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Messages - robinofloxley

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1
Flat Earth Theory / Re: Angular size of the Moon
« on: October 31, 2020, 12:08:47 PM »
The method is based on this real experiment: http://www.etwright.org/astro/moonpar.html#:~:text=Parallax%20is%20the%20apparent%20shift,same%20point%20six%20hours%20apart and I used their images.

Great post mate, I've seen that experiment before, but unfortunately you'll probably get the Electromagnetic Accelerator theory thrown back as the explanation.  See, the "issue" with that experiment posits that the Earth is round and that light travels (to all intents and purposes for this experiment) in a straight line.  Just like Eratosthenes used shadows to prove that the Earth was round, the posit there was also that light travels in a straight line.  That FET says light curves upwards the further it travels, it means that Eratosthenes wasn't actually measuring the circumference of a globe, he was measuring the diameter of a flat disc.  Yes, flat Earthers believe that the Earth is some 25,000 miles in diameter, despite many different, yet repeatable scientific experiments showing that it is in fact just 7,900 miles in diameter.

Basically, the same argument will be used to dispute the effects of parallax, because that conveniently explains how two different people in different locations can apparently see different things.  The EA theory is full of holes, but it's the best they've got to explain the "day spot" on Earth and things like sunrise and sunset.  When I challenged it in a previous post all I got was "you are making a flawed assumption, or about 5 of them", yet was offered nothing to back up why his assumption wasn't equally flawed.  Interesting debates though.

To be honest, if the only counter argument is bendy light, then I'll be happy with that. It's such a weak argument, no way of calculating the effect, no way to test the theory at all. Can be used to explain away anything at all. Can't see the bottom of a ship? Horizon below level? Bridge curving over the horizon? Parallax? Bendy light solves all your issues because all it has to do is magically bend just the right amount where you want it and when you want it, to fit the observation. Yeah, right.

2
Flat Earth Theory / Re: Angular size of the Moon
« on: October 31, 2020, 08:40:57 AM »
Also, parallax does definitely work with the Moon. That's how we calculated the lunar distance before we had more advanced techniques (radar, laser), and the results were consistent.

Certainly does. I went through a worked example recently on that other site.

The method requires two observers a decent, known distance apart (mine were 2000km+ apart) who take simultaneous photos of the moon with identical DSLR cameras at the same (known) zoom settings. There is a requirement for there to be a nearby reference star in the frame.

I used these two photos as an example:





If you know the specs of the camera, from the sensor dimensions and the number of pixels, you can calculate the size of a single sensor pixel. From that, if you know the focal length of the lens, you can calculate the angular size of a pixel at that given lens zoom setting. That means you can convert a pixel distance on a photo to an angular distance.

Now the two images show that the relative positions of the moon and the reference star are different in the two images, even though the images were taken at exactly the same time. This difference is parallax, due to the two observers being in different locations.

With some simple editing software, overlay the two images so the moons and all the craters sit exactly on top of each other. Measure the pixel distance between the two reference star images, convert that to an angle, use some simple trigonometry using this angle and the distance between the two observers and you get an approximate value for the moon distance. Simple to do, works just fine. Doesn't require anything more complex than a digital camera.

The method is based on this real experiment: http://www.etwright.org/astro/moonpar.html#:~:text=Parallax%20is%20the%20apparent%20shift,same%20point%20six%20hours%20apart and I used their images.

3
Flat Earth Theory / Re: Latitude and longitude - please enlighten me
« on: August 13, 2020, 08:47:34 AM »
The question I have is how can we determine if your position in relation to the north star is based on a flat earth and refraction or a globe earth and refraction to determine if the claims that it's based entirely on a globe earth are supported or refuted by the evidence. As of now I don't know.
The fact that the North star has a certain altitude is merely an observation. You measure it in angles. How would that tell you anything about the shape of the earth?


I tend to agree after seeing the videos about it but it's a common belief that latitude is based on the earth being a sphere instead of based on how far you are away from the north star. What test could we devise to  determine if this is true or not.

I can stand at a certain point in my garden and measure the angular height of a tree at the other end of the garden. If I stand closer to the tree, the angle gets larger, further away and the angle gets smaller. What if anything I can deduce about the shape of the earth from this I really don't know and I don't know what additional test I could make to my tree measurement to determine the shape of the earth either.

If the tree was 323 light-years tall, then you could determine the shape by plotting the angles easily enough, just like we do with the North Star.

For a normal sized tree, if you get far enough away from it then the angle is going to behave differently if you are on a plane or a sphere. It will get lower faster on a sphere and eventually vanish. On a flat plane the angle will change rapidly when close, but far away it will slow down until it hardly changes at all.

