Episode 159      34 min 13 sec
Lawrence M. Krauss: Before and after the Universe

Theoretical physicist Professor Lawrence M. Krauss discusses how investigating dark matter can shed light on the geometry of our universe, and what this means for our understanding of its origins and demise. With Science host Dr Shane Huntington.

"We have ideas about why the universe may be flat, but we were astounded to discover that the reason there's enough energy to make the universe flat is that that energy resides in empty space. And it's still a mystery." -- Professor Lawrence M. Krauss





           



Prof Lawrence M. Krauss
Professor Lawrence M. Krauss

Lawrence M. Krauss is Foundation Professor in the School of Earth and Space Exploration and Physics Departments, Associate Director of the Beyond Center, Co-Director of the Cosmology Initiative and Director of the exciting new Origins Initiative at Arizona State University, which will explore questions ranging from the origin of the Universe to the origins of human culture and cognition.

Until 2008 he was Ambrose Swasey Professor of Physics, Prof of Astronomy, and Director of the Center for Education and Research in Cosmology and Astrophysics. Krauss received his PhD from MIT in 1982 and then joined the Society of Fellows at Harvard University. He was appointed as a professor of physics and astronomy at Yale University in 1985, and then joined Case as Chair of Physics in 1993, a position he held until 2005. During this period he built an internationally ranked research center, and created such novel new programs as the Physics Entrepreneurship Masters Program. The author of 8 popular books including international bestseller, The Physics of Star Trek, and the award winning, Atom, and his most recent book, entitled "Quantum Man: Richard Feynman's Life in Science" which will appear in March of 2011, Krauss is also a radio commentator and essayist for newspapers such as the New York Times, the LA Times, the Wall St. Journal, and has written a regular biweekly column for New Scientist,and now writes a monthly column for Scientific American and also appears regularly on television.

Krauss is one of the few well known scientists today described by such magazines as Scientific American as a public intellectual, and with activities including performing with the Cleveland Orchestra, being a judge at the Sundance Film Festival, and his grammy nominated notes for Telarc Records, he has also crossed the chasm between science and popular culture. At the same time he is a highly regarded international leader in cosmology and astrophysics, and is the author of over 300 scientific papers, winner of numerous international awards for his research accomplishments and his writing (he is, for example, the only physicist to have been awarded the highest awards of the American Physical Society, the American Association of Physics Teachers, and the American Institute of Physics) and is a Fellow of the American Physical Society, and the American Association for the Advancement of Science. He has been particularly active in issues of science and society, leading the effort by scientists to defend the teaching of science in public schools, and to help define the proper limits of both science and religion, as well as defending scientific integrity in government. His essay in the New York Times on Evolution and Intelligent Design in May 2005 helped spur a recent controversy that has helped refine the Catholic Church's position on evolution. Most recently he led the call for a Presidential Debate on Science and Technology, is co-chair of the Board of Sponsors of the Bulletin of the Atomic Scientists, and on the Board of Directors of the Federation of American Scientists.

Credits

Host: Dr Shane Huntington
Producers: Kelvin Param, Eric van Bemmel
Audio Engineer: Gavin Nebauer
Episode Research: Dr Dyani Lewis
Voiceover: Nerissa Hannink
Series Creators: Eric van Bemmel and Kelvin Param

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VOICEOVER
Welcome to Up Close, the research, opinion and analysis podcast from the University of Melbourne, Australia.

SHANE HUNTINGTON
I'm Shane Huntington, thanks for joining us. The modern-day telescope is nothing like the refractor used by Galileo to discover Jupiter's four largest moons some four hundred years ago. Today, increasingly sophisticated telescopes, some of which now orbit the Earth, detect not only visible light but also frequencies at the afar end of the magnetic spectrum. The silent radio waves and gamma rays that these instruments detect allow us to explore the university in a way Galileo could have only dreamed about. They have painted for us a picture of the universe that expands back in time to when the universe first began. Our view of the heavens is far from complete, however, and our relentless search for understanding over the past century in particular has meant that physicists are being constantly challenged to find theories to fit their observations and observations to fit their theories.

