Cosmic Queries: A Stellar Sampling

This week’s show is bursting with conspiracy theories and strange hypotheses, but that doesn’t stop your own personal astrophysicist Neil deGrasse Tyson from dropping some serious science.

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, you're a personal astrophysicist, Neil deGrasse Tyson. I'm here in studio with Eugene Mirman. Eugene, welcome back.

• 0:31Speaker 01

  Great to be here, Neil.

• 0:32Neil deGrasse Tyson?

  That sounded way too rehearsed.

• 0:34Speaker 01

  But it's true, it is great to be here. But you're right, it sounded terrible.

• 0:38Neil deGrasse Tyson?

  We are-

• 0:39Speaker 01

  It sounded like a fake announcer.

• 0:40Neil deGrasse Tyson?

  We are in a Cosmic Queries edition.

• 0:42Speaker 01

  Yeah.

• 0:43Neil deGrasse Tyson?

  That's one of my favorite kinds of StarTalk. And this one, people writing questions, and this is the Grab Bag edition.

• 0:49Speaker 01

  This is the Grab Bag of all sorts of questions.

• 0:51Neil deGrasse Tyson?

  All sorts of, we collect them in the bottom of the bin, and we still think about you. These are questions from all of our fans and listeners.

• 0:57Speaker 01

  Yeah, I mean, this is literally from Denmark. Why would you even bother? Merlin, this is what Merlin asked.

• 1:04Neil deGrasse Tyson?

  Merlin from Denmark.

• 1:05Speaker 01

  I know.

• 1:05Neil deGrasse Tyson?

  Okay, cool, let's do it.

• 1:07Speaker 01

  "I recently found an article describing a relatively recently found quasar cluster, which apparently is too big to exist in the universe, according to our current state of understanding. I am wondering now, of course, how an object could be, even be too large for the entire universe, and also what that exactly means for our understanding of the cosmos."

• 1:29Neil deGrasse Tyson?

  No, so that's a great question. So I think there's a mix-up of information there. So if there's an object, you have like galaxies out there, right? And then you have like pairs of galaxies, and they know about each other because they orbit one another. They're gonna have clusters of galaxies, and they orbit like a bee's in a hive would. And so, so you can see that galaxies can know about the existence of other galaxies that are nearby, and they create what we call a cluster. Now, if you have a cluster of quasars-

• 1:59Speaker 01

  Yeah.

• 1:59Neil deGrasse Tyson?

  -and they know about each other, but they're too far away from one another for the age of the universe to have allowed them to know about one another at the time they were created, that's a problem.

• 2:14Speaker 01

  Yeah, so it's definitely a problem.

• 2:16Neil deGrasse Tyson?

  So in other words, it's a coherent structure.

• 2:19Speaker 01

  Uh huh.

• 2:20Neil deGrasse Tyson?

  That is larger than the universe at the time would have allowed to have existed.

• 2:25Speaker 01

  Right, but now it's fine.

• 2:27Neil deGrasse Tyson?

  No, well, now it would have been fine, but back then we're talking about quasars in the early universe.

• 2:30Speaker 01

  Oh.

• 2:31Neil deGrasse Tyson?

  The early universe back then, the universe was smaller.

• 2:33Speaker 01

  It was the size of like a pan, a size of a Marshall's.

• 2:36Neil deGrasse Tyson?

  Pick a time and any, pick a time and we can find a time in the universe where, pick a size.

• 2:42Speaker 01

  Yeah.

• 2:42Neil deGrasse Tyson?

  There's a time in the universe when it was that size.

• 2:43Speaker 01

  Marshall's.

• 2:44Neil deGrasse Tyson?

  A Marshall's, yes. A marble, yes. An atom, yes. A football stadium, yes.

• 2:50Speaker 01

  I see.

• 2:51Neil deGrasse Tyson?

  So, so it's, so it's a challenge when you have this. It's, you know, the universe brims with mysteries. We don't have it, we don't have answers to it.

• 2:58Speaker 01

  Name of, of your band? Um, all right, here's a question from, uh, Nick. Uh, uh, Christoph Wetterich, a theoretical physicist at the University of Heidelberg in Germany.

• 3:10Neil deGrasse Tyson?

  If he's a theoretical physicist, he should have no questions for me whatsoever.

• 3:13Speaker 01

  Well, it's too late. This guy's quoting him. It's too late for me.

• 3:16Neil deGrasse Tyson?

  Oh, he's quoting the other guy?

• 3:17Speaker 01

  Yeah, yeah. Oh, sorry, Nick. Oh, yeah, yeah. No, Nick is like, expanding universe? And then he, and then this is the message. Christoph, a theoretical physicist at the University of Heidelberg in Germany, has recently.

• 3:29Neil deGrasse Tyson?

  That would be Heidelberg.

• 3:30Speaker 01

  Yeah, I'm just testing you.

• 3:32Neil deGrasse Tyson?

  Okay.

• 3:32Speaker 01

  Uh, has recently proposed an idea that the universe isn't expanding, but instead gaining mass. If the entire universe is gaining mass at the same proportions, it makes his theory impossible to test, though it remains mathematically possible. Nature News ran the article with a couple of opinions. Cosmologist Hongong Sheng Zhao, who thought it should be entertained and Daish Ashfordi, an astrophysicist in Canada who preferred the standard Occam razor approach. Have you read this paper?

• 4:14Speaker 01

  Whether you have or have not, what are your thoughts on or initial reaction to it?

• 4:21Neil deGrasse Tyson?

  Okay.

• 4:21Speaker 01

  Thank you for having me read all these. Names that I have tried to do justice to.

• 4:27Neil deGrasse Tyson?

  But you didn't, you didn't even get the city right. So.

• 4:29Speaker 01

  Yeah. Hey, I, yeah, but that's because I was terrified that I was gonna say Hong Kong, Zheng Zhao incorrectly.

• 4:35Neil deGrasse Tyson?

  So what we have going on here is a new idea that someone puts forth that could explain what we already know. To be true, but in a new and novel way, right? There's a time honored history of this going on in, in the sciences. In fact, Copernicus. Who put the sun back in the middle of the known universe, turning our, our geocentric. World into a heliocentric world. His book. Called The Revolution of Us. That book, which is one of the most coveted books in the history of publishing. That goes for millions of dollars at auction. If you want to pick up one from the original first.

• 5:14Speaker 01

  I would love to. Maybe I'll start a Kickstarter to buy it.

• 5:19Neil deGrasse Tyson?

