How would "Bendy Light" even work on a Flat Earth?

Enricks

Member
On the Flat Earth model you would never see the horizon, as it's too far away. The existence of a horizon like we see here requires either some strange bendy light and/or a gross misunderstanding of perspective.

In fact the simply observations of the sharp horizon seen in this thread, together with the observation that the horizon recedes as you get higher, should be sufficient to demonstrate the curvature of the ocean.

What do you mean by "bendy light"?

Mick West

Staff member
What do you mean by "bendy light"?
Light that bends in a way unknown to modern physics.

There are various observations that only work on the globe earth - like the position of stars (Polaris being the easiest example), and things like the sun setting, or ships dropping below the horizon. These thing prove that the Earth is a globe unless light is bending in a bizarre way that makes it only appear to be a globe.

And while you can possibly explain one of these observations as being bending light on a flat disk, you can't explain them all. You could concoct a weird set of light paths that work for observations of polaris from anywhere on the disk, but that would not explain the dip of the horizon, or the paths of the southern stars.

The term "bendy light" is a slightly humorous reference to the bizarre convolutions that light would have to go through to fit real-world observations like sunsets on the imaginary world of a flat disk. The term "bendy" is used instead of simply "bent" or "bending" to distinguish it for the minor bends of light paths we see from refraction - usually only degree or two at most near the horizon, and very little elsewhere.

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Enricks

Member
Light that bends in a way unknown to modern physics.

There are various observations that only work on the globe earth - like the position of stars (Polaris being the easiest example), and things like the sun setting, or ships dropping below the horizon. These thing prove that the Earth is a globe unless light is bending in a bizarre way that makes it only appear to be a globe.

And while you can possibly explain one of these observations as being bending light on a flat disk, you can't explain them all. You could concoct a weird set of light paths that work for observations of polaris from anywhere on the disk, but that would not explain the dip of the horizon, or the paths of the southern stars.

The term "bendy light" is a slightly humorous reference to the bizarre convolutions that light would have to go through to fit real-world observations like sunsets on the imaginary world of a flat disk. The term "bendy" is used instead of simply "bent" or "bending" to distinguish it for the minor bends of light paths we see from refraction - usually only degree or two at most near the horizon, and very little elsewhere.

Ah, I see. But I don't think a strange light path could possibly alter the position of polaris in the sky, so that you will seem to be standing on a globe. And even then, there's also all the other star in the sky following a very clear path (that is, not distorted or deformed, unless close to the horizon because of refraction), depending on your latitude.

You said "it would not explain the dip of the horizon". By that, you mean that a SINGLE weird set of light paths wouldn't explain ALL the observation in the real world? Basically you'd have to live in a world where light bends in a certain way for seeing a ship dropping below the horizon (or the sun setting), and in another world with another strange light path to be seeing the horizon dip.
Or you meant that the dip of the horizon can't be explained in any way, even with a strange bending of the light? Just like the path of the southern stars.

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Mick West

Staff member
Ah, I see. But I don't think a strange light path could possibly alter the position of polaris in the sky, so that you will seem to be standing on a globe.
a strange series of light paths could though. Depending on where the hypothetical polaris is you can draw a set of curved light paths from it so that they impact the surface of the earth at the correct angle to simulate the globe model.

Of course the simpler explanation is just that we are on a globe, and light travels in straight lines.

You said "it would not explain the dip of the horizon". By that, you mean that a SINGLE weird set of light paths wouldn't explain ALL the observation in the real world? Basically you'd have to live in a world where light bends in a certain way for seeing a ship dropping below the horizon (or the sun setting), and in another world with another strange light path to be seeing the horizon dip.

Exactly. And with something like the sun setting you've got the additional problem that ships get smaller as they get further away, but the sun does not. There's no model in which you can get it to work as a flat plane.

Enricks

Member
a strange series of light paths could though. Depending on where the hypothetical polaris is you can draw a set of curved light paths from it so that they impact the surface of the earth at the correct angle to simulate the globe model.

Of course the simpler explanation is just that we are on a globe, and light travels in straight lines.

That light travels in straight lines is also really simple to see and test. I don't think a FE would go as far as suggesting that light goes crazy in some strange way. To explain ships and the sun setting I have seen them arguing just about perspective (that is, their own creative misconceived version of perspective).

But then again, I don't think the southern stars paths could be explained in any other way than we are on a globe, not even with some utterly strange light paths.

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Amber Robot

Active Member
That light travels in straight lines is also really simple to see and test. I don't think a FE would go as far as suggesting that light goes crazy in some strange way. To explain ships and the sun setting I have seen them arguing just about perspective (that is, their own creative misconceived version of perspective).

