Krauss on Science

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Arizona State University physics professor Lawrence Krauss makes his monthly appearance on Arizona Horizon to explain the latest science news.

Ted Simons: Good evening and welcome to Arizona Horizon, I'm Ted Simons. Every month asu physicist and best-selling science writer Lawrence Krauss joins us to discuss the latest in science news, which tonight includes details of a recent spacecraft landing on a comet. Here now is our good friend, Lawrence Krauss. How are you?

Lawrence Krauss: It's great to be back here on the holiday season.

Ted Simons: It's good to have you back. Hey, have you seen this movie, interstellar about all this great science stuff?

Lawrence Krauss: Let's not waste valuable time talking about nonsense. It was one of the worst movies ever made.

Ted Simons: Oh, how come?

Lawrence Krauss: There was nothing good about it. The science was miserable. The plot was stupid. And it was derivative. Other than that, though, if you have good popcorn and maybe felt like a rest, it's a good place. It's too long. As I Tweeted three hours could seem like 23 years, oops, gave it away.

Ted Simons: But these people going through a worm hole to come back and save the Earth and all --

Lawrence Krauss: Save the Earth from what, and how did they save the earth? And with a formula? And how was your thawing with some ridiculous mold eating somehow up the oxygen in one generation it took 2 billion years to produce? It was just plain silly.

Ted Simons: Last point, Kip thorn, another renowned physicist-

Lawrence Krauss: A friend of mine, and a very good physicist, and I feel badly that his name is associated with the movie. He had an idea about how to do a movie about worm holes, you know, and real stuff, and then it got turned by Hollywood into garbage. It's the process where they churn things and produce garbage in the end.

Ted Simons: At least you are not wishy washy about that. Let's talk about that --

Lawrence Krauss: The "New York Times" asked me to see it, and I told them that they owed me three hours of my life. They wanted me to comment on it. Anyway. Sorry, go on let's talk about good stuff.

Ted Simons: They asked you to see a film on their dime?

Lawrence Krauss: Yeah, but they never paid me for it.

Ted Simons: Let's get to the reality here, the rosetta mission, ok, spacecraft, finds a comet, lands a little lander. Why this particular comet?

Lawrence Krauss: Because it was accessible, I think, but I wanted to -- we're going to talk about a lot of neat stuff, and I want to start with the heavens before we move to the Earth being Christmas season and all. We're going to go to stars and talk about the real wisdom we get from stars, and the rosetta mission is amazing, and I am sure that everyone has heard of it. It has gotten a lot of press. It was not just finding the comet, we knew it was there, but we had to plan a mission to get to it, to get up to speeds, so I think it's what, 40,000 miles per hour, and the spacecraft, in order to get there, took ten years because its own fuel would not have done it. It would have to be sling shotted around planets to get there and then try and land a little lander on this thing, where, in fact, the lander was just -- was let to fall because it did not have -- it could not be directed, and what happened, it used the gravity of this small comet, which is what, 2.5 miles across, to gently pull it down. The problem -- which is an amazing engineering problem, the fact that it got so close to working is amazing. The lander fell down, at the speed at which you would walk because that's how gentle the gravity is, and it was supposed to have rockets that would hold it to the comet and some harpoons, and unfortunately, those didn't work, so the comet bounced, and when you bounce, and there is no gravity, it bounced about a half a mile up in the air, came down, and bounced again, and unfortunately, landed in a place with some shadows because right up against a cliff, basically, on this comet. But, the reason we want to land on a comet -- so therefore, it wasn't going to get as much sunlight as it would otherwise, which powered the solar cells, so it worked for 60 hours, and it's not clear if there will be enough light for it to function after that.

Ted Simons: It's in hibernation?