Our guest today on Up Close Professor Lawrence Krauss is a theoretical physicist and one of the first to suggest that most of the energy of the universe resides in empty space and is unseen, a concept now referred to as dark energy. Lawrence Krauss is foundation professor of the School of Earth and Space Exploration and Physics Department, Co-Director of the Cosmology Institute and Director of the Origins Project at Arizona State University. He is a visiting Miegunyah Fellow at the University of Melbourne. Welcome to Up Close, Lawrence.

LAWRENCE KRAUSS
It's a pleasure to be here.

SHANE HUNTINGTON
Now, Lawrence, today when we talk about the universe, sooner or later the topic of the Big Bang seems to enter the picture. How did we come about this particular concept and what does it actually mean?

LAWRENCE KRAUSS
Well the Big Bang actually it was forced upon scientists. At the turn of the last century the conventional scientific wisdom was that the universe was static and eternal. It sort of looks that way when you look up at the night sky it's the same night after night. It seemed to be reasonable explanation for things. Through a series of initially sort of theoretical constructs it was realised that it's very difficult to have a static universe. Newton tells us why, because gravity sucks and you put a bunch of stars out there and they all tend to collapse together by their gravitational attraction. It's very difficult to have a static universe. But what's important to emphasise is that science is an empirical discipline and what really forced the realisation the universe is expanding was observation and experiment. The first key observation was made by Edwin Hubble in 1929 that as we look around us all galaxies are receding. On average they're moving away from us and what's even stranger is that those that are twice as far away from us are moving twice as fast and three times as far away from us three times as fast. Of course when you think about that it tells you immediately we're the centre of the universe, right? But that's not true, that's because of our myopic place in the universe. What it really means is that the universe is expanding. Of course if the universe is expanding you work backwards it was once smaller, you keep working backwards and once you can show that all, everything we see in the universe today was once together in a single point, smaller than the size of an individual atom. It's almost impossible to comprehend that, but that's the way it was.

SHANE HUNTINGTON
Assuming it's very hard for us to picture time frames that are beyond their own life cycle and even in the sort of geological sense I know it's very hard to picture these, what kind of timeframe are we talking about for the Big Bang?

LAWRENCE KRAUSS
Well we're talking about a very long time and what is amazing in fact is we now know that time according to great accuracy, I would not have thought it would have been possible in my lifetime. We now know that the big bang occurred 13.72 billion years ago, billion years ago. That is the age of the universe in most places except in some American states where it's still 6,000 years. But in the real world it is 13.72 billion years. That means that our sun by the way and Earth are relative newcomers. Our sun and Earth are only about 4.5 billion years old.

SHANE HUNTINGTON
In terms of actual physical evidence for the Big Bang itself, what is there that we can see at the moment?

LAWRENCE KRAUSS
Well there are three main pillars of the Big Bang; one was the discovery by Hubble that the universe is expanding, that galaxies are moving apart. That's profound evidence that the universe is getting bigger and was once smaller. Based on that we can work backwards with our physics. By the way that means when we look out at the universe we're doing cosmic archaeology. We are looking back in time. When I look at you I'm actually looking back in time, it's just a fraction of as second for the light to get from you to me but it's back in time. But when I look at a galaxy that's a billion light years away I'm looking back a billion years ago. That means when I see distant galaxies that are five billion light years away I'm actually not only looking at light that emitted before our sun and Earth formed, but the stars that I'm now seeing probably don't exist anymore. So as we look back in time we would expect to be looking back closer to the Big Bang. And if we work our physics back we find that as the universe gets smaller and smaller and smaller it was hotter and hotter and hotter. Back at a time when the universe was about one hundred thousand years old, the universe was so dense and hot that matter got stripped of its electrons. The radiation would break apart neutral atoms of hydrogen and you'd have a dense plasma. A dense plasma is opaque to radiation you can't see through it. So if we look back far enough a prediction of the Big Bang is that we should basically see that surface when the universe first became transparent and all that radiation came towards us. Just like in this room I can see the walls because light bounces off the walls and comes to my eyes because the room is transparent. Once the universe became transparent that radiation started coming towards us. So a prediction of the Big Bang is that there should be radiation coming at us from all directions.

