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Fri January 13, 2012
Lawrence Krauss On 'A Universe From Nothing'
IRA FLATOW, HOST:
Speaking of dark matter and space-time, one of the major questions about our universe is how did it all come into being, and my next guest tackles that question in his new book, "A Universe from Nothing: Why There is Something Rather than Nothing." Lawrence Krauss is also a foundation professor and director of the Origins Project at Arizona State University in Tempe. He's also in our NPR Washington studios. Welcome back, Lawrence.
LAWRENCE KRAUSS: It's always good to be back, Ira.
FLATOW: What about this graininess stuff? You were listening to that. What do you think about that experiment?
KRAUSS: Well, that was a speculative idea, and most speculative ideas are wrong, and that's why it takes a while to make progress. And so I - in some sense I wouldn't call it a failure for theory. One of the most exciting, or two of the most exciting states to be in if you're a theorist are either wrong or confused.
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FLATOW: Speaking of which, I'm sure you're going to leave us in an enlightened state by the time you're done today, talking about your book. The title of your book, give us a thumbnail sketch of how you get something from nothing.
KRAUSS: Well, the title of the book, "A Universe from Nothing: Why There is Something Rather than Nothing" deals with this question. It's been around for as long as people have really started to ask questions about the universe and is really at the heart of a lot of the world's religions. Why is there something rather than nothing?
If we live in a universe full of stuff, how did it get here? And many people think that very question implies the need for a creator. But what's truly been amazing, and what the book's about is the revolutionary developments in both cosmology and particle physics over the past 30 or 40 years that have not only changed completely the way we think about the universe but made it clear that there's a plausible case for understanding precisely how a universe full of stuff, like the universe we live in, could result literally from nothing by natural processes.
And while it's a little pretentious, I'll be pretentious anyway, the idea, I think, is similar, if you think about it, to the origin of life, Darwin's demonstration that life, which appears to be designed here on Earth, the diversity of life can actually arise, that diversity can arise by natural causes.
And we don't yet know the true origin of life, but we think we'll understand it by chemistry, and what we're discovering is that in fact physics has suggested that maybe the same is true for the whole universe, that we don't need a creator.
And I guess most importantly that the question why is there something rather than nothing is really a scientific question, not a religious or philosophical question, because both nothing and something are scientific concepts, and our discoveries over the past 30 years have completely changed what we mean by nothing.
In particular, nothing is unstable. Nothing can create something all the time due to the laws of quantum mechanics, and it's - it's fascinatingly interesting. And what I wanted to do was use the hook of this question, which I think as I say has provoked religious people, as well as scientists, to encourage people to try and understand the amazing universe that we actually live in.
FLATOW: 1-800-989-8255 is our number, we're talking with Lawrence Krauss author of a new book, which talks about, you know, how the universe began, where it's heading, how we got here, all that kind of stuff, "A Universe from Nothing: Why There is Something Rather than Nothing."
And if you'd like to ask Lawrence a question and get in on the conversation, maybe you have a question about how the universe is working, as I say our number is 1-800-989-8255. Tweet us @scifri, @-S-C-I-F-R-I. Go to our Facebook page, /scifri, and our website at sciencefriday.com.
We'll take all of your questions and put them all together and ask Lawrence to talk about them. So stay with us. We'll be right back after this break.
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FLATOW: I'm Ira Flatow. This is SCIENCE FRIDAY, from NPR.
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FLATOW: You're listening to SCIENCE FRIDAY. I'm Ira Flatow. We're talking with Lawrence Krauss, who is author of "A Universe from Nothing: Why There is Something Rather than Nothing." He's also a foundation professor and director of the Origins Project at Arizona State University in Tempe.
Our number, 1-800-989-8255. How did the idea - how did - you said that the physics has changed, what we know about the universe has changed so much, dramatically over the last few years, especially the idea that what we think of empty space is really not empty, correct?
KRAUSS: That's exactly right. Empty space is a boiling, bubbling brew of virtual particles that pop in and out of existence in a time scale so short that you can't even measure them. Now, that sounds of course like counting angels on the head of a pin; if you can't measure them, then it doesn't sound like it's science, but in fact you can't measure them directly.
But we can measure their effects indirectly. These particles that are popping in and out of existence actually affect the properties of atoms and nuclei and actually are responsible for most of the mass inside your body. And in fact, really one of the things that motivated this book was the most profound discovery in recent times, and you even alluded to it in the last segment, the discovery that most of the energy of the universe actually resides in empty space.
You take space, get rid of all the particles, all the radiation, and it actually carries energy, and that notion that in fact empty space - once you allow gravity into the game, what seems impossible is possible. It sounds like it would violate the conservation of energy for you to start with nothing and end up with lots of stuff, but the great thing about gravity is it's a little trickier.
