Cosmic Queries – Galactic Grab Bag – Blue Steel

Terraforming mars? How do black holes die? On this episode, Neil deGrasse Tyson and comic co-host Chuck Nice answer questions about the moon, periodic table of elements, light photons, black holes and more!

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.

• 0:14Neil deGrasse Tyson?

  This is StarTalk Cosmic Queries Edition. I got Chuck Nice, my co-host Chuck.

• 0:20Chuck Nice?

  Hey Neil, what's happening?

• 0:22Neil deGrasse Tyson?

  Chuck, this is Grab Bag.

• 0:24Chuck Nice?

  It is indeed. We used to call it the Cosmic Potpourri. We used to call it Cosmic Gumbo, which was my favorite. Galactic, not Cosmic.

• 0:35Neil deGrasse Tyson?

  Galactic Gumbo.

• 0:36Chuck Nice?

  Galactic Gumbo.

• 0:37Neil deGrasse Tyson?

  Got to get that alliteration.

• 0:39Chuck Nice?

  And, uh, but now we have a Grab Bag, which it makes me wonder, where does that come from? Grab Bag, you know it means just like an assortment of pretty much miscellaneous items.

• 0:50Neil deGrasse Tyson?

  Yeah, yes, the presence in the holiday season where you reach in and grab and you don't know what you're getting.

• 0:55Chuck Nice?

  Is that really what it is?

• 0:56Neil deGrasse Tyson?

  From Santa Claus, why wouldn't it be?

• 0:58Chuck Nice?

  Okay, cool.

• 0:59Neil deGrasse Tyson?

  Yeah.

• 0:59Chuck Nice?

  Yeah, we called that Christmas.

• 1:04Neil deGrasse Tyson?

  You've been in my office, I have a Grab Bag in there that's a black hole.

• 1:07Chuck Nice?

  Right.

• 1:08Neil deGrasse Tyson?

  And it says black hole on the side of it.

• 1:10Chuck Nice?

  Right, it is.

• 1:11Neil deGrasse Tyson?

  It says black hole. That's how you know it's a black hole, it says it.

• 1:15Chuck Nice?

  Very nice, very cool.

• 1:17Neil deGrasse Tyson?

  That reminds me of, completely off topic, but the discoverer of Pluto. His name is Clyde Tombaugh. My boy lived into his, deep into his 90s. And, because he wasn't letting go of Pluto any sooner than he had to.

• 1:29Chuck Nice?

  He was hoping that, he was hoping that it would happen.

• 1:32Neil deGrasse Tyson?

  He was, he was trying to keep it.

• 1:34Chuck Nice?

  Yeah, on his deathbed, they told him, "You did it, it's a planet." And he was just like, "Oh, thank God."

• 1:42Chuck Nice?

  And, "Why'd you lie to him? He's died, he's dead! He's dead! What do you mean, why did I lie to him? That's like somebody's dying and you say to them, "You know I never loved you."

• 1:54Neil deGrasse Tyson?

  Long time to report that information.

• 1:56Chuck Nice?

  Exactly, it's like, "He's dead, like, let him, you know, I loved you so dearly my entire life, I so miss you." And then they die and you're like, "Oh, thank God."

• 2:06Neil deGrasse Tyson?

  So, he, so, he was asked, "How did you, how, what did it take to discover Pluto? You know, how hard was that?" And he said, "Well, when I got the photos of the nice guy, it was really easy because there was an arrow pointing to it."

• 2:20Chuck Nice?

  Oh, that's hilarious.

• 2:23Neil deGrasse Tyson?

  Every picture you've ever seen of Pluto.

• 2:24Chuck Nice?

  There is an hour. That's funny.

• 2:28Neil deGrasse Tyson?

  So, there you go. All right, so let's do this. Grab that.

• 2:31Chuck Nice?

  Okay, yeah, that's right.

• 2:32Neil deGrasse Tyson?

  Anything under the sun and above it as well.

• 2:34Chuck Nice?

  There you go.

• 2:34Neil deGrasse Tyson?

  So, let's go for it.

• 2:35Chuck Nice?

  Okay, now that makes me think the first question.

• 2:38Neil deGrasse Tyson?

  Well, just to remind people, these are all from Patreon.

• 2:40Chuck Nice?

  Yes.

• 2:41Neil deGrasse Tyson?

  Members, yeah.

• 2:41Chuck Nice?

  And if you, if you would like, please go to patreon.com/startalkradio, support us. And our, our.

• 2:50Neil deGrasse Tyson?

  Entry level.

• 2:50Chuck Nice?

  Our entry level, thank you Neil, our entry level, um, members. Uh, you get to ask Neil a question on our, and the reason we did that one is because Patreon is a great way for us to experiment and try things because you're supporting us financially. But more importantly, we were getting like fifteen thousand people asking questions. And so this is a great way to cull it down. So, we're not asking you to pay for your questions, but in return for your gracious support, you know, we ask questions.

• 3:23Neil deGrasse Tyson?

  Which sounds like they're paying for the question.

• 3:24Chuck Nice?

  All right. And I knew you were gonna do that.

• 3:27Neil deGrasse Tyson?

  No.

• 3:27Chuck Nice?

  I tried to NPR this, Neil. I tried to NPR this.

• 3:31Neil deGrasse Tyson?

  You were, you were smelling NPR the whole way.

• 3:34Chuck Nice?

  Okay. You pulled a chuck on me. You were like, yeah, and we are paying for it.

• 3:43Neil deGrasse Tyson?

  I shouldn't hang around you for so long.

• 3:45Chuck Nice?

  Oh, my God. All right, here we go.

• 3:47Neil deGrasse Tyson?

  Give it to me.

• 3:48Chuck Nice?

  This is David Brian Smith, and he says,

• 3:54Chuck Nice?

  uh, yes, this is really my name, not just made up. So, actually, you can pronounce it, Chuck. Oh, you jerk. I should read these in advance.

• 4:04Chuck Nice?

  All right, David, you got me. Um, he says, uh, can you explain the moon's wobble and how it affects the Earth? Interesting. Okay.

• 4:20Neil deGrasse Tyson?

  Well, so, I don't think he's referring to the moon's wobble, because that's not interesting. What's interesting, there's something called a libration. Not libation, not libation, don't confuse it.

• 4:33Chuck Nice?

  Is it anything like a liger?

• 4:36Neil deGrasse Tyson?

  No. Okay. A libration. A libration, right. You mean ligre, like the cross between a lion and a tiger? Yeah, you ever see those things? They're huge. Yeah, yeah, no, that's not, this has nothing to do with that, Chuck. Oh, I just heard lie. Okay, a libration. So what's happening is, the moon's orbit, again, I'm assuming that's what he's referring to, because the moon doesn't have a wobble that anyone cares about, so that's why. But there's an interesting libration. So what's happening is, because the moon's orbit around the Earth is not a perfect circle, okay, it's an ellipse. It can get as close as 225,000 or so miles, and as far as almost 250,000 miles.

