This quick TED talk entry is courtesy of TED.com. Adam Savage walks through two spectacular examples of profound scientific discoveries that came from simple, creative methods anyone could have followed — Eratosthenes’ calculation of the Earth’s circumference around 200 BC and Hippolyte Fizeau’s measurement of the speed of light in 1849. Find more TED-Ed videos on our new YouTube channel: youtube.com/TEDEd.