Lecture 39: The Fate of the Universe

What is the ultimate fate of the Universe? The ultimate fate of the Big Bang is either expansion to a maximum size followed by re-collapse (the Big Crunch) or eternal expansion into a cold, dark, disordered state (the Big Chill). Which of these is our future depends on the current density of matter and energy in the Universe, Omega0. This lecture examines our current knowledge of the matter and energy content of the Universe, which leads to the surprising discovery that we live in a Universe that is Flat (Omega0=1), Infinite, and Accelerating! We will end the lecture by exploring the possible fate of an infinite accelerating Universe. Recorded 2006 March 2 in 1008 Evans Laboratory on the Columbus campus of The Ohio State University.