Moon features

If the Moon is a disc, why does it never appear foreshortened from some parts of the world?
If the Moon is a sphere, why do we see the same side of it from everywhere?
Discuss this here.

If the Moon is a disc, why does it never appear foreshortened from some parts of the world?

Bendy light.

Quote from: The Knowledge on April 05, 2012, 01:29:01 PM

If the Moon is a disc, why does it never appear foreshortened from some parts of the world?

Bendy light.

Sorry, that's been disproved. Try harder.

The face if the moon does not have to always be perpendicular to the face of the Earth. The moon's face can't tilt and show the same view to everyone. Personally, I think that the moon is a sphere, or at least a semi-sphere, that can tilt and wobble.

The face if the moon does not have to always be perpendicular to the face of the Earth. The moon's face can't tilt and show the same view to everyone. Personally, I think that the moon is a sphere, or at least a semi-sphere, that can tilt and wobble.

I can't work out what you're trying to say here, other than the moon is not flat. Do you have an explanation of why it shows the same side to people everywhere?

who thinks the moon is a disc?
anyone with a cheap telescope can verify it is at least semi spherical, and as a Zetetic, semi - spherical is NOT planar.
even the faqqers agree the moon is spherical.

who thinks the moon is a disc?
anyone with a cheap telescope can verify it is at least semi spherical, and as a Zetetic, semi - spherical is NOT planar.
even the faqqers agree the moon is spherical.

John Davis thinks it's a flat metal disc (probably covered with moonshramps.)
Anyway, disputing what people believe is avoiding the question. You think it's spherical, so explain why it looks the same everywhere.

Quote from: iwanttobelieve on April 05, 2012, 04:56:06 PM

who thinks the moon is a disc?
anyone with a cheap telescope can verify it is at least semi spherical, and as a Zetetic, semi - spherical is NOT planar.
even the faqqers agree the moon is spherical.

John Davis thinks it's a flat metal disc (probably covered with moonshramps.)
Anyway, disputing what people believe is avoiding the question. You think it's spherical, so explain why it looks the same everywhere.

It's orbiting the Earth and spinning on it's own axis at such a speed that it always presents the same face to the surface, making it appear to the inhabitants on the surface as though it's static. Simple, no?

EDIT: It seems I misunderstood the question. Still. Food for thought?

The moon cannot be seen across the disk to where you can see its side. It is only visible when it is over your present location. This is due to a combination of perspective and refraction. See Earth Not a Globe for additional information.

The moon cannot be seen across the disk to where you can see its side. It is only visible when it is over your present location. This is due to a combination of perspective and refraction. See Earth Not a Globe for additional information.

Do you have a direct link?

Quote from: Tom Bishop on April 06, 2012, 01:10:52 PM

The moon cannot be seen across the disk to where you can see its side. It is only visible when it is over your present location. This is due to a combination of perspective and refraction. See Earth Not a Globe for additional information.

Do you have a direct link?

In Earth Not a Globe the primary cause for the descent of celestial bodies is natural perspective, and the ultimate cause for disappearance is due to terrestrial refraction:

"The question, 'how is it that the earth is not at all times illuminated all over its surface, seeing that the sun is always several hundred miles above it?' may be answered as follows:--

First, if no atmosphere existed, no doubt the light of the sun would diffuse over the whole earth at once, and alternations of light and darkness could not exist.

Secondly, as the earth is covered with an atmosphere of many miles in depth, the density of which gradually increases downwards to the surface, all the rays of light except those which are vertical, as they enter the upper stratum of air are arrested in their course of diffusion, and by refraction bent downwards towards the earth; as this takes place in all directions round the sun--equally where density and other conditions are equal, and vice versā--the effect is a comparatively distinct disc of sun-light."

That would hold true if light from the sun were a collection of laser beams, where the location of the beam's endpoint could be determined empirically. It isn't a collection of lasers though, so it isn't plausible to assume all of the light would bend to hit the surface at some given radius from the sun. That would be an interesting thing to observe, though...

To properly model this, you would have to consider the rays from the sun in a probabilistic sense, whereas you could not determine the final location of photons empirically, but would rather have to rely on a mathematical prediction. The probability distribution function for the radius reached by the sun's rays in this case would not simply terminate at some specific distance from the sun as they would with lasers, but would gradually taper off to zero (despite never reaching it) as radius increases.

