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Science Matters with Lawrence Krauss

Airdate: September 22, 2015
Join Arizona State University Lawrence Krauss as he gives his insights on the latest science news.

Guests:
  • Lawrence Krauss - Physicist at Arizona State University
Category: Science

View Transcript
TED SIMONS: Coming up next on "Arizona Horizon," we'll get the latest science news with ASU physicist Lawrence Krauss. And we'll meet the Navajo nation's new poet laureate. Those stories next on "Arizona Horizon."

VIDEO: "Arizona Horizon" is made possible by contributions from the friends of eight. Members of your Arizona PBS station. Thank you.

TED SIMONS: Good evening and welcome to "Arizona Horizon." I'm Ted Simons. A new complaint was filed today against corporation commissioner Susan Bitter Smith. A group called Public Integrity Alliance filed complaints with the Secretary of State's office and the Clean Elections Commission, claiming that Bitter Smith should be removed from office due to conflicts of interest. The group claims that Bitter Smith is violating the law by lobbying for Cox communications and other telecommunication companies that are regulated by the commission. Bitter Smith has said that there's no conflict because she only represents cable interests, which the commission does not regulate. Programming note: Corporation commissioner Bob Burns will appear with us tomorrow night on "Arizona Horizon." Best selling science writer and world renowned physicist Lawrence Krauss appears on "Arizona Horizon" each month to provide insight into the latest science news, which tonight includes a new theory on black holes and new evidence of an early human ancestor. Here now to explain it all In easily understandable terms is Lawrence Krauss.

LAWRENCE KRAUSS: Thank you.

TED SIMONS: How you doing?

LAWRENCE KRAUSS: It's good, always good to be here to talk to you about science.

TED SIMONS: That's good to have you here to talk about science. Let's start with one of my favorite topics because I still don't feel like I quite have a grasp of this.

LAWRENCE KRAUSS: I know what you are saying.

TED SIMONS: Steven Hawking.

LAWRENCE KRAUSS: Is he your favorite topic?

TED SIMONS: He thinks he has a new theory on black holes.

LAWRENCE KRAUSS: Yeah, I know you are thrilled about black holes and it's good to return to the subject. Even though it's not really news. Because I doubt this much of a new theory but they are so confusing. Because a black hole is an object as we have talked about before that's heavy enough, basically so dense that light can't escape from it. The escape velocity is greater than the speed of light so nothing can travel faster than light, nothing can get out. That's why they are called black holes. OK?

TED SIMONS: Right.

LAWRENCE KRAUSS: Now, there's a bunch of problems, well, there's Hawking became famous for discovering when you add quantum mechanics in the mix things are a little stranger because although nothing can get out classically with -- quantum mechanics is so weird you can have particles spontaneously appearing and disappearing in empty space. You get a particle, antiparticle pair that would appear outside the black hole. One particle would fall in, another would go out and the black hole would radiate by something called Hawking radiation. You are looking at orbits. That's the classical pictures. When objects fall into black holes they stay there. But when you have quantum mechanics, the black hole can actually evaporate. But the real problem, and this is what Hawking first outlined 40 years ago, a real problem, is that if stuff falls in, and you lose all information about what happens, what fell in because you can never see in there, if the black hole radiates away and disappears what happened toll all the information? Whether they were two Volkswagens or one Cadillac? That violates the laws of physics. They say in principle even though it's almost impossible to in practice, to actually get the information, if I light this paper on fire, in practice I could never get the information. But in principle, if I can somehow get out the light and soot and everything else I can get the information. So this is what's called the information lost paradox. What happened to the information? And what Hawking is described just recently an idea that a number of people talk about, including me I must say to be honest. What happens, what's called the event horizon of a black hole, the event horizon is just some point which when you are inside of it you can never get out. It's not as if you see a sign post when you fall towards the black hole. Once you are inside the event horizon you can never get out. Inside of that the escape velocity is greater than the speed of light. Outside it's less. If you turn on your engines you could avoid the black hole. Strange things happen at that event horizon. If I was looking at you falling into a black hole.

TED SIMONS: Right.

