[RhesusVX]

It shows how refraction can fool people into thinking the horizon curves downwards thus making them believe the world is a globe.

But the video does not appear to take into account Electromagnetic Acceleration so is not representative of a flat Earth.  What you are showing there is a flat Earth design that's almost certainly using round Earth physics with an unknown refraction coefficient used to make it look like the photo.  In reality the photo is a combination of two things - a bit of refraction and some curvature.

Besides, refraction can also increase the apparent viewing distance on a curved surface as light tracks along the ground for many miles further than it would do otherwise, fooling people into thinking that the world is a flat plane.  Like I said, it cuts both ways so refraction alone as a phenomenon doesn't actually demonstrate anything about the shape of the Earth.  If nothing else it just serves to add ambiguity!

As stack said in an earlier response, sometimes atmospheric refraction can be severe, sometimes moderate and sometimes non-existent.  In all cases, when it comes to viewing a ship going out to see, regardless of conditions you always see the ships hull disappearing first.  When you approach an island from out at sea that has a tall mountain/volcano on it, you always see the top of the mountain/volcano first.  I'll also refer you back to the Rainy Lake experiment I linked to in an earlier comment in this thread - that experiment is carried out over several miles over a frozen lake bed, with target heights to reduce the effect of refraction as much as possible while still being easy to work with.  The result?  What they see in the real world pretty much matches what they would expect to see based on a known surface radius with minimal refraction.  Take a look, it's an interesting read and a very thorough experiment.

[WTF_Seriously]

This video shows what happens when refraction is added to a scene in Cinema 4D. It might be of use to you perhaps.

https://youtu.be/1XoFnXX4UOI

What use is the video meant to be?  All it does is show that refraction can, depending on extent (which is unknown in that video) make it appear as though something in the distance is shorter than you'd expect, or even not visible at all.  In of itself it shows nothing about the shape of the Earth, only the possible effect of atmospheric refraction which is basically the same process in both models.  Maybe a curved surface alone would not be enough to create the pronounced effect as shown in some of the images earlier, but it would certainly compound the effect of refraction.

It shows how refraction can fool people into thinking the horizon curves downwards thus making them believe the world is a globe.

At what height from the earth's surface would refraction be negligible in a straight line of sight observation?

[WTF_Seriously]

For as long as I can remember I have always known the Earth is round, when I was a kid I went on a boat and saw the coastline disappear bottom first, as you would expect from a round object. I've always wondered since knowing about the FES how people could believe the Earth is flat, but that's my personal experience. How did you come to believe that the Earth was flat? I really want to know.

This video shows what happens when refraction is added to a scene in Cinema 4D. It might be of use to you perhaps.

I'll admit I'm no professor of optics, but doesn't atmospheric refraction cause light to bend toward the earth?  As such, aren't these WIKI statement true?

"Terrestrial refraction usually causes terrestrial objects to appear higher than they actually are,"

"A simple approximation is to consider that a mountain's apparent altitude at your eye (in degrees) will exceed its true altitude by its distance in kilometers divided by 1500. "

https://en.wikipedia.org/wiki/Atmospheric_refraction#Terrestrial_refraction

So the video is incorrect.  Adding refraction would cause each subsequent bridge tower to appear taller with the ground plane remaining straight.

[Tom Bishop]

Refraction can cause light to bend upwards or downwards.

[WTF_Seriously]

Refraction can cause light to bend upwards or downwards.

That proves absolutely nothing.  The only way the red line can be drawn to try to reference refraction is if it can be drawn in a zero refraction condition which it can't.  The video maker selectively chose to draw the red line at a point in time when refraction was greater than the refraction which caused the lights to appear to "move up".  I can take that video and draw the same red line (well, I can't personally because I'm no videographer) at a different time in the video and all of the lights will appear to only move down.

Edited to add:  That's not to say that refraction can't cause upward bending of light but what is usually witnessed is refraction causing light to bend downward.

[qistheearthflat]

If the Earth really is flat, then do you believe that gravity exists?
If you accept the most popular flat-earther theory that I've heard of-that gravity does not exist, and the earth is accelerating up at 32 feet per second, then why do a piece of paper and a book fall downward at different rates?
In the round earth theory, it's due to air resistance. However, if it's the earth that is accelerating upwards at a uniform speed then why do the two objects reach the ground at different times.

If gravity does exist, then as I move away from the centre of the earth,  the round disk will pull me to the 'left' of the disk, if say I am moving towards the 'right' of the round disk as there is move matter on the left than on the right in relation to my right-moving body, right?

[Pete Svarrior]

If you accept the most popular flat-earther theory that I've heard of-that gravity does not exist, and the earth is accelerating up at 32 feet per second, then why do a piece of paper and a book fall downward at different rates?
In the round earth theory, it's due to air resistance. However, if it's the earth that is accelerating upwards at a uniform speed then why do the two objects reach the ground at different times.

The reasoning is largely equivalent, though using the name "drag" is more intuitive than "air resistance". The air is moving upward, being pushed by the Earth, and thus inflicts drag on both bodies.

Keep in mind that, given that motion is relative, it would be impossible to locally distinguish between the FE model of Universal Acceleration and the RE gravitational model. This isn't a statement in support of either model, but rather just a consequence of physics.

[Tumeni]

Refraction can cause light to bend upwards or downwards.

The Bedford Canal experiments appear to presume a total lack of refraction. Do you agree?

https://wiki.tfes.org/Experimental_Evidence#The_Bedford_Canal_Experiments

The assertion is that lines AB and CD are parallel, with the vertical flags connecting these lines at right angles to them both, creating a series of perfect rectangles along the canal. Yes? No?

[qistheearthflat]

If the earth really is rising up, then are celestial bodies like the sun, stars, moon etc also rising up? And how do they orbit?  Do they complete something like an arc above the disk earth?

[JHelzer]

If the earth really is rising up, then are celestial bodies like the sun, stars, moon etc also rising up?

Yes. They must be. The earth, sun, moon & stars are all affected by the universal  attractor so they all accelerate together.