In the mid-20th century, scientists began launching satellites into space that would help determine the exact circumference of the Earth. But over 2,000 years earlier, a man in Ancient Greece came up with nearly the exact same figure using just a stick and his brain.

Science Insider tells you all you need to know about science: space, medicine, biotech, physiology, and more.

Subscribe to our channel and visit us at: http://www.businessinsider.com/science
Science Insider on Facebook:   / businessinsiderscience  
Science Insider on Instagram:   / science_insider  
Business Insider on Twitter:   / businessinsider  
Tech Insider on Twitter:   / techinsider