Arizona Horizon Banner

Science Matters with Lawrence Krauss

Airdate: October 27, 2015
Arizona State University physicist Lawrence Krauss will explain the latest science news in his monthly appearance on Arizona Horizon.

Guests:
  • Lawrence Krauss - Arizona State University physicist
View Transcript
TED SIMONS: World renowned physicist Lawrence Krauss joins us each month to talk about the latest science news, which this month includes new evidence of when life on earth began. Here now to explain and elucidate is our friend, Lawrence Krauss.

TED SIMONS: Good to see you again.

LAWRENCE KRAUSS: Your friend and mine.

TED SIMONS: Yes. I'm sure you are. Life on -- now, they're thinking it may have begun earlier than --

LAWRENCE KRAUSS: It’s pretty darn early as it was. That is what is amazing. There is a new announcement, one has to frame it properly. I have often said, the first time you mention something it is often wrong. The earth is 4.5 billion years old. Whether you believe that or not it is. And we have rocks that are about as old, in fact, from Australia, rocks that contain Zircon, about 4.4 billion years old in western Australian hills. Rocks that have been around since almost as old as the earth is. And we have seen fossils that apparently are at least as old as 3.8 billion years old. That means life still began pretty darn early. For most of the early period on the earth, it was being bombarded by comets and asteroids -- it was an incredible period of intense bombardment. It looked like the laws of physics would basically say you can't have life. That bombardment period ended 3.8 billion years and then boom life was here on earth, looked like life could develop relatively quickly. A period of late heavy bombardment, between 4.1 billion and 3.8 billion years ago, where we can tell from craters on the moon that it was -- the earth was being slammed as was the moon by lots of stuff. What was discovered by looking at ZIRCON, cubic Zirconium, fake diamonds, you can look at the basically is very old rocks by geochemistry includes material nearby. By looking at over 10,000 bits of ZIRCON from samples in Australia -- in one, they found carbon, and the carbon had all of the signs of being processed by life. It had a much higher ratio of carbon 12 to 13. They like to use carbon 12 instead of carbon 13. The Zircon is dated to be 4.1 billion years. This is crazy, because if it is true, that means there was some things living at a time when you could imagine it was hell on earth literally because any oceans that -- by the way, there’s also evidence that there is water then. When we thought the earth was arid and dry, because of the geochemistry, you can see isotope ratios – and they’re they kind of things that develop in a liquid environment if it is true, it means life at least developed during this period once and maybe it was killed off and then developed again. If that is really true, then, boy, it says that life is ubiquitous in the universe.

TED SIMONS: Talking 400 some odd billion years after the earth was formed now --

LAWRENCE KRAUSS: Within 400 million years -- instead of six to 800 million years. 400 million years, which sounds like a lot of time not compared to the length of this interview, but a long time. Literally that was during the formation period of the solar system. When we just thought that -- planet earth was still evolving and growing. And sometime during that period the moon was greater. A huge Mars-like size object slammed into the earth in that early period knocking out material that later formed our moon. It was not a pleasant time to be around.

TED SIMONS: With this idea a quicker start than we may have anticipated, does that mean when we're looking for life elsewhere or just looking elsewhere, a quicker start means --

LAWRENCE KRAUSS: A quicker start, if it is really there, it means maybe life developed more than once, first of all, on earth. And it means life could be more ubiquitous in the university than imagined. To be cautious, it is important to point out that this is -- the ZIRCON – geochemistry of ZIRCON, absorbs stuff nearby and there could have been a later period when it melted and reabsorbed material. So, it could be that the ZIRCON has been dated. You can compare the uranium to lead isotopes and that tells you how old the Zircon is. Carbon hasn't been dated so I could had that later it melted and reabsorbed the carbon.

TED SIMONS: Johnny come lately kind of thing.

LAWRENCE KRAUSS: Science at the edge. You have to be cautious but it is very interesting.

TED SIMONS: Can you date the carbon? Will carbon be dated or can you get it out of there?

