSS on February 03, 2021, 02:46:17 PM
(https://i.imgur.com/xZDrtDa.png)

Same bridge, same photographer, same stars. Circles added...to the circular paths...

Good find. I mentioned earlier in the thread that circular trails would not be distorted if centered in the lens. Nice to see an example from the same photographer of the same bridge.

It should be crystal clear now that the oval trails in his other images are indeed distorted by the lens, since the distortions only appear when the origin of the star trail circles is not centered in the frame.
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on February 03, 2021, 03:00:04 PM
The procedure described was to follow a long start trail rather than trying to wing it. However, these trails are a bit too short for that procedure anyway.

The circle overlaps trails in the image:

(https://i.ibb.co/m6QXHTf/xZDrtDa.png)
Title: Re: How does FE explain star trails?
Post by: JSS on February 03, 2021, 03:13:24 PM
The procedure described was to follow a long start trail rather than trying to wing it. However, these trails are a bit too short for that procedure anyway.

What is the minimum length of a star trail to be valid for your procedure?  These trails seem to cover about 12 degrees.  How many degrees is needed?
Title: Re: How does FE explain star trails?
Post by: AATW on February 03, 2021, 05:18:37 PM
I haven't really been following this tread tbh but is Tom arguing that star trails aren't circular? If so then I don't see how that really helps FE and on this Wiki page it says

Quote
The stars in the night sky trace almost perfect circles around the hub of the earth because by necessity the mechanics of a multiple system rely intimately on the movements and vectors of every member body. Circular movement is the most perfect, stable movement. If one celestial body is out of place or moves in a different fashion than the other bodies of the group the entire system becomes inherently imbalanced. Eddies, or stars that move out of tandem, will either leave the system entirely or are compelled by the stellar system to move back into its locked pace and apogee. This is why there are no elliptical orbits.

https://wiki.tfes.org/Star_Rotation

The bigger issue for FE is why the trails go in the opposite direction in the southern hemi-plane. This is to be expected on a sphere, you're "upside down" and thus going the other way around from your frame of reference. Not sure how that would work on a flat earth.
Title: Re: How does FE explain star trails?
Post by: SteelyBob on February 04, 2021, 09:06:59 AM
I haven't really been following this tread tbh but is Tom arguing that star trails aren't circular? If so then I don't see how that really helps FE and on this Wiki page it says

Quote
The stars in the night sky trace almost perfect circles around the hub of the earth because by necessity the mechanics of a multiple system rely intimately on the movements and vectors of every member body. Circular movement is the most perfect, stable movement. If one celestial body is out of place or moves in a different fashion than the other bodies of the group the entire system becomes inherently imbalanced. Eddies, or stars that move out of tandem, will either leave the system entirely or are compelled by the stellar system to move back into its locked pace and apogee. This is why there are no elliptical orbits.

https://wiki.tfes.org/Star_Rotation

The bigger issue for FE is why the trails go in the opposite direction in the southern hemi-plane. This is to be expected on a sphere, you're "upside down" and thus going the other way around from your frame of reference. Not sure how that would work on a flat earth.

Great point!

I'm still waiting for Tom to explain my apparent misunderstanding of polar azimuthal projections and how, contrary to popular belief, you can make straight-line measurements on them and compare any two different parts of the projection without fear of distorted results.
Title: Re: How does FE explain star trails?
Post by: JSS on February 04, 2021, 02:32:55 PM
I finally got a clear night and managed to capture some star trails.  I couldn't get to a really good location for a full sky view that wasn't blocked in some way, that will have to wait for spring.

I made sure that Polaris was centered in the frame so there would be no barrel distortion.

Tom never said how long the star trails need to be for his procedure, but hopefully these are long enough.

As you can see, these are circular.  They are not oval, they are not massively distorted, they do not look anything like the bridge pictures that were shown.

I made no distortion corrections to this image. It's not warped in any way. I did crop it and removed the horizon.

Overall I'm pretty happy with this, it shows what I wanted and is just in general, pretty to look at. I never took star trails perfectly centered before, I always tried to frame the picture to be interesting. So this was fun.

This experiment proves (if only to myself) that star trails are indeed circular. I know the camera, lens, setting and everything done to this image so there can be no doubt in my mind.  If anyone has questions, feel free to ask.

(https://i.imgur.com/XJiUnN4.jpg)
Title: Re: How does FE explain star trails?
Post by: AATW on February 04, 2021, 02:44:53 PM
That is outstanding work. JSS.
I thought of something else this morning. If the stars are rotating above the plane of the flat earth and the rotation is about the centre of the disc then the only point at which they would trace circles in the sky is from the North Pole.
Anywhere else and you're "off centre" which would mean the circle they trace would be flattened from your point of view.
But that isn't what is observed, as you have shown,
Title: Re: How does FE explain star trails?
Post by: SteelyBob on February 04, 2021, 04:44:59 PM
That is outstanding work. JSS.
I thought of something else this morning. If the stars are rotating above the plane of the flat earth and the rotation is about the centre of the disc then the only point at which they would trace circles in the sky is from the North Pole.
Anywhere else and you're "off centre" which would mean the circle they trace would be flattened from your point of view.
But that isn't what is observed, as you have shown,

Indeed - I keep making that point but it's usually ignored. If you go back to the FE modelling video that Tom posted earlier in this thread you'll see precisely that kind of elliptical shape in the star trails, which is kind of how we got onto this rather lengthy discussion around whether or not real star trails are circular.

There remains no credible FE explanation of how that circular rotation pattern is observed everywhere, with the centre point (ie the pole stars) of each changing elevation in response to moving observer latitude. And then of course it gets worse for FET when you throw in the southern celestial pole and the fact that it's always south regardless of where you view it from.
Title: Re: How does FE explain star trails?
Post by: JSS on February 04, 2021, 06:12:17 PM
That is outstanding work. JSS.
I thought of something else this morning. If the stars are rotating above the plane of the flat earth and the rotation is about the centre of the disc then the only point at which they would trace circles in the sky is from the North Pole.
Anywhere else and you're "off centre" which would mean the circle they trace would be flattened from your point of view.
But that isn't what is observed, as you have shown,

Thanks!  That was hours and hours of work, although most of it was waiting.  I eventually got tired and had to go to bed. I've got some equipment on order to help with taking longer ones, now that I've gotten excited about doing it again. I do love this site for inspiring me. Wish the weather would cooperate though.

I am certainly not living at the north pole, far from it, so if the star paths were distorted away from it I would certainly see evidence of it here. 

In my opinion I think that photo is pretty definitive when it comes to answering the question here if stars go in circles or ellipses, unless someone can point out any major flaws in my technique. I think I covered everything though.

Back to the question at hand?  How does FE explain circular star trails?
Title: Re: How does FE explain star trails?
Post by: Longtitube on February 04, 2021, 07:43:52 PM
I finally got a clear night and managed to capture some star trails.  I couldn't get to a really good location for a full sky view that wasn't blocked in some way, that will have to wait for spring.

I made sure that Polaris was centered in the frame so there would be no barrel distortion.

Tom never said how long the star trails need to be for his procedure, but hopefully these are long enough.

As you can see, these are circular.  They are not oval, they are not massively distorted, they do not look anything like the bridge pictures that were shown.

I made no distortion corrections to this image. It's not warped in any way. I did crop it and removed the horizon.

Overall I'm pretty happy with this, it shows what I wanted and is just in general, pretty to look at. I never took star trails perfectly centered before, I always tried to frame the picture to be interesting. So this was fun.

This experiment proves (if only to myself) that star trails are indeed circular. I know the camera, lens, setting and everything done to this image so there can be no doubt in my mind.  If anyone has questions, feel free to ask.

(https://i.imgur.com/XJiUnN4.jpg)

Yep, nice job. ;D  I make the angle of rotation around 63 degrees, so using Bob Knodel's handy aide-memoire that makes an exposure of around 4 hrs 12 minutes?  That image would illustrate the wiki article quite nicely.
Title: Re: How does FE explain star trails?
Post by: JSS on February 04, 2021, 08:32:48 PM
(https://i.imgur.com/XJiUnN4.jpg)

Yep, nice job. ;D  I make the angle of rotation around 63 degrees, so using Bob Knodel's handy aide-memoire that makes an exposure of around 4 hrs 12 minutes?  That image would illustrate the wiki article quite nicely.

Nice job on the math.  I just checked the timestamps and you are dead on.  Exactly 4 hours 12 minutes between the first and last pictures used in this image.

I ended up giving up and going to bed eventually.  I'm too old to be able to go all night anymore. :)

I had to keep switching batteries every hour or so, which also ran the risk of bumping the camera. I've got a DC power supply on order for the next clear night which by my calculations will be in about 3 months. Sigh.
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on February 04, 2021, 08:37:11 PM
Quote from: JSS
I finally got a clear night and managed to capture some star trails.

Your evidence isn't good around here. A moderator of this forum has branded you to be a compulsive liar, and you have blatantly lied in previous threads.
Title: Re: How does FE explain star trails?
Post by: SteelyBob on February 04, 2021, 08:56:30 PM
Quote from: JSS
I finally got a clear night and managed to capture some star trails.

Your evidence isn't good around here. A moderator of this forum has branded you to be a compulsive liar, and you have blatantly lied in previous threads.

I'm still waiting for Tom to explain my apparent misunderstanding of polar azimuthal projections and how, contrary to popular belief, you can make straight-line measurements on them and compare any two different parts of the projection without fear of distorted results.
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on February 04, 2021, 08:59:32 PM
Quote from: JSS
I finally got a clear night and managed to capture some star trails.

Your evidence isn't good around here. A moderator of this forum has branded you to be a compulsive liar, and you have blatantly lied in previous threads.

I'm still waiting for Tom to explain my apparent misunderstanding of polar azimuthal projections and how, contrary to popular belief, you can make straight-line measurements on them and compare any two different parts of the projection without fear of distorted results.

This was addressed to you without answer:


Nope, I wasn't wrong at all. I looked as Stellarium and couldn't find circular star trails.

So you’re standing by taking linear measurements on a picture which has the normally flat line of the horizon wrapped around in a circle? You don’t see a problem with that exercise?

No. I just see a misunderstanding of the polar projection, and planispheres. If you were representing the 180 degree view of the sky on a piece of paper you would do so on a circle.

Indeed you might choose to do that. But if you were to attempt to use a ruler to try to infer the angle subtended at the eyes of an observer between any two points, then other than cases involving measurement from the centre of the azimuthal projection, you will get a wrong answer. As you have done in your example.

You don’t need to even understand azimuthal projections to grasp this - it’s pretty obvious if you think about it.

I would need to see more evidence that it is impossible to portray the shapes an observer sees when looking up at the domed concave celestial sky onto a flat circular plane.

Here is an inverse example with a RE globe. If you are looking down at a globe and saw the great lakes in the shape of a circle for argument's sake (drawn orange circle), why don't you think that this circular shape can be maintained in a projection?

https://gisgeography.com/azimuthal-projection-orthographic-stereographic-gnomonic/

(https://i.imgur.com/tbEJBvr.png)

It literally says that this projection simulates what the observer would see from that position over the globe.

If the observer is hovering over the globe (if it was a globe) and sees the shape of a circle in the United States (orange circle) from that position, why shouldn't it also be a circle in the associated flat projection described?
Title: Re: How does FE explain star trails?
Post by: JSS on February 04, 2021, 09:16:44 PM
Quote from: JSS
I finally got a clear night and managed to capture some star trails.

Your evidence isn't good around here. A moderator of this forum has branded you to be a compulsive liar, and you have blatantly lied in previous threads.

I fail to see how a moderator calling me a liar makes it so. That's using the Appeal to Authority logical fallacy.

I have presented my evidence, you may choose to believe it or not, or if you want to challenge it, then point out any evidence in the image that backs up your claim.

I stand by my work, and the image showing circular star trails.  You are also free to conduct this experiment yourself to verify my results.
Title: Re: How does FE explain star trails?
Post by: SteelyBob on February 04, 2021, 10:44:00 PM
Quote from: JSS
I finally got a clear night and managed to capture some star trails.

Your evidence isn't good around here. A moderator of this forum has branded you to be a compulsive liar, and you have blatantly lied in previous threads.

I'm still waiting for Tom to explain my apparent misunderstanding of polar azimuthal projections and how, contrary to popular belief, you can make straight-line measurements on them and compare any two different parts of the projection without fear of distorted results.

This was addressed to you without answer:


Nope, I wasn't wrong at all. I looked as Stellarium and couldn't find circular star trails.

So you’re standing by taking linear measurements on a picture which has the normally flat line of the horizon wrapped around in a circle? You don’t see a problem with that exercise?

No. I just see a misunderstanding of the polar projection, and planispheres. If you were representing the 180 degree view of the sky on a piece of paper you would do so on a circle.

Indeed you might choose to do that. But if you were to attempt to use a ruler to try to infer the angle subtended at the eyes of an observer between any two points, then other than cases involving measurement from the centre of the azimuthal projection, you will get a wrong answer. As you have done in your example.

You don’t need to even understand azimuthal projections to grasp this - it’s pretty obvious if you think about it.

I would need to see more evidence that it is impossible to portray the shapes an observer sees when looking up at the domed concave celestial sky onto a flat circular plane.

