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How to measure Earth in 10 minutes

About This Course

Eratosthenes of Cyrene was a Greek mathematician, geographer, poet, astronomer, and music theorist. He was a man of learning, becoming the chief librarian at the Library of Alexandria. He invented the discipline of geography, including the terminology used today. He is best known for being the first person to calculate the circumference of the Earth, which he did by applying a measuring system using stadia, a standard unit of measure during that time period. His calculation was remarkably accurate.

In the course we follow the steps that Eratosthenes did in his times and we will try to measure the circumference of the Earth by ourselves.

Eratosthenes's only tools were sticks, eyes, feet and brains; plus a zest for experiment. With those tools he correctly deduced the circumference of the Earth, to high precision, with an error of only a few percent. That's pretty good figuring for 2200 years ago. - Carl Sagan -


When participating in this course you need to have knowledge about basic geography and math.

Course Staff

Kerri Gertrud Vestberg

Daniela Bellomonte

Laura Gambino

Vida Zviniene

Eugenia Kypriotis

Ramune Selickaite