• 5:21Neil deGrasse Tyson?

  So there's a 25,000 mile range between when it's closest and when it's farthest. Okay. The moon is also tidally locked to Earth, so it's always showing the same face. Okay? That's a natural phenomenon in the universe. And systems of orbiting objects naturally descend into that state relative to each other. So that's fine. No, nothing weird going on there. Here's the problem. Okay? If it were a perfectly circular orbit, you would only ever see exactly the same side, and it's locked, you'd only ever see exactly the same side towards you. Okay. Here's the problem.

• 6:02Neil deGrasse Tyson?

  When your orbit is not circular, when it's elliptical, you are moving faster in your orbit when you're closer, and slower in your orbit when you're farther away. Okay. So, the point is, if you are tidally locked and in a perfectly circular orbit, for every little bit around the Earth you revolve, you will rotate a little bit, always keeping that same face pointed. So everything works out. But if you're going a little faster than average, or a little slower than average, that little bit that you rotate doesn't line up as it would if you were in a perfectly circular orbit. It lines up on average.

• 6:45Neil deGrasse Tyson?

  But if you're if you're sort of fast in your orbit, then that little bit that you turn doesn't quite compensate for how far you've gone around the earth. And if you're slow in your orbit, you haven't quite turned enough.

• 6:58Chuck Nice?

  Right.

• 6:59Neil deGrasse Tyson?

  So when you look at time lapse photos of the moon, it is it is striking to behold. The moon is like it's it's it's like turning a little to the left to you, a little to the right. So we can see more than 50% of its surface over the duration of a moonth.

• 7:21Chuck Nice?

  Okay.

• 7:21Neil deGrasse Tyson?

  Month, excuse me.

• 7:22Chuck Nice?

  A a a moonth, I like that better. It's the month on a moon.

• 7:25Neil deGrasse Tyson?

  It was the original word, of course.

• 7:26Chuck Nice?

  A moonth, yeah. Well, go ahead.

• 7:30Neil deGrasse Tyson?

  Yeah, yeah. So and yes, to the extent that there's a wobble and anybody cares about it, that's true anytime you have a rotating object where it's not perfectly spherical. If there's a slight bit of mass off to the side, then there are extra torques on it, and that'll sort of bob as it turns. We wobble on our axis because of forces that are tugging on us, like such as the moon, as we rotate and as we go around the sun. So you do get this sort of wobbling and bobbing. But for me, the most the fun thing is the libration. If you just Google libration of the moon and and look at the time lapse video, it's it's it's it's striking because you don't get to see it that way because we see the moon once a night, you know,

• 8:15Neil deGrasse Tyson?

  or once a day. And when you time lapse it for a month,

• 8:18Chuck Nice?

  So it's it's kind of like the face that it shows us just turns a little bit.

• 8:23Neil deGrasse Tyson?

  Yeah, exactly. I should thank you. That's way easier. That's what I should have done, a little to the left.

• 8:27Chuck Nice?

  Right.

• 8:27Neil deGrasse Tyson?

  A little to the right.

• 8:28Chuck Nice?

  Right, so it's like when it when it's 25,000 miles out, it's like latte gray. And when it's like right close to us, it's like blue steel. So.

• 8:40Neil deGrasse Tyson?

  And I even know what blue steel means, that's embarrassing. Okay.

• 8:45Chuck Nice?

  Not really. That's, that's not really embarrassing. You were in the movie.

• 8:50Neil deGrasse Tyson?

  I was in Zoolander 2, that's right.

• 8:52Chuck Nice?

  That's right.

• 8:52Neil deGrasse Tyson?

  And I did do a blue steel imitation. I did. In fact, it's the very final thing you see in the movie. I, I am the last thing you see in the movie Zoolander 2.

• 9:04Chuck Nice?

  And anyone listening, please go look at that.

• 9:08Neil deGrasse Tyson?

  No, that's hilarious.

• 9:09Chuck Nice?

  Please don't look at it. Please go look at that. Because I believe you're wearing a fur coat too, which is.

• 9:15Neil deGrasse Tyson?

  I know, it's, it's a, it's a, it's a shoulder wrap for, it's not, I don't think it's a full coat. I think it was just something around my upper shoulders and neck.

• 9:24Chuck Nice?

  Yeah, like a, like a, they called that a stole back in the.

• 9:27Neil deGrasse Tyson?

  Stole, it was a stole, right, right, right. And then I sort of turned my head and then I make, give the expression. Just to be clear Chuck.

• 9:33Chuck Nice?

  Yeah.

• 9:33Neil deGrasse Tyson?

  Okay.

• 9:34Chuck Nice?

  Okay.

• 9:34Neil deGrasse Tyson?

  I've been in four movie franchises. Okay. And for three of them, there were no more movies made after I was in it.

• 9:48Chuck Nice?

  That's pretty damn hilarious.

• 9:49Neil deGrasse Tyson?

  Okay, so I, I was in, I was in Ice Age 5.

• 9:56Chuck Nice?

  Okay.

• 9:57Neil deGrasse Tyson?

  And the critics said, it's about time the series went extinct like all the creatures in it.

• 10:04Chuck Nice?

  Oh damn. Oh my.

• 10:06Neil deGrasse Tyson?

  I thought it was a pretty good movie though, because, because it had a lot of science in it. So I was, I was science biased, that's why I was one of the characters. So that was the last of the Ice Ages. I was in Sharknado 6.

• 10:18Chuck Nice?

  Okay.

• 10:19Neil deGrasse Tyson?

  You didn't know there were five others, did you?

• 10:20Chuck Nice?

  Well, I did not, number one.

• 10:22Neil deGrasse Tyson?

  Okay.

• 10:23Chuck Nice?

  And I'm so glad to hear that there's not a Sharknado 7.

• 10:28Chuck Nice?

  I'm just saying.

• 10:29Neil deGrasse Tyson?

  So unlike The Fast and the Furious.

• 10:32Chuck Nice?

  Could you please be in that? Please be in that.

• 10:34Neil deGrasse Tyson?

  No, but I don't want to kill the franchise.

• 10:36Chuck Nice?

  I do, and that's why I want you in it.

• 10:37Neil deGrasse Tyson?

  That's why you want, oh, you want me to be, so that the franchise dies.

• 10:41Chuck Nice?

  Exactly. I just want the last scene to be you like cruising like, yo, what up?

• 10:47Chuck Nice?

  Keep looking up, not while you're driving.

• 10:50Neil deGrasse Tyson?

  Not while you're driving. All right, give me another question.

• 10:52Chuck Nice?