Here is an inverse example with a RE globe. If you are looking down at a globe and saw the great lakes in the shape of a circle for argument's sake (drawn orange circle), why don't you think that this circular shape can be maintained in a projection?

https://gisgeography.com/azimuthal-projection-orthographic-stereographic-gnomonic/

(https://i.imgur.com/tbEJBvr.png)

It literally says that this projection simulates what the observer would see from that position over the globe.

If the observer is hovering over the globe (if it was a globe) and sees the shape of a circle in the United States (orange circle) from that position, why shouldn't it also be a circle in the associated flat projection described?

Tom, you do realise that diagram actually contradicts your own argument, don’t you?

Look at the latitude lines on the globe - they are equally spaced. Now look at them then on the projection. They are not equally spaced, are they? The areas close to the pole are quite accurately represented, but the closer you get the equator, the more compressed everything gets.

That’s why you can’t measure distances on a projection like that.

And you posted that, not me. Thank you.

So, again, do you now concede that your pixel measuring exercise was incorrect in its conclusions?
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on February 04, 2021, 11:52:04 PM
Quote from: SteelyBob
Look at the latitude lines on the globe - they are equally spaced. Now look at them then on the projection. They are not equally spaced, are they?

If you look at a globe the latitude/longitude lines aren't equally spaced. They are distorted and foreshorten from the center due to perspective.

The below example of this projection clearly says that it simulates the view of a globe, and what we would see:

https://courseware.e-education.psu.edu/projection/chap4figs.html#4

(https://i.imgur.com/SNKK9zh.png)

Is says that the projection simulates what an observer would see when looking at a sphere.

Why is it not possible to correctly translate shapes on the globe that the observer sees from a particular position over the globe to a 2D image?

(https://i.imgur.com/uJhNHZJ.png)

So, again, do you now concede that your pixel measuring exercise was incorrect in its conclusions?

No. You are mistaken in your understanding of this.

I fail to see how a moderator calling me a liar makes it so. That's using the Appeal to Authority logical fallacy.

Since you admit that an authority has branded you to be a compulsive liar, I really see nothing further to discuss. I generally agree with that moderator's decisions, and agree that this determination that you are a liar is accurate as well.
Title: Re: How does FE explain star trails?
Post by: JSS on February 05, 2021, 12:18:39 AM
I fail to see how a moderator calling me a liar makes it so. That's using the Appeal to Authority logical fallacy.

Since you admit that an authority has branded you to be a compulsive liar, I really see nothing further to discuss. I generally agree with that moderator's decisions, and agree that this determination that you are a liar is accurate as well.

Yes, I admit that Pete called me a liar.  I don't see how that has any bearing on my actually being a liar.  His word has no more weight in an argument than anyone elses.

You're still using an Appeal to Authority, which is a logical fallacy and therefore invalid for dismissing my evidence.  Since you have not presented any other arguments or evidence to show my photos are not genuine, I'm afraid your entire claim has failed and the photo continues to show that stars do make circular trails.
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on February 05, 2021, 12:20:05 AM
I fail to see how a moderator calling me a liar makes it so. That's using the Appeal to Authority logical fallacy.

Since you admit that an authority has branded you to be a compulsive liar, I really see nothing further to discuss. I generally agree with that moderator's decisions, and agree that this determination that you are a liar is accurate as well.

Yes, I admit that Pete called me a liar.  I don't see how that has any bearing on my actually being a liar.  His word has no more weight in an argument than anyone elses.

You're still using an Appeal to Authority, which is a logical fallacy and therefore invalid for dismissing my evidence.  Since you have not presented any other arguments or evidence to show my photos are not genuine, I'm afraid your entire claim has failed and the photo continues to show that stars do make circular trails.

Appeal to Authority Fallacy is only really a fallacy if the person is unqualified. I am fairly sure that they are qualified enough to determine whether or not you have lied to them.
Title: Re: How does FE explain star trails?
Post by: JSS on February 05, 2021, 12:33:47 AM
I fail to see how a moderator calling me a liar makes it so. That's using the Appeal to Authority logical fallacy.

Since you admit that an authority has branded you to be a compulsive liar, I really see nothing further to discuss. I generally agree with that moderator's decisions, and agree that this determination that you are a liar is accurate as well.

Yes, I admit that Pete called me a liar.  I don't see how that has any bearing on my actually being a liar.  His word has no more weight in an argument than anyone elses.

You're still using an Appeal to Authority, which is a logical fallacy and therefore invalid for dismissing my evidence.  Since you have not presented any other arguments or evidence to show my photos are not genuine, I'm afraid your entire claim has failed and the photo continues to show that stars do make circular trails.

Appeal to Authority Fallacy is only really a fallacy if the person is unqualified. I am fairly sure that they are qualified enough to determine whether or not you have lied to them.

No, that's not how the Appeal to Authority Fallacy works.  Using someone not qualified would be the Appeal to False Authority Fallacy.  It doesn't actually matter if Pete's 'qualification' of being a forum moderator is valid or not, using that as the basis of your argument is still a fallacy.  Also, being a moderator of an internet forum does not give anyone extra qualifications or weight in their arguments.  They have the authority to enforce decisions, but that does not automatically make anything they say true. 

You are using the Appeal to Authority Fallacy twice here.  Once to claim that my pictures are false because Pete says I am a liar, and again to claim that Pete must be right because he is a moderator. Double fallacy.

Regardless, you have not shown any valid arguments why my photo should be dismissed, therefore it's still valid evidence that star trails are not ovals as you claim. They are very clearly circles.
Title: Re: How does FE explain star trails?
Post by: Longtitube on February 05, 2021, 09:43:47 AM
There is also no accounting for Tom arguing star trails are oval or elliptical, while the wiki article AATW quoted, which Tom created in 2019 and has subsequently edited on several occasions, insists star trails are circles. It’s difficult to take him seriously here.
Title: Re: How does FE explain star trails?
Post by: AATW on February 05, 2021, 10:16:18 AM
Appeal to Authority Fallacy is only really a fallacy if the person is unqualified. I am fairly sure that they are qualified enough to determine whether or not you have lied to them.
I honestly don't understand what you're arguing here.
Your Wiki, which you apparently wrote, says the stars go in circles. You're now saying they don't.
Are you just arguing with anyone who says anything now even if it's something you previously claimed? ???

JSS has clearly demonstrated they do go in circles and your only counter argument is "pants on fire!". And while Pete and JSS have crossed swords, Pete has actively shown interest in JSS's astrophotography so there's no hint Pete things JSS is lying about this.

The fundamental problem you have is that in your model stars would actually only go in circles at the North Pole. You'd be at the centre of rotation looking up. From anywhere else the centre of rotation would be offset and because in your model the stars are relatively close you'd get an ellipse. The shape would vary by Latitude. That isn't what's observed.

Then we get to the problem of angular size where the stars are at significantly different distances through the night so would change angular size and luminosity. That isn't what's observed.

Then you have the issue of the star trails in different locations. At the equator they look like this.

(https://i.ibb.co/XFG3gWL/Star-Trail-Equator.png)

This is what you'd expect on a spinning ball, not what you'd expect if we're living on a plane with a disc of stars rotating above us.

Then you get into the Southern hemisphere issues where the axis of rotation is a southern point and the rotation is in the opposite direction. I see there's some half-baked explanation for that on the Wiki, a video by the aptly named P-Brane. But the explanation doesn't work. If you're looking up at a rotating disc and then look down at the same rotating disc then you will observe a different direction of rotation. That explanation doesn't work with a rotating disc which remains above you no matter your location.

TL;DR, your model of the stars and their movements doesn't match observable reality.
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on February 05, 2021, 10:51:45 AM
Quote
JSS has clearly demonstrated they do go in circles and your only counter argument is "pants on fire!". And while Pete and JSS have crossed swords, Pete has actively shown interest in JSS's astrophotography so there's no hint Pete things JSS is lying about this.

If you want to suggest that something is evidence I would suggest not citing someone branded to be a compulsive liar. You can't be a compulsive liar and expect that your evidence is trusted, regardless of subject.


It's fairly easy to see that the stars would seem to rotate clockwise when looking North and counter-clockwise when looking South in a FE model with stars passing overhead that appear from the observer's horizon.

(https://i.imgur.com/rEBKaT3.png)

When the observer looks North he he sees a counter clockwise curving from East to West. When he looks to the South he sees a clockwise curving from East to West.

There are also situations in which two celestial poles manifest. P-Brane's explanation is one of them, or it is found that when light comes in though a magnifying dome, it creates an opposite point of rotation.

https://wiki.tfes.org/Southern_Celestial_Rotation

https://www.youtube.com/watch?v=DWsWNsuP-KI&ab_channel=CuriousJ

Alternatively, there could be two celestial systems - https://wiki.tfes.org/Bi-Polar_Model
Title: Re: How does FE explain star trails?
Post by: AATW on February 05, 2021, 12:18:39 PM
If you want to suggest that something is evidence I would suggest not citing someone branded to be a compulsive liar. You can't be a compulsive liar and expect that your evidence is trusted, regardless of subject.
...says the man who hangs on Trump's every word, someone who told more demonstrable lies than any other President in history
But in any case I have seen other star trail photos, I have seen other time lapses. JSS's matches what I'd expect to see. And you know what, your philosophy is apparently to base your views on empirical observations so rather than trying to defame JSS how about you make your own observations if you doubt his results.

Quote
It's fairly easy to see that the stars would seem to rotate clockwise when looking North and counter-clockwise when looking South in a FE model

Incorrect. Because there only one centre of rotation which is the Northern hub.

(https://i.ibb.co/HVjW1dp/FEStar-Rotation.jpg)

Someone from point A - the North Pole would look up and see the stars going round in a circle above them - which matches observations, so far so good.
Someone at point B, roughly the equator, would see stars going in arcs but all in the same direction. You wouldn't get the arcs going in the shape showed in the photo above.
Someone at point C in, say, Australia, would also see arcs but with a wider radius. There is no other centre of rotation they would see the stars going around.

In the South if you're looking North you would see stars going from East to West and if you're looking South you'd see them going West to East. But they wouldn't be rotating around a Southern point in your model.

Quote
There are also situations in which two celestial poles manifest. P-Brane's explanation is one of them, or it is found that when light comes in though a magnifying dome, it creates an opposite point of rotation.
Alternatively, there could be two celestial systems - https://wiki.tfes.org/Bi-Polar_Model

So you're having to make up ad-hoc, unexplained mechanisms to make the observations fit your model?
Not very Occam's Razor, is it?
There is a model which explains all this very neatly of course...
Title: Re: How does FE explain star trails?
Post by: JSS on February 05, 2021, 12:29:02 PM
Quote
JSS has clearly demonstrated they do go in circles and your only counter argument is "pants on fire!". And while Pete and JSS have crossed swords, Pete has actively shown interest in JSS's astrophotography so there's no hint Pete things JSS is lying about this.

If you want to suggest that something is evidence I would suggest not citing someone branded to be a compulsive liar. You can't be a compulsive liar and expect that your evidence is trusted, regardless of subject.

This is just your Appeal to Authority again, and also an Ad hominem attack against my character.  Neither refute the image I posted, thus you have entirely failed to prove your point.

Stars go in circles, there is overwhelming evidence for this, including in your own wiki.

It's fairly easy to see that the stars would seem to rotate clockwise when looking North and counter-clockwise when looking South in a FE model with stars passing overhead that appear from the observer's horizon.

When the observer looks North he he sees a counter clockwise curving from East to West. When he looks to the South he sees a clockwise curving from East to West.

All I see are claims here.  I have not seen a simulation of this that accurately shows the movements of the stars.  You are simply stating that it is so. Has anyone created a computer simulation showing this effect and thus proven it is accurate?  Which FE map did they use for it?

There are also situations in which two celestial poles manifest. P-Brane's explanation is one of them, or it is found that when light comes in though a magnifying dome, it creates an opposite point of rotation.

https://wiki.tfes.org/Southern_Celestial_Rotation

Alternatively, there could be two celestial systems - https://wiki.tfes.org/Bi-Polar_Model

Situations where two poles manifest?  Do the Earths poles appear and disappear?

Looking at your Wiki pages, they add several more conflicting explanations. The stars are somehow distorted, or there are two 'gears' turning the sky in opposite directions, or it's distortion through a dome.

They can't all be right, and I do not see any computer simulations, math, equations or any details on how one can simulate the motion of the stars using any of these methods.

Once more, all I see are claims.  I see no evidence or theory backing up any of these claims, no measurements or predictions that match the observations of the sky.

This on the other hand, is direct photographic evidence that stars go in perfect circles.  The stars being very far away while the Earth rotates explains and predicts this motion exactly.

(https://i.imgur.com/XJiUnN4.jpg)
Title: Re: How does FE explain star trails?
Post by: AATW on February 05, 2021, 12:57:10 PM
The stars being very far away while the Earth rotates explains and predicts this motion exactly.
Ah yes. That's a point Tom failed to address. If the stars are small and close then the angular size and luminosity would vary greatly through the night as the distance varies greatly.
That is not what is observed.

Tom, your model claims that the stars are rotating in a disc above us. If they're moving anti-clockwise when you're looking from below then there is no possible way to see them rotating in the opposite direction from below no matter where you're looking at them from. If you look at them from above then yes, you'll see them rotating in the opposite direction but that isn't analogous to looking North and South from below the disc of stars.
Title: Re: How does FE explain star trails?
Post by: JSS on February 05, 2021, 01:00:08 PM
I have been thinking about how to prove stars move in perfect circles, no matter where you are on the planet and I think I have a simple, direct method to do so.