Either way, if you plot the angle and distance measurements, they are only going to fit one shape.

The tree is quite tall, it's a Scots pine. I'm trying to imagine it 323 light-years tall, that would be something to behold!

Just to take a step back here and explain the thinking behind my original post, I've been trying to separate measuring the angle from measuring distances, because the minute we introduce distance, we get into shape and then bendy light/refraction, general relativity, non-euclidean geometries, interactive scale maps and all that stuff which goes around and around and gets nowhere with no agreement at all. The discussions become polarised.

Since you can measure an angle and/or measure a span of time, without measuring any distances at all, I'm saying let's just do that. We end up with two angles, a latitude and a longitude. We know that these are useful for navigation on the earth, because they've been used for centuries (especially latitude which goes back much much further).

9th century Arab sailors were using a kamal to determine latitude for navigation even before compasses were available.

What I want to know from flat earthers then is why they think measuring latitude with a kamal back in the 9th century can be dismissed as irrelevant because it's based on a spherical earth. It isn't, it's just measuring an angle, why can't you measure an angle on a flat earth?

I'd have liked to include longitude as well, but because that's more complicated and wasn't reliably used until the 17th C, then I'm happy to leave that out of the discussion too.

Honestly I'm just trying to backtrack to find some common ground we can all agree on. Haven't really got anywhere so far though.

4
Flat Earth Theory / Re: Latitude and longitude - please enlighten me
« on: August 12, 2020, 04:00:58 PM »
The question I have is how can we determine if your position in relation to the north star is based on a flat earth and refraction or a globe earth and refraction to determine if the claims that it's based entirely on a globe earth are supported or refuted by the evidence. As of now I don't know.
The fact that the North star has a certain altitude is merely an observation. You measure it in angles. How would that tell you anything about the shape of the earth?


I tend to agree after seeing the videos about it but it's a common belief that latitude is based on the earth being a sphere instead of based on how far you are away from the north star. What test could we devise to  determine if this is true or not.

I can stand at a certain point in my garden and measure the angular height of a tree at the other end of the garden. If I stand closer to the tree, the angle gets larger, further away and the angle gets smaller. What if anything I can deduce about the shape of the earth from this I really don't know and I don't know what additional test I could make to my tree measurement to determine the shape of the earth either.

5
Flat Earth Theory / Re: Latitude and longitude - please enlighten me
« on: August 12, 2020, 02:04:48 PM »
I agree that latitude is simpler and has been an integral part of navigation for much longer. Again it would be a good starting point to at least establish if latitude on its own is or isn't a contentious issue for FErs.

The central difficulty with longitude is that it's all about time and until the 18th C there wasn't a reliable way of keeping time accurately, by which time of course, a belief in a globe earth was pretty much universal. Having said that, unless time is somehow a concept which doesn't work on a flat earth, everything else about the method is observation of the heavens and observations are observations, the shape of the earth doesn't really affect the results.


The question I have is how can we determine if your position in relation to the north star is based on a flat earth and refraction or a globe earth and refraction to determine if the claims that it's based entirely on a globe earth are supported or refuted by the evidence. As of now I don't know.

I'm not sure if refraction is a significant factor for mid-latitudes because the north star will be quite high above the horizon (or however you are determining level). Near the equator, when polaris is very low, sure.

I don't really see how measuring the angular height of something could be connected to the shape of the earth. Clearly we can measure the angular height and almost by definition if we measure this height/angle from two different locations and find it to be the same, then we say these are at the same latitude. We know that ancient mariners used things like kamals and this enabled them to find their way back to the correct port when they needed to, so the system clearly works, whether the earth is flat or some other shape.

6
Flat Earth Theory / Re: Latitude and longitude - please enlighten me
« on: August 07, 2020, 12:20:04 PM »
I'd go further and say I don't believe there is an issue with longitude either. In principle, finding your longitude is easy. Find the exact time when the sun was due south at Greenwich UK. Find the exact time when the sun is due south at your current location. Work out the time difference. If it's 1 hour, then you are 15° away from Greenwich. This can work on a flat earth just as well as a spherical one, it's simply making use of the fact that the sun appears to travel across the sky at 15° per hour, nothing more. The sun certainly does this, it's easily observed, so if the earth is flat, then it's doing this on a flat earth, so the method still works.


The main issue that I have with longitude being shape agnostic is that it a lot more complicated to calculate and was not really done by ancient navigators when the FE concept was much more mainstream than it is now.  It's more modern. It's not something you can calculate with sometime as simple as some rope and a board. Claims that it is based on a spherical coordinate system, from my perspective, are much more challenging for me to understand or offer an alternate theory to.

