Cosmic Queries – Black Hole Time Cloak with Charles Liu

Are black holes places or objects? Neil deGrasse Tyson and cohosts Chuck Nice and Gary O’Reilly answer grab-bag questions about distorting spacetime, Olbers’ Paradox, singularities, the shape of the universe, and more with astrophysicist Charles Liu.

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

• 0:00Neil deGrasse Tyson?

  Coming up on StarTalk, Cosmic Queries Grab Bag Edition, from right here at my office, the Hayden Planetarium, the American Museum of Natural History. Your questions this time touched on all kinds of wacky, weird things, like what happens in a black hole, out of a black hole, quantum entanglement, this universe, other universes, the shape of the universe, all of the above, and more, coming up.

• 0:35Neil deGrasse Tyson?

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

• 0:49Neil deGrasse Tyson?

  This is StarTalk. Neil deGrasse Tyson here, your personal astrophysicist. Today, it's gonna be Cosmic Queries Grab Bag. Chuck.

• 1:01Chuck Nice?

  Hey.

• 1:02Neil deGrasse Tyson?

  You the Grab Bag Man.

• 1:03Chuck Nice?

  Uh, no, I'm just part of the bag. I'm not really much of the grab. I'm part of the bag.

• 1:12Neil deGrasse Tyson?

  And we got Gary O'Reilly joining us here.

• 1:14Chuck Nice?

  Yeah.

• 1:15Neil deGrasse Tyson?

  And apparently, in previous Grab Bags, I was insufficient to serve the needs of the questions.

• 1:24Chuck Nice?

  Oh, you got that email.

• 1:25Neil deGrasse Tyson?

  So y'all went out and got one of my colleagues.

• 1:29Chuck Nice?

  Well, of course. It's all about sharing care.

• 1:31Neil deGrasse Tyson?

  Of sharing care. So, Charles Lu, a returning champion, and still champion. Charles Lu, friend and colleague, and we go back.

• 1:42Charles Liu?

  A long way.

• 1:43Neil deGrasse Tyson?

  Almost 30 years now.

• 1:44Charles Liu?

  What a pleasure.

• 1:45Neil deGrasse Tyson?

  Yeah.

• 1:45Charles Liu?

  It's been so fun.

• 1:46Neil deGrasse Tyson?

  Thanks for all you bring to StarTalk.

• 1:48Charles Liu?

  Always happy to be here, happy to see you guys.

• 1:50Neil deGrasse Tyson?

  And you're still our Geek in Chief?

• 1:52Charles Liu?

  Thank you.

• 1:52Neil deGrasse Tyson?

  And you are the evidence that the geek spectrum is infinite in all directions. Because however geeky I am... One need not be impressed by that when they see the geekier person than me. Okay? So.

• 2:07Charles Liu?

  I would not presume. But thank you so much. It's very kind. Really had to be here.

• 2:12Neil deGrasse Tyson?

  So you guys got the questions from our Patreon?

• 2:14Gary O'Reilly?

  We do. Alright, I'll kick us off.

• 2:16Neil deGrasse Tyson?

  Alright, let's do that, Gary.

• 2:17Gary O'Reilly?

  These are exclusive questions from our Patreon contributors, so thank you very much.

• 2:21Neil deGrasse Tyson?

  Yes.

• 2:21Gary O'Reilly?

  Go on, you want to jump in?

• 2:22Chuck Nice?

  Here we go. This is Laz, and Laz says, "Hey Neil and Chuck." He's talking about Chuck.

• 2:28Gary O'Reilly?

  Oh, thanks, Chuck.

• 2:29Chuck Nice?

  And he says, "This is Justin from Houston, Texas. I was wondering the other..."

• 2:33Charles Liu?

  Wait, I thought it was Laz.

• 2:34Chuck Nice?

  Well, he goes by Laz.

• 2:36Neil deGrasse Tyson?

  Laz since his handle. Just because his handle don't have to be your name, dude. Get with the century.

• 2:44Charles Liu?

  We're having another nerd fight. Press X to die.

• 2:48Chuck Nice?

  That was rather aggressive.

• 2:49Neil deGrasse Tyson?

  Yeah, it was a little aggressive.

• 2:52Charles Liu?

  It's alright.

• 2:53Chuck Nice?

  He says, "I was wondering the other week, if gravity affects the flow of time and black holes are concentrated gravity, would the age of the universe be different based on the size of your nearest black hole? Side question: If I were to make a theoretical cloak of black holes around my body, would time cease to exist for me, or would it change the rate of time inside the cloak at all?"

• 3:20Charles Liu?

  Wow.

• 3:20Chuck Nice?

  Yeah.

• 3:21Neil deGrasse Tyson?

  Cloak, he's feeling Harry Potter there.

• 3:23Chuck Nice?

  He really is. The invisibility cloak of Harry Potter.

• 3:26Neil deGrasse Tyson?

  But it's a time cloak.

• 3:27Chuck Nice?

  It's a time cloak, right?

• 3:30Charles Liu?

  Yes. The, to answer the cloak question first, you can't make a cloak of theoretical black holes, because you create basically one big black hole as a result.

• 3:44Chuck Nice?

  Right.

• 3:45Charles Liu?

  In the stuff on the inside, time could stand still, but you've created essentially an event horizon around the interior of this cloak. So.