The Equatorial Telescope Mount

(https://www.spaceoddities.eu/wp-content/uploads/2018/08/equatorial-mount.jpg)

This is a very simple device, it's just shaft with a motor that turns the telescope in a circle, making one rotation every 24 hours.

When you point the axis of this motor at the north or south pole star, you can then mount your telescope to it, aim your telescope at a star and that star will remain perfectly centered in your viewfinder as the telescope is now rotating with the stars.

The key here is this mount simply rotates your telescope in a circle. That is all it does. It is physically a single axis, it's incapable of moving in anything BUT a circle. It literally can not turn in ovals or parabolas or any other shape, it is a single rotating axis. And it will keep any star you look at perfectly aligned.

This could not be possible if the stars did not also move in perfect circles.

There are hundreds of sites explaining how EQ mounts work and how to set them up if anyone wants to look them up. The EQ mount has been made and sold to millions of people around the world, it's widely used and so simple there can be little confusion on how it operates, and if it did not work as advertised, this would be well known by now.
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on February 05, 2021, 02:06:26 PM
Quote from: AllAroundTheWorld
...says the man who hangs on Trump's every word, someone who told more demonstrable lies than any other President in history

I don't see that we are talking about American politics in this thread. Sounds like you have quite an obsession. Fairly concerning considering considering that you aren't even an American citizen and live nowhere close to America.

Quote from: AllAroundTheWorld
So you're having to make up ad-hoc, unexplained mechanisms to make the observations fit your model?

It is hardly ad-hoc to the model. Bending light is already an established part of the FE model, and creates the domed observations. Light bending like through the glass dome would tend to fit with the rest of the model rather than be something radically different.

Quote from: AllAroundTheWorld
Incorrect. Because there only one centre of rotation which is the Northern hub.

It was demonstrated that it is possible to get two centers of rotation, so your assessment on what is possible is incorrect.

Quote
This is just your Appeal to Authority again, and also an Ad hominem attack against my character.

You don't have a good character. You have repeatedly gone into threads to make lies, and have been banned from this forum on multiple occasions.
Title: Re: How does FE explain star trails?
Post by: JSS on February 05, 2021, 02:54:46 PM
Quote
This is just your Appeal to Authority again, and also an Ad hominem attack against my character.

You don't have a good character. You have repeatedly gone into threads to make lies, and have been banned from this forum on multiple occasions.

Tom, could you at least try and quote properly?  For anyone following this thread, your habit of stripping out who said what makes your posts confusing to read. Thanks.

You can't use an Ad hominem attack to try and justify another.

Do not confuse your opinion with the truth, just because you claim I am a liar does not make it so.  You can claim I am a liar all you want, but that's just a claim, and is simply an Ad hominem attack to avoid debating my points with logic.

If I say 1+1=2, you can't claim that is wrong because you think I lied in the past.  You need to prove it. Calling me a liar is the lazy way out.

If I post a photo of circular star trails, unless you can show some evidence it's faked, what you think of my character doesn't matter.  Anyone can do the same experiment I did and validate my results.

I also posted about the EQ mount and how it shows that stars move in circles, all information there is also easy to verify.
Title: Re: How does FE explain star trails?
Post by: Pete Svarrior on February 05, 2021, 02:58:41 PM
Regardless of my opinions on JSS, I do not think it's reasonable to just call him a liar in response to everything he says (I said (https://forum.tfes.org/index.php?topic=17677.msg231118#msg231118) I'd step in if something like that were happening, and, in my view, it clearly is now).

Tom, please tone it down. I'm not asking you to trust JSS (and, by the looks of it, neither is he: "This experiment proves (if only to myself) that star trails are indeed circular."), but this is not productive in the upper.
Title: Re: How does FE explain star trails?
Post by: SteelyBob on February 05, 2021, 03:34:20 PM
Quote from: SteelyBob
Look at the latitude lines on the globe - they are equally spaced. Now look at them then on the projection. They are not equally spaced, are they?

If you look at a globe the latitude/longitude lines aren't equally spaced. They are distorted and foreshorten from the center due to perspective.

The below example of this projection clearly says that it simulates the view of a globe, and what we would see:

https://courseware.e-education.psu.edu/projection/chap4figs.html#4

(https://i.imgur.com/SNKK9zh.png)

Is says that the projection simulates what an observer would see when looking at a sphere.

Why is it not possible to correctly translate shapes on the globe that the observer sees from a particular position over the globe to a 2D image?

(https://i.imgur.com/uJhNHZJ.png)


They are equally spaced on the globe, that's the whole point. If you measure the distance between the latitude lines with a piece of string they are the same distance apart. Just like on the real planet, where 1 minute of latitude is 1nm. Now project that onto a flat map, and the foreshortening you describe happens. Now, if you try to measure the distance between the lines using a ruler, you will get a different result depending on where you measure on the map, with the results getting closer to the truth the closer to the middle of the projection you are. You can see that problem very clearly in the two projections shown in your example - countries close to the centre of the projection change apparent size when they are moved away from the centre in the other projection - look at, say, the width of the Baltic countries when they are centred and compare them with their apparent width when the centre is moved to Michigan - they come up narrower if you tried to use a ruler to measure their size.

And that's exactly the problem with your star projection - you can't use a ruler to measure the distance between pairs of stars when they are in different places on the projection - you'll get a different result, even if they are the same angular distance apart. Which of course they are, because they rotate in circles around the pole stars, as evidenced by Stellarium and every other star charting system, phone app, telescope controlling system, navigation chart, and just plain look-outside-and-see-for-yourself.

This is one of the most astonishing arguments I think I've ever seen online - you are confronted with a tidal wave of evidence, some of which you are even providing yourself, and you are still refusing to change your position. It's utterly stunning. Do you have a response, for example, to JSS's telescope mount point? They work really well, you know? And they would only work if the stars moved in circles. Doesn't that tell you something?

And thanks Pete, for stepping in. I have no interest in whether JSS is a liar or not, because he is not asking me to trust him. Calling him a liar in no way furthers your point, Tom - it merely looks like you are evading.   

[edited for a typo]
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on February 06, 2021, 09:31:42 PM
It goes both ways. If you are telling us that we can't trust random images because it's possible that they were modified then we can't trust random people who come to the forum who claim to have personal proof, because it is possible that it was modified.

In the first case you find it sufficient that you generally concede that you have no evidence that something was specifically modified, declaring it invalid because it is possible to be modified. In the second case you complain about evidence to see that something is modified, because it supports your belief to take that position. This sparks of hypocrisy.

Quote
They are equally spaced on the globe, that's the whole point. If you measure the distance between the latitude lines with a piece of string they are the same distance apart. Just like on the real planet, where 1 minute of latitude is 1nm. Now project that onto a flat map, and the foreshortening you describe happens. Now, if you try to measure the distance between the lines using a ruler, you will get a different result depending on where you measure on the map, with the results getting closer to the truth the closer to the middle of the projection you are. You can see that problem very clearly in the two projections shown in your example - countries close to the centre of the projection change apparent size when they are moved away from the centre in the other projection - look at, say, the width of the Baltic countries when they are centred and compare them with their apparent width when the centre is moved to Michigan - they come up narrower if you tried to use a ruler to measure their size.

No. You are asking us to compare the two different orthogonal projections (A) and (B) in the above image from psu.edu, centered on Michigan and the Baltic countries, and see that they look different. This has no analogy to the question of whether a shape that the observer sees in the sky can be represented on a flat plane.

There is only one position we are comparing to the sky in the Stellarium projection of the sky, centered at a particular location. This is analogous to only comparing the shapes we see when looking down at a globe while we are hovered over the globe centered over Michigan and the orthogonal projection (A) when centered over Michigan.
Title: Re: How does FE explain star trails?
Post by: stack on February 06, 2021, 09:54:25 PM
It goes both ways. If you are telling us that we can't trust random images because it's possible that they were modified then we can't trust random people who come to the forum who claim to have personal proof, because it is possible that it was modified.

In the first case you find it sufficient that you generally concede that you have no evidence that something was specifically modified, declaring it invalid because it is possible to be modified. In the second case you complain about evidence to see that something is modified, because it supports your belief to take that position. This sparks of hypocrisy.

No, two totally different scenarios. In the first, we just don't know if or how something was captured, modified, whathaveyou. In the second scenario it is explained if or how something was captured, modified, whathaveyou - You just don't believe the person.
Title: Re: How does FE explain star trails?
Post by: AATW on February 06, 2021, 10:37:17 PM
It was demonstrated that it is possible to get two centers of rotation, so your assessment on what is possible is incorrect.
If the light passes through a solid glass hemisphere. Not even close to analogous to our atmosphere.
And completely contradicts the P-brane video on your Wiki which is on the same page as the "glass dome" video.
You have two videos on the same Wiki page which offer alternative and contradictory explanations for the same observation.
The first just doesn't work. The second is using a solid glass dome which isn't optically anything like our atmosphere.
This is an admission that you can't explain it and are just inventing ad-hoc - indeed contradictory - mechanisms to explain the observation.
An observation which is expected - indeed predicted - by a globe earth.
Occam's razor would suggest that is the simpler, and therefore more likely to be correct, explanation.
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on February 07, 2021, 12:48:55 AM
It goes both ways. If you are telling us that we can't trust random images because it's possible that they were modified then we can't trust random people who come to the forum who claim to have personal proof, because it is possible that it was modified.

In the first case you find it sufficient that you generally concede that you have no evidence that something was specifically modified, declaring it invalid because it is possible to be modified. In the second case you complain about evidence to see that something is modified, because it supports your belief to take that position. This sparks of hypocrisy.

No, two totally different scenarios. In the first, we just don't know if or how something was captured, modified, whathaveyou. In the second scenario it is explained if or how something was captured, modified, whathaveyou - You just don't believe the person.

Nope, they are not two radically different scenarios. In one scenerio you have no evidence that it was modified and declare that something is invalid based on zero evidence that something was modified. You are insisting that it is possible that it was modified, so it is invalid.

People have come here to lie before, asserting to be whistleblowers and spies and astronauts and everything of the sort, who have some sort of personal evidence that proves their point. Why should we not feel free to discard that evidence to be invalid due to circumstance, regardless of whether they show us a piece of paper which has the word NASA on it?

It is enough for you to disregard something because of a possibility, and it is hypocritical to claim that something can't be disregarded for another possibility.
Title: Re: How does FE explain star trails?
Post by: JSS on February 07, 2021, 01:04:51 AM
It goes both ways. If you are telling us that we can't trust random images because it's possible that they were modified then we can't trust random people who come to the forum who claim to have personal proof, because it is possible that it was modified.

In the first case you find it sufficient that you generally concede that you have no evidence that something was specifically modified, declaring it invalid because it is possible to be modified. In the second case you complain about evidence to see that something is modified, because it supports your belief to take that position. This sparks of hypocrisy.

It's up to you if you want to disregard every bit of evidence that doesn't fit with your preconceived notions.

You are deliberately misconstruing the argument about random internet images. I never said you can't trust random people, I said if you don't know what lens a photo was taken with, what the settings were, what processing might have been done, then you can't use that photo as evidence that stars move in ovals.  It's not about trusting the image it's about the KNOWLEDGE and INFORMATION. You don't have either of those in this case.

Not because the photographer is a liar or dishonest, but because you do not have all the required information to determine if a curve is real or an artifact.  It's that simple.  You just don't know.

I trust my own photos because I took them, I know what lens I used, I know how I set it all up. There are no unknowns that could affect the outcome.

If you want to track down the photographers of all the pictures you used, ask them what lenses they used, what post processing they did, THEN you can use that image as evidence.

Otherwise you are just guessing and assuming, both which will lead you stray, as it has.

If you really want to know the truth about how stars move, read and try and understand my post on EQ mounts. That's solid proof right there, and you don't have to trust me at all. You can look it up yourself.
Title: Re: How does FE explain star trails?
Post by: stack on February 07, 2021, 01:07:21 AM
It goes both ways. If you are telling us that we can't trust random images because it's possible that they were modified then we can't trust random people who come to the forum who claim to have personal proof, because it is possible that it was modified.

In the first case you find it sufficient that you generally concede that you have no evidence that something was specifically modified, declaring it invalid because it is possible to be modified. In the second case you complain about evidence to see that something is modified, because it supports your belief to take that position. This sparks of hypocrisy.

No, two totally different scenarios. In the first, we just don't know if or how something was captured, modified, whathaveyou. In the second scenario it is explained if or how something was captured, modified, whathaveyou - You just don't believe the person.

Nope, they are not two radically different scenarios. In one scenerio you have no evidence that it was modified and declare that something is invalid based on zero evidence that something was modified. You are insisting that it is possible that it was modified, so it is invalid.

People have come here to lie before, claiming to be whistleblowers and spies and astronauts and everything of the sort. Why should we not feel free to discard that evidence to be invalid, regardless of whether they show us a piece of paper which has the word NASA on it?

It is enough for you to disregard something because of a possibility, and it is hypocritical to claim that something can't be disregarded for another possibility.

I have no idea what you're talking about. I'm not "insisting" anything. All I said is that we don't know ANYTHING about an image that is randomly plucked from a google image search. It may be modified, it may not. Who knows unless you can dig up info from the shooter or elsewhere.

As for someone posting an image they took and describing what was done to it, gear used, etc., sure, take it at face value. And based upon that descriptive nature of the image or whatever and how it was assembled, at least you may have a shot to credit it or discredit it based upon the claimed details. The same applies to anything anyone posts/claims. At least you have some info to jump off from. In the first scenario, you have nothing.
Title: Re: How does FE explain star trails?
Post by: JSS on February 07, 2021, 01:44:15 AM
The short version.