With latitude it seems to me that there is strong evidence that a navigator who calculated latitude and thought the earth was flat would do so in a similar way to a navigator who thought the earth was round.

I agree that latitude is simpler and has been an integral part of navigation for much longer. Again it would be a good starting point to at least establish if latitude on its own is or isn't a contentious issue for FErs.

The central difficulty with longitude is that it's all about time and until the 18th C there wasn't a reliable way of keeping time accurately, by which time of course, a belief in a globe earth was pretty much universal. Having said that, unless time is somehow a concept which doesn't work on a flat earth, everything else about the method is observation of the heavens and observations are observations, the shape of the earth doesn't really affect the results.

7
Flat Earth Theory / Re: Latitude and longitude - please enlighten me
« on: August 05, 2020, 08:49:20 AM »
I've read a number of posts where latitude and longitude are dismissed by FErs because they are based on a globe earth.

Robin,

I've researched this and I'm also confused about the claim because we have been able to navigate using the stars without using the words "Longitude" and "Latitude"




In terms of Latitude it does not appear to me to be based on a spherical coordinate system. It appears to be based on where you are, in relation to the North star. This was made clear to me when I learned about the Kamal.

https://en.wikipedia.org/wiki/Kamal_(navigation)


The video below discusses the Kamal around 2 minutes.



So is it only the longitude part of the system which is based on a spherical earth?

I agree, you don't need to be on a spherical earth for latitude to have a meaning and it's undoubtedly useful for navigation. I would really like to hear from a range of FErs whether they would accept this and if not, why not?

I'd go further and say I don't believe there is an issue with longitude either. In principle, finding your longitude is easy. Find the exact time when the sun was due south at Greenwich UK. Find the exact time when the sun is due south at your current location. Work out the time difference. If it's 1 hour, then you are 15° away from Greenwich. This can work on a flat earth just as well as a spherical one, it's simply making use of the fact that the sun appears to travel across the sky at 15° per hour, nothing more. The sun certainly does this, it's easily observed, so if the earth is flat, then it's doing this on a flat earth, so the method still works.

In practice it's not quite as simple as that because the 15° per hour is only an average, it does speed up and slow down a bit throughout the year, but there are known ways to correct for this (see equation of time https://en.wikipedia.org/wiki/Equation_of_time).

Very informative video by the way.

8
Well I don't consider the earth itself to have an interactive surface with a scale that changes as you move across it, so I don't particularly care that Bing has an interactive scale.

But it is. When you see something very far away that is very small your brain knows that, because that small thing is very far away, the scale of the item is large. When I see the mountains, which are just a few inches tall off on the horizon my brain passively understands. When I look out the airplane window at 30,000 feet I know the scale of the surface of the earth has changed and, what was a very small distance, from the airplane is a much larger distance from the surface of the earth. If I took a picture from the airplane and drew a scale on it that scale would be much different than the scale from a picture taken at ground level.

Well I find that a very odd definition of an interactive scale. Using that logic I can look at a wall map and take a step backwards and say the scale has changed. OK, so on that basis, I'll say map 2 has an interactive scale because it looks smaller from 2 metres away on my screen than 1 metre.

If anything, that makes me less likely to think it represents any kind of reality.

I just gave an example of how, in the real world, a video of the surface of the earth should have an interactive scale.



Secondly, where exactly is the south pole on a Bing map?



It's not a single point, it's a horizontal line that stretches all the way along the base of the map whether you are zoomed in or not.

That's funny because I didn't see a line. I saw an area of land on Antarctica when i search for south pole on bing.

Well in my book, the (geographic) south pole is a physical point on the earth I could visit and stick a pin in, located at latitude 90S.

Try zooming in or out as much as you like on Bing maps, locate the furthest south point you can, right click (for a Windows user) and it shows you the position you clicked in latitude/longitude coordinates. You'll find the furthest south you can get is -85 or 85S. Similarly, the furthest north you can go is 85N. Basically Bing is not showing you the last 5 degrees at the top or bottom. That's 69 miles of the earth you are not seeing at each pole. You don't even have a north or south pole on your Bing map. At least map 2 shows the north pole correctly.

The reason you can't go all the way to 90° is that mathematically it would blow up because you end up with an infinitesimally small point at the exact geographic pole where all the longitude lines converge. I'm surprised that they actually ditch a whole 5°, but I guess that makes things easier to compute.


That's no more realistic to me than the rim of the circle on model 2. At least with map 2 I can put a pin in the exact location of the north pole. Map 2 doesn't say anything about there being a wall, it's a flat 2D surface. Sure, many FErs add the ice wall part, but that's not something you can deduce just from looking at the map.

If you search for south pole Antarctica on Bing you don't see a map. Even if you did see a line that would not change the fact that one model has a south pole and no ice barrier perimeter and one does.

