Krauss on Science

Dec. 10, 2013

Transcript:

Ted Simons: Coming up next on "Arizona Horizon." Physicist Lawrence Krauss joins us for a look at the latest in science news, including a comet that flew too close to the sun, and the possibility of an ancient lake on mars. Science talk with Lawrence Krauss next on "Arizona Horizon."

Narrator: "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. Every month renowned physicist Lawrence Krauss joins us for the latest in science news, and tonight we'll hear about comets, life on mars and things that shake up the family tree. Here to explain it all is Lawrence Krauss. Good to see you.

Lawrence Krauss: It's good to be back in this holiday season.

Ted Simons: And good to have you for the entire show. We're not going to rush you out of here so the great mysteries of the universe are not being compromised.

Lawrence Krauss: And we have a black board for the equations?

Ted Simons: You go right ahead.

Ted Simons: Let's start with this ice on comet, we were so excited, and we could not wait to see it go around the sun and come back. It went around the -- what happened?

Lawrence Krauss: It's hard to predict what's going to happen. How many times have you been disappointed by comets. It's going to be great, and we don't know, it's one of those things, that, that -- it was very bright when it was far from the sun, and that's what gave people a lot of hope that it would, it might give wonderful fireworks S. came around the sun and passed by the Earth. It was -- interestingly enough, it was one of the observations headed by a group at ASU, of the mars reconnaissance are a bitter that turned its cameras towards the, the comet when it flew by mars, and saw that it was less than a half a mile across, and that meant it was small. And then it would go close to the sun, and a whole slough of, of different instrument, images of the comet, and everyone was waiting with bated breath to see what happened when it came close to the sun, and what happened is it sort of disappeared, and ended with a whimper rather than a bang. It was a small comet, very close to the sun, and comets too small, don't have enough self gravity to hold them together under the heat of the sun. And with the large gravitational field and the heat, and this one, basically, broke apart. So it died, and then it came around the other side, and you could see it again. And people thought, maybe just it disappeared am but that was the pieces broken out, so it broke up. That's a disappointment. If you like to see things under the night sky, and the big comets are amazing, but it's not so disappointing for scientists because as it breaks up, and there were so many, this comet has been studied by more instruments than any other in history, and so many were focused on as it was breaking up and shining on the sun, that we can learn a lot about the competition and, and since comets are really, really messengers of the beginning of our solar system, this comet came from the ort cloud, which is . trillion miles from the sun. It was formed when the solar system formed. So this snowball contains the primordial water and stuff, the same stuff that seeded the Earth, so if we can see the light, before it died around the sun, we'll be able to learn the materials that came from it, and its composition, and learn about the primordial stuff.

Ted Simons: And that kind of gets you a bit here. This was some odd billion years old, and it goes towards, and then it's gone.

Lawrence Krauss: You fly too close to the sun and you are gone. That's happened since the Greek myth.

Ted Simons: Isn't it sobering to think about something that old gone?

Lawrence Krauss: Think of when the Earth goes, we'll be billion years old and we'll be gone. Most comets miss the sun. Some of them go right into it. Remember the comets that hit Jupiter, they get absorbed. Fortunately most comets hit Jupiter because that's what made it so big, otherwise they would have hit the Earth. And Jupiter ate them up, which is why it is , times the mass of the Earth. It's, for strong immerse, it's fascinating to watch the death of something like that because you learn a tremendous amount about it.

Lawrence Krauss: It's not too happy for, well. The comet didn't care.

Ted Simons: Right.

Ted Simons: And so it has been in orbit, doing something for . billion years?

Lawrence Krauss: Yeah, it's on the outer -- there is a huge amount of material, in the outer part of the solar system. Some of which, which was there as a solar system collapsed. And other, other of which was shot out by Jupiter, as it grew, the gravitational pull, sometimes it kicks them out and sometimes in. There is a tremendous number of objects in this ort cloud that are orbiting around and have been around since the beginning of the solar system, and just like the planets orbit the sun. What happens is for reasons that we're not % certain of, some gravitational probation, it gives it enough gravity to change the orbit and cause it to head towards the sun, and then it's a comet. And, and those snowballs, sometimes heads towards the sun but more importantly, as I think we talked about in the earlier program, some of them hit the Earth, and we think that there is enough comets that hit the Earth, and they are large snowballs, over the history, to have produced all the water in the Earth's oceans. So, they are very important. And because there are organic materials on comets, they may have seeded the Earth and, potentially, other planets with the raw materials necessary to create life. So, they are incredibly interesting.

