John C. Mather delivered his Nobel Lecture 8 December 2006, at Aula Magna, Stockholm University, where he was introduced by Professor Per Carlson, Chairman of the Nobel Committee for Physics.

Summary: The story of the COBE satellite mission began in 1974. The successful launch in 1989 was a landmark for modern cosmology. The spectrum of the cosmic microwave background radiation was shown to follow very precisely a black body form with a temperature of 2.725 K, giving strong support for the Big Bang theory of the Universe.