Also, I don't consider 1&2 to be different models at all, just different presentations of the same information.

You are seriously arguing semantics about the word "model". Fine then. What "presentation style" do you believe most closely depicts the planet that you live on.

"presentation style" 1:

-depicts the earth as a defined area with a defined edge
-depicts the earth as having a great ice wall around this perimeter edge
-depicts the earth as not having a south pole
-not supported by know travel paths/times
-not taught in schools all over the world as a "presentation style" of the surface of the earth


"presentation style" 2
-depicts the earth as an interactive surface with no defined edge
-depicts the earth as not having a great ice wall (partly because there is no perimeter edge)
-depict the earth has having a south pole
-supported by know travel paths/times
-taught in schools all over the world as a "presentation style" of the surface of the earth


So style 2 doesn't show north or south pole, since it misses out parts of the earth. What is the north and south boundary of the map, beyond which you cannot go? Looks like an edge to me. The southern boundary is entirely white. Is this not an ice wall? How is this different from the white edge of style 2? Why do you say one area of white is an ice wall and the other area is not?

Actually a number of schools are no longer teaching using Mercator (https://www.theguardian.com/education/2017/mar/19/boston-public-schools-world-map-mercator-peters-projection) because they want to offer "something closer to the geographical truth than that of traditional school maps". It is acknowledged that Mercator portrays Europe and the USA as bigger (and by implication more important) than they actually are in relation to regions such as Africa and South America. Basically it's an old fashioned view of the world and gives children the wrong idea. In all probability, the majority of schools still use Mercator, but it's changing as people become more aware.


Both models are accurate in some respects and inaccurate in others. Model 1 is good around the equator and poor around the poles. Model 2 is good around the north pole, poor around the equator and poor around the south pole. How am I supposed to come to any kind of conclusion about which model is better than the other?

I thought you just said they were not models? Now you are saying they are models. The Bing map "presentation style" has an interactive scale which makes it much more accurate both around the poles and around the equators


In the very next sentence I use the term "model/projection" for extra clarity because you use the term model for what I would describe as a projection. To me, you can't view a model. The model is mathematics and data. Viewing a 3D globe on a 2D screen is an orthographic projection. You are looking at the projection, not the model. In my view, there is one model, based on a spherical earth and many projections of that model. Pseudo 3D on a 2D screen (i.e. Google 3D zoomed out) is one, "models" (your usage) 1 & 2 are others. I term these projections, you say model, that's fine, I apologise, my wording was careless.


I can use some GIS software to zoom in as much as I want to on a particular area of a map using either model/projection and I can use haversine to calculate distances on either model (and they will agree with each other). I know this isn't instant and interactive, but who cares? I certainly don't.

Can you show me, online, where anyone has made an interactive map out of the flat disk, great ice wall, "presentation style" of the surface of the earth

I'd be very surprised if such a thing exists, why would anybody bother? But if you want to show me a screenshot of a zoomed in area on Bing maps with a scale, I'll gladly have a go with some GIS software and reproduce it for you using the "model" 2 north polar azimuthal equidistant projection.

9
Both models 1 & 2 represent the earth equally well

How so? One represent the earth as an interactive surface with ice at the north pole and the south pole and a second one represent the earth as a flat circle with a great ice wall around the perimeter. They are two totally different models of the earth.


Well I don't consider the earth itself to have an interactive surface with a scale that changes as you move across it, so I don't particularly care that Bing has an interactive scale. If anything, that makes me less likely to think it represents any kind of reality. Secondly, where exactly is the south pole on a Bing map? It's not a single point, it's a horizontal line that stretches all the way along the base of the map whether you are zoomed in or not. That's no more realistic to me than the rim of the circle on model 2. At least with map 2 I can put a pin in the exact location of the north pole. Map 2 doesn't say anything about there being a wall, it's a flat 2D surface. Sure, many FErs add the ice wall part, but that's not something you can deduce just from looking at the map.

Also, I don't consider 1&2 to be different models at all, just different presentations of the same information. In much the same way you can create a spreadsheet with a bunch of numbers and then create line charts, pie charts, bar charts etc. etc. all representing the same data in different ways. All presentations are valid, you choose the most appropriate for the circumstance.


If you won't answer that question would you answer the questions?

1. Does the planet that you live on have a South Pole?
Yes
2. Does the planet that you live on have a great ice wall encompassing the entire planet?
No

Yet you refuse to acknowledge that a model of the earth with a south pole and no perimeter ice wall is a more accurate representation of the planet that you live on. Why is that? How can you say that a model of our earth with a great ice wall and no south pole is just as accurate as a model of our earth with no great ice wall and a south pole??

