Science Matters with Lawrence Krauss

May 20, 2015

Transcript:

TED SIMONS: ASU physicist Lawrence Krauss joins us each month to explain the latest in science news, including little things like the impact of newly discovered decay rates on the standard model of particle physics. Here now is Lawrence Krauss.

LAWRENCE KRAUSS: Sounded so good when you said it.

TED SIMONS: It sounds like I know what I'm talking about.

LAWRENCE KRAUSS: It's amazing.

TED SIMONS: Just a little bit. All right so we got rare particle decay discovered by our favorite - what are we talking about here?

LAWRENCE KRAUSS: The interesting thing is the large Hadron collider, discovered the Higgs particle, but it is doing more than that. There are lots of mysteries that we have not resolved, related to Higgs and what is the nature of dark matter and why are the forces the strength they are? They are looking for other clues that might lead us to the direction of trying to understand those things. One of those clues, they are producing literally trillions of particles, in order to discover the Higgs, they had to -- they have energies so intense it produces thousands of particles in each interaction. And among those trillions and trillions of particles, there are some that are produced very rarely and one particle called the strange B mesons--the B meson--there are--all the particles that make up us protons and neutrons are made up of things called quarks as we know them and protons and neutrons are made of quarks but there are other more exotic elementary particles made of other quarks. There are six types of quarks. The ones that make you and I up are called up and down quarks but there is charmed quarks and strange quarks and top quarks and bottom quarks and they can combine together to form new particles. There is this one kind of particle called the B meson which involved an anti-B quark the anti particle of B quark and either a strange quark or a down quark. They can combine together to form particles and they are very heavy and can decay. They decay very rarely than other particles. Our standard model that you discussed, allows us to predict exactly how they should decay. Now if we add new particles we have not yet seen or new forces we have not yet measured, those are going to change by a small amount the decay rates of these very exotic particles. What the large Hadron collider was able to do for the first time was measure decays of these very exotic strange B mesons and normal B mesons. And what was resulted is kind of interesting and intriguing. Because the strange B mesons decayed exactly as they were supposed to in the standard model, confirming the prediction. But the non strange B mensons actually decayed four times faster than they would in the standard model. That's one of the potential indications that maybe some of these ideas, like super symmetry and other things that are meant to describe dark matter might be true. So its attempting discovery--the problem is, so few particles were measured, that four times the expected rate is allowed with the kind of statistical likelihood that we don't accept. So one out of a thousand times that can happen by random. That may sound rare. But in particle physics, unless you can get one in a million times or better, then we think it could be a random event. So we have to--the large Hadron collider is we talked about is now turned on again it's got much higher energy. It's going to be producing many more of these particles and we can check, but it could be the first tempting indication of some new physics that may reveal the explanation of dark matter, super symmetry, life, the universe, everything.

TED SIMONS: I was going to say, deviation in this case might be okay because it could lead to bigger, better things.

LAWRENCE KRAUSS: Deviation is always okay in a sense, because being surprised is what science is all about. And so we look for clues that tell us not just that we're right, but sometimes that we're wrong because it tells us we know we don't have a complete theory of everything. We know there are lots of open questions. We know at some level the standard model must break down. The question is where does it? And when we can find that, it may answer other important questions including the nature of most of the stuff in the universe.

TED SIMONS: Interesting. All right something else that happened here of note is a new effort to reconstruct the history of life.

LAWRENCE KRAUSS: Yeah, since I run the origins project at ASU, origins are of great interest. Look, we know a lot about evolution. We know about the evolution of species and we can trace back to the our earliest -- fossils almost 4 billion years old. Sometime between the time the earth formed 4.5 billion years ago and the time the single-celled animals or microbes, if you wish, that are the precursors of modern life form it was a large chain some coming from non-biology to biology, before cells, metabolism or the replication that RNA and DNA is all about. So the question is how to find out what happened in the interim, which could have been 500 million years of molecules rearranging until they discovered what is essentially the secret of life. You might think it is impossible if we don't have fossils to go back to that time, and a new study is kind of interesting because what happens is that obviously proteins are essential part of life. They operate--they basically operate the metabolism that governs our existence, but they also form the basis of complex molecules that later on build up the molecules that govern life. They're made of things called amino acids, and there are about 20 of them that form the basis of most of the proteins in life. What was recently discovered is that you can look at the different kinds of amino acids, and there is one, tryptophan, which makes you sleepy after Thanksgiving meal, and that--so it is in turkey, which is kind of rare in all of the proteins that have been made. Since it is kind of rare, people thought maybe it was kind of the last amino acid that was incorporated in whatever it was that eventually created the modern processes that govern life. And a new study basically demonstrates that that is the case. It looks at two proteins that actually help RNA form amino acids, and two of them are slightly different. One makes tryptophan and another one makes something else. They realized they originally formed from a single protein before it had diverged and they worked back to find the structure of that and, in fact, discovered that there was no tryptophan there. So, the early proteins that were first forming the metabolism of life didn't have tryptophan. Tryptophan is a really late entry. Now what these people can do is try and look at other processes that involve metabolism or cell formation and look at those kind of proteins and see if they involve tryptophan. If they do, then well, they happened fairly late. If they don't, they happened early. We may be able to get the life history by using this as a marker. It's a fascinating development.

