Since sept 2000, thousands pupils in intermediate course have measured the Earth's circumference from their classroom, simply by observing the shadow of a vertical stick at noon local solar time. Again this year, schools of many countries will join together to reproduce the observations of the Greek scientist who, more than 2000 years ago, was the first to propose a simple method to measure our planet's size.
Following in his wake, the pupils will learn how to observe the shadows and the motion of the Sun in the sky and they will build their own measuring instruments, all through the year and the 5 sequences that we propose you. Thus, by measuring the shadow of a vertical stick at noon local solar time and by exchanging their results with other schools through Internet, they will be able to compute the Earth's size in their turn.
To come with you session after session, a network of scientists and pedagogues with expertise in astronomy will be placed at your disposal to answer all your questions and to help you to bring the proposed activities into play. During this project, you will work in collaboration with many schools in Europe and abroad; you will share and compare your results thanks to Internet.
Finally, on June the 21rst, we will go back in time virtually proceeding up the Nile from Alexandria to Syene (now Aswan), where Egyptian schools are waiting for us. Together, we will then reproduce the live historical experiment which permitted Eratosthenes to measure the size of the Earth more than 20 centuries ago!