Just as a boring FYI on the whole 'Earth is round vs flat thing'
Eratosthenes was I believe the first known person to calculate the circumference of the world in around 200bc
Pythagoras I believe mentioned the idea the world was round even earlier and with the context that implied the idea had already been around a while.
Aristarchus I believe, just a tad earlier than Eratosthenes but I could be wrong on this, was the first to put forward the idea the Earth orbited the sun, etc.
So basically a bunch of really smart mathematicians and astronomers (can there be any other kind?) worked out all this stuff pretty accurately ages ago, but the knowledge got buried and forgotten due to suppression.
I can't help wondering where we'd all be now if knowledge and advancement had continued unimpeded since that time without all the turmoil in between.
I've also wondered what is was in the water back in ancient Greece, etc. that made all those fellows so damn clever!
Final point - it's probably a fair assumption that some bright sailor must have wondered at the curved horizon, changing angle of view, the fact the moon looked like a sphere, etc. during their travels and thought... maybe it's round.
Try to be reasonable... its easier than you think...