Gravity allows positive energy and negative energy, and out of nothing you can create positive energy particles, and as long as a gravitational attraction produces enough negative energy, the sum of their energy can be zero. And in fact when we look out at the universe and try and measure its total energy, we come up with zero.
I like to think of it as the difference between, say, a savvy stockbroker and an embezzler. The savvy stockbroker will buy stocks on margin with more money than they have, and as long as they get that money back in there before anyone notices, and in fact if the stocks go up, they end with money where they didn't have any before, whereas the embezzler, of course, is discovered.
Well, the universe is a savvy stockbroker. It can borrow energy, and if there's no gravity, it gets rid of it back before anyone notices. But if gravity is there, it can actually create stuff where there was none before. And you can actually create enough stuff to account for everything we see in the universe.
But, you know, it's more than that because some people would say, and I've had this discussion with theologians and others, well, you know, just empty space isn't nothing. You know, there's space. How did the space get there? But the amazing thing is, once you apply in fact quantum mechanics to gravity, as you were beginning to allude again in the last segment, then it's possible, in fact it's implied, that space itself can be created where there was nothing before, that literally whole universes can pop out of nothing by the laws of quantum mechanics.
And in fact the question why is there something rather than nothing then becomes sort of trite because nothing is unstable. It will always produce something. The more interesting or surprising question might be why is there nothing. But of course if we ask that question, well, we wouldn't be here if that was true.
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FLATOW: 1-800-989-8255. In your book you talk about dialing backwards, first the idea that the universe is expanding at greater than the speed of light. Is that correct, still expanding?
KRAUSS: Oh, absolutely. In fact, the discovery of this dark energy has told us that the future will be quite different than we thought, and that's one of the things I talk about in the book. Because of this dark energy, this energy of empty space, which is gravitationally repulsive, it's causing the expansion of the universe to accelerate, to speed up.
In fact, the discovery of that was awarded this year's Nobel Prize. But if you think about what that implies for the future, distant galaxies are moving away from us faster and faster, and eventually they indeed will all be moving away from us faster than the speed of light, which is allowed in general relativity, and we won't see them.
And the universe, in the far future, will be cold and dark and empty. So in fact as my late friend Christopher Hitchens, who was writing the forward for the book before he passed away, used to say: Nothing is heading towards us as fast as it can. So another answer to the question why is there something rather than nothing is just wait.
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FLATOW: And of course we're getting questions already. Here's a tweet from Maggie Kelley(ph), who says: So if space is infinitely expanding, what is it expanding into?
KRAUSS: Well, that's a good question. It's a question people often ask. And the answer is it doesn't need to expand into anything. The only two ways I know to try and explain this - well, the simplest way perhaps is to think of a rubber bedsheet that's infinitely big. Now stretch it. It's now bigger, but it wasn't expanding into anything because it was already infinitely big.
Now, if you don't like infinities, and there's a good reason to not be comfortable with infinities, just think of a balloon, and of course when you blow up a balloon, you think, sure, it's expanding into the room, but that's because you've embedded this two-dimensional surface of a balloon into this three-dimensional space.
But if the two-dimensional surface of the balloon was all there was, as it expanded, the balloon would get bigger, and every dot on that balloon, if you painted dots on that balloon, would move away from every other dot, but it wouldn't be expanding into anything, it would just be getting bigger.
So our universe, in fact, doesn't need to expand into anything. Space can expand on its own, whether the universe is finite or infinite, without boundary and without expanding into anything.
FLATOW: Let's go to Scott in San Francisco. Hi Scott, welcome to SCIENCE FRIDAY.
SCOTT: Hi, and thanks for taking my call. I'll make it quick. I was just wondering if - are some ideas being investigated in space-time recently, in terms of the Higgs field and the Higgs Boson, are these in some way kind of a revisiting of the idea of aluminiferous ether, as they used to talk about? I know there's differences, but is this kind of ether revisited now?
KRAUSS: Well, that's a good question. In a kind of philosophical sense, yes. Both the Higgs field and this dark energy that's permeating everything are indeed permeating empty space. And in that sense empty space is - has properties that you would not otherwise imagine, just like we - they used to imagine as an ether.
Of course, a difference was the ether was thought to be necessary to propagate light, and it was also thought to create a special frame of reference, and neither of these things do that. So neither of these things are of ether.
But in a philosophical sense they hearken back to the idea that empty space is full of something.
FLATOW: 1-800-989-8255. You mentioned in your book that we are lucky to be living in this time in the universe.
