Cosmic Queries: A Powerful Potpourri

Neil deGrasse Tyson and Chuck Nice tackle an eclectic mix of your questions that take us from the boiling surface of the Sun to the dark side of the moon and Earth’s distant past to the last moments of the universe.

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. My day job, I'm the director of the Hayden Planetarium at the American Museum of Natural History, right here in New York City. This is the Cosmic Queries edition, which I do not do alone. I need help. I've got Chuck Nice.

• 0:41Chuck Nice?

  Hey Neil.

• 0:42Neil deGrasse Tyson?

  Chuck Nice, comic, right here with me in studio.

• 0:45Chuck Nice?

  That's right.

• 0:46Neil deGrasse Tyson?

  Calling from the internet, questions, this is not a themed Cosmic Queries.

• 0:49Chuck Nice?

  This is our potpourri!

• 0:51Neil deGrasse Tyson?

  Potpourri, I don't even know how to spell that.

• 0:52Chuck Nice?

  A veritable grab bag.

• 0:55Neil deGrasse Tyson?

  Grab bag, a smelly grab, potpourri is smells, right?

• 0:58Chuck Nice?

  Yes, yes.

• 0:59Neil deGrasse Tyson?

  So this is whatever was left over in the bag after we pulled out the questions.

• 1:03Chuck Nice?

  A smelly grab bag of StarTalk radio.

• 1:06Neil deGrasse Tyson?

  It could be themed. Let's get right into it.

• 1:09Chuck Nice?

  Yeah, man.

• 1:10Neil deGrasse Tyson?

  I haven't seen these questions, so if I don't know something, I'm gonna tell you.

• 1:12Chuck Nice?

  There you go, and guess what? That's one of the best things, is that you're kinda shooting from the hip on this one, but you never really shoot from the hip, you know? Cause you know what you're talking about. So here we go, this is from Harry Dasori, alright? Subject matter? Dark matter.

• 1:29Neil deGrasse Tyson?

  Dark matter, sure.

• 1:30Chuck Nice?

  Alright, get ready for this one.

• 1:32Neil deGrasse Tyson?

  By the way, there was a chapter of my memoir called Dark Matters.

• 1:36Chuck Nice?

  Yes, there's a chapter of my life called Dark Matters.

• 1:39Neil deGrasse Tyson?

  I'm just saying, we each have some dark matters.

• 1:42Chuck Nice?

  Everybody's got some dark matters going on. Alright, here we go. Let me finish before you freak out, okay? "I've witnessed ghosts and several experiences that have made me a believer in the supernatural, or what some would call spiritual existence."

• 1:59Neil deGrasse Tyson?

  Who's question?

• 2:00Chuck Nice?

  This is from Harry Dasori.

• 2:01Neil deGrasse Tyson?

  Okay.

• 2:02Chuck Nice?

  "My question to you Neil is, can the expansion of dark matter in the universe be the accumulation of souls of all the planets in the cosmos? Some speculate that soul has weight, or a value of weight."

• 2:19Chuck Nice?

  Impossible to prove.

• 2:22Neil deGrasse Tyson?

  Okay, well, so where shall we begin?

• 2:25Chuck Nice?

  Yes, I don't know.

• 2:26Neil deGrasse Tyson?

  He wants to connect his personal experiences with ghosts.

• 2:29Chuck Nice?

  Yes.

• 2:29Neil deGrasse Tyson?

  With the dark matter in the universe.

• 2:31Chuck Nice?

  Right, so what he's saying is these apparitions that he has experienced.

• 2:34Neil deGrasse Tyson?

  Mm-hmm.

• 2:35Chuck Nice?

  Clearly, they must have some type of mass or weight. Could dark matter actually be the accumulation of all such apparitions as the ones that he's experienced?

• 2:45Neil deGrasse Tyson?

  All the souls, okay.

• 2:46Chuck Nice?

  All the souls.

• 2:47Neil deGrasse Tyson?

  So, a couple of things, let's tackle souls for the moment, alright? Uh, back when X-rays were invented, were discovered by Wilhelm Röntgen, who's a German physicist. He, in fact, he won the first Nobel Prize in Physics in 1900 for his discovery of X-rays. Uh, people, soulful people of the day said, if X-rays can see through matter and through the human body, maybe if we X-rayed a body that was dying, we'd be able to see the soul leave the body.

• 3:17Chuck Nice?

  What?

• 3:18Neil deGrasse Tyson?

  I don't know. There you go, and so, they attempted these experiments and nothing, they didn't see nothing.

• 3:25Chuck Nice?

  Right, thank God the person was already dying.

• 3:30Chuck Nice?

  Exposing them to all those X-rays like that.

• 3:32Neil deGrasse Tyson?

  And in a rare moment, we're thanking God for someone dying, right? Alright, so, so first there was that, alright. Second, the instant you die, which is, has a fuzzy, we don't really. I tweeted recently, uh, the next person who, who is brought back to life after being pronounced clinically dead. It seems like we need to start redefining what dead is. If you keep coming back because you were clinically dead.

• 4:00Chuck Nice?

  Right.

• 4:01Neil deGrasse Tyson?

  Maybe clinically dead really isn't dead, alright?

• 4:03Chuck Nice?

  True.

• 4:04Neil deGrasse Tyson?

  Right, so, uh, the point is, there was some movie called Twenty Three, whatever, remember this movie?

• 4:09Chuck Nice?

  Yes, I know what you're talking about, Twenty Three Ounces or some crazy.

• 4:12Neil deGrasse Tyson?

  Yeah, Twenty Three Grams, Twenty One.

• 4:14Chuck Nice?

  Twenty One Grams.

• 4:14Neil deGrasse Tyson?

  Twenty One Grams, right, it's just BS. If you, if, if you're alive and then you're dead and you're on a scale, your weight doesn't change, alright? Unless you evacuate your bowels and it spills off the scale onto the floor.

• 4:27Chuck Nice?

  Right.

• 4:27Neil deGrasse Tyson?

  Okay, plus, most people don't know how much Twenty One Grams actually is. Do you know how much that, it's like the weight of a nickel, I mean, it's not very much.

• 4:34Chuck Nice?

  No, it's not a lot at all.

• 4:35Neil deGrasse Tyson?

  It's not a lot at all, so.

• 4:37Chuck Nice?

  I know because of my past use of cocaine.

• 4:43Neil deGrasse Tyson?

  Because drug dealers were metric long before any American got involved. How many grams?

• 4:49Chuck Nice?

