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.
4 comments:
I wonder whether Krauss has run this past a conversation with someone who's ever read Genesis? God brought order out of chaos. Of course one might prefer to have no causation, in a hyper-instrumental way, but Physics is grounded in the idea that earlier stuff caused stuff now. So, God as initial condition (and occasionally boundary condition, in case of burning bushes). As we know, initial and boundary conditions fix everything in the bulk. Not that this is how it is, but the idea that some theory that relies on initial and boundary conditions can prove anything is ludicrous. There would have to be a proof that 4-dimensions is necessary, otherwise God might be what causes that to be how the universe appears to us.
I don't quite get your complain here, especially on your argument about the initial boundary condition.
If you buy into quantum fluctuation (and we have plenty of examples of that happening), then I don't see how your argument of requiring something to initiate the beginning is necessary here.
The requirement that something else must create something false flat because one can always ask what initiated or created god. Such a philosophy is self-contradictory.
Zz.
Peter,
I take issue with your (non-)answer.
'God brought order out of chaos'. This implies that there existed a state contemporaneous with god, to which god applied order. Who or what caused that prior state? - Indeed, who or what caused god? Nor can you declare by fiat that god does not need a cause, for that would be the fallacy of special pleading, not to mention extremely unlikely.
Next, as a matter of principle, I regard with extreme scepticism any statement about the natural world that seeks to justify its position by invoking the writings of Bronze-Age supernaturalists. Genesis? Really?
You also say: "There would have to be a proof that 4-dimensions is necessary, otherwise God might be what causes that to be how the universe appears to us."
I am surprised you do not see the folly of this argument.
A Norseman might have written: "There would have to be proof that lightning is necessary, othewise Thor might be what causes that to be how lightning appears to us."
God-of-the-gaps. We are ignorant about a lot of things in Nature, but that doesn't mean we'll always be so. Moreover, just plugging in {insert sociologically-indoctrinated super-entity here} to explain what we don't understand is tantamount to intellectual suicide and a guarantee of a return to the Dark Ages.
It seems to me that god is merely a placeholder for our ignorance.
Or, as a man burnt at the stake once said: Light is god's obscurity.
That our universe coming from nothing satisfies nergy conservation certainly is not enought to say that it can happen. "Can", as better, can be interpreted only as a self-ignorance statement (that all of us carry).
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