LAWRENCE KRAUSS: I wouldn't want to see that. Before you turned into spaghetti as you got stretched and destroyed, what happens is because space gets so contorted there, time slows down. If I am watching you. And if I am watching you fall into a black hole, you actually freeze at the surface. I will never see you fall in. Because time and space are affected by gravity. At the surface of a black hole, the event horizon, all sorts of strange things happen. When Hawking and some others have recently suggested is perhaps all even though the particles fall in, all the information about what fell in is actually trapped on the surface of the event horizon. Even though there's a lot of stuff on the interior all the information is trapped on the surface. That idea goes back a little bit because have you ever seen a hologram?

TED SIMONS: Yes.

LAWRENCE KRAUSS: They are two dimensional plates like pictures. But if you look in them you see the three dimensional image. So on a two dimensional surface is stored all the information of a three dimensional image. People are suggesting that there's this something called a holographic principle that some may say everything that fell in the black hole gets stored on the surface. The problem is, right now it's all talk. And Steven likes to think about this subject which he created in terms of elucidating the problem a long time ago. The problem hasn't been solved. We are still very confused about what happens on the surface of a black hole. And where that information goes. And we don't have the slightest idea.

TED SIMONS: Again, we were talking information. Talk about, A goes in. But when B comes out, it's still part of B but --

LAWRENCE KRAUSS: No, no, not even part of A. Let's say you and I fall in the black hole.
TED SIMONS: Right.

LAWRENCE KRAUSS: Eventually it radiate emitting all sorts of elementary particles that will have no record of your falling in or my falling in and there will be no, and that violates the laws of physics. We still don't know how to resolve that problem.

TED SIMONS: Right.

LAWRENCE KRAUSS: Information cannot be lost in quantum mechanics.

TED SIMONS: But it can change.

LAWRENCE KRAUSS: It can change and the question is, it certainly can change but there is as much information coming out as what fell in? And it turns out if a black hole radiates by Hawking radiation it would be like an oven element. It radiates as a black body and there's the least information in that of anything. In fact, a black body distribution is described by one temperature. Its temperature. You have got information on millions of planets and stars that may have fallen into the black hole and in the end you come out with one number. That's what you would call a loss of information.

TED SIMONS: All right. Well, so Steven Hawking has kind of a new theory.

LAWRENCE KRAUSS: He suggests it does. He hasn't published it yet. We are still very confused. The bottom line we will get to talk about this again.

TED SIMONS: Good. Let's talk now about the idea of the Hadron collider which we talk about a lot. We like that machine. It's a wonderful machine.

LAWRENCE KRAUSS: The biggest machine humans have ever built. Most complex one.

TED SIMONS: Tiny bits of matter, now you are saying they may have found bits that recreated the first moment was time?

LAWRENCE KRAUSS: Not just the first moment was time. What's really exciting and just at least exciting to me and what was just announced this month is the great discovery made July 4, 2012, was the discovery of this particle calls the higgs particle. The last bit of particle physics. I am finishing a book on this subject this week, in fact. It is the reason you and I are here. Because the higgs particle gives mass to on the ordinary matter. There's a field throughout space and waves move through it, we act like we have mass. If that wasn't there we wouldn't have mass. Nothing in this room would be around. So it's really responsible for our existence. And for 50 years it's been predicted on July 4, 2012, it was claimed to be discovered. But all that was discovered was a little blip and that detector that looked like it might be higgs. What they just reported was that it is a higgs. Namely all the property was how it decays, what particles it couples to have been now explored and examined with relatively high accuracy and they are exactly what's predicted. And so this really is the particle that is given you and I mass. I don't often have visual devices but I want to show how complicated this is. Here's the paper. OK? And that's the paper, seven pages long. This is the author list which is 18 pages long, thousands of physicists and this is the list of institutions, just the institutions of the authors. It's seven pages long. These are the most complicated experiments humans have ever performed. They require thousands and thousands of people working for years and it's amazing they can even extract this information.

TED SIMONS: Again, the collider is the reason for this. Because it basically had what, a couple lead nuclei, I don’t know --

LAWRENCE KRAUSS: They collide lead but what they do to look for the higgs particle, it's the anti, what is the guys that used to make lead into gold?

TED SIMONS: Alchemists.

