Eratosthenes

Eratosthenes of Cyrene, c. 276 BC c. 195 BC, was a Greek polymath. I regard him as the first true Physicist for his Gedankenexperiment to measure Earth's radius from a projected shadow, as I describe in my overview of Physics.

Eratosthenes.jpg

He was a contemporary of another great figure of Science: Archimedes.