It has cooled as the universe has cooled, it was three thousand degrees then, it is three degrees now. We see that radiation now, it is called the cosmic microwave background radiation. It was discovered by accident in New Jersey by two people who didn't know what the heck they were doing but they won the Nobel Prize nevertheless. So the discovery of the cosmic microwave background really confirmed that the early universe was hot and dense. The expanding universe tells us it's expanding. And the last really pillar of the Big Bang takes us back to a time when the universe was one second old. At that time the temperature of the universe was about ten billion degrees. It was hot enough for nuclear reactions to occur with abandon. Based on experiments in the laboratory here where we measure the rate of nuclear reactions we can predict at those early times what an abundance of light elements was formed. Before that time there were no elements. After that time the light elements, hydrogen, helium and lithium were created in that first few seconds or first few minutes of the Big Bang. The predicted abundance of those elements varies by ten orders of magnitude. When we look out at the universe we discover, bang on, twenty-five per cent of the universe is predicted to be helium, that's what we see. One part in ten billion is lithium, that's what we see. And by the way for your listeners, all your other elements that really are important for your life of the carbon, nitrogen, oxygen, iron, all those things were created much later in the dense core of stars which exploded, so you're really stardust.

SHANE HUNTINGTON
Now, Lawrence when we look back over the last one hundred or even few hundred years we see initially physics through Newton had a certain view of the universe and then Einstein and all that period around Einstein's discoveries around sort of early 20th century gave us a different view of the universe. What's the current model, at the moment, for how the universe works? I realise this could be a question that would take a month to answer?

LAWRENCE KRAUSS
Yes, there's many aspect of the model of how the universe works and I should say we don't have a complete understanding. In fact that's the great thing there are mysteries to be solved. In fact one of the biggest mysteries in physics was based on a relatively recent discovery which you alluded to. Our model of the universe is one in which by the way we are much more insignificant than we might have thought before. Because you can take all of the matter that we can see in the universe today with telescopes, the galaxies, stars, planets, any aliens, everything that's out there that we think of as a beautiful universe you get rid of that, all of that and the universe is largely the same. Everything we can see and everything we are made up of is literally a one per cent bit of pollution in a universe full of dark matter and dark energy.

What are those things? Well dark matter when we try and weigh galaxies, which we have been able to do, we'd find out that basically there's thirty to forty times as much stuff out there as meets the eye. So much stuff that our very successful calculations of the balance of light elements tell us there aren't enough protons and neutrons in the universe to account for all that stuff. It must be some new type of elementary particle. Which means it is not just out there; it's going through your body right now as you are talking to me and going right through the earth. It means we can actually do experiments here on Earth to look for it. So we don't know what it is. We think it's some new type of elementary particle, but there's a lot more of it than there is normal stuff. As wild as that is, what we've discovered is that even that is just the tip of a cosmic iceberg. Most of the energy in the universe resides literally in empty space. Empty space weighs something and we don’t have the slightest idea why it's there.

But when you add up all of that energy what you find is that the universe we live in is what's called the flat universe. Einstein told us that matter can curve space and our universe could live in one of several geometries as a result. In fact the reason I got into cosmology was in some sense to be the first person to know how the universe would end. I thought it seemed like a good idea at the time. Because a closed universe if it's full of matter, a closed universe is one that if you look far enough in one direction you'll actually see the back of your head, space will close on itself. This is a three dimensional closed universe not a two dimensional one, so it's very hard to picture. But that would be the way what would be. Such a universe if it's full of matter will expand, stop and re‑collapse. An open universe will keep on expanding forever to find that rate and a flat universe is just at the boundary between the two. You know once we discover the fact that the universe is expanding that became the Holy Grail of cosmology. Will that expansion end? To know whether it would end we had to know the geometry of the universe and that means we had to know how much stuff there was. Now that the dust has settled, we have found we live in a flat universe which is kind of the one that theorists like me thought we lived in, because it's the only mathematically beautiful universe. We have ideas about why the universe may be flat, but we were astounded to discover that the reason there's enough energy to make the universe flat is that that energy resides in empty space. And it's still a mystery.