1. Do you have all the required information to make your determination?  In the case of a random internet image, no you do not.

2. If all the information is provided, do you trust the source?

Tom's images fall under category 1, mine under 2.

I can make sure 1 is covered when I post, but I can't do anything about 2.
Title: Re: How does FE explain star trails?
Post by: SteelyBob on February 07, 2021, 10:22:49 AM

No. You are asking us to compare the two different orthogonal projections (A) and (B) in the above image from psu.edu, centered on Michigan and the Baltic countries, and see that they look different. This has no analogy to the question of whether a shape that the observer sees in the sky can be represented on a flat plane.

There is only one position we are comparing to the sky in the Stellarium projection of the sky, centered at a particular location. This is analogous to only comparing the shapes we see when looking down at a globe while we are hovered over the globe centered over Michigan and the orthogonal projection (A) when centered over Michigan.

(https://i.imgur.com/lMNgngn.jpg)
(https://i.imgur.com/V1ph9zk.jpg)

Let's all remember - this is your analogy, and these are the two stellarium pictures you showed.

As can be clearly seen in the pictures, Polaris stays pegged in the same place, as we would expect, and everything else moves around it. And because everything has moved, they are no longer in the same place in the projection, which means the distance between them will change, even if their angular separation in the real sky remains the same. Just as the apparent width of the baltic states, or indeed any identifiable land mass, is different in those two globe projections, so it goes for the stars as well.

With every post, you go deeper into a hole of your own creation.

As an aside, I notice you've studiously avoided addressing JSS's point about the telescope mount, which is, frankly, one of the clearest and most obvious indications that stars move in circles. Aside from your own wiki post, of course...




Title: Re: How does FE explain star trails?
Post by: Tom Bishop on February 07, 2021, 04:18:22 PM
Incorrect. Another false comparison. The location is the same, only the time is different.

The Orthogonal projection preserves shapes from a particular viewpoint. It doesn't matter if the scene is animated or not. The projection will be able to preserve the shapes seen by the observer.
Title: Re: How does FE explain star trails?
Post by: JSS on February 07, 2021, 04:48:09 PM
Incorrect. Another false comparison. The location is the same, only the time is different.

The Orthogonal projection preserves shapes from a particular viewpoint. It doesn't matter if the scene is animated or not. The projection will be able to preserve the shapes seen by the observer.

What does it being animated or the time or location have anything to do with the problem that you can not measure distances on an orthogonal projection of a sphere as if it were a plane?

The issue at hand here is you are taking screenshots which are orthogonal projections of a sphere onto a plane, and trying to measure distances. This as you have seen does not work as the scale changes as you move away from the origin.  You can see the distortion in the trees and ground all curving inward.

Remember that the equation for orthogonal projection of a sphere uses transcendental functions, these are NOT linear, thus the result can't me measured as if they are.  This is this base mistake you are making.

All of which is still pointless to discuss since you have not addressed my EQ mount argument, which shows very simply that stars do move in circles, not ovals.
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on February 07, 2021, 04:57:56 PM
On telescope mounts, from an astronomy forum we read that a standard equatorial mount has limited use. Why should we believe your forum assertions over this person's?

https://www.cloudynights.com/topic/410655-equatorial-mount-for-beginner-and-other-advice/

Posted 13 March 2013 - 11:03 AM

"I'm a bit late to the thread, but my two cents on the 8SE: I'm relatively new to the hobby and the 8SE was my first purchase about a month ago. I think it's an amazing telescope for a newbie, but I quickly found myself wanting to photograph everything. The Alt/az mount it comes with can really only handle about 30-45 seconds of tracking an image to the point where stars aren't ovals. So getting those nice 300-600 second exposures I see some get here is not doable.

With that said, it's my first scope and I plan on enjoying this hobby for many more decades, so there will be time to get bigger and better. Going from just my two eyeballs to a nice 8" telescope is more than enough to keep me busy for good while.

Now I just need to find a good dark site to take it..."

Clearly an issue if some telescopes can handle 35 seconds and others 300 seconds.
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on February 07, 2021, 05:08:56 PM
Quote
You are misunderstanding what you read on that web page, perhaps you should look up more sources than a forum post from a new user who   

Once more, you are putting words into my mouth.  Where did I ever make claims about how useful or not basic entry level telescope mounts are?

The basic problem you seem to have here is you are confused about the limits of precision for cheap, hobby level equipment.

The other issue is you are confused over him saying 'oval stars' and you claim of 'oval star trails'.  This is due to the cheap mount not being stable and causing the telescope to not track accurately, causing teh stars to appear as a blur instead of sharp points.  A good setup will easily fix this problem, I can take 15-30 minute exposures with mine.

So in summary, you found someone complaining that their entry level telescope doesn't track as well as a professional scope.  This is both unsurprising, and has nothing to do with my argument, the quote does not conflict with anything I have said, once you look closer and understand it.

Did you really just Google 'oval' and 'EQ mount' and post the first quote you could find?  ::)

Sorry, I don't see how your anonymous post is any more credible than another anonymous post.
Title: Re: How does FE explain star trails?
Post by: JSS on February 07, 2021, 05:11:27 PM
On telescope mounts, from an astronomy forum we read that a standard equatorial mount has limited use. Why should we believe your forum assertions over this person's?

https://www.cloudynights.com/topic/410655-equatorial-mount-for-beginner-and-other-advice/

Posted 13 March 2013 - 11:03 AM

"I'm a bit late to the thread, but my two cents on the 8SE: I'm relatively new to the hobby and the 8SE was my first purchase about a month ago. I think it's an amazing telescope for a newbie, but I quickly found myself wanting to photograph everything. The Alt/az mount it comes with can really only handle about 30-45 seconds of tracking an image to the point where stars aren't ovals. So getting those nice 300-600 second exposures I see some get here is not doable.

With that said, it's my first scope and I plan on enjoying this hobby for many more decades, so there will be time to get bigger and better. Going from just my two eyeballs to a nice 8" telescope is more than enough to keep me busy for good while.

Now I just need to find a good dark site to take it..."

The EQ mounts clearly aren't all circular if some can handle 35 seconds and others 300 seconds.

Tom, look at the bold part of your quote.

He is talking about an Alt/az mount, not an equatorial mount.  They are completely different things.

It really looks like you just Googled 'oval' and 'eq mount' and copy-pasted the first quote you could find without reading or understanding it.

Besides, nothing in that quote contradicts anything I said.  Nobody has to choose to believe me over them because they are both true.

The other issue is you are confused over him saying 'oval stars' and your claim of 'oval star trails'.  He's talking about the stars being blurry shapes due to the lack of tracking precision.

Title: Re: How does FE explain star trails?
Post by: Tom Bishop on February 07, 2021, 05:19:18 PM
He is talking about an Alt/az mount, not an equatorial mount.  They are completely different things.

I don't see the relevance. All components of a telescope need to be sufficient for star tracking. If some telescope users can only get 45 seconds and others 400 seconds, I don't see how it supports your case that we can just buy a telescope and track a star accurately all night long.

Please show direct third party evidence that the stars are trackable for long duration.

Quote
The other issue is you are confused over him saying 'oval stars' and your claim of 'oval star trails'.  He's talking about the stars being blurry shapes due to the lack of tracking precision.

No, lack of tracking precision wouldn't cause the telescope to become out of focus. It is clear what is being described there.
Title: Re: How does FE explain star trails?
Post by: JSS on February 07, 2021, 05:28:37 PM
He is talking about an Alt/az mount, not an equatorial mount.  They are completely different things.

I don't see the relevance. All components of a telescope need to be sufficient for star tracking. If some telescope users can only get 45 seconds and others 400 seconds, I don't see how it supports your case that we can just buy a telescope and track a star accurately all night long.

Please show direct independent evidence that the stars are trackable for long duration.

Do you not understand the difference between an Alt/az mount and an equatorial mount?

The relevance should be blindingly obvious to anyone what does. The equatorial mount spins on it's axis in a circle to track the stars, the Alt/az mount does not.

You are confused that some users get better tracking with a telescope mount DESIGNED FOR BETTER TRACKING rather than a telescope designed to be cheap? Why is this a point of confusion for you?  If you want long term tracking, buy a mount designed for that.

Now you want to go down the rabbit hole of proving to you that telescopes can track stars for a 'long' duration.  Fine, but please specify what 'long' is so I don't waste my time, thanks.
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on February 07, 2021, 05:42:01 PM
You haven't provided any evidence that third parties are able to track stars all night long. You are only providing an interpretation of what you think is happening, and simply declaring what is possible. Some people are clearly having issues with their equipment, so your suggestion that we should buy random equipment and give it a try is invalid.

Show us the people who are not having issues, and have accurately tracked stars all  throughout the night.
Title: Re: How does FE explain star trails?
Post by: Kokorikos on February 07, 2021, 05:48:24 PM
I think that we can all agree that the process that JSS followed to get his photos of the circular star trails is easily reproducible.

Why doesn't anyone else do the same to check the validity of his results?
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on February 07, 2021, 05:54:34 PM
Another reference, see bolded:

https://www.astropix.com/html/i_astrop/tracked/polar.html

"'Equatorial' telescope mountings have two axes, a polar axis and a declination axis, to help compensate for the Earth's rotation and aim at objects in different parts of the sky.

~

Use of a polar alignment scope built into the mount will help speed up alignment, but "drift" aligning will probably also be necessary for critical work.

A star that is monitored at high power (200x) in a guiding eyepiece with cross hairs most probably will not stay in one exact location in the field. There are several different reasons for this.

The star will usually seem to bump around a bit if the seeing is not that good. It can move all over the place on a very short time frame if the seeing is really bad.

Even if the seeing is excellent, the star will slowly drift from its original location. It can drift east - west due to inaccuracies in the right ascension gear and drive train that move the telescope to compensate for the Earth's rotation.

This is normally associated with periodic error, so called because the error in drift will coincide with the period of rotation of the worm gear. If a star is carefully monitored, the star will move one way for about 1/2 of the period of the worm, and then move back the other direction until it has returned to its starting position. This movement will usually be gentle and slow, but there can be quick jerks and movements from erratic error depending on the quality of the worm, gear, and components. For excellent mounts, this periodic error can be as little as a few arc seconds. For mediocre mounts, it can be as large as several minutes of arc.

For long-exposure deep-sky astrophotography, this periodic error must be guided out by either manually by the photographer with a high-power cross hair eyepiece or automatically with a CCD auto-guider such as the SBIG ST-4 or STV.

If the mount is not polar aligned to good accuracy, there will also be a slow north or south drift in declination.

Drift polar aligning is accomplished by monitoring the declination drift of a star at high power in the eyepiece and adjusting the polar axis of the mount based on the direction of drift.

Two corrections are necessary based on two observations: one of a star on the meridian for the azimuth of the polar axis of the mount, and one of a star near the eastern or western horizon for the elevation of the polar axis.

While monitoring the drift, any east - west movement is ignored or guided out by corrections in right ascension only. It is important that no corrections be made in any north - south declination drift because this drift will indicate which we have to move the mount to achieve more accurate polar alignment."
Title: Re: How does FE explain star trails?
Post by: JSS on February 07, 2021, 05:58:58 PM
You haven't provided any evidence that third parties are able to track stars all night long. You are only providing an interpretation of what you think is happening, and simply declaring what is possible. Some people are clearly having issues with their equipment, so your suggestion that we should buy random equipment and give it a try is invalid.

Show us the people who are not having issues, and have accurately tracked stars all  throughout the night.

Tom, I said to use an equatorial mount, and you found someone having problems with an Alt/az mount.  Please learn the difference and why one tool is better than another for some purposes.

One of these mounts is designed for long term star tracking, the other is not. 

If I tell you to buy a screwdriver and you find people having trouble with hammers, how is that at all relevant?

You are clearly able to use Google, so I'm confused how you are unable to look up the ability of equatorial mount telescopes to track stars.

But if you would like me to do it for you I ask again, and please answer this time, what do you mean by proving they can track for a 'long' time?  And why do you need to track them all night?  An hour is plenty of time to get a good star trail picture.

Title: Re: How does FE explain star trails?
Post by: JSS on February 07, 2021, 06:04:14 PM
Even if the seeing is excellent, the star will slowly drift from its original location. It can drift east - west due to inaccuracies in the right ascension gear and drive train that move the telescope to compensate for the Earth's rotation.

You got the right telescope mount this time at least.

But you still are confused about precision and physical limitations. The star drifts because of 'inaccuracies in the right ascension gear and drive train' not because the stars themselves are moving in ovals.

Your quote clearly indicates the errors are due to the limits of quality and tolerance in the equipment.

I'd also like to point out the other statement in your quote, 'to compensate for the Earth's rotation'. Your own source is also clearly indicating that the stars do rotate in circles, as they would on a rotating Earth.
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on February 07, 2021, 06:12:06 PM
The above quote was from an authoritative source astropix.com which says that even with excellent conditions there will still be drift with this sort of equipment.

None of this is compelling evidence that this equipment can accurately track a star all night long.

You have provided no legitimate evidence for this established nature of EQ mounts you were trying to pawn off.

