Cosmic Queries: New Discoveries

From cosmic bruises to ion drives to quantum entanglement: astrophysicist Neil deGrasse Tyson and co-host Eugene Mirman answer your questions about recent scientific discoveries.

Speaker names marked ? are inferred from speaking time and the show’s known hosts — they are not voice-verified.

• 0:01Neil deGrasse Tyson?

  Welcome to StarTalk, your place in the universe where science and pop culture collide. StarTalk begins right now.

• 0:21Neil deGrasse Tyson?

  This is StarTalk. I'm your host Neil deGrasse Tyson, your personal astrophysicist. In studio with me, the one, the only, the inimitable Eugene Mirman. Eugene, you're such a reliable guy for us.

• 0:34Eugene Mirman?

  I love coming in. That's how I know so much about space now.

• 0:37Neil deGrasse Tyson?

  This is gonna be our Cosmic Queries edition.

• 0:40Eugene Mirman?

  Yes.

• 0:40Neil deGrasse Tyson?

  Love these. It's our gift back to our listeners and our fans who send us questions and they're so avid. I mean, and we can't just let those go.

• 0:50Eugene Mirman?

  Yeah.

• 0:50Neil deGrasse Tyson?

  We just gotta bring them in.

• 0:51Eugene Mirman?

  We need to help them understand the world and the space.

• 0:54Neil deGrasse Tyson?

  So Cosmic Queries edition.

• 0:56Eugene Mirman?

  All right.

• 0:57Neil deGrasse Tyson?

  And for this one, we're talking about, what's the theme?

• 0:59Eugene Mirman?

  New discoveries, things in the news.

• 1:01Neil deGrasse Tyson?

  In the news.

• 1:02Eugene Mirman?

  Science in the news, ripped from the headlines, science, law and order.

• 1:05Neil deGrasse Tyson?

  I haven't seen any of these questions before, so I might not know some of the answers. I'll just tell you.

• 1:10Eugene Mirman?

  Yeah.

• 1:10Neil deGrasse Tyson?

  Skip it, go on to the next one.

• 1:12Eugene Mirman?

  If you don't know something.

• 1:13Neil deGrasse Tyson?

  Yeah, so let's go for it.

• 1:16Eugene Mirman?

  Megan wants to know, what number am I thinking of? No, Megan wants to know, I recently read that MIT folks found bruises in the cosmic background radiation indicating regions where our universe may have hit other universes. How can our universe expand forever if there are other universes outside it?

• 1:35Neil deGrasse Tyson?

  Yeah, so you can expand forever. And if you're in a higher dimension, if you're embedded in a higher dimension, you can expand without anybody ever bumping into anybody. For example, consider a rubber sheet. And you take a rubber sheet and stretch it. You can make it as big as you want. You can take another rubber sheet, put it one inch below that one, and stretch that as big as you want. Two rubber sheet universes stretching forever, never colliding, never touching.

• 2:00Eugene Mirman?

  But if it was at a slight angle, it would hit each. I think what she's saying is...

• 2:04Neil deGrasse Tyson?

  Well, what I'm saying is, yes, if it's fine, it would hit, but you can even in an even higher dimension. How many dimensions you embedded in?

• 2:11Eugene Mirman?

  Yeah.

• 2:11Neil deGrasse Tyson?

  A two dimensional rubber sheet in three dimensions? Yeah, if you tip it, it'll get embedded in four dimensions. You can do this forever.

• 2:18Eugene Mirman?

  Yeah.

• 2:18Neil deGrasse Tyson?

  That's A. B, if you're near another universe, gravitational effects permeate the boundaries of your universe and can touch another universe. So in principle, we could feel the effects of other universes embedded in this higher dimensional space that could be simply the meta fabric of the multiverse.

• 2:41Eugene Mirman?

  Right. So you're saying ghosts are real and they're people in another universe that happen to live inside your house in a rubber sheet universe?

• 2:48Neil deGrasse Tyson?

  Except I never understood why the ghosts that people see are not naked because it means their clothing is ghost as well.

• 2:53Eugene Mirman?

  Yeah.

• 2:53Neil deGrasse Tyson?

  Yeah. Why are they wearing clothing at all?

• 2:55Eugene Mirman?

  I think because they might be make believe.

• 2:58Eugene Mirman?

  That's just one theory I have.

• 3:00Neil deGrasse Tyson?

  Plus your outer skin layer is dead and your hair is dead. I mean, if you're a living ghost, you're, why do they have?

• 3:06Eugene Mirman?

  I don't know. And it's all really little, it's scary little girls. The whole thing doesn't really come together.

• 3:12Neil deGrasse Tyson?

  Next question.

• 3:13Eugene Mirman?

  Okay, uh, Silico asks, uh.

• 3:17Neil deGrasse Tyson?

  Is that the cousin of Magneto?

• 3:19Eugene Mirman?

  I don't know. Yeah. It's a bunch of nonsense stuff. And now it says Alex from California. That makes more sense. He's asking, could in the near future, entangled particles be used for non-delayed communication over vast distances?

• 3:32Neil deGrasse Tyson?

  Yeah. So what happens in quantum physics is that particles can know about each other instantaneously at a distance.

• 3:39Eugene Mirman?

  Mm hmm.

• 3:40Neil deGrasse Tyson?

  So that if you perturb one particle, the other particle, which is entangled with it, can alter it instantaneously faster than the speed of light.

• 3:47Eugene Mirman?

  Twins across, across the world.

• 3:49Neil deGrasse Tyson?

  Exactly. I mean, if you want to get sort of macroscopic about it, yeah. Twins in the sense that one has a thought and so is another.

• 3:55Eugene Mirman?

  The other's like, why does my hand hurt? And it's like, cause your twin hit her hand in the door.

• 3:58Neil deGrasse Tyson?

  Exactly. So, or at least as people report, so.

• 4:02Eugene Mirman?

  Yeah, I'm not giving fake science here. I get that it's not real.

• 4:06Neil deGrasse Tyson?

  So entangled particles communicate with one another faster than the speed of light. It's very well understood. It's a quantum.

• 4:12Eugene Mirman?

  And that's a thing that's real.

• 4:13Neil deGrasse Tyson?

  That's real.

• 4:13Eugene Mirman?

  It's not just like a dream everyone has.

• 4:15Neil deGrasse Tyson?

  That's real. The problem is if you want to do that in any way that matters to life. Like, you know, I don't know, there are two worlds, there's a microscopic world and a macroscopic world. When you talk about macroscopic things and you want them to behave in a microscopic way, you want them to behave quantum mechanically, it all gets sort of averaged out. The problem is you can have particles entangled, but so are the particles trying to entangle in a different way, at a different time, and all this becomes a one macroscopic classical physics problem, where nobody is doing weird things like what happens in quantum physics. So the big challenge is, can you bridge the gap between the way matter behaves at its smallest scales,

• 4:57Neil deGrasse Tyson?

  exhibiting the tenets of quantum physics and the large scales that we are familiar with interacting? And that it's no known way you can end up doing that. And so, right now, it's a quantum mechanical curiosity.