  Okay, here we go. Uh, Zach Metcalf wants to know this. Uh, good morning, gentlemen. Uh, have anatomically modern human beings always lived under the same night sky? Have the stars had time to migrate and rearrange themselves in approximately 150,000 years that we've been looking up?

• 11:15Neil deGrasse Tyson?

  Love that question. So first of all, the dude knows that however fixed the stars look like they are on the night sky, in fact, they are moving through space.

• 11:26Chuck Nice?

  Yep.

• 11:27Neil deGrasse Tyson?

  And obviously, the farther away something is, the less from day to day you're gonna notice that it's moving.

• 11:33Chuck Nice?

  Right.

• 11:33Neil deGrasse Tyson?

  So that's, that's true on Earth as well. This is what led to the old childhood, uh, concept where you say, mommy, daddy, why is the moon following me?

• 11:46Chuck Nice?

  Right.

• 11:47Neil deGrasse Tyson?

  As you walk down the street. Because the trees go by and the buildings go by and the moon is just there. Well, if you kept walking for a million more miles, you would leave the moon far behind. So you're just not walking far enough for something that distant to reveal the fact that you're walking past it. So the farther away something is, the less obvious its motion is to you. Okay?

• 12:11Chuck Nice?

  Cool.

• 12:12Neil deGrasse Tyson?

  So, the, uh, so we have all the stars in the night sky and they're part of the solar neighborhood. How's that for a friendly phrase that we use? It's a solar neighborhood.

• 12:22Chuck Nice?

  You're now the, you're now the Mr. Rogers of the cosmos.

• 12:28Neil deGrasse Tyson?

  Welcome to the neighborhood.

• 12:30Chuck Nice?

  Yes. Hello, neighbor.

• 12:33Neil deGrasse Tyson?

  Oh, you're about to explode as a supernova. Oh, let me get the hell out of the neighborhood. Okay. That would be an interesting.

• 12:39Chuck Nice?

  Excellent.

• 12:40Neil deGrasse Tyson?

  All right. So, uh, we're all orbiting sort of the center of the galaxy together, but even with that sort of community movement, there is movement among us. Okay.

• 12:49Chuck Nice?

  Right.

• 12:50Neil deGrasse Tyson?

  So if you go back Seventy-five thousand years, we were anatomically human. Hundred thousand years ago, you would not recognize most of the constellations of the night sky.

• 13:00Chuck Nice?

  What?

• 13:01Neil deGrasse Tyson?

  That's right. That's right.

• 13:02Chuck Nice?

  Oh, man!

• 13:03Neil deGrasse Tyson?

  Well, not most. I would say about half. The nearby, the stars that are nearby us, that trace out the constellations, they'd be in a completely different place.

• 13:10Chuck Nice?

  Amazing.

• 13:11Neil deGrasse Tyson?

  So, for example, the Big Dipper, which we know of as looking like in the, in,

• 13:16Neil deGrasse Tyson?

  where is it? In England, is it called the, uh, the Big Sauce Pan?

• 13:20Chuck Nice?

  The Big Ladle?

• 13:21Neil deGrasse Tyson?

  Ladle. Ladle is the Little Dipper. The Little Dipper, the handle bends the other way like a ladle would. Okay? And the Big Dipper. Point is, all the stars of the Big Dipper, believe it or not, are part of a coherent star cluster.

• 13:34Chuck Nice?

  Hmm.

• 13:35Neil deGrasse Tyson?

  We're just really close, so you don't think of them as a tight cluster. But, so they're all sort of together, and they're moving in their own sort of orbits. And the Big Dipper would get flattened out, it turns out. We've done the math on this.

• 13:46Chuck Nice?

  Wow!

• 13:47Neil deGrasse Tyson?

  You just wouldn't recognize it as a Big Dipper at all. Okay, give me some more.

• 13:50Chuck Nice?

  Um, Teresina, no last name, like Cher, just Teresina. And Teresina says, "Hey Neil, hey Chuck, why is Mercury the element?" Okay? Very nice clarification there, Teresina.

• 14:06Neil deGrasse Tyson?

  Uh, liquid. She's talking to an astrophysicist. She gotta, she gotta...

• 14:09Chuck Nice?

  You gotta make that clarification, yes. She says, "Why is Mercury the element liquid? The elements before and after it in the periodic table, gold and thallium, are both solid at ambient temperature, so why does one proton make such a difference?"

• 14:30Neil deGrasse Tyson?

  Ooh!

• 14:30Chuck Nice?

  Oh, I love that question because I have no idea why.

• 14:33Neil deGrasse Tyson?

  Well, I'll get to that question when we return, after our first break on StarTalk Cosmic Query.

• 14:54Chuck Nice?

  Hi, I'm Chris Cohen from Hallworth, New Jersey, and I support StarTalk on Patreon. Please enjoy this episode of StarTalk Radio with your and my favorite personal astrophysicist, Neil deGrasse Tyson.

• 15:22Neil deGrasse Tyson?

  Chuck, we're back, Cosmic Aquarium.

• 15:23Chuck Nice?

  Okay.

• 15:24Neil deGrasse Tyson?

  Grab bag.

• 15:25Chuck Nice?

  Grab bag.

• 15:26Neil deGrasse Tyson?

  Questions coming from everywhere.

• 15:27Chuck Nice?

  Yep, that's right.

• 15:29Neil deGrasse Tyson?

  From left field, right field, behind home plate.

• 15:31Chuck Nice?

  That's when you know a fan is mad.

• 15:34Neil deGrasse Tyson?

  Oh, if it comes from behind home plate?

• 15:36Chuck Nice?

  If it comes from behind home plate.

• 15:37Neil deGrasse Tyson?

  No, if they throw it at your head, then they're mad at you.

• 15:39Chuck Nice?

  Yeah, exactly.

• 15:41Neil deGrasse Tyson?

  So, this last question was from Terasina. Who was this?

• 15:45Chuck Nice?

  Yep, Terasina, who says, "Hey Neil Chuck, why is mercury the element liquid? The elements before and after in the periodic table are both solid at ambient temperature, so why does one proton make such a difference?"

• 15:59Neil deGrasse Tyson?

  Okay, I can answer that. I don't have a good idea. I don't know.

• 16:06Chuck Nice?

  Wow, okay.

• 16:08Neil deGrasse Tyson?

  Well, I mean, I can fumble through an answer, okay? I will give you an answer, but it will be wholly unsatisfying, because I don't have a deep understanding of it, but I can give you an answer, and here it is. You ready?

• 16:20Chuck Nice?

  All right.

• 16:21Neil deGrasse Tyson?

  Okay.

• 16:22Chuck Nice?

  Because I said so. Because it's nature.

• 16:26Neil deGrasse Tyson?

  Thank you, Chuck. Next question.

• 16:29Chuck Nice?

  That clear it up for you? It's nature.

• 16:35Neil deGrasse Tyson?

