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Science Matters with Lawrence Krauss

Airdate: March 24, 2015
Arizona State University physicist Lawrence Krauss will break down the latest science news in his monthly appearance on Arizona Horizon. Among his topics, a dramatic quadruple image of a supernova.

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

Keywords: science, lawrence krauss, asu, news, image, supernova,

View Transcript
Ted Simons: Best selling science writer and physicist Lawrence Krauss joins us each month to break down the latest science news including intriguing information regarding one of the moons of Saturn. Here now is ASU physicist Lawrence Krauss.

Lawrence Krauss: Nice to talk to you. Sounds like a climatologist.

Ted Simons: We are going to get to that.

Lawrence Krauss: OK.

Ted Simons: Let's talk about Enceladus, Saturn's sixth largest moon, but there's more.

Lawrence Krauss: There's more. It looks like a snowball. And we used to, in the old days thought it was just a rocky snowball. And it's really kind of interesting because but in fact what was discovered a while ago, probably by Cassini which is a satellite we sent to go around Saturn there are geysers coming out of it. There are geysers of water going shot out. The really interesting thing is that it's been realized that one of the outer rings of Saturn, you can see the geysers in that picture, one of the outer rings is actually mostly populated by material that's been shot out of Enceladus. They can learn about it from the outer ring of Saturn. It turns out the kind of dust that occurs depends on the temperature and solidity of the water that's carrying the dust. And so water of different temperatures will allow, the water will evaporate but the dust grains will be left over. Depends on the salinity and the temperature of the water that goes into it the dust grains will be larger or smaller. By looking at the dust grains in the rings of Mars, they have been able to probe the inside of the moon which is amazing and have found that, in fact, there's hydrothermal activity like there is in the earth. These geysers, it's hot water underneath that ice about 200 degrees in temperature from the size of the silica dust particles and the rings of Saturn. And the salinity and acidity, 4%, lower than our ocean, the pH level is not that different than our ocean and this is really interesting because it's very similar to the nature of the hydrothermal vents in our oceans in which we think the earliest forms of life formed.

Ted Simons: There could be little bacteria running around?

Lawrence Krauss: Who knows what there is running around. What's kind of interesting is that, this means that the conditions that are similar to the early formation of life exist underneath these deep oceans underneath this frozen surface. What's neat, you may say, why is it hot? You may ask me that.

Ted Simons: Why is it hot?

Lawrence Krauss: What a good question. The answer is it's not like the earth which has radioactivity and a molten core. It's being close to Jupiter. Its gravity and the tidal force that is stretched and it compress it as it goes around Jupiter literally just like if you pull a rubber band back and forth, it heats up the rubber band. That's what heats up the insides of Enceladus.

Ted Simons: But that’s different than the Earth, isn’t it?

Lawrence Krauss: We can't say whether the time frame, life evolves on earth over billions of years. And although actually relatively quickly within a few hundred million years, but how long has that hydrothermal activity been happening in its orbit around Jupiter? We can't say for certain. It's happening now and what's really kind of neat it's been pointed out, look, it has wonderful satellite as it is, like many satellites is based on 20 to 30-year-old technology. If we sent a new satellite out, looking for signs of organic materials, potentially life in these geysers we would be able to without going into it, we might be able to probe for biological activity, frozen dead microbes in those geysers.

Ted Simons: I think it's amazing you are basically talking about warm oceans underneath -- this is water on a moon.

Lawrence Krauss: So far away from the sun that it's just a spec away. It's really amazing. It's gravity heating up a moon. And Enceladus is not the only moon that is frozen on the surface that probably has oceans underneath it.

Ted Simons: Yeah.

Lawrence Krauss: Europa from Jupiter is another one. But it appears, we can actually, what's really neat by looking at the rings of Saturn we can learn what's inside. I find that amazing.

Ted Simons: No kidding. All right. Let's get back to Earth here and global warming. There's a report the rate could double in the next -- it's getting increasing? Exponentially?

Lawrence Krauss: This is a study in science. And there's another study we will probably talk about next month which is more interesting in a way. What it tries to do is look at periods that are short enough to kind of compare with sort of the changes that have taken place. 40-year periods, instead of long-term periods, and look at two things. The measured changes over the entire earth and also over different regions, over 40-year periods over the last 2,000 years compared with climate models. What you are sort of looking at is, here in this figure, the upper part of it is showing the rate of change of degrees centigrade per decade so an early period between 1851 and 1930 as measured basically, and the measured basically changed between 1971 and 20 and you can see the solid lines are the later period of industrial production, and the dotted lines are the early period. And the fact that all of the solid lines are higher means that basically the rate of temperature change has doubled over that period. Now, the bottom curve shows that change, you see updates in 1980, there wasn't much change. And then it began to increase and all of these different curves represent different models and different, well, represent, sorry, a set of models over different regions because one of the things of a climate change that people don't seem to understand it doesn't mean that change is the same everywhere. Some places on earth get colder. Look at the weather in New England right now. Some places get warmer and the amount by which they change is different. We can measure and it we can compare it with models. But all of these, what's kind of concerning is, all of these represent models that predict all the way through the end of this century. But they assume these models all assume that basically we are Senator and we begin to respond to climate change which is not clear given the politics of the world right now. And even then, if you look even in the best of all possible circumstances, where we respond today, the rate of temperature change continues to remain high throughout the whole century. There's another figure in that paper which is much worse assuming we don't do anything, and then it just shoots right up from a .2 degrees to .4 degrees every decade.

Ted Simons: This is because of greenhouse gas buildup in -- could something else be affecting this?

