What is the Origin of the Universe and its Destiny?
• The Big Bang Theory is that the observable universe began as an expanding point, approximately fifteen billion years ago. Since then, the universe has continued to expand, gradually increasing the distance between our Galaxy and external galaxies. We observe this effect. Will this expansion continue forever, causing the universe to become ever colder and darker? Or will the expansion eventually halt and, perhaps, reverse leading to a “Big Crunch”? What came before the initial expanding point? • The gravitational pull of matter in the universe slows the expansion. If the matter is dense enough, the expansion will eventually reverse – gravity will win – and the universe will recollapse. If it is not, the expansion will continue forever. The density of matter in the universe will determine the ultimate fate of the universe. The minimum density required to halt the expansion is called the “critical density”. What is the density of matter in the universe? We don’t know the density of the