SHANE HUNTINGTON
Do we know whether that expansion at the moment is sort of accelerating or decelerating?

LAWRENCE KRAUSS
Well in fact the reason we know there's energy in empty space is precisely from that observation. As I said gravity sucks. So the universe should have been slowing down. Astronomers looked out to try and measure the rate at which the universe was slowing down for a long time. Much to their amazement what they discovered as we look at distant objects that the universe is actually speeding up. There is only one way that that could happen. Well there are two ways. One the observations could be wrong. But they don't look like they are. The other way is that in fact there's energy in empty space, because the only place to get gravitational repulsion, anti-gravity if you will, is if you put energy in empty space. Amazingly if you add just the right amount of energy in empty space to the amount of energy in dark matter you get a flat universe which we have independently measured to be the case. So we needed that dark energy anyway but it is causing the expansion of the universe to accelerate and that means by the way that the future is going to be very different than we thought it would have been.

SHANE HUNTINGTON
For some years there was a lot of excitement around the area of string theory, is that something that is now off the boil?

LAWRENCE KRAUSS
Well I think it depends who you talk to. In theoretical physics one of the areas where we really still don't have a handle is when you take very small scales, where quantum mechanics is important. It turns out Einstein's general relativity is inconsistent with quantum mechanics, we can't put the two together. That means to understand the quantum mechanics of space and time, which is really what general relativity is a theory of on very small scales, we need a new theory. String theory was proposed to be such a theory and of course it's a very exiting idea. One of the side implications of it however, is that there must be many extra dimensions and you have to get rid of them by curling them up on a scale so small you can't see them. It is still a very attractive and interesting idea. The problem with it is that it's become very complex and it's not clear that it has anything to do with reality. The hope that it would lead us to a theory of everything has certainly not been realised. That does not mean it's wrong. It just means that it hasn't made the kind of progress that people hope for. In fact it really has not yet made any real contact with experiment. That means that it may not describe the universe in which we live. Once again I want to remind people that physics, even cosmology is an experimental science. Unless you can test an idea it really isn't scientific.

SHANE HUNTINGTON
This is Up Close coming to you from the University of Melbourne Australia. I'm Shane Huntington. Our guest today is Professor Lawrence Krauss and we're talking about the origins and future of the universe. Lawrence, when we look out into the universe at the moment, as you say we can go back a fair way in time. We can look at so many different objects in different wavelengths. Are there objects out there that we just don't understand in terms of how they work at the moment?

LAWRENCE KRAUSS
Well yes there's a lot we don’t understand about the universe. There's all we do and every time we open a new window on the universe we're surprised. There are lots of puzzles. I'll give you a recent example of a recent discovery. We know now that the centre of most galaxies are huge black holes. Black holes are objects that are collapsed matter that is so dense that light can't even escape from them. They are probably the most exotic gravitational objects in the universe. That the centre of most of our galaxies are a million or a billion solar mass black holes today. Nowadays we can sort of think they form from things collapsing and stars merging. But in the earliest moments of the formation of structure in the universe in the first billion years of the universe or few hundred million years, we would have thought that objects, small objects like stars would form and such. But what’s recently been discovered is evidence for super massive black holes even in the earliest structures of the universe.
How did they form is a mystery and in fact it's a chicken and an egg. We don't know whether the existence of these super massive black holes are necessary for galaxies to form around them or whether the galaxies were necessary for the formation for the super massive black holes. So that's one of the reasons we want to actually build a successor to the Hubble space telescope which is called the James Webb space telescope and unfortunately it's in precarious ground. With cost overruns there's discussion of cancelling the project. It would be devastating to the future of astronomy and science if we did. So that's one example on a large scale. On small scales there's a tremendous amount we don’t know which is why we built the Large Hadron Collider, which is now running in Geneva. There's this beautiful synergy by the way between particle physics and cosmology which is where I work. Because if the universe is expanding that means everything was once contained in a region which is very small, that means in order to understand how it got to be that way we have to understand the physics of the very small, which is where we're exploring it at accelerators like the Large Hadron Collider. And there we're trying to understand why particles have mass, a whole bunch of questions related to ultimately the question of how we got here. Ultimately all these questions come down to the same questions that people ask themselves when they were growing up. How did we get here? Where did we come from? Where are we going? Those are the very questions that science deals with ultimately.