Simply put, you'd always be able to see the sun given that flat-earth model. It would grow fainter and fainter as you moved away, but it would always be visible.

The moon cannot be seen across the disk to where you can see its side. It is only visible when it is over your present location. This is due to a combination of perspective and refraction. See Earth Not a Globe for additional information.

And you accuse me of talking rubbish? Say I'm in the UK, and someone else is in South Africa. It's night time. The Moon - a sphere according to you - is visible in the sky from both places. However, it's not directly overhead to either of us, and neither is it directly overhead to a third observer in Saudi Arabia. However, when we look at it we all see the same thing, despite your belief that it's only 3000 miles up above the surface and each observer is more than 3000 miles apart. Perhaps you might like to draw a triangle with the upper vertex representing the moon and the other two representing observers (or imagine a tetrahedron to include the third observer) and then explain how we are all able to see the exact same side of it, and furthermore, why we see that side and not any other, and why as it moves from east to west across the sky that view does not change.
Typing bollocks about perspective and refraction does not address the question,  neither do your links, neither is it explained anywhere in that well known fictional pamphlet Earth Not A Globe.

Quote from: Tom Bishop on April 06, 2012, 01:10:52 PM

The moon cannot be seen across the disk to where you can see its side. It is only visible when it is over your present location. This is due to a combination of perspective and refraction. See Earth Not a Globe for additional information.

And you accuse me of talking rubbish? Say I'm in the UK, and someone else is in South Africa. It's night time. The Moon - a sphere according to you - is visible in the sky from both places. However, it's not directly overhead to either of us, and neither is it directly overhead to a third observer in Saudi Arabia. However, when we look at it we all see the same thing, despite your belief that it's only 3000 miles up above the surface and each observer is more than 3000 miles apart. Perhaps you might like to draw a triangle with the upper vertex representing the moon and the other two representing observers (or imagine a tetrahedron to include the third observer) and then explain how we are all able to see the exact same side of it, and furthermore, why we see that side and not any other, and why as it moves from east to west across the sky that view does not change.
Typing bollocks about perspective and refraction does not address the question,  neither do your links, neither is it explained anywhere in that well known fictional pamphlet Earth Not A Globe.

You are assuming that the light between the observers and the celestial bodies are traveling in straight lines. Light from the moon's face is bent to far off places, whereby light which is emanating from the moon's sides are lost to refraction entirely, which is why the moon is not at all times visible above the surface of the earth.

You are assuming that the light between the observers and the celestial bodies are traveling in straight lines. Light from the moon's face is bent to far off places, whereby light which is emanating from the moon's sides are lost to refraction entirely, which is why the moon is not at all times visible above the surface of the earth.

Could we see a visual on how this works?

Quote from: The Knowledge on April 06, 2012, 02:10:45 PM

Quote from: Tom Bishop on April 06, 2012, 01:10:52 PM

The moon cannot be seen across the disk to where you can see its side. It is only visible when it is over your present location. This is due to a combination of perspective and refraction. See Earth Not a Globe for additional information.

And you accuse me of talking rubbish? Say I'm in the UK, and someone else is in South Africa. It's night time. The Moon - a sphere according to you - is visible in the sky from both places. However, it's not directly overhead to either of us, and neither is it directly overhead to a third observer in Saudi Arabia. However, when we look at it we all see the same thing, despite your belief that it's only 3000 miles up above the surface and each observer is more than 3000 miles apart. Perhaps you might like to draw a triangle with the upper vertex representing the moon and the other two representing observers (or imagine a tetrahedron to include the third observer) and then explain how we are all able to see the exact same side of it, and furthermore, why we see that side and not any other, and why as it moves from east to west across the sky that view does not change.
Typing bollocks about perspective and refraction does not address the question,  neither do your links, neither is it explained anywhere in that well known fictional pamphlet Earth Not A Globe.

You are assuming that the light between the observers and the celestial bodies are traveling in straight lines. Light from the moon's face is bent to far off places, whereby light which is emanating from the moon's sides are lost to refraction entirely, which is why the moon is not at all times visible above the surface of the earth.