Lawrence Krauss: Yes, in hibernation, which means it's not dead but hibernating, and it was big on this spacecraft, in order -- this is a ten-year mission, in order for the spacecraft to, actually, function, when it needed to, it went into hibernation for 2.5 years on its trip to the comet, and only last January was taken out of hibernation, and that was a really nerve -- knuckle biting moment because you did not know if it would come out of hibernation, and it did. Most aspects of this mission was successful. The fact that you could steer and parallel the comet traveling 40,000 miles an hour and then land -- let a lander go is just amazing, and of course, it could have worked better if it had worked all the way, but we learned an incredible amount. The reason that we want to land on a comet is that these -- the comets are primordial material. 4.5 billion-year-old stuff, balls of ice, and dust, and they, among other things, brought material to the Earth, so, this is the material, some of which may be seeds for life so we wanted to find out what's on the comet and already, they found out it was harder. They thought it would be a softer surface, but some other interesting things were -- two things. One of which we talked about, the spacecraft, itself, which is paralleling the comet, has looked at gas as being emitted by the comet, looking at water, and as you may remember from an earlier discussion, we wonder where most of the water on Earth came from, and there is a big debate whether it came from rocks or from comets, and the problem is, most comets have a different ratio of the two isotopes of hydrogen, in our oceans, there is a bit of it, which is why we can make heavy water, it's a heavy version of hydrogen in one part in 100,000 or so, when we look at comets, many have a different abundance. So, if they have a different abundance of heavy to light water, how could they have transported the water to Earth? One recent comet we found, actually, had the same abundance as Earth, so one of the things that we want to know by going on this, is does this have the same abundance, and in fact, it is different. So again, it tilts the scales in favor of the idea that maybe the water, it was primordial was buried in the rocks on Earth and couldn't evaporate or maybe it was brought by asteroids, rocky things, instead of ice. Another thing that we learned is that there are organic materials. The lander landed long enough to be able to sniff out carbon and hydrogen suggesting organic compounds, one of the questions that we have is was life on Earth seated by comets? But, were the elements, the molecules that make up you and I, the basic organic constituents that later became life, did they come from comets? And indeed, we know that at least it's possible that the organic materials are on the comet. So we learned an incredible amount, as an engineering feat, it's amazing, and I just think that it's, it captures wonderfully our abilities, and you know, there is another story at the same time, while comets are in the news, another neat thing that we learned about comets, they are not just in our solar system. Recently, observations of a star, I think, beta, 60 light years away, has been able to discern the presence of two large comet systems around the star. One, which is being tugged by a massive star, a massive planet, and the other, it looks like it was created recently, by, by the collision of two planet-like objects. What's interesting is, we have two populations of comets and asteroids in our solar system, one of which is largely affected by a massive planet, Jupiter, and one of which we may have come from the collision of two proto planets that would have been planets if they had not collided, so we are seeing something similar in another solar system. And that's rather fascinating. The fact that we can see clouds of comets around other stars. So, we're learning about our solar system, and potentially, our origins, and how typical we are or not of all the solar systems in the galaxy.

Ted Simons: With that, now, and with this landers on the comet and everyone is watching and seeing what happens, the comet is going to be nearing the sun, is it not? What changes?

Lawrence Krauss: Well, the comet, as it nears the sun begins to expel gas, and it would be great if -- and when it gets near the sun, the lander will have more sunlight and be able to operate. Eventually, of course, we'll get close enough to the sun that the environment to the comet will be very volatile as it shoots things off, and the lander will stop operating, but the spacecraft is paralleling along the side, so we'll be able to see the processes, that produce the comet's tail. We'll get a close-up view of those processes that happen as comets go around the sun and how they expel material, some of which later on remains in the solar system. Some comets get absorbed in the sun, but like Hayley's comet, a lot of them have huge elliptical orbits that take them back every few hundred years, so, this process gets repeated thousands of times before the comet disappears, depositing material in the solar system.

Ted Simons: And quickly, the European space agency seems like it was taking the lead. Why them and not us? Where was NASA in all of this?

Lawrence Krauss: Well, it had other priorities. I think you have heard me say, and I am not popular with some people to say that, we spend too much time trying to send humans into space, instead of doing the interesting stuff, like sending landers to see comets. NASA has had several proposals, and we do have a planned rendezvous with a comet, but this was one of the space agencies' missions, it started more than a decade ago. It was launched a decade ago. The planning for it probably began two decades ago. It's amazing that this thing took ten years to get where it did, so, and that means, by the way, that the technology on these spacecrafts are 20 years old. That -- just think of that, and you already know when -- think about the technology on say "Apollo." As you know the computers, they were far less powerful than the ones on my phone.

Ted Simons: Yeah.

Lawrence Krauss: And yet, we managed to send people to the moon. It's amazing.

Ted Simons: Think about any computer 20 years ago, compared to what you can get here.

Lawrence Krauss: Right. And Apollo was 50 years ago, so that's amazing.

Ted Simons: All right. Let's keep it moving. The oldest living star in the universe has -- how do we know this is the oldest living star?

Lawrence Krauss: It has a really long beard.