Both models are accurate in some respects and inaccurate in others. Model 1 is good around the equator and poor around the poles. Model 2 is good around the north pole, poor around the equator and poor around the south pole. How am I supposed to come to any kind of conclusion about which model is better than the other?

I can use some GIS software to zoom in as much as I want to on a particular area of a map using either model/projection and I can use haversine to calculate distances on either model (and they will agree with each other). I know this isn't instant and interactive, but who cares? I certainly don't.

10
First of all thank you for acknowledging that you had misinterpreted your interrogation of the Flight Record; I think you will earn respect for that from the other posters. 

Thanks. Now I would really appreciate it if you would answer my question. Which of the two proposed FE models do you believe most closely resembles the planet that you live on and why?

I know these questions were primarily aimed at DuncanDoenitz, but here are my answers:

Both models 1 & 2 represent the earth equally well, because they are both projections of the same globe model and no projection is intrinsically better than any other projection. There are some instances where one projection is more useful than another, so for example travelling in arctic regions, 2 would be better than 1. There are plenty of occasions when another projection altogether would be a better choice than either of these, so for example, for planning a VFR flight in the UK, I'd want a transverse mercator. Bing would be completely and dangerously useless for planning such a flight.

The Bing map is dynamic and has zoom and pan features and a measuring tool, but it would be perfectly possible to add these to map 2. Google maps for example when zoomed out can be displayed as either a web mercator (identical to Bing) or as a 3D globe, and you can re-project either way from one to the other so there's no reason Google (or Bing) couldn't add other map projections as well, if they thought it was worth doing. When you zoom in or measure in Google maps, it doesn't matter whether you start from a zoomed out globe or a web mercator, you end up with the same result. Similarly, since you can easily project a web mercator to a globe, Bing could easily add a 3D globe view if they wanted.

If you won't answer that question would you answer the questions?

1. Does the planet that you live on have a South Pole?
Yes
2. Does the planet that you live on have a great ice wall encompassing the entire planet?
No

If you think the earth does have a south pole and no great perimeter ice wall then then you would believe that a bing map type interactive FE model would most accurately depict the planet that you live on.

No, they are both equally useless for areas around the south pole. A south polar azimuthal equidistant would be a much better choice.


The problem with all of these projections is the distortion of the image, generally the further from the centre of the Polar Map, or from the equator of the Mercator Projection, more distortion is introduced.  Look at Australia in the Polar Map; if it was that long and thin, don't you think the Aussies would have noticed? 

This is why the more modern online maps have an interactive scale which changes depends on where you look and how far in you zoom.

11

Here is a model of the earth in which the earth is represented as a flat plane:
https://www.bing.com/maps

I will call this FE model 1

There is this thing in law called beyond reasonable doubt. The key word here is reasonable. It is the standard against which evidence is judged. Take out the word reasonable and nobody is convicted of anything ever.

You have been shown, endless times, documentation from Microsoft, the authors of Bing, that they use a spherical globe model with a particular radius and that they use spherical trigonometry (specifically the Haversine formula) with this model. You challenged the evidence and we were able to demonstrate a 100% correlation between distances on Bing maps and distances calculated based on the spherical Haversine formula, using Microsoft's own published figures for Earth's radius.

The evidence you were shown passed the threshold for "beyond reasonable", carried on mounting up and left "beyond reasonable" as a distant spec in the rear view mirror. Bing is simply not using an FE model.

12 people like you on a Jury trial, consistently applying your criteria for judging evidence, would collapse the justice system.

12
Flat Earth Theory / Re: Latitude and longitude - please enlighten me
« on: June 30, 2020, 04:32:23 PM »
I think you are probably right, FE and RE should be able to agree on the latitude (and longitude) for any point on the earth.

Not even 'probably'. For those who dislike the theory of declination, here is a neat video showing how to locate the southern celestial pole.

It’s the pure Zetetic method, i.e. working directly from observation rather than supporting the observations, partly or wholly, on some theory.

You're right we should be able to agree. The question then becomes, will we be able to agree?

Interesting video. So much easier in the northern hemisphere.

13
Flat Earth Theory / Re: Latitude and longitude - please enlighten me
« on: June 30, 2020, 02:09:10 PM »
Doesn't the altitude of the sun at its highest point during a day depend on the time of the year ?

It does, and is known as the Declination. You can get that number from tables, but again it does not depend on any assumption about the shape of the earth. You can simply observe the declination each day at local noon (i.e. at zenith) and note it down, so you have a number for each day of the year.

Then take a sighting with the sextant to find the altitude of the sun at local noon. Latitude then given by the following formula:

    LAT  =  90 - ALT + DEC

Simple. Involves no assumptions about the shape of the earth, so FE and RE should agree on the latitude for any point on the earth. Likewise, if they know London (Greenwich) time, they both agree on the longitude.