Ted Simons: Boy, I just -- . billion years, we go to Thanksgiving and you are over with and history and gone.

Lawrence Krauss: Everything, you know, at least it went, it went out with a bang.

Ted Simons: So is ice on dead?

Lawrence Krauss: It's dead.

Ted Simons: Ok.

Lawrence Krauss: And you know, a week ago, it was probably %, but I was look at the website, and they said it's gone.

Ted Simons: So it's not hiding in the dust or hiding behind a flare.

Lawrence Krauss: It was probably emitted as it broke off, so it's gone, and we'll have to wait for the next one.

Ted Simons: All right. And what's this business about the possibility of an ancient lake on mars?

Lawrence Krauss: Well, and it's a perfect segue because it was probably created with a large impact, and in fact, it was, with a large impact. In a crater. It was about billion years ago or so and, and, and, of course, NASA knew that might be a good sight for lake beds, it looked at other places and the other rovers and discovered places on mars that they thought there was liquid water in, and I think it was opportunity that found a spot, and it was more sulfuric acid than water, but this looks like, from the sky, we could see from measurements, like there was clay. Now, clay forms at a lake bed so that's why, why the, the Rover, went down and landed in that crater to look at that lake bed. And what's, what's been discovered is, in fact, while it was discovered a while ago, that on the surface, if you looked at the materials, it looked like the materials you might see here in Arizona by a stream. Materials are weathered by water, and it looked like liquid water flowed. There is clay directly measured there. And now, it's become clear as the Rover drilled down about five centimeters into the martian rock, that it not only is clay, but it looks like from the chemicals there, that, in fact, it was a lake bed, all the, the rock structures are just like, like a lake bed here on Earth, but are also, what's interesting, is it has materials like carved in an oxygen and phosphorus, that, that suggest that there may have been organic, materials there. Now, from measuring this, you can suggest the lake bed was maybe large. And, and according to NASA, would have existed for at least or , years, that may sound like a long time, but from the point of view of the evolution of life, it's not so long. But, that's at least. Some people argue it could have existed for millions of years or tens of millions of years. It was fairly shallow lake bed, and what's also clear, is that, is that mars, even though in the early history of mars, in the first billion years, remember, this lake bed was created about billion year ago, when mars was a billion years old. Mars was much hotter and wetter than it is now. But, from looking at the material sort of brought into the lake bed by water, streaming water, that material didn't get, didn't get weathered like it normally would have. That suggests it was cold, so this might have been a frozen lake bed, which thawed, so mars was hotter and wetter than it is now, but not a Shangrila, it looks like it was cool, so there is a lot of questions, what I was just reading, which is interesting, is that -- and this is preliminary, but there is evidence of carbon, which is the basis, so the question is, is it due to organic molecules or Carbon Dioxide. A recent test heating it up suggests it might be due to organic, materials. So you have water. And/or organic materials. And that gets people excited. Now, where does the materials come from? Life or the comet, from the comets? And the answer, we don't know, but if you look at the organic material, that the comets have bombarded, if he upper level, the level of carbon that's measured there, could have come from the comets within a factor of two. Or it could have come from organic materials. So, they are going to -- there have been some proposals for ways to, actually, look for these materials directly, in this lake bed. It's, it's an open question. I have to say, I'm a little pessimistic because, you know, water, organic materials, sounds great, but if you look at where life first formed, probably deep in the ocean beds because you need more than that, a source of energy. Life requires energy to, to, to operate, and there is some, some weird organisms that exist a mile underground that use the, the different elements in the rock as power, and it's, it's -- that's, that's pretty hard -- that's probably pretty hard to do. The simplest way for life to have developed was where there was a lot of energy and power, and the lake beds, and the deep ocean vents where the hot, rich materials coming out with lots of, of hydrogen, and that was a good place for life to start, if this was a lake bed, there would be water but not that source of energy. So, but, one last bit, the lake was around about . to . billion years ago, somewhere in that range, and after the, the impact, meteor impact that caused the crater. And that's just around the time that life evolved on earth. The oldest fossils on Earth are . to billion. So here's a liquid environment existing at the same time as life was evolving on earth, and that gets people excited. From my point of view, the greatest likelihood of finding life in that, in that, or existing life, but extinct evidence of organic materials, might be if the microbes on earth were knocked out of earth by some impact and, and landed on mars because I think I have told you before, we get rocks from mars all the time, and a bit more rarely, mars gets rocks from Earth, from, from impacts, and there were more impacts occurring in the first billion years, so, maybe the Earth polluted mars, and that was an environment where they said we'll see, it's an open question, and it's exciting as a big if. We might be as disappointed by it as we were the comet --

Ted Simons: This is all very fascinating but one last question on this, so comet, perhaps, hits mars, and lake is formed, and a couple hundred thousand, whatever, of years, what happened to the lake? Where did it go and what happened?

