Monday, January 09, 2012

A Universe From Nothing

Lawrence Krauss had a new book out titled "A Universe From Nothing". In it, he makes the same claim as Hawking/Mlodinow did in "The Grand Design", that one can use just the physics that we know of today to show that the universe can spontaneously form out of nothing. He doesn't make use of the exotica that was employed in Hawking/Mlodinow book, and in that sense, this might be easier to digest and understand than that book.

First, you have to clearly define nothing, since it isn't an official scientific term. Scientists talk about empty space as well as a state in which space and time themselves don't exist. Either type of nothing can spontaneously produce stuff.

Empty space, as it turns out, can't be perfectly empty. Every type of matter has an equal and opposite counterpart, and pairs of particles and their anti-particles can spontaneously emerge from empty space and then disappear again.

One consequence of quantum mechanics' uncertainty principle is that a vacuum cannot remain perfectly empty forever. Not only will particles pop in and out of existence without violating the laws of physics, they have to.
I've mentioned Krauss's argument in an early blog post. So obviously, this book is now out. Now, of course, as expected, it doesn't garner as much brouhaha as Hawking's book, even if the argument is as damning (and in my opinion, stronger) than Hawking's. Did those people who made all those noises against "The Grand Design" got tired and ran out of rants?



Ryan Dickherber said...

I haven't yet read Krauss' book, but I've seen a presentation by him, and I have a slightly different take that is compatible with textbook cosmology. I think we need to recognize the counter-intuitive fact that time is finite. Although we intuitively believe that time must be infinite, and thus there must be some time before the big bang, this is not what the evidence says. Consider these two claims:

* The universe is 13.7 billion years old.
* The universe has always existed.

Both of these claims are true. It might seem that the second claim contradicts the first, but it doesn't if you recognize that time is finite. Since the universe has existed for all time, the universe has always existed. Therefore trying to explain how the universe has "come from nothing," which seems to imply a time before the big gang, is already to misunderstand the nature of time.

(If I have misunderstood Krauss' position, please correct me.)

Professor R said...

Looking forward to it, thanks for the heads up. is it out in Europe yet, do you know? Cormac

uchitrakar said...

When scientists say that the universe can simply come out of nothing without any divine intervention, they think of the universe in terms of its energy content only. In the book ‘The Grand Design’, page 281, scientist Stephen Hawking has written that bodies like stars or black holes cannot just appear out of nothing, but a whole universe can. What Hawking meant to say here was this: As the total energy of a whole universe is zero, so it can come out of nothing. But stars or black holes will fail to do so, because their total energy is not zero. But universe means not only its energy universe means its space-time as well. Do these scientists think that the total space-time of the universe is zero, and therefore, the entire space-time of the universe can also appear out of nothing?