Where they will profoundly disagree is on the distance implied between two points on the earth's surface. This will depend on the chosen map, about which FE will internally disagree. But assuming FE likes the AE map, and RE the globe, they will compute the distances differently, radically so the further south they get.

I think you are probably right, FE and RE should be able to agree on the latitude (and longitude) for any point on the earth. The problem is, I've never heard a FEer actually agree to that, all I've ever heard is "can't use latitude/longitude because that's based on a globe". It's a very broad statement and I've been trying to break it down into two separate issues, i) latitude/longitude for position ii) distances based on latitude/longitude. I would love to hear a FEer say, "yes, i) is OK, but ii) is not". Then at least we know where we all stand. Just can't get an opinion on this from their side unfortunately.

14
Flat Earth Theory / Re: Latitude and longitude - please enlighten me
« on: June 30, 2020, 08:30:19 AM »
Doesn't the altitude of the sun at it highest point during a day depend on the time of the year ? Maybe at one of the equinoxes you would be a good choice ?

Yes, I think if you are in a suitable (well north of the equator) static location and you aren't in a hurry, personally I'd use the Polaris method for latitude. The sun changes its altitude during the day and throughout the year and you really don't want to look directly at it. Polaris just sits there, unmoving and you can look straight at it. If you're on the open sea, south of the equator and it's daytime, use the sun for sure.

But really whatever works for you, so long as it gives you the right answer. The key idea here is, however you choose to do it, you end up with a pair of angles which uniquely define your position and that would work, globe or flat.

Would love to hear from the FE folks too.

Yes, it's a bit pointless all us RErs discussing this because we're not going to disagree (I assume). Disappointing that we're not hearing much from them.

15
Flat Earth Theory / Re: Latitude and longitude - please enlighten me
« on: June 22, 2020, 10:11:46 PM »
  "I think it's because latitude/longitude have just become forever associated with the globe and that's what's causing the problem for those who don't believe in the globe."

You've answered your own question there. Plane measurements associated with a globe through spherical calculations . That's the objection.


Well I've taken a guess at what the objections might be, but I want to know if that's what FErs actually object to, or is it something else?


From your OP.

 "Fundamentally (if you live in the northern hemisphere), your latitude is easily determined. It's simply the altitude of Polaris from your location. It's not an absolute value in miles, km or light years, because to determine that you'd need to know how far away Polaris is and in times past, that wasn't possible to determine. What we do instead is measure the angle from the horizon to the star, because that's easily done and doesn't require you to know any distances."

Point 1 . You assume Polaris is known to be a vast distance and point 2 - you assume that in past times the distance to Polaris wasn't possible to measure .


No, we've been here before and this has been addressed already..

Good description of how we can measure lat and long in the northern part of the world.

However you state the globe theory preconceived assumption that Polaris is at an extreme distance thus its light rays are basically parallel leading to the conclusion that any change in measured angle of elevation to the star is a product of the curvature of this globe .

No I've not stated anything about the distance to Polaris (extreme or otherwise), other than simply saying that in times past, the distance was not known, but we can however use an angular measurement instead, which works independently of distance. For instance I can measure the angular height of a tree at the bottom of my garden from my current position. It doesn't tell me anything about the actual height of the tree or how far away it is or for that matter, what shape the earth is.

Equally, it doesn't matter whether the light rays from Polaris are parallel or not, just that whenever you measure the angular elevation of Polaris from the same position, you are always going to get the same value and if you move north or south of that position, you will get a different value, which will increase as you move north and decrease as you move south.

To which you replied...

Sorry Robin , I misread your OP about distance to Polaris .


See Brahe's model for the distance to the stars for one example and I'm sure triangulation of distance has been around for a long time .

Point 3. We do not measure elevation of Polaris from the horizon - we measure elevation from the horizontal plane 

If you make a post containing assumptions you are confusing the issue.

I'm no sailor and I've never used a sextant, however my understanding of how these are normally used when in open water is that you adjust two images until they overlap. One of the images is the celestial object, sun, moon, planet or star and the other is the horizon. Determining the horizontal plane on a rolling ship is not easy. I'm not going to bother arguing about this though, it's detail, it doesn't fundamentally change the methodology, it would just lead to very slightly different results. If I'm wrong, then I'm wrong and quite happy to concede the point. To me it's a fairly unimportant detail to the overall process.

