So, in response to pictures and videos showing a distant tall building over water occluded by the curve of the earth, the claim is the building is actually obscured by waves.
The old "a dime can obscure an elephant" argument, example of the reasoning here:
Since the horizon is always at eye level, any imperfection on the horizon will therefore be above the level of the eye, and create an area where something larger can shrink behind it from the bottom up. It does not matter if that mass is very small, because as I have said, it is possible for a dime to obscure an elephant. The object need only get far enough behind it to become obscured
OK. Firstly, the horizon DOES NOT RISE TO EYE LEVEL.
I don't know why this lie is repeated so often. The simplest diagram will demonstrate that is not true.
Whether the earth is a sphere or flat, in either case the horizon will be BELOW eye level, the person is looking slightly downwards:
The confusion here is that the horizon is very close to eye level. This graph shows that even at an altitude of 20 miles, far higher than any normal human experience, the dip is only about 6 degrees:
https://www.desmos.com/calculator/vhmcatpgudBut there IS a dip and the dip is measurable with the right equipment. If flat earthers are so bothered about empiricism, as they claim, why don't they test this?
Anyway. Waves. Let's assume that the waves are around a meter high and your eye level is nearer 2 meters. You can see in this diagram that because you can see over the waves the only part of the building which would be obscured is just under a meter by the farthest wave:
And note that this is the worst cast scenario, in real life buildings are not built on the beach, the building would be some meters above sea level and not obscured at all by waves on a flat earth.
If the wave was as high as eye level then then the amount of building occluded would be the height of eye level.
Note that as this is a straight line it doesn't matter which wave is as high as eye level.
But what if the wave is higher than eye level? Here it would occlude more of the building:
And here it DOES matter which wave is higher than eye level, the closer the high wave the more of the building occluded:
This is where Tom's claim gets a bit ridiculous because he says:
"any imperfection
on the horizon will therefore be above the level of the eye, and create an area where something larger can shrink behind it from the bottom up[/quote]
My empahsis. So he's claiming there that it's waves on the horizon which can obscure buildings. Although I've seen him elsewhere claim that the horizon is the vanishing point where perspective lines meet so by definition you couldn't see anything beyond that anyway.
So, in brief it's actually waves
closer to you that could obscure distant buildings. But they can only obscure more of the building than their own height if they are higher than your eye level. So if you're a few meters above sea level it can't be waves obscuring the buildings unless the waves are higher than that which, across a narrow channel, they are unlikely to be.
The infamous Bishop experiment:
"On a very clear and chilly day it is possible to see Lighthouse Beach from Lovers Point and vice versa. With a good telescope, laying down on the stomach at the edge of the shore on the Lovers Point beach 20 inches above the sea level it is possible to see people at the waters edge on the adjacent beach 23 miles away near the lighthouse. The entire beach is visible down to the water splashing upon the shore"
For this to be true even on a flat earth it would mean no wave of over 20 inches high over a 23 mile stretch of sea. I'd suggest that is implausible, especially as he claims to be able to repeat this at any time in any conditions.