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Science Matters with Lawrence Krauss

Airdate: June 17, 2015
Arizona State University Professor Lawrence Krauss brings us up to date on the latest science news in his monthly appearance on Arizona Horizon.

Guests:
  • Lawrence Krauss - Arizona State University Professor
Category: Science

View Transcript
TED SIMONS: Each month we welcome ASU physicist Lawrence Krauss for a conversation on the latest in science news. Here now is the ever-popular Lawrence Krauss. [Laughter]

LAWRENCE KRAUS: Every introduction gets better.

TED SIMONS: Good to have you here.

We're going to start with something we kind of talked about in the past. It was the lander on the comet, but it was sleeping, hibernating.

LAWRENCE KRAUS: It bounced and went to the wrong place and didn't get enough sunlight. That was November 14th, the last time it went to sleep, because it didn't have any power.

T5ED SIMONS: New news from the comet.

LAWRENCE KRAUS: And it came from a tweet on the comet, the comet tweeted to the lander saying I'm awake, how long have I been asleep? As the comet, as they do, it's approaching the sun. What's happening is the environment has gotten more favorable. The temperature in fact at the learned is something that you and I could live with, not happily but about 23 degrees Fahrenheit. Something we could live with. Under those conditions it's not getting a little over two hours of sunlight a day. Now that it's closer to the sun, conditions are such that it's really amazing. It doesn't seem to have degraded at all. During the sleep systems seemed to be working. It's now communicated twice and people working on it are theorizing they will not just get some data, which they have gotten, but they will get the lander to perform experiments, which is really trying to test the surface and smell the atmosphere. The great thing about comets, they are primordial, they are balls of ice from the beginning of the solar system. You're testing stuff, seeing it –

TED SIMONS: Lets talk about the comet itself. Where is this comet? How big is this comet?

LAWRENCE KRAUS: Oh, good question. How many miles from the sun, I don't know. Its size is relatively small, something on the order of 10 kilometers across, something like that. You're looking at pictures of it. It looks like a big object. But basically it's an object that's small enough so that the gravity of the comet was so small, when the lander landed, it actually bounced. And an object that's tens of kilometers across has very, very small amounts of gravity. I don't know the exact distance from the sun. But what's really kind of neat about this is the comet is going to get its closest approach to the sun in August. In some ways this is a stroke of good luck. If the comet had landed on the sunny side, if it had landed in a place that's sunny, where you can see it instead of in the shadow, then by now the environment would be hostile. It would have given information in the early stages of its trajectory near the sun. But now it'll probably be alive at the point of closest approach and will give data that hadn't been given at all. If it stays sunny.

TED SIMONS: Some basic qualifications here how often does it orbit the sun?

LAWRENCE KRAUS: You're asking me questions I wish I knew the answers to. Well, actually -- comets can be per termed and some of them will hit the sun. The comets come from the outer edges of the solar system as they come in. It comes once every 80 or 90 years, once in a lifetime. They go to the outer reachs and come back. Ultimately most comets that get close to the sun don't last that long.

TED SIMONS: Why?

LAWRENCE KRAUS: First of all, they melt. This comet is shooting off jets that hadn't been expected, we're learning a lot. The orbiter is nearby, about 180 kilometers away. It's now getting closer so it can talk to the lander but it can't get too close because it's shooting off all this gas towards the sun. Eventually it'll be crashed into common. It'll survive but comets can only do that for so long, they lose material and eventually melt like a snowman.

TED SIMSON: I think we have closer shots when it was very, very close earlier.

LAWRENCE KRAUS: This is amazing. And what I love about this, and we may get to it, you'd never get these meteorologies? These environments are so hostile and it took years and years for the satellite to catch up to the comet.

TED SIMSON: What’s being communicated?