• 5:09Eugene Mirman?

  Okay.

• 5:10Neil deGrasse Tyson?

  Yeah, you got it. But great question.

• 5:11Eugene Mirman?

  All right. So here's, this is from Michael. I heard that NASA has recently shut down an ion engine. Can you explain what this ion engine is and does and potential, and the potential benefits?

• 5:23Neil deGrasse Tyson?

  Yeah, so an ion drive is what we think of them as. You know, the big challenge here is chemical rockets are just...

• 5:30Eugene Mirman?

  Ugh, they're so...

• 5:31Neil deGrasse Tyson?

  They're so yesterday.

• 5:32Eugene Mirman?

  Yeah.

• 5:32Neil deGrasse Tyson?

  They're so nineteen, they're so Robert Goddard.

• 5:34Eugene Mirman?

  If somebody could build it in a farm and make a movie about it. It's that easy and that dull and old.

• 5:40Neil deGrasse Tyson?

  And the problem is not that there was anything wrong with, with chemical rockets when they were invented. It's just that a hundred years later, you think we'd be doing a little better now.

• 5:49Eugene Mirman?

  Yeah.

• 5:49Neil deGrasse Tyson?

  Right? And we're not. We have something more modern, more efficient than a chemical rocket. And a chemical rocket is all the rockets you've ever seen.

• 5:56Eugene Mirman?

  Yeah.

• 5:56Neil deGrasse Tyson?

  All of them are chemical rockets. They use chemistry, the energy contained in, in molecules.

• 6:03Eugene Mirman?

  Sounds like something that Thomas Edison would have done. And how far have we come from that guy, that dullard?

• 6:10Neil deGrasse Tyson?

  So, you have this, these atoms and they come together as a molecule. And there is energy to be released if you break apart the molecule. That's how all this works. That's how gunpowder works. That's how nitroglycerin works. That's how the rocket engines or the shuttle works. So it's all chemical energy being released, giving you propulsion. drives are much more efficient. So the, what we call the impulse, the, the little push, the nudge that the rocket fuel gives you is much higher compared with the mass of fuel you ejected.

• 6:43Eugene Mirman?

  Mm hmm.

• 6:44Neil deGrasse Tyson?

  Right. You look at the, the, the, the, the shuttle rockets and the plume that comes out when this thing launches, the mass of that fuel is huge. It is most of the mass of the shuttle apparatus.

• 6:56Eugene Mirman?

  Is that fuel?

• 6:57Neil deGrasse Tyson?

  Is fuel.

• 6:58Eugene Mirman?

  So what's, so what is an ion engine though? What is it?

• 7:00Neil deGrasse Tyson?

  An ion engine, you, what, what happens is you have a, a gas and you ionize it. So you strip electrons off of it. You need an energy source to do that. Okay. And then you set up a device. You, you set up a device that ejects these little particles out the back of the ship or whatever, there's the opposite direction you want to travel. And so what this, what's called a specific impulse, the impulse from the one little particle that comes out and the, the recoil of your ship is very high compared with the mass that came out. Very, it's a very efficient.

• 7:30Eugene Mirman?

  So when you strip electrons, it creates way more energy and, and.

• 7:33Neil deGrasse Tyson?

  When you strip electrons and then eject them out of one side, which you can do with magnetic fields and this sort of thing. It, at the, the response to your craft is, is awesome. The, the problem is it's not very large. It's efficient, but it's not very large. So you can only redirect spacecraft very slowly.

• 7:49Eugene Mirman?

  Could you make a gun with it? Could you make an ion gun that shot?

• 7:52Neil deGrasse Tyson?

  When we come back, we'll find out if you can make ion.

• 7:56Eugene Mirman?

  Build this.

• 7:56Neil deGrasse Tyson?

  Guns, StarTalk Radio Cosmic Queries Edition will be right back.

• 8:18Neil deGrasse Tyson?

  We're back. StarTalk Radio, I'm here Neil deGrasse Tyson with Eugene Herman.

• 8:23Eugene Mirman?

  So we were talking about an ion engine, but that made me go, can you make an ion gun?

• 8:26Neil deGrasse Tyson?

  Yeah, you know, with the, the questioner asked an honest, simple, innocent question about propulsion through the universe. You have to take the idea and make a gun out of it.

• 8:35Eugene Mirman?

  Uh, would it be better if I said an ion sword? That sounds less reasonable.

• 8:40Neil deGrasse Tyson?

  In principle, I suppose you can make it, it would be a plasma gun is what it is. You'd send plasma out at somebody.

• 8:47Eugene Mirman?

  That sounds great. That sounds like a great plan.

• 8:51Neil deGrasse Tyson?

  If the plasma is hot enough, you can vaporize their clothing and then their skin. Yeah, in principle.

• 8:57Eugene Mirman?

  You make it sound so evil.

• 8:59Neil deGrasse Tyson?

  And this will be like on the list of the, you know, protected by the Second Amendment.

• 9:04Eugene Mirman?

  Yes, will be. Yes, exactly. They never envisioned the ion plasma gun that so many hunters bears with.

• 9:11Neil deGrasse Tyson?

  The founding fathers.

• 9:13Eugene Mirman?

  Yeah.

• 9:14Neil deGrasse Tyson?

  We are constitutionally protect your right to arm yourself with a plasma gun.

• 9:20Eugene Mirman?

  Okay, Jim Erickson, he asks, can NASA give coordinates and a precise trajectory to launch the corrupt and or science ignorant politicians into a black hole? I think even I could answer that. The answer is yes. NASA could give the coordinates.

• 9:35Neil deGrasse Tyson?

  The corrupt or ignorant politicians?

• 9:37Eugene Mirman?

  But the question is actually, can NASA give the coordinates and a trajectory? So it's like he has a rocket that he just needs.

• 9:43Neil deGrasse Tyson?

  Oh, he doesn't need the rocket?

• 9:44Eugene Mirman?

  It sounds like he has the rocket, but what he needs is just, he's like, I'm not sure where to send it to the black hole. Like, it wouldn't be enough to just send them into space with no way back.

• 9:53Neil deGrasse Tyson?

  We've got coordinates of very many black holes in the galaxy. They're discovered by X-ray telescopes. And so the Chandra X-ray Telescope, which is a telescope of magnitude Hubble, except it specialized in X-rays, not visible light. So, but people are not as cozy with X-rays as they were with Roy G. Biv, red, orange, yellow, green, blue, indigo, violet. So, yeah, we have coordinates of black holes and there's a super massive one in the center. So if you wanted to send people to it, that's how you do it. However.

• 10:23Eugene Mirman?

  Yes, what's the limitation? There's always a catch with you.

• 10:27Neil deGrasse Tyson?

  Is the more we want to send our politicians who are corrupt or ignorant. I mean, at the end of the day, in a democracy. Who voted for them? Okay, so, so maybe it is the population we should be sending into black holes and not the politicians until the population learns how to elect.

• 10:45Eugene Mirman?

  Right.

• 10:46Neil deGrasse Tyson?

  A literate, scientifically literate politician. So I've stopped blaming politicians long ago.