  Whenever I meet somebody who knows the metric system, I'm like, you've done a lot of drugs, haven't you? Or sold them.

• 4:56Neil deGrasse Tyson?

  So, uh, the point is when you die, you have way more than that of just leftover, leftover urine and bowel contents. So, uh, and your, your sphincters relax and it all comes out of you, right? But if you're not careful about how you make those measurements, you could be led to think that you weigh less at death than you did alive. But so anyhow, so if it's soul in terms of the mass of the soul, if you want to believe there is one, there's no evidence that it has mass.

• 5:25Chuck Nice?

  Right.

• 5:25Neil deGrasse Tyson?

  Second, we know approximately how many people there have been ever born. It's about a hundred billion plus or minus.

• 5:31Chuck Nice?

  Okay.

• 5:31Neil deGrasse Tyson?

  So, uh, a hundred billion times any number is really, no matter what number you're multiplying it by, it's going to be small compared with the mass equivalent of the dark matter of the universe. Now, he's saying the souls of all the planets. So he's going to have to believe that there's life on other planets.

• 5:48Chuck Nice?

  Correct.

• 5:49Neil deGrasse Tyson?

  That has souls.

• 5:50Chuck Nice?

  Correct.

• 5:50Neil deGrasse Tyson?

  And so it's the sum of all the souls. And I'm just, there's no evidence for that. Now, one of the things science does that nothing before science did was establish something that is objectively true. So if I say, I saw it, it's real. Well, was it in your head or was it actually real?

• 6:08Chuck Nice?

  Right. What are the qualifiers of seeing?

• 6:10Neil deGrasse Tyson?

  Exactly. Science allows us to distinguish something that's happening in your head from something that is objectively true, that everybody can agree with as well as apparatus that we have built to make the measurement.

• 6:21Chuck Nice?

  Correct.

• 6:22Neil deGrasse Tyson?

  So what he needs to do is find the ghosts, grab, you know, put them in a net or something, bring them to the lab or, or get more than himself as witness to these ghosts.

• 6:33Chuck Nice?

  Correct.

• 6:33Neil deGrasse Tyson?

  Then we can start making measurements. Until then, we kind of have to sort of, I'm going, I'm left saying that it's all going on in his head and therefore we don't have to explain cosmic forces that affect the, the birth of the universe based on what he sees out of his own head.

• 6:47Chuck Nice?

  Right. So basically, uh, in the corporeal world, Harry, you are out of your mind.

• 6:57Neil deGrasse Tyson?

  No, in other words, that's just to be fair to his question. He may have surely been seeing ghosts.

• 7:02Chuck Nice?

  Right.

• 7:03Neil deGrasse Tyson?

  That doesn't mean the ghosts are objectively real. That's all I'm saying.

• 7:06Chuck Nice?

  Right, exactly.

• 7:07Neil deGrasse Tyson?

  The human mind is a complex place. We still don't understand.

• 7:09Chuck Nice?

  We still don't understand.

• 7:10Neil deGrasse Tyson?

  A whole new field called neuroscience has been born as we speak.

• 7:14Chuck Nice?

  To determine why we see these things.

• 7:15Neil deGrasse Tyson?

  To try to handle these things.

• 7:16Chuck Nice?

  Right, right.

• 7:17Neil deGrasse Tyson?

  So, I'm not saying he's not telling the truth about what he believes he saw.

• 7:21Chuck Nice?

  Exactly.

• 7:21Neil deGrasse Tyson?

  But whether it's an objectively true thing is a whole other thing.

• 7:25Chuck Nice?

  It could be true. It could just be his truth based upon his drinking of mushroom tea.

• 7:35Chuck Nice?

  The LSD is what made it true.

• 7:37Neil deGrasse Tyson?

  Or if he hasn't, and he does, that would take it a whole other notch.

• 7:40Chuck Nice?

  Exactly.

• 7:43Neil deGrasse Tyson?

  You're listening to the Cosmic Queries edition of StarTalk Radio. I'm here with Chuck Nice Comic tweeting at Chuck Nice Comic.

• 7:50Chuck Nice?

  That's correct, sir.

• 7:50Neil deGrasse Tyson?

  You got it. Uh, StarTalk Radio, we tweet as well at StarTalk Radio. And find us on the web, uh, starTalkRadio.net. We'll be back in a moment.

• 8:17Neil deGrasse Tyson?

  We're back, StarTalk Radio, Cosmic Queries edition. Chuck, you just reached to the bottom of the barrel and you just got whatever was left over. So, should we call this the potpourri?

• 8:27Chuck Nice?

  The potpourri.

• 8:28Neil deGrasse Tyson?

  Potpourri, alright, let's potpourri this.

• 8:29Chuck Nice?

  Or as you put it so eloquently, the smelly grab bag of StarTalk Radio.

• 8:34Neil deGrasse Tyson?

  What I think of potpourri is the stuff that smells nice and you put it in the bathroom where stuff otherwise doesn't smell nice.

• 8:39Chuck Nice?

  That's true, that's true.

• 8:40Neil deGrasse Tyson?

  You don't put potpourri in a rose garden.

• 8:42Chuck Nice?

  So true.

• 8:42Neil deGrasse Tyson?

  Right, so, okay.

• 8:43Chuck Nice?

  Now you sound like a philosopher, not, not an astrophysicist.

• 8:47Neil deGrasse Tyson?

  That is, you'd never put potpourri in a rose.

• 8:48Chuck Nice?

  No one puts potpourri in a rose garden.

• 8:51Neil deGrasse Tyson?

  Okay.

• 8:52Chuck Nice?

  Then I hear like Chinese chimes, you know what I mean? Just like, ah, snaster pepper from my hand, grasshopper. But, yeah, that's awesome.

• 8:59Neil deGrasse Tyson?

  Go.

• 9:00Chuck Nice?

  Alright, here we go, um... Adida, Adida Patil is uh.

• 9:05Neil deGrasse Tyson?

  I have to say you're the worst pronouncer of names I've ever had opposite me on a table.

• 9:08Chuck Nice?

  I am awful. I am, um, listen Neil, I am not going.

• 9:12Neil deGrasse Tyson?

  Somebody has to call your stuff out.

• 9:13Chuck Nice?

  Listen, I'm glad you're doing it, cause I am awful. I gotta admit, I'm terrible at this, alright? But uh, I, uh, I did ya, okay, whatever. Uh, Adida Patil says, by the way, she wants you to know that she is sixteen years old.

• 9:27Neil deGrasse Tyson?