SHANE HUNTINGTON
Now in terms of some areas of particle physics and the materials we're talking about such as anti‑matter for example, we’ve been talking about this now for over half a century, it's been around for a while. Dark energy and dark matter are relatively new.

LAWRENCE KRAUSS
Yes.

SHANE HUNTINGTON
Can you explain what are they exactly? I mean how do we describe them relative to other particles?

LAWRENCE KRAUSS
As I like to say anti-matter is not really strange. It's strange in the sense that Belgians are strange. Now what do I mean by that? Go into a large room and ask how many people are from Belgium and you won't get any hands put up. It doesn't mean that they're strange, you go to Belgium and everyone is fine, it's just you don't often see Belgians around. The same with anti‑particles. They're identical to particles. If the universe was made of anti-matter it would be largely the same. You would have anti-lovers sitting in anti-cars making anti-love under an anti‑moon. It's an amazing fact of physics that matter and anti-matter are more or less identical. It turns out relativity and quantum mechanics applies for every particle that we know, like protons and electrons, there must exist particles that have the opposite electric charge and the same mass. We call them anti-protons and the anti‑electron we call a positron. It was an amazing discovery that came out of a theoretical prediction actually. The prediction was so strange that the person, Dirac, who proposed it didn't even believe it. It was only again the experimental discovery of anti-matter and cosmic rays that convinced us it was there. But what's really strange is we appear to live in a universe that's essentially made of matter. There's not much more anti-matter left. We can create it at accelerators, it's not just science fiction. We talk about it in Star Trek and other things but we make anti particles in particle accelerators and we smash them against particles. because the interesting thing that happens when you have matter and anti-matter and it comes together is they annihilate. We use that to try and explore the fundamental properties of matter.

So it is a big mystery by the way and one of the things that particle physics is trying to deal with to try and understand. Why we live in a universe of matter and not a universe of anti-matter or more simply the kind of universe that you would have created had you created a universe and I would have, a nice simple universe with equal amounts of matter and anti-matter. That would be the most sensible universe. If that was the universe however we wouldn't be here, because all the matter and anti-matter would have annihilated at the beginning of time leaving nothing but pure radiation left. It would have been a beautiful universe but a very boring one. So happily that small asymmetry between matter and anti-matter produced all of the history of the universe and all of the tragedy and glory that now makes human history possible. What is interesting is that we can take anti-particles and could you make anti-atoms? Could you take an anti-proton and have an anti-electron orbiting it to make an anti-hydrogen atom. We're just beginning to be able to do that. Then when we do that we can explore and verify our predictions that these anti-atoms are exactly the same as regular atoms. If they're different at all it'll tell us there's something fundamentally wrong with our particle physics' theories.

SHANE HUNTINGTON
As we move into the new understanding with dark matter and dark energy, how do we distinguish those from these other particles?

LAWRENCE KRAUSS
Well dark matter, you know people may say it's like counting angels on the head of a pin. You invented all of this stuff to explain the stuff you can't see, it's not real science. Well that's not quite true in fact it's not true at all. In the first place we've inferred its existence by weighing galaxies, so we know it's there. It’s not just some invention of our minds. But more importantly when we try and understand fundamental particle physics at the scale we're looking at, at the Large Hadron Collider it turns out there are puzzles and each of those puzzles to be resolved requires the existence of new particles it turns out. So we're recently convinced there are new elementary particles in nature we haven't yet seen. That's one of the things we're trying to explore at the Large Hadron Collider. It turns out almost every one of these theories which solve a problem in particle physics predicts the existence of particles which would be natural candidates for the dark matter in the universe. So it's a very interesting and exciting time because there are two different ways we might discover the identity of dark matter.