I asked you to address why light coming from one side of the Moon is "special" compared to light from other parts of the Moon. You didn't do that. You also neglect that when we look at the Moon, if it is a sphere, we are looking at light coming from the sides, just not perpendicular to its surface.
If light from, say, the crater Tycho is bent off in some direction, why is it also bent off in all other directions, thus enabling it to look the same everywhere? The concept of some sort of refractive effect, or whatever you think causes this, becomes entirely ludicrous when light has to be bent in many directions to make this work. How does a photon "decide" whether to be bent towards the UK, or South Africa, or Saudi Arabia?

The Knowledge is a worthless poster who does nothing but start trouble and spam the forum with nonsense.

By "start trouble" do you mean make threads you can't answer, and by "spam the forum with nonsense" do you mean write rubbish about light bending madly in every direction at once?

Quote from: Tom Bishop on April 06, 2012, 02:30:14 PM

You are assuming that the light between the observers and the celestial bodies are traveling in straight lines. Light from the moon's face is bent to far off places, whereby light which is emanating from the moon's sides are lost to refraction entirely, which is why the moon is not at all times visible above the surface of the earth.

Could we see a visual on how this works?

No, because it'd be impossible to draw.

No, because it'd be impossible to draw.

Nonetheless, it would be helpful to make an attempt at it.  All things can be represented somehow through drawings, if not completely accurately.

I'm curious to know, if Tom even knows how to demonstrate how light gets from a particular object to the eye, and what image will be produced from any angle.

I asked you to address why light coming from one side of the Moon is "special" compared to light from other parts of the Moon. You didn't do that.

It's special because the light from the side of the moon, traveling in a downwards horizontal direction, is traveling through more atmosphere to reach far off distant observers.

The light from the side of the moon does emit light downwards, not only to the side, you are correct. That is the light we see - the face of the moon.

You also neglect that when we look at the Moon, if it is a sphere, we are looking at light coming from the sides, just not perpendicular to its surface.

We are, and we see light from the side of the moon which are propagating downwards. The rays which are propagating sideways are lost to refraction. Hence, one does not see the side of the moon.

If light from, say, the crater Tycho is bent off in some direction, why is it also bent off in all other directions, thus enabling it to look the same everywhere?

The atmosphere is equally thick at two 3000 mile distant terrestrial points from the moon, hence the moon will be refracted to a similar degree.

The concept of some sort of refractive effect, or whatever you think causes this, becomes entirely ludicrous when light has to be bent in many directions to make this work.

The atmosphere is a gradient in all directions beneath the moon.

How does a photon "decide" whether to be bent towards the UK, or South Africa, or Saudi Arabia?

The thickness of the atmosphere it must pass through to reach the observer decides how much the light is bent.

It could be argued that refraction cannot cause this sort of bending, bringing up the straw in a drinking glass example. But in the straw-drinking-glass example is a small scale experiment. If the rays continued on their modified path over significant distance the image of the straw upon the water would be significantly displaced, and not just centimeters apart as seen in the straw experiment.

Sorry, the refractive effect only occurs during transitions between substances with different refractive indices, or densities. The amount of atmosphere it must travel through is irrelevant; only the rate of change in atmospheric density applies here, because the amount of refraction depends only on that. If you understand what a gradient is as you mentioned, then you understand that this can be simplified so that you do not even need vector calculus.

Sorry, the refractive effect only occurs during transitions between substances with different refractive indices, or densities. The amount of atmosphere it must travel through is irrelevant; only the rate of change in atmospheric density applies here, because the amount of refraction depends only on that. If you understand what a gradient is as you mentioned, then you understand that this can be simplified so that you do not even need vector calculus.

The length of atmosphere is relevant. If a photon is displaced by an angle of 0.02 angles at one place, it will continue traveling on that 0.02 displacement for the duration of its journey, becoming more and more displaced from the original path with distance.

If you sent a beam of light perfectly parallel across your flat earth at a constant altitude, it would stay straight. The index of refraction does not change, so the path does not change. This is a lot of atmosphere to travel through, yet there is no refraction because delta density if zero. Angular displacement is only due to a change in index of refraction.

Quote from: iconoclast on April 06, 2012, 08:16:23 PM

Sorry, the refractive effect only occurs during transitions between substances with different refractive indices, or densities. The amount of atmosphere it must travel through is irrelevant; only the rate of change in atmospheric density applies here, because the amount of refraction depends only on that. If you understand what a gradient is as you mentioned, then you understand that this can be simplified so that you do not even need vector calculus.

