Downvoted, but valid. I would claim that Ugg’s effort counts as a lower bound on the size of the Earth, and is therefore a legitimate constraint on true measur

Downvoted, but valid. I would claim that Ugg’s effort counts as a lower bound on the size of the Earth, and is therefore a legitimate constraint on true measurement. This bound might even be sufficient for some purposes. It also seems like ancient mariners should have been able to use the visible arc of the horizon to get a rough guess, long before Eratosthenes. All we are really arguing about is, how good are the error bars?