Perspective can't explain the setting sun. Period. If you tried to explain the setting sun by bendy light, you'd have to explain why the horizon remains where it supposed to be, but a light path infinitesimally above the line of sight to the horizon actually goes up into the sky and goes toward the Sun. I can't imagine how one would make that work.

Mick West

Staff member
I can't imagine how one would make that work.

It's quite a mind bender trying to even force ONE phenomenon (like the the setting sun) into a Bendy Light model, let alone all of them.

Consider we know how (i.e. at what angle) the sun's rays hit the surface of the earth at every point, so we could, in theory, take that info and translate it onto a Gleason map (azimuthal equidistant). Take an equinox for simplicity. We know the the angles work like this (Earth Viewed from the side, sun 93 million miles off to the right)

Then if we "unwrap" this into a flat plane you can see how the light kind of must be curving to create the effect.

You could extend it even more.

Of course the light does not have to exactly follow THESE curves, as the only requirement is that it arrive at the surface at a particular angle.

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Whitebeard

Senior Member.
Light CAN bend due to gravitational lensing. However to get this effect you need very large and very distant objects like galaxies. Considering most flat earthers claim that a) gravity doesn't exist and b) space doesn't exist and stars etcetera are lights on the dome that covers the disc, it leaves a few conundrums that really do need fractured logic explain if 'bendy light' is needed to explain the horizon issue.

Henk001

Senior Member.
The funny thing is that all "where is the curve" claims about objects that should be behind the horizon only make sense (neglecting all kinds of errors) if you accept that light goes in a straight line.

Enricks

Member
but a light path infinitesimally above the line of sight to the horizon actually goes up into the sky and goes toward the Sun.

You mean like this? (even though it's the moon in this case)

Mick, about Polaris: if you have to bend light paths in a certain way to fit a certain angle at a certain latitude, then for all other latitudes you would be out.
Like you said before, one weird set of light paths would only solve a problem, not ALL of them. You'd basically need light to magically bend in a way in one place and in another way in another place (and so on) for Polaris to be in the right place for every location at every latitude. But that's not clearly possible: even if you create a "Bendy Light model", light must always travel like that, hence the "And while you can possibly explain one of these observations as being bending light on a flat disk, you can't explain them all".

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Amber Robot

Active Member
You mean like this? (even though it's the moon in this case)

No, that's nothing like what I'm thinking.

Enricks

Member
No, that's nothing like what I'm thinking.

Could you draw a scheme?

Hevach

Senior Member.
Light CAN bend due to gravitational lensing. However to get this effect you need very large and very distant objects like galaxies. Considering most flat earthers claim that a) gravity doesn't exist and b) space doesn't exist and stars etcetera are lights on the dome that covers the disc, it leaves a few conundrums that really do need fractured logic explain if 'bendy light' is needed to explain the horizon issue.
Some flat earth explanations involve Electric Universe borrowed bunk to cover this, however light cannot bend due to magnetic fields. The strongest field created in a laboratory is 914,000 gauss, 1.4 million times as strong as Earth's (0.65 gauss at the strongest). The most powerful field observed to date is a magnetar estimated to have a field strength of 1 quadrillion (1,000,000,000,000,000) gauss. Even at this strength, no lensing has been detected. None is expected but they check that stuff anyway because in science, the best way to get famous is to contradict a core theorem of your field. Even if you're wrong, everybody knows your name and as long as you admit you screwed up and account for the error, there's no stigma of being wrong in science.

Amber Robot

Active Member
Could you draw a scheme?

I don't have time to draw anything right now, but think of it this way. On the flat Earth, when you're looking at the horizon you are looking at basically 0 degrees from horizontal and seeing things that are essentially 0 feet above the surface of the Earth. When you're looking at the sunset, and the sun is at the horizon, you're seeing something that is 3000 miles above the surface of the Earth. Given the finite size of the flat earth and that the sun is supposed to be above the equator plus/minus the distance to the tropics the angle to the Sun cannot be 0 degrees from horizontal. So, if we're saying that light is bending from the sun down to the ground and lining up with light coming from the surface, how does that work? There's an infinitesimal difference in angle between the light coming from the parts of the earth's surface lying on the horizon and light coming the Sun, which does not really get close to the horizon in the flat earth model. If there's that much bending of light going on near the surface of the earth, I'm betting a lot of stuff would look weird, like mountains or tall buildings near the horizon, etc. If I get time I'll try to draw it.

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