  Mm-hmm.

• 9:28Chuck Nice?

  And she also wants you to know that she is from India, so we are worldwide buddy, we are worldwide.

• 9:33Neil deGrasse Tyson?

  There you go.

• 9:34Chuck Nice?

  Okay.

• 9:36Chuck Nice?

  Where does all the energy go when it's all over is her subject matter. You've said, Mr. Tyson, uh, Dr. Tyson, in many episodes, that the universe is going from chaos to order and would finally reach a state of zero Kelvin. My question is, where does all the energy go? All the kinetic energy that is present now, what happens to it?

• 9:57Neil deGrasse Tyson?

  Okay, I, I don't think I've ever said we're going from chaos to order. I don't, I don't think I've ever said that either.

• 10:03Chuck Nice?

  I think you've always said that the universe is in a state of, uh, extreme disorder.

• 10:07Neil deGrasse Tyson?

  Disorder and becoming more disorder, but she knows that we're temperatures dropping in the universe to, and approaching, uh, uh, there's a mathematical term for it asymptotically approaching absolute zero. When you're asymptote to something, it means you get ever closer to it, but will never actually reach it until you reach infinity.

• 10:26Chuck Nice?

  Kinda like fractals.

• 10:27Neil deGrasse Tyson?

  Uh, yeah, oh yeah, there's always detail all the way down through and it's never gonna stop.

• 10:31Chuck Nice?

  Never gonna stop.

• 10:32Neil deGrasse Tyson?

  Right, right. So, uh, so it's not exactly like fractals, but the idea that you're hitting some infinity point.

• 10:37Chuck Nice?

  Right.

• 10:37Neil deGrasse Tyson?

  And then it stops.

• 10:38Chuck Nice?

  Yeah, that's the only thing I could relate it to in my tiny little mind.

• 10:41Neil deGrasse Tyson?

  Alright, so, so you say where does the energy, the energy's still there, it's just more and more and more diluted, until it's so diluted that it, it's, it's effectively zero energy density in the universe.

• 10:52Chuck Nice?

  Okay.

• 10:53Neil deGrasse Tyson?

  So we're talking about energy density. Nor- normally we use the word density, we think of matter density, so, so lead is more dense than paper, right? And so it's, it, it makes good paperweights, although we don't use lead anymore, and nor do we even have paperweights. You know why we don't have paperweights?

• 11:08Chuck Nice?

  No.

• 11:09Neil deGrasse Tyson?

  Because we don't have fans inside of offices, because we have central air conditioning.

• 11:13Chuck Nice?

  Yes, which is exactly why the, uh, register above my desk keeps blowing the papers off my desk. Sorry.

• 11:22Neil deGrasse Tyson?

  Does it seriously? Well, whatever it is, it's less than what a fan would have done back in the day. So, so here we have the universe expands, temperature drops, atom totally approaches absolute zero. It's the density of the energy that continues to drop.

• 11:36Chuck Nice?

  So the energy doesn't go anywhere?

• 11:38Neil deGrasse Tyson?

  It's the total energy is the same.

• 11:39Chuck Nice?

  It's just diluted to the place where it is effectively zero energy.

• 11:44Neil deGrasse Tyson?

  It is so dilute, just go home.

• 11:48Neil deGrasse Tyson?

  So that's what's going on there.

• 11:49Chuck Nice?

  Yeah, that makes great sense.

• 11:50Neil deGrasse Tyson?

  And by the way, the opposite would be true. In a, in a, in a collapsing universe, the energy density would be going up. And the universe would be getting hotter and hotter and hotter over time.

• 11:57Chuck Nice?

  Okay.

• 11:58Neil deGrasse Tyson?

  Yeah, that'd be a bad.

• 11:58Chuck Nice?

  A bad thing, right?

• 12:00Neil deGrasse Tyson?

  Yeah, I'd rather end in ice than in fire.

• 12:04Chuck Nice?

  Okay, cool. Well, there you go. There you go. That's a great, great, great answer. Good question. All right, this is from Mark Fenimore, calls himself the chemistry nerd.

• 12:12Neil deGrasse Tyson?

  Ooh.

• 12:13Chuck Nice?

  Okay, here it is. Dr. Tyson, in a freshly brewed cup of coffee, if, I'm sorry, if a freshly brewed cup of coffee was placed into a pressurized, help me out here, adiabatic?

• 12:25Neil deGrasse Tyson?

  Adiabatic.

• 12:26Chuck Nice?

  Adiabatic? Adiabatic container and exposed to the vacuum of space while being shielded from the sun or starlight. How long would it take for said coffee to freeze? What is the mechanism for energy transfer in this case?

• 12:44Neil deGrasse Tyson?

  Well, if it's not, if it's not exposed to the outdoors.

• 12:47Chuck Nice?

  Right.

• 12:47Neil deGrasse Tyson?

  Uh, well, what you'd have to do is expand the volume. It's in a cavity and if you expand that cavity, the energy has to now dilute. And there'll be a point where it dilutes so low that you, then you freeze what's there. So, so that adiabatic is a, is a physics term, a chemistry physics term that refers to whether you keep pressure constant and change the temperature, or keep the temperature constant and change the pressure when you're doing these experiments. And so, uh, by the way, if you just had a canister there and if it was completely insulated, the temperature would never change.

• 13:19Chuck Nice?

  Right.

• 13:19Neil deGrasse Tyson?

  But it's, you cannot completely insulate something because there's always a molecule of something attached, connect, communicating with one adjacent to it. And either with, with light energy or with vibrational energy. So it's going to cool down no matter what.

• 13:33Chuck Nice?

  Okay, so the, the fact is that even if it were completely insulated, the fact is you can never completely insulate something.

• 13:42Chuck Nice?

  Is that what you're trying to tell me, Dr. Tyson?

• 13:47Neil deGrasse Tyson?

  So, yes, that, as well as if you want to sort of expand the volume, because there'll be pressure in there because it's a warm cup of coffee. If you try to expand the volume, what will ultimately happen is the energy density will drop.

• 13:59Chuck Nice?

  And then at some point, it will actually freeze.

• 14:02Neil deGrasse Tyson?

  Yeah, if you keep doing that, yeah.

• 14:03Chuck Nice?

  Right.

• 14:04Neil deGrasse Tyson?

  Yeah, you can drop it so low, but maybe you'd have to evaporate all of the coffee before that happened, and then it's gaseous, and then the concept of freezing no longer matters. So, as material changes state, it's a fascinating thing, actually.