TED SIMONS: It really is. It makes sense for goodness sakes. And is this what we are talking about Paleo genomics?

LAWRENCE KRAUSS: Yeah, all of these new fields Paleo genomics, geophysical biology all of these fields are coming together which is by the way why ASU is so wonderful. Because we're based not on 19th century disciplines but putting things together. Like the Biodesign Institute, where we bring physicists and geologists and biologists together to try to answer these fundamental questions.

TED SIMONS: We talked before the show, this book, The life by Richard Forte, that is considered a pretty good book right?

LAWRENCE KRAUSS: I enjoyed it.

TED SIMONS: I'm reading it now.

LAWRENCE KRAUSS: I learned some things from it early on and I am hoping that you are now.

TED SIMONS: Well, we'll see about that. Okay before we get out of here now, I understand that the Andromeda galaxy and our milky way are on a collision course.

LAWRENCE KRAUSS: Yeah, that's been known, I think we have even talked about that before. Well, they're much closer than we thought in one sense. We know that the center of the Andromeda galaxy, which is the closest large galaxy from us about two million light years away, it's heading towards us right towards you right now and in nearly 4 billion years, that center and the center of our milky way are going to collide. So we kind of thought okay well the collision isn't happening for 4 billion years. But what was just discovered like our galaxy is about 100,000 light years across and so 2 million light years away is pretty far compared to 100,000 light years 20 times exactly in fact and so it's far away. But now by looking at the light coming from distant QUASARS through the Andromeda galaxy looking for absorption what has been discovered is that Andromeda has a halo that's almost as you can see almost 2 million light years across, which is the distance to us.

TED SIMONS: Uh-oh.

LAWRENCE KRAUSS: So there is gas from Andromeda if you wish, that has already started to collide with the milky way galaxy. We're much closer than we thought. And maybe our galaxy has a big halo. We can't see it. We can't--we're lucky to be able to look at Andromeda and look through it but we can't look through our own galaxy.

TED SIMONS: Are we breathing Andromeda gas?

We could indeed be breathing Andromeda gas right now, you and I.

TED SIMONS: Now, Quasars play, as you mention a big part in this. Explain.

LAWRENCE KRAUSS: Quasars are the brightest objects in the universe we think they're super massive black holes that are eating up stars and emitting huge amounts of radiation. We can see them across the other end of the universe. Here are some pictures. We can see them literally the farthest objects we can see, back to when the universe was less than a billion years old or around a billion years old. They emit so much light, what is in such a neat position because there are lots of Quasars that we can look at that are near Andromeda and then we look at the light that comes from those Quasars and see how much is absorbed, if it's hydrogen gas there, it absorbs a little light, and the more hydrogen gas there is the more light it is. So we can't see that halo of Andromeda directly but we can see the light absorbed by these Quasars and that's when we know suddenly Andromeda is a lot fatter than we thought

TED SIMONS: It's like a process of elimination a little bit in some senses. Isn't it?

LAWRENCE KRAUSS: That is what science is all about. We eliminate the stuff that is wrong and what remains is what we think is the truth.

TED SIMONS: And just for you we have a visual representation of what is going to happen. Once in four billion years, when these two galaxies collide.

LAWRENCE KRAUSS: You'll look up to the sky in about 3.9 billion years, you look up in the night sky, and you'll see if you are in the southern hemisphere where you can really see the milky way where I just came back from. You will also see the Andromeda galaxy. But the good news is, when they collide, not much will happen. Hardly any stars will hit each other.

TED SIMONS: Really?

LAWRENCE KRAUSS: What will happen is our galaxy will no longer be a beautiful spiral galaxy it will be a big fat elliptical. But other than that--and the beautiful view in the night sky there won't be many catastrophes so for those of you worried about what you are going to do in four billion years, don't worry now.

TED SIMONS: All right so we basically got the particle decay, we've got the history of reconstructing life and we've got Andromeda--the next time you show up next month... I never ask you this but do you have an idea of something bubbling out there that is going to explode?

Sometimes I do. Sometimes I have some suspicions about what is going to happen. But most of the time I'm surprised and I always tell people, they say, "what is the next big thing?" You know what I say, I say, "if I knew, I would be doing it."

TED SIMONS: All right. Well we will let you go on your way and give it a shot. Always good to see you.

LAWRENCE KRAUSS: Take care. Bye-bye.