  The original first edition, that idea was so heretical to put the sun in the middle and not the earth. It is clear and obvious from any read of the Bible that earth is in the middle of all motion. And everything goes around the earth. That's how any movement is described. And earth is stationary to sort of say something that's not that is heretical and at the time punishable by. By. Trial and, and the inquisition. So at the beginning of it, there's a disclaimer. And the disclaimer not written by Copernicus, it says, this is probably not true. But it makes the math a little easier. So for that reason alone, it's worth publishing.

• 6:01Neil deGrasse Tyson?

  So that the mathematicians can calculate where the planets are in the night sky.

• 6:06Speaker 01

  That's a great way around it.

• 6:07Neil deGrasse Tyson?

  So the point is, if you have a new idea. It could be completely radical from what was prevailing at the time and. It could be right, it could be wrong. You don't, you, first you want to make sure it doesn't predict something that you already know is not true. And you want it to predict something that you haven't discovered yet. And that'll give you, that'll give you confidence that it's a real idea. And it's not just exactly mapping onto what you already know is true. If that's all it is, it's not useful. It's just somebody else's other idea. And you don't want to turn it into a, a, a rigid.

• 6:37Speaker 01

  Just a big idea party.

• 6:39Neil deGrasse Tyson?

  A, a rigid Kipling just so story. It was how the leopard got the spots. It got before this way. And here's how the elephant got its trunk. You could just come up with another explanation.

• 6:47Speaker 01

  Right.

• 6:48Neil deGrasse Tyson?

  That doesn't make it right.

• 6:49Speaker 01

  It's just another explanation.

• 6:51Neil deGrasse Tyson?

  Right, and it's got to survive.

• 6:52Speaker 01

  You're not a fan of multiple origin stories?

• 6:54Neil deGrasse Tyson?

  No, you want to make a prediction that we can test it. And if the prediction fails, then we discard the idea. So I haven't, I don't know the idea well enough to know how, what kind of predictions it makes. If it makes no predictions, it's not useful to anyone.

• 7:07Speaker 01

  Right.

• 7:08Neil deGrasse Tyson?

  Not anyone scientifically.

• 7:09Speaker 01

  Sounds like you're not a huge fan of theoretical physicists?

• 7:11Neil deGrasse Tyson?

  No, no, that's why.

• 7:12Speaker 01

  Are they're fine? On a scale of one to 10, where would you put them?

• 7:15Neil deGrasse Tyson?

  God, they're 11.

• 7:18Speaker 01

  That's a very.

• 7:19Neil deGrasse Tyson?

  No, they're good, we need.

• 7:20Speaker 01

  Disingenuous 11.

• 7:22Neil deGrasse Tyson?

  My wife is a mathematical physicist.

• 7:23Speaker 01

  Okay.

• 7:24Neil deGrasse Tyson?

  Got to say nice things.

• 7:25Speaker 01

  Okay, right, I don't want to ruin your marriage.

• 7:27Neil deGrasse Tyson?

  Yeah.

• 7:28Speaker 01

  Um.

• 7:28Neil deGrasse Tyson?

  What else you got?

• 7:29Speaker 01

  Okay, uh.

• 7:31Neil deGrasse Tyson?

  Well, is it a long question because we're running out of time in this segment?

• 7:34Speaker 01

  Uh, yeah, it's, it's, it's longer than the nine seconds. You could do an outro.

• 7:38Neil deGrasse Tyson?

  Okay. You are listening to StarTalk Radio Cosmic Queries Edition. I'm here with Eugene Mirman, we'll be right back.

• 8:04Neil deGrasse Tyson?

  We're back, StarTalk Radio Cosmic Queries Edition. Grab bag, stuff we found at the bottom of the bin.

• 8:09Speaker 01

  Yeah.

• 8:10Neil deGrasse Tyson?

  But.

• 8:10Speaker 01

  Bottom of the bin questions.

• 8:11Neil deGrasse Tyson?

  Every question matters.

• 8:12Speaker 01

  Each one from a conspiracy nut.

• 8:15Speaker 01

  Here it is.

• 8:16Neil deGrasse Tyson?

  There are no conspiracy nuts who listen to StarTalk radio.

• 8:18Speaker 01

  No, there aren't. There are people with valid, the valid question.

• 8:21Neil deGrasse Tyson?

  Alright, so what do you got?

• 8:22Speaker 01

  Gareth asks, I've read some theories that HARP can be used to manipulate the weather. Is this possible?

• 8:27Neil deGrasse Tyson?

  Yeah, HARP is a high altitude.

• 8:32Speaker 01

  Radio, pension.

• 8:35Neil deGrasse Tyson?

  I always forget, I always forget the acronym.

• 8:37Speaker 01

  Yeah.

• 8:37Neil deGrasse Tyson?

  Uh, there are people who are sure that the government is stockpiling aliens and controlling everything about anything we would ever think about, and they clearly have never worked for the government because the level of incompetence in the government.

• 8:50Speaker 01

  Inefficiency.

• 8:50Neil deGrasse Tyson?

  And inefficiency.

• 8:51Speaker 01

  Yeah.

• 8:52Neil deGrasse Tyson?

  Knows no bounds.

• 8:54Speaker 01

  Yeah.

• 8:54Neil deGrasse Tyson?

  For starters.

• 8:55Speaker 01

  It's true that you could manipulate the weather like they did during the Olympics in China. Like, it's not that you can't manipulate the weather, it's that whether you would really have any serious control.

• 9:04Neil deGrasse Tyson?

  Well, weather happens in many places, so it's, it, it comes about from the heat balance, from the energy coming from the sun, what it reflects off of, what it gets absorbed by, what the upcurrents do, what the downdrafts do, what the rotation of the earth is doing, all of this factors in. And so I have not been convinced by any of the reports to suggest that experiments in the upper atmosphere, physics experiments.

• 9:28Speaker 01

  Yeah.

• 9:28Neil deGrasse Tyson?

  Are having any effect on our weather whatsoever.

• 9:31Speaker 01

  Right.

• 9:31Neil deGrasse Tyson?

  And, and it would be, and it would be tragic if we wanted to say, oh, that's why it's getting hotter in the world, okay? Because there's some experiment happening. It would, that would be tragic because we would be missing the 900 pound gorilla in the room.

• 9:47Speaker 01

  Right. And then, but can you?

• 9:49Neil deGrasse Tyson?

  The, the, the carbon dioxide gorilla, yes.

• 9:51Speaker 01

  Yes, the 900 pound carbon dioxide gorilla. Alright, uh, here's another question.

