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Messages - astroman

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Flat Earth Theory / Re: Found a fully working flat earth model?
« on: March 04, 2022, 09:14:45 PM »
If you have found a fully working flat Earth model then why are you just talking about in these forums??  You should be getting in touch with Nature magazine cos it will be a truly revolutionary Earth model.  How come no one else has come up with it after all this time? Have you got access to resources, equipment and budgets that no one else has?

It is exactly the sort of thing that Nature magazine is all about. At least it is if it really does work as well as well as you claim it does.

Flat Earth Community / Re: Flat Earth maps?
« on: March 04, 2022, 05:15:52 PM »
Why are you asking for a source when I gave it, and you cut it out of your quote? Dishonest.
Who needs 'sources' in the form of descriptions of how big they imagined the stars to be during the 17th century when you can simply go out and have a look for yourself? In any case Tom your 'sources' are always just links to a page of your FE Wiki. Hardly what can be described as 'independent'. Just go outside, look through a telescope at any star and then look at Jupiter or Saturn even.  See the difference?  You can see the disk of Jupiter with a simple pair of binoculars but Sirius will only ever appear as a point source. Surprise surprise!

It is completely ludicrous to even suggest that Sirius is ever going to look much bigger in an eyepiece than the largest planet in the solar system.  Don't you think? I don't know what telescopes they were using back in the 17th century but if that's the impression that Kepler got then there was something seriously wrong going on.

If you can see Sirius looking like a disk 3x the size of Jupiter through your telescope Tom then either it doesn't work, you are looking through the wrong end (only kidding) or it is seriously out of focus. A star out of focus is going to look like a big disk. I don't know about you but I always find telescopes perform better when they are in focus.

Yeah, claiming that the sizes of the stars are optical illusions definitely supports the narrative that the sizes of the stars and celestial bodies are not optical illusions.
I never said anything about optical illusions did I.  I said the Airy disk is an optical effect of how telescopes work.  Lenses and mirrors are round and the focal plane forms a small circle.  That is the Airy disk. Nothing to do with optical illusions.

You can do so, but it is not considered scientific knowledge. The US Supreme Court (1993) in Daubert v. Merrell made a determination of what qualifies as "scientific knowledge":

Good for them...I don't particularly give a damn what the US supreme court says about scientific knowledge. I tend to go with scientific organisations rather than the law courts to decide on a  definition about what is or what isn't scientific knowledge. Count up how many times the word 'observation' crops up in this source about what scientific knowledge is. Is the US Supreme Court a recognised scientific organisation? Scientific knowledge is gained from the data that we gather. How can we do that completely if we don't count the observations that we make of how nature works? Even when carrying out experiments we learn by observing the results of those experiments.

or indeed this one.. this one even mentions about ancient beliefs about the world being flat!

We know the distance to Sirius and anyone with an ounce of common sense will realise that you are never going to see any physical disk on something that far away with any telescope. The reason being the visible disk diameter is much, much less than the resolving power of any telescope. Hence we see them as point sources.

You may not accept modern methods of measuring the distances to the stars because they don't fall in line with what you want to believe, but that in itself doesn't make them any less valid. Mother nature decides what is true and what isn't, not you. 

With regards to Keplers 'De Stella Nova' publication, I have downloaded the publication but I cannot find any reference to where he apparently addressed the size of the nova. As suggested by the Wiki article...

In On the New Star, Kepler addressed the size of the nova
He did describe the position of the nova relative to nearby stars (with excellent accuracy) and the brightness curve but not the 'size'. He also described how he imagined that all other stars to be giants.  But it doesn't mention the size of the nova specifically. Perhaps you could provide a page number where he addresses that?   Many people seem to describe brightness in terms of size. For example I have heard people say 'I saw Venus last night and it looked really big'. But of course what they mean is it looked really bright. 

Obviously knowledge of the stars in general back in the early 17th century was not quite on a par with what it is today. Thanks largely to developments in spectroscopy and optics during the mid-19th century. You cannot really base your understanding of the stars now with what was known about them during the 17th century.  Except perhaps if it helps your position on what you believe.

Flat Earth Community / Re: Flat Earth maps?
« on: March 04, 2022, 05:01:52 PM »
Even under those claims, the spacecraft are still just observing, and not experimenting, on the stars to know their true nature.
Oh I see, so just because we can't go sample collecting among the stars to bring back to Earth for experimenting on, that means we haven't a clue about the nature of the stars. Right Tom? I can probably learn more about the stars from my back garden using my own spectroscope than you will ever know.

Obviously your definition of the scientific method does not include observation as a means of collecting data. I wonder why that would be? I think many others would take a different view. Especially those who do not confine themselves to the flat Earth version of the scientific method.

Flat Earth Community / Re: Flat Earth maps?
« on: March 04, 2022, 12:29:26 PM »
The article quoted on the page I linked says that this is false. In one example the angular diameter of Sirius is given as over one-tenth the visible diameter of the Moon.
Where do you get this tosh from Tom? Sirius over one tenth the visible diameter of the Moon!?! You don't actually believe that to be true do you?  The Moons visible diameter is half a degree give or take a few arc minutes. Lets call it 32 arc minutes.

