When studying monuments like Stonehenge it becomes clear (or at least seems probable) that the ancients knew what the size of the earth was.
This becomes even more evident when reading books like these
But how did they figure it out?
And why hasn't anyone ever seriously tried to answer that question? Or even ask it?
Did they think it was impossible or unlikely?
Well, it seems it wasn't. In fact it's quite easy. All you need is a lot of time and some manpower (or was it the other way around?).
But let's not spoil the surprise by just telling you outright. Let's see if you can find out for yourself how the earth was measured some 3000 years B.C.
So let's suppose it's 3000 B.C.
You are in England.
You have no boat.
You want to know the size of the planet you're on.
Where do you start?