Lecture 34: The Expanding Universe
How did we discover that the Universe is Expanding? What does\nit mean that it is expanding? This lecture introduces Hubble's Law,\nthe observational evidence that the Universe is systematically\nexpanding. As galaxies get more distant from us, the apparent speed\nof recession gets larger in proportion. The proportionality is the\nrate of expansion, called the Hubble Parameter (H0). This leads us\nto the idea of expanding space, and the Cosmological Redshift, which\ncombined with the Hubble Law allows us a way to estimate very large\ncosmic distances. We will take up the more thorny issue of the\nCosmic Distance Scale in tomorrow's lecture.\nRecorded 2006 February 23 in 1008 Evans Laboratory on the Columbus campus\nof The Ohio State University.