Science Matters with Lawrence Krauss

Dec. 12, 2017

Transcript:

TED SIMONS: Coming up next on this special science edition of "Arizona Horizon," our favorite physicist Lawrence Krauss joining us with the latest on black holes, fundamental physics and quantum computers. It's a science special next on "Arizona horizon."

TED SIMONS: Good evening, and welcome to this special science edition of "Arizona Horizon." I'm Ted Simons.

TED SIMONS: Yes, it's time for another visit with one of our most popular guests, a science writer, renowned physicist and director of ASU’s origin institute, Lawrence Krauss. He joins us every month to talk about the latest science news.

LAWRENCE KRAUSS: I like that. Can I hear that again? TED SIMONS: What did you like about that? LAWRENCE KRAUSS: That whole build up.

TED SIMONS: Let’s see if you can handle it. Let’s see if you can deliver.

LAWRENCE KRAUSS: The pressure is big. TED SIMONS: We have five big stories. LAWRENCE KRAUSS: It’s end of the year stories. We should cover all the basis at the end of the year. Each one in a way reflects the future because we'll be talking about these next year. Each one has a tidbit that may be relevant to the future. We'll see how it goes.

TED SIMONS: Well, let’s start with this distant, humongous black hole. The biggest, most humongous black hole, what, like ever in the history of ever?

LAWRENCE KRAUSS: Not the most humungous black hole, but the farthest away and the earliest. It’s only 800,000,000 times the mass of the sun. There are actually a billion solar mass black holes and there are nearby galaxies. Our galaxy only has a 100 million solar mass black holes in the center. Most galaxies have black holes at the center. We don't know why. We don't know the chicken and egg problem, which formed first the black hole or the galaxy. It's a big open question, one we want to answer, but one way to answer it is to look back to see which formed first and trying to look to the earliest galaxies formed. That’s one of the reasons why I wanted to choose this story is that in the next year and a half, the James Webb Space Telescope will be launched. Its purpose is to look back to the first stars ever formed. The question is did the galaxies of stars form and then did those stars collide and collapse together to create the black hole or the black hole was there at the beginning and the galaxy fall into it? This amazing, massive black hole was seen in a galaxy that was only 690,000,000 years after the big bang which may seem like a long time but it’s really just the first 6% of the age of the universe, so early that it's just when galaxies are being formed. It's shocking, first of all, that you would see a black hole that early because if the black hole had to form from stars, first the stars would have to form, then collide together to form the black hole. How could you do all of that so early? Well, it turns out when you make stars, they blow up and you make heavy elements. When they looked at this galaxy, there were a lot of heavy elements. Somehow stars were forming early but how could they get together to be a 600-800 million solar mass black hole. No one knows so some people are speculating, maybe the black hole was in some way still there first and more over, as the universe evolved, what happened was that it cooled down and then once stars started forming, there was energy being emitted and hot gas was ionized because energy ionizes gas. And they looked at this thing at 690 million years after the Big Bang… By the way, we should say, the first thing we should answer, which you didn’t ask me, but you should have.
TED SIMONS: You haven't taken a pause yet.
LAWRENCE KRAUSS: I don't like to get you confused things too much with fact. How do we know it's there and how do we know it’s mass? You can't see a black hole. Why?
TED SIMONS: Because there is nothing there. It swallows all light. It swallows gravity. It swallows everything.
LAWRENCE KRAUSS: You are such a good student.
TED SIMONS: Thank you.
LAWRENCE KRAUSS: There you go. The point is, these massive black holes are surrounded by gas and it falls into the black hole and emits a tremendous amount of radiation. In fact, these super massive black holes are the brightest objects in the universe because they’re swallowing all the gas in the galaxy around them and they are hundreds of thousands of times brighter than stars because the hot gas is falling and it’s emitting x-rays and gamma rays. From the amount of light being emitted from the gas falling it , you can tell how big the black hole is because the bigger the black hole is, the more gasses that are going to be pulled in. This is so humungous and so bright that we know it's 800,000,000 solar masses.

TED SIMONS: The light that comes out… the light that is emitted, let’s just say, from the black hole, is it QUASAR?