• 3:56Charles Liu?

  Time could stand still for you if you were keeping time still at that point.

• 4:00Chuck Nice?

  So could you, could you make like a Lagrange point of black holes? Where all the black holes are in a stable little, you know, environment? And each event horizon is touching just enough where it doesn't tug? And then you're just perfectly perched right in that middle of that?

• 4:21Charles Liu?

  That is not-

• 4:22Neil deGrasse Tyson?

  Listen to him talking about Lagrange points.

• 4:24Charles Liu?

  It's great. It's wonderful. No, this is a very serious and valuable question. In fact-

• 4:29Chuck Nice?

  I learned it from watching you!

• 4:33Charles Liu?

  That was from that wonderful drug commercial. Kids, yeah.

• 4:37Chuck Nice?

  The kid, he was like, "You're doing drugs. Where'd you learn this?" And he says to his dad, "I learned it from watching you, okay?"

• 4:44Charles Liu?

  Parents who do drugs have kids-

• 4:47Chuck Nice?

  Have kids who do drugs.

• 4:49Charles Liu?

  Yes.

• 4:50Neil deGrasse Tyson?

  Go ahead. Did you guys grow up together? I don't remember any of these personal things.

• 4:54Chuck Nice?

  Okay, all right, go ahead.

• 4:56Gary O'Reilly?

  There's no way I could have done that.

• 4:57Neil deGrasse Tyson?

  Yeah, yeah, just stay out of that one.

• 5:02Charles Liu?

  You cannot put black holes just so they barely touch by event horizon and keep them stable. They, the quantum mechanical effects, gravitational radiation will inevitably cause them to crash into one another.

• 5:14Chuck Nice?

  Okay.

• 5:14Charles Liu?

  Because they're not that way. However, Boden Pachinsky, who is an astronomer from a long, long time ago, or maybe Andrej Pachlich, one of those two guys, maybe decades ago, suggested that the centers of galaxies might contain configurations of black holes that were indeed kind of buzzing around a common center of gravity like bees swarming around. Now, the problem in the end is going to be the gravitational radiation that comes from that. They will eventually collapse. If they're that close, they just can't stay in a stable configuration purely gravitationally. They need something else to keep them apart. Otherwise, they coalesce, they release gravitational waves. We see it at LIGO and we can find out what-

• 5:55Neil deGrasse Tyson?

  Yeah, but we don't have to be that exotic. Just put them on a planet orbiting very close to the black hole, as we saw in the film- Interstellar, if you're really close to a black hole, your time takes way more slowly than everybody else. So is that all you need to solve his question?

• 6:12Charles Liu?

  Well, yeah. If you get close to the black hole, time for you runs more slowly, but the rest of the universe...

• 6:19Neil deGrasse Tyson?

  We see your time runs slower. No, time for you runs normal.

• 6:22Charles Liu?

  Yeah. For me, what I felt like was a second or two. It doesn't change anything, but you guys see me, right? Having only been one second, well, you guys experience decades of life or something like that. So, that particular question is hard to answer specifically that way, but the answer is, like you said, we solve the problem.

• 6:42Neil deGrasse Tyson?

  In fact, the New York Times science journalist from the 60s and 70s, Walter Sullivan, wrote a book called Frozen Star, back in the early days of black holes, where if you see someone about to fall in, they're basically frozen relative to you.

• 6:56Charles Liu?

  Right.

• 6:57Neil deGrasse Tyson?

  You'll just see them just sort of pause.

• 7:00Charles Liu?

  Yeah, and that was used in, that's been used in a number of places. There was a TV show called Andromeda starring Kevin Sorbo, where he in fact was in the ship and was caught almost falling in. And during that moment where he's kind of caught, he didn't age at all, but other people did. And 300 years later, using more advanced technology, someone salvages his ship. And so now he's like fish out of water, guy who's 300 years older than everybody else, and somehow he still can save the universe.

• 7:31Chuck Nice?

  So the first part of this question, which was, if gravity affects the flow of time, are black holes concentrated gravity? So, so is a black hole, is the gravitational effects of a black hole the result of the black hole, its density? Or is it actually gravity itself concentrated?

• 7:57Charles Liu?

  Well, gravity, Neil, tell me if I'm explaining this okay, is essentially the curvature of spacetime caused by mass.

• 8:05Neil deGrasse Tyson?

  Mm-hmm.

• 8:05Charles Liu?

  Okay?

• 8:06Neil deGrasse Tyson?

  That's an energy.

• 8:06Charles Liu?

  Yeah, and mass and energy. So if... A black hole is sitting there. We don't necessarily think of it as a concentrated point of gravity, but rather as an object that happens to warp space and time so significantly that it has an event horizon around it. So to answer that question, I think, is to express it differently.

• 8:30Neil deGrasse Tyson?

  Yeah, I don't know if it's semantic at that level.

• 8:31Charles Liu?

  Yeah.

• 8:32Neil deGrasse Tyson?

  Because Einstein, after Einstein, Newton was, there's an object and there's a gravitational field.

• 8:39Charles Liu?

  Okay.

• 8:40Neil deGrasse Tyson?

  All right. Einstein is, there's an object and spacetime is warped in the presence of that object. And everything you do and how you move is influenced by this curvature of spacetime. And you measure that curvature to be gravity.