• 10:50Eugene Mirman?

  And blame the voters.

• 10:52Neil deGrasse Tyson?

  And as, just as an educator, my target is the electorate, not the politicians. That's, that's all.

• 10:57Eugene Mirman?

  Right, right. We have a call. Uh, we actually have a caller.

• 11:00Neil deGrasse Tyson?

  A caller, excellent.

• 11:01Eugene Mirman?

  Yeah, let's do it. Let's take this call from San Diego.

• 11:04Neil deGrasse Tyson?

  Okay, and who is it?

• 11:05Speaker 02

  This is Jeff from San Diego.

• 11:07Neil deGrasse Tyson?

  Uh, Jeff, hi, welcome to StarTalk Radio Cosmic Queries Edition.

• 11:10Eugene Mirman?

  Mm-hmm.

• 11:11Neil deGrasse Tyson?

  So what do you got?

• 11:12Speaker 02

  So my nine-year-old daughter and I want to know, now that curiosity's been on Mars for over a year.

• 11:17Neil deGrasse Tyson?

  Wait, that sounds like it's really his nine-year-old daughter who wants to know.

• 11:20Eugene Mirman?

  Yeah, yeah.

• 11:20Neil deGrasse Tyson?

  He's trying to slide in on her.

• 11:21Eugene Mirman?

  Or he, yeah.

• 11:23Neil deGrasse Tyson?

  On her genius.

• 11:24Eugene Mirman?

  Yeah.

• 11:25Neil deGrasse Tyson?

  Okay, Jeff.

• 11:26Speaker 02

  So now that curiosity's been on Mars for over a year.

• 11:29Neil deGrasse Tyson?

  Yeah.

• 11:30Speaker 02

  And they've found that Mars had favorable conditions for microbial life billions of years ago.

• 11:35Neil deGrasse Tyson?

  Yeah.

• 11:35Speaker 02

  I threw in the microbial life part. Billions of years ago, do you think we'll find evidence of actual life first on Mars on one of the new Earth-like planets that they keep finding?

• 11:44Neil deGrasse Tyson?

  Oh, yeah, great question.

• 11:46Eugene Mirman?

  Yeah.

• 11:46Neil deGrasse Tyson?

  So if we find life on Mars, it's not going to be like a civilization who's beaming radio waves to us.

• 11:51Eugene Mirman?

  Right, it won't be someone playing our Elvis record.

• 11:54Neil deGrasse Tyson?

  It's backwards.

• 11:55Eugene Mirman?

  Backwards. Yeah, so they don't get how it's meant to be heard.

• 11:59Neil deGrasse Tyson?

  Yeah, so on Mars, it's the microbial life that we're eager to find and to the biologist, I mean, I'm not a biologist, but I think I can speak for them when I say, if they find any kind of life at all, whether or not we deem it intelligent, it would be an amazing discovery, the greatest discovery in the history of biology, to find life that had formed independently of life on Earth.

• 12:18Eugene Mirman?

  Right.

• 12:18Neil deGrasse Tyson?

  Uh, on Mars or anywhere else.

• 12:20Eugene Mirman?

  If there was water, it's sort of likely, right?

• 12:22Neil deGrasse Tyson?

  Well, every water on Earth, every place there's liquid water on Earth, there is life, even the Dead Sea.

• 12:28Eugene Mirman?

  Yeah.

• 12:29Neil deGrasse Tyson?

  Where people just didn't have microscopes to see life smaller than the resolution limits of their eyeballs. And so they say, therefore it's dead.

• 12:36Eugene Mirman?

  Yeah.

• 12:36Neil deGrasse Tyson?

  No, you just don't know how to see yet. All right, so whereas these exoplanets, these planets that might be in the Goldilocks zones around other stars, if we find life on those. We're not looking at it microbially. I mean, there are tricky ways we can invoke, clever ways we can test to see if it has microbes. We'd be looking at what are called biomarkers. If the microbe emits methane, for example.

• 12:59Eugene Mirman?

  Yeah.

• 13:00Neil deGrasse Tyson?

  Methane is not stable on its own. It has to be churned out by some process. And life is something that can do it. You look for methane in its atmosphere, or oxygen.

• 13:07Eugene Mirman?

  Would we be able to find methane on one of the Kepler's?

• 13:10Neil deGrasse Tyson?

  Uh, with very, uh, careful measurements, we are at the cusp of being able to look at the atmospheric chemistry of planets that are orbiting other stars. So, uh, if we find, I, I think, uh, it's more likely to find it on Mars. We'll find it sooner on Mars than on an exoplanet, just because the technology isn't completely there yet.

• 13:30Eugene Mirman?

  We're there. We're on Mars. We're literally digging things up, eating them. A robot is eating them, trying to figure out if it was once alive.

• 13:36Neil deGrasse Tyson?

  Yeah, we're there. And when you're looking at exoplanets, you gotta be really clever. You have to wait for the planet to pass in front of the host star and look at the light from the host star as it passes through the atmosphere of the host planet. And if the oxygen is there, it takes away certain signature of light from the host planet.

• 13:51Eugene Mirman?

  When you describe this, I can't believe scientists have the patience to do any of this. This is, this is, yeah.

• 13:57Neil deGrasse Tyson?

  Yeah. So, uh, so it's a great question. Uh, uh, tell your daughter, thanks for getting you to call in for.

• 14:03Eugene Mirman?

  Yeah. So tell her probably Mars.

• 14:06Neil deGrasse Tyson?

  Yeah.

• 14:06Speaker 02

  It's worse than that. I lost the bet. She picked Mars.

• 14:09Neil deGrasse Tyson?

  She picked Mars. Excellent. Excellent.

• 14:12Eugene Mirman?

  All right.

• 14:13Neil deGrasse Tyson?

  So thanks, Jeff, for calling in.

• 14:14Speaker 02

  Thank you, guys.

• 14:15Neil deGrasse Tyson?

  All right. Great.

• 14:16Eugene Mirman?

  All right. We got another question. You ready?

• 14:17Neil deGrasse Tyson?

  And these are all from the internet, right? I mean.

• 14:19Eugene Mirman?

  Yeah, these questions are, these ones right now happen to be from Facebook, the website.

• 14:23Neil deGrasse Tyson?

  StarTalkRadio.net. And if you like us on, on Facebook, just like us. Yeah.

• 14:27Eugene Mirman?

  Yeah. Yeah. If you like us in real life, like us on Facebook. I think that's what Neil means.

• 14:32Neil deGrasse Tyson?

  And on Twitter, StarTalkRadio. Yeah, it's all there.

• 14:34Eugene Mirman?

  Uh, okay. Here's a question for, uh, from Erasmo. Can you tell us about gravitational lensing technology for a space telescope? What are the obstacles and how far away are we from develop, deploying?

• 14:48Neil deGrasse Tyson?

  Uh, well, we know of gravitational lenses in space. Einstein, upon discovering that gravity bends space, he hypothesized that a particular configuration of matter could bend space in such a way that it can serve as a cosmic space lens, magnifying stuff behind it in the universe.

• 15:10Eugene Mirman?