So just to reiterate. I don't assume the distance to Polaris is known to be a vast distance. The distance is utterly irrelevant if all you are doing is measuring its angular height above a datum (horizon or horizontal plane, I don't really care). I don't care if the light rays are parallel either. That won't stop you measuring an angle. Yes, I do assume that in ancient times we had no way to determine the distance to a star. I believe Tycho Brahe proposed measuring stellar parallax, but didn't have equipment capable of doing so. But again, whether they could or couldn't measure stellar distances is completely irrelevant to a method which uses angles, not distances, so I'll happily ditch that assumption and say in times past, people may or may not have been able to measure stellar distances, but since we're using angles, it makes no difference whether they did or whether they didn't.

16
Flat Earth Theory / Re: Latitude and longitude - please enlighten me
« on: June 22, 2020, 03:39:14 PM »
I don't get your point . Last line of your OP .

"So is that it? Are latitude/longitude OK by themselves, but the distances are not? What are the actual objections?"

I have put forward the objections . Why should FE accept an ellipsoid model coordinate system as being suitable to describe earth ?

GPS and the globe are not latitude longitude systems of earth ,  yet they are offered up as proof of a globe because by RE . Why do you think that doesn't deserve objection ?

RE is fond of telling us FE distances don't add up on their imaginary model . This is why the distances are important .

Your last sentence makes no sense - can't fathom that out.

Somehow or other I'm just not managing to explain myself very well and I keep trying different ways to say the same thing. All I can do is keep trying I guess. I don't honestly think there's much if any disagreement with each other. Anyway here goes...

Latitude and longitude pre-date GPS by centuries, so by all means discard any arguments based on GPS, not that I'm using any here.

If you were completely lost, but you had a basic set of instruments (and I think we agree what those are), none of which rely on a globe to function (you just point them at things and measure angles or check timings), you could determine your latitude and longitude. If I had the same basic set of instruments, plus a compass, and you could tell me your position, then in theory I could find you. I just need to travel north or south until we're at the same latitude and then east or west until we're at the same longitude and we should meet. Distances don't matter. This process just works whether the earth is a globe or flat - correct?

So from my point of view, for this purpose and this purpose only, nobody can object to latitude/longitude. But they do. Frequently I come across "you can't use latitude/longitude because it's based on a globe". Well how is this based on a globe? Don't go talking about measuring distances, we only have these basic instruments, we have no means to measure any distances.

In order to determine the truth of this, I'm discarding GPS, spherical geometry, everything globe related. Pretend humanity had never even considered the idea that the world was a globe, pretend we've never invented the ruler or tape measure or even the concept of a distance. Is determining your position (latitude/longitude) possible? Well clearly it is. Is it useful? Again, clearly it is. Why then is it constantly rejected in arguments?

I think it's because latitude/longitude have just become forever associated with the globe and that's what's causing the problem for those who don't believe in the globe.

You keep bringing up distances, well you keep objecting to a point I'm just not making. Leave distances out of it and then tell me what's wrong with latitude/longitude.

17
Flat Earth Theory / Re: Latitude and longitude - please enlighten me
« on: June 21, 2020, 05:08:04 PM »
Yeah nice , we agree about the equipment and methodology , and you are correct this is indeed compatible with flat or globe earth .
                  I disagree with your next bit. The set of geometric observations you make will tell you , without preconception , which shape is a better fit for a model of earth .

On a perfect sphere with the pole star at immense distance , light rays would be parallel to the axis of the globe and all degrees of latitude should be equal distance apart since they are governed by the curve of the sphere.

On an oblate sphere ,same distant polestar,  degrees of latitude will lengthen to the North.

On a plain degrees of latitude will shorten to the North only if the polestar is relatively close .

God knows about the pearoid.

It's probably impossible to get true accurate readings due to the diffraction /diffusion etc caused by the air but the general shape should be discernable.

What I mean is, you can determine your position and that by itself doesn't force you to accept a particular model. It's only if you start measuring distances between pairs of locations that the realities of the model need to be considered and I think it's this follow on measuring that's the real problem for FE believers, but it's hard to tell because the argument always seems to be along the lines of "can't use latitude/longitude because that's based on a globe". Well I'm just saying that actually, if you limit yourself to determining position, and put aside the tricky topic of distance, then all you are doing is using some pretty basic instruments to make some simple to understand observations.

I completely agree that if you start measuring distances, that will lead you to draw conclusions about the shape of the earth and if you lump the two together (position+distance), then you just get the standard "can't use that, it's based on a globe" response.

18
Flat Earth Theory / Re: Latitude and longitude - please enlighten me
« on: June 21, 2020, 02:00:14 PM »
Latitude is determined by measure of the angle of pole star above the horizontal plane form position of measure , not the horizon . The plane is found by plumbline and level , the angle of elevation by sextant and quadrant .