• 8:56Charles Liu?

  Yeah, right.

• 8:57Neil deGrasse Tyson?

  So that's, it turns out that might sound semantic, but that Einsteinian description is way more accurate in predicting phenomenon in the universe.

• 9:07Charles Liu?

  Right.

• 9:08Neil deGrasse Tyson?

  And so, but to quibble over what happens to the time.

• 9:12Charles Liu?

  Right.

• 9:13Neil deGrasse Tyson?

  Yes, time slows down for you. After that, I don't know what more interesting there is to talk about.

• 9:18Charles Liu?

  And there's a, of course, one of the most important parts of the general theory of relativity is the equivalence principle, which means that at some point you can't tell the difference between the curvature of spacetime causing you to move differently and some sort of acceleration that's causing you to move differently. So as far as the time changing and differing, I think Neil has the right idea on this one.

• 9:42Neil deGrasse Tyson?

  Charles, aren't all parts of the general theory of relativity important?

• 9:47Charles Liu?

  Yes. But some parts are more important, too.

• 10:06Speaker 04

  Hello, I'm Vicky Brook Allen, and I support StarTalk on Patreon. This is StarTalk with Neil Gras Tyson.

• 10:23Neil deGrasse Tyson?

  All right, who's next up?

• 10:25Gary O'Reilly?

  All right, um, Bill Bailey. Hi, Bill. Says, uh, Guardians of the Galactic Groove. That'll be...

• 10:33Neil deGrasse Tyson?

  Okay.

• 10:34Gary O'Reilly?

  You too, you too, Gary. I'm an innocent bystander. Say I fall into a black hole. I cross the event horizon if, and we're back to Kevin Sorbo. If there really was a singularity in my future, not a point in space, would it take me till the end of time to reach it? Are you of the opinion that black holes are really places as opposed to objects? And Bill Bailey hails from Ohio, so here we go.

• 10:57Charles Liu?

  Yeah. Are black holes places or objects? Black holes are definitely objects. They can move through space and time.

• 11:04Gary O'Reilly?

  Right.

• 11:05Chuck Nice?

  They can collide, so clearly...

• 11:07Charles Liu?

  So they are objects.

• 11:08Chuck Nice?

  Clearly, they are.

• 11:09Charles Liu?

  But the singularity that Bill is describing would be a place. Possibly a place inside the black hole. Because singularities might not even have to exist. As long as something is inside an event horizon, we actually don't know how the material is structured inside it. So when you're falling, Bill, you actually are falling in toward the event horizon. You don't know if there's a singularity there. And in fact, it would take you a huge amount of time, possibly an infinite amount of time, to fall into the black hole as you. Because what happens is that the black hole's event horizon grows to meet you. And as you look in toward the event horizon, the things closer to the event horizon to you,

• 11:53Charles Liu?

  you see their time going more slowly. But if you look backwards, then the time is going more fast or quickly in the other direction. So at the moment you are reaching the black hole's event horizon, you see the entire history of the entire universe of that location simultaneously.

• 12:14Neil deGrasse Tyson?

  Entire future history of the universe behind you. unfolding, right? Because you've slowed down...

• 12:21Gary O'Reilly?

  And the entire past.

• 12:22Neil deGrasse Tyson?

  And the entire...

• 12:22Chuck Nice?

  Because time has basically stopped for you.

• 12:24Gary O'Reilly?

  Yeah.

• 12:24Chuck Nice?

  That's so...

• 12:27Chuck Nice?

  I'm crazy! It's insane!

• 12:31Neil deGrasse Tyson?

  The universe is under no obligation to make sense to me.

• 12:35Chuck Nice?

  Well, it succeeded. It certainly succeeded. That is insane!

• 12:42Charles Liu?

  In these big, huge concepts that we're talking about here, about quantum versus general relativity versus space and time, it sometimes can be helpful to think of time as always existing, past, present, and future, and you're just filling in that dimension as you happen to pass through it.

• 13:02Neil deGrasse Tyson?

  We are prisoners of the present, forever transitioning between our inaccessible past and our unknowable future.

• 13:10Chuck Nice?

  Oh, that's in the Bible.

• 13:15Gary O'Reilly?

  According to Captain Kirk.

• 13:18Charles Liu?

  Prisoners sounds so depressing. Makes me feel like I'm Patrick McGowan or Number Six or something like that.

• 13:25Neil deGrasse Tyson?

  Wait, don't put emotion in what I just said. It just is.

• 13:28Charles Liu?

  Maybe we're not prisoners. Maybe we're privileged participants in the present.

• 13:33Chuck Nice?

  Ooh, that sounded like a creepy prisoner to me.

• 13:37Chuck Nice?

  Don't worry, one day you'll be able to leave the basement.

• 13:41Neil deGrasse Tyson?

  But not now.

• 13:42Chuck Nice?

  Not now!

• 13:43Neil deGrasse Tyson?

  Not today.

• 13:45Charles Liu?

  What do we say to the gods of prison?

• 13:47Neil deGrasse Tyson?

  By the way, that me uttering that line was lifted by Beyonce for her international tour between songs.

• 13:54Chuck Nice?

  Are you serious?

• 13:55Gary O'Reilly?

