2006-07-08 02:50:21 · 3 answers · asked by Woods Of The World 2 in Education & Reference ➔ Other - Education
You don't have to leave the Earth. The ancient Greeks knew the Earth was round, and probably the Chinese as well. If you have a clear view flat to the horizon (like an ocean), any object coming to you over the horizon will appear from the top down, meaning the Earth must be round. To see the whole Earth as a round ball, you have to be quite a ways up past the atmosphere. The atmosphere is actually quite thin.
http://earthobservatory.nasa.gov/Study/EdLu/
2006-07-08 02:59:20 · answer #1 · answered by thylawyer 7 · 1⤊ 0⤋
A half mile or so you can see the curve of the horizon. If you want to see the whole sphere hitch a ride on the space shuttle.
2006-07-08 09:57:19 · answer #2 · answered by Anonymous · 0⤊ 0⤋
At least 40,000 feet
2006-07-08 09:56:31 · answer #3 · answered by mapleguy 7 · 0⤊ 0⤋