LAWRENCE KRAUSS: I think what really will have to happen is you need a sample of more than one. They have to find more evidence and then you will be able to do statistical samples. With a sample of one, problem of medicine, often a sample of one and it is hard to do accurate science. But it is remarkable and surprising because it has all of the ear marks of life in an object 4.1 billion years old. On the face of it is worth talking about on the program.

TED SIMONS: Something else, the hottest, the biggest double star system ever found?

LAWRENCE KRAUSS: Yeah, you know, stars are often binary systems. In fact, many stars, if not most are binary systems. Our sun isn't. Let me qualify this. This is not a picture. This is an artist's rendering of a double star system in the large Magellanic Cloud, 160,000 light years away. You can see it in the southern hemisphere. A small satellite galaxy on the edge of our milky galaxy. And you can see it. The -- you can see it in the southern hemisphere. They're so big, combined mass 50 times the sun. Orbit each other once a day and basically overlapping. 30% of the mass is kissing like in this picture. Actually two stars merging together. And this is something that is remarkable to see. This represents presumably the last stage of whatever the development of these stars is. Something dramatic is going to happen. And it happens so fast that normally you don't get a chance to see this.

TED SIMONS: How long have they been doing this?

LAWRENCE KRAUSS: Well, they could have been orbiting in extended orbits for hundreds of millions or perhaps -- well, these guys are 50 times the mass of sun. Their lifetime is something like 10 million years. They have probably been doing it millions of years. Last stages can happen in a very short time.

TED SIMONS: Each one 50 times?

LAWRENCE KRAUSS: The combined mass and it turns out if you are 10 times the mass of the sun, you burn your stuff about 1,000 times faster than the sun. Lifetime in the main sequence of the stars, millions of years to tens of millions of years. To see this -- we don't know what is going to happen next. They're overlapping. I mean, it’s amazing to catch this. Huge objects that are much hotter, much bigger than the sun -- the temperature on these things is 10 times higher than the temperature of the sun, and if they merge, then if they merge into a single system, that will be a gigantic star that would probably emit huge amount of material and become what is called a gamma ray burster or something weirder, as they exchange material one or both of the stars may explode and collapse to form black holes. You may have orbiting black holes. If that is the case, then you’ll produce a tremendous amount much gravitational radiation. A new detector came on to look for gravitational radiation to look for this kind of stuff. Either way, we know that system is there and in a short time, not in maybe this year or next year, but we can watch it evolve. To have captured something like this is just amazing, but, you know, it repeats what I said to you earlier. The Universe is big and old. It has a lot of stars. Even rare events happen all of the time. Strangest things you can imagine as long as they're not impossible are happening out there in the universe, and if we keep looking we're lucky enough to capture them.

TED SIMONS: We will be able to keep an eye on this. If it becomes a black hole tomorrow we can watch the process?

LAWRENCE KRAUSS: We might be able to. We have a detector that could detect gravitational waves from the objects that became black holes or a gamma ray burst from the subject. We are looking all of the time for these energetic bursts of radiation that we literally see from the other side of the universe. We’re seeing these weird systems in formation. It is amazing to think of. Can you imagine something 25 times the mass of the sun, huge, orbiting another star once a day. We orbit the sun once a year. Two stars close together, every day twirling around.

TED SIMONS: That's amazing.

LAWRENCE KRAUSS: It is.

TED SIMONS: Before we go, another photo here. This one of a much smaller --

LAWRENCE KRAUSS: Much smaller object. Today is the day of neat photos.

TED SIMONS: This is a photo of Saturn's moon's north pole?

LAWRENCE KRAUSS: Enceladus, which is a moon of Saturn we used to think was like a cue ball. We discovered as the Cassini satellite which was looking at Saturn, as it got close to Enceladus we discovered it is not as cracked. This is from 1800 kilometers. What is neat, the reason I wanted to show the picture, tomorrow, tomorrow the Cassini satellite is going to dive down to 50 kilometers from that surface and what is neat about this is it has water geysers. We have discovered basically hot water shooting out from inside the planet. We think that the oceans are maybe 48 kilometers deep and the hot water is coming from down below just like hot vents on earth where we think the first kinds of earth, life on earth formed. The whole thing is coming together.

TED SIMONS: It is.