• 14:17Chuck Nice?

  Yeah.

• 14:18Neil deGrasse Tyson?

  That we don't spend enough time on in school, I think. Now, just think about it. Here's this water, and then you drop the temperature, then it becomes solid.

• 14:24Chuck Nice?

  Right.

• 14:25Neil deGrasse Tyson?

  A liquid becomes... Imagine if you had never seen ice. Just ima... I mean, there were people who grew up in the tropics.

• 14:31Chuck Nice?

  And never saw ice.

• 14:33Neil deGrasse Tyson?

  In their life.

• 14:33Chuck Nice?

  That's right.

• 14:34Neil deGrasse Tyson?

  And then you just take water, put it in some vest, some cavity, and you pull it out, and it's solid. They're not even gonna believe you.

• 14:39Chuck Nice?

  He has magic!

• 14:43Neil deGrasse Tyson?

  If physicists never told people how we do stuff, we would just be... People, we would be the gods of our culture.

• 14:51Chuck Nice?

  True.

• 14:51Neil deGrasse Tyson?

  Because we would have powers that they would... that they think would divine.

• 14:55Chuck Nice?

  Exactly. You know what? It's so funny, as a quick aside, there is a great show for kids, and it's really trippy, but it's called Adventure Time, and there's a character, she's a scientist, and she is constantly railing against the people of the kingdom because they believe in magic.

• 15:12Chuck Nice?

  It's awesome. That's great. All right, there you go. Let's move on to Jeremy Zucaro. Okay, I got that one right. Jeremy Zucaro.

• 15:22Neil deGrasse Tyson?

  You could at least try to put a little... Jeremy Zucaro.

• 15:24Chuck Nice?

  Zucaro.

• 15:25Neil deGrasse Tyson?

  Yeah, there.

• 15:25Chuck Nice?

  Zucaro. Okay, there we go.

• 15:27Neil deGrasse Tyson?

  The most interesting man in the world.

• 15:29Chuck Nice?

  Jeremy Zucaro.

• 15:30Neil deGrasse Tyson?

  Go.

• 15:31Chuck Nice?

  Okay, "Could intelligent life have evolved on Earth in the distant past? There seems to be little evidence to support this idea, but would there be? But would there be? What are the odds that this would be missed in fossil evidence? And is there a physical reason why this could not have happened?"

• 15:51Neil deGrasse Tyson?

  I think about this all the time.

• 15:52Chuck Nice?

  Do you really?

• 15:53Neil deGrasse Tyson?

  Yes.

• 15:53Chuck Nice?

  Okay, cool.

• 15:54Neil deGrasse Tyson?

  I lay awake at night, I lay awake at night, thinking about this question.

• 15:58Chuck Nice?

  Okay, cool.

• 15:58Neil deGrasse Tyson?

  Because I... What I do is I ask, if civilization ended today, how long would it take, given the... Earthquakes and volcanoes and other, other geologic forces on earth. How long would it take for every trace of our civilization?

• 16:14Chuck Nice?

  To be just gone.

• 16:15Neil deGrasse Tyson?

  Completely gone, of being sucked into the magma of a volcano and coming out as a fresh rock.

• 16:20Chuck Nice?

  Right.

• 16:20Neil deGrasse Tyson?

  All right, some jump starting the, the geologic record. And I've spoken with some geologists about this. It would, it would be billions of years. It's not.

• 16:29Chuck Nice?

  Oh, okay.

• 16:30Neil deGrasse Tyson?

  Yeah, it's, it's a while because you have to get every bit, we're everywhere on earth, not basically. You have to get every bit of landmass, deep enough down so that it's completely, completely wiped out.

• 16:41Chuck Nice?

  Right.

• 16:41Neil deGrasse Tyson?

  And, and, and melted down and reshaped into the next.

• 16:44Chuck Nice?

  Because the earth is literally remaking itself.

• 16:47Neil deGrasse Tyson?

  It is rep.

• 16:48Chuck Nice?

  Over time, right?

• 16:49Neil deGrasse Tyson?

  Yes, it is. And it has to be sort of uniform enough so that there's no trace. So I said, could there have been an intelligent civilization in the past? And I think not, uh, for, for not, I think not. First, because it would take a long time to completely wipe them off the map. Second, uh, complex life is a, is an evolutionary trajectory.

• 17:11Chuck Nice?

  Gotcha.

• 17:11Neil deGrasse Tyson?

  You would not have had single-celled life forms, three billion years ago, popping into a multicellular intelligent life form.

• 17:19Chuck Nice?

  Right.

• 17:19Neil deGrasse Tyson?

  Overnight.

• 17:20Chuck Nice?

  Right.

• 17:20Neil deGrasse Tyson?

  Making a civilization then disappearing again. You, you have to track it through the growth of complexity in the evolutionary chain. And when you do that, you only get sort of big-brained if intelligence derives from big brain. You only start getting big-brained mammals after the dinosaurs are taken out of the picture.

• 17:37Chuck Nice?

  Gotcha.

• 17:38Neil deGrasse Tyson?

  And that was 65 million years ago.

• 17:40Chuck Nice?

  Right.

• 17:40Neil deGrasse Tyson?

  Our mammal ancestors scurrying underfoot, trying to not be hors d'oeuvres for T-Rex. Only when T-Rex got taken away, did our mammal brain start getting big and become anything that we call intelligence today.

• 17:51Chuck Nice?

  Gotcha. So now, what's, when you look at that trajectory, uh, is what you're saying, that the earth has not been here long enough for that trajectory to have taken place in the past and then been wiped away record-wise, so that we are finding ourself in that place again today.

• 18:07Neil deGrasse Tyson?

  It's a combination of not only that, you would not expect complex neurological organ, organisms, organisms with. Neurology to have been around long enough ago, given the time it would have taken to create such a creature.

• 18:22Chuck Nice?

  Gotcha.

• 18:22Neil deGrasse Tyson?

  As the evidence of the fossil record shows.

• 18:24Chuck Nice?

  Fantastic.

• 18:25Neil deGrasse Tyson?

  So there you have it.

• 18:25Chuck Nice?

  There you go, man. That's a great answer.

• 18:27Neil deGrasse Tyson?

  When we come back, more of Cosmic Queries Potpourri Edition. You're listening to StarTalk.

• 18:50Neil deGrasse Tyson?

  We're back on StarTalk, Cosmic Queries Edition Potpourri.

• 18:56Neil deGrasse Tyson?

