dipper@utastro.UUCP (Debbie Byrd) (10/06/84)
A basic law of physics says that all systems evolve toward greater and greater DISorder. So how did the whole universe evolve such ORDERLY structures as galaxies, stars and human beings? We talk about it -- after this. October 6 Order and Disorder In physics, it's known that entropy -- or the level of disorder -- increases as a system evolves. In other words, once you scramble an egg, it stays scrambled -- it doesn't spontaneously turn back into a whole egg again. Likewise, tidy rooms get messy -- and a sugar cube dropped in a cup of coffee dissolves and disappears. The list goes on -- but the idea is, in our universe, when things are left to themselves, they tend toward disorder. And yet -- the most widely believed theory about the birth of the universe says that it began in a Big Bang -- a state of unimaginable chaos. Later that chaos somehow evolved into the extremely orderly structures we know today -- majestically rotating galaxies made of billions of stars -- stars themselves that cycle through various predictable stages in evolution -- and, last but not least, those most complex of all known organisms -- human beings, who contemplate it all. How can a universe that tends toward disorder have evolved such orderly structures? That's the kind of question being asked in cosmology today -- the study of the whole universe. In the past few years, subtle variations on the Big Bang theory have begun to suggest ways in which the orderliness in our universe could have evolved from disorder. One new model is called the "inflationary" universe -- which describes a FLEETING INITIAL EXPANSION that took place in less than the first second after the Big Bang. Script by Deborah Byrd. (c) Copyright 1983, 1984 McDonald Observatory, University of Texas at Austin