The Cosmic Distance Ladder

Professor Terence Tao, Fields medal winner, answers the question: How do we know the distances from the earth to the sun and moon, from the sun to the other planets, and from the sun to other stars and distant galaxies?  In this talk, he presents some methods of measurement that all use a "cosmic distance ladder" to get convincing and accurate results without the need for advanced technology.

Among Tao's other awards are the Bôcher Prize, the SASTRA Ramanujan Prize, the Clay Research Award, the Nemmers Prize, and, in 2010, he shared the Pólya Prize with Emmanuel Candès of Stanford.