  I can't tell if you're making up science fiction or telling me information from science because you really like it's it's just on the border of like, I don't know.

• 15:18Neil deGrasse Tyson?

  It is all.

• 15:19Eugene Mirman?

  Sounds like a ring powered by will.

• 15:20Neil deGrasse Tyson?

  It is all there. And so Einstein made this prediction. It would be 70 years or so, if I can remember my timetables, about 70 years before we would discover the first gravitational lens. And they're all they're all over. They're kind of, you gotta know what you're looking for because the lens can isn't just magnifying stuff in the background. Not all the lenses are perfectly quote shaped to do what a normal lens would do. Some are like funhouse mirrors. So you can take a background galaxy and flip it left, right, up and down, distort it and make the image of the galaxy appear multiple times because of that lens. And so previously, we might have photographed it, but thought it was separate galaxies.

• 16:01Neil deGrasse Tyson?

  It turns out it's one galaxy lensed by one disturbance of spacetime, creating this funhouse image. So our space telescopes have found these gravitational lenses out there in space. These aren't lenses we're making in the neighborhood. No, they're huge scale and they require

• 16:20Neil deGrasse Tyson?

  a distribution of mass that we don't have control over right now.

• 16:23Eugene Mirman?

  So how far of how in how many years do you think we might?

• 16:26Neil deGrasse Tyson?

  Never.

• 16:27Eugene Mirman?

  Never. So around never?

• 16:28Neil deGrasse Tyson?

  You need, you need the mass distribution of what you'd find in a cluster of galaxies.

• 16:33Eugene Mirman?

  Okay.

• 16:34Neil deGrasse Tyson?

  And.

• 16:34Eugene Mirman?

  Sounds unlikely.

• 16:35Neil deGrasse Tyson?

  Unlikely for us. Yeah, but the Borg could do it for sure.

• 16:38Eugene Mirman?

  Sure. Yes.

• 16:39Neil deGrasse Tyson?

  Duh.

• 16:40Eugene Mirman?

  Made up collective. Certainly have the resources.

• 16:45Eugene Mirman?

  All right. And here's another question.

• 16:47Neil deGrasse Tyson?

  Oh, by the way, by the way, gravitational lenses allow us to see farther in the universe than our telescope might otherwise have permitted.

• 16:53Eugene Mirman?

  So they they magnify it?

• 16:55Neil deGrasse Tyson?

  Yeah, they they they help us probe the distant universe, but we don't create them. They just.

• 17:00Eugene Mirman?

  Right. They're there.

• 17:01Neil deGrasse Tyson?

  Nature makes them for us.

• 17:03Eugene Mirman?

  Well, thank you, nature. All right, this one's from Jamie Robertson. Could time have more than one dimension? Just as string theory requires more spatial dimensions than we experience, couldn't it be possible to have more time dimensions than we experience?

• 17:18Neil deGrasse Tyson?

  I so want, I so want time to have more than one dimension. There's nothing compelling that requires us to think that.

• 17:25Eugene Mirman?

  That it does or doesn't?

• 17:27Neil deGrasse Tyson?

  That it does. There's nothing compelling us that requires that we have to think that time has more than one dimension. But if it did, that would just be cool.

• 17:34Eugene Mirman?

  Is it possible?

• 17:35Neil deGrasse Tyson?

  Think about it. So if you, if you go on to one of the time dimensions, time would tick at a particular rate for you.

• 17:41Eugene Mirman?

  In base four.

• 17:42Neil deGrasse Tyson?

  And another dimension, it could tick at a different rate. And if you go in a direction that's a hybrid of each of those two directions, it would, you would then hybridize the rate at which your time unfolds. That's no different from walking. You can go north or you can go east. If you only go north, you're not going east at all.

• 18:01Eugene Mirman?

  Yeah.

• 18:02Neil deGrasse Tyson?

  If you only go east, you're not going, if you go in between, you're going a little bit north. A little, you go north, northeast?

• 18:08Eugene Mirman?

  Yeah.

• 18:08Neil deGrasse Tyson?

  East, south.

• 18:09Eugene Mirman?

  So you're saying there could be time that's going north and time that goes east?

• 18:13Neil deGrasse Tyson?

  In a sense. And then you could pick a trajectory that gets you a little bit of one time and a lot more of another. That would just be kind of interesting. And I don't know quite how to think about that going forward. We're not compelled to do so. When we come back, more StarTalk Cosmic Queries Edition. News ripped from the headlines. See you in a moment.

• 18:50Neil deGrasse Tyson?

  We're back. StarTalk Cosmic Queries Edition. I'm your personal astrophysicist, Neil deGrasse Tyson, in studio with Eugene Mirman, who's reading me questions from the internet, culled from our fanbase, our listeners, and whoever else cared to write in to our website, to Twitter, to a Facebook page, to Google+, to Pinterest, go for it. I haven't seen any of these questions before.

• 19:11Eugene Mirman?

  I don't know how Pinterest works, but I believe you.

• 19:14Neil deGrasse Tyson?

  I haven't seen, I haven't heard, seen or heard any of these questions.

• 19:17Eugene Mirman?

  Okay.

• 19:17Neil deGrasse Tyson?

  And, and the topic is, uh, science ripped from headlines.

• 19:20Eugene Mirman?

  Yes.

• 19:20Neil deGrasse Tyson?

  Yeah, yeah.

• 19:21Eugene Mirman?

  So yeah, so here's a question. This one is from Alejandro. If an ancient civilization in Earth's history had made geostationary satellites, would they still be in orbit today?

• 19:33Neil deGrasse Tyson?

  Yes, there is nothing to uh to interfere with the orbit of a geostationary satellite. It is it is so far out orbiting twenty two thousand miles above Earth's surface.

• 19:46Eugene Mirman?

  Mm hmm.

• 19:47Neil deGrasse Tyson?

  Uh, what would that be in kilometers, I guess?

• 19:49Eugene Mirman?

  Eight. So blatantly wrong.

• 19:53Neil deGrasse Tyson?

  Uh, let's try thirty thousand kilo, no, uh, yeah, about thirty thousand kilometers up.

• 19:57Eugene Mirman?

  Uh huh.

• 19:58Neil deGrasse Tyson?

  Uh, you, if you're that high up, there are no air molecules from our atmosphere to slow you down and decay your orbit and drop you into the Pacific Ocean or anywhere else. So, yes, uh, it'll stay, it's basically will stay in orbit around the Earth forever unless some asteroid or meteor hits it. And but that would be an extraordinary um fact, where the the dynamics are stable, we're good. But that would not be, for me, the most interesting fact here. It would be that we had a civilization.

• 20:27Eugene Mirman?

  Yeah, that had made, that had sent something into space and we haven't found them.

• 20:32Neil deGrasse Tyson?

  Right, and where are they, you know, are they underground? So I would be way more impressed that

• 20:37Eugene Mirman?

  Small people.

• 20:37Neil deGrasse Tyson?

  That such a civilization existed than that they put up a spacecraft.

• 20:41Eugene Mirman?

  Right, right.