• 9:55Neil deGrasse Tyson?

  By the way, I don't think gorillas can weigh 900 pounds.

• 9:58Speaker 01

  Is that true?

• 9:59Neil deGrasse Tyson?

  Yeah, I don't, the biggest one I've seen, so not 900 pounds, 500 pounds, yeah. Not 900. So 900 pound elephant.

• 10:04Speaker 01

  Like a pumpkin, I bet there's like a pumpkin that someone has made. With a gorilla like a 500 gorilla, holding a 400 pound pumpkin.

• 10:12Neil deGrasse Tyson?

  That would work, yes.

• 10:13Speaker 01

  That would be in the room, which would also should attract attention. Um, here's the question, I don't know who it's from.

• 10:18Neil deGrasse Tyson?

  Yeah.

• 10:19Speaker 01

  Is it possible to somehow direct pollution through our atmosphere and dispose of it in space? All without harming our atmosphere. Love your show, by the way.

• 10:26Neil deGrasse Tyson?

  Oh, thank you. It depends on what kind of pollution you're talking about.

• 10:29Speaker 01

  Dust.

• 10:30Neil deGrasse Tyson?

  So what you're saying is rather than pollute your rivers or your oceans.

• 10:33Speaker 01

  Yeah.

• 10:34Neil deGrasse Tyson?

  You want to pollute the space environment.

• 10:35Speaker 01

  Well, since it wouldn't be, since we'll throw it into space, throw it in.

• 10:39Neil deGrasse Tyson?

  Well, you would, well, you'd wanna actually get rid of it. I, you drop it into a black hole, drop it down into the sun.

• 10:45Speaker 01

  Yeah.

• 10:45Neil deGrasse Tyson?

  You'd wanna actually remove the thing entirely.

• 10:48Speaker 01

  But what was, would it matter to throw it into space? Like, would that be bad to someone?

• 10:51Neil deGrasse Tyson?

  You have to calculate the energy it takes to throw it into space versus the energy it takes to completely break it down.

• 10:57Speaker 01

  On earth.

• 10:58Neil deGrasse Tyson?

  On earth into some non-pollutant.

• 11:00Speaker 01

  Right, right.

• 11:00Neil deGrasse Tyson?

  Ingredient.

• 11:01Speaker 01

  You don't want to send a whole thing of like sporks into space because that's the way to dispose of it.

• 11:06Neil deGrasse Tyson?

  And I don't know that sporks are destructible at all. Uh, but so you'd wanna not just scatter it into space. Space, we might want to travel that one day. So.

• 11:15Speaker 01

  Yeah, but we wouldn't put so much pollution into space that we'd be like, oh, we can't get to Mars.

• 11:19Neil deGrasse Tyson?

  I think they said that when they had built smokestacks. Oh, it's just a little bit of dirty air. Look how big the atmosphere is. Don't worry about it. Yeah.

• 11:28Speaker 01

  All right, all right. I won't throw, I won't throw my trash into space.

• 11:32Neil deGrasse Tyson?

  Let's have some foresight here. Next.

• 11:34Speaker 01

  George asks, uh, if we take an open jar into space, to outer space and close it, uh, once up, thereby filling it with the vacuum of space, what would happen if we bring it to, uh, to earth level atmosphere and even to the International Space Station?

• 11:50Neil deGrasse Tyson?

  It would be the best vacuum we would have ever encountered on earth ever.

• 11:53Speaker 01

  Really?

• 11:53Neil deGrasse Tyson?

  Yes. We can't make vacuums as good as space vacuums.

• 11:56Speaker 01

  Really?

• 11:57Neil deGrasse Tyson?

  Yeah. Last I checked, we can't do it.

• 12:00Neil deGrasse Tyson?

  Unless somebody last week pulled one off.

• 12:02Speaker 01

  We can't, uh, we can't, we can't, uh, have it as much as, space is just top notch.

• 12:07Neil deGrasse Tyson?

  Far better vacuum than anything we've been able to create in our laboratory.

• 12:10Speaker 01

  So why don't we always bring back jars of vacuum? I now have a new business where I'm gonna sell jars of the best vacuum you've ever seen.

• 12:18Neil deGrasse Tyson?

  But I like the way the question was worded, like that when the vacuum gets inside the jar, what happens is the air inside the jar escapes. Now, by the way, once you put the vacuum in it, and then you bring it back to earth, what will happen is the

• 12:29Speaker 01

  It'll explode or crush.

• 12:30Neil deGrasse Tyson?

  The inner surface of the glass and presumably a metal lid will outgas into that volume. Their gases dissolve on the surfaces of all solid objects. And it just stays there. It's molecules that are just stuck in the jaggedy surface of every of every solid object. If you now evacuate the center of that jar, it dislodges those gas molecules. And so it'll then put some kind of gas pressure back in. If you're ever trying to create a perfect vacuum, you first vacuum it out, then you heat the sides of the container, that releases the gas that's attached, then you vacuum it out again.

• 13:02Speaker 01

  So what would you bring into space to bring the vacuum back home?

• 13:04Neil deGrasse Tyson?

  Something that has a really, really smooth surface with hardly any gases attached to it.

• 13:09Speaker 01

  More, more smooth than glass?

• 13:11Neil deGrasse Tyson?

  Oh, yeah. Oh, yeah. So glass is, yeah, way more smooth. And you could preheat it before you did this. And

• 13:18Speaker 01

  You'd bring like Jon Hamm, just somebody who's super smooth. And be like, yeah, alright.

• 13:24Neil deGrasse Tyson?

  Oh, by the way, you might ask,

• 13:26Speaker 01

  Yeah.

• 13:26Neil deGrasse Tyson?

  if quote-unquote "nature abhors a vacuum," which of course it doesn't because most of the universe is vacuum. Um, how come all Earth's atmosphere doesn't just rush out into the vacuum of space?

• 13:34Speaker 01

  It's true.

• 13:35Neil deGrasse Tyson?

  You might ask. A vacuum on Earth,

• 13:37Speaker 01

  Mm-hmm.

• 13:38Neil deGrasse Tyson?

  We think of nature abhorring it because air wants to get inside the vacuum.

• 13:42Speaker 01

  Air wants to go into the vacuum.

• 13:43Neil deGrasse Tyson?