Lawrence Krauss: Well, you know, they look and say there's aerosol, there's lots of physical things that you put in there. Aerosol formation and all sorts of other things than factored in and what they find out is the season activity to other things is not as severe starting from 1980 onward as greenhouse gas productions. Certain parts of the model, the uncertainties in the model are really the response of the earth to greenhouse gas production. But these other factors become less significant. They are much less important in the variability over the last 1,000 years. You can't see in the curve but they compare the model predictions because these are models. People who deny climate change say it's just models. They compare them over each region, Antarctica, Europe, the America, the past 2,000 years with the model and you can see the models fit the data pretty darned well.

Ted Simons: So why the Arctic, Europe, U.S., larger increases than the global average? Why?

Lawrence Krauss: Well, there are lots of factors. There's the prevailing winds. Obviously, North America, you talk about El Niño, and Europe there's the influence of the oceans which are huge. In fact, I think next time we may talk about the fact there's other damning evidence that suggests that because of melt next Arctic, the currents that, the temperature in the ocean which drives currents which drastically affects the temperature in Europe is changing and Europe lie to get colder because of these changes in currents. There's many different factors and they are putting the models as best as we can. You compare the models with the data to see how got models are.

Ted Simons: All right.

Lawrence Krauss: It means, it really means that we are in a century of anthropogenic global change and it seems to be the major factor determining what's going to happen we don't know how fast the earth will respond or how dramatically it will respond but the data suggest that even if we do something sensible, we have to begin to consider serious temperature increases and that means adaptation both for species and technology for you and I and people in Florida might want to consider moving.

Ted Simons: All right. Let's get back to space where things are.

Lawrence Krauss: Safer.

Ted Simons: Yeah.

Lawrence Krauss: Far less mail.

Ted Simons: Multiple images of an exploding star. And this is because of what magnification?

Lawrence Krauss: Because of space. The curvature of space. It's amazing. We have a bunch of images here that you want to see. This is, so this is a galaxy and what Einstein told us is light bends.

Ted Simons: Right.

Lawrence Krauss: Due to mass. And what can happen is, let me come back to me because I want to wave my hands in a way.

Ted Simons: OK.

Lawrence Krauss: If you have a galaxy and a light source behind it, we have talked about this before a little bit. The light rays will go out and then due to gravity they will be bent and come back. And you can form multiple images of an object behind a galaxy due to this process of the lensing by the curvature of space. Now what's really been amazing maybe we can go back to that other image, in this galaxy, the host galaxy here actually is about, oh, probably seven to 8 billion light years away. Maybe a little less. It's been lensed by intervening, an intervening galaxy and an intervening cluster of galaxies and you can see at the bottom these four dots. They are four dots that appeared in November that weren't there before that. Now, that -- the only way that can happen is if a star explodes. Those four dots are all different images of a star exploding. The interesting thing is, because there's -- this is a test of the nature of space and time. So because of the fact that each of those images involves a light trajectory that's slightly different, the time it would take for each of those images to get to us will be different because it will be traveling over different distances. Like if you go from Phoenix to Los Angeles by driving down south through San Diego or going up north, it would be different. In this case, the models predict variations of anywhere from a week to a month before the different images could appear and they began to appear at different times. It's an amazing demonstration of the fact that space can curve things. It's even more exciting if we can go to the next image -- it seems to me because -- if we can to go that next image which I hope will come up -- this looks really complicated. But there are three points, 1.1, 1.2 and 1.3. It turnings out the galaxy in which those super Novas are seen is itself multiply imaged by a bigger intervening cluster of galaxies and all of those three images -- 1.1, 1.2, 1.3 -- are different images of the galaxy itself. Because clusters produce a much bigger splitting, the different travel lengths are very large. And, in fact, the four images were observed in this image 1 boy 1 as a super Nova but we predict the 1.3, anywhere between a year and 10 years from now those images will appear because it takes longer. And when we measure that, we will actually be able to test for how much math is in that intervening cluster and how far away it is. We can actually be able to measure the properties of space and time. So we make a prediction that, boom, sometime in the next decade, four dots are going to appear in that third image. I find that amazing.

Ted Simons: Are you talking basically plotting? Is that what you are doing with these four spots? Plotting and learning about distance?

We are plotting because -- by measuring the time it takes --

Right.

Lawrence Krauss: -- for those images to appear, we see how far they are separated in space because we can see that in the cluster. And therefore, we can say, well, we know trajectory goes this way and another way but if we can measure the time difference it tells us how far the trajectory is traveling and tells us the distance accurately to that cluster. And then we can measure, if we can measure cosmic distances more accurately we can measure the expansion. Universe more accurately so we can use the appearance to measure not only properties of big distances but also the properties of that cluster. It's kind of a dream system. It was first imagined actually in 1964, I believe, that one day we might be able to see an exploding star and see the lens and use that test the properties of space.

Ted Simons: Wow.

Lawrence Krauss: Indeed it's happened.

Ted Simons: This is Hubble?

Lawrence Krauss: It's the only way you can have the resolution to see that kinds of stuff. Basically, the Hubble space telescope, going back, looks at that system over the next decade for the time that suddenly those four exploding stars which happened billions of years ago, the stars exploded billions of years ago, we are just seeing them now. In one place we will see them in a decade from now. It's kind of neat see the properties of space we have that way.

Ted Simons: Is it OK if I don't understand a single thing you said.

Lawrence Krauss: As long as you say wow and smile it looks good.

Ted Simons: Thanks for joining us. Good to see you.

Ted Simons: Wednesday on "Arizona Horizon" we will have the latest from the state Capitol as the Legislature hurtles toward sine die and we will meet a local winner of a national science talent search. That's at 5:30 and 10:00 right here on the next "Arizona Horizon." That's it for now. I'm Ted Simons. Thanks so much for joining us. You have a great evening.

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