What was the Universe like from the earliest phases immediately after

the Big Bang to the present day? This lecture reviews the physics of

matter, and follows the evolution of the expanding Universe from the

first instants after the Big Bang, when all 4 forces of nature were

unified in a single grand-unified superforce until the emergence of the

visible Universe we see around us today. Recorded 2006 March 1 in 1008

Evans Laboratory on the Columbus campus of The Ohio State University.