This project is based on the experience of Eratosthenes, curator of the library of Alexandria, that 2200 years ago, calculated in a simple way, the circumference of the Earth by comparing two shadows.
The calculation requires partners situated all over the planet.
Nothing new: everybody should know, since two millennia that the result is 40 000 km
The interest is the combination of a very simple experiment with ICT and web 2.0 tools