Ted Simons: This is a supernova, not exactly what we're talking about.

Lawrence Krauss: But, supernova are very important because they are exploding stars, and they produce the materials that produce you and me as I have told you before. Every atom inside you and me has been inside the exploding star, because in the -- at the beginning of the universe and the earliest moments of the big bang, the only elements that were created in those times when the universe was a billion degrees were hydrogen, helium and lithium, but all the important stuff, the carbon, nitrogen, oxygen, iron, all that stuff is created only in the nuclear furnaces inside of the stars, which then are kind enough to explode and expel those ingredients, which then go into another generation of stars, which get cooked again and again and again, and the material in you and I has gone through 10 or 20 exploding stars, the most recent one probably 5 billion years ago which triggered the formation of the solar system. Now, the oldest stars are, since we're building up heavy elements, as material gets processed through stars, and they are essential for our existence, we could not have existed early in the history of the universe because there was not iron and oxygen and nitrogen and all the things that we need and carbon. So, what we can look at is stars and the spectrum, the fingerprint of the light emitted by the stars, and it gives us the elements that are inside the star. What was discovered by accident, and I am happy to say, as you probably know, I spent time in Australia and at the observatory, and they have a star mapper, which is looking at a million galaxies and in the southern hemisphere. It also looks at stars, and it looked at the star, and it was weird because when it looked at the spectrum, there was no iron. There was less than one part in a million of iron compared to the amount in our sun. If you work that out, that means that the star must have formed right after the earliest generation of stars formed. It is maybe 200 million years after the big bang. 13.6 billion years ago because it does not have any of the heavy elements that were later built up, and the big question is, how did they go there?

Ted Simons: And I was going to ask that.

Lawrence Krauss: Good.

Ted Simons: In my research, I discovered that the Milky Way is 13.2 billion years old, so how did this thing, how did, how come this is older --

Lawrence Krauss: The point is, the Milky Way didn't form all at once. It formed up by cannibalism, and what happens, is we think, is the galaxies, the large galaxies don't form all at once. What happens is the small conglomerations of gas form, and they, then, collide and build up and build up, and the big, as it gets bigger, like Jupiter was eating comets, the galaxies eat the small globs of gas and build up and build up, and so our Milky Way took time to build up because first, the small things had to collapse. What is thought about this old star, who probably is formed and lived in a small gas cloud that existed before our Milky Way formed, and be it was captured into our Milky Way, which is why --

Ted Simons: Ok, all right, that's how you get that.

Lawrence Krauss: That's how you get that. Forming before the Milky Way and gets eaten and just like the food you ate today was formed earlier.

Ted Simons: A lot earlier.

Lawrence Krauss: Unless you eat it live.

Ted Simons: And ok, and all right, now, something else that I just -- again, I find this fascinating.

Lawrence Krauss: I love your research.

Ted Simons: There idea -- I do a lot of research.

Lawrence Krauss: I can see.

Ted Simons: And new coating material that radiates heat, okay, we understand radiates heat back to the atmosphere, and no, no. Radiates heat beyond the atmosphere, into space. How does this happen?

Lawrence Krauss: It's even better than that. It's even better than that. I love the story because we're going to preview, spoiler alert, we're going to talk about climate change, but this is anti-climate change because climate change happens, and it's happening because sunlight comes and makes it through the atmosphere, and converts to heat, which gets trapped in the atmosphere. The infrared radiation. These people have developed the material, which does precisely the opposite. It reflects sunlight, so sunlight can't penetrate it, just reflex it. It's a perfect mirror, but what it does is takes the infrared radiation, the heat, and turns it into a frequency, which does not get absorbed in our atmosphere, and therefore, gets emitted out into space. And space is cool enough, and it does not know our atmosphere is there. There are frequencies that don't get absorbed by radiational atmosphere. All the heat light, the infrared light emitted by this material does not get absorbed in the atmosphere, does not heat up the Earth, therefore, and because it does not get absorbed in the atmosphere, it gets dumped into the vacuum of space, so it transports heat from a, in this case, an office building, directly out of the atmosphere. It would be fine if it transported it out of the building. It could cool the building, but it would be bad for global warming. This is a material without any -- it's, basically, a refrigerator that works without any power. It reflects sunlight, so the sunlight doesn't heat up the building and takes any heat produced by the occupants and the lighting inside the building, and transports it directly into space because it emits it at a frequency of light that does not get absorbed in the atmosphere, so if you wish, it's anti-global warming, it's a manmade material, does the opposite of what our atmosphere does.