LAWRENCE KRAUS: Now, we've got the lander down there communicating with the Rosetta, the orbiter that took these last November. It's information on the status of the actual lander. And all the signs are good. What is going to be done next is give it some instructions after you do some scientific experiments. There's more information it got that's sort of stuck there. It's like a crappy cell phone connection. There's U. of A. seconds. The first time around earlier this week, 85 seconds. As you know if you've ever try to download, if you get a crappy connection you have to start all over again. Conditions look good and they think it's going to be better and better and better. The last -- I heard scientists are involved so they can give manned experiments.

TED SIMONS: And what experiment are you most interested in?

LAWRENCE KRAUS: You know, I think you want to know what the makeup of the comet is, and you can tell that by sniffing its environment. Ideally it would have been nice to drill down, but the position is so precarious, they are not likely to do that. It's basically on the -- by smelling the environment you can tell the composition of the comet, what's the primary composition of even the water. I think before the ratio of heavy water to regular water is different than on the Earth. Enough comets have produced all the water on earth. But if the Hydrogen is different, maybe the water came from somewhere else.

TED SIMONS: And we have talked about that. Something else we've talked about is the idea of manned space flight as opposed to robotic space flight, in a rover. You aren’t crazy about the idea are you?

LAWRENCE KRAUS: For research it's fine, you could never do that kind of aircraft for humans. When you send humans into space, 99.9% of the money is spent on trying to keep them alive and getting them back. The only official way to do it in any way. Most of the money, fuel, energy, comes into getting them back. That I don't I don't feel has been adopted by lots of groups. It sounds like a death sentence. So you go there and you don't die right away. Unfortunately her enthusiasm adds to the hype. The difficulty of sending humans into space is so incredible and expensive this would cost tens or hundreds of billions, if you can solve the technical problems. I was just reading one MIT group is looking at it. Even if they could survive the voyage without enough radiation to kill them by cancer, most of the time if you live on the surface of Mars it would have to be underground. We will I expect send astronauts to Mars someday because it sounds so neat. People say look, said in a single day a geologist could look in a day and do what the rovers have done in six months. But you can send thousands of rovers for the price of sending a human being. They don't mind being alone for years and years and years. For me a thousand rovers is better than one human when it comes to the science. As far as the adventure, well, that's different. That's a whole different question. I think ultimately we'll do it because it excites people, going boldly where they have not gone before.

TED SIMONS: And they know they had never –
LAWRENCE KRAUS: I talked to Buzz Aldrin about this, he was a big fan of one-way missions. He said it depends on how you send it. If you are the President saying I am going to create on another planet -- We'll see, I think it's all in the future. The likelihood of going to Mars in the near term assess Saint Paul and so and a halfist's. There's no way I can see any business plan that allows a $100 billion project that takes two decades to do. It's the government and it's going to take a long time.

TED SIMONS: You've got about two minutes left. I want to talk about something very current, light from the big bang.

LAWRENCE KRAUS: The fact that two telescopes were used to look back at some of the earliest galaxies, and they saw one galaxy at a distance of about 800 million years old, and there's this blue cloud, I think 7 to 10 times brighter than any other, maybe the first stars that ever formed. Ours is made up of lots of elements, hydrogen and helium, but other major elements as well. In the big bang the only ones that were integrating are hydrogen and helium. If you work it out and you have 200 times the mass. Then burning off like crazy in less than a billion years. We've been looking for where the first storms would form and create the elements later on for mother stars. These people have seen the first generation of stars that ever formed. People thought maybe 200 million years, maybe these are stragglers that are just there. But it could be the signal that we've been lucky.

TED SIMONS: Very quickly, could they be black holes?

LAWRENCE KRAUS: The interesting question is maybe they didn't just form a big star. The answer is we don't know because no one knows about the signal. The search for the early galaxies to look for the first generation of stars, and we at ASU are involved in all that.

Good to be back in nice warm Phoenix.

TED SIMONS: Thank you so much. Thursday on "Arizona Horizon," Secretary of State Michele Reagan will join to us discuss a variety of issues involving her office. And we'll hear from both sides on the concept of a living wage. That's at 5:30 and 10:00 on the next "Arizona Horizon" Arizona. Thank you so much for joining us, you have a great evening.

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