You even resort to bolding "earth's rotation" as your center piece, because your level of evidence for this is weak.
Title: Re: How does FE explain star trails?
Post by: JSS on February 07, 2021, 06:26:59 PM
The above quote was from an authoritative source astropix.com which says that even with excellent conditions there will still be drift with this sort of equipment.

None of this is compelling evidence that this equipment can accurately track a star all night long.

You have provided no legitimate evidence for this established nature of EQ mounts you are trying to pawn off.

You even resort to bolding "earth's rotation" as your center piece, because your level of evidence for this is weak.

I'm not trying to pawn off anything, millions of people use equatorial mount telescopes to track stars successfully.  Your only argument is you demand 100% accuracy?

You haven't explained why needing to track a star 'all night long' is required for you to believe a telescope can track stars?

Do you understand how precision works? No matter how precise you make a piece of physical equipment, there are always tolerances it will fail at.

No matter how much money you spend or how carefully building, anything physical will have physical errors and limitations.  Nothing in the world is 100% perfect.

You seem to be suggesting that if a telescope can 'only' track for 10 hours and not 10 hours and 1 second, then it can't track the stars at all?

You keep asking me to prove telescopes can track stars, but continue to refuse to narrow down your request so I can do so.

1. How many hours do you need for proof?

2. What amount of magnification?

My scope can certainly track stars all night long if I have a wide angle lens.  Less if I start to zoom in.


Title: Re: How does FE explain star trails?
Post by: Tom Bishop on February 07, 2021, 06:46:39 PM
It doesn't say anything about being accurate for ten hours. Find authoritative third party evidence which says that long-term tracking of the stars with an EQ mount has occured. You have provided nothing at all, except for your insistence that it is possible.
Title: Re: How does FE explain star trails?
Post by: JSS on February 07, 2021, 06:52:24 PM
It doesn't say anything about being accurate for ten hours. Find third party evidence which says that long-term tracking of the stars with an EQ mount is possible. You have provided nothing at all, except for your insistence that it is possible.

Tom, you demanding 100% accuracy is unreasonable.  I already explained that nothing physical at all is ever 100% accurate, nothing.

So why are you demanding equilateral mounts be absolutely perfect?  Can you at least acknowledge that you understand that nothing can be made perfectly accurate?  That's an important concept you need to understand first before we go further.

And why this ten hour magic number?  If I find a scope that can track for 9 hours you will reject it, but if I find one for 10 hours then you will accept it?  Why?  What's your method for determining that then hours is the required tracking time?  It seems like you just picked an arbitrarily high number.  Can you provide a reference, or show your math for why you picked ten hours?

You need to understand that at 10 hours, even the heating and cooling of the metal of the stand and the surface it rests on is going to make the tracking drift.  I don't think you fully comprehend the tolerances at play here.

You are demanding I prove something that is done by thousands of people around the world every single night.  If you want third party evidence, look it up.  If you still can't find it, I'll try and help.  But you need to be able to explain what you are looking for.
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on February 07, 2021, 07:01:38 PM
The page doesn't say anything about being accurate for 10 hours, or 9 hours either. You are the one who keeps trying to insist that it's accurate for long duration. You haven't shown that it's accurate for any length of time.

Where are the references and evidence showing that long duration tracking of a star with an EQ mount has occured?
Title: Re: How does FE explain star trails?
Post by: JSS on February 07, 2021, 07:06:00 PM
The page doesn't say anything about being accurate for 10 hours, or 9 hours either. You are the one who keeps trying to insist that it's accurate for long duration. You haven't shown that it's accurate for any length of time.

Where are the references and evidence showing that long duration tracking of a star with an EQ mount has occured?

So you will only accept the fact that equatorial mounts can track the stars if you can find third party evidence that it can track for 10 hours?  No less?

How much precision is required?  How much error due to mechanical tolerances will you accept?
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on February 07, 2021, 07:56:24 PM
$700 Equatorial Mount - https://www.amazon.com/gp/product/B07NY44782/

https://www.amazon.com/gp/product/B07NY44782/ref=ask_ql_qh_dp_hza

"Question: When polar aligned north, can you use a ball head mount to rotate your camera 180* to capture the southern sky without trailing?

Answer: Hi Doyle, YES! Once the head is aligned, move your camera wherever and it will track the object for up to 5 minutes when using a wide-angle the lens. A telephoto (200mm) can only go about 2 minutes."

Seems to suggest that this $700 EQ mount can only track stars for up to 5 minutes.
Title: Re: How does FE explain star trails?
Post by: JSS on February 07, 2021, 08:05:12 PM
$700 Equatorial Mount - https://www.amazon.com/gp/product/B07NY44782/

From the Q&A:

https://www.amazon.com/gp/product/B07NY44782/ref=ask_ql_qh_dp_hza

"Question: When polar aligned north, can you use a ball head mount to rotate your camera 180* to capture the southern sky without trailing?

Answer: Hi Doyle, YES! Once the head is aligned, move your camera wherever and it will track the object for up to 5 minutes when using a wide-angle the lens. A telephoto (200mm) can only go about 2 minutes."

Seems to suggest that this $700 EQ mount can only track stars for up to 5 minutes.

What exactly is the point you are trying to make here? A mid-level telescope without a solid stand is going to give you 2-5 minutes of tracking which is quite good for near entry level equipment.  If you think $700 is expensive, you have not seriously shopped for astronomy equipment.  If you think 'on;y' 5 minutes is terrible, it means you don't understand the precision required for more.

You seem to be thinking that after 5 minutes the stars will go veering widely out of the view frame, this is wrong.  I'm not sure what you imagine is going on here, but you are not understanding what they mean when they say it can only track for 5 minutes.

What happens is after 5 minutes the inaccuracies are enough to make the stars blurry, which ruins the image.  Usually the errors are cyclical, which results in fuzzy stars, but the stars do not go careening wildly all over the image frame.  At the end of even several hours, the stars will still be quite well aligned in the viewfinder/camera.

You bolded 'move your camera wherever' which seems you indicate you don't understand this either.

Your own source here states quite clearly the mount DOES track the stars, it just has limits for how steady it is and that the jitter will start to blue stars after a few minutes.  This in no way means it can't track the stars, nor does it means stars travel in ellipses.
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on February 07, 2021, 08:23:01 PM
Quote
What happens is after 5 minutes the inaccuracies are enough to make the stars blurry, which ruins the image.  Usually the errors are cyclical, which results in fuzzy stars, but the stars do not go careening wildly all over the image frame.  At the end of even several hours, the stars will still be quite well aligned in the viewfinder/camera.

It doesn't say that in the link.

Once more, you continue to provide zero sources on this assertion that these mounts have accurately followed stars over long duration.
Title: Re: How does FE explain star trails?
Post by: JSS on February 07, 2021, 08:23:40 PM
Quote
What happens is after 5 minutes the inaccuracies are enough to make the stars blurry, which ruins the image.  Usually the errors are cyclical, which results in fuzzy stars, but the stars do not go careening wildly all over the image frame.  At the end of even several hours, the stars will still be quite well aligned in the viewfinder/camera.

It doesn't say that in the link.

Once more, you continue to provide zero sources on this assertion that these mounts can accurately follow stars over long duration.

Yes it does say that, you just don't understand enough to understand the context. You are looking at these pages and discussions made by people who actually use this equipment and are making a lot of assumptions based on ignorance of the subject.

Your insistence on a 'long duration' doesn't prove they don't track stars, it just means you don't understand the precision alignment required to track stars with extreme precision without any drift that can be seen by today's high resolution sensors.  You really should look at the numbers on just HOW accurate these devices are.  Saying you 'only' get 5 minutes before the stars start to blue shows you don't really understand this.
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on February 07, 2021, 08:58:17 PM
Yes it does say that

Quote it then. You are merely coming up with "explanations" which are stated nowhere in the text.

Once again, you continue to provide zero evidence from third party sources that stars have been tracked for long duration.
Title: Re: How does FE explain star trails?
Post by: JSS on February 07, 2021, 09:22:06 PM
Yes it does say that

Quote it then. You are merely coming up with "explanations" which are stated nowhere in the text.

Once again, you continue to provide zero evidence from third party sources that stars have been tracked for long duration.

He said you can track stars for between 2-5 minutes.  This means it takes 2 to 5 minutes to drift enough to be noticeable on a high resolution camera. It does NOT mean the stars just veer into massive oval shapes or go wandering all over.  Your source backs me up that equatorial mounts do indeed track stars, and go in circles.

You are the one making unreasonable and vague demands that they track them for '10 hours' without giving any other specifics like error allowed and what kind of drift you find acceptable.

Let me try and explain so you can understand what's going on and why you are wrong here.

When you align an equatorial mount telescope you have to align the main axis perfectly with the rotation of the earth/sky.  Just aiming it at the pole star isn't good enough as the pole star is close, but not exactly in the center.  You can see this in the image I posted.

Note that this is NOT aiming the telescope!  This is lining up the actual motor and shaft of the mount, a much harder process to eyeball.

Once you think you have your mount leveled and aimed correctly, you attach your camera/telescope to it and take a long exposure. It's going to have drift because you didn't get it perfectly aligned, so you adjust it and try again. This process can take up to an hour depending on hos precise you want.

How precise is it?  Lets take that 2 minute exposure of the $700 telescope you googled.  Using an APS-C format DSLR and a 200mm lens as described, each pixel of the sensor covered 0.0008 degrees of the sky.  So that means in 2 minutes, that mount needs to rotate with THAT degree of accuracy.

So when they say they can 'only' get 2 minutes of shutter time, they mean it can keep it's alignment to within 1/10,000th of a degree over 2 minutes.  That is VERY good for $700 without a heavy duty tripod.

And you want ten hours!  That's just nuts.

Do you see why this is a unreasonable demand of yours?  You don't understand what you're even asking for.

And let me remind you that there are multiple sources of error from the various worm and normal gears. Some of that error is cyclic, other is linear. Every mount and motor will be different, different camera and telescope weights and how they are distributed will alter this error and how it is perceived.

If you take the worst case and all the error ends up pushing it off in the same direction, after ten hours that mount will only be off by less than 1/2 a degree. 

This is for a 'cheap' $700 scope sold without a heavy duty tripod.  More money gets you even higher precision. 
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on February 07, 2021, 09:35:30 PM
No, I don't want rambling explanations from a random person on the internet, which is not stated in the text, and is of questionable veracity.

I want citations from authoritative sources that the EQ mount has tracked stars over long duration.
Title: Re: How does FE explain star trails?
Post by: stack on February 07, 2021, 09:36:37 PM
Yes it does say that

Quote it then. You are merely coming up with "explanations" which are stated nowhere in the text.

Once again, you continue to provide zero evidence from third party sources that stars have been tracked for long duration.

Here's a neat one:

Earth's Rotation Visualized in a Timelapse of the Milky Way Galaxy - 4K
https://youtu.be/1zJ9FnQXmJI

A timelapse of the Milky Way that was recorded using an equatorial tracking mount over a period of around 3 hours to show Earth's rotation relative to the Milky Way.
Gear Used:
Camera https://amzn.to/33aQRe6​
Lens https://amzn.to/39MCZt3​
Lens Adapter https://amzn.to/2wNi4Yi​
Tripod https://amzn.to/2vjN8i4​
Tracking Mount https://amzn.to/39GOQc6​
Intervalometer https://amzn.to/3aKRBJB​
External Battery https://amzn.to/39UPkM5​

EXIF: 24mm, 10", F/2.8, 16000iso.
Title: Re: How does FE explain star trails?
Post by: JSS on February 07, 2021, 09:46:09 PM
No, I don't want rambling explanations from a random person on the internet, which is not stated in the text, and is of questionable veracity.

I want citations from authoritative sources that the EQ mount has tracked stars over long duration.
I'm trying to explain how these work, I'm trying to teach you something but I can only provide the information, I can't make you understand it.  That's up to you.

If posting Wiki links is the only valid method of debate acceptable to you, then here you go.  Do your own research. https://en.wikipedia.org/wiki/Equatorial_mount

Stack posted a video, long-term tracking on an equatorial mount.  Is that good enough?

https://youtu.be/1zJ9FnQXmJI
Title: Re: How does FE explain star trails?
Post by: SteelyBob on February 07, 2021, 10:04:09 PM
No, I don't want rambling explanations from a random person on the internet, which is not stated in the text, and is of questionable veracity.

I want citations from authoritative sources that the EQ mount has tracked stars over long duration.

The internet is littered with excellent explanations of EQ mount errors. They explain very clearly what JSS is saying - you can't infer long-term error from the exposure lengths being discussed for several reasons. As JSS says, for a start the errors involved are tiny. Moreover, a big chunk of the error is periodic, meaning it might trash a long-isn exposure of a few minutes, but it will be no worse over 2 hours than 2 minutes.

Here's an interesting one I found very quickly by searching for 'EQ mount errors'.

http://www.pk3.org/Astro/index.htm?astrophoto_mount_errors.htm (http://www.pk3.org/Astro/index.htm?astrophoto_mount_errors.htm)

The authors measures tracking error on their rig and breaks out the linear error from the periodic. The linear error looks to be around 150 arc seconds over 20 minutes, which is therefore 4500 arc seconds over 10 hours, or 1.25 degrees. That's pretty respectable, given that typical visible constellations are several degrees across - Orion is roughly 10 x 20 degrees - and way, way less than we would expect if the stars were moving in some kind of ellipse.

If the stars were moving elliptically, I'm pretty sure one of the millions of people who look at the stars for fun, or for a living, would have made a name for themselves inventing an elliptical tracking mount. But they haven't, have they?