One is by building experiments underground and waiting for this dark matter to come through the Earth and bounce off detectors underground and we're building them. In fact one of the things I'm proud of is I proposed many of those experiments. But the other possibility is instead of waiting to detect he particles that were created at the beginning of time, we might create them now in the Large Hadron Collider. So we might be able to create the very particles we're looking for to make up the dark matter. So it's a race. Will we detect them first at the Large Hadron Collider or underground or neither. We don’t know the answer and only time will tell. But we will, ultimately, I think in our lifetime, certainly know the identity of dark matter and know what is the dominant particle that makes up the universe. Dark energy is much more difficult. There's no experiments we can do on Earth to probe it. The only way we can probe it is by looking at the expansion of the universe itself. That means that it's much more difficult to explain. It means we're going to have to have a good idea rather than a good experiment. Good ideas are a lot harder to come by. A good idea may come in a decade, there may be a young Einstein listening to this podcast now who comes up with the idea a decade from now. It may be a hundred years, it may be a thousand years.

SHANE HUNTINGTON
This is Up Close coming to you from the University of Melbourne Australia. I'm Shane Huntington. Our guest today is Professor Lawrence Krauss and we're talking about the origins and future of the universe. So, Lawrence, I have to return to something that you mentioned before and that is the concept of weighing a galaxy. How do you go about that and when you do so what do you find that's inconsistent?

LAWRENCE KRAUSS
Well it's very simple, you pick it up and you put it on a big scale. It's really very trivial. Actually it's not so easy but if you think about it the way we weigh things is by using gravity. We literally use gravity. In fact  the way we know the mass of the Earth and the sun is by using gravity. Newton told us for example that objects orbit around the Earth and the speed with which they orbit around the Earth depends upon the mass of the Earth. In fact by the way that is exactly the way we know the mass of the Earth. We measure the velocity of satellites, including our moon, around the Earth as a function of their distance and it tells us precisely the mass of the Earth. The same is true for the sun. The way we weigh the sun is by measuring the speed of the plants around the sun. If the sun were heavier, the planets would be moving faster. Using that technique in principle we could determine the mass of the sun to one part in a billion. It turns out we can't with that accuracy because gravity is the weakest force in Nature. Most people don’t realise that. But gravity is so weak it's very hard to know its strength exactly. We only know the strength of the gravitational force to one part in a hundred thousand or so. So that limits our accuracy of weighing the sun.

Physics is like Hollywood, if it works copy it. If it works for the Earth and it works for the sun we use it to weigh the galaxy. So we weigh the galaxy by measuring the speed of objects like our own Sun around the centre of the galaxy. Our sun is at the edge of the galaxy it's moving at two hundred kilometres per second around the galaxy orbiting it every one hundred million years or so. Just from its distance and its speed we can determine how much mass is pulling it in. When we do that, we jump up and down because we discover by that technique that the mass of our galaxy is about a hundred billion times the mass of our sun. We determine the number of stars in our galaxy it's about a hundred billion stars. So everything hangs together and you say great. But to do a better job you want to use many objects, not just one, and objects that are further and further out allow us to do a better measurement. There are some objects further and further out but these strange thing is when we measure those objects they're moving much faster than they would be if all the mass of our galaxy was contained in the visible region that we see. They're moving so fast that there must be more mass out there on scales larger than what we see, in fact at least ten times more stuff and that's how we determine the existence of dark matter.

SHANE HUNTINGTON
Lawrence, is it possible at this point that our overall model of the universe is just simply wrong and we are patching it up with these various ideas? Or have we got enough evidence at the moment, we're on such a strong ride, that you know it's unlikely we'll have to go back to the drawing board?

LAWRENCE KRAUSS
The fundamental picture of the Big Bang is really unassailable at this point. The evidence for not only the existence of the Big Bang but the age of the universe comes from so many different sources and it all agrees that it's really unassailable. But that does not mean we have a complete picture of the universe. Our picture of the universe is limited by what we can see and first of all limited by the fact that we only have one universe to test. There may be many universes we can just see one. So there's no doubt when it comes to the very earliest moments of the Big Bang times where we can't yet probe directly with experiment, almost anything goes. We don’t understand T=0, we don’t  understand the very earliest instance of the Big Bang because we need a theory of quantum gravity to understand that very well. It's also true that on the larger scales we are limited by the fact that we can only see as far as we can see since the Big Bang. So is our universe infinite for example? A flat universe mathematically is an infinite universe. But we can't see infinitely far. So we don’t know what happens in scales larger than what we can see. So our picture of the universe hangs together. We know we live in a universe that looks flat on the scales we can see. There was a Big Bang and we can work backwards and test our picture back to maybe a millionth of a second after the Big Bang. But before those times and on scales larger than that we really can't say for certain because we can't see, we can't measure.