  Air wants to go in because you are in a place where there's air pressure that wants to get inside. As you get higher up in the atmosphere, the air pressure gets less and less and less and less and less. Because there's less air above it pressing down. And when you get less and less and less and less and less, the air doesn't want to do anything. It's got no forces, there's no air pressure to make it wa- it's just gonna float away. Okay, so our atmosphere goes out thousands of miles, getting ever so thinner as it gets out there. And so it's, it's not that Earth is holding the atmosphere down, although it is, because Earth has gravity and the gravity keeps the atmosphere separate from the rest of the vacuum of space. But the air pressure out there has no urge to go anywhere other than just staying right where it is.

• 14:25Speaker 01

  Right.

• 14:25Neil deGrasse Tyson?

  Yeah.

• 14:26Speaker 01

  Okay. So here's the question from Kyle.

• 14:31Neil deGrasse Tyson?

  Kyle.

• 14:32Speaker 01

  It is the same exact time everywhere in the universe. Like, I know you've talked about how the moon and space station is on Houston time because that's who they talk to, but is the whole of the universe within the same unit of time at the same time, or do the vast expansion of the universe do something funky with that?

• 14:50Neil deGrasse Tyson?

  Yeah, I mean, different parts of the universe are moving at different rates and time has some relative aspects to it. So, for example, the GPS satellites.

• 14:59Speaker 01

  Yeah.

• 15:00Neil deGrasse Tyson?

  The clocks on them tick at a different rate than clocks on Earth's surface. Because when you move far away from the gravity, from a source of gravity.

• 15:09Speaker 01

  Yeah.

• 15:09Neil deGrasse Tyson?

  Your time speeds up. So, the clocks on the GPS satellites are not ticking at the rate that of the clocks that they are informing down here on Earth. The military puts a correction into the clock time you get from a GPS satellite so that it matches the time we need it to have here on the Earth's surface. So, so if you're in motion, if you're near a gravity source or far from one, your clock is ticking at a slightly different time from everybody else's.

• 15:40Speaker 01

  Then what time is it on Jupiter?

• 15:43Neil deGrasse Tyson?

  Well, so, you go to Jupiter.

• 15:45Speaker 01

  Is it like 3:15?

• 15:46Neil deGrasse Tyson?

  No, you set up a time system. So, the way you want to answer that in an interesting way is you take two identical clocks, you put one on Earth and one on Jupiter, and watch what happens. The one on Jupiter will tick slower than the one on Earth.

• 15:58Speaker 01

  Really?

• 15:59Neil deGrasse Tyson?

  Because of Jupiter's gravitational field slows down the ticking of the clock.

• 16:04Speaker 01

  So, is, so one way to live forever is to go to Jupiter and sit there?

• 16:07Neil deGrasse Tyson?

  No, you'll just live longer than you would on Earth.

• 16:08Speaker 01

  Right, right, not forever, sorry, longer.

• 16:10Neil deGrasse Tyson?

  Yeah, you'll suffocate and, and die of pressure.

• 16:14Speaker 01

  You would bring a jar of air.

• 16:16Neil deGrasse Tyson?

  Ignoring that complication, yes, you can go to Jupiter and live slightly longer than you would here on Earth.

• 16:20Speaker 01

  How much longer, actually? Let's say your life is 100 years.

• 16:24Neil deGrasse Tyson?

  Oh.

• 16:24Speaker 01

  Like, minutes or years?

• 16:25Neil deGrasse Tyson?

  Yeah, no, minutes.

• 16:27Speaker 01

  Oh, oh, that's really not worth it. Sorry, I got excited. You're like, yeah, you'd live for 100 years and 10 minutes. Oh, that's super not worth it.

• 16:35Neil deGrasse Tyson?

  It's minute, I mean, off the top of my head, I think it's minutes, yeah.

• 16:39Speaker 01

  Yeah, yeah. All right, here's a question.

• 16:40Neil deGrasse Tyson?

  Yeah.

• 16:41Speaker 01

  I'm writing you from Kabul, Afghanistan, and my question is, we know the speed of light, do we know the speed of dark? And what is dark?

• 16:48Neil deGrasse Tyson?

  Oh, okay, so philosophers like.

• 16:50Speaker 01

  Signed, Batman.

• 16:51Neil deGrasse Tyson?

  Yep. Philosophers like asking questions such as that.

• 16:54Speaker 01

  Yeah.

• 16:55Neil deGrasse Tyson?

  The problem is if you align the verbs and nouns so that it makes something that sounds like a question, doesn't mean that it's an actual legitimate question. It's like saying, what flavor cheese is the moon made of?

• 17:06Speaker 01

  Right.

• 17:06Neil deGrasse Tyson?

  That's a que- it's a que- it's a lit- it's a literate question.

• 17:09Speaker 01

  Watch out, you're gonna spark a war in Afghanistan.

• 17:12Neil deGrasse Tyson?

  Just saying. So what is the speed of dark? If dark is the absence of light, dark has no speed at all.

• 17:17Speaker 01

  So there's an answer, it's zero.

• 17:19Neil deGrasse Tyson?

  Well.

• 17:19Speaker 01

  While the moon is not breed.

• 17:23Speaker 01

  So.

• 17:24Neil deGrasse Tyson?

  So just because we have a word for something that is the absence of light, doesn't mean the absence of light is a thing for you to then ask questions about.

• 17:32Speaker 01

  Right, right.

• 17:32Neil deGrasse Tyson?

  That's the point, physically. Like I said, philosophers go, you know, what is the sound of one hand clapping? You know.

• 17:37Speaker 01

  It depends if it's doing it well, it's still like this. I don't know if you can hear it, but that is literally one hand clapping, it's not so bad.

• 17:43Neil deGrasse Tyson?

  One hand clapping itself, yeah.

• 17:44Speaker 01

  Yeah.

• 17:44Neil deGrasse Tyson?

  So then that's the, that's the, um, the backdoor answer to that. So, so, uh, dark has no speed because it in fact does not exist as an entity. What we call dark is the absence of light.

• 17:55Speaker 01

  Yeah.

• 17:55Neil deGrasse Tyson?

  We are StarTalk Cosmic Queries Edition, we'll be right back.

• 18:17Neil deGrasse Tyson?

  StarTalk Radio Cosmic Queries Edition, Neil Tyson here, Eugene Mirman there. Eugene.

• 18:22Speaker 01

  Yes.

• 18:23Neil deGrasse Tyson?

  Comedian extraordinaire, always great to have you on StarTalk.

• 18:25Speaker 01

  Always wonderful to come.

• 18:27Neil deGrasse Tyson?

  We're, we're Cosmic Queries Edition, Grab Bag.

• 18:29Speaker 01

  Grab Bag, oh, you had more about darkness.