I'd also point to the many 'go to' mounts you can buy, which use the same logic, based on the earth's rotation and the observer's location, to quickly move the scope to points of interest in their database.

(http://www.pk3.org/Astro/Images/Theory/MountErrors/polar_align+periodic_error.gif)
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on February 07, 2021, 10:30:41 PM
The mount in that video is an advanced tracking mount like described would be necessary on the astropix.com site. It isn't merely a motor that goes in a circle. It can be connected to computers, uses cameras for tracking, and has add-ons that track and guide.

https://www.altairastro.com/ioptron-skyguider-pro-camera-mount-full-package-2227-p.asp

"For more advanced users who want extra-long exposures and or have longer focal length lenses, the built-in autoguiding port allows even more accurate tracking with an external guide camera such as the popular Altair GPCAM2 Mono."

There is another device in that package that has a camera as well: https://optcorp.com/products/ioptron-ipolar-skyguider-pro?rfsn=3263575.8c059d&utm_source=refersion&utm_medium=affiliate&utm_campaign=3263575.8c059d

The author linked to an amazon page which says "full package" in the title, which is now dead. These things usually have different package options listed, which can be selected from.

I see nothing really to indicate that the author selected any particular degraded set-up for this device and used a degraded mode which supports your circular motor idea.

Usually if you're going to buy an advanced package like this, you want to use its full features.

Also, the stars aren't even in the same position on the screen throughout the video.
Title: Re: How does FE explain star trails?
Post by: JSS on February 07, 2021, 10:49:12 PM
The mount in that video is an advanced tracking mount like described would be necessary on the astropix.com site. It isn't merely a motor that goes in a circle. It can be connected to computers, uses cameras for tracking, and has add-ons that track and guide.

https://www.altairastro.com/ioptron-skyguider-pro-camera-mount-full-package-2227-p.asp

"For more advanced users who want extra-long exposures and or have longer focal length lenses, the built-in autoguiding port allows even more accurate tracking with an external guide camera such as the popular Altair GPCAM2 Mono."

There is another device in that package that has a camera as well: https://optcorp.com/products/ioptron-ipolar-skyguider-pro?rfsn=3263575.8c059d&utm_source=refersion&utm_medium=affiliate&utm_campaign=3263575.8c059d

The author linked to an amazon page which says "full package" in the title, which is now dead. These things usually have different package options listed, which can be selected from.

I see nothing really to indicate that the author selected any particular degraded set-up for this device and used a degraded mode which supports your circular motor idea.

Usually if you're going to buy an advanced package like this, you want to use its full features.

Also, the stars aren't even in the same position on the screen throughout the video.

You said...

"I see nothing really to indicate that the author selected any particular degraded set-up"

then...

"the stars aren't even in the same position on the screen throughout the video"

I would suggest that if the stars are visibly shifting through the video, that is actually "something to really indicate" he didn't use the full star-tracking capabilities.  Otherwise there would be no shifting at all.

Tom, you have provided no compelling evidence that these mounts do not work exactly as advertised.  You keep demanding proof, but provide none in return, and have ignored everything I've tried to teach you on the subject.

You could spend $50 on a super cheap equatorial tracking mount and run your own experiments.  Or visit the local astronomy club, I've suggested this before.  You can see these things with your own eyes if you don't trust anyone on the internet.

I do recall this site encourages people to understand and familiarize themselves with the wiki pages of subjects they wish to discuss in detail.
Title: Re: How does FE explain star trails?
Post by: AATW on February 08, 2021, 09:19:11 AM
It doesn't say anything about being accurate for ten hours. Find authoritative third party evidence which says that long-term tracking of the stars with an EQ mount has occured. You have provided nothing at all, except for your insistence that it is possible.
Why are you continuing to argue that the stars don't go in circles when your Wiki, which you wrote, says they do?
Do you just argue with anything anyone says for the sake of it whether it agrees with arguments you've previously made or not? ???

Just Googling things and bolding the parts which you think backs up your view - even if other non-bolded parts completely contradict it - is not an honest way of arguing. And the fact that the initial article you found wasn't even talking about the right kind of mount shows you're not arguing in good faith.

Are you arguing just for the sake of it or do you think the notion that the stars don't move in circles (again, your Wiki says they do) in some ways helps FE? How does it?

Your continued inability to address other issues like the angular size and magnitude of stars being constant despite them being in your model at significantly different distances throughout the night sky is telling.
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on February 10, 2021, 08:41:53 PM
Quote from: JSS
I would suggest that if the stars are visibly shifting through the video, that is actually "something to really indicate" he didn't use the full star-tracking capabilities.  Otherwise there would be no shifting at all.

No, a delay or misfunction could be appropriated to many causes. This suggestion is bunk. If the device can optically track the stars, then we have to assume that it's optically tracking the stars.

Quote from: JSS
Tom, you have provided no compelling evidence that these mounts do not work exactly as advertised.

They are not advertised to track the stars for a long period of time. The EQ mount I posted advertised "up to 5 minutes".

Quote
Why are you continuing to argue that the stars don't go in circles when your Wiki, which you wrote, says they do?

Actually, it doesn't talk about that subject and makes no statements on the POV of the observer.

Quote
Your continued inability to address other issues like the angular size and magnitude of stars being constant despite them being in your model at significantly different distances throughout the night sky is telling.

It's pretty telling that you are unaware that the size of the stars are illusions in RE, and do not follow the angular size with distance rule of perspective - https://wiki.tfes.org/Star_Size_Illusion
Title: Re: How does FE explain star trails?
Post by: JSS on February 10, 2021, 09:48:16 PM
Quote from: JSS
I would suggest that if the stars are visibly shifting through the video, that is actually "something to really indicate" he didn't use the full star-tracking capabilities.  Otherwise there would be no shifting at all.

No, a delay or misfunction could be appropriated to many causes. This suggestion is bunk. If the device can optically track the stars, then we have to assume that it's optically tracking the stars.

Your suggestion is bunk, you are now claiming that if a device CAN perform a function it MUST perform the function... even if the video clearly shows it is not. The optical tracker can be turned off or even removed, this is a fact.

That is very bad logic.

Quote from: JSS
Tom, you have provided no compelling evidence that these mounts do not work exactly as advertised.

They are not advertised to track the stars for a long period of time. The EQ mount I posted advertised "up to 5 minutes".

Here you are making up an unreasonable demand, that an EQ mount must be able to track stars with 100% perfect accuracy for 10 hours, then saying because they can't meet this made-up demand of yours, that they can't track stars at all.

This is another case of very bad logic.

You have made up your own definition of 'long time' that is based on your ignorance of what the astrophotography community's standards agree on. Five minutes on a 200mm telephoto IS a long time.

EQ mounts can track stars all night, they just drift due to mechanical errors.  I have tried to explain the precision required but you seem to have not read it and just called it 'rambling'.  GO back and read my post again, it explains the difficulties of aligning something perfectly with the axis of the earth to match it's rotation to the point a sub-micron pixel stays stable.  I'm sorry you don't seem to understand precision and the limits of physical systems.

Googling random message boards and copy-pasting bits of conversation that you do not have the context to understand is not a good argument.
Title: Re: How does FE explain star trails?
Post by: SteelyBob on February 10, 2021, 10:32:41 PM
Quote from: JSS
I would suggest that if the stars are visibly shifting through the video, that is actually "something to really indicate" he didn't use the full star-tracking capabilities.  Otherwise there would be no shifting at all.

No, a delay or misfunction could be appropriated to many causes. This suggestion is bunk. If the device can optically track the stars, then we have to assume that it's optically tracking the stars.

Quote from: JSS
Tom, you have provided no compelling evidence that these mounts do not work exactly as advertised.

They are not advertised to track the stars for a long period of time. The EQ mount I posted advertised "up to 5 minutes".

Quote
Why are you continuing to argue that the stars don't go in circles when your Wiki, which you wrote, says they do?

Actually, it doesn't talk about that subject and makes no statements on the POV of the observer.

Quote
Your continued inability to address other issues like the angular size and magnitude of stars being constant despite them being in your model at significantly different distances throughout the night sky is telling.

It's pretty telling that you are unaware that the size of the stars are illusions in RE, and do not follow the angular size with distance rule of perspective - https://wiki.tfes.org/Star_Size_Illusion

I note you're completely ignoring my post above where I showed a projected 10-hour tracking error of just over 1 degree for a decent EQ mount.

You seem to have completely failed to grasp the distinction between taking a good photo of a star (hence 5 minutes and other low numbers) and tracking a star adequately enough to be able to find it - the two things are very different. Likewise, the concept of periodic and cumulative errors is also passing right over you.

If the stars were moving in the kind of ellipses that your youtube fantasists were illustrating in their video, then we would be seeing way, way bigger errors than the numbers shown in those graphs. The fact that we don't is telling.

As for accusing that other video of employing star tracking - that's just laughably ridiculous, and completely missing the point. The thing to take away from that video is that the entire celestial picture is moving as one undistorted body - there's no visible change at all in the relationship between the stars. It's so far away from what your modelling videos it's ridiculous. And you can observe that yourself on any clear night.

To be honest, I'm just trying to work out if you actually, genuinely don't understand this, or if you're just engaged in some kind of wind-up. Either way...odd.
Title: Re: How does FE explain star trails?
Post by: JSS on February 10, 2021, 11:43:22 PM
As for accusing that other video of employing star tracking - that's just laughably ridiculous, and completely missing the point. The thing to take away from that video is that the entire celestial picture is moving as one undistorted body - there's no visible change at all in the relationship between the stars. It's so far away from what your modelling videos it's ridiculous. And you can observe that yourself on any clear night.

I'm going to have to make a video like this once I get some good weather and can sit outside for several hours.  You're right, it's a perfect example of how the stars move completely together, no ovals possible since the stars are motionless and rotating all at once.
Title: Re: How does FE explain star trails?
Post by: AATW on February 11, 2021, 10:29:05 AM
It's pretty telling that you are unaware that the size of the stars are illusions in RE, and do not follow the angular size with distance rule of perspective - https://wiki.tfes.org/Star_Size_Illusion

I like the fact that you quote part of an article on that page which includes this sentence:

Quote
Today, despite the advances in technology and knowledge, science faces rejection by those who claim that it is bedeviled by hoaxes, conspiracies, or suppressions of data by powerful establishments.

Sound familiar? :)

I'm also amused that you think that perspective is something which is optional and only some objects obey, as though perspective is a subscription service which not every object is signed up to. For ages on here you were arguing that sunset happens by "perspective", more recently you seem to have jumped on the EA bandwagon and now argue that the sun and moon randomly don't obey perspective. Yes, they're at vastly varying distances during the day/night but they maintain a constant angular size through the night because of some effect which I showed some time ago is debunked by the images on your Wiki page about it. And the effect is claimed to work for bright lights so wouldn't apply to the crescent moon.

There is some optical effect because stars are so distant they are effectively point sources, but in your model they aren't that distant. So why wouldn't they greatly vary in angular size?

And why are you arguing against the stars moving in circles when the Wiki page which you wrote claims they do? ???
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on February 11, 2021, 08:03:14 PM
I note you're completely ignoring my post above where I showed a projected 10-hour tracking error of just over 1 degree for a decent EQ mount.

This isn't sufficient evidence. If you set up EQ mount and set up and align the various components which attach to the telescope and mount, a captured star in view will drift out of frame, either quickly or more slowly, but drift out of frame none-the-less, and in minutes. Assuming that the person recorded his best time for his website and you have then extrapolated that sample time out to 10 hours, it still doesn't show that the telescope's view was traveling in a perfect circle with the EQ mount. The alignment of the components on the device or alignment with the pole could still be off, and the trial could only be matching the particular elliptical or oblong shape of the star's path to get the "best" case for the sample. So really, this approach means nothing on its own to show the shape of the star paths, and mainly verifies that the EQ mount cannot track the stars for very long in contradiction to the previous statements here.
Title: Re: How does FE explain star trails?
Post by: JSS on February 12, 2021, 12:16:20 AM
I note you're completely ignoring my post above where I showed a projected 10-hour tracking error of just over 1 degree for a decent EQ mount.

This isn't sufficient evidence. If you set up EQ mount and set up and align the various components which attach to the telescope and mount, a captured star in view will drift out of frame, either quickly or more slowly, but drift out of frame none-the-less, and in minutes.

Wrong.

This is completely and totally incorrect and anyone who has used an EQ mount will tell you so. You really need to research subjects better before making such statements.

I can use the same camera and lens I used to make my earlier star trails photo, put it on my equatorial mount and keep any star I choose in the frame for your ten hours if I wanted.

You still think that people saying you can only have a shutter time of 5 minutes means the star drifts out of frame that fast, this is completely wrong and in total ignorance of the basics of astrophotography. In 5 minutes it will drift a tiny amount, enough to move a few pixels on the camera sensor and cause the star to blur.  But it's hardly going to move out of the frame, and will remain closely centered for hours if carefully lined up first.

Assuming that the person recorded his best time for his website and you have then extrapolated that sample time out to 10 hours, it still doesn't show that the telescope's view was traveling in a perfect circle with the EQ mount. The alignment of the components on the device or alignment with the pole could still be off, and the trial could only be matching the particular elliptical or oblong shape of the star's path to get the "best" case for the sample. So really, this approach means nothing on its own to show the shape of the star paths, and mainly verifies that the EQ mount cannot track the stars for very long in contradiction to the previous statements here.

