Sean M. Carroll of CalTech discusses how the direction of the arrow of time was defined by the Big Bang. He also speculates about what might have come before the Big Bang. The lecture is entitled The Origin of the Universe & the Arrow of Time.
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The evidence that the universe emerged 14 billion years ago from an event called ‘the big bang’ is overwhelming. Yet the cause of this event remains deeply mysterious. In the conventional picture, the ‘initial singularity’ is unexplained. It is simply assumed that the universe somehow sprang into existence full of ‘inflationary’ energy, blowing up the universe into the large, smooth state we observe today. While this picture is in excellent agreement with current observations, it is both contrived and incomplete, leading us to suspect that it is not the final word. In this lecture, the standard inflationary picture will be contrasted with a new view of the initial singularity suggested by string and M-theory, in which the bang is a far more normal, albeit violent, event which occurred in a pre-existing universe. According to the new picture, a cyclical model of the universe becomes feasible in which one bang is followed by another, in a potentially endless series of cosmic cycles. The presentation will also review exciting recent theoretical developments and forthcoming observational tests which could distinguish between the rival inflationary and cyclical hypotheses.
Gerard t’Hooft, a Nobel Laureate from Utrecht University, delivers a lecture on Science Fiction and Reality at the Perimeter Institute in Waterloo, Ontario on May 7, 2008
Co-presented by The Philadelphia Science Festival Introduced by Dennis Wint, president and chief executive officer of The Franklin Institute Recognized for his groundbreaking discoveries in superstring theory, Brian Greene hosted the Public Broadcasting Service’s NOVA series based on his book, The Elegant Universe. A professor of mathematics and physics at Columbia University, he is also the author of The Fabric of the Cosmos and Icarus at the Edge of Time. He is well-known for making complex scientific principles accessible to general audiences. According to a reviewer for Publishers Weekly, the strength of his books lies ”in Greene’s unparalleled ability to translate higher mathematics and its findings into everyday language and images, through adept use of metaphor and analogy, and crisp, witty prose." In The Hidden Reality: Parallel Universes and the Deep Laws of the Cosmos, Greene shows how a range of different multiverse proposals emerges from theories developed to explain observations of both subatomic particles and the dark depths of space, featuring doppelgängers, strings, branes, quantum probabilities, holographs, and simulated worlds. Brian Greene will be interviewed by Dr. Steve Snyder, vice president of programs and exhibitions at The Franklin Institute. (recorded 4/28/2011)