  Absolutely! Alright, so who is the author of that particular quote?

• 13:59Chuck Nice?

  That's him, man!

• 14:00Neil deGrasse Tyson?

  It would be me.

• 14:01Chuck Nice?

  That's him!

• 14:02Gary O'Reilly?

  Thank you. I didn't know that before, that's why I am.

• 14:04Neil deGrasse Tyson?

  Oh, you didn't know? Okay.

• 14:05Gary O'Reilly?

  No sarcasm.

• 14:06Neil deGrasse Tyson?

  Yeah, well, that's okay.

• 14:08Chuck Nice?

  So wait a minute, okay, now I'm derailing the show. But I gotta derail the show, I'm sorry!

• 14:12Neil deGrasse Tyson?

  Because somebody mentioned Beyonce.

• 14:14Chuck Nice?

  Yes, exactly! Please, are you kidding me? Stay focused, come on. We can't stay... Come on, you mentioned Beyonce. I mean, it's a law. Whenever somebody mentions Beyonce, all things must stop, and we gotta talk about Beyonce now.

• 14:26Charles Liu?

  Beyonce did do one of the greatest videos of all time.

• 14:28Chuck Nice?

  Which was?

• 14:29Charles Liu?

  Of all time!

• 14:30Chuck Nice?

  Of all ti... Oh, that's right. I'm gonna let you finish.

• 14:33Charles Liu?

  I'm gonna let you finish.

• 14:34Chuck Nice?

  Okay.

• 14:36Chuck Nice?

  Okay, please.

• 14:38Neil deGrasse Tyson?

  What, what?

• 14:38Chuck Nice?

  What did Beyonce, how did Beyonce get this quote?

• 14:43Neil deGrasse Tyson?

  I'm on the internet somewhere saying it. And her people, or she, saw it, said, "That's cool."

• 14:50Chuck Nice?

  No, but what I'm saying is, did they use your voice?

• 14:53Neil deGrasse Tyson?

  Yes.

• 14:53Chuck Nice?

  Okay, that's different.

• 14:54Charles Liu?

  Did she violate your copyright?

• 14:55Chuck Nice?

  So here's what I'm thinking.

• 14:57Neil deGrasse Tyson?

  Yeah.

• 14:57Chuck Nice?

  Okay, I'm thinking, it's like, you know, "Got me looking so crazy right now, thank you." We are all prisoners. Like, that's how I thought it went down.

• 15:07Neil deGrasse Tyson?

  Yeah.

• 15:08Chuck Nice?

  But it's you, it's actually you saying it.

• 15:09Neil deGrasse Tyson?

  It's my voice.

• 15:10Chuck Nice?

  Okay, that's cool. "We are just prisoners here..."

• 15:13Neil deGrasse Tyson?

  Yeah.

• 15:13Chuck Nice?

  "...of our own life." Okay, that was, I, I thought-

• 15:16Neil deGrasse Tyson?

  It wasn't for the domain, it was for the international tour.

• 15:18Chuck Nice?

  Okay, but I thought she was quoting you, but really, they were using you as a part of the actual-

• 15:23Neil deGrasse Tyson?

  That's correct.

• 15:24Chuck Nice?

  Concert.

• 15:24Neil deGrasse Tyson?

  Yeah.

• 15:25Gary O'Reilly?

  That's still cool, that's really cool. That's, you know, we get back on the road, I mean.

• 15:29Neil deGrasse Tyson?

  Oh, and, people ask me, "Well, how much did they pay you?" So I told them how much, and they say, "Dude, you should have gotten Beyonce tickets, it would have worked much better."

• 15:38Neil deGrasse Tyson?

  It was like, no, but I'm not, I-

• 15:39Chuck Nice?

  Now we gotta get you in a Taylor Swift concert.

• 15:44Neil deGrasse Tyson?

  All right, who's next?

• 15:45Gary O'Reilly?

  You wanna go, or I'll go?

• 15:46Chuck Nice?

  No, you go.

• 15:46Gary O'Reilly?

  All right.

• 15:47Neil deGrasse Tyson?

  Why are these all about black holes?

• 15:49Chuck Nice?

  These are all about black holes in the beginning?

• 15:50Neil deGrasse Tyson?

  Well, I should have said that at the, at the top.

• 15:52Chuck Nice?

  Oh, no, not everything's a-

• 15:54Neil deGrasse Tyson?

  Okay, okay, go.

• 15:54Gary O'Reilly?

  All right, so, this one's from Matthew, again, these are all Patreon patrons that are contributing these questions, so thank you very much. I, Neil, Charles and Chuck, Matthew from Dallas, that'll be in Texas. Um, "Is there a way to transfer information?"

• 16:08Neil deGrasse Tyson?

  You said Dallas, Norway, yes.

• 16:10Gary O'Reilly?

  Yeah, no, but it just, it actually says Dallas TX, so I'm just, just in case, it's like a Paris, Texas, as opposed to Paris, France.

• 16:15Neil deGrasse Tyson?

  This is America, dude, we know where Dallas is.

• 16:18Gary O'Reilly?

  Do we? We're so happy for you.

• 16:22Charles Liu?

  It's just south of Amarillo, right?

• 16:24Gary O'Reilly?