Lawrence Krauss: Well, mars got cold, and the water, from the surface, because mars is smaller than the Earth, evaporates.

Ted Simons: Ok, so, basically --

Lawrence Krauss: Or, there is some water that, that seeps down, and there is evidence of water underneath the martian soil, so there is water on mars, but, any large lake beds, would disappear, and mars is too far and smaller than Earth, so it cannot hold onto what are volatiles. It evaporates in the atmosphere.

Ted Simons: So no aquifer or cloud.

Lawrence Krauss: Not now, but, you know, billion years, there could have been, and you know, and we don't know. And it's all could have, but that's why we send things there to learn, and maybe one day I will say, a creepy crawly thing --

Ted Simons: Right.

Lawrence Krauss: But I would not hold your breath.

Ted Simons: As long as we get to interview the creepy crawly. >

Ted Simons: New DNA throwing a lot of people for a loop here because now, there could be another prehuman -- what's going on?

Lawrence Krauss: You know, this falls on the last program, I think, that we're discovering a lot about our lineage, and all the time and, and as I said, in the last program, you know, we're, we're working on little, little tidbits, the example I used was, if you found -- if, a archaeologists found the remains of a basketball player from Arizona and me, they might say we're two different species because unless we happen to be in the same cave or the same house or whatever, when we got hit by asteroid or a comet, who knows, but, and so, it's really hard to make generalizations, if you are working with sparse data, we're getting more data all the time, what's interesting about this observation is that it throws things up again and flies in the face of conventional wisdom. So, a group in Germany a decade ago began to be almost like, Jurassic park, to drill into the bones of fossilized remains and extract the DNA. And begin to, to build up an impression of the DNA of these ancient comets, and in fact, essentially, they almost, the genome of the Neanderthals has been sequenced, ok. Now, what was discovered in a cave in Siberia from about to fifty to sixty thousand, years ago was DNA from a finger of a young girl at the time and, and it did not seem at all like the DNA of, of the Neanderthals. I think it was in Siberia, so these, these, were called deviants, and they thought they were connected to the common ancestor that connected them to humans, like Neanderthals are our cousins, and that they were another recent species, separate. Now, the problem is, a new, in a cave in Spain, the oldest DNA recovered, , years old, but it's in Spain, not Siberia, which felt that they went over to Siberia, and the Neanderthals weren't, and that's how they sort of -- they diverged from the common ancestor because when species are separated, that's how they evolve and diverge. So, they were way over there, and the Neanderthals were in Europe, and the homosapiens were in Africa, and eventually they left Africa and all the other guys die out, maybe we killed them. And they went extinct. Here in Spain where the Neanderthals are supposed to be is a ,-year-old bit of DNA. When it's sequenced it looks like the denisivants. A lot more like that, than the Neanderthals. So the question is, what gives here? And, and there is lots of possibilities, while there was DNA in the common ancestors, and a lot of them died out and stayed with them and died out in the Neanderthals, so maybe there was a common ancestors or a new species that looks like the others, or maybe we all share that, and it just -- it indicates that, that the, the conventional wisdom that they are somehow the idea that the Neanderthals and others were separated and their DNA is distinct is not right. And it's amazing you can do this, you have to worry a lot about when you are looking at ancient DNA because bacteria and other things get in there, so you in a Ed to make sure that you are not contaminated by, by that, and they have been able to do that very well in Germany and, and so this seems definitive, and the means are, ancestry is more complicated and interesting than we thought. We're always at the edge of the knowledge, and it doesn't suggest that we don't have a common ancestor with these people, it does, all that works out. Evolution happened and we have these, as our common ancestors just as we have worms as our common ancestors, but the details are being worked out. And refining things and being wrong is what science is all about because we learn new things, and so, we'll just keep trying.

Ted Simons: So we don't know if this is a separate species. All these are kissing cousins.

Lawrence Krauss: They were, one thing we know is we were all kissing cousins. There is evidence that homosapiens, Neanderthals and the Deviants interbred. I remember thinking species are things that are separated, and they cannot breed and produce viable offspring, that's not true, not the definition of species. It's much more complicated because of DNA measurements, so, humans did interbreed with Neanderthals, and denisivants. and maybe there was a lot of intrigue going on.