KRAUSS: Yeah, I mean for a variety of reasons. One is in the far future, and by the far future I mean hundreds of billions of years, astronomers and radio hosts on planets around other stars will look out at the universe, and what they'll see is the universe we thought we lived in 100 years ago, all of the other galaxies will have disappeared expect for our own, and people will assume, or beings will assume, they live in a universe that's basically infinite, dark and empty except for one galaxy, with no evidence of the Big Bang.
So we're living at this rare cosmic instant in which we're lucky enough to observe the Big Bang. By rare - by cosmic instant I mean a few hundred billion years, but in a cosmic sense that's an instant. And so we're fortunate to be able to see that. At the same time, of course, it should give us some cosmic humility because it suggests - it indicates something that's very important to realize.
When you're talking about the whole universe, we're limited by what we can see because science is an empirical discipline, and we have to be able - and the universe continues to surprise us, and it only can surprise us if we can measure it. And we're stuck in one universe, and we're stuck at the time we live in, 13.72 billion years after the Big Bang, and maybe a lot earlier we might have been able to discover other things, or a lot later, but we are fascinatingly lucky at this point to be able to see the evidence of the Big Bang.
And moreover, in even a grander sense, when one talks about a universe that could easily have come into existence by accident, I even show how current theory suggests maybe even the laws of physics themselves came into being by accident, with no purpose, no design, you might get depressed.
But from my point of view, it's really exciting and should energize us because it suggests that we're unbelievably fortunate that we happen to live in a universe that not only supports life but that consciousness has evolved, and we can appreciate this remarkable universe around us, and we should make the moment - most of our brief moment in the sun.
We should provide the meaning of the universe in the meaning of our own lives. So I think science doesn't necessarily have to get in the way of kind of spiritual fulfillment. In fact, I would argue the real story of the universe is far more interesting than any myths or fairy tales that people wrote thousands of years before they even knew the Earth went around the sun.
FLATOW: We're talking to Lawrence Krauss, author of "A Universe from Nothing: Why There is Something Rather than Nothing." Let's go to John(ph) in Salt Lake City. Hi, welcome.
JOHN: Thank you. Yeah, I just had a comment. I thought maybe it would be a better idea to call it God's glue rather than dark matter, just to comment. Thanks.
FLATOW: All right.
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KRAUSS: Well, you know, you hearken back to the statement of Steve Weinberg, which is really true. I put it a slightly different way. The universe is the way it is whether you like it or not. And you can call it whatever you want, but - and you might - and scientists might want something, and religious people might want something too. And I think the great difference and the great wonder of science is that our faith is shakable, not unshakable, that if we discover the universe isn't the way we wanted it to be, well, too bad.
In fact, we learn to like it even better.
FLATOW: 1-800-989-8255. Gary in Groveland, California. Hi, Gary.
GARY: Hi, thank you for taking my call.
FLATOW: Go ahead.
GARY: With all due respect, and I find what you're saying fascinating, but where is the practicality for us on Earth? What is it doing for us today or even in the very near future?
KRAUSS: Well, you know, it's a good question. And I put it back to you. I'd say, well, what does a Bach cantata or a Picasso painting do for us? I think the point is we are human beings, and one of the most wonderful aspect of being human beings is being creative and asking questions and trying to understand our place in the universe. And it is absolutely true that understanding the beginning and end of the universe is not going to produce a better toaster. But I'm always amazed that people - for me, one of the great virtues of science is it's a cultural activity, like art and literature and music. It enhances the experience of being human, and it addresses the questions that I'm sure you've asked about your own existence.
And if we can get new insights into our own existence and our place in the cosmos, well, that's what happens when we attend a good play or see a good painting. It gives us a new perspective of our place in the universe. And I happen to think that is worth it for its own sake. Plus, I happen to think these ideas are among the most remarkable and astounding ideas human beings have ever come up with. And we owe it to - we scientists owe it to the people to try and explain what's happening, and I think they enhance the quality of our existence. And...
FLATOW: And - I'm sorry.
KRAUSS: ...you know, it's not just technology. I think that's what is really important. Now, of course, there are always side benefits of doing - of every time we build a new big machine like the Large Hadron Collider and push the limits of technology, we develop tools that later on are used in society. But I don't think we should justify this remarkable adventure just because of the side effects.
FLATOW: 1-800-989-8255 is our number. Here - a tweet from Nate Koch(ph) says would there theoretically be no time if there were no matter or energy?
KRAUSS: It's a very good question. Of course, the answer is we don't know, but we do know that space and time are related to matter and energy and general activity. And we cannot follow the laws of physics back to T equals zero, because we don't have a full theory of quantum gravity. But it is quite possible, and indeed quite plausible, that time itself arose just as space arose. And there was no concept of time. It's something that arose as the world became classical. So it could be that the question what happened before the big bang is not even a good question, because before it had no meaning.