• 20:42Neil deGrasse Tyson?

  All right.

• 20:42Eugene Mirman?

  Um, so Ryan has a question. How can the universe be expanding and yet galaxies are swallowing each other? Wouldn't the push be a greater force or it has slowed or has it slowed down?

• 20:53Neil deGrasse Tyson?

  Uh, these people are totally getting them. Excellent, okay, so it turns out you we we're we live in an expanding universe.

• 21:00Eugene Mirman?

  Yeah.

• 21:00Neil deGrasse Tyson?

  And the farther away you are from a neighboring object,

• 21:04Eugene Mirman?

  Mm hmm.

• 21:05Neil deGrasse Tyson?

  the more manifest is the expansion of the universe. So if you are really close, the expansion of the universe is so small as to be swamped by your mutual gravitational attraction. So we and the Andromeda Galaxy,

• 21:20Eugene Mirman?

  Mm hmm.

• 21:20Neil deGrasse Tyson?

  two million light years away, we are falling towards one another, even in the middle of the expansion of the universe, because we are so close

• 21:26Eugene Mirman?

  Yeah.

• 21:27Neil deGrasse Tyson?

  that our speeds and our gravity totally override.

• 21:29Eugene Mirman?

  How close, how how quickly are we falling towards each other? Or slowly, however you want to answer it.

• 21:35Neil deGrasse Tyson?

  Yeah, so you you're worried about the future of Earth.

• 21:37Eugene Mirman?

  Yeah, I'm worried, like, do I have to be worried about, like, Thursday or like, or like, twenty twenty?

• 21:43Neil deGrasse Tyson?

  Yeah, so.

• 21:43Eugene Mirman?

  Is it not climate change, but a falling galaxy that I should be concerned?

• 21:46Neil deGrasse Tyson?

  We will collide. Anywhere between six and eight billion years from now.

• 21:51Eugene Mirman?

  And the sun will die in?

• 21:53Neil deGrasse Tyson?

  Five billion years. Yeah, so the sun is a much bigger issue.

• 21:56Eugene Mirman?

  Yeah, yeah.

• 21:56Neil deGrasse Tyson?

  A concern for you, but presumably by then we'll be able to planet hop, find another solar system. So it's still something to think about, I think. And the reason why I say it's between that period of time, because a galaxy is not a solid, it's not a single point.

• 22:08Eugene Mirman?

  Yeah.

• 22:09Neil deGrasse Tyson?

  In space, it's a huge extended object. So at what point are we colliding?

• 22:13Eugene Mirman?

  It's like polyphonic spree, which is a very big band, trust me.

• 22:15Neil deGrasse Tyson?

  Okay.

• 22:18Neil deGrasse Tyson?

  So it takes a long time for galaxies to actually collide.

• 22:21Eugene Mirman?

  Yeah.

• 22:21Neil deGrasse Tyson?

  Because they're so large and they're huge systems. We'll likely survive that. It'll just be a beautiful train wreck in the sky. Stars are very far apart from one another, so our solar system is likely to stay intact throughout this entire journey.

• 22:34Eugene Mirman?

  Mm hmm.

• 22:35Neil deGrasse Tyson?

  Enjoy the ride.

• 22:35Eugene Mirman?

  All right.

• 22:36Neil deGrasse Tyson?

  Yeah.

• 22:37Eugene Mirman?

  Okay, here's a question. This is one's from Joseph. Is it possible that the universe isn't expanding, but that we're all just shrinking at a constant rate all the way to nothingness? Seriously, wouldn't that look like expansion from our perspective?

• 22:51Neil deGrasse Tyson?

  Wow, that's a great question. I'd have to think about that.

• 22:54Eugene Mirman?

  Sure.

• 22:55Neil deGrasse Tyson?

  If everything was shrinking, hmm.

• 22:59Eugene Mirman?

  But at the rate the universe is expanding, I don't know, it seems like we would have shrunk.

• 23:03Neil deGrasse Tyson?

  Yeah, everything in the universe would have to shrink, but here's the problem. It's the universe itself that's expanding, not the things in the universe.

• 23:10Eugene Mirman?

  Right, right. We're not growing.

• 23:11Neil deGrasse Tyson?

  Right, exactly.

• 23:12Eugene Mirman?

  Except for Americans.

• 23:13Neil deGrasse Tyson?

  So I have to think more about that?

• 23:15Eugene Mirman?

  Yeah.

• 23:16Neil deGrasse Tyson?

  I bet that'd be a fun little sci fi cartoon.

• 23:19Eugene Mirman?

  I'm gonna say physically, based on not knowing anything, I don't think that's the case. But I like the idea.

• 23:25Neil deGrasse Tyson?

  Yeah, it's a fun idea. I have to, let me have to think about that.

• 23:28Eugene Mirman?

  Sure. We'll get back to that.

• 23:31Neil deGrasse Tyson?

  Would we be shrinking?

• 23:32Eugene Mirman?

  Could we be shrinking at a rate that appears that the universe is expanding?

• 23:35Neil deGrasse Tyson?

  Yeah, because all of our measuring rods would have to be shrinking with us.

• 23:38Eugene Mirman?

  Well, we could be, everything could be shrinking.

• 23:40Neil deGrasse Tyson?

  Right, but that'd be an extraordinary thing if it were happening. It's not more extraordinary than just something expanding.

• 23:45Eugene Mirman?

  Yeah.

• 23:46Neil deGrasse Tyson?

  Things expand all the time.

• 23:47Eugene Mirman?

  Yeah.

• 23:48Neil deGrasse Tyson?

  So yeah, pick your extraordinary explanation and, and, and.

• 23:52Eugene Mirman?

  This sounds like something they would have thought in the Middle Ages.

• 23:54Neil deGrasse Tyson?

  I go with, yeah, yeah.

• 23:56Eugene Mirman?

  And then murdered anyone who was like, I don't know, I think it's expanding. Don't be an idiot, we're all shrinking, we're gonna murder you.

• 24:04Neil deGrasse Tyson?

  We're going to liberate your soul.

• 24:05Eugene Mirman?

  Yeah, exactly.

• 24:06Neil deGrasse Tyson?

  That's what that is.

• 24:07Eugene Mirman?

  Yeah, you relax.

• 24:08Neil deGrasse Tyson?

  We've got time for one more in the segment. What do you got?

• 24:09Eugene Mirman?

  Okay, Martin, he's writing from Norway. If warp drive technology actually works and you use it, how do you know where and when to stop?

• 24:18Neil deGrasse Tyson?

  Ooh, no, you'd have a map. You would have the coordinate system of the hyperspace through which you're traveling.

• 24:23Eugene Mirman?

  Yeah.

• 24:23Neil deGrasse Tyson?

  Your normal maps wouldn't work.

• 24:25Eugene Mirman?

  Excellent question. You wouldn't use the Google Maps. You'd be like, this iPhone can't guide me through hyperspace.

• 24:32Neil deGrasse Tyson?

  You need a map that goes to the higher dimension through which you're traveling. And then you can land back where you were going.

• 24:37Eugene Mirman?