LAWRENCE KRAUSS: They are anti-alchemists. They often shoot gold atoms together and make lead. These are complicated collisions that are happening billions of times every day. And each collision is producing thousands of particles, more information comes out of each collision in data than is stored in all the world's libraries and yet they can find the higgs and I think, what they do look at higgs is shoot protons at other protons but they accelerate them at 99.999% the speed of light into each other. And it's amazing. Even in those collisions thousands of particles are produced. And of the billions and billions and billions of particles produced, we probably have a few hundred higgs that have now been produced.

TED SIMONS: But what I read was that they also found this plasma, this idea that this was a first moments of history. The big bang.

LAWRENCE KRAUSS: OK. In a sense, yes. Because with protons, you can't do it. If you shoot heavy atoms and they smash at high energy then you heat the whole thing up to literally trillions of degrees. And that configuration of material is just like what the universe looked like on small scales when the universe was a millionth of a millionth of a second old. They were recreating conditions of what the universe looked like when it was a millionth of a millionth of a second old and confirm, allows us to test our ideas of not only the big bang.

TED SIMONS: I hope they are not creating new universes.

LAWRENCE KRAUSS: Would they create black holes that destroy the world? We are still here talking. Proof that didn't happen.

TED SIMONS: We have one more thing to talk about. This is a new species that looks like it's another ancestor of yours.

LAWRENCE KRAUSS: Or yours. It's got a very small face. Anyway, it's an interesting discovery because, of course, we have talked to this program about new discoveries made all the time. Because the fossil record is growing but this is a really romantic one in a way because this discovery was made of what looks like a totally new species of hominid, that's what based on the largest collection of fossils, 1500 that have ever been detected from a single species. We may know more about this species than any other. We don't know the age. It's probably around 2 million years old. It's probably one of the earlier homo species. Homo sapiens are a genus and this is an earlier version and it's been called homo Naledi. It has long slender hands. Relatively tall, about five feet. But its brain is the size of an orange. So small that it's smaller than the later species like homo erectus and all of those things. We think it's very early. It may be the first member of our species if you want. And the neat thing is, all these skeletons were discovered over 100 feet down in a cave. It looks like they buried them. It looks like the species somehow brought these people toking buried. To get there you had to go through a crack seven and a half inches wide. They had to advertise for spelunkers and if you can look at those images they had to be women because they had to be so small they could fit through this narrow crack. One of the women said it literally was the most dangerous enterprise ever undertaken.

TED SIMONS: They crawled all the way down.

LAWRENCE KRAUSS: They had to climb up 100 meters down. Down 30 meters. And found all of these skeletons.

TED SIMONS: And this really is a tremendous find, is it not?

LAWRENCE KRAUSS: It's the biggest find in probably the history of looking at hominids.

TED SIMONS: It's dangerous when I'm reading but I read that it's, they are very human-like in the sense it looks like they buried their dead. That separates us from the other animals.

LAWRENCE KRAUSS: Yes, maybe. But we don't know that. There are all these skeletons down there. They may have buried their dead or you know what could have happened? Some group was exploring this cave. And maybe there was the mouth of the cave collapsed and they all died. We don't know for sure. That they buried.

TED SIMONS: But they said there were infants, kids, there were young adults, older adults.

LAWRENCE KRAUSS: They may have traveled in a tribe. I'm just you got to be skeptical at this point. Until we learn more it's interesting but if they did bury their dead these are maybe 2 million-year-old fossils. It if it really is true it says something remarkable about the homo species.

TED SIMONS: About five feet tall, feet like ours. Hands I think were a little bit different than ours. Correct?

LAWRENCE KRAUSS: A little narrower and bending in a slightly different way. There you go.

TED SIMONS: Is that feet?

LAWRENCE KRAUSS: That's the feet and that's a modern human foot and their feet. They did walk upright.

TED SIMONS: To me it looks very similar.

LAWRENCE KRAUSS: No kidding.

TED SIMONS: I am not a paleontologist which is one of the reasons I am not a paleontologist.

LAWRENCE KRAUSS: It's exciting news. Exciting news with this. Exciting news regarding Steven Hawking and his idea of black holes. Exciting news about the higgs being kind of confirmed.

TED SIMONS: Discovered. Now have to find out why it's there but we now know it's there. Pretty unambiguously and it gives us a chance to talk again.

LAWRENCE KRAUSS: You help us make sense of all this stuff. Good to see you again. Thanks so much for joining us. Appreciate it.