• 18:31Neil deGrasse Tyson?

  Oh, yeah, yeah, somebody asked from Kabul, Afghanistan.

• 18:34Speaker 01

  Yeah, what's the speed of dark?

• 18:35Neil deGrasse Tyson?

  The speed of dark, by the way, at night.

• 18:36Speaker 01

  Great metal band.

• 18:37Neil deGrasse Tyson?

  Uh, in Afghanistan, where there are very few city lights, at night it gets really dark, so.

• 18:42Speaker 01

  Yeah.

• 18:43Neil deGrasse Tyson?

  Interesting that someone from Afghanistan is asking about dark, and no one from New York City would ever ask about dark.

• 18:47Speaker 01

  Yeah, yeah.

• 18:48Neil deGrasse Tyson?

  Cause they don't experience the.

• 18:50Speaker 01

  There's no, there's no nighttime.

• 18:51Neil deGrasse Tyson?

  The dark. So there's an interesting question kids sometimes ask, you can pose the question, when you turn on the light, how do you know that light comes out of the bulb?

• 19:01Speaker 01

  Mm-hmm.

• 19:02Neil deGrasse Tyson?

  Rather than darkness leaves the room and enters the bulb.

• 19:05Speaker 01

  Yes.

• 19:06Neil deGrasse Tyson?

  Is there an experiment that you can conduct? And the answer is yes, you can put up a thing in the middle of the room and detect light hitting one side of that object and you will not detect anything else going back towards the light bulb. If dark was a thing that had speed, you'd be able to.

• 19:25Speaker 01

  You'd measure it.

• 19:26Neil deGrasse Tyson?

  You'd be able to measure it. Exactly. And this is the, this is the, one of the hallmarks of science that is underappreciated. In science, we measure stuff.

• 19:34Speaker 01

  Yeah.

• 19:34Neil deGrasse Tyson?

  And when you measure it, you can tag and bag it, you can.

• 19:38Speaker 01

  It's why you know that the universe is probably not 5,000 years old.

• 19:42Neil deGrasse Tyson?

  That's exactly.

• 19:43Speaker 01

  Can't prove it, but you've measured that it's unlikely.

• 19:46Neil deGrasse Tyson?

  What else you got?

• 19:47Speaker 01

  Uh, okay. From Norway. Let's suppose you.

• 19:51Neil deGrasse Tyson?

  I love these questions from.

• 19:53Speaker 01

  Yeah, I feel like, uh, we know that Europe and, uh, it listens. Okay, let's suppose you encounter an alien race. It looks like a three meter tall gummy bear. It has discernible anatomy parts, but you don't have any idea of what, uh, what does what. It makes sounds, but of course you don't understand anything. You are not sure that it has eyes. You are not sure it has ears. You're not sure if you touch it, he would, you are, you do know it's a guy though. You're like, definitely a guy. You, you're not sure if it would react, uh, overreact and, uh, disintegrate you with a phaser. Or if, uh, it would be just toxic and make you, uh, make you die instantly.

• 20:34Speaker 01

  But you know that it is very intelligent and he understand at least college. He understands at least college level mathematics, physics, chemistry, and in general has a good background in sciences. Uh, how would you proceed to communicate, uh, in order to communicate with it?

• 20:49Neil deGrasse Tyson?

  Yeah, okay.

• 20:50Speaker 01

  Uh, so what would you say if there's a, I see now that the question is, what would you do to a three meter tall gummy bear that's intelligent and studied our earth sciences?

• 20:59Neil deGrasse Tyson?

  Was it three meters tall?

• 21:01Speaker 01

  Three meters tall, yeah.

• 21:02Neil deGrasse Tyson?

  Three meters. So that's bigger than us, right? Yeah, tall human is two meters.

• 21:06Speaker 01

  Yeah. And he's like, if you touch it, it might hurt you, which you would instantly already assume.

• 21:10Neil deGrasse Tyson?

  Right. So, yeah, I wouldn't go for the. ...pluses, you know, if it extended something to shake your, you don't even know what part of its anatomy you're touching.

• 21:17Speaker 01

  Yeah, but it's a gummy bear, which actually is, he doesn't realize this is shaped like a bear.

• 21:21Neil deGrasse Tyson?

  It looks like a gummy bear, doesn't mean it is a gummy bear.

• 21:24Speaker 01

  But, but it does have legs, arms, a torso and a head.

• 21:27Neil deGrasse Tyson?

  I guess it would, but you don't know what the torso does versus the head. So you just don't go even go there. So what I would do is I would take the vocabulary of the universe. By the way, even if I didn't know that he got As in his astro, you know, physics.

• 21:38Speaker 01

  He didn't say he got As, he just said he had a pretty good student in my B pluses.

• 21:42Neil deGrasse Tyson?

  I would not have to know that he, this he gummy bear, took these classes. I wouldn't have to know that. I would know if he arrived here in a spaceship, the dude knows physics, okay? So I would set up certain physics demos.

• 21:56Speaker 01

  You can't imagine somebody would put a dummy into a spaceship, send them here and they'd be like, how'd you get here? And the dummy would be like, I don't. I have no idea. I really, I just walked into it as a bright light. All I have is this soup I brought from my world.

• 22:10Neil deGrasse Tyson?

  I mean, think about Tom Brokaw famously said, you know, was it Tom? I think it was Tom Brokaw. You know, I've been news anchor for thirty, my whole, my whole career and I still don't know how a TV works. And most people don't know how the stuff works. So it'd be unfortunate if they sent, you know.

• 22:24Speaker 01

  Someone who couldn't explain it.

• 22:26Neil deGrasse Tyson?

  Couldn't.

• 22:27Speaker 01

  Someone who was impressed by our old cathode ray tubes.

• 22:31Neil deGrasse Tyson?

  So, so if they got here, the dude knows, knows some physics, right? So I would take out simple physics experiment, like you know, the swinging ball experiment. I'd take some out, make sure they knew what that was and you'd start to build a science vocabulary. Cause that is the only thing that is not only international on earth, it is intergalactic.

• 22:48Speaker 01

  Right.

• 22:48Neil deGrasse Tyson?

  Right? Don't, don't start speaking French. You don't start asking Vatican.

• 22:53Speaker 01

  You start understanding science and math.

• 22:55Neil deGrasse Tyson?

  Understanding science.

• 22:56Speaker 01

  You start throwing up, you start, your first things are you throw up and loud sounds upset you.

• 23:00Neil deGrasse Tyson?