  Oh, here we go, you're back on it. "Is there a way to transfer information?" He's giggling. "Is there a way to transfer information with quantum entanglement? If so, can we instantaneous communication anywhere in the universe, no subspace required?"

• 16:40Charles Liu?

  At the moment, quantum entanglement could provide instantaneous information transfer, but we haven't been able to confirm it. There's no way yet for us to be able to conduct experiment that can show that quantum entangled particles could travel, transfer information faster than light. There's nothing mathematical says that it can't, but there's nothing physical that says that it can.

• 17:05Neil deGrasse Tyson?

  Okay, so he says no subspace required. Okay. What is subspace? Is there a subspace?

• 17:14Charles Liu?

  Subspace.

• 17:14Neil deGrasse Tyson?

  Are you really asking that? I'm saying, have you been my, you, you, you asking that?

• 17:18Gary O'Reilly?

  I think Chuck's asking it on behalf of our audience.

• 17:21Neil deGrasse Tyson?

  I am asking on behalf.

• 17:23Charles Liu?

  Let's not be harsh on Chuck. Subspace is an important question.

• 17:26Neil deGrasse Tyson?

  Okay, so subspace, Chuck.

• 17:27Charles Liu?

  Subspace was invented by Star Trek writers.

• 17:31Neil deGrasse Tyson?

  Yes.

• 17:31Charles Liu?

  Because it needed to find a way to move things faster than light from one point to another in our universe. And so.

• 17:38Neil deGrasse Tyson?

  Not just things, but communication.

• 17:39Charles Liu?

  Yes, subspace communications are even more amazing than, than actual traveling through subspace. But what you do is your warp nacelles create a warp bubble around you, which puts you out of our universe and into subspace, which then allows you to squirt forward like a little bubble through spacetime at faster than light. So warp 10 is an infinite speed. And you get, it's a logarithmic scale. Warp 9 and warp 9.9 and warp 9.99 and so on and so on. Just gets you faster and faster and faster.

• 18:12Neil deGrasse Tyson?

  That's where the engines really can't take it.

• 18:13Charles Liu?

  That's right.

• 18:14Gary O'Reilly?

  She's breaking up, Captain.

• 18:16Chuck Nice?

  She's breaking up. She can't take it, Captain. I can't do anymore.

• 18:21Charles Liu?

  The USS Voyager.

• 18:26Neil deGrasse Tyson?

  Scotty and Shrek were the same.

• 18:28Chuck Nice?

  Scotty and Shrek were the same, you know.

• 18:30Charles Liu?

  The Star Trek Enterprise D could go around, could go around warp 9.4 at a sustained period of time. But Star Trek Voyager had 17 decks and had a nominal cruising speed of warp 9.975. So it was a speedy little ship.

• 18:47Neil deGrasse Tyson?

  Okay, so subspace allows, because with, with regard to communication, if they're just having banter with, with, you know, home base, what the.

• 18:58Charles Liu?

  Starbase, Starfleet.

• 18:59Neil deGrasse Tyson?

  Yeah, Starfleet Command.

• 19:00Charles Liu?

  San Francisco.

• 19:01Neil deGrasse Tyson?

  Starfleet Command. If they're just having conversation back and forth, that's not really possible.

• 19:06Charles Liu?

  Right.

• 19:07Neil deGrasse Tyson?

  If it's moving at the speed of light.

• 19:08Charles Liu?

  That's right. So all those conversations in Star Trek, or through really any space show, had to be going through some medium other than regular space.

• 19:17Chuck Nice?

  Right.

• 19:18Gary O'Reilly?

  We're nowhere near that right now, are we?

• 19:20Charles Liu?

  Not anywhere.

• 19:21Gary O'Reilly?

  Absolutely nowhere. Okay.

• 19:23Charles Liu?

  It'd be nice.

• 19:24Chuck Nice?

  All right, this is Wendy Sue, and Wendy says, "Hi, Dr. Tyson, Dr. Lou, Mr. Nice, the glue that holds everything together in... I'm from Shanghai, China. I didn't know Shanghai, China was the glue that holds everything together."

• 19:38Charles Liu?

  Oh, right.

• 19:39Gary O'Reilly?

  Which you.

• 19:40Chuck Nice?

  Uh, if gravity is the curvature of spacetime, say if two celestial objects were to stay completely still relative to each other, they would feel zero effect from each other's gravity, because they are not moving through the fabrics. Thanks for bringing back the joys of learning. Okay, uh, I, I don't think, uh... I missed the question. If gravity is the curvature of spacetime, say if two celestial objects were to stay completely relative to each other, uh, they would feel zero effect from each other's gravity.

• 20:16Charles Liu?

  They would. They would.

• 20:18Chuck Nice?

  I, I guess the question is, is that the case? Is this the case?

• 20:21Charles Liu?

  It turns out that, no, they would still feel the effects. You see, because gravity, say you have object A, it has a gravitational field that distorts spacetime around it. Object B is over here, it distorts spacetime around it. Even if they're still with one another, they still feel the distortions. The distortions do not change with time if they're exactly a far apart, but they still feel each other. So they may not accelerate toward each other, but they feel that force. They should accelerate toward each other if no other forces or accelerations are present. That would have to be the case if the two of them are staying absolutely still with respect to one another. And the only way that they would not feel each other's gravity is if they didn't have any gravity at all.