  Crystal clear.

• 16:36Chuck Nice?

  There you go. All right, go ahead.

• 16:38Neil deGrasse Tyson?

  So... The, we say, how could only one proton in the nucleus make such a difference? Because you're comparing what was to the left of it and to the right of it on the periodic table. And the periodic table is an ascension of proton count in the nucleus of atoms. That's what that is. And you go from hydrogen at number one, one proton, up to uranium, ninety-two protons, and then the elements we create in the lab goes up to, I forgot where they're up to now, one hundred and twenty, something like that. So, so it turns out remarkably, what we learned from applying quantum physics to the periodic

• 17:20Neil deGrasse Tyson?

  table is that vertically on the table, elements have properties, chemical properties, similar to each other. So where you find carbon, for example, you look directly, what's directly below it? It's silicon. And so we're carbon-based life, so everyone is eagerly looking for silicon-based life. If carbon can make life in all these molecules that comprise life as we know it, silicon sitting right below it makes the same families of molecules as carbon does. And so, so elements in vertical columns, we've learned how and why that's so from quantum physics, has similar chemical properties. But the prop, but the melting point is not a chemical property.

• 18:05Neil deGrasse Tyson?

  It's actually intrinsic to the element itself. And so, so what happens when you change it, then the charge changes in the nucleus of the atom. And that changes the electron orbitals in response to it. Not orbits, but orbitals, we call them. Inspired by the orbits of planets, by the way. Because we thought maybe you have solar system with the sun in the middle and planets in orbit around it, as we start poking the atom, we say, it's got a nucleus, and it's got electrons. Maybe it's the same thing, but just little. And it's not. Whole other laws of physics apply there, and it's the realm of quantum physics. So, point is, mercury melts at about forty degrees below zero.

• 18:52Neil deGrasse Tyson?

  And so it's liquid that all degrees above that until it evaporates. And that's a unique property. So many elements on the periodic table have unique properties relative to everything around them that it's one of the reasons to celebrate that it exists at all. And it's a testament to the genius of chemists and physicists who go into those elements and say, this has this property. So I want to do this other thing with it. This conducts electricity. This does not conduct electricity. This is brittle. This is flexible. This is gaseous. This is liquid. And so we've gone all into the periodic table and basically constructed civilization based on it.

• 19:36Neil deGrasse Tyson?

  So I don't have a good answer for you because I don't know what to tell you about why that's liquid and nothing around it is, left or right or up or down. But I can tell you, being liquid is not the most it's not the most different thing about an element that you can find among elements on the periodic table.

• 19:53Chuck Nice?

  Wow, okay.

• 19:54Neil deGrasse Tyson?

  And by the way, if we lived in a world that was 50 below zero, you wouldn't be asking this question. Mercury would be solid like every other element. Okay, we can go to a warmer environment and you'd find some things that then become liquid. And you might be asking that about those other elements. So the fact that we are okay in these quote room temperatures has consequences for which elements on the periodic table are solid, liquid, or gas.

• 20:24Chuck Nice?

  Wow.

• 20:25Neil deGrasse Tyson?

  So that's me dancing around the fact that I don't actually know the answer to that question.

• 20:29Chuck Nice?

  Okay, so for somebody who, I'd hate to know if you knew the answer.

• 20:35Chuck Nice?

  God, we'd be here till next year if you actually knew the answer.

• 20:41Neil deGrasse Tyson?

  What I'll do is I'll do some homework on it and I'll come back and see what I can tell about the relationship of one mercury atom to another and why it is that at this temperature, unlike every other metal on the periodic table, that they don't make a solid lattice. I'll find out and I'll get back to it.

• 21:02Chuck Nice?

  All right, well, thanks, Terasina, for giving Dr. Tyson some homework.

• 21:07Neil deGrasse Tyson?

  Yeah, okay.

• 21:08Chuck Nice?

  All right, let's, here we go. This is.

• 21:12Neil deGrasse Tyson?

  Oh, by the way, there's an element, and I forgot which element. Forgive me, I'll dig it up the next time I return. There's an, in the UK. Uh, the ambient indoor temperature, lab temperature, is slightly lower than in the United States, or in Germany, or in France. And so, when the UK folks made their periodic table, there's an element that they listed as liquid. But in the United States, and France, and everywhere else, it was listed as so, um, I'm sorry, listed as solid, but for everybody else, it was liquid.

• 21:42Chuck Nice?

  Wow.

• 21:43Neil deGrasse Tyson?

  Yeah, so-

• 21:44Chuck Nice?

  And just from a slight variation in the lab?

• 21:48Neil deGrasse Tyson?

  Yeah, just because the ambient lab temperature in England is about, you know, five degrees cooler than the ambient lab temperature in other sort of industrialized states at the time. So, the point is, if you want to think of the periodic table as some deep fundamental truth about the universe, then you should not be distracting yourself about whether it's solid, liquid, or gas at your laboratory temperature. Because the universe doesn't give a rat's ass about your laboratory temperature.

• 22:15Chuck Nice?

  Hmm.

• 22:16Neil deGrasse Tyson?

  That's not a fundamental truth about the element, whether it's liquid in your lab.

• 22:21Chuck Nice?

  Uh, yeah, there you go. Don't you know who I am? I'm the universe.

• 22:25Neil deGrasse Tyson?

  Thank you.

• 22:26Chuck Nice?

  You want me to think, what? You're, what you saying? You're cold? You need a sweater? I'm the universe. Are you kidding?

• 22:36Neil deGrasse Tyson?

  That's right. Yeah, so, uh, yeah, so there-

• 22:38Chuck Nice?

  You think this is cold? I'm at an absolute zero, all, well, a couple degrees above it, all the time.

• 22:45Neil deGrasse Tyson?

  And you know the methane that comes out of your stove, if you use a gas stove?

• 22:48Chuck Nice?

  Right.

• 22:49Neil deGrasse Tyson?

  Um, on Earth, that's gaseous. You go to Saturn's moon Titan-

• 22:53Chuck Nice?

  Right.

• 22:54Neil deGrasse Tyson?

  It has the right combination of temperature and air pressure to liquefy methane.

• 22:59Chuck Nice?

  Hmm. Swimming in methane, that just sounds like a dream.

• 23:04Neil deGrasse Tyson?

  And, and the water, it is so cold that the water has frozen so solid, that it's basically the bedrock on the planet. There are boulders, and it's just ice. But that, those are the rocks. And think about it, inside a volcano, what happens to rock?

• 23:21Chuck Nice?

  It melts.

• 23:21Neil deGrasse Tyson?

  It melts. So if we're in an environment that's as hot as a volcano, you would not think of rocks as anything solid. You say, oh, that's a liquid. Let's take a bath. And so, so these conditions that you happen to live in are not themselves fundamental to, to what's going on on the periodic table.

