61) “If the Earth were actually a big ball 25,000 miles in circumference, the horizon would be noticeably curved even at sea-level, and everything on or approaching the horizon would appear to tilt backwards slightly from your perspective. Distant buildings along the horizon would all look like leaning towers of Piza falling away from the observer. A hot-air balloon taking off then drifting steadily away from you, on a ball-Earth would slowly and constantly appear to lean back more and more the farther away it flew, the bottom of the basket coming gradually into view as the top of the balloon disappears from sight. In reality, however, buildings, balloons, trees, people, anything and everything at right angles to the ground/horizon remains so regardless the distance or height of the observer”

See the answers to point 60.

The principle of Dubay’s argument is correct; we would see towers leaning away a little, if we had built towers hundreds of miles high! Again, he doesn’t take the sheer size of the world into account.

Suppose  our viewpoint and the tower were high enough that we could see the building from thirty miles away.  The circumference of the earth is about 25,000 miles, so we can find the difference in angle between our position and that of the tower very easily.

It is 30/25000 * 360 degrees, which is 0.432 – less than half a degree.

Even at 100 miles  the building would appear to lean away by only 1.44 degrees. Could you see that a building was leaning back, directly away from you, by less than one and half degrees at a distance of 100 miles? No, and nor could I.

By the way, Mr Dubay says that tall buildings should look like the Leaning Tower of Pisa. Well, that tower currently leans  by 3.99 degrees (it was 4.5 degrees until they straightened it slightly in 1990).

 For the curvature of the earth to make a building lean by that much, it would have to be visible to us at a distance of 275 miles. 

Again, would anyone notice a small lean (directly away from us, not sideways on as the Tower of Pisa is usually shown) from that distance?

This is typical of one kind of mistake flat-earthers make in these arguments – they don’t do the mathematics, and often they don’t seem to understand it, either.