February 20, 2012
By DENNIS OVERBYE
- Dr. Krauss delineates three different kinds of nothingness. First is what may have passed muster as nothing with the ancient Greeks: empty space.
- Second is nothing, without even space and time.
- There is a deeper nothing in which even the laws of physics are absent.
Why is there something, rather than nothing at all?
It is, perhaps, the mystery of last resort. Scientists may be at least theoretically able to trace every last galaxy back to a bump in the Big Bang, to complete the entire quantum roll call of particles and forces. But the question of why there was a Big Bang or any quantum particles at all was presumed to lie safely out of scientific bounds, in the realms of philosophy or religion.
Now even that assumption is no longer safe, as exemplified by a new book by the cosmologist Lawrence M. Krauss. In it he joins a chorus of physicists and cosmologists who have been pushing into sacred ground, proclaiming more and more loudly in the last few years that science can explain how something — namely our star-spangled cosmos — could be born from, if not nothing, something very close to it. God, they argue, is not part of the equation. The book, “A Universe From Nothing,” is a best seller and follows recent popular tomes like “God Is Not Great,” by the late Christopher Hitchens; “The God Delusion,” by Richard Dawkins; and “The Grand Design,” by the British cosmologist Stephen Hawking (with Leonard Mlodinow), which generated headlines two years ago with its assertion that physicists do not need God to account for the universe.
Dr. Krauss is a pint-size spark plug of erudition and ambition, who often seems to be jetting off in several directions at once on more missions than can be listed on a business card. Among other things he is Foundation Professor and director of the Origins Project at Arizona State University.
And he knows his universe. In 1995, he and Michael S. Turner of the University of Chicago made waves by arguing that many of the paradoxes regarding cosmology could be resolved if a large portion of the cosmos resided in the form of a hitherto-undiscovered energy, known then as the cosmological constant. Three years later astronomers discovered that the expansion of the universe was being accelerated by some “dark energy” that behaves exactly like the cosmological constant.
Dr. Krauss is also a prolific author of popular science books, including The Physics of Star Trek. And he has been an outspoken critic of attempts to introduce creationist ideas and to censor the teaching of evolution in schools and textbooks.
The new book grew out of a talk he gave in 2009 that got more than a million hits on YouTube.
The point of the book, Dr. Krauss, a self-described nonbeliever, writes at the outset, is not to try to make people lose their faith, but to illuminate how modern science has changed the meaning of nothingness from a vague philosophical concept to something we can almost put under a lab microscope.
How well you think he succeeds might depend on how far you yourself want to go down the rabbit hole of nonbeing. Why, for example, should we assume that nothingness is more natural than somethingness? Indeed, you might ask why it is that we think there is something here at all. The total energy of the universe might actually be zero, according to the strange bookkeeping of Einstein’s general theory of relativity, as Dr. Krauss points out. “The universe,” Alan H. Guth, a physicist at M.I.T., likes to say, “might be the ultimate free lunch.” Even space and time themselves might be a kind of holographic illusion, string theorists say.
You might think to dispute this by kicking a rock, but remember that both the rock and your foot are mostly empty space, prevented from intermingling by electric fields.
Dr. Krauss delineates three different kinds of nothingness. First is what may have passed muster as nothing with the ancient Greeks: empty space. But we now know that even empty space is filled with energy, vibrating with electromagnetic fields and so-called virtual particles dancing in and out of existence on borrowed energy courtesy of the randomness that characterizes reality on the smallest scales, according to the rules of quantum theory.
Second is nothing, without even space and time. Following a similar quantum logic, theorists have proposed that whole universes, little bubbles of space-time, could pop into existence, like bubbles in boiling water, out of this nothing.
There is a deeper nothing in which even the laws of physics are absent. Where do the laws come from? Are they born with the universe, or is the universe born in accordance with them? Here Dr. Krauss, unhappily in my view, resorts to the newest and most controversial toy in the cosmologist’s toolbox: the multiverse, a nearly infinite assemblage of universes, each with its own randomly determined rules, particles and forces, that represent solutions to the basic equations of string theory — the alleged theory of everything, or perhaps, as wags say, anything.
Within this landscape of possibilities, almost anything goes.
But even the multiverse is not totally lawless, as Dr. Krauss acknowledged. We are not quite there yet. At the very least, there would still be the string equations and those quantum principles that undergird them. Is quantum randomness the secret of existence?
Maybe in the true eternal multiverse there are truly no laws, Dr. Krauss said in an e-mail. Maybe indeed randomness is all there is and everything that can happen happens somewhere.”
It would be silly to think that we won’t have better answers and better questions 50 or 100 years from now, but for the moment this is the story science can tell. If you find it bleak, that is your problem. “The universe is the way it is, whether we like it or not,” Dr. Krauss writes.
It gets worse.
If nothing is our past, it could also be our future. As the universe, driven by dark energy — that is to say, the negative pressure of nothing — expands faster and faster, the galaxies will become invisible, and all the energy and information will be sucked out of the cosmos. The universe will revert to nothingness.
Nothing to nothing.
One day it’s all going to seem like a dream.
But who is or was the dreamer?