That means one tenth of that is 3.2 arc minutes which is actually larger than the apparent size of Jupiter in a telescope at opposition. Jupiter was 47 arc seconds in size last August 20th when it was opposition. 47 arc seconds is less than 1 minute of arc (60") as I'm sure you know.  Do something for me Tom. Next clear night aim your telescope at Sirius and confirm for me that it looks over 190 arc seconds to you. That would be pretty amazing! That would be saying that the disk size of Sirius is over 3x the apparent size of Jupiter! Absolutely no way.

The little disk we see when we look at a star through a telescope is known as the Airy disk. The size of that depends on telescope aperture and is an optical effect only. The larger the aperture the smaller the Airy disk. Nothing to do with the star itself.

You link mentions about Kepler who was and still is renowned for his equations for planetary motion. His views about the size and distance of the stars however it seems were in need of some revision.

Flat Earth Theory / Re: What is going on with these observatories
« on: February 24, 2022, 11:37:05 PM »
I know its not the exciting answer that perhaps you are looking for but these lasers are simply producing artificial stars so astronomers can measure atmospheric turbulence prior to starting an observing run. They can they apply corrections in software to reduce the amount of noise in their images due to poor seeing.

Flat Earth Media / Re: New Photos of Moon suggest Flat Earth?
« on: February 10, 2022, 07:03:59 AM »
I am not in any way any kind of conspiracy theorist but I am pretty experienced when it comes to being an amateur astronomer. That Earthrise photo that Metatron has posted just doesn't look right. The large crater just left of centre looks suspiciously like the crater Copernicus for example which has a diameter approaching 50 miles. That being the case those footprints to the right of the crater are truly enormous!

So something just ain't right there...

Flat Earth Media / Re: New Photos of Moon suggest Flat Earth?
« on: February 09, 2022, 11:34:43 PM »
I found this sequence of images of the Moon transiting the Earth as seen from the Dscvr satellite.  Of which your image is one frame.

This is exactly what you would expect to see surely given that the Earth is much bigger than the Moon. How does this image in any way provide any evidence to suggest the Earth is flat?

As for your other image, this was taken obviously very much closer to the Moon compared to the Earth at over 380,000km away so again no surprises there.  At such close proximity to the Moon it would look a lot bigger than the Earth.

Seems to me that you are seeing what you want to believe rather than perhaps what the photos are actually showing you.

Regarding this comment you made earlier...

This satellite orbits more than a million miles above earth's surface
There is really no direction as such in space so what makes you say 'above' Earths surface rather than simply a million miles away from Earth?

Flat Earth Media / Re: New Photos of Moon suggest Flat Earth?
« on: February 09, 2022, 09:52:33 PM »
And how do we reconcile a satellite at an altitude of "several million miles" with a flat-Earth dome?
Absolutely. On one hand you have the FEers who seem happy to talk about satellite images of the Earth taken from an L point and then  on the other you get others who deny that satellites even exist but are just some sort of projection onto this non-existent dome.

So which is it?

Flat Earth Media / Re: New Photos of Moon suggest Flat Earth?
« on: February 09, 2022, 09:11:57 PM »
I couldn't help but take this most recent photo of the dark side of the moon by NASA's DSCOVR satellite very seriously.
So there is absolutely no chance that this sort of photo could have been produced by Photoshop?  Take an image of the Earth taken from space by a satellite and then paste a photo of a grey disk that looks kind of like the Moon and plant it on top of the image of Earth.  You could then resize the image of the Moon to whatever you wanted.

I couldn't help but take this most recent photo of the dark side of the moon
Don't you mean 'far side' of the Moon because through the course of a month the entire Moons surface gets illuminated by sunlight.

Most photos from the moon show the earth as a small dot
Care to provide a link to such a photo?  As seen from the Moon the Earth has a diameter on the lunar sky of 2.5 degrees or 5x the apparent diameter of the Moon as seen from Earth.

I have a friend who lives literally half a mile from me and who is a fellow amateur astronomer, physicist, radio comms engineer and licenced amateur radio operator.  So I don't need to rely on YouTube videos for evidence. I can try this for myself.

We got together a while back (after I had mentioned about researching what flat Earthers believe and their claim that the Moon is only 3000 miles away... to which he replied simply ... ah bless) and he showed me how easily he could send a radio signal towards the Moon and then receive the reflected signal.  It took about 2.6 seconds for the reflected signal to show up on his oscilloscope. If we say the mean distance of the Moon is 384,400km and the speed of light (= speed of a radio wave) is 299,792.5 km/s that gives an expected time (total dist/speed) of 2.56 seconds. So our reflected signal was just about bang on time.

We then tilted the transmitter away from the Moon by a few degrees and sent out another signal.  This time no received return signal.  So obviously the first signal had hit something and been reflected back while the second signal hit nothing and simply continued out into space. Strange... I thought it might have reflected off the 'dome'.

Having the equipment and actually being able to do these experiments for ones self is so much better than relying on YouTube sometimes.