It's not necessarily the case because we really don't know. We are at the limits of our knowledge. And I guess that's something I want to stress for people who think, you know, I don't want to claim that we know the universe came from nothing. What is amazing is that we can see plausible mechanisms by which that happened. And I find that development truly astounding, and remarkable and worth celebrating.
FLATOW: I'm Ira Flatow. This is SCIENCE FRIDAY from NPR. Talking with Lawrence Krauss, author of "A Universe from Nothing: Why There is Something Rather than Nothing." Let's go to Bens Red(ph) in Manchester, New Hampshire. Hi there.
BENS RED: Hi. Thanks for taking my call. My question is, is (unintelligible) the essence of the sun shine? I mean, why the sun even shines? Why the (unintelligible)? Why do we assume (unintelligible) because it's kind of interesting the sun would shine every day and (unintelligible)? (Unintelligible) we don't understand, it doesn't make us that - should not allow us to say that no creator. It's kind of - we don't have an answer, and we (unintelligible) because maybe we (unintelligible) trying to get an explanation for our existence. So if our - I'll take my answer off the air.
FLATOW: OK. Thanks.
KRAUSS: Well, you know, look, I think the point is can - often, by the way, when we ask why questions, what we really mean is how. We don't really mean why. If we ask why are there nine planets or eight planets, if we get rid of Pluto, which I'll never do, we really mean...
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KRAUSS: We really mean, you know, how did those planets formed. And what's remarkable is to try and understand how the universe evolved, and that's what science tries to do – not really. And so - and when we ask why does the sun shine, what we really mean is what are the processes that cause the sun to shine? And one of the truly great and remarkable developments of the 20th century, which again is worth celebrating, is that we understand the processes that actually power the sun.
We do understand how the sun shines. Or, if you wish, why the sun shines, we have discovered nuclear energy. We've discovered that if you have a collapsing gas and it heats up, the nuclear reactions will produce an object that will burn brightly for 10 billion years, and we can actually predict its structure and compare it with observation. And that is amazing. That - without ever having been inside the sun, we now know how the sun works. Those things are worth celebrating.
And if you say, well, look, you don't need someone inside the sun, some divine intelligence constantly producing energy, I don't think that diminishes the universe. As Richard Feynman used to say, you know, just - if you understand how a rainbow works, it doesn't make it any less magnificent. It makes it more magnificent. And if it means that we don't need an intelligence intervening every day in our lives, I happen to think that makes the universe actually even more fascinating.
FLATOW: 1-800-989-8255 is our number. What about the idea of a multiverse, that there are infinite numbers of other universes around?
KRAUSS: Well, you know, that's something I deal with at the end of the book because, you know, it's not a concept that I'm pretty fond of, but it - we seemed to be driven there by our theories, and it does suggest the last bit, because some people, indeed when I debate this question of nothing, they say, well, look, you can get rid of space. You can get rid of stuff in space, the first kind of nothing. You can even get rid of space, but you still have the laws. Who created the laws?
Well, it turns out that we've been driven both from ideas from cosmology - from a theory called inflation or even string theory - that suggests there may be extra dimensions - to the possibility that our universe isn't unique, and more over, that the laws of physics in our universe may just be accidental. They may have arisen spontaneously, and they don't have to be the way they are. But if they were any different, we wouldn't be here to ask the question. It's called the entropic idea, and it's not - it's - it may be right.
It's not an idea I find very attractive, but it may be right. And if it is, then it suggests that even the very laws themselves are not fundamental. They arose spontaneously in our universe, and they're very different in other universes. And in some sense, if you wish, the multiverse plays the role of what you might call a prime mover or a god. It exists outside of our universe. And some people said, well, you know, physicists have just created this multiverse because they want to get rid of God.
Nothing could be further than - to - from the truth. The multiverse, we've been driven to it by our discoveries in cosmology and particle physics. We've been driven to that possibility, which seems plausible and maybe even likely. And if as a corollary, it allows for our universe to be spontaneously created and even the laws created, well, that's OK, but we weren't driven there because of some philosophical prejudice against a creator. That didn't even enter into the discussion.
FLATOW: All right, Lawrence. Thank you very much. You're always short of words, as usual.
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FLATOW: That's always great. (Unintelligible). Lawrence Krauss' new book "A Universe from Nothing: Why There is Something Rather than Nothing." You're getting even better as a writer. I mean, my standard is George Gamow, and you come very close to him as a writer in this book. So...
KRAUSS: Well, that's a great compliment. Thank you very much.
FLATOW: Terrific, easy read on this, "A Universe from Nothing: Why There is Something Rather than Nothing," Lawrence Krauss. Transcript provided by NPR, Copyright National Public Radio.