  So you'd first map out hyperspace and then you'd probably switch the hyperdrive on.

• 24:41Neil deGrasse Tyson?

  Then you could switch your hyperdrive and land someplace where you need to be.

• 24:44Eugene Mirman?

  And go around rocks and whatever.

• 24:46Neil deGrasse Tyson?

  Yes.

• 24:46Eugene Mirman?

  Are there a lot of rocks in hyperspace?

• 24:48Neil deGrasse Tyson?

  You want to map around asteroids and other destroyed planets. I mean, look at this asteroid belt of Earth. I mean, of the solar system.

• 24:55Eugene Mirman?

  Yeah.

• 24:55Neil deGrasse Tyson?

  There's a lot of rocks there.

• 24:56Eugene Mirman?

  Yeah.

• 24:56Neil deGrasse Tyson?

  So you want to avoid things that could kill you before you got to your destination. Yes.

• 25:00Eugene Mirman?

  Okay.

• 25:01Neil deGrasse Tyson?

  Awesome question that was. This is StarTalk Cosmic Queries Edition. We'll be right back.

• 25:25Neil deGrasse Tyson?

  We're back. StarTalk Radio. Cosmic Queries Edition. Eugene Mirman.

• 25:29Eugene Mirman?

  Okay.

• 25:30Neil deGrasse Tyson?

  What's your Twitter handle?

• 25:31Eugene Mirman?

  Twitter handle is at Eugene Mirman.

• 25:32Neil deGrasse Tyson?

  Eugene Mirman. Okay, gotcha.

• 25:35Eugene Mirman?

  All right.

• 25:35Neil deGrasse Tyson?

  All over it.

• 25:36Eugene Mirman?

  Yeah, get on it, world. Here's a question from Ian. I visited, he writes, I visited the Creation Museum purely out of a sense of mystified curiosity. The recorded narration in their planetarium claimed that contemporary astrophysics predicted that certain stars were older than the known age of the universe and cited this problem as evidence against science and for young Earth creationism. I think this was a real astrophysical problem for a while, but has since been outmoded by better models of stars. I was hoping Neil might tell me a little bit more about the problem and its solution.

• 26:13Neil deGrasse Tyson?

  Which problem? The problem that a creation museum exists at all?

• 26:16Eugene Mirman?

  I think the problem that a creation museum, I think what it is, is it's pointing to some outdated model of understanding science.

• 26:24Neil deGrasse Tyson?

  Okay, so let's unpack all of that.

• 26:26Eugene Mirman?

  Yeah.

• 26:26Neil deGrasse Tyson?

  So, actually I have nothing specifically against a creation museum.

• 26:30Eugene Mirman?

  Sure.

• 26:30Neil deGrasse Tyson?

  Just keep it out of the science classroom.

• 26:32Eugene Mirman?

  Right, right.

• 26:32Neil deGrasse Tyson?

  We live in a free country, people could say whatever you want about whatever.

• 26:35Eugene Mirman?

  Just like the Batman museum is not accurate historically.

• 26:39Neil deGrasse Tyson?

  That's what it means to be free, right? Just don't confuse it with actual science.

• 26:44Eugene Mirman?

  Yeah.

• 26:44Neil deGrasse Tyson?

  The, so back, when was it? In the 90s?

• 26:47Eugene Mirman?

  Mm-hmm.

• 26:48Neil deGrasse Tyson?

  Um, there were measurements, this is before Hubble settled all these questions, the Hubble telescope that is. The, we had measurements of the oldest stars.

• 26:58Eugene Mirman?

  Mm-hmm.

• 26:58Neil deGrasse Tyson?

  And they were coming in, you know, 18 billion years old. And measurements of the age of the universe, that was coming in at about 15 billion years old. So, uh, that was, it was an unsolved problem in astrophysics.

• 27:12Eugene Mirman?

  I know, it sounds like God exists when you say that.

• 27:14Neil deGrasse Tyson?

  You can't be older than your mother, okay? That's the, if you want to get a terrestrial version of that. Each of those are, that was data obtained by completely independent, separate methods.

• 27:25Eugene Mirman?

  Right.

• 27:26Neil deGrasse Tyson?

  So, uh, I was quite happy that they were in the same ballpark, right? 15 billion, 18 billion.

• 27:31Eugene Mirman?

  Yeah.

• 27:31Neil deGrasse Tyson?

  There's a few billion here or there. Uh, cosmically speaking, that difference is small. It's not one that's a thousand times older than the other.

• 27:38Eugene Mirman?

  Yeah.

• 27:38Neil deGrasse Tyson?

  Then somebody's not getting, doing something right, okay? So, a few billion years on 15 billion years was, it was something, it was a problem to be solved. But it made much sexier headlines to talk about than what any, than...

• 27:52Eugene Mirman?

  So scientists were like, this all seems pretty reasonable with more accuracy, we'll figure it out.

• 27:56Neil deGrasse Tyson?

  That's how we were dealing with it and everyone was, oh my gosh! You know, because what they, they weren't considering what we call error bars.

• 28:02Eugene Mirman?

  Mm-hmm.

• 28:02Neil deGrasse Tyson?

  Error bars are you make a measurement and what is the uncertainty of that number? The uncertainty in the 15 billion year age of the, of the universe was plus or minus 2 billion years. You see these error bars now, these uncertainty numbers in, in election polls.

• 28:14Eugene Mirman?

  Yeah.

• 28:14Neil deGrasse Tyson?

  So they became familiar to people, what is the margin of error?

• 28:17Eugene Mirman?

  People understand that it's like, maybe it's 13 billion, maybe it's 17.

• 28:21Neil deGrasse Tyson?

  Maybe it's 17, and now you have the 18 billion year old. A star.

• 28:24Eugene Mirman?

  Yeah.

• 28:24Neil deGrasse Tyson?

  That could be, you know, that was eighteen plus or minus two. So the overlap in that.

• 28:29Eugene Mirman?

  It's fine.

• 28:30Neil deGrasse Tyson?

  It's fine.

• 28:30Eugene Mirman?

  Perfectly reasonable.

• 28:31Neil deGrasse Tyson?

  And.

• 28:31Eugene Mirman?

  So the Creation Museum uses science from the nineties to prove that science is wrong.

• 28:36Neil deGrasse Tyson?

  Well, right, it's all wrong. And the fact is, in a, in a, in a young universe, as what is uh, put forth by a Creation folk.

• 28:47Eugene Mirman?

  Mm-hmm.

• 28:47Neil deGrasse Tyson?

  Uh, that is a universe that's not, it's six thousand years, no more than ten thousand. It's in the, in the thousands.

• 28:53Eugene Mirman?

  Yeah, yeah.

• 28:54Neil deGrasse Tyson?

  Not billions.

• 28:55Eugene Mirman?

  Right, right.

• 28:55Neil deGrasse Tyson?

  So, these are, these are apples and oranges going on here. So, by the way, it's possible to have an error bar, an uncertainty range, that is completely out of whack. That would mean there's a systematic error.

• 29:06Eugene Mirman?

  Right.

• 29:06Neil deGrasse Tyson?