LAWRENCE KRAUSS: That's right. It's not being emitted from the black hole. It’s being emitted from the gas falling into the black hole. That’s what we call quasar. Quasar, when they are first observed, people thought they were stars that were nearby because they were so bright, and then they were seen billions of years away, how could they be so bright? The only way is if a big black hole is gobbling up the gas from the galaxy. Looking at the light from the gas, you can ask does it have a lot of heavy elements? Is there evidence of neutral hydrogen? At 690,000,000 years, it turns out there is more neutral hydrogen than you might imagine. Star formation was just beginning to turn on when the universe is 700,000,000 years old. But where did they have the heavy elements come from? It’s all a big mystery. It's fascinating to discover this. It was like finding a needle in a haystack.
TED SIMONS: How was it found?
LAWRENCE KRAUSS: Well basically, they looked at as many galaxies as they could and looked at bright dots. It’s like a needle in the haystack as because there may be four or five of these in the universe, and they kept looking for black dots. If you are good at it, bright dots, if you look good at it, you can look at the spectrum of light and in ten minutes they could see if it's a QUASAR or not. They really were looking for a needle in the haystack. They found it and it challenges our pictures of which came first. We may not resolve it until we have the James Webb Space telescope, which is designed about ten times more powerful than the Hubble Space telescope, to look at the first galaxies ever formed and to look back beyond 600 million years, early in the history of the universe, to see when this happened.

TED SIMONS: But, we really are talking about 13 billion light years away. We really are watching what happened 13 billion years ago.

LAWRENCE KRAUSS: Exactly. Within 690,000,000 years after the big bang. We are looking at the universe before our galaxy even formed. It's about 12 billion years old. This is the primordial throws of the universe beginning to stretch its limbs.

TED SIMONS: Are you expecting more when the Webb Telescope becomes operational?

LAWRENCE KRAUSS: That's the whole point of it. Yeah.

TED SIMONS: I mean, are you really expecting to see more?

LAWRENCE KRAUSS: Oh yeah. We'll be able to look back at the earliest first stars ever formed and will be able to answer these questions. Did galaxies form? Which came first, the black hole or the egg of the galaxy and a lot more. That's one of reasons why it's been designed that way. It was supposed to launch in 2018 and now it's set for the spring of 2019. Stay tuned.

TED SIMONS: Let's move on to fundamental physics. A big story. What is the equivalence principle and why is everyone so excited to prove it wrong?

LAWRENCE KRAUSS: We always want to prove things wrong in science, in fact, it means we have more to learn. The equivalence principle is the very basic principle that it was a fundamental idea that led Einstein to general relativity. It’s quite simple. Two masses fall toward the sun in the same way whether they are made of gold or lead or wood. Why is that important? If gravity is due to the curvature of space, then all objects will move in the same way. Therefore, there should be no difference in the acceleration of objects towards the sun. for example, or towards the Earth depending on their makeup. That was tested periodically a century ago and it was pretty good. But what happened now, I think it was a French satellite sent up around the Earth with two masses made of the exact same configuration, hollow cylinders, made of two different materials. You had to ask, what kind of little forces do you have to put on them so they remain in the same configuration as the satellite moves around the Earth under the forces of the Earth and if you have to apply different bits of acceleration than one or the other that are different than the other, they are falling at different rates. It’s tested, this equivalence principle, more closely for solid, massive objects than anything else. It's something like one part in a million million or something like that. It's no big surprise that it's been confirmed but we always have to test these things because general relativity is a mystery. It's a beautiful theory, but as we talked about, it doesn't coincide with quantum mechanics. We can’t make it work. We are trying to look for a quantum theory of gravity. To understand the theory, you can either think really hard, that's hard, and no -- I was going to say something else. It's really hard to think hard because you could think for centuries and not get there. The better way is to make an experimental discovery that tells you what’s the right direction. That's the way physics usually works. We find things that don't agree with the ideas that we already have and they point us in the right direction. So looking in every possible way to find chinks in the armor of general relativity may lead us to a quantum theory of gravity.
TED SIMONS: Is that the same thing as this Lorentz… is that the same thing we are talking about?
LAWRENCE KRAUSS: It’s not quite the same thing.
TED SIMONS: So what’s that?
LAWRENCE KRAUSS: The equivalence principle is a fundamental aspect of general relativity. General relativity builds on special relativity, which is Einstein's theory that light travels at a constant speed no matter how you move in respect to it. That turns out, mathematically, to be a consequence of a fundamental symmetry of nature called Lorentz invariance. It's basically the fact that light will always travel the speed of light even if you have x-rays, they’ll travel the same as gamma rays, and there’s radio waves. Light always has the same speed. There’s only one example of Lorentz invariance. Let's see, one possibility is when you get to quantum gravity, there’s fundamental symmetry of nature, doesn't work anymore. So lets try to test to see if Lorentz invariance is satisfied in all sorts of exotic environments. Two other experiments to test to see if the speed of light is the same in all different configurations.

