Dear All, I am confused. What is the circumference of the Earth, or is this a question that is too hard to answer?
My research found: Erastothenes apparently calculated an Earth circumference (in SI units) of 39�350�kilometres based on a distance between Syene and Alexandria of 787 kilometres. This circumference implies a diameter of 12�525�kilometres. The founders of the first metric system assumed a circumference of exactly 40�000�kilometres and this suggests a diameter of 12�732.4�kilometres. Heimler, Neil. Principles of Science (Merrill, 1992) gives a diameter of 12 756 km , which gives a circumference of 40 074 kilometres. World Book Encyclopedia (World Book) gives a diameter of 12 713 km , which gives a circumference of 39 939.067 kilometres Encarta (Microsoft 1996) gives a diameter of 12 765.3 km, which gives a circumference of 40 075 kilometres. Earth, Space and Time: An Introduction to Earth Science. (New York: Wiley, 1979) gives a diameter of 12 752 km, which gives a circumference of 40 062 kilometres. Infoplease.com says that the equatorial diameter is 12 760 km and the polar diameter is 12 720 km, so taking a simple average of these two I get a diameter of 12 740 km, which gives a circumference of 40 087 kilometres. Is it any wonder that I'm confused. Can anyone help me? Cheers, Pat Naughtin Geelong, Australia --