• 21:02Neil deGrasse Tyson?

  I will, I will quote John Archibald Wheeler.

• 21:05Gary O'Reilly?

  Will you?

• 21:07Neil deGrasse Tyson?

  He's dead.

• 21:09Chuck Nice?

  He's dead, Gary. Is it final?

• 21:13Gary O'Reilly?

  Go on.

• 21:14Neil deGrasse Tyson?

  Mass tells space how to curve?

• 21:18Neil deGrasse Tyson?

  Space tells mass how to move.

• 21:21Chuck Nice?

  Ooh.

• 21:22Neil deGrasse Tyson?

  Okay, so in this case, we have two objects that have curved spacetime in their vicinity. Those, that's all the instructions they need to fall towards one another or towards each other.

• 21:36Charles Liu?

  That's right.

• 21:37Neil deGrasse Tyson?

  And because they're following the path that they can't help following.

• 21:43Charles Liu?

  Right.

• 21:43Chuck Nice?

  Celestial dust. I love how specific how you differentiate one another from each other.

• 21:49Neil deGrasse Tyson?

  Oh, yeah.

• 21:50Chuck Nice?

  I caught that. I caught that.

• 21:51Neil deGrasse Tyson?

  So I had to correct the grammar.

• 21:52Chuck Nice?

  Yeah, yeah, yeah.

• 21:53Neil deGrasse Tyson?

  Yeah, each other is just between two people.

• 21:55Chuck Nice?

  Two people, right.

• 21:56Charles Liu?

  Right, so if they're staying.

• 21:58Neil deGrasse Tyson?

  Your mama, I was gonna make your mama proud.

• 22:00Chuck Nice?

  Yeah.

• 22:01Neil deGrasse Tyson?

  She taught English, right?

• 22:02Chuck Nice?

  Well, no, and I was the one who said it incorrectly, so she's proud of you.

• 22:10Charles Liu?

  Right, so if they're perfectly still with respect to one another, they are experiencing something else that's keeping them perfectly still with respect to one another.

• 22:19Chuck Nice?

  Ahah.

• 22:19Charles Liu?

  Otherwise, they would be accelerating towards one another.

• 22:22Chuck Nice?

  They would move towards each other.

• 22:22Neil deGrasse Tyson?

  I have an addendum to this, if I may.

• 22:24Charles Liu?

  Please.

• 22:25Neil deGrasse Tyson?

  One of the most realistic scenarios to deflect an asteroid that might be headed our way is to take a spaceship, park it near the asteroid in perfect path with it. So I tell park it mean, it's a moving asteroid.

• 22:39Chuck Nice?

  It's a moving asteroid, so it's just moving alongside of it.

• 22:41Neil deGrasse Tyson?

  So you park it, so it moves alongside of it, and they want to move towards each other.

• 22:47Chuck Nice?

  Yeah.

• 22:48Neil deGrasse Tyson?

  But you have little retro-rockets on your spacecraft that prevent that.

• 22:52Chuck Nice?

  So every time it tries to move towards.

• 22:55Neil deGrasse Tyson?

  Okay.

• 22:56Chuck Nice?

  The retro-rockets fire.

• 22:58Neil deGrasse Tyson?

  Fire.

• 22:58Chuck Nice?

  And it's just like, I'm, I'm just gonna move over here.

• 23:01Neil deGrasse Tyson?

  Over here, but I still want you.

• 23:02Chuck Nice?

  And it's like, where you going, baby?

• 23:03Neil deGrasse Tyson?

  So, so, so, so. So, so the, the meteor, the asteroid, the comet ends up getting pulled towards the spaceship through the gravitational field. So in a way, it's like a gravitational tractor beam.

• 23:17Chuck Nice?

  Right. Don't stand so close. Very nice.

• 23:22Gary O'Reilly?

  So you don't need much of a deflection.

• 23:24Neil deGrasse Tyson?

  If you get it early enough, tiny deflections is all you need.

• 23:27Chuck Nice?

  Right.

• 23:28Neil deGrasse Tyson?

  Oh, yeah.

• 23:29Gary O'Reilly?

  All right, right.

• 23:30Neil deGrasse Tyson?

  Oh, and that also has the benefit that some asteroids, comets, we think they're not very tightly held together. Some might be just piles of rubble, moving as in unison. Whereas if you just have a, if you just go in and bust it up, who knows what that's gonna look like. But gravitationally, that'll affect all the particles together. And so you're good.

• 23:50Gary O'Reilly?

  Okay.

• 23:51Neil deGrasse Tyson?

  Yeah.

• 23:52Gary O'Reilly?

  Two in one. All right, this question, next question is Javier Ortega. Hi, I'm an. Javier?

• 23:59Neil deGrasse Tyson?

  Javier.

• 24:00Gary O'Reilly?

  Javier, Javier Ortega. I'm an engineer from Panama. Here goes my.

• 24:05Chuck Nice?

  Panama. Bam, bam, bam, bam.

• 24:08Gary O'Reilly?

  Panama.

• 24:10Chuck Nice?

  Wow.

• 24:11Neil deGrasse Tyson?

  Okay.

• 24:12Chuck Nice?

  Very nice.

• 24:12Charles Liu?

  The spirit moved me.

