Great Moments In Science: Forgetting the earth is round

It may surprise you, or may not, that in the middle ages we forgot a lot of information. A tonn used to be stored in the great library of Alexandra and a lot was lost in the dark ages. Im not an expert on what exactly was and was not known but one good example is the roundness of the earth. Ancient greeks and romans realized the earth was round over 2000 years ago. One of them measured it with a sick, it's quite a good story. Anyway he estimated the circumference to be 250 000 stades. Depending on your definition of a stade that's within 2% to 20% of the correct value of 40 008km. Hmm 40 008 seems like a veryround number, why the extra 8. Well the meter was at one point was defined as:

1791 March 30 — The French National Assembly accepts the proposal by the French Academy of Sciences that the new definition for the meter is equal to one ten-millionth of the length of the Earth's meridian along a quadrant through Paris, that is the distance from the equator to the north pole. (wikipedia)

Well now the definition is a more sensable "distance traveled by light in vacuum during a time interval of 1/299 792 458 of a second", wow glad they got that cleared up. Anyway something may have been lost in the translation as there have been several different standards in the intervening years. Also It's hard to tell how accurately they could have measured the equator to north pole distance in 1791, hence the 8 km error.