  Chuck, what? You're the one who dug dug all these questions out of the bottom of the barrel because they didn't fit any other category.

• 19:05Neil deGrasse Tyson?

  I, I, there's a question about whether there's past life on Earth. I want to add something to that.

• 19:08Chuck Nice?

  Go ahead.

• 19:09Neil deGrasse Tyson?

  There's a lot of science fiction storytelling that has sort of aliens helping out our civilization.

• 19:13Chuck Nice?

  Yes.

• 19:14Neil deGrasse Tyson?

  You know, like Stargate, for example.

• 19:16Chuck Nice?

  Stargate.

• 19:16Neil deGrasse Tyson?

  You know, the pyramids came from some.

• 19:19Chuck Nice?

  Well, aliens who came down, helped us build it and then left.

• 19:21Neil deGrasse Tyson?

  And then.

• 19:22Chuck Nice?

  For some strange reason, just like, hey, we need to go build some pyramids on Earth.

• 19:26Neil deGrasse Tyson?

  On Earth.

• 19:27Chuck Nice?

  In that spot. In that spot, and then we're out of here.

• 19:32Chuck Nice?

  That's their sole purpose of coming here. These humans look like they need pyramids.

• 19:36Neil deGrasse Tyson?

  Yeah, and they're not mechanical or anything. They're just stone.

• 19:39Chuck Nice?

  Just stone buildings that we are going to, because we're that technologically advanced. Let's give these people some stone triangles to drop in the middle of a desert and then we're out of here.

• 19:49Neil deGrasse Tyson?

  Okay. Yeah, so that, that I couldn't, that's what I was gonna say. No, so the urge to think that ancient peoples could not have actually done these great uh, structures, I mean, the fact is they have the same brain that we do.

• 20:02Chuck Nice?

  We do.

• 20:03Neil deGrasse Tyson?

  Right, and so they have less technology, but they're not any less smart.

• 20:06Chuck Nice?

  Right.

• 20:06Neil deGrasse Tyson?

  In fact, some could argue that they're smarter.

• 20:08Chuck Nice?

  Absolutely.

• 20:08Neil deGrasse Tyson?

  So I'm always upset when we want to credit some intelligent aliens for stuff that our own species did here on Earth.

• 20:15Chuck Nice?

  Exactly.

• 20:15Neil deGrasse Tyson?

  Give us some credit, man.

• 20:16Chuck Nice?

  It's funny because, you know, my son, who's seven years old.

• 20:19Neil deGrasse Tyson?

  Mm-hmm.

• 20:20Chuck Nice?

  And he said, well, how come, you know, if they didn't have anything technical back in the day, they could actually create these great buildings and things, but yet we don't seem to be as smart as they are? And I went, because they didn't have cable television, son.

• 20:35Neil deGrasse Tyson?

  Exactly.

• 20:36Chuck Nice?

  That's why.

• 20:37Neil deGrasse Tyson?

  And they had a hundred years to build it.

• 20:38Chuck Nice?

  Right, exactly.

• 20:41Neil deGrasse Tyson?

  It's none of this, oh, look, we gotta, we gotta get this done by October.

• 20:44Chuck Nice?

  Right.

• 20:44Neil deGrasse Tyson?

  No, no, pyramids is like, take it, whatever, however long it takes.

• 20:47Chuck Nice?

  Right, lifetimes and nobody cared.

• 20:48Neil deGrasse Tyson?

  Right.

• 20:49Chuck Nice?

  Right, we got numbered out. That's great.

• 20:51Neil deGrasse Tyson?

  All right, well, she got.

• 20:52Chuck Nice?

  Here we go. Um, this is from our very own, uh, somebody here in New York City and, uh, Andrew Wood. Andrew Wood.

• 20:59Neil deGrasse Tyson?

  And you pronounce his name correctly.

• 21:00Chuck Nice?

  Yes, I did. Thank you, Andrew, for having a very easily, easy to pronounce name.

• 21:05Neil deGrasse Tyson?

  All right.

• 21:05Chuck Nice?

  All right. We have several impact craters on Earth from meteorites. My question is this. We have, we have the big holes, but where did the big freaking rock disappear to?

• 21:19Neil deGrasse Tyson?

  Ooh.

• 21:19Chuck Nice?

  I will not be able to sleep until I know.

• 21:21Neil deGrasse Tyson?

  Oh, I like people who can't sleep because science keeps them awake. That is good. So a couple of things, probably the most famous hole in the ground is, is in, uh, meteor hole in the ground is in Arizona.

• 21:32Chuck Nice?

  Right.

• 21:33Neil deGrasse Tyson?

  Near Winslow, Arizona. In fact, I was just there filming for Cosmos.

• 21:36Chuck Nice?

  Oh, cool.

• 21:37Neil deGrasse Tyson?

  Yeah, cool. Okay, you can't not go to the.

• 21:39Chuck Nice?

  Well, you have to.

• 21:39Neil deGrasse Tyson?

  Crater. It's almost a mile across and you can.

• 21:42Chuck Nice?

  Now, now, is this the crater that they say may have wiped out everything? Is this the?

• 21:45Neil deGrasse Tyson?

  No, no, no, no, no, no. This one, it was a bad day in Arizona when this thing hit.

• 21:48Chuck Nice?

  Okay.

• 21:49Neil deGrasse Tyson?

  Or whatever it was called back then, 50,000 years ago. There's, then there's another crater that was found submerged under the Gulf. Uh, found primarily by the efforts of oil drillers trying to find out the gravity anomalies. Cause you, if it's oil or is it sand, is it sediment? And they found this ridge and this ridge is the rim of a crater. And that's the one we traced.

• 22:11Chuck Nice?

  Okay.

• 22:12Neil deGrasse Tyson?

  To the dead dinosaurs.

• 22:13Chuck Nice?

  Gotcha.

• 22:13Neil deGrasse Tyson?

  And that hit near, in the Yucatan Peninsula, near what is now Mexico. And I once gave a talk and I said, uh, but I, I said, near what is now Mexico? I said, but that's not what the dinosaurs called it. And someone in the front row said, yeah, they called it Mexico.

• 22:32Chuck Nice?

  That's actually funny.

• 22:33Neil deGrasse Tyson?

  Spanish fluent dinosaurs. So, yes, we do have these craters in the Chesapeake Bay area. We now know from space is a meteor impact. So meteor impact created Chesapeake Bay.

• 22:43Chuck Nice?

  Look at that.

• 22:43Neil deGrasse Tyson?

  Yeah, right there in Maryland.