Ted Simons: And the key is transforming that heat into this infrared thing that can go straight through like an alleyway?

Lawrence Krauss: All heat, of course, gets emitted by, you know, when you stand near your oven you feel the heat. That's infrared light that's coming from the oven. But, most of the frequencies of infrared emitted get absorbed by your body or the atmosphere. What they were smart enough to do was get a material that, basically, would absorb the infrared radiation from inside the building, the heat, and turn it into a different frequency of infrared radiation that happens to be a frequency that can escape.

Ted Simons: Ok. Let's get into global warming in a second. But the transformation process doesn't that require energy? Doesn't that emit heat, if you will?

Lawrence Krauss: No, because the materials do these things naturally. You emit the clothes on your body take sunlight, absorb some of it, reemit it, and sometimes produce different colors. It's just a property of materials when they absorb light, they don't always reemit light in the same frequency they absorb it. So, it's amazing. It's a wonderful -- in this case, it's an intelligent design, but it really works.

Ted Simons: Ok, we have got -- you threw that in there. I caught that, so we have got this now, regarding a positive aspect of global warming and climate change, and this as India decides it is going to go full bore into coal.

Lawrence Krauss: Yeah, the news on climate change has been miserable in the last year, and the last -- there have been two, two things in the last month or two that, well, a bunch that are negative, and none of the news, except the United States just made a treaty with China, which in principle is nice.

Ted Simons: Indeed.

Lawrence Krauss: Except what happened is India, which is burning 500 million tons of coal, has now said that their goal for 2019 is to go up to a billion tons. Now, not only is that miserable, in fact, not only is that almost enough on its own to push us past the tipping point, which we're arbitrarily close to, which will ensure the Earth heats up to a level that is, in many ways, disastrous, but also awful for the environment. It is strip mining, the worst polluting kind of coal mining, and really, it's unfortunate that, I mean, coal -- you will get letters for this, but coal shouldn't be -- we should just forget coal. Coal is the worst kind of energy Production -- it does not even employ many people. But, in India, it's the worst coal production, and the fact that they are increasing over five years, 500 million tons a year of coal burning, is disastrous at a time when, at the same time, we're getting news that we're experiencing extreme weather. Some people will say, look, it's the coldest, you know, winter, you know, November on record, and where's global warming? It's the extremes that happen when you eject -- when you eject more energy in the atmosphere because of global warming, you change things like the polar vortex and currents in the ocean, and we're seeing winter weather that's never been seen before. People have to dig tunnels to get out of their houses in the east coast, and these extremes of weather are another example of the injection of more energy in the atmosphere, and along with that, there was a recent report by the World Bank called turning up, I think turning up the heat or something. You know, when you see, what you see from the international panel on climate change, there are, their reports are conservative because they have to get consensus so they take the lowest common denominator, but climate scientists say the actual global warming is now much more likely in this century to be seven degrees, not just two degrees, seven degrees on average, just be extreme, and in fact, there is good evidence that the west Antarctic ice sheet is already going to melt, and I mean, it will slide into the ocean, and there is nothing that we can do, and even if we stop burning all fossil fuels, and if that happens, and it looks like it's inevitable, sea level rise will be four feet, so goodbye south beach Florida, and in fact, for India, which is helping contribute to global warming, it's estimated that at least 37 million people will lose their habitat right now because of rising sea level, so it's an unfortunate situation. We're going to have to learn, in some sense, we cannot stop it at the level that now exists. We hopefully will stop it at a more extreme level, which is what we need to do, but what already is happening is going to produce dramatic changes, and we'll, in some places in the world, there will be no way of getting around it. We will just lose specific islands, but even in advanced places like the United States, there is going to be severe flooding and extreme weather that we have to get used to, and the point is, you know, we broke it. We have got to fix it, and we have got to think -- we cannot just bemoan the future, we need to think of ways to capture Carbon Dioxide.

Ted Simons: We need to stop it right there. At least we got the one positive thing with the reflective mirror.

Lawrence Krauss: Let's end on a positive note, it shows that human beings, at least with technology, can try to address problems. Once we realize the problems are there, and fund them, so, we have got to use our brains.

Ted Simons: I think that we used our brains this show.

Lawrence Krauss: I hope so.

Ted Simons:Good to have you here.

Lawrence Krauss: Good to be here.

Lawrence Krauss:Physicist, Arizona State University;

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