Ted Simons: Probably a soap opera, and before we go, the higs.
Lawrence Krauss: Today is December , you know what happens on December ?

Ted Simons: The nobel prize comes out.

Lawrence Krauss: It's given. It comes -- December is the big -- handed out as a big party, an amazing event, and today, the prize is given to Peter higs for the proposal of the higs, one of the greatest, part of the greatest edifice created, the standard model, and so we're celebrating that today, so I thought that we should talk about it, and I thought it would be good to -- the standard model is a much more well-defined theory than our understanding of our human ancestry. Every experiment has been done for years, and agrees with this incredible theory that describes three of the four known forces of nature. But, there is still a lot that we don't know, and while we are celebrating this cap stone of the standard model, the discovery was just the beginning. [Inaudible] was shut down and is being upgraded

Ted Simons: What is that?

Lawrence Krauss: The largest head rock collider, the collider, to be upgraded because it was designed to be an energy about twice the energy being used, but they really couldn't get it working, and a higher luminosity, which means -- a higher luminosity, and there was only a few hundred events that we could classify as the parcel events, and you don't have enough to say what's going on. But the machine is being upgraded and being turned on, and the real mystery is why is it there? It's there, it's required, but why does the standard model have the properties it has and the interaction weaker than the electro-magnetic interaction but stronger than gravity? It depends on the scale at which the higs mass is, and we don't know why it has the mass it has. The evidence was suggesting it should be in this range but it's a free parameter, and very perplexing why the forces are separated out. And we think the reason is that there is a bunch of new stuff happening at that same scale. A whole bunch of particles. And as well as we still are not certain if it's the only higs in different models that we proposed, that may explain this, there is more than one. So we want to measure the property by not creating of them but millions of them to see what the properties are but look for those particles, so when the accelerator turns on, in , we're going to be waiting because many of us thought that we're more interested if you wish in the other stuff, because the higs was predicted to be part of the standard model, and it's exciting to discover it to tell us we are on the right track, although as I said earlier I would have been more excited if it wasn't there because I am excited for it on the wrong track because it means there is something more exciting to discover. But the questions about why it's there hinge on this other stuff. And so discovery of the higs has opened the door to what we think may be a vast new world, like opening the, the, as I said once, open the amore in -- the CS Lewis story, Narnia. You discover a new world in there, when we turn on the collider, we could discover a new world, and some could argue this relates to the possibility that there are extra dimensions in nature. I would not bet on it but there is a large number of people who say there is an extra dimension, and actually we'll see particles smashed together and disappear. Into an extra dimension and that would be wonderful but it won't happen.

Ted Simons: The bottom line, you need to get the collider, and the particles hitting each other at the super-duper speeds. That's the only way you can find it.

Lawrence Krauss: If there is any other way, a cheaper way we would do it, but it's amazing, and I think I have said it before. This is the most complex machines built. kilometers around, super conducting, tons of liquid helium, operating in a temperature colder than, than, than outer space. With a vacuum, that's more rare than outer space. There are fewer particles in that tube, and it has to work over miles with a magnetic field bigger than the magnets we use for MRIs or anywhere else, if they were not super conducting, they would use more power than you could produce in Europe, but super conducting magnets, don't use power. So, it's just incredibly complicated, and it is still amazing that it works.

Ted Simons: And quickly now, you mentioned all of this power that would be needed, still a lot of power is needed, what about data? Where do you keep the data and who looks over it? There must be mountains of this stuff?
Lawrence Krauss: More than that. That was another challenge for sern, every second it is running, , terrabytes of data, is, is being generated, so there is more data being generated every second than in all the libraries object Earth. So, what that means is, and the only way you can handle this, throw it out. So you need to have smart computers that can look and say, that does not look interesting. We're only going to keep, you know, one part in a million, which is enough to, to pile the biggest computers, the largest computer network ever being used, just to look for, for this stuff, which ultimately will tell us why we're here.

Ted Simons: And thus, the nobel prize in physics.

Lawrence Krauss: Exactly.

Ted Simons: All right. And it's great to have you here, and good to see you again, and we'll look forward to next month.

Lawrence Krauss: I'll see you in the new year.

Ted Simons: Sounds good.

Lawrence Krauss: Great.

Ted Simons: And that is it for now, I'm Ted Simons, thank you very much for joining us. You have a great evening.

"Arizona Horizon" is made possible by contributions from the friends of Eight, members of your Arizona PBS station. Thank you.