Using only the sunlight striking the Earth and a wooden dowel, students can measure the circumference of the
earth. Eratosthenes did it over 2,000 years ago. In Cosmos, Carl Sagan shared the process by which
Eratosthenes measured the angle of the shadow cast at local noon when sunlight strikes a stick positioned
perpendicular to the ground. By comparing his measurement to another made a distance away, Eratosthenes
was able to calculate the circumference of the earth.
This project meets standards for Math, Science, Reading and Geography.
Students receive buttons for each activity.