Use the stars to determine the meridian . Zenith sector, transit scope , survey instruments . You need to see the pole star . It's not visible during daylight which is why I wouldn't use the sun . Every star will cross the meridian at it's zenith . You will then have a meridian along which you will also have observed and measured degrees of latitude given by the pole star - that point above the geographical N point . Call it whatever you want .


OK, well that's my proposition 1 then. Quite happy with the equipment and methodology. So really that's all my proposition 1 is about. I believe this is compatible with either flat or globe earth, it's just a set of observations you make, it doesn't by itself tell you what shape the earth is. So my question to anybody who believes in a flat earth is, do any of you have a problem with this and if so, what is it?

I take it you and I at least can now agree that this is an acceptable method / co-ordinate system for describing a position somewhere, anywhere on earth?

19
Flat Earth Theory / Re: Latitude and longitude - please enlighten me
« on: June 20, 2020, 09:57:56 PM »

"degrees of latitude along a meridian" has no meaning on FE. As mentioned earlier, where would you draw the angle between the two vectors?

A meridian is any straight line from N to S - not hard to understand .

Just to make my position clear .

I am not taking a FE or RE stance on latitude . A survey of length of successive degrees of latitude along a meridian , with respect to the pole star , will give a clear indication of the shape of the land . It's just geometry . If you don't know the distance to the pole then it can be calculated from those results .

This is the point , the results are determined by measurement not theory. Any coordinate system will give unique values to each point but if want them to conform to the real shape of earth then you have to deduce that shape .

No, I get that. I think I understand your position well enough. Without wishing to put words in your mouth, I'd say you were happy enough to accept my proposition 1) - that you can use latitude/longitude in either model to pinpoint an exact position and as for 2) potentially you can determine whether or not you can calculate accurate distance from latitude/longitude, well then, that can be checked/investigated by taking survey measurements along a meridian.

As I said, I was hoping to get a range of opinions from flat earthers on 1) & 2) separately, but not much engagement so far.

For proposition 1 i'd have to say no . What your saying ,it seems to me , is that you can use any coordinate system . Well you can , and it is true that each will give unique results . But there is only one coordinate system which can rightly be called a latitude/longitude coordinate system - the angle of latitude as measured from the pole star . All other coordinate systems are based on math models - not reality . 

Pole star latitude/longitude system cannot fit both FE or RE model . It will fit only one .

You can distort the results of survey by applying a set of calculations which will enable you to map earth as any shape you wish but it won't be reality .

OK, sorry, I thought we were on the same page. Seems not to be the case. Let me have another go at explaining. I won't bother with 2), I'll just stick with proposition 1) for now, see if there is some common ground or not.

For proposition 1, this is just about latitude/longitude. That's the only coordinate system I'm talking about. The units are degrees, either expressed as degrees-minutes-seconds (and fractions thereof) or decimal degrees, whichever you like, no preference on my part. Latitude to be measured however you like really. Quite happy with angular distance from horizon to Polaris (or equivalent in the southern hemisphere), measured with a sextant, quadrant, backstaff, or something else, whatever you prefer, so long as the values it gives are sensible. For longitude, I'd suggest time difference between either the sun or a suitable star transiting due south at a fixed meridian (I'd suggest Greenwich, but flexible on that) and same event occurring at the observer's position. Time difference converted to an angle based on the sun moving at 15 degrees per hour or the sidereal day length if using a star transit. But any sensible method to measure longitude acceptable.

I'm not suggesting a coordinate system based on math calculations, just observations, so long as you don't consider converting a time difference to an angle for longitude to be a math calculation in the sense I think you mean it.

If you are happy with the basic idea of latitude and longitude and you want to suggest suitable equipment and/or methodology, I'm pretty confident we can find agreement there.

20
Flat Earth Theory / Re: Latitude and longitude - please enlighten me
« on: June 19, 2020, 02:09:14 PM »
Just to make my position clear .

I am not taking a FE or RE stance on latitude . A survey of length of successive degrees of latitude along a meridian , with respect to the pole star , will give a clear indication of the shape of the land . It's just geometry . If you don't know the distance to the pole then it can be calculated from those results .

This is the point , the results are determined by measurement not theory. Any coordinate system will give unique values to each point but if want them to conform to the real shape of earth then you have to deduce that shape .

No, I get that. I think I understand your position well enough. Without wishing to put words in your mouth, I'd say you were happy enough to accept my proposition 1) - that you can use latitude/longitude in either model to pinpoint an exact position and as for 2) potentially you can determine whether or not you can calculate accurate distance from latitude/longitude, well then, that can be checked/investigated by taking survey measurements along a meridian.

As I said, I was hoping to get a range of opinions from flat earthers on 1) & 2) separately, but not much engagement so far.

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