The existence of this energy, called dark energy, has another consequence: It changes the picture so that knowing the geometry of the universe is no longer enough to determine its future. While this may be a disappointment, the existence of dark energy and a flat universe has profound implications for those of us who suspected the universe might arise from nothing.
Why? Because if you add up the total energy of a flat universe, the result is precisely zero. How can this be? When you include the effects of gravity, energy comes in two forms. Mass corresponds to positive energy, but the gravitational attraction between massive objects can correspond to negative energy. If the positive energy and the negative gravitational energy of the universe cancel out, we end up in a flat universe.
Think about it: If our universe arose spontaneously from nothing at all, one might predict that its total energy should be zero. And when we measure the total energy of the universe, which could have been anything, the answer turns out to be the only one consistent with this possibility.
This, of course, has more verification than Hawking's argument of using M-theory. At the very least, the presence and nature of dark energy can be tested. So such an argument is a lot more compelling and more difficult to refute than using an unverified theory that has yet to gain wide acceptance among physicists.
Of course, Krauss got into all of of this because he has his own book that will come out in 2011.
Mr. Krauss, a cosmologist, is director of the Origins Project at Arizona State University. His newest book, "A Universe From Nothing" will be published by Free Press in 2011.
I bet you the subject matter is as controversial as Hawking, but will it get the same level of attention? Probably not.
Zz.
0 Comments