• 24:13Gary O'Reilly?

  I know, and it's great. Okay, the question is, the light of the stars travels away from it in an infinitely dense sphere of photons. Will every unobstructed object in the distance receive its photons? How can this be if in the far distance, the rays will spread apart from the star? I know we can be talking about quantum waves instead of photons, but even in that case, I can't figure how this light can maintain its density through the distance and size. Greetings from the past. Love your show. You're welcome.

• 24:47Charles Liu?

  I think I understand the question.

• 24:49Neil deGrasse Tyson?

  That's a really good question.

• 24:50Charles Liu?

  Imagine a star, right? And the rays come in every direction.

• 24:54Chuck Nice?

  Right.

• 24:55Charles Liu?

  So those rays start spreading farther and farther apart so that they'll not intersect some stars, whereas they will intersect others. Right?

• 25:03Neil deGrasse Tyson?

  Yeah, does every single sightline onto a star from every single distance receive light? And how could the star be giving off that much light?

• 25:13Chuck Nice?

  Right.

• 25:13Neil deGrasse Tyson?

  That's a great question.

• 25:14Chuck Nice?

  That's a great question, but how could it not? I mean, that, seriously, I mean, because no matter where you are and whatever vantage point, you would see light.

• 25:24Neil deGrasse Tyson?

  Here's what I want to try.

• 25:25Chuck Nice?

  Oh, I'm sorry, Charles.

• 25:26Neil deGrasse Tyson?

  Check me out on this.

• 25:26Chuck Nice?

  Okay.

• 25:27Neil deGrasse Tyson?

  Okay? I'm thinking just in real time, because I didn't have the answer ready-made for this.

• 25:31Gary O'Reilly?

  No, no.

• 25:31Neil deGrasse Tyson?

  Here's what I want.

• 25:32Gary O'Reilly?

  That's the whole idea of this.

• 25:33Neil deGrasse Tyson?

  Here's what I wonder.

• 25:35Neil deGrasse Tyson?

  As your distance gets greater and greater from the star, the energy density of the light diminishes.

• 25:43Charles Liu?

  Correct.

• 25:44Chuck Nice?

  Yep.

• 25:44Neil deGrasse Tyson?

  Okay. So the intensity drops and drops and drops and drops. And so there will be a point where it's below your ability to detect it. Maybe that's this point in practice.

• 25:59Charles Liu?

  That's right.

• 25:59Neil deGrasse Tyson?

  For what it is you're talking about.

• 26:01Charles Liu?

  In practice, there is a detection threshold. And therefore.

• 26:06Neil deGrasse Tyson?

  For any detector.

• 26:06Charles Liu?

  For any detector.

• 26:07Neil deGrasse Tyson?

  Yes.

• 26:07Charles Liu?

  So that might as well.

• 26:08Neil deGrasse Tyson?

  Any real world.

• 26:09Charles Liu?

  In mathematical reality, you actually can, in fact, eventually receive light from every single object in the universe. This is the basis of Olber's paradox. Why is the sky dark at night? If there are enough stars out there, every line of sight should get some light from it somehow. And you eventually wind up filling the entire night sky with stars or starlight, one way or another, no matter what. So why is a star? Why is the sky ever dark? And part of the answer, one way to think of the answer, is that light travels at a finite speed. And therefore, not every spot actually has a light source where the light has had time to reach your eye yet.

• 26:55Charles Liu?

  Another point has to do with.

• 26:57Neil deGrasse Tyson?

  An object can be so far away. In the time it has turned on.

• 27:02Charles Liu?

  It's light.

• 27:02Neil deGrasse Tyson?

  There's not enough time in the universe.

• 27:04Chuck Nice?

  To reach.

• 27:04Neil deGrasse Tyson?

  That's one of three ways.

• 27:06Charles Liu?

  Yeah, there are different ways out of this thing. But that's one way that you can think about it, right? In other ways, this detection limit, your eyes can't see them even though it's there, right? Right now, one of the famous things that we do in a science is to try to find cosmic background radiation, right? Microwave radiation is famous from the Big Bang, but also there's cosmic infrared radiation background. There's cosmic visible light background. Like, exactly how much is it? Spaces that we looked years ago that were completely blank, had nothing in there. We stare at it with the Hubble Space Telescope or JWST, and thousands of galaxies appear. It's all a matter of detection. So hopefully that answers the question there. And if we're talking about like the light from the Big Bang, where.

• 27:51Charles Liu?

  The entire universe is being filled with all of this light that existed at the moment that the universe began. What's going on there is that the entire spectrum of that background light is being stretched as space is expanding. So that's why that light, which used to be gamma rays, is now microwaves. And so you can fill the space.

• 28:12Neil deGrasse Tyson?

  A much lower branch of, energy branch of spectrum.

• 28:14Charles Liu?

  So you can fill the space with the same amount of energy, just each spot in space has much less of it.

• 28:21Neil deGrasse Tyson?

  Wow.

• 28:23Chuck Nice?

  So there you go.

• 28:24Neil deGrasse Tyson?

  Deep, significant question.

• 28:25Charles Liu?

  Yeah. Some great questions.

• 28:26Chuck Nice?

  People have been on point today, man.

• 28:56Neil deGrasse Tyson?

