Ok I am new to this site and I am intrigued with both sides of the argument. I am pretty open-minded until I get all the facts. I have one question that came to mind while reading some other threads.
My question is: If one were to aim a powerful telescope directly at the horizon to see the end of the earth, why would he not be able to do so? Also related to this is, why are ships on the ocean unable to see each other past a certain point (i.e. when land is invisible even by telescopes until reaching close enough proximity)?

Thanks!
I have asked the same question .
It's a little early for you to expect a reply from FE's , but here is the usual reply.:
1. It is a matter of perspective and the human eye is limited in how far it can see. And also :The distance would be so great that the objects would be too small for the human eye to see. They also claim that you can not see because of the swells in the sea.
And the "Round Ocean" as you have shown on your diagram "would be like looking through a wall of water."
2.The distance you can see is limited by the thickness of the atmosphere. (They call it the atmolayer.)
Your diagram is based on a " round earth ", which of course is incorrect to the FE.
Be advised also that FE's also say that if a ship disappears over the horizon, you can "restore it" and see the whole ship again with a telescope. Supposedly - as one FE has stated - "This works on land, too", so you should be able to see land with a telescope after it has disappeared over the horizon, too.
It will be interesting to see the FE replies. I think this has been covered on other threads though. I shouldn't have intervened and left it to the FES, but I thought it might be interesting to see how FE replies compared to what I have seen on previous threads.