  So I would, I would start building a vocabulary of scientific methods and tools. And that way we have a common place to start and then you increment your way from there. That's what anyone does even on a speed date.

• 23:11Speaker 01

  Right.

• 23:11Neil deGrasse Tyson?

  You start with what's in common.

• 23:12Speaker 01

  Science, where you do a science example on a speed date. Yeah. Um, all right, here's another question from Gwendolyn. Uh, Gwendolyn wants to know, is it possible to use quantum teleportation to explore inside a black hole? Since a teleported particle is not a light particle, it does not have to obey. Therefore, uh, would it be possible to send a particle into a black hole and get data from it?

• 23:35Neil deGrasse Tyson?

  Oh, uh, no, black holes don't distinguish matter from energy. You, you want to go into a black hole? Oh, well, so what's hap-

• 23:41Speaker 01

  What if you wore a helmet?

• 23:43Neil deGrasse Tyson?

  If you, so a black hole, you want to go in and then come back out again. Hawking radiation allows this. All the particles that enter a black hole will come out eventually as the black hole evaporates by way of Hawking radiation. So that's a really slow way to find out what the inside of the black hole was doing, but-

• 24:01Speaker 01

  Could you go into a black hole, wait 10,000 years and come out and be alive and fine?

• 24:04Neil deGrasse Tyson?

  No, because your particles will go in one by one and they'll come out one by one. You'll have to reassemble who and what you were, as well as your brain and your memory. We don't have that power yet.

• 24:11Speaker 01

  Not, yeah.

• 24:12Neil deGrasse Tyson?

  So, uh, just briefly, Hawking radiation is particles get spontaneously created in the gravity field outside the black hole. Uh, the particle pairs, one falls back in, the other escapes. All the particles that escape, it's the same inventory as the particles that it had eaten over its entire life. It's an awesome fact of the universe. You're listening to Cosmic Queries StarTalk. We'll be right back.

• 24:51Neil deGrasse Tyson?

  We're back, StarTalk Radio. These questions came from the internet, starTalkRadio.net, from Twitter, StarTalk Radio, from Google Plus.

• 25:01Speaker 01

  Yeah.

• 25:01Neil deGrasse Tyson?

  Yeah.

• 25:01Speaker 01

  Some of these emailed?

• 25:02Neil deGrasse Tyson?

  Facebook, so give them to me.

• 25:03Speaker 01

  This one's from Australia.

• 25:05Neil deGrasse Tyson?

  And I haven't seen any of them.

• 25:06Speaker 01

  No. This one's from Australia, from Dave Willis.

• 25:08Neil deGrasse Tyson?

  So if I don't have an answer, I'll-

• 25:09Speaker 01

  Yeah. Not the one who created Aqua Teen Hunger Force. Uh, so anyway, here's a question from Australia. Would you be able to explain the differences between black holes, supermassive black holes, quasars, and white holes? I'm very interested in this subject, but any information I find is vague and sometimes- Contradicts previous info.

• 25:28Neil deGrasse Tyson?

  In the 1970s, the black hole formula that told us what a black hole is and how it works, it was discovered had a second solution to it.

• 25:35Speaker 01

  Mm hmm.

• 25:36Neil deGrasse Tyson?

  And the second solution was the mathematical opposite of the solution that described a black hole. So a black hole, nothing comes out, anything always goes in.

• 25:43Speaker 01

  Mm hmm.

• 25:44Neil deGrasse Tyson?

  The white hole, everything only ever comes out.

• 25:46Speaker 01

  Oh.

• 25:47Neil deGrasse Tyson?

  And so people wondered, could a black hole be connected to a white hole?

• 25:52Speaker 01

  Yeah.

• 25:52Neil deGrasse Tyson?

  Through a wormhole in the fabric of space.

• 25:54Speaker 01

  I think you're describing zebras now.

• 25:56Neil deGrasse Tyson?

  So anything that goes into a black hole would then come out a white hole. And if that were the case, a white hole would be a highly radiant thing.

• 26:03Speaker 01

  Yeah.

• 26:03Neil deGrasse Tyson?

  And if it is, what are these radiant things at the edge of the universe? They're quasars. Could a white hole be a quasar?

• 26:09Speaker 01

  Mm hmm.

• 26:10Neil deGrasse Tyson?

  So we made them, we mapped out what a white hole should look like. We looked at what quasars look and they don't match at all.

• 26:15Speaker 01

  No.

• 26:15Neil deGrasse Tyson?

  So we have no evidence for white holes.

• 26:16Speaker 01

  So white holes might not exist.

• 26:18Neil deGrasse Tyson?

  They likely don't exist.

• 26:19Speaker 01

  And if they do, they're full of stuff that would be awesome to have.

• 26:22Neil deGrasse Tyson?

  That would be so awesome. It'd be energy.

• 26:24Speaker 01

  That's just pouring out of nowhere.

• 26:25Neil deGrasse Tyson?

  Pouring out of nowhere, exactly.

• 26:27Speaker 01

  That would be fun.

• 26:28Neil deGrasse Tyson?

  Uh, so quasars, our current model for quasars, which is stable and we all sort of agree what's going on here, is that there is a black hole in the center of a galaxy.

• 26:35Speaker 01

  Mm hmm.

• 26:36Neil deGrasse Tyson?

  And it is dining upon material that comes too close. And the act of dining upon it swirling down toilet bowl style heats up the stars, the gas and everything else, and it radiates profusely. That is what we call a quasar phenomenon. And quasar stands for quasi stellar radio source. It's a loose acronym.

• 26:55Speaker 01

  Oh.

• 26:55Neil deGrasse Tyson?

  For that, because the energy is coming from such a tiny spot on the sky, because it's with the volume of a black hole in the center of a galaxy. It, it, it's, it's, they call it quasi stellar because stars are points of light. These are points of light.

• 27:07Speaker 01

  Mm hmm.

• 27:08Neil deGrasse Tyson?

  Even though they have nothing to do with stars themselves, they're super massive black holes dining upon matter that came too close. And then you have black holes, white holes, white holes, quasars.

• 27:17Speaker 01

  All right. So here's a question.

• 27:20Neil deGrasse Tyson?

  Yeah.

• 27:20Speaker 01

  It's from Jay. With enough resources and energy, would we be able to move the sun? And if so, would we come along for the ride?

• 27:32Neil deGrasse Tyson?

  This is how diabolical evil people are.

• 27:35Speaker 01

  Yeah, this is how like he's like, I'm building a machine. I don't think I have enough copper for it.