LAWRENCE KRAUSS: Tomorrow, the satellite will fly through one of the plumes and may be able to see if there might be evidence of life or at least the raw materials of life and then we will want to go there with a robot later on.

TED SIMONS: Back to the photo, this photo before we get all of the great stuff later, what exactly are we looking at?

LAWRENCE KRAUSS: We're looking at ice -- it is ice planet with lots of cracks and lots of dimples and lots of craters. What's happening, it is an active system. We used to thing those moons would just be frozen solid. But probably because of the incredible gravitational pull of Saturn, there is tidal forces that -- there is -- the gravities much higher on one side of the moon than the other. And that causes stretching and cracking and heat to be generated and that might be the source of the heat inside of -- it is clearly a dynamical system. You can see water geysers literally spurting out of Enceladus, a total surprise at the time.

TED SIMONS: Is there any terrain there? Do you think it is all just --

LAWRENCE KRAUSS: Ice over a 50 kilometer thick ocean.

TED SIMONS: So it is all ice over ocean.

LAWRENCE KRAUSS: Ocean. The whole thing is only 500 kilometers across. Amount of water in the ocean is probably like the amount in lake superior, about the same amount of water.

TED SIMONS: Like the fraction of the size of our own moon?

LAWRENCE KRAUSS: Small fraction size of our moon. It still has got a liquid ocean and hot water and as far as we can tell, that was -- on earth, those were the ingredients of life. And we have every bit of evidence that stuff that is coming out of the geysers originated from the ocean floor. It was hot water that spurted up and basically shot through the ice crust. So, when we go through those -- the water plumes, we will be looking at water that comes deep in the interior and look for organic materials. I don't know if the satellite can see that exactly but will look for conditions that will tell us maybe it is the best place to look for life elsewhere in the solar system.

TED SIMONS: I think something is happening down there. I think they will find something down there. Do you want to quote me on that?

LAWRENCE KRAUSS: Do you want to bet? I'm the same with you. I think it is one of the best places to look for life. Something is happening.

TED SIMONS: Something going on down there.

LAWRENCE KRAUSS: It’s exciting and that means there’s more for you and me to talk about.

TED SIMONS: Tomorrow they’re going to go flying around in geysers.

LAWRENCE KRAUSS: Probably be a little soon to find out what they did.

TED SIMONS: Last question --

LAWRENCE KRAUSS: Think about tomorrow.

TED SIMONS: I always think about tomorrow.

LAWRENCE KRAUSS: Our satellite, 48 kilometers from the surface of that moon.

TED SIMONS: I never stop thinking about tomorrow.

LAWRENCE KRAUSS: Especially and you don't think I stop thinking about what I want to talk about.

TED SIMONS: The last thing about the -- what was this Cassini thing supposed to do? The mission --

LAWRENCE KRAUSS: The mission to boldly go where no -- the mission to explore Saturn and its environment. It is an amazing satellite. And it has produced in my mind one of the most amazing images that I have seen. Eclipse of the sun as seen from behind Saturn and if you look between the rings of Saturn, you see a little blue dot. Guess what that little blue dot -- amazing picture. Go on the NASA web site and look at some of those things. They are just amazing. We are only get there -- we send satellites and robots and that is the best way to explore the solar system.

TED SIMONS: Again, the idea of sending humans doesn't make a heck of a lot of sense.

LAWRENCE KRAUSS: Not to environments like that. Not right now.

TED SIMONS: Interesting. Great photos.

LAWRENCE KRAUSS: Great photo day. Visual aids always help when you are dealing with slow students.

TED SIMONS: Well, and it is a pleasure to see you as well. Thanks, Lawrence. Good to see you. We will see you again next month. Wednesday on "Arizona Horizon," we'll take a closer look at an education funding plan being considered by state lawmakers. And we'll take you to the Shemer art center in Phoenix. That's at 5:30 and 10:00 on the next "Arizona Horizon." That is it for now. I'm Ted Simons. Thank you so much for joining us. You have a great evening.

VIDEO: "Arizona Horizon" is made possible by contributions from the friends of eight. Members of your Arizona PBS station. Thank you. When you want to be more informed,