  In your data. Okay?

• 29:08Eugene Mirman?

  Like the way that they thought they created, what, fast tachyons or no?

• 29:11Neil deGrasse Tyson?

  Yeah, that was, yeah, that was, uh, the, felt they'd found particles in the, in the Switzerland.

• 29:17Eugene Mirman?

  Yeah.

• 29:17Neil deGrasse Tyson?

  That were traveling faster than light. And either it was a blunder, or they were actually traveling faster than light. And we've never, ever seen, or measured anything travel faster than light, which meant it was probably a blunder.

• 29:26Eugene Mirman?

  Right.

• 29:26Neil deGrasse Tyson?

  Turned out it was a blunder. Just a complete blunder. And that, that happens. So, uh, so back then, it was a fascinating story. So, right now, the universe is, is about fourteen billion years. The ages of stars all match up.

• 29:38Eugene Mirman?

  Mm-hmm.

• 29:38Neil deGrasse Tyson?

  We have better, uh, measurements of what goes on inside of stars. And that all got resolved. Hubble helped out mightily in that.

• 29:44Eugene Mirman?

  Right.

• 29:45Neil deGrasse Tyson?

  So that, that's all that was going on there.

• 29:46Eugene Mirman?

  So now everything makes perfect sense. All right. So let's, uh, ask another question. Ready?

• 29:52Neil deGrasse Tyson?

  Yeah. Go for it.

• 29:53Eugene Mirman?

  Uh, what is the worst-case scenario for misuse of the warp drive? Dan Owens. What's the worst case? Quickly.

• 30:00Neil deGrasse Tyson?

  Misuse of a warp drive? I don't even know what that means. Anything the warp drive does is gonna be good.

• 30:04Eugene Mirman?

  Yeah.

• 30:04Neil deGrasse Tyson?

  Uh, so misuse would be, you use it to actually travel back in time, and then you

• 30:11Eugene Mirman?

  And then you ruin things.

• 30:12Neil deGrasse Tyson?

  You kill your grandparents, and then you no longer exist.

• 30:15Eugene Mirman?

  Depending who you are, maybe that'd be fine.

• 30:17Neil deGrasse Tyson?

  By the way, you don't ever have to kill your grandparents.

• 30:19Eugene Mirman?

  No, you could just push them down.

• 30:20Neil deGrasse Tyson?

  No, no, yeah, push, just prevent them from ever having met.

• 30:24Eugene Mirman?

  Yeah.

• 30:24Neil deGrasse Tyson?

  You don't have to be bloody about it. You could, in fact, you could go back to your great, great, great, great, great grandparents.

• 30:31Eugene Mirman?

  Mm-hmm.

• 30:31Neil deGrasse Tyson?

  And change the time they had sex. Okay? Then you will not have been born.

• 30:36Eugene Mirman?

  You could just literally jump out of a closet and go, ah! And then you'd probably ruin your whole timeline.

• 30:41Neil deGrasse Tyson?

  Okay, then a different sperm, a different sperm fertilizes the egg and you're never born.

• 30:46Eugene Mirman?

  Perfect.

• 30:46Neil deGrasse Tyson?

  Okay?

• 30:47Eugene Mirman?

  Sounds like a plan.

• 30:48Neil deGrasse Tyson?

  You folks are not creative.

• 30:49Eugene Mirman?

  Yeah.

• 30:50Neil deGrasse Tyson?

  When we come back, more StarTalk Cosmic Queries Edition.

• 31:12Neil deGrasse Tyson?

  We're back. StarTalk Radio. Neil deGrasse Tyson here, Eugene Mirman, Cosmic Queries Edition, the lightning round.

• 31:19Eugene Mirman?

  Yeah.

• 31:19Neil deGrasse Tyson?

  The last round. This is all the stuff we, because I take too long to answer questions.

• 31:23Eugene Mirman?

  Yeah, so we'll go super fast.

• 31:24Neil deGrasse Tyson?

  Go super fast. And I got, let me test the bell? You got it. Okay.

• 31:28Eugene Mirman?

  Nailed it. All right, this is from an 11-year-old from, uh, Shani.

• 31:31Neil deGrasse Tyson?

  Cool.

• 31:31Eugene Mirman?

  She wants to know, how could there be nothing before the Big Bang? Huh?

• 31:37Eugene Mirman?

  Neil?

• 31:37Neil deGrasse Tyson?

  We don't know what was around before the Big Bang, and any respectable scientist will not tell you that there was nothing there.

• 31:43Eugene Mirman?

  So there might have been something.

• 31:44Neil deGrasse Tyson?

  There might have been something, and it could be the, the thriving multiverse that is where just one of the bubbles and it comes and goes? Other bubbles are coming? We don't know. Thank you.

• 31:55Eugene Mirman?

  There was a party.

• 31:56Neil deGrasse Tyson?

  You got it.

• 31:57Eugene Mirman?

  All right, here we go. Theoretically.

• 31:58Neil deGrasse Tyson?

  Oh, by the way.

• 31:59Eugene Mirman?

  Yeah?

• 31:59Neil deGrasse Tyson?

  There's an episode of Family Guy where Stewie takes his time machine and goes back to before the Big Bang.

• 32:05Eugene Mirman?

  And what hap- and yeah, so what happens there?

• 32:06Neil deGrasse Tyson?

  There's nothingness there, just like she said. There's not even space or time.

• 32:11Eugene Mirman?

  I bet there was a Doors concert.

• 32:13Neil deGrasse Tyson?

  And guess what?

• 32:13Eugene Mirman?

  Jim Morrison is there, writing his rhymey poems.

• 32:17Neil deGrasse Tyson?

  And, uh, that came about from a conversation, a lunch I had with Seth MacFarlane.

• 32:21Eugene Mirman?

  Mm-hmm.

• 32:21Neil deGrasse Tyson?

  He just started asking me, "Oh, tell me about the Big Bang, you know, tell me about..." And then I end up with a, with a screen credit as science advisor to this Stewie going back to the beginning of the universe. That was cool. Next.

• 32:32Eugene Mirman?

  Samuel. Okay, he asks, theoretically, could wind travel faster than light?

• 32:36Neil deGrasse Tyson?

  No. Next. No, I mean.

• 32:38Eugene Mirman?

  Yeah, what's the fastest wind could travel?

• 32:39Neil deGrasse Tyson?

  Wind could travel like at the speed of sound, alright? That's basically.

• 32:42Eugene Mirman?

  A little Mach two?

• 32:44Neil deGrasse Tyson?

  Uh.

• 32:44Eugene Mirman?

  I know Mach one, I know, but I'm now upping it. Are you sure?

• 32:47Neil deGrasse Tyson?

  No, no, no, because it has to, can't get past other molecules that are in its way. So you can't have one piece of air travel fat, no.

• 32:54Eugene Mirman?

  Okay.

• 32:55Neil deGrasse Tyson?

  Next.

• 32:55Eugene Mirman?

  Mach one it is.

• 32:56Neil deGrasse Tyson?

  Yeah.

• 32:57Eugene Mirman?