• 22:44Chuck Nice?

  Alright.

• 22:45Neil deGrasse Tyson?

  So, so there you have it. So what happened to the rock?

• 22:47Chuck Nice?

  What happened to the rock?

• 22:49Neil deGrasse Tyson?

  That if the speed of the asteroid, which is true in every case, is higher, so you have a speed and you can calculate how much energy it has for motion. We call it kinetic energy. Kinetic is motion. So write down that number. Okay, you can calculate that.

• 23:05Chuck Nice?

  Right.

• 23:05Neil deGrasse Tyson?

  Now you say, what's this thing made of? Is it rock? Is it metal? What's holding it together? Is, are there bonds? There are chemical bonds from one atom to another. There's a crystal lattice. There's some forces holding the thing together.

• 23:21Chuck Nice?

  Right.

• 23:21Neil deGrasse Tyson?

  Right. Add that up. Write down that number. If the kinetic energy number is bigger than the number that's holding it together, poof, and the thing hits, where did all the kinetic energy go? Back into the object and it explodes, vaporizes, goes to smithereens. And so, in fact, most of it essentially vaporizes.

• 23:42Chuck Nice?

  Gotcha.

• 23:43Neil deGrasse Tyson?

  And that's called a high-speed collision. And that's what happens. That's why you have fragments scattered, but the most, the bulk mass of the asteroid is gone. Now, if the thing came in slowly, it would just hit and bounce and then you could get the whole...

• 23:56Chuck Nice?

  And the rock would be sitting around?

• 23:58Neil deGrasse Tyson?

  In fact, meteor crater was purchased by a, by a, by a metal speculator because he presumed that the huge object that made the crater is still buried beneath.

• 24:11Chuck Nice?

  Still there.

• 24:12Neil deGrasse Tyson?

  Yeah. So we had metal, he bought the land, brought out his metal detectors, drilled bore holes, didn't find a damn thing.

• 24:18Chuck Nice?

  Oh.

• 24:19Neil deGrasse Tyson?

  Yeah, poor guy.

• 24:20Chuck Nice?

  Because he didn't have your, your formula. All he needed was your formula. It would've saved him a lot of money. Now this dude is just like every dude you see with black socks and sandals on the beach.

• 24:32Neil deGrasse Tyson?

  With his little, with his little metal detector. So it's the, it's, it's the Behringer family and they actually still own the land. And so now it's a tourist attraction and they're making money. Money off a tourist.

• 24:41Chuck Nice?

  Okay, well, at least he got his money back somehow.

• 24:43Neil deGrasse Tyson?

  Some somehow.

• 24:44Chuck Nice?

  Mm hmm.

• 24:45Neil deGrasse Tyson?

  So, uh, yeah, so that's what happens in a, in a high speed impact. And if it's, if those two numbers were different, the object would basically stay in one piece.

• 24:52Chuck Nice?

  Right. So there's your answer, uh, Mr. Wood. Uh, look for the rock in the land of smithereens.

• 24:59Neil deGrasse Tyson?

  Exactly. You're listening to StarTalk Radio, Cosmic Queries, Popery Edition. We'll be right back.

• 25:24Neil deGrasse Tyson?

  We're back. StarTalk Cosmic Queries, Popery Edition. Chuck Nice.

• 25:29Chuck Nice?

  Hey.

• 25:30Neil deGrasse Tyson?

  You're reading me these questions? I haven't seen or heard any of them.

• 25:32Chuck Nice?

  That's right. That's right. You have not seen them or heard them, but I have them right here.

• 25:36Neil deGrasse Tyson?

  Go for it.

• 25:37Chuck Nice?

  Okay, let's go to, uh, John. I'm. Right ska. Right ska. Okay, you know, it's John. I hope. I'm sorry, John. So.

• 25:49Chuck Nice?

  Okay, uh, subject of the tides, and this is kind of something that we've touched on.

• 25:53Neil deGrasse Tyson?

  Oh, me and tides go way back.

• 25:54Chuck Nice?

  Yeah, you and tides.

• 25:55Neil deGrasse Tyson?

  Oh, me, just back up.

• 25:56Chuck Nice?

  You are the veritable prince of tides. See what I did there? Did you see what I did there? Okay.

• 26:01Neil deGrasse Tyson?

  I thought I was the king of tides, but okay, fine.

• 26:04Chuck Nice?

  Okay, uh, I've heard Neil mention in multiple episodes that the gravitational forces of both the moon and the sun combine during a full moon to create the highest tides on Earth. It seems to me that they should cancel each other out, being that the masses are on opposite sides of the Earth. It also seems that the highest tide should be during the new moon because the moon and the sun are both on the same side of the Earth.

• 26:32Chuck Nice?

  I could look up the answer, but I just love hearing Chuck Nice's take on the questions.

• 26:38Neil deGrasse Tyson?

  Did he really say that?

• 26:39Chuck Nice?

  He did really say that.

• 26:40Neil deGrasse Tyson?

  Oh, my God.

• 26:43Chuck Nice?

  Alright, so listen, basically what he's saying is, uh, when the moon and the sun are on the same side, is there a greater pull?

• 26:52Neil deGrasse Tyson?

  So, so here we go, you ready?

• 26:53Chuck Nice?

  Go ahead, please.

• 26:54Neil deGrasse Tyson?

  Alright, so let's forget the sun for the moment.

• 26:57Chuck Nice?

  Alright.

• 26:57Neil deGrasse Tyson?

  We'll just have earth and the moon. The moon raises tides on earth.

• 27:02Chuck Nice?

  Gotcha.

• 27:02Neil deGrasse Tyson?

  And there are only two things that affect that. The mass of the moon, which isn't changing.

• 27:06Chuck Nice?

  Right.

• 27:07Neil deGrasse Tyson?

  And the distance the moon is from earth.

• 27:09Chuck Nice?

  Right.

• 27:10Neil deGrasse Tyson?

  Those are the only two things that can affect the tides that the moon raises on earth.

• 27:14Chuck Nice?

  Okay.

• 27:15Neil deGrasse Tyson?

  Now, the moon's orbit is not an exact circle. It's like a flattened circle, an ellipse is the official term. Think of it as an oval. And so occasionally the moon is closer to the earth, it'll raise slightly higher tides. Occasionally the moon is farther, raise slightly lower tides. And that has nothing to do with what phase the moon is. The moon's tides on earth are the same for every phase, from new moon, crescent, first quarter, gibbous, everybody...

• 27:38Chuck Nice?