  Guys, we've got only like five minutes left. Okay. Oh, man. So, Charles, you and I have to tighten our game here, okay? Charles, you pulled out your stopwatch. What's that?

• 29:04Chuck Nice?

  Uh, so I figure if we gotta get through these quickly, then we'll just do a time limit on each question.

• 29:11Neil deGrasse Tyson?

  Okay.

• 29:11Chuck Nice?

  And then you guys have to determine whether or not you can answer it in that.

• 29:16Neil deGrasse Tyson?

  Okay.

• 29:16Chuck Nice?

  So, what do we say? Thirty seconds? I think that's a good round number.

• 29:21Neil deGrasse Tyson?

  All right. Thirty? That's a, that's soundbite.

• 29:23Chuck Nice?

  That's a long time.

• 29:24Neil deGrasse Tyson?

  Even news finds you on the street. Make it ten. Ten seconds?

• 29:27Chuck Nice?

  No, that's too much. That's too short.

• 29:30Neil deGrasse Tyson?

  You're the Usain Bolt of science.

• 29:31Chuck Nice?

  You don't have to use the whole thirty seconds. I'm just saying that the most of it can be.

• 29:35Neil deGrasse Tyson?

  If you can do it in ten, do it in ten.

• 29:36Chuck Nice?

  If you can do it in ten, do it in ten. But thirty seconds, time is up.

• 29:38Neil deGrasse Tyson?

  Let's go.

• 29:39Chuck Nice?

  Okay?

• 29:39Neil deGrasse Tyson?

  All right.

• 29:40Chuck Nice?

  So how about?

• 29:40Neil deGrasse Tyson?

  I don't want to take five minutes explaining why we're only gonna take.

• 29:43Chuck Nice?

  Exactly.

• 29:43Neil deGrasse Tyson?

  Ten seconds.

• 29:44Chuck Nice?

  All right, here we go.

• 29:44Neil deGrasse Tyson?

  Go.

• 29:45Chuck Nice?

  This is Jamie Wilson. Greetings, Dr. Tyson and honored guest, Charles Liu. If you could time travel to any point in human scientific history, which time period would you choose and why? Jasmine from Santa Rosa, California.

• 29:54Neil deGrasse Tyson?

  Go. Whoa. Trinity. First nuclear explosion. I would time travel back to the collision of Theia and Earth, which made the moon. I want to see that in the, in the night sky.

• 30:06Chuck Nice?

  Dang. I would time travel forward to a place where black people are doing okay.

• 30:17Neil deGrasse Tyson?

  All right, so Thea would be now four and a half billion years ago.

• 30:22Gary O'Reilly?

  Right.

• 30:22Neil deGrasse Tyson?

  And Trinity would now be 70 years ago, 80 years ago.

• 30:25Charles Liu?

  1945.

• 30:25Neil deGrasse Tyson?

  Yeah, okay.

• 30:26Gary O'Reilly?

  Okay. All right, next question, Frederick Deschamps. Fred's from UP Michigan and would like to know if you, Charles, have read the Discworld books?

• 30:34Charles Liu?

  Ah, yes, by Terry Pratchett.

• 30:36Gary O'Reilly?

  Yes, indeed. What kind of fun physics can you think of taking place on a magical land such as?

• 30:42Neil deGrasse Tyson?

  And you also, did he also ask for Easter eggs that we might have missed?

• 30:46Gary O'Reilly?

  No, he said there's Sons of Physics Easter eggs in it.

• 30:49Charles Liu?

  Terry tells all kinds of cute physics jokes because this world is literally a disk, but it sits on elephants and then there's a turtle that the elephants are standing on and it just kind of swims through the universe. So it's a...

• 31:02Neil deGrasse Tyson?

  So it's not turtles all the way down?

• 31:03Charles Liu?

  Right.

• 31:04Neil deGrasse Tyson?

  It's just turtles one layer deep?

• 31:05Charles Liu?

  Yes.

• 31:05Neil deGrasse Tyson?

  Okay.

• 31:05Charles Liu?

  So it's almost like a giant disk-shaped spaceship that's going through the universe.

• 31:11Gary O'Reilly?

  That's what it is.

• 31:12Charles Liu?

  And, and it... Yeah, are you guys feeling any Flat Earth trauma going on here?

• 31:17Gary O'Reilly?

  It is.

• 31:18Charles Liu?

  This is rough, yeah.

• 31:19Neil deGrasse Tyson?

  Disguised as...

• 31:19Charles Liu?

  But Terry was one of those folks that always told good jokes about science. Yep.

• 31:27Neil deGrasse Tyson?

  I stole five of a second.

• 31:28Charles Liu?

  It's all good, it's all good. Now, his humorous physics Easter eggs were good enough for me. I have yet to speculate, aside from this very good point, that you're basically seeing new constellations all the time.

• 31:40Neil deGrasse Tyson?

  Okay.

• 31:41Gary O'Reilly?

  Ooh.

• 31:42Neil deGrasse Tyson?

  All right.

• 31:42Gary O'Reilly?

  Chuck's monitoring your time. This question's from Logical Hillbilly from wonderful West Virginia. I have a question about white holes. Here we go. Although Einstein's equations show that mathematically they can exist, nothing has been found that fits the description. Is it possible that there was only one white hole and it was as what we