• 23:40Chuck Nice?

  Wow, there you go. All right, Tarasina, we got more out of that than I ever thought for somebody who said that I don't know.

• 23:49Chuck Nice?

  Only physicists and astrophysicists answer questions that they don't know for six minutes.

• 23:58Chuck Nice?

  All right, here we go. Here we go. This is Jordan Belikanas. Uh, he says, hey.

• 24:04Neil deGrasse Tyson?

  Oh, wait, wait, wait. One other thing.

• 24:06Chuck Nice?

  Okay.

• 24:06Neil deGrasse Tyson?

  There are places on Mars where the temperature and the air pressure, the atmospheric pressure, are just right, that water, if you live there, water would freeze, melt, and boil all at the same time.

• 24:27Chuck Nice?

  Um, what?

• 24:35Neil deGrasse Tyson?

  So you can have, you can have a bowl of water with ice cubes in it, and the water is boiling, and that's stable.

• 24:45Chuck Nice?

  That's, that's pretty, okay, I don't, I was gonna say that's hot, but it's not, so.

• 24:49Neil deGrasse Tyson?

  It's, it's.

• 24:50Chuck Nice?

  And I was gonna say it's cool, but it's, okay, that's hot and cool, and that's everything.

• 24:55Neil deGrasse Tyson?

  That's everything, if to say it's not hot, it's good. It's not tepid, right? So that it's called a triple point, and water has a triple point of atmospheric pressure and temperature where all states, three states of matter can coexist happily. And so, yeah, that's why you can say water is liquid. No, water is only liquid when you make it a liquid. Okay?

• 25:16Chuck Nice?

  Right.

• 25:16Neil deGrasse Tyson?

  Otherwise, it's solid or gaseous.

• 25:18Chuck Nice?

  All right, cool.

• 25:19Neil deGrasse Tyson?

  There you go.

• 25:20Chuck Nice?

  All right. All right, Jordan Belikanas. Uh, yep, he says, hey, Dr. Tyson and Chuck, what's happening? I never have been able to understand the thought of terraforming Mars. Hmm. Considering, listen, here's the real thing. It's a dead planet with no magnetic field. It seems solar wind and extreme UV would strip the atmosphere and kill any life anyway. Can you please help explain how this would ever work?

• 25:53Neil deGrasse Tyson?

  Okay, so, so he's, he's two steps ahead of someone who might have only just now heard of terraforming. So terraforming is you take a dead planet and then you, you, you seed the, the atmosphere with, with aerosols or you, you introduce microbes that will thrive on the carbon dioxide and might output oxygen. And then you step back and let it run its thing if you put in the right cocktail. And then out comes an arable, green planet that you've just terraformed. That's not an impossible dream, okay? It's not, I mean, Earth was terraformed early on by Earth itself, right? So the question is, can you do it like fast?

• 26:37Neil deGrasse Tyson?

  If you have to leave Earth and you gotta find another place to do it.

• 26:41Chuck Nice?

  They did in the one Star Trek movie.

• 26:43Neil deGrasse Tyson?

  They did, in the movie, yes, yes, it was the Genesis.

• 26:45Chuck Nice?

  The Genesis, that's what it was called.

• 26:47Neil deGrasse Tyson?

  The Genesis Project, right. They took some pod or something and sent it down and it, uh, I think it was a pod. No, no, no, the pod was somebody's dead body that then came back to life.

• 26:58Chuck Nice?

  Oh, Spock, yeah.

• 26:59Neil deGrasse Tyson?

  Spock, yeah, yeah, yeah.

• 27:00Chuck Nice?

  Cool.

• 27:01Neil deGrasse Tyson?

  Okay, so Jordan is worried that because Mars does not have a magnetic field, which would then shield it from, uh, uh, solar wind, whose energy can break apart molecules or have ozone that would protect it from ultraviolet. All of these, without these protections, life on Earth, we don't know how you would sustain it. Okay, that's fine. Consider that if you're living underground, none of that matters.

• 27:28Chuck Nice?

  Oh, there you go.

• 27:30Neil deGrasse Tyson?

  Shield yourself from the sun, none of that matters.

• 27:33Chuck Nice?

  Martian more locks.

• 27:34Neil deGrasse Tyson?

  I forgot.

• 27:37Chuck Nice?

  Yeah, Martian more locks, that's what we got.

• 27:39Neil deGrasse Tyson?

  So, the, first of all, you can just shield yourself from it. Second, if we have the power of geoengineering.

• 27:45Chuck Nice?

  Right.

• 27:45Neil deGrasse Tyson?

  To turn Mars into an arable place, I don't see why we couldn't figure out some way to deflect the solar wind. Or to, or to block out UV. I'm not worried, that's like an engineering challenge. And engineers tend to solve problems when given the task. Um, and so I'm not, I'm not worried about that. It's the rest that is way more complex. We know how to block UV. We know how to block the solar wind. We don't know how to, how to send in microbes and come back 10 years later and have a forest. We just don't know how to do that. That's where the challenges are right now.

• 28:19Chuck Nice?

  Gotcha, gotcha. So we got the sunscreen covered.

• 28:23Neil deGrasse Tyson?

  Exactly.

• 28:25Chuck Nice?

  That, that part's good.

• 28:26Neil deGrasse Tyson?

  Yeah, yeah, we good. We, we good.

• 28:29Chuck Nice?

  All right. All right. Well, there you go, Jordan. I mean, at least you're thinking two steps ahead of anybody else who's talking about terraforming. Good for you. All right, here we go.

• 28:39Neil deGrasse Tyson?

  Oh, by the way, if you can, if you can, if you have good geoengineering, you might find a way to stir up the Martian core so that it can then generate another magnetic field. I mean, what's stopping us?

• 28:51Chuck Nice?

  Right.

• 28:52Neil deGrasse Tyson?

  Yeah, Earth gets its magnetic field from our iron core.

• 28:55Chuck Nice?

  From the iron core that's spinning inside of us.

• 28:57Neil deGrasse Tyson?

  Yeah, yeah. Inside of that is, has this moving iron, which is conductive. And when you have a conductive, moving material, it can generate currents and currents generate magnetic fields. So Mars, that's all stopped long ago, but why not, if we can control planets, go stir it up again.

• 29:14Chuck Nice?

  Right. See, Mars, that's why nobody finds you attractive. Cause you have a magnetic field.

• 29:20Neil deGrasse Tyson?

  Oh, just, oh, don't.

• 29:22Chuck Nice?

  I just made that up. Come on, man.

• 29:24Neil deGrasse Tyson?

  Okay, all right. You don't have to test it on this program.

• 29:30Neil deGrasse Tyson?

  Go to open mic night and see how people did.

• 29:36Chuck Nice?

  Damn. Oh my.

• 29:39Neil deGrasse Tyson?