Stars do not move in ellipses, your own wiki says so, and photographic evidence says so.  Look at the video again, the camera is rotating but the stars all stay put, only driving TOGETHER as the camera moves slightly out of alignment.  If they were moving in ellipses you would see some stars moving out of sync with the other and NO video with a rotating camera shows that.

You simply do not understand what "can only track for 5 minutes" means.  YOu should post on some of these star forums and ask for clarification if you are confused over what they are actually saying, they will happily explain it to you.
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on February 12, 2021, 12:32:25 AM
You still think that people saying you can only have a shutter time of 5 minutes means the star drifts out of frame that fast, this is completely wrong and in total ignorance of the basics of astrophotography. In 5 minutes it will drift a tiny amount, enough to move a few pixels on the camera sensor and cause the star to blur.

Nope.

The author in the link we are discussing shows that the star drifts out of shot within a short amount of time.

http://www.pk3.org/Astro/index.htm?astrophoto_mount_errors.htm

"Capture Selected Frames capture mode was selected with period 1 second (exact period was 1.11s)."

(https://i.ibb.co/TccG5B1/vega-track-error.gif)

Meanwhile you continue to provide zero evidence or reference that it is possible to keep it lined up for hours, and merely repeat this statement without qualification, in contradiction to multiple references which suggest that it only stays in frame for a short amount of time.
Title: Re: How does FE explain star trails?
Post by: JSS on February 12, 2021, 12:51:20 AM
You still think that people saying you can only have a shutter time of 5 minutes means the star drifts out of frame that fast, this is completely wrong and in total ignorance of the basics of astrophotography. In 5 minutes it will drift a tiny amount, enough to move a few pixels on the camera sensor and cause the star to blur.

Nope.

The author in the link we are discussing shows that the star drifts out of shot within a short amount of time.

http://www.pk3.org/Astro/index.htm?astrophoto_mount_errors.htm

"Capture Selected Frames capture mode was selected with period 1 second (exact period was 1.11s)."

(https://i.ibb.co/TccG5B1/vega-track-error.gif)

Meanwhile you continue to provide zero evidence or reference that it is possible to keep it lined up for hours, and merely repeat this statement without qualification.

Tom, did you read the part where I mentioned I could get ten hours using the same lens I did with my first star trails shot?

Lenses and scopes matter a LOT in how long a shot stays in the frame.  His example is using a high magnification telescope that increases the error that occurred over 24 minutes and 35 seconds. You using that example shows you really don't understand what's going on here.  If I used my camera instead that star would have remained very closely centered.

Lets repeat that, the star moved a small amount across his highly magnified view in 23 minutes.  That's not going entirely out of the frame in 5 minutes like you claim.

You need to understand how lenses and magnification works before you tell people things they literally do are impossible. You misunderstanding things is not evidence.

The video presented earlier still trumps any other argument, it shows the entire field of stars moving as one. Not ellipses, not ovals, all rotating around a single point. In circles.

Title: Re: How does FE explain star trails?
Post by: Tom Bishop on February 12, 2021, 12:54:26 AM
You have no authoritative evidence for this claim that it is possible to keep a star in frame of a telescope or otherwise without star trails on a EQ telescope mount for hours at a time. Every time you are asked for appropriate sources you continue to merely insist that you "know" that it's right. Please refrain from spreading claims without supporting evidence from appropriate sources, kindly.

Title: Re: How does FE explain star trails?
Post by: Tom Bishop on February 12, 2021, 01:15:18 AM
Previously you told us that we could just buy one of these telescopes and that it will keep the star "perfectly aligned." Now you're changing your tune and saying that we need to get rid of the telescope use and only use a camera mounted on an EQ mount.

I have been thinking about how to prove stars move in perfect circles, no matter where you are on the planet and I think I have a simple, direct method to do so.

The Equatorial Telescope Mount

(https://www.spaceoddities.eu/wp-content/uploads/2018/08/equatorial-mount.jpg)

This is a very simple device, it's just shaft with a motor that turns the telescope in a circle, making one rotation every 24 hours.

When you point the axis of this motor at the north or south pole star, you can then mount your telescope to it, aim your telescope at a star and that star will remain perfectly centered in your viewfinder as the telescope is now rotating with the stars.

The key here is this mount simply rotates your telescope in a circle. That is all it does. It is physically a single axis, it's incapable of moving in anything BUT a circle. It literally can not turn in ovals or parabolas or any other shape, it is a single rotating axis. And it will keep any star you look at perfectly aligned.

This could not be possible if the stars did not also move in perfect circles.

There are hundreds of sites explaining how EQ mounts work and how to set them up if anyone wants to look them up. The EQ mount has been made and sold to millions of people around the world, it's widely used and so simple there can be little confusion on how it operates, and if it did not work as advertised, this would be well known by now.

You apparently do not know how it operates, because we can't just buy a telescope and expect the stars in view to stay perfectly aligned with a EQ mount for very long.

Now you are conceding to this and ranting about how we need to use an EQ mount and a camera, backtracking away from the telescopes that you told us about.
Title: Re: How does FE explain star trails?
Post by: stack on February 12, 2021, 01:37:46 AM
You have no authoritative evidence for this claim that it is possible to keep a star in frame of a telescope or otherwise without star trails on a EQ telescope mount for hours at a time. Every time you are asked for appropriate sources you continue to merely insist that you "know" that it's right. Please refrain from spreading claims without supporting evidence from appropriate sources, kindly.

Here's a neat Dusk-to-Dawn (At least 8 hours) time-lapse keeping stars in frame without trails. That would constitute "hours at a time", right? What's all this business that you can only track stars for minutes?

(https://i.imgur.com/3G2RC7S.gif)
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on February 12, 2021, 01:59:19 AM
You have no authoritative evidence for this claim that it is possible to keep a star in frame of a telescope or otherwise without star trails on a EQ telescope mount for hours at a time. Every time you are asked for appropriate sources you continue to merely insist that you "know" that it's right. Please refrain from spreading claims without supporting evidence from appropriate sources, kindly.

Here's a neat Dusk-to-Dawn (At least 8 hours) time-lapse keeping stars in frame without trails. That would constitute "hours at a time", right? What's all this business that you can only track stars for minutes?

https://i.imgur.com/3G2RC7S.gif

Nope. JSS has been repeatedly arguing about keeping stars in telescopes:

You are clearly able to use Google, so I'm confused how you are unable to look up the ability of equatorial mount telescopes to track stars.

But if you would like me to do it for you I ask again, and please answer this time, what do you mean by proving they can track for a 'long' time?  And why do you need to track them all night?  An hour is plenty of time to get a good star trail picture.

You seem to be suggesting that if a telescope can 'only' track for 10 hours and not 10 hours and 1 second, then it can't track the stars at all?

You keep asking me to prove telescopes can track stars, but continue to refuse to narrow down your request so I can do so.

1. How many hours do you need for proof?

2. What amount of magnification?

Now his argument isn't about telescopes anymore because he realized that he was incorrect.

After arguing about telescopes at length on this matter he concedes and admits that he is wrong and wants to avoid use of a telescope altogether.
Title: Re: How does FE explain star trails?
Post by: stack on February 12, 2021, 02:02:42 AM
You have no authoritative evidence for this claim that it is possible to keep a star in frame of a telescope or otherwise without star trails on a EQ telescope mount for hours at a time. Every time you are asked for appropriate sources you continue to merely insist that you "know" that it's right. Please refrain from spreading claims without supporting evidence from appropriate sources, kindly.

Here's a neat Dusk-to-Dawn (At least 8 hours) time-lapse keeping stars in frame without trails. That would constitute "hours at a time", right? What's all this business that you can only track stars for minutes?

https://i.imgur.com/3G2RC7S.gif

Nope. JSS has been repeatedly arguing about keeping stars in telescopes:

You are clearly able to use Google, so I'm confused how you are unable to look up the ability of equatorial mount telescopes to track stars.

But if you would like me to do it for you I ask again, and please answer this time, what do you mean by proving they can track for a 'long' time?  And why do you need to track them all night?  An hour is plenty of time to get a good star trail picture.

You seem to be suggesting that if a telescope can 'only' track for 10 hours and not 10 hours and 1 second, then it can't track the stars at all?

You keep asking me to prove telescopes can track stars, but continue to refuse to narrow down your request so I can do so.

1. How many hours do you need for proof?

2. What amount of magnification?

My scope can certainly track stars all night long if I have a wide angle lens.  Less if I start to zoom in.

Now suddenly his argument isn't about telescopes anymore because he realized that he was incorrect.

After arguing about telescopes at length on this matter he concedes and admits that he is wrong and wants to avoid use of a telescope altogether.

What in the world are you going on about? You're saying you can't track stars for more than a few minutes, yet you've been told and shown that you can track stars for hours. Do you get that yet?

What's this about "he...wants to avoid use of a telescope altogether."? Where is that coming from? Aren't we talking about telescopes with EQ mounts, tripods, stars, tracking, etc.? I have no idea what you're even saying anymore, you're so all over the place.
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on February 12, 2021, 02:09:04 AM
You have no authoritative evidence for this claim that it is possible to keep a star in frame of a telescope or otherwise without star trails on a EQ telescope mount for hours at a time. Every time you are asked for appropriate sources you continue to merely insist that you "know" that it's right. Please refrain from spreading claims without supporting evidence from appropriate sources, kindly.

Here's a neat Dusk-to-Dawn (At least 8 hours) time-lapse keeping stars in frame without trails. That would constitaute "hours at a time", right? What's all this business that you can only track stars for minutes?

https://i.imgur.com/3G2RC7S.gif

Nope. JSS has been repeatedly arguing about keeping stars in telescopes:

You are clearly able to use Google, so I'm confused how you are unable to look up the ability of equatorial mount telescopes to track stars.

But if you would like me to do it for you I ask again, and please answer this time, what do you mean by proving they can track for a 'long' time?  And why do you need to track them all night?  An hour is plenty of time to get a good star trail picture.

You seem to be suggesting that if a telescope can 'only' track for 10 hours and not 10 hours and 1 second, then it can't track the stars at all?

You keep asking me to prove telescopes can track stars, but continue to refuse to narrow down your request so I can do so.

1. How many hours do you need for proof?

2. What amount of magnification?

My scope can certainly track stars all night long if I have a wide angle lens.  Less if I start to zoom in.

Now suddenly his argument isn't about telescopes anymore because he realized that he was incorrect.

After arguing about telescopes at length on this matter he concedes and admits that he is wrong and wants to avoid use of a telescope altogether.

What in the world are you going on about? You're saying you can't track stars for more than a few minutes, yet you've been told and shown that you can track stars for hours. Do you get that yet?

What's this about "he...wants to avoid use of a telescope altogether."? Where is that coming from? Aren't we talking about telescopes with EQ mounts, tripods, stars, tracking, etc.? I have no idea what you're even saying anymore, you're so all over the place.

Follow the thread please. The argument was about tracking in telescopes:

You are confused that some users get better tracking with a telescope mount DESIGNED FOR BETTER TRACKING rather than a telescope designed to be cheap? Why is this a point of confusion for you?  If you want long term tracking, buy a mount designed for that.

Now you want to go down the rabbit hole of proving to you that telescopes can track stars for a 'long' duration.  Fine, but please specify what 'long' is so I don't waste my time, thanks.

The topic was tracking in telescopes. Now you guys want to change this topic because you understand that you are wrong.
Title: Re: How does FE explain star trails?
Post by: JSS on February 12, 2021, 02:11:41 AM
Previously you told us that we could just buy one of these telescopes and that it will keep the star "perfectly aligned." Now you're changing your tune and saying that we need to get rid of the telescope use and only use a camera mounted on an EQ mount.

You apparently do not know how it operates, because we can't just buy a telescope and expect the stars in view to stay perfectly aligned with a EQ mount for very long.

Now you are conceding to this and ranting about how we need to use an EQ mount and a camera, backtracking away from the telescopes that you told us about.

Tom, do you understand that a camera attached to a telescope and a camera attached to a lens is the same thing? Both are lenses, we just call one a telescope. You can attache either to a mount, and many people do. If you are confused, please feel free to go to any astronomy forum and ask your questions.  I'm sure they would help you, and they will back up what I am saying.

While you're there ask them if stars go in circles or ovals. ::)

You can claim out of ignorance that telescopes that are designed to track stars can't track stars, but millions of people who use them prove you wrong.

I can keep the stars in frame with my 20mm prime lens, and will do so if I ever get a nice clear warm night. Ask anyone who owns a telescope and an eq mount and they will give you the same answer I am.
Title: Re: How does FE explain star trails?
Post by: stack on February 12, 2021, 02:14:07 AM
You have no authoritative evidence for this claim that it is possible to keep a star in frame of a telescope or otherwise without star trails on a EQ telescope mount for hours at a time. Every time you are asked for appropriate sources you continue to merely insist that you "know" that it's right. Please refrain from spreading claims without supporting evidence from appropriate sources, kindly.

Here's a neat Dusk-to-Dawn (At least 8 hours) time-lapse keeping stars in frame without trails. That would constitaute "hours at a time", right? What's all this business that you can only track stars for minutes?

https://i.imgur.com/3G2RC7S.gif

Nope. JSS has been repeatedly arguing about keeping stars in telescopes:

You are clearly able to use Google, so I'm confused how you are unable to look up the ability of equatorial mount telescopes to track stars.