TED SIMONS: And?

LAWRENCE KRAUSS: Of course, it is.

TED SIMONS: Einstein always wins, doesn't he?

LAWRENCE KRAUSS: This is hard stuff. A non-result can be really important. It tells us maybe it's not the right direction to think about, but ultimately, the reason I wanted to determine these things, understanding the fundamental symmetries of nature and looking for chinks may be the way that leads us to quantum theory of gravity, which would ultimately allow us understand the beginning of the universe. So maybe that’s not next year’s physics, but it's the area we continue to test in general relativity. Everywhere we do, we are looking at ways we can test these fundamental symmetries are somehow break down. Something -- we know something has to give when you come together with quantum mechanics and gravity. If we do experiments, it will help us on the way.

TED SIMONS: Very interesting. That was pretty interesting.

LAWRENCE KRAUSS: Every now and then, it’s like monkeys on a typewriter.

TED SIMONS: Next, we have a shot of a couple of cylinders here.

LAWRENCE KRAUSS: Hold the shot for a second. Let's preface this. I wanted to have a little bit of physics -- this may seem totally useless, but physics is fun. It's about understanding everything. Here is an example of something you might thing is useless, but some physicists didn't. What these physicists did is take a lot of dice, put them in a jar and not shake them. What did they do?

TED SIMONS: They stirred them.

LAWRENCE KRAUSS: Just like James Bond. You look just like James Bond. Shaken but not stirred.

TED SIMONS: The older one? Look at these dice here. What are we looking at?

LAWRENCE KRAUSS: So the idea is if you shake things, and if you can do this with sand if you shake sand of different grains, you’ll find that if you shake it, eventually it will separate out into different levels or sizes of sand. Here are a bunch of unorganized dice on the left-hand side. Can you make them become organized? What they said is that it turns out if you shake them, you can never make them organized. Maybe you can stir them. Maybe you can make the two of them and take the jar and stir it back and forth and see if you can make it organized. First time they stirred it relatively slowly and let’s see what happens.

TED SIMONS: We have a video of the first time they stirred it relatively slowly.

LAWRENCE KRAUSS: There we go. They did this a hundred thousand times back and forth. After a hundred thousand times, you’ll see the video stop.
TED SIMONS: The camera is looking down on the dice.
LAWRENCE KRAUSS: You see that it’s not perfectly uniform. It's more uniform, but there are gaps and certain things are pointing in different directions. Then they tried the same thing stirring it faster. They tried different levels and couldn't make it work even after a hundred thousand times and after a certain rate of stirring got to a certain level, the following happen.

TED SIMONS: The next video. Now, this is again, not 100,000 but 10,000.

LAWRENCE KRAUSS: This is after 10,000 times, the whole thing, as you will see in a second, got completely uniform. You see the consent trick circle, it's like you stacked the dice.

TED SIMONS: What are we learning here?

LAWRENCE KRAUSS: We learned if you stir things at a certain rate, you’ll make them uniform. Now what good is that? When you are trying to pack things like grains, when you are trying to make micrograins that work and are more dense, how to close pack objects is an important thing in physics. Sometimes we do science for fun. Often we do. The question is what its practical application? This could be useful especially in zero gravity environments to try to figure out how to take microgranules and maybe make them dense enough to be used in the human body for medicine and other things. So now we know that one way to make them denser because the closest packing you get, it makes them the most dense. If there are gaps between them, they are less dense. So now we know that making them more dense by stirring them. Maybe useless. Might just be fun. You can try it at home. Take your YATZI dice and see if you can stir it.