• 27:41Neil deGrasse Tyson?

  All right.

• 27:42Speaker 01

  So yeah, and would we go along with it if we did?

• 27:45Neil deGrasse Tyson?

  I would just wonder why one would want to do this. Uh, but if you move the sun.

• 27:49Speaker 01

  Yeah.

• 27:50Neil deGrasse Tyson?

  Uh, that would be hard. Uh, yes, the planets would come along, but you would disturb their orbits briefly. They would resettle, but in a slightly disturbed way. So in other words, we're orbiting where the sun is right now. Now you move the sun.

• 28:04Speaker 01

  Yeah.

• 28:05Neil deGrasse Tyson?

  We still orbit where the sun was for eight minutes and 20 seconds. Cause that's how long it takes gravity to reach us. Then we figure out, oh, the sun is now in a different place.

• 28:12Speaker 01

  Yeah.

• 28:13Neil deGrasse Tyson?

  Our orbit no longer applies to the sun in the new place.

• 28:17Speaker 01

  So the earth starts moving.

• 28:18Neil deGrasse Tyson?

  So then we say, well, we got to find a new orbit that works. All the planets have to find new orbits. If you're going to start accelerating the sun. The fact is the sun is already moving in orbit around the galaxy with all the planets and comets and moons and Pluto in tow. So we are already a moving system. And in fact, if you plotted this through space, the sun would make a sort of a straight line and all the planets would stay around the sun as they move forward. And you get this helical, beautifully artistic spirals.

• 28:47Speaker 01

  The sun is already moving. We don't need to push it.

• 28:49Neil deGrasse Tyson?

  You don't push it.

• 28:50Speaker 01

  How much energy would it take to push the sun?

• 28:52Neil deGrasse Tyson?

  Uh.

• 28:53Speaker 01

  Without blowing it up, I wouldn't want to put in the sun's worth of energy into it.

• 28:56Neil deGrasse Tyson?

  Sun is four times 10 to the 33 grams. So you do the math.

• 29:02Speaker 01

  So four to the 34 grams, would that be enough, Neil?

• 29:08Neil deGrasse Tyson?

  No, you have to find out how to do, you can't push a gas. So you have to figure out how to do this.

• 29:12Speaker 01

  You'd need a giant hand.

• 29:14Neil deGrasse Tyson?

  Yeah.

• 29:14Speaker 01

  All right, this sounds complicated.

• 29:16Neil deGrasse Tyson?

  All right, one minute left in this segment.

• 29:18Speaker 01

  Okay, here's a question from Michael. If hot air rises, why is the temperature at the height that airplanes fly so cold?

• 29:26Neil deGrasse Tyson?

  Ooh.

• 29:27Speaker 01

  Solid question.

• 29:28Neil deGrasse Tyson?

  Nice.

• 29:29Speaker 01

  Michael Burns.

• 29:29Neil deGrasse Tyson?

  Nice question. Well, the sun doesn't heat the air, the sun heats the ground.

• 29:34Speaker 01

  Uh huh.

• 29:34Neil deGrasse Tyson?

  Basically, that's how that works. And so, and there's a little time delay. The heat on the ground then heats the air, and that's why the hottest time of day is not 12 noon. It's a couple hours later.

• 29:43Speaker 01

  Hmm.

• 29:44Neil deGrasse Tyson?

  It takes time for the ground.

• 29:45Speaker 01

  3:30.

• 29:45Neil deGrasse Tyson?

  Yeah, it can be as late as in Texas, uh, 4 o'clock, depending on where you are in the time zone. And so that can happen. Also, uh, it delays the hottest month of the year from what otherwise being June to being July and August. June has the most direct sunlight on the first day of summer.

• 30:02Speaker 01

  Yeah.

• 30:03Neil deGrasse Tyson?

  But, uh, otherwise it's delayed. So, uh, so these are the effects of what happens when the sun is heating the earth.

• 30:11Speaker 01

  Hot air doesn't rise enough.

• 30:12Neil deGrasse Tyson?

  Well, I think when we come back, you'll find out why it's cold in airplanes. StarTalk Cosmic Queries Edition.

• 30:38Neil deGrasse Tyson?

  We're back in the last segment of Cosmic Queries StarTalk Grab Bag Edition. We left off, someone asked a great question, how come it's cooler up in the sky, up in the atmosphere where airplanes fly if hot air rises?

• 30:49Speaker 01

  Yeah.

• 30:50Neil deGrasse Tyson?

  The reason why hot air rises is because it's less dense than the air around it. That's the only reason why it rises. So as it rises, it is looking for air that has the same density as it.

• 31:02Speaker 01

  Mm hmm. And where does it find it?

• 31:04Neil deGrasse Tyson?

  And where does it find it? It could find it at any cut, at any altitude, but while that's happening, that pocket of air is expanding and cooling.

• 31:12Speaker 01

  Ah.

• 31:13Neil deGrasse Tyson?

  So there's no such thing as a free lunch here. And this hot air does expand, does rise up, and that's gives you thunderheads.

• 31:19Speaker 01

  Right.

• 31:19Neil deGrasse Tyson?

  Thunder clouds or hot unstable air. And you look at the clouds in stop action, you see the top of the cloud roiling as it rises. rises up and if this happens in a big way you get cumulonimbus clouds and rainstorms and even hail so but it'll reach the point where it's equal and that point is not as high as where planes fly

• 31:35Speaker 01

  like planes fly higher

• 31:37Neil deGrasse Tyson?

  we are in the

• 31:38Speaker 01

  lightning round

• 31:39Neil deGrasse Tyson?

  lightning round Eugene I take too long to answer all the other questions we're gonna blow through this list

• 31:43Speaker 01

  yeah

• 31:43Neil deGrasse Tyson?

  okay go

• 31:44Speaker 01

  this is easy question if the multiverse theory is true is it possible to travel to other universes? how would it be possible for us to exist in those universes if they have different laws of physics?

• 31:53Neil deGrasse Tyson?

  okay it may be possible to travel to another universe but I would not be the volunteer to do so if it has different laws of physics you're you could end up in a pile of goo because the forces that guide and control your molecules and atoms if they're different you don't want to be the first one to go

• 32:07Speaker 01

  so you'd go the second

• 32:09Neil deGrasse Tyson?

  even even if you could go to that universe send somebody else

• 32:13Speaker 01

  great are there any plasma rockets that are close to being ready to go to Mars what is the timeframe how do they work?