SHANE HUNTINGTON
When we think about the universe constantly expanding and changing, if we were to project forward, you know hundreds of millions of years, and look out with the telescopes and so forth we have today, what would we be seeing?

LAWRENCE KRAUSS
Well I've been thinking about that a lot. It's amazing in a sense, it was kind of shocking and for some people depressing. What we'll see is nothing in a sense because if the universe is accelerating then all distant galaxies are moving away from us faster and faster. Eventually, believe it or not they'll be moving away from us faster than the speed of light. Now that sounds impossible because you learn in school that nothing can travel faster than the speed of light. But you've got to be like a lawyer and parse that a little more carefully. Nothing can travel through space faster than light, but space can do whatever the heck it wants. If it wants to carry objects away from us faster than light, like a surfer on a wave that's being carried out to sea. If the wave is going in the wrong direction then that's fine. So in fact what's happening is that objects indeed are moving faster and faster and as they approach the speed of light they'll disappear and it'll take a long time, hundreds of billions of years. But eventually all the galaxies outside of our local cluster of galaxies which are bound to us right now will disappear. The universe will look in the far, far future much like the universe we thought we lived in at the turn of the last century. Because observers at that time they'll discover quantum mechanics and electromagnetism and gravity and build telescopes. But when they do they'll see an empty universe with one large galaxy in which they live and the best picture of the universe will be a static universe with a single galaxy which is the universe which we thought we lived in, in 1900. It's kind of poetic in that sense, but sad in a way that the evidence and knowledge of all that we now see will disappear in a sense. But that should be sobering in a way. The good news as I like to say is that we live in a very special time. The only time in which we can observationally verify that we live in a very special time. But that's being facetious. What I really mean is that there may be things that we could have seen five billion years ago or things that we'll be able to see in a hundred billion years which will change aspects of our picture and that we have to have a certain humility. But it is indeed sobering to think that in the far future the universe will have disappeared essentially. I use that by the way to try and argue in my own country with Congress to try and fund cosmology now while we still have a chance. But unfortunately two trillion years is a little longer than the average lifetime of a congress person so that doesn’t seem to have much impact.

SHANE HUNTINGTON
Lawrence, you mentioned before this strong tie in between cosmology and particle physics. If we come back down to Earth for a moment and just talk about the experiments going on in the Large Hadron Collider. As you know there's been a lot of community concern with regards to these experiments. Given the lack of a complete picture of the universe is there any issue with the sorts of experiments we're doing at the Large Hadron Collider at all?

LAWRENCE KRAUSS
No essentially because you know what people don’t realise is there's alot we don't know about the universe but there's a lot we do know. That's what you have to remember. For example while the Large Hadron Collider is the highest energy machine humans have ever produced, every second of every day we are bombarded by cosmic rays from space that have much higher energies than are being produced in the Large Hadron Collider. They are so diffuse that we can't use them to test things. But the fact that people for example are worried about creating black holes that swallow the Earth. The Earth has been bombarded by high energy cosmic rays for four and a half billion years and we're still here. The moon is still here, look up tonight and you might see the moon. It's being bombarded, it's got no atmosphere to protect it. So we often justify the Large Hadron Collider by saying we’re recreating the Big Bang. But it's not a very big bang. What we're doing is perusing energies over microscopically small regions to see what happens. But the actual amounts of energy involved are so microscopic that we're not creating a Big Bang, we're just creating an extremely small region which we can heat up to recreate the early conditions of the Big Bang. So there's lots of reasons, independently to know that we're not going to destroy the universe with the Large Hadron Collider. So you can rest easy.