TED SIMONS: Like a Rubik’s cube. What is exotonium? I didn't learn about this in chemistry in high school.

LAWRENCE KRAUSS: It didn't exist when you were in high school hundreds of years ago. It's a state of matter that had been predicted. Now I wanted to go to the physics of materials because that’s a frontier. Trying to use quantum mechanics to create new materials that may be useful in building or testing or censoring or computing is really the frontier of physics. It's an area we talk about next year, is trying to use quantum mechanics to make new materials that didn't exist before. Exotonium is a new material that exploits the weird aspect of quantum mechanics. If you have a material, you know, atoms are made of electrons bound to the atoms. If you excite them enough, if you have this material, excite them, kick some of the electrons out. Now it turns out in certain materials, those electrons can be freely flowing in a conducting van, and that’s what makes conductors and metals. If you take a particular type of material, however when you kick the electron out, what's left over? No electron. What is the absence of electron? Electron has negative charge so the absence of it has a positive charge. It acts like an antielectron. Turns out the electron kicked out gets attracted by the positive charge region and they combine together and form a new object called an ex-o ton. And that new object can have weird quantum mechanical properties. The question is if you do this enough, could you have enough of these exotons to bind together and condense into a new kind of solid material? This combination of electrons and no electrons, it sounds so weird that the electron could be bound to the absence of itself. But that’s quantum mechanics.
TED SIMONS: But what are the applications?
LAWRENCE KRAUSS: We don't know because we don’t know the properties yet. The point is that this is a new kind of matter that hasn’t been created before. It turns out the calculations, some say it's a wonderful conductor, some say it's a super conductor. Some say an insulator. We don’t know. The idea is, if you are playing around like we are doing a lot, let's exploit the weird properties. It was predicted that a new state of matter would exist 50 years ago but no one was able to create it. The new experimenters create a new type of,basically a microscope, to test to see, we discovered the condensed state of weird quantum mechanical objects. Now we can begin to do tests on it. They haven't done it yet. But by creating the state and validating the theory is true, we create a new state of matter and now we can find what the properties are. Maybe it's a new super conductor or quantum computers.

TED SIMONS: We'll get to that. You kind of jumped the gun a little bit.

LAWRENCE KRAUSS: I do that. I was trying to give you an in.

TED SIMONS: Sensories and technology and all sorts of stuff.

LAWRENCE KRAUSS: We have no idea. The sky is the limit. Once you have new materials, you find new applications for them.

TED SIMONS: There was a quote in a story about the people that discover this, makes sense it should have been there. It didn't make sense that it wasn't.

LAWRENCE KRAUSS: That's what's amazing. Quantum mechanics allows you to predict things, and it works, but you -- what would have been neat is if it didn't exist, in a way. As I said at the beginning of the program, we like to be wrong as scientists because there is something new you discovered. In this case the theory worked. You didn’t discover something new. You didn't discover that quantum mechanics breaks down. But we are now using quantum mechanics. Quantum mechanics, in a sense itself, doesn’t make sense because quantum mechanics are crazy as we talk about. In this case, we test to see if quantum mechanics still works. It wouldn’t make sense if the object wasn't there. It's one of the hardest things to see if it was there. We had to invent a whole new microscopy. It's weird to think that an electron could be bound to the absence of the electron. The reason the hole, as it’s called, has a positive transfer is when the electron is gone, all of the atoms in the material realign and effectively produces a small region that has a net positive charge and a small region, which is absence of the electron, binds. It's similar to the phenomena that produces superconduct activity which basically is an electron attaching to another electron which seems impossible.

TED SIMONS: When we are talking about quantum, it's hard to wrap your mind around. Give us the basics of what quantum mechanics is?

LAWRENCE KRAUSS: The basics, how long do we have?

TED SIMONS: Not much time.