• 32:19Neil deGrasse Tyson?

  yeah

• 32:20Speaker 01

  this is like is it true tell me how to build one

• 32:23Neil deGrasse Tyson?

  so that's my lightning round question

• 32:25Speaker 01

  yeah

• 32:25Neil deGrasse Tyson?

  yes we do have plasma rockets they're ion drives and they are not good for sort of launching things they're good for slowly changing the direction and they're good for very long trips

• 32:36Speaker 01

  yeah

• 32:36Neil deGrasse Tyson?

  or if you're gonna send cargo to Mars and you don't you can take you know years to get it there you know a high shelf life product go ahead but if you're gonna move people the ion drive is not a good option for people at this point

• 32:48Speaker 01

  would you ever

• 32:48Neil deGrasse Tyson?

  it takes too slow to move you

• 32:49Speaker 01

  would you okay you would use it on earth?

• 32:51Neil deGrasse Tyson?

  no no no no next good

• 32:53Speaker 01

  great uh if we could manage to build a spaceship that could accelerate at a constant one G could we leverage time dilation to reach the nearest galaxy within the lifetime of a human on the spaceship?

• 33:03Neil deGrasse Tyson?

  uh the nearest galaxy no but you can definitely uh if you could accelerate at one G and that way you can walk around in the spaceship as though you're on earth because you'd have a one G acceleration that would be cool

• 33:14Speaker 01

  yeah

• 33:14Neil deGrasse Tyson?

  no bone marrow no no bone mass loss or anything all these problems you hear about of being in zero G uh we can go ahead and do that uh go to the nearest stars and come back and yes time dilation you'll eventually reach near the speed of light time dilation will allow you to not age very much but people on earth will continue to age and when you come back everyone will have forgotten about you next

• 33:35Speaker 01

  okay it's my understanding that Black hole will just vanish and disappear and at the end of its life. If that is so and equals mc squared, what happens to the energy of all the particles the black hole has consumed?

• 33:46Neil deGrasse Tyson?

  Ooh, so there's no such thing as a free lunch. So all the energy of the stuff that fell in, in Hawking radiation, it all comes back out again and you leave nothing left behind.

• 33:55Speaker 01

  Great.

• 33:56Neil deGrasse Tyson?

  Uh, not even the smile of the black hole. Next.

• 33:59Speaker 01

  Okay, a galaxy.

• 34:00Neil deGrasse Tyson?

  Next.

• 34:00Speaker 01

  A galaxy several hu- several hundred thousand, uh, thousands of light years across. How do we know what a galaxy actually looks like if we are not seeing the same time from the galaxy, from the entire galaxy?

• 34:11Neil deGrasse Tyson?

  Oh, great point. So the point is, if our galaxy is a hundred thousand light years across.

• 34:16Speaker 01

  Yep.

• 34:16Neil deGrasse Tyson?

  And you're on one edge, you don't see the whole galaxy at once. You see the nearby stuff as it was yesterday. The stuff farther away as it was a week ago.

• 34:22Speaker 01

  Yeah.

• 34:23Neil deGrasse Tyson?

  The stuff, uh, at the other edge of the galaxy as it was a hundred thousand light years, a hundred thousand years ago. You're not seeing the whole thing at once. So the best way to do it is to come above it. And then every, all the light comes to you at once.

• 34:33Speaker 01

  Okay.

• 34:33Neil deGrasse Tyson?

  And we have galaxies out there that are face on to us. We see them all at once.

• 34:37Speaker 01

  And that's.

• 34:37Neil deGrasse Tyson?

  The galaxy is not doing nasty things over the hundred thousand years that that takes. Galaxy live for billions of years. It's not going to do anything really drastic in a hundred thousand years. Next.

• 34:47Speaker 01

  Uh, what will, uh, building the square kilo, uh.

• 34:52Neil deGrasse Tyson?

  Collider?

• 34:53Speaker 01

  Yeah.

• 34:53Neil deGrasse Tyson?

  Uh huh.

• 34:53Speaker 01

  Allow, uh, us to see in space?

• 34:55Neil deGrasse Tyson?

  Oh, so what you want is huge, huge telescopes to make big buckets to see, get more light of any kind, radio waves, microwaves, x-rays. The one, in, in astrophysics, bigger is better.

• 35:09Speaker 01

  Mm hmm.

• 35:09Neil deGrasse Tyson?

  Period.

• 35:10Speaker 01

  Yes.

• 35:10Neil deGrasse Tyson?

  So, um, the square kilometer ray sees, it sees radio waves and, and, and microwaves. And you will look into the universe, seeing things dimmer than you could have ever seen before. Because this will be the bigger telescope than we've ever made before.

• 35:24Speaker 01

  So what we'll see is a lot more.

• 35:25Neil deGrasse Tyson?

  What?

• 35:26Speaker 01

  Is what you're saying.

• 35:28Neil deGrasse Tyson?

  Because you can see things that are bright or you can see dim things that you would never, would, would not have even otherwise shown up.

• 35:34Speaker 01

  Right.

• 35:34Neil deGrasse Tyson?

  Right? And so that's where.

• 35:35Speaker 01

  We'll be able to use it to see the movie Grown Ups 2.

• 35:39Neil deGrasse Tyson?

  So you see it to see stuff you could not have seen before. One more.

• 35:43Speaker 01

  Okay, excluding size and distance from the sun, does Venus have more in common with the gas giants than the terrestrial planet?

• 35:51Neil deGrasse Tyson?

  Venus is like our twin. It is about the same size, the same gravity, nearly the same composition, except that it's 900 degrees Fahrenheit and we are not. It has a runaway greenhouse effect. Carbon dioxide atmosphere that is nearly 100 times the pressure of what you have here on Earth. If you go there, you will die. But it is otherwise a twin to Earth, appropriately called Earth Twin, a sister planet. There you have it. We gotta go.

• 36:14Speaker 01

  We gotta go.

• 36:15Neil deGrasse Tyson?

  Eugene.

• 36:16Speaker 01

  Bye.

• 36:16Neil deGrasse Tyson?

  Thanks again for being here.

• 36:17Speaker 01

  Great to be here.

• 36:18Neil deGrasse Tyson?

  Star Talk.

• 36:18Speaker 01

  Yes.

• 36:19Neil deGrasse Tyson?

  Cosmic Queries Edition.

• 36:20Speaker 01

  All right.

• 36:21Neil deGrasse Tyson?

  Grab Bag. I'm Neil deGrasse Tyson, your personal astrophysicist. As always, I bid you farewell, which means I say to you, to keep looking.