7. Cosmology Lecture 7 (February 25, 2013‪)‬ Modern Physics: Cosmology (Winter 2013)

Leonard Susskind examines the temperature history of our universe. The universe switched from radiation-dominated to matter-dominated when it was about one million times hotter than it is today, and the matter and energy decoupled from each other and the universe became transparent when it was about one thousand times hotter that it is today. (February 25, 2013)