‏@Al-Biruni: The Man Who Measured the Earth From a Mountaintop

A thousand years ago, a scholar climbed a mountain in India, looked at the horizon, and with simple mathematics measured the size of the whole Earth, coming within about one percent. That scholar was al-Biruni. He learned the language of India to understand its people as they were, and measured the density of gems with a precision close to our modern instruments. It is said he asked a scholarly question on his deathbed. In this episode we meet al-Biruni, and three of his achievements still present in science today.