But if you would like me to do it for you I ask again, and please answer this time, what do you mean by proving they can track for a 'long' time?  And why do you need to track them all night?  An hour is plenty of time to get a good star trail picture.

You seem to be suggesting that if a telescope can 'only' track for 10 hours and not 10 hours and 1 second, then it can't track the stars at all?

You keep asking me to prove telescopes can track stars, but continue to refuse to narrow down your request so I can do so.

1. How many hours do you need for proof?

2. What amount of magnification?

My scope can certainly track stars all night long if I have a wide angle lens.  Less if I start to zoom in.

Now suddenly his argument isn't about telescopes anymore because he realized that he was incorrect.

After arguing about telescopes at length on this matter he concedes and admits that he is wrong and wants to avoid use of a telescope altogether.

What in the world are you going on about? You're saying you can't track stars for more than a few minutes, yet you've been told and shown that you can track stars for hours. Do you get that yet?

What's this about "he...wants to avoid use of a telescope altogether."? Where is that coming from? Aren't we talking about telescopes with EQ mounts, tripods, stars, tracking, etc.? I have no idea what you're even saying anymore, you're so all over the place.

Follow the thread please. The argument was about tracking in telescopes:

You are confused that some users get better tracking with a telescope mount DESIGNED FOR BETTER TRACKING rather than a telescope designed to be cheap? Why is this a point of confusion for you?  If you want long term tracking, buy a mount designed for that.

Now you want to go down the rabbit hole of proving to you that telescopes can track stars for a 'long' duration.  Fine, but please specify what 'long' is so I don't waste my time, thanks.

The topic was tracking in telescopes. Now you guys want to change this topic because you understand that you are wrong.

Change the topic to what? Everyone is talking about telescopes, cameras, lenses, EQ mounts, tripods, stars, tracking, etc. All the stuff used to do astrophotography. How do you do your astrophotography? With a disposable camera from Wallgreens?
Title: Re: How does FE explain star trails?
Post by: JSS on February 12, 2021, 02:18:28 AM
The topic was tracking in telescopes. Now you guys want to change this topic because you understand that you are wrong.

The topic was actually FE explaining star trails, which you have yet to provide any answer for and are reduced to claiming stars don't go in circles even though the wiki that you wrote says they do.

I've provided plenty of examples to prove you wrong. 

Here is another showing that the entire sky of stars is static, done by recording 24 hours and rotating the video to show how the stars are fixed.  If the stars are going in ovals then how come they are not moving in relation to others?  This video and all the others completely invalidates all your claims.

https://www.youtube.com/watch?v=SYcKaBzr87g


Title: Re: How does FE explain star trails?
Post by: scomato on February 12, 2021, 02:23:27 AM
it is possible to keep a star in frame of a telescope or otherwise without star trails on a EQ telescope mount for hours at a time.

Tom, there are many How-To guides on YouTube for doing this, using a device such as a Sky-Watcher Star Adventurer Motorized Mount. It is the basis of astrophotography, a hobby that many non-scientists enjoy.

This is a great video of a guy doing this in his backyard, with top tier hardware. He is keeping Mars in frame, without trailing, for hours at a time. At 7:26 in this video, you can see a tracked preview image of Mars without any trailing, and his final photo is not smeared like a time lapse.

https://www.youtube.com/watch?v=veVN3e2n_r8
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on February 12, 2021, 02:30:30 AM
Quote from: stack
Change the topic to what? Everyone is talking about telescopes, cameras, lenses, EQ mounts, tripods, stars, tracking, etc. All the stuff used to do astrophotography. How do you do your astrophotography? With a disposable camera from Wallgreens?

The discussion was clearly tracking with telescopes. I can see with your reply that you choose to be disingenuous to this and see no further point in discussion.

The topic was actually

You were talking about telescope tracking in those quotes about the EQ mount and have failed to maintain your position.

Quote
Here is another showing that the entire sky of stars is static, done by recording 24 hours and rotating the video to show how the stars are fixed.  If the stars are going in ovals then how come they are not moving in relation to others?  This video and all the others completely invalidates all your claims.

https://www.youtube.com/watch?v=SYcKaBzr87g (https://www.youtube.com/watch?v=SYcKaBzr87g)

Incorrect. The stars are drifting in the video there. They don't stay in the same spot on the screen. It's also easily edited/rescaled to get the ideal result like the previous images. It doesn't matter that it's a video. By your previous standards, if it's possible for the media to have been edited then it's invalid.

it is possible to keep a star in frame of a telescope or otherwise without star trails on a EQ telescope mount for hours at a time.

Tom, there are many How-To guides on YouTube for doing this, using a device such as a Sky-Watcher Star Adventurer Motorized Mount. It is the basis of astrophotography, a hobby that many non-scientists enjoy.

This is a great video of a guy doing this in his backyard, with top tier hardware. He is keeping Mars in frame, without trailing, for hours at a time. At 7:26 in this video, you can see a tracked preview image of Mars without any trailing, and his final photo is not smeared like a time lapse.

https://www.youtube.com/watch?v=veVN3e2n_r8

Go to 2:24: "The guide telescope on top is..." and "I have a small asi 120mm mini guide camera in there..."

There is a guiding device on the telescope that optically tracks the celestial bodies to move the telescope in tandem:

(https://i.imgur.com/JYin7M1.png)
Title: Re: How does FE explain star trails?
Post by: stack on February 12, 2021, 05:25:01 AM
Quote from: stack
Change the topic to what? Everyone is talking about telescopes, cameras, lenses, EQ mounts, tripods, stars, tracking, etc. All the stuff used to do astrophotography. How do you do your astrophotography? With a disposable camera from Wallgreens?

The discussion was clearly tracking with telescopes. I can see with your reply that you choose to be disingenuous to this and see no further point in discussion.

The topic is "How does FE explain star trails?" Within that topic, the discussion has been about tracking with telescopes. And it still is. I don't know why you think it isn't?

Astrophotography = taking photographs of astronomical objects, hence the name (Astro+Photo). To do that, you need a sky, astronomical objects, camera with some type of lens, like a telescope or perhaps a really long camera lens. If you want to track astronomical objects it helps greatly to have a tripod for stabilization, and even better, the addition of an EQ mount. And there you have it: Gear to track and image astronomical objects. What are you confused about?

Go to 2:24: "The guide telescope on top is..." and "I have a small asi 120mm mini guide camera in there..."

There is a guiding device on the telescope that optically tracks the celestial bodies to move the telescope in tandem:

(https://i.imgur.com/JYin7M1.png)

So what? "During the length of the exposure, the astro-imager follows the motion of a star—the guide star—and, when the star appears to move slightly because of errant motion of the mount, applies a corrective signal to the mount to move the star back to its original position."

Just another arrow in the astrophotographer's quiver to help with tracking, especially at the amateur gear/proficiency level.
Title: Re: How does FE explain star trails?
Post by: JSS on February 12, 2021, 02:08:26 PM
For anyone confused about the difference between cameras and lenses and telescopes here is some quick information about equipment I own.

This is just a cheap (but great build quality) 500mm focal length telescope.  It's got a mount for a DSLR camera on the side.

(https://i.imgur.com/CQw04AE.jpg)

This is also a 500mm focal length telescope, it has the same camera mount on the back end as the bigger telescope. It mounts directly to the camera. This looks like a normal lens so it's easier to recognize the similarities.

(https://i.imgur.com/5r8ELWo.jpg)

Do you see why being confused over using a lens vs using a telescope is silly? In either case you are hooking a camera up to some glass and a tube.

Hopefully this clears things up so nobody is confused over why we are talking about both camera lenses and telescopes in the same discussion, they are functionally equivalent.
Title: Re: How does FE explain star trails?
Post by: SteelyBob on February 12, 2021, 09:41:17 PM
it's possible for the media to have been edited it's invalid.

And that's it, right there, in a nutshell, isn't it? Despite thousands of people the whole world over participating in this hobby, despite an overwhelming preponderance of high quality evidence, it might be faked. Kind of true, really - it could be. Everything can be faked. That stunning video that JSS posted (thanks JSS - never seen that before. Amazing) Every video, every instruction manual, every website. Every design for a telescope mount, every patent, every moon landing video, every how-to-adjust-the-drift-nut-on-your-directional-gyro, it all could be faked. My plea - and this is directed at other people reading this, because you're either being deliberately disingenuous  or are truly beyond hope - is to ask yourself, which is more likely? The mass fakery, or the scientific consensus?
Title: Re: How does FE explain star trails?
Post by: Tom Bishop on February 12, 2021, 09:49:54 PM
Quote
For anyone confused about the difference between cameras and lenses and telescopes here is some quick information about equipment I own.

It appears that you are the one who is confused between a telescope and a camera. From your previous quotes you were arguing about the view through telescopes on EQ mounts and are now abandoning that argument and insist that the EQ mount discussion is not about telescopes anymore, and that you only mean the view through a camera only.

it's possible for the media to have been edited it's invalid.

And that's it, right there, in a nutshell, isn't it? Despite thousands of people the whole world over participating in this hobby, despite an overwhelming preponderance of high quality evidence, it might be faked. Kind of true, really - it could be. Everything can be faked. That stunning video that JSS posted (thanks JSS - never seen that before. Amazing) Every video, every instruction manual, every website. Every design for a telescope mount, every patent, every moon landing video, every how-to-adjust-the-drift-nut-on-your-directional-gyro, it all could be faked. My plea - and this is directed at other people reading this, because you're either being deliberately disingenuous  or are truly beyond hope - is to ask yourself, which is more likely? The mass fakery, or the scientific consensus?

Previously in this thread multiple images were rejected because it was possible that they were modified. Now you want to bring in a piece of media and insist that it is not modified, when it is possible that it was modified by the authors to get an ideal result for their purposes. This is hypocrisy, regardless of the validity of the media. If it is possible that it was modified then it must be discarded by those same standards.
Title: Re: How does FE explain star trails?
Post by: SteelyBob on February 12, 2021, 09:55:06 PM
it's possible for the media to have been edited it's invalid.

And that's it, right there, in a nutshell, isn't it? Despite thousands of people the whole world over participating in this hobby, despite an overwhelming preponderance of high quality evidence, it might be faked. Kind of true, really - it could be. Everything can be faked. That stunning video that JSS posted (thanks JSS - never seen that before. Amazing) Every video, every instruction manual, every website. Every design for a telescope mount, every patent, every moon landing video, every how-to-adjust-the-drift-nut-on-your-directional-gyro, it all could be faked. My plea - and this is directed at other people reading this, because you're either being deliberately disingenuous  or are truly beyond hope - is to ask yourself, which is more likely? The mass fakery, or the scientific consensus?

Previously in this thread multiple images were rejected because it was possible that they were modified. Now you want to bring in a piece of media and insist that it is not modified, when it is possible that it was modified by the authors to get an ideal result for their purposes. This is hypocrisy, regardless of the validity of the media. If it is possible that it was modified then it must be discarded by those same standards.

Can you give me an example of a piece of video or image media that could not have been faked?
Title: Re: How does FE explain star trails?
Post by: JSS on February 13, 2021, 01:55:04 AM
Quote
For anyone confused about the difference between cameras and lenses and telescopes here is some quick information about equipment I own.

It appears that you are the one who is confused between a telescope and a camera. From your previous quotes you were arguing about the view through telescopes on EQ mounts and are now abandoning that argument and insist that the EQ mount discussion is not about telescopes anymore, and that you only mean the view through a camera only.

Did you not read my post? ::)

I tried, using simple pictures and being as brief as possible (as you complain when explanations are too lengthy or complex) to show you that there is no difference between hooking up a camera to a telescope to look at stars, and hooking up a lens to a camera to look at stars.

They are the same thing, a tube with glass in it. 

I am at a loss as how you are unable to comprehend this.  What is confusing you?

You need to look beyond the words, Tom. Camera, telescope, lens... yes these are different words but I am talking about the exact same thing with all of them. Attaching them to an EQ mount to track and photograph the stars.

Again... a telescope and a zoom lens perform the SAME FUNCTION.  You look through them and they magnify and focus light. 

I think you need to spend some time learning about hos all this works.  You really should make some accounts on various astronomy forums and ask questions there.  Your claim that stars go in ovals goes against everything millions of people observe with their own telescopes and yes, cameras.  It's very simply to explain that a device designed to turn in circles is meant to track things that also move in circles.  Go to some other forums and ask your questions to verify what I am saying.  You will find they give the same answers I do.  Ask if stars go in ovals or circles.  Ask if EQ mounts are meant to go in circles and track circular stars.

You don't have to limit yourself, there is a whole world out there of people who have the answers to your questions.  Ask them.  Do some research, the truth is out there.
Title: Re: How does FE explain star trails?
Post by: AATW on February 13, 2021, 09:58:45 AM
Your claim that stars go in ovals goes against everything millions of people observe with their own telescopes and yes, cameras.
More to the point, it goes against a Wiki page on here which Tom wrote.
Which leads me to believe Tom is arguing in bad faith here and just arguing for the sake of arguing.
And I don’t see how this is a point for FE either way.

The original topic was how FE explains star trails. The way the stars circle around Polaris in the North, circle around a southern point in the south in the opposite direction and the trail picture I posted from the equator is explained - indeed predicted - by a model of us living on a rotating globe with distant stars. That model also explains the constant magnitude of stars and the constant positions in relation to each other.

FE can only explain this by inventing ad hoc mechanisms or just flat out denial.

Tom’s attempt to derail this thread and his unwillingness to make any observations himself shows the weakness of his position.