I'm not sure why you guys like to come here and keep trying to claim this in repetition, but it is a falsity. Unguided Telescopic Equatorial Mounts only work for a few minutes before drifting off of the target star
If what you say here is true Tom then how come when using my 10" F8 (f/length = 2000mm) RC telescope with a ZWO ASI290 camera (FOV= 0.16deg by 0.09deg) I can track Jupiter for over an hour without any danger of it drifting off?  What do we mean by 'drifting off' here... drifting out of the FOV completely or just drifting within the FOV which is quite normal for an unguided mount. An FOV of just 9.6' x 5.4' is not exactly huge is it so what is your point here?

The telescope is mounted on an AstroPhysics 1200GTO mount. My system is only set up for OAG (off-axis guiding) so I cannot guide the mount while imaging planets. I don't need to in any case. I have got the mount polar aligned to an accuracy of better than 30" off the true NCP by regular checks using a QHY PoleMaster camera which is specially designed for the job. The performance of any mount is dependent on how well it has been set up. I have known people to align their equatorial mount directly on Polaris itself. By doing so they are immediately creating a 40' error into the tracking performance of the mount. In which case it would drift off target a lot sooner. But that of course is a human error and nothing more.

Unguided equatorial mounts are capable of very short exposures, as indicated by my original sources. This falls in line with what was claimed.
The purpose of guiding is to correct very small errors in tracking performance over extended periods of time. Errors that are due to either mechanical imperfections in the mount (PE or periodic error) or errors due to the accuracy of the polar alignment.

What you appear to have done is to pick a particular tutorial from the excellent collection from Starizona. You have then taken the meaning of that tutorial completely out of context in order to try and make out that it is supporting your opinion that equatorial mounts can only track successfully for very short periods of time. If you take that tutorial as a whole along with the others on the same site you will quickly realise that it is not saying that at all.

For visual observing such small errors in tracking are unimportant and an unguided equatorial mount is perfectly capable to tracking a celestial body for extended periods of time without any need for any adjustment. Certainly within the same field of view. If the target drifts out of the FOV then that is down to errors in polar alignment rather than anything else. Astrophotography by its nature places much higher demands on the performance of a telescope mount for obvious reasons. You need to be able to keep every star (each a point source) in every image on the same pixels of your camera for several hours. You don't need anywhere near the same level of performance for visual observing. In any case how does your claim about the tracking/guiding performance of equatorial mounts help your claim about the Earth being flat? Or is it just a case of trying to satisfy your desire to be right all the time?

Also, unguided equatorial mounts are perfectly capable of tracking the Sun for solar imaging for extended periods of time. You just have to set the mount to track at the solar rate instead of the sidereal rate. You will appreciate that it is pretty difficult to guide a mount during the daytime when no stars are visible!

So equatorial mounts are very much fit for purpose and do what they are designed to do very nicely. I'm not sure what the point of all this is anyway in relation to anything to do with what shape the Earth is. Equatorial mounts have always been designed to work on the global Earth that we all live on. The mount has a polar axis which is lined up with the Earths polar axis. That is what polar alignment means.

A telescope pointed at a celestial object must change its angle at 15 degrees per hour to keep that object in the center of view.
Not quite. There are 24 hours of RA (celestial equivalent of longitude) and so 360 degrees / 24h = 15 degrees per hour yes. But the sidereal day, measured as two successive transits of the meridian by a given star (e.g. Mintaka since it lies just 16" N of the celestial equator) = 23h 56m 4sec. So since the sidereal day is just 4 minutes less than 24h so a telescope must track a tiny bit faster than 15 degrees per hour but the difference is very small indeed.

It's not exactly 15 degrees an hour. The celestial bodies change speed throughout the day.
This is definitely not my experience after 40 years observing the sky.  The RA and Dec of stars doesn't change during the day and the speed of the Earth rotating doesn't change so what speed are you referring to here?

I'm just trying to imagine how tricky astrophotography would be if the speed of celestial bodies was changing throughout the day (and therefore night as well I assume). Tracking would be an absolute nightmare!

I've never seen a camera with an equally powerful lens as an astronomical telescope.
When used for photography, how 'powerful' the system is depends only on the focal length of the telescope. The magnification of a telescope when used for visual observation is decided by the ratio between the f'length of the telescope divided by the f'length of the eyepiece. So for example when used with my 13mm Ethos eyepiece my 10" RC telescope (f'length = 2000mm) gives a magnification of 2000/13 = 153.8x.

When used for photography we obviously replace eyepiece with a camera so the telescope becomes the lens of the camera. You can get T adapters which provide the interface between the lens mount of a DSLR and the focuser of the telescope. So with such a simple adapter I can easily attach my DSLR to my 10" RC telescope. The telescope then becomes effectively a 2000mm mirror lens as far as the camera is concerned. What you lose in this configuration is any of autofocusing capability of the DSLR but astronomers can use other tools such as a Bahnitov mask to focus manually instead.

Here is an image (of the Rosette Nebula) that I have personally taken. It is an unguided 15 minute exposure using my equatorial mount.

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