I don't know that I am; you were the one to bring up the implicit “light travels in straight lines” assumption with your claim about ants on a flat table. I wo

I don't know that I am; you were the one to bring up the implicit “light travels in straight lines” assumption with your claim about ants on a flat table. I would argue that it was implied before I first commented. Without any assumption about the way light moves, you can not answer visibility questions on spheres and desks. The first comment talked about a spherical earth and certainly assumed light behaves as commonly accepted, the response did not question this either. Only after it has been pointed out that the response was not valid, the behavior of light entered the discussion. It depends how much distance you give the light. Shadows are noticeably blurry if your hand is close to the light source. Use a point light source or account for the size and shape of your light source. You're never going to get a situation where the air temperature is consistent enough for this; it varies by height (as does pressure). And, again, unless you can show me that “index of refraction” is a thing that applies to air, I'm not going to believe something as ludicrous as Snell's Law. (After all, isn't the speed of light a constant? The whole derivation rests on the assumption that it varies depending on the medium!) Make up your mind. Does light move in straight lines or doesn't it? Does a medium influence light traveling through it or doesn't it? If, how? You questioned light moving in straight line, it is beyond me why you would now also question light moving not in straight lines. Or is it just the mechanism that you are questioning? And nobody claims the speed of light is constant, the speed of light in vacuum is constant. And in order to cut this cat and mouse game short, just present your complete theory of how the world works upfront. There is no point in such a discussion if you keep changing what you believe or say every time an issue is pointed out.