LAWRENCE KRAUSS: There are many different ways to think about quantum mechanics, weird in all ways. The fundamental aspect of quantum mechanics, which is used in quantum computer, on the small scale things don't behave sensibly. Small objects, like electrons and atoms, behave in a way that seems impossible. For example, an electron is spinning. A top can spin in a lot of directions. In the instance it might be spinning this direction or that direction. Electron is spinning in all directions at the same time. I love the look on your face. It's only doing that if you don't look at it.

TED SIMONS: Yes. That's the one that kills me. The minute you see it, it's gone.

LAWRENCE KRAUSS: If you measure it, you force it to be in one of those states. What quantum mechanics tells us, the probability of when you make a measurement, you find it spinning this way or that way or in any which direction.

TED SIMONS: But if you look at and the ambiguity is gone, then what is it?
LAWRENCE KRAUSS: Then it's classical. It behaves sensibly. I look at you and you’re sitting in the chair. You’re never over there, as far as I can tell because you’re a classical object, and so am I. That’s why quantum mechanics are so weird for us. We experience the world on a classical level where things make sense. The lights are always in the same place, but not in many places at once. In the real world, things don't behave like that.

TED SIMONS: With that in mind, IBM has a quantum computer, big deal. Do I trust my credit card and all sorts of things with quantum computers?

LAWRENCE KRAUSS: Quantum computers are still in their infancy. It's promising and keeps promising, but there are leaps and bounds. IBM, the idea is that a regular computer, based on ones and zeros. You can all this stuff on your iPhone and everything with ones and zeros and they can do computations and everything else. And the one you can think of is electrons spinning up and an electron spinning down. There are a bunch of different ways. Or a magnet pointing in this direction or that one, and you store those numbers in a lot of different ways. The neat thing is, if you have an object that is intrinsically quantum mechanical, which is doing many things at once, and you don't interfere with that, don't observe it, then you can exploit the fact that it's doing many things at once, that quantum mechanical property, to allow it to do many calculations at the same time. That's a quantum computer. It's hard to do that because in order for a quantum mechanical system to be quantum mechanical, you can’t mess with it. The minute you look at it, interfere with it, you destroy what is called quantum mechanical correlations. It's hard to make a quantum computer based on Q bits, instead of bits which are ones and zeroes. Q bits are quantum mechanical bits and they have more information. If you can operate on the Q bits, you can do in principle, a huge number of calculations at the same time. While the computer is doing the computations, you don't interfere with it. In the end you make a measurement, your result. In the interim, you allow the computer to make many parallel calculations at the same time. The reason why I’m bringing this up is because I think this is part of the physics of the future. It may change everything but it's been shown, if you have a quantum computer big enough, you could take any large number and find out the fundamental prime numbers that make it up. Why do you care? That's one of the ways we encode the security of your credit card. We use this password encoding which is basically a large prime number that the bank knows about and if you decode it, you will know how to break into your bank account.

TED SIMONS: We have only a minute left. It seems to me, if I want to mess around with a computer, and it's a quantum computer, all you have to do is look at it.

LAWRENCE KRAUSS: Yeah. Well not quite look at it because looking at it is not enough. If you isolate the computer, and what IBM has been done is create a computer they claim is 50 Cubits. It may not sound like a lot because there are billions of bits in your iPhone. But 50 Cubits can be powerful. The problem is to maintain the 50 Cubits without being looked at and being disturbed, they last a few millionths of a seconds. So it doesn’t give you long to do the calculations. That’s the problem of quantum computers. But they are now putting it online so people can try to exploit the quantum reader. It may be the future. Stand by. That's perhaps how we should end the program. Before we end the program, I want to thank the people I saw in Prescott, Arizona at the bookstore who were there and raved about you.
TED SIMONS: Of course they did. Why wouldn’t they?
LAWRENCE KRAUSS: It surprised me, but they did.
TED SIMONS: Prescott is a lovely town.
LAWRENCE KRAUSS: It is a lovely town. The people were lovely.

TED SIMONS: Well I’m glad you a good time. We had a good time here. Thank you for everything you did this year. We look forward to seeing you next year. Very interesting stuff.

LAWRENCE KRAUSS: Have a happy new year.

TED SIMONS: That's about it. I'm Ted Simons. Thank you for joining us on this special science edition of "Arizona horizon." You have a great evening. ¶ ¶