The length of atmosphere is relevant. If a photon is displaced by an angle of 0.02 angles at one place, it will continue traveling on that 0.02 displacement for the duration of its journey, becoming more and more displaced from the original path with distance.

There is more atmosphere, yes, but since the rate of change of refractive index is lower, the rate at which the light changes direction will also be proportionally lower.

Quote

How does a photon "decide" whether to be bent towards the UK, or South Africa, or Saudi Arabia?

The thickness of the atmosphere it must pass through to reach the observer decides how much the light is bent.

He was asking here about the direction the light bends in, and not the magnitude.

Quote from: Tom Bishop on April 06, 2012, 08:19:18 PM

Quote from: iconoclast on April 06, 2012, 08:16:23 PM

Sorry, the refractive effect only occurs during transitions between substances with different refractive indices, or densities. The amount of atmosphere it must travel through is irrelevant; only the rate of change in atmospheric density applies here, because the amount of refraction depends only on that. If you understand what a gradient is as you mentioned, then you understand that this can be simplified so that you do not even need vector calculus.

The length of atmosphere is relevant. If a photon is displaced by an angle of 0.02 angles at one place, it will continue traveling on that 0.02 displacement for the duration of its journey, becoming more and more displaced from the original path with distance.

There is more atmosphere, yes, but since the rate of change of refractive index is lower, the rate at which the light changes direction will also be proportionally lower.

Exactly

Last I checked, increasing refractive index caused light to bend into the medium.  This should cause downward bending, and not upward bending, which would be required for everyone who can see the moon to always see the bottom of the moon.

Quote from: The Knowledge on April 06, 2012, 04:43:47 PM

I asked you to address why light coming from one side of the Moon is "special" compared to light from other parts of the Moon. You didn't do that.

It's special because the light from the side of the moon, traveling in a downwards horizontal direction, is traveling through more atmosphere to reach far off distant observers.

The light from the side of the moon does emit light downwards, not only to the side, you are correct. That is the light we see - the face of the moon.

Quote

You also neglect that when we look at the Moon, if it is a sphere, we are looking at light coming from the sides, just not perpendicular to its surface.

We are, and we see light from the side of the moon which are propagating downwards. The rays which are propagating sideways are lost to refraction. Hence, one does not see the side of the moon.

Quote

If light from, say, the crater Tycho is bent off in some direction, why is it also bent off in all other directions, thus enabling it to look the same everywhere?

The atmosphere is equally thick at two 3000 mile distant terrestrial points from the moon, hence the moon will be refracted to a similar degree.

Quote

The concept of some sort of refractive effect, or whatever you think causes this, becomes entirely ludicrous when light has to be bent in many directions to make this work.

The atmosphere is a gradient in all directions beneath the moon.

Quote

How does a photon "decide" whether to be bent towards the UK, or South Africa, or Saudi Arabia?

The thickness of the atmosphere it must pass through to reach the observer decides how much the light is bent.

It could be argued that refraction cannot cause this sort of bending, bringing up the straw in a drinking glass example. But in the straw-drinking-glass example is a small scale experiment. If the rays continued on their modified path over significant distance the image of the straw upon the water would be significantly displaced, and not just centimeters apart as seen in the straw experiment.

This is nonsense. Try drawing a diagram of this, I think you'll find it impossible.

So with the infinite number of directions light shines from a sphere, we somehow only see one direction of light from a sphere only 3000 miles high (according to FE)

The light then hits the atmolayer (someone remind me, is the atmolayer 3000 miles deep?) and then somehow bends an infinite number of directions, not losing any significant intensity, and presents the viewer on the ground with a perfectly round sharply focused image.

Oh, and it re-sizes so it always looks the same size, while approaching faster from the horizon (in order to appear to rise at a noticable rate) and then traveling slower while more overhead, and speeding up again in order to appear to set at the same rate of movement (which TB tried to explain.  I'll have to find that post again.  It was interesting).

As for the re-sizing being attributed to phsycological tricks to the eye (looking bigger on the horizon due to buildings or whatever), I took these last night.  Probably should have posted them here anyway instead the other thread.

Just came up over the hills at 9:16


3 hrs later.

I think that's a wrap. The false refraction theory has been disproved completely.