  Okay, Austin asks, Neil, what is your favorite or in your opinion?

• 33:00Neil deGrasse Tyson?

  Well, I should say, so how fast does a molecule move? It bumps into the next molecule and sends that signal to the next molecule. Now, you can move a whole body of air together.

• 33:08Eugene Mirman?

  Yeah.

• 33:09Neil deGrasse Tyson?

  And all the molecules are in there together. I suppose you could accelerate that whole thing.

• 33:13Eugene Mirman?

  Yes.

• 33:14Neil deGrasse Tyson?

  Okay.

• 33:14Eugene Mirman?

  Could you have a hurricane that went faster than Mach one?

• 33:16Neil deGrasse Tyson?

  Oh, hurricane is still moving embedded within another air pocket.

• 33:20Eugene Mirman?

  Oh, sure, sure.

• 33:21Neil deGrasse Tyson?

  So, no.

• 33:22Eugene Mirman?

  Put the wind in a hurricane, sorry, that's what I meant.

• 33:23Neil deGrasse Tyson?

  Yeah, right.

• 33:24Eugene Mirman?

  Okay, great. Is Wizard of Oz realistic? No, um, okay, Austin asks, Neil, what is your favorite or in your opinion, most significant space exploration related discovery of the last year or so?

• 33:34Neil deGrasse Tyson?

  Oh, oh, uh, so I would have to say it was not a discovery. It was the fact that we were able to land Curiosity on Mars in the way we did. It was an engineering Rube Goldberg nightmare that turned out to be completely successful. And that test, all the other ways we can now land on other planetary objects, loved it. It was an engineering achievement, not a scientific achievement.

• 33:56Eugene Mirman?

  Yes.

• 33:57Neil deGrasse Tyson?

  Next.

• 33:57Eugene Mirman?

  Okay, Mike Ward asks, does a black hole die like stars do? If so, what happens? Do they go supernova and expel all the collected matter back into space?

• 34:07Neil deGrasse Tyson?

  What happens in a black hole stays in a black?

• 34:10Eugene Mirman?

  That is, that's accurate though, right?

• 34:11Neil deGrasse Tyson?

  No, uh, black holes actually evaporate, according to a discovery made by Stephen Hawking, uh, the University of Cambridge fame.

• 34:19Eugene Mirman?

  Yeah.

• 34:19Neil deGrasse Tyson?

  Stephen Hawking discovered something, today we call it Hawking radiation. The stuff that goes in a black hole slowly evaporates out of the black hole until the black hole one day disappears entirely.

• 34:30Eugene Mirman?

  And then it's just gone.

• 34:31Neil deGrasse Tyson?

  It's gone completely, correct.

• 34:33Eugene Mirman?

  Nice.

• 34:33Neil deGrasse Tyson?

  It's very slow, takes 10 to the 100 years to evaporate a supermassive black hole. A googol years.

• 34:39Eugene Mirman?

  A googol years.

• 34:39Neil deGrasse Tyson?

  Yeah, yeah.

• 34:40Eugene Mirman?

  Sounds reasonable.

• 34:41Neil deGrasse Tyson?

  Next.

• 34:42Eugene Mirman?

  Okay, if we bring an asteroid for mining into orbit around the moon, will we be able to see it with the naked eye?

• 34:49Neil deGrasse Tyson?

  Depends how big the asteroid is, the one they're thinking of bringing in now, no. That one is about five feet across. You're not seeing that one, but a big one, yeah, bring it, bring it on, watch it, pull out your telescope, check it out.

• 34:59Eugene Mirman?

  And you could watch people mining.

• 35:00Neil deGrasse Tyson?

  If it's big enough, big, what's big enough, you know.

• 35:03Eugene Mirman?

  What's big enough? Two miles?

• 35:04Neil deGrasse Tyson?

  Miles across, miles.

• 35:06Eugene Mirman?

  Miles.

• 35:06Neil deGrasse Tyson?

  You'll do it, but not feet.

• 35:07Eugene Mirman?

  Okay.

• 35:08Neil deGrasse Tyson?

  Yeah.

• 35:09Eugene Mirman?

  How do elements heavier than iron such as uranium form in stars?

• 35:14Neil deGrasse Tyson?

  Oh, uh, yeah, so they don't form in stars, they form when the star explodes, supernovae. There's all kinds of energy to burn, no pun intended, when a star blows up. So iron, which the star makes after it started with hydrogen and helium, and it goes right on up the periodic table to give you iron, to make iron in its center. After iron, the star explodes, that extra energy continues to pump iron and.

• 35:38Eugene Mirman?

  Yeah.

• 35:38Neil deGrasse Tyson?

  Did I actually say?

• 35:39Eugene Mirman?

  Yeah, pump iron.

• 35:41Neil deGrasse Tyson?

  To pump iron.

• 35:41Eugene Mirman?

  Yeah, yeah.

• 35:42Neil deGrasse Tyson?

  It puts particles into, they march into iron to make iron heavier.

• 35:45Eugene Mirman?

  Yeah.

• 35:45Neil deGrasse Tyson?

  Builds all the rest of the elements on the periodic table, right up to uranium. Yes.

• 35:50Eugene Mirman?

  Sounds like, that's, yeah.

• 35:52Neil deGrasse Tyson?

  You got it. Uranium, by the way, named after planet Uranus. Next.

• 35:56Eugene Mirman?

  Nice. Okay, uh, Olivia wants to know, would it be safe to live on a planet or bring a pulsar? If so, would life on the planet be short-lived?

• 36:04Neil deGrasse Tyson?

  Uh, it is not safe, you will die. Pulsars are huge radiation sources and radiation is not compat- High level doses of radiation is incompatible with life.

• 36:15Eugene Mirman?

  Oh, right.

• 36:16Neil deGrasse Tyson?

  Find it, there's plenty of other beautiful stars to, to post your planet. Go. Last question, I don't know, go, go.

• 36:22Eugene Mirman?

  Last question. Okay, uh, huh, all right, last question. Um, we often talk about observed cosmic events having happened in the past, e.g. if a star goes supernova 10,000 light years away.

• 36:34Neil deGrasse Tyson?

  Yeah.

• 36:35Eugene Mirman?

  You hear it described as happening, having happened 10,000 years ago. However, since time is relative, wouldn't this mean that however far away we are from an object, any event, we can't yet observe?

• 36:45Neil deGrasse Tyson?

  If we are not.

• 36:45Eugene Mirman?

  Actually happen.

• 36:46Neil deGrasse Tyson?

  If we are not moving significantly relative to that other object, another star sitting out in space, we're basically in the same time zone. So, uh, we're cool. We don't have to worry about severe time dilation. It's relative when you're moving really fast. Relative to another object, or place, or thing. Mm-hmm. Then you've got these issues. But a star blows up in our, it's our galaxy. We're moving together in this. Yeah. We're fine. We're fine. Okay. We gotta run. That was been StarTalk. Lightning round. Cosmic Queries Edition. Eugene Mirman, thanks as always for being on StarTalk Radio. And I'm Neil deGrasse Tyson, your personal astrophysicist, leading you to keep looking up.