  Because the moon is the same size.

• 27:40Neil deGrasse Tyson?

  Moon is the same damn thing in the damn sky.

• 27:42Chuck Nice?

  Right, right.

• 27:43Neil deGrasse Tyson?

  Alright, so now, now, bring in the sun.

• 27:47Chuck Nice?

  Okay.

• 27:47Neil deGrasse Tyson?

  The sun is trying to raise tides too. And it's a function of how far are we from the sun and how much mass the sun is. It's trying to do this on us too. But it turns out its strength of tides is only about a third as strong as that of the moon, turns out. Because it's so far away.

• 28:01Chuck Nice?

  So far away.

• 28:02Neil deGrasse Tyson?

  Distance makes a big deal with, it makes a big difference with tides.

• 28:05Chuck Nice?

  Gotcha.

• 28:05Neil deGrasse Tyson?

  Because the tidal strength varies as the cube of the distance.

• 28:09Chuck Nice?

  Gotcha.

• 28:10Neil deGrasse Tyson?

  If you're math fluent, you got that.

• 28:12Chuck Nice?

  I know what you're saying.

• 28:13Neil deGrasse Tyson?

  Alright.

• 28:13Chuck Nice?

  So it is directly and proportionally tied to the distance?

• 28:17Neil deGrasse Tyson?

  Yes.

• 28:18Chuck Nice?

  Okay.

• 28:18Neil deGrasse Tyson?

  To the third power of the distance.

• 28:19Chuck Nice?

  Third power, right.

• 28:20Neil deGrasse Tyson?

  So if you're far away, it's way less than if you're nearby.

• 28:22Chuck Nice?

  Gotcha.

• 28:23Neil deGrasse Tyson?

  So now watch. If the moon's tides align with the sun's tides, you have high tide. Higher than at any other time.

• 28:31Chuck Nice?

  Gotcha.

• 28:31Neil deGrasse Tyson?

  If the moon's tide is at right angles to the sun's tides, they're each trying to bulge at right angles to one another. They, that's where they cancel out.

• 28:43Chuck Nice?

  Gotcha.

• 28:43Neil deGrasse Tyson?

  Okay? That, at right angles, and I think call it the neap tide, alright? You'll still get a slightly high tide, but it's not as high as at full moon or at new moon. And here's how the tide works, you ready? Okay. So, you have the moon and you have earth.

• 28:57Chuck Nice?

  Mm-hmm.

• 28:57Neil deGrasse Tyson?

  The moon is pulling harder on the side of the earth closer to the moon than it is at the middle of the earth. And it is pulling harder at the middle of the earth than it is pulling at the far side of the earth.

• 29:09Chuck Nice?

  Right.

• 29:10Neil deGrasse Tyson?

  Because it's farther away.

• 29:11Chuck Nice?

  It's farther away. Because it's like we said, it's distance.

• 29:14Neil deGrasse Tyson?

  It's a distance.

• 29:15Chuck Nice?

  It's a distance thing.

• 29:16Neil deGrasse Tyson?

  Thank you. And so now you are a squishy pool of water. The side of you closest to the moon is being pulled most. And the side of you farthest from the moon is being pulled least. So all this gets stretched out. That's all it is. It's a big stretching game.

• 29:32Chuck Nice?

  Gotcha.

• 29:33Neil deGrasse Tyson?

  By the way, the solid earth has tides as well. But you know, it, we don't, that doesn't manifest as, because it's, it's a solid thing that's changing. But we see, and tides are, never come in and out. The bulge is always there in space and it's earth turning inside the bulge. So in fact, when you-

• 29:51Chuck Nice?

  That sounds so dirty. Oh my god.

• 29:54Neil deGrasse Tyson?

  So when you, if you're on the beach, you say, here comes the tide. No, the tide was there in space and you are on earth being turned into it.

• 30:02Chuck Nice?

  Turned into it.

• 30:03Neil deGrasse Tyson?

  Into the bulge of the tide.

• 30:04Chuck Nice?

  Wow.

• 30:05Neil deGrasse Tyson?

  I know, I know, I know. So now watch. So now, so the, the, the moon stretches out the water, near side, far side. The sun stretches out the water, near side, far side. So a new moon or a full moon, everybody's lined up, everybody's stretching it out. There you have it. It's all just stretching.

• 30:21Chuck Nice?

  It's all just, it's basically a love triangle between the sun, the moon, and the water.

• 30:29Neil deGrasse Tyson?

  However, when the triangle is at its finest, it makes a straight line.

• 30:35Chuck Nice?

  Ah.

• 30:36Neil deGrasse Tyson?

  Yeah, that's where you want your highest triangle.

• 30:37Chuck Nice?

  That's the highest triangle.

• 30:38Neil deGrasse Tyson?

  I mean, the highest bolt is the straight line triangle. That's right.

• 30:42Chuck Nice?

  Yo, that's hot.

• 30:43Neil deGrasse Tyson?

  You, you got it. You're still listening to StarTalk Radio Cosmic Queries. I'm here with Chuck Nice, we'll be right back.

• 31:09Neil deGrasse Tyson?

  We're back. StarTalk Cosmic Queries, Copery Edition. But we're in the final segment, which means what?

• 31:15Chuck Nice?

  Lightning round!

• 31:17Neil deGrasse Tyson?

  Lightning round, because I take so long answering the questions that we gotta pile them all, the ones I didn't get to in the last segment, and I'll blow through them soundbite style.

• 31:26Chuck Nice?

  Okay.

• 31:26Neil deGrasse Tyson?

  All right, are you ready? Let's do it.

• 31:28Chuck Nice?

  And that's the sound you'll hear at the end of the question.

• 31:30Neil deGrasse Tyson?

  No, at the end of my answer.

• 31:32Chuck Nice?

  End of the answer.

• 31:33Neil deGrasse Tyson?

  Go.

• 31:33Chuck Nice?

  "Amputees in space" from Jeff Lowe wants to know, "Hey, just curious to hear your thoughts about whether amputees in space would do well, since there's less muscles to atrophy. I'm also curious to hear if there would be effects from 0G on organs." You know, after all, the heart is a muscle, but it's constantly working, even in space.

• 31:50Neil deGrasse Tyson?

  Yeah, so amputees in space, you're not walking anywhere. So, in fact, the space walk, you're not walking, it's called space floating.

• 31:58Chuck Nice?

  It's space floating.

• 31:58Neil deGrasse Tyson?

  So, in a way, you don't really need your legs. So, amputees, I think, would do very well spacewalking. Your organs are sort of suspended in your body. They're not loose to float around and get out of alignment if you go into 0G. Plus, when you lay down horizontally, your heart does not work against gravity. It pumps blood horizontally, and that's like it not working against gravity. So, your heart would be just fine in space.

• 32:22Chuck Nice?

  Okay.

• 32:23Neil deGrasse Tyson?

  But it was not obvious. In the early days, we didn't know whether you could swallow in space. Does your saliva know to go down your throat? Turns out, the body does a good job pushing liquids wherever they gotta go. Next.

• 32:36Neil deGrasse Tyson?

  Go.

• 32:37Chuck Nice?

  Here's one. How about Adam Caspi? "You're a biggest fan in Israel." That's what he said.

• 32:42Neil deGrasse Tyson?

  Okay.

• 32:43Chuck Nice?

  "From my limited understanding, nothing can travel above the speed of light. Why does light travel at exactly that speed? I understand that it can't travel faster, but why not slower? Even a small amount, like 2 meters per second."

• 32:58Neil deGrasse Tyson?

  Light does travel slower when it goes through anything other than a vacuum.

• 33:02Chuck Nice?

  Ooh, ooh, ooh, oh, snap!

• 33:05Chuck Nice?

  Yo, Adam!

• 33:07Neil deGrasse Tyson?

  Light goes slower when it enters our atmosphere, which is why when you see sunrise, it's not actually risen yet. It is still below the horizon. Because when it changes medium, this light slows down and it refracts, showing you the sun before it has actually risen. Light is at its slowest through diamond. It only goes 40% as fast as its speed in a vacuum through diamond. That's why there's all this internal reflection in your ring, and it looks radiant, because the light internally reflected multiple times before it came out, looking like the diamond itself is giving you light. Oh, thank you.

• 33:42Chuck Nice?

  Well, there you go. Yo, that was, that was hot. That was hot.

• 33:45Neil deGrasse Tyson?

  Yeah.

• 33:45Chuck Nice?

  All right, here we go. Uh, this one from Luke Schlonigan.

• 33:48Neil deGrasse Tyson?

  Luke, yes, go. Luke.

• 33:50Chuck Nice?

  Aliens. On your aliens episode, you said aliens the size of a solar system couldn't exist because it would take too long for a signal to travel from one point of the brain to another, and for the alien to react. But what if it did not have a centralized brain? What if the decision-making capabilities were spread throughout? In other words, couple little brains around that alien head?

• 34:13Neil deGrasse Tyson?

  No, I, okay, I didn't say life could not exist. I just thought it would be really clumsy form of life.

• 34:19Chuck Nice?

  Got you.

• 34:19Neil deGrasse Tyson?

  If it stubs its toe, its toe, it would take 10 hours to respond to that fact. Or if it's, if something starts eating it, it won't know until it's way too late. It's just not an effective size to be life. If you're competing against the, the speed of light for you to communicate signals across your body. If it has regionally controlled centers, brain centers?

• 34:39Chuck Nice?

  Right.

• 34:39Neil deGrasse Tyson?

  Then is it one organism?

• 34:42Chuck Nice?

  Ooh, snap!

• 34:45Neil deGrasse Tyson?

  There you go.

• 34:46Chuck Nice?

  Oh.

• 34:46Neil deGrasse Tyson?

  I question whether it is in fact one organism. Luke, there's your answer. Okay.

• 34:52Chuck Nice?

  All right.

• 34:52Neil deGrasse Tyson?

  Next.

• 34:53Chuck Nice?

  Cody in Iowa wants to know, in an extremely unlikely scenario, if you were to be touching or right next to a micro black hole at the moment of its formation, what would happen?

• 35:06Neil deGrasse Tyson?

  Bad for you, good for the black hole. Yeah. If any part of you starts to enter the black hole, the black hole will just eat whatever part of you it touches. That, that's all she, eventually, you are gone.

• 35:18Chuck Nice?

  You're gone.

• 35:18Neil deGrasse Tyson?

  And the black hole burps. No, doesn't even burp.

• 35:23Neil deGrasse Tyson?

  Yeah, black hole one, human zero.

• 35:25Chuck Nice?

  There you go. All right, Cody, you are delicious to black holes. All right, this from Matt Hoesley. The sun. How loud would the sun be from the earth if there was a way to transmit the sound through space? I don't know what the hell that means. So I couldn't read the question.

• 35:44Neil deGrasse Tyson?

  Okay, so if you ever heard a pot of water boiling on the stove?

• 35:48Chuck Nice?

  Yes, I have.

• 35:48Neil deGrasse Tyson?

  Okay, that's water and it's, okay, the sun is boiling as well.

• 35:52Chuck Nice?

  Okay.

• 35:52Neil deGrasse Tyson?

  It's roiling, boiling, convecting. Convection is the scientific word for boiling.

• 35:57Chuck Nice?

  Right.

• 35:57Neil deGrasse Tyson?

  The sun is boiling like it's nobody's business on its surface. It would be the loudest boiling pot of water you ever heard. If somehow you can, you can, you can deliver that sound through the vacuum of space to us. And that'd be kind of cool to listen to what the sun was doing. It would sound like boiling oatmeal.

• 36:14Chuck Nice?

  Boiling oatmeal.

• 36:15Neil deGrasse Tyson?

  But really, really loud.

• 36:19Chuck Nice?

  Answer, thank God we can't hear that.

• 36:22Neil deGrasse Tyson?

  Real quick, 10 seconds.

• 36:23Chuck Nice?

  Okay, we've got 10 seconds and, oh my God, here it is. If there were a civilization that lived only on the far side of the moon, how hard would it be for it to detect the existence of the earth?

• 36:33Neil deGrasse Tyson?

  Oh, they would, they would never see earth because earth is never in their sky. But they would know somebody was up to something because we've sent spacecraft in orbit around the moon. And the most famous photo ever, Earthrise, was a spaceship coming around the backside of the moon. They would have said, uh-oh, we are not alone in the universe.

• 36:51Chuck Nice?

  Sweet.

• 36:51Neil deGrasse Tyson?

  So would the far side moon dwellers say? You've been listening to StarTalk Cosmic Queries. Chuck, thanks for being on.

• 36:58Chuck Nice?

  Always a pleasure.

• 36:59Neil deGrasse Tyson?

  We brought you in part by a grant from the National Science Foundation. I'm Neil deGrasse Tyson, your personal astrophysic, as always, bidding you to keep looking up.