# Claim: footage of Great South Bay Bridge supports flat earth

Discussion in 'Flat Earth' started by Rory, Mar 23, 2019.

1. ### RorySenior Member

A flat earth YouTuber has been asking me to share his video here. I've told him that it wasn't really good enough quality - either as an image or a debunk - but he's basically begged me to post it, so, forgive me, I couldn't help but oblige.

What he has is a shot of the Great South Bay Bridge in New York taken with a P900:

He was standing at 40.732422, -72.866975, which is 21.5 miles away, at an elevation of about 20 feet.

Predicted hidden height is 139 feet, given standard refraction, and he tells me the bridge is 155 feet tall - seems right - meaning about 16 feet should be visible.

Here's a picture of the bridge in question:

For me, it's quite clearly at conflict with the flat earth notion, given that we can't see the lower portion of the bridge, the flat parts either side of the arch, or any sign of land.

I tried to do a Google Earth overlay, but for some reason I haven't been able to make that work lately.

Anyway, someone may have something to add.

So what's to debunk? It's showing what you'd expect to see on the globe with standard refraction.

Increasingly it seems they are going for "the Earth isn't round, it just looks like it is"

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3. ### deirdreModeratorStaff Member

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The model in Google Earth tops at 49m (160 feet) above the water.

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5. ### RorySenior Member

Yah, I know it's a low level 'claim' - but it may do him good to have it analysed here. Thanks for the input.

6. ### GerardMember

I looked at this guy's comments on the youtube video. It's clear he has some major misconceptions about how the geometry of vision works. Those misconceptions are probably more relevant to his FE theory than the exact results for this bridge.

He appears to believe that perspective (ie. projective geometry) can lead to occlusions of objects in the field of view, which is clearly not true.

For example he says:
Well, that's a very easy claim to test for anyone with access to a gym or other large room with a flat floor. Just identify (or create) a mark on the floor at the far wall then turn a smartphone upside down with the top resting on the floor (making sure it's not tilted) and take a picture. You should be able to see the mark. It will be very compressed longitudinally (that's the effect of perspective) but as long as the camera resolution is sufficient it should still be visible. For example if the mark is a line perpendicular to the wall it may appear as a very short rectangle against the far wall (be sure to use a mark with good contrast relative to the wall).

7. ### MendelMember

1) Gymnasium floors are not guaranteed to be flat. If they're curved, you will see curvature. We've been through this with football fields designed for drainage.

2) With typical floor undulations, perspective compression (foreshortening) should indeed make much of a level floor undiscernable if you rest your ear on the ground. I have seen other flat Earthers make this argument with respect to horizontal surfaces (where it is easily demonstrated), and then have them subsequently apply it to diagonal and vertical surfaces as well, where the necessary condition of a near-zero viewing angle (correct usage!) no longer holds. Placing the target on the wall makes it easier to see, and demonstrates the (absence of) vertical obstruction, which is what we're concerned about.

3) The tilt of the smartphone does not affect the result unless the tilt is so large that the mark is out of shot.

Last edited: Mar 25, 2019

The camera resolution probably isn't sufficient though, for a gymnasium. My garage floor is reasonably flat. Here's a sheet of yellow paper from about 30 feet:

And from about 0.5" above the ground

It's just visible.

Horizontal marks on the floor are a bit of a red herring though. Obviously they are hard to see, because they are small in the image, and for the reasons @Mendel mentioned. The issue here is if a vertical object becomes obscured from the bottom up on a flat plane. It certainly does not in my garage, and of course, optically it would not at any distance.

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9. ### GerardMember

You don't have great contrast there. I think a sheet of red construction paper would show up much more clearly.

10. ### deirdreModeratorStaff Member

if you had access to a large swimming pool and can convince the maintenance guy to turn off the filter for an hour.. you could float something tiny at the other end. Plus you could really get your waterproof camera down to water level, unlike eyes to a gymnasium floor.

Sure, but at some point, it's going to be sub-pixel, and most floors are not flat.

Like I said though - it's a red herring, a distraction. They like it because it is actually hard to see "the ground" a really long way away. But what we are interested in is mountains, buildings, and bridges - vertical things that actually get obscured by the curve

12. ### GerardMember

Yes, but if this is how they're "explaining" obstruction by the horizon it seems like it should be addressed.

I tried this experiment on a desktop with a piece of white tape at one end. At first it did seem very hard to see to the end of the desk because the tape blended in with the white wall behind it. I then colored the top of the tape black with a marker and found that the black mark could clearly be seen (with zooming), which proved that I could actually see to the edge of the surface, as geometry dictates.

I think a reasonable person would be able to extrapolate from this and conclude that a large truly flat surface cannot obstruct anything above it.

But then reasonable people don't believe that the earth is flat, so I'm not sure what can be done for the others.