SHANE HUNTINGTON
Lawrence, you mentioned before there are a variety of projects in areas where Congress and others in the US, and I guess around the world, have concerns about funding this type of work. What is the justification for funding this sort of work, especially the stuff that's down the very theoretical end?

LAWRENCE KRAUSS
You know as far as I know people don't ask the question, you know what's the value of a Mozart symphony or a Picasso painting? Science is a cultural activity and it's produced some of the most amazing ideas that humans have ever thought about. The cultural value of science of understanding where we are and where we come from is the same as art, music and literature. Great art, music and literature forces us to reassess our place in the cosmos. That's what science does at its best. If we are so impoverished that we have to stop asking questions about where we came from and where we're going it's indeed a sad time. These are the most interesting questions that humans have every asked. By comparison to the money we spend on many other things, that is, in my opinion, much more useless, the investment is very small. So if we are at the point where we have to say look, we can't stop asking these esoteric questions that change our picture of ourselves then it's a sad time for humanity.

SHANE HUNTINGTON
Can we also argue that as is the case with many of the theoretical predictions made by Einstein over quarter hundred years ago we now have a variety of technologies that are in our homes. Is there hope that that's where this will head as well?

LAWRENCE KRAUSS
Well you know we can justify what we do by the technological spin-offs. It's true general relativity is esoteric but you couldn't use your GPS machine without it. It turns out the effects of general relativity on the satellites have to be incorporated. If not, within second, you'd lose all knowledge of where you were on Earth with a GPS satellite. So it's true that even the most esoteric ideas sometimes have technological spin-offs. But I think it is misplaced to argue for doing fundamental research just because of its technological spin-offs. The questions themselves have to be worth asking to be able to spend the money on. But having said that it is absolutely true that our current standard of living vitally depends on the curiosity driven research that was done a generation or two before. Things like the transistor. If you ask people to build better computers in the 1940s they would have had wheels and cogs and of course the transistor changed everything. Discoveries come along that change everything when you didn't expect it. They come along because you didn't know what you were looking for. If we stop investing in fundamental research now it is true that our standard of living, a generation from now, our children, the legacy we leave our children, will be much poorer. In fact it's one of the reasons why I argue that, to make an Australian example, since we happen to be having this conversation in Australia. It's important for Australia not just to live off selling its natural resources but to think about the future, about doing fundamental research. Because the countries that are going to be able to compete in the 21st century are those that invest in technology and ideas and research. So there is of course not just this altruistic, idealistic notion of understanding the universe. If we want to address the challenges of the 21st century from energy to climate change, we need to invest in fundamental research now.

SHANE HUNTINGTON
When we fall back to the issues around the universe and cosmology, where do you think we will be in say fifty years from now in terms of the big things that will come up?

LAWRENCE KRAUSS
I'm always wary about predictions about the future. People always ask me what's the next big thing? I say, if I knew I'd be doing it. But what I'm convinced of is that the most important things that we know, fifty years from now, will be the things we had no idea about right now. Nature continues to surprise us in ways we could never have expected. Nature is much more imaginative than the human imagination is. In order to make progress we keep having to question nature, explore it because it will yield those surprises that will change not just our picture of ourselves but the way we carry out our lives.

SHANE HUNTINGTON
Professor Lawrence Krauss from the Arizona State University, thank you for being our guest on Up Close today and giving us an understanding of how theoretical physicists measure and explain the universe.

LAWRENCE KRAUSS It's been a pleasure, thank you.

SHANE HUNTINGTON
Relevant links, a full transcript and more info on this episode can be found at our website at upclose.unimelb.edu.au.  Up Close is a production of the University of Melbourne, Australia. This episode was recorded on 25 August 2011. Our producers were Kelvin Param and Eric van Bemmel. Audio engineering by Gavin Nebauer, background research by Dyani Lewis. Up Close is created by Kelvin Param and Eric van Bemmel.  I'm Shane Huntington, until next time, goodbye.

VOICEOVER
You've been listening to Up Close.  For more information visit upclose.unimelb.edu.au. Copyright 2011, The University of Melbourne.


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