  Boy, that was, that's a good comedic dig though.

• 29:42Chuck Nice?

  Oh, oh my goodness. Damn.

• 29:45Neil deGrasse Tyson?

  Chuck is wiping away his tears now.

• 29:47Chuck Nice?

  Oh man, cause you got me with that one, man. You ain't gotta test it out here.

• 29:54Neil deGrasse Tyson?

  Test it out on my show.

• 29:58Chuck Nice?

  Oh man, I need some Visine now.

• 30:02Chuck Nice?

  All right.

• 30:02Neil deGrasse Tyson?

  All right, Chuck, we gotta take a quick break.

• 30:03Chuck Nice?

  Oh, okay. All right.

• 30:04Neil deGrasse Tyson?

  We'll come back to segment number three of StarTalk Cosmic Aquarius. Grab that. Be there.

• 30:21Chuck Nice?

  You know what time it is? It's Patreon shout out time. John Turnham, Andrew Nelson, Hansa Rec. Thanks so much for your support, guys. You make this whole thing possible. And for those of you who would like your very own Patreon shout out, please go to patreon.com/stargtorkradio and support us.

• 30:54Neil deGrasse Tyson?

  All right, we're back. StarTalk Cosmic Queries. Chuck, you're tweeting at Chuck Nice Comic.

• 31:00Chuck Nice?

  Yes, thank you, sir. That's correct.

• 31:01Neil deGrasse Tyson?

  I do indeed follow you. I don't follow many things. I follow you. Just let you know.

• 31:05Chuck Nice?

  Well, that's great. I followed you first, so.

• 31:10Neil deGrasse Tyson?

  I can't top that, sorry.

• 31:11Chuck Nice?

  There you go.

• 31:13Neil deGrasse Tyson?

  All right, what are the questions you got for us? We've got one segment left. Let's see how many we can squeeze in.

• 31:17Chuck Nice?

  Let's see what we can do here. This is Abinav Yadav. Hello, Dr. Tyson and Sir Nice. I'm excited to be asking my very first question. Now, you have spoken about the, about moon disrupting observation time.

• 31:34Neil deGrasse Tyson?

  Oh, yeah.

• 31:35Chuck Nice?

  Are there places in the solar system that are much better for it? Where this doesn't exist, somewhere we can just send telescopes and observe? Love the show.

• 31:48Neil deGrasse Tyson?

  Yeah, that, that's, there's a lot going on in that question. So let me just unpack it briefly. So first of all, the full moon at night is crazy bright.

• 31:59Chuck Nice?

  Right.

• 32:00Neil deGrasse Tyson?

  In fact, it's something like six times brighter than a half moon because of the way the laws of reflection work.

• 32:07Chuck Nice?

  Okay.

• 32:07Neil deGrasse Tyson?

  You think it'd only be like twice as bright? It's like even brighter. So on a moonless night, you, the unaided eye can see a couple of thousand stars. If the moon is out, you can see a couple of hundred stars. So it drops it by a factor of 10. So if you're trying to see the deep universe, we have what's called dark time at telescopes. And it's highly competitive to gain access to a telescope while the moon is not up. Okay, it's called dark time. And then people who are on the brink of the detection of things will ask for dark time. So then we learned, well, why be on Earth at all? Why, okay, but if you go into orbit, the moon is still there, okay?

• 32:49Neil deGrasse Tyson?

  Now, the sky is not as bright, but it's still kinda, you don't wanna look near the moon. You have scattered light into your telescope beam. So, how about a million miles on the other side of the moon? How about that? Well, that's where the James Webb Space Telescope is going.

• 33:10Chuck Nice?

  Oh, cool.

• 33:11Neil deGrasse Tyson?

  Ooh, yeah, so it's far away from Earth and from the moon. And so, yeah, we're doing our darndest to get rid of the interference that we're now experiencing. But let me stay at it. There's radio interference, and we have radio wave telescopes.

• 33:26Chuck Nice?

  Right.

• 33:26Neil deGrasse Tyson?

  So what are we gonna do about that? There's all this talk, whole conferences given, unto putting radio telescopes on the far side of the moon.

• 33:34Chuck Nice?

  Wow.

• 33:35Neil deGrasse Tyson?

  Because the moon only shows one face, so if you're on the far side, you will never see Earth, ever.

• 33:40Chuck Nice?

  Right.

• 33:41Neil deGrasse Tyson?

  Okay, so that famous photo of Earth rise over the moon by Apollo 8? Okay, Earth doesn't rise on the moon.

• 33:48Chuck Nice?

  Right.

• 33:48Neil deGrasse Tyson?

  It never does. It's either always there or never there. Because you're either on the side of the moon that faces Earth, or the side of the moon that faces elsewhere. And so the reason why that's called Earth rise is because they were orbiting the moon.

• 34:05Chuck Nice?

  Right.

• 34:05Neil deGrasse Tyson?

  And when you're orbiting, then the sky rises and sets, and so they caught the rising Earth on the lunar landscape. So it's legitimately Earth rising, it's just highly misleading.

• 34:16Chuck Nice?

  Right.

• 34:16Neil deGrasse Tyson?

  That's all.

• 34:17Chuck Nice?

  It's like Moon Haiti and Moon Dominican Republic. So, just same island, just one side is Haiti and the other side is Dominican Republic.

• 34:27Neil deGrasse Tyson?

  Is it really the first, I'm talking the universe here, and you're talking geopolitics?

• 34:31Chuck Nice?

  Man, I need a vacation.

• 34:32Neil deGrasse Tyson?

  That's evidently.

• 34:34Chuck Nice?

  I'm really just thinking about tropical places, that's all.

• 34:38Neil deGrasse Tyson?

  That's right, but they are the same island, and somebody just cut a line right down the middle.

• 34:42Chuck Nice?

  Cut a line, that's it?

• 34:43Neil deGrasse Tyson?

  Right, alright, so, yeah, so we are thinking about that, and it is a big problem. And so wherever the electromagnetic spectrum is noisiest, we try to do our darndest to avoid it. And sometimes it means going into space to the far side of the moon, and even into deep space itself.

• 35:01Chuck Nice?

  Wow, cool, man.

• 35:02Neil deGrasse Tyson?

  Yeah, yeah.

• 35:03Chuck Nice?

  Alright, so, okay, now, what probe?

• 35:08Chuck Nice?

  Just got out of our solar system. And will we be able to receive, so I'm just thinking about telescopes.

• 35:15Neil deGrasse Tyson?

  Oh, you're talking about Voyager.

• 35:16Chuck Nice?

  Voyager.

• 35:17Neil deGrasse Tyson?

  Yeah, so.

• 35:18Chuck Nice?

  Will we be able to get, retrieve any information from that ever?

• 35:21Neil deGrasse Tyson?

  In principle, but the cost of maintaining that relative to other things. We have what's called a senior review of projects that are growing long of tooth that have been going for a while, even if they're giving trickles of data. You say to yourself, it costs this much. What is the incremental knowledge we're gleaning about our state of the universe relative to this new project that is looking for C funding to discover something new and exciting? And so sometimes you gotta turn off the switch. Voyager, we turn off the switch after it exited the influence of the sun. There's everyone thinking, oh, the solar system ends at Pluto. No, solar system keeps going.

• 36:00Chuck Nice?

  Right.

• 36:00Neil deGrasse Tyson?

  All right, and one way to think about it is, as long as you're near enough to the sun to feel its sort of magnetic field and other effects, you say, I'm part of the solar system. But the galaxy has a magnetic field also.

• 36:15Chuck Nice?

  Right.

• 36:15Neil deGrasse Tyson?

  So if you start getting farther and farther away from the sun, the strength of the sun's magnetic field drops and the strength relative to the strength of the galactic magnetic field. You reach a point, oh, by the way, it's not just magnetic field, but the particle stream emanating from the sun.

• 36:33Chuck Nice?

  Right.

• 36:34Neil deGrasse Tyson?

  Relative to the ambient particle stream in the galaxy. You reach a point where you can no longer tell the difference between those two. Bada bing, you've left the solar system.

• 36:43Chuck Nice?

  Cool.

• 36:44Neil deGrasse Tyson?

  Yeah.

• 36:44Chuck Nice?

  All right.

• 36:45Neil deGrasse Tyson?

  That's how you think about that.

• 36:46Chuck Nice?

  All right, that's how you think about it. All right, cool. And since we're talking telescopes here, when you talk about observation time earlier. If you're an important.

• 36:57Neil deGrasse Tyson?

  Are you asking a question now?

• 36:59Chuck Nice?

  No, I'm just. You know, this is still, um, uh, Abenov. Yeah.

• 37:05Neil deGrasse Tyson?

  Okay, I was just, you know, because you've got to become a Patreon member if you're going to ask me a question, that's all. I'm just checking. Go on, because you, you got all the data there, so.

• 37:13Chuck Nice?

  Yeah, I'm also, I'm also lying, but hey.

• 37:20Chuck Nice?

  No, here's what I would know. If you're an important scientist, do you get bumped up in your, uh, your request for observation time? Are they just like, Jimmy, please, you're really that research? Get out of here.

• 37:33Neil deGrasse Tyson?

  Yeah, your seniority has nothing to do with it. It's how brilliant is your idea? And that's why on our research papers, we don't put their, your earned degrees next to your name. All right, so, uh, a, an undergraduate, you know, one of these sort of precocious research interested graduate students could have their name right next to someone who's highly senior or even a Nobel laureate. No degrees are put there, no, no such distinctions are made.

• 38:00Chuck Nice?

  Oh my God, it's the masked physicist.

• 38:07Chuck Nice?

  Instead of the masked singer, it's masked physicist.

• 38:10Neil deGrasse Tyson?

  Yeah, so we, we don't, and I think that's one of the, um, uh, that's an important feature of the entire enterprise. Now, if you have an idea that's a little crazy, that it's not getting past any reviews, the director of the telescope has what's called director's discretionary time. And they can say, you know, I want to give this, this a shot.

• 38:31Chuck Nice?

  Oh, wow.

• 38:32Neil deGrasse Tyson?

  And they can grant the time and it won't have to go through the, the peer review to be given the time.

• 38:37Chuck Nice?

  Oh.

• 38:38Neil deGrasse Tyson?

  But ultimately, the research you do based on it would have to be peer reviewed if you're going to publish it.

• 38:42Chuck Nice?

  Okay, uh, that's a great system, by the way.

• 38:46Neil deGrasse Tyson?

  And by, it is, it is. And by the way, the very famous Hubble Deep Field, do you know that picture that has just galaxies in it?

• 38:52Chuck Nice?

  Yes, it's beautiful.

• 38:53Neil deGrasse Tyson?

  And there's a couple of stars, but everything you might think is a star is an entire galaxy.

• 38:57Chuck Nice?

  Yeah.

• 38:58Neil deGrasse Tyson?

  That was allocated on director's discretionary time.

• 39:02Chuck Nice?

  Okay.

• 39:03Neil deGrasse Tyson?

  And it became one of the most significant images ever taken by the telescope. And you know who received that discretionary, that director's discretionary time?

• 39:10Chuck Nice?

  No.

• 39:11Neil deGrasse Tyson?

  The director, he gave it to himself.

• 39:14Chuck Nice?

  No!

• 39:15Neil deGrasse Tyson?

  Yes.

• 39:15Chuck Nice?

  Get out!

• 39:16Neil deGrasse Tyson?

  Yes!

• 39:17Chuck Nice?

  Oh, that's tremendous.

• 39:19Neil deGrasse Tyson?

  Yes, is that badass?

• 39:21Chuck Nice?

  He was like, you know what, man?

• 39:23Neil deGrasse Tyson?

  That's gangster.

• 39:25Chuck Nice?

  You know, I'm, I wanna look out into nothing.

• 39:29Neil deGrasse Tyson?

  And there's nothing you could, you can't stop it.

• 39:30Chuck Nice?

  Why would you point the telescope that way? There's nothing there. Because I can, alright? I'm the director.

• 39:41Chuck Nice?

  I'm the HDIC, the head director in charge, biatch. Okay.

• 39:49Neil deGrasse Tyson?

  So, the funny thing is, you, you're absolutely right. The Hubble Deep Field was a spot on the sky that was the least interesting spot you can possibly find. There were no interesting stars, no previously discovered interesting galaxies, black holes, right? Nothing! And he says, "Let me take the most potent, powerful telescope in the world and aim it there and hang there and let those meager photons accumulate and let's see what's lurking in the dark." Thus was born the Hubble Deep Field. It may have been the most significant image taken by the telescope itself. And so, we, we allow for that kind of creative thinking that might not otherwise get through.

• 40:31Chuck Nice?

  That's, by the way, what a great story.

• 40:34Neil deGrasse Tyson?

  I'm telling, I love my people, these are my people.

• 40:36Chuck Nice?

  I mean, seriously, that's probably equally as exciting as the discovery itself. Alright, uh, this is Dale Buin and Dale says, "Hey Neil, photons don't experience time, they don't ever decay. Would they decay, uh, wait a minute, would they decay if they did experience time?"

• 41:02Neil deGrasse Tyson?

  Yeah, so decay means you are this... This form of matter in one moment and later on you're a different form of matter. And you can time that out and there's usually some variance there. But there's a very tight average that we give for like it's called the half-life. Uh, for example, carbon 14.

• 41:21Chuck Nice?

  Right.

• 41:22Neil deGrasse Tyson?

  Um, any radioactive element has a half-life. Well, if all the atoms know that they're supposed to convert within some statistical timeframe, then they must have a measure of time. There must be some kind of clock going on within them. All right. Photons moving at the speed of light, time stops for them. So if you have no measure of time, then you cannot know to turn into anything else later in life because there is no later. If photons did happen to experience time, it means they would not be going at the speed of light. Okay. And they would not be pure energy as they currently are. And then they would have the ability to transform into another kind of particle.

• 42:06Chuck Nice?

  Wow.

• 42:07Neil deGrasse Tyson?

  Yeah.

• 42:08Chuck Nice?

  That is so trippy, man. Oh my God, that is so trippy. Okay.

• 42:13Neil deGrasse Tyson?

  Because they would know how to keep time. And if you know how to keep time, you would have some clock. And you say, you know, in one year, five years, three seconds, a tenth of a second, I want to turn into another particle. Now, just because you have a clock doesn't mean you will turn into another particle. The other conditions have to be right. But if you don't have a clock, there's no reason or understanding we possibly have for why you would change into another.

• 42:37Chuck Nice?

  Okay. So photons are super gangster.

• 42:40Neil deGrasse Tyson?

  Gangster. So it means the photon that we detect here that was emitted in the early universe shortly after the big bang, uh, as far as it's concerned.

• 42:52Chuck Nice?

  It's still the big bang.

• 42:56Chuck Nice?

  Hey, let me tell you something, man. I'm a photon. I don't ride or die. I ride and die. I take the ride.

• 43:03Neil deGrasse Tyson?

  Always dying and always living at the same time. So it gets, so it is detected in the same instant that it is emitted.

• 43:11Chuck Nice?

  Right.

• 43:12Neil deGrasse Tyson?

  According to the photon itself. So that's fascinating. So life as a photon is, like you said, is a trippy thing.

• 43:19Neil deGrasse Tyson?

  Yeah.

• 43:19Chuck Nice?

  God, I love science.

• 43:21Neil deGrasse Tyson?

  Yeah.

• 43:21Chuck Nice?

  I mean, that is just amazing. Okay, let's get another one in here.

• 43:25Neil deGrasse Tyson?

  Maybe we can slip in another one, yeah.

• 43:27Chuck Nice?

  Okay, this is Nicholas Lenson. Nicholas says, hey Neil, hey Chuck. Given that the black holes lose mass slowly, but thoroughly until they no longer exist, would there be a point in time where the mass of the black hole is no longer sufficient to trap light?

• 43:47Chuck Nice?

  So the surface of the black hole would become visible. And what would that look like? So wait a minute, did this guy just discover a way to look inside of a black hole?

• 43:58Neil deGrasse Tyson?

  I, I, in principle, yeah.

• 44:01Neil deGrasse Tyson?

  So it turns out that any amount of mass, you can calculate how small it would have to be, how compressed it would have to be for it to become a black hole. So if you wanted Earth to become a black hole, you'd have to shrink it down to like the size of a plum. Last I did the math on that. So if you manage to do that, bada bing, you have an Earth black hole. The point is, a lower mass black hole is smaller than a higher mass black hole. If a black hole begins losing mass, it gets smaller and becomes the black hole size appropriate for the amount of mass it has.

• 44:37Chuck Nice?

  So.

• 44:38Neil deGrasse Tyson?

  So it's stuck being a black hole.

• 44:40Chuck Nice?

  Always gonna be a black hole.

• 44:43Neil deGrasse Tyson?

  Correct.

• 44:44Chuck Nice?

  No matter what the mass is, now that it has collapsed into a black hole, it can't be anything.

• 44:51Neil deGrasse Tyson?

  Correct.

• 44:52Chuck Nice?

  So if it continues to lose that mass, it will always maintain the properties of a black hole because it can't be anything.

• 45:00Neil deGrasse Tyson?

  As it shrinks down, that's right. Now, if for some magic force of nature, the black hole evaporates according to Hawking radiation, which, which your guy clearly knows about, and somehow did not get smaller, there would be a point where the density would no longer allow it to be a black hole. Because it's about the density, it's not about the mass. The density would know it. And then the black hole would slowly reveal itself as a solid object. So yeah, it was a great question. And if one day we can manipulate the laws of physics, then we could reach into a black hole, somehow prop up its, its, uh, shape. So that as it got less and less mass, the density would drop and then we could reveal what's inside. But then, at that point, you're no longer looking inside a black hole, are you?

• 45:44Neil deGrasse Tyson?

  You're just looking at a regular object.

• 45:46Chuck Nice?

  Right.

• 45:46Neil deGrasse Tyson?

  Yeah.

• 45:47Chuck Nice?

  Right. Because you really need that mass down to that small density in order for it to be.

• 45:54Neil deGrasse Tyson?

  And you know what happens? As the black hole continues to evaporate, the energy range that gets emitted becomes higher and higher and higher. So, large black holes are emitting like radio waves and smaller black holes will emit visible light. The tiniest of black holes will emit gamma rays. Okay? And it has to do with the size of the black hole, whether the wave that it emits can fit inside the black hole or not. That's the quantum physics of it. Hawking worked all this out. Point is, as it gets smaller and smaller and smaller and smaller, the very last bit, oh, by the way, the, as it gets smaller, the rate at which it gives off energy increases.

• 46:34Neil deGrasse Tyson?

  Okay? So, this becomes a runaway process where it gets smaller and smaller, faster and faster and faster. And the very last moment, it happens catastrophically and you get a little burst of gamma rays. So the original Hawking Radiation paper prompted people to look for little bursts of gamma rays, like in the universe, which could signal black holes dying, having completely evaporated.

• 46:58Chuck Nice?

  That is amazing!

• 46:59Neil deGrasse Tyson?

  Yeah.

• 47:00Chuck Nice?

  Okay.

• 47:01Neil deGrasse Tyson?

  Now, we do see bursts of gamma rays, but they don't match the spectrum of a dying black hole. But, but there it is. This is our universe we all live in. It's a beautiful place. Chuck, we're out of time.

• 47:11Chuck Nice?

  Aw, man.

• 47:13Neil deGrasse Tyson?

  Darn it!

• 47:15Chuck Nice?

  Darn it all!

• 47:17Neil deGrasse Tyson?

  Alright Chuck, that was fun. So, this is another StarTalk Cosmic Queries. It's, uh, uh, just questions from Patreon members. It was a, a grab bag. And I, I wanna go back to Galactic Gumbo, cuz I wanna hear you imitate this.

• 47:40Neil deGrasse Tyson?

  I missed that. I missed it too. We can't call a grab back. We'll find, we'll, we'll figure it out on the next, on the next timeout. All right, dude, good to have you always. Always a pleasure. This has been StarTalk Cosmic Queries. As always, Neil deGrasse Tyson here, bidding you to keep looking up.