Sciencecamps

On the 20th June a group of students in Cork linked through YST with a group of students in dar es Salaam. Using Skype the students repeated the famous experiment of Eratosthenes!

When did people first realize that the earth might be round rather than flat? What evidence did they use? By the third century BC the scholars of that time believed that the earth was a sphere. One empirical piece of evidence is observing ships as they approach the horizon. The sails appear to dip into the ocean. But no one knew for sure how big this sphere was. It took a curious & ingenious librarian named Eratosthenes to discover a remarkably simple method for measuring the circumference of the earth.

Over 2,000 years ago Eratosthenes made a remarkably accurate measurement of the earth's circumference. This project requires collaboration of students in places at different latitudes of the earth to make some simple measurements, share data, use a spreadsheet to make comparisons, and then replicate and share their results. Here is a summary of the steps involved in making the measurements:

At least two sites must collaborate whose latitudes (north-south distance) are different enough to give a significant difference in measurements. 2. On the given date students will conduct their measurements outdoor at high noon, local time.

This data along with the latitude for each site is enough information to use a simple proportion to make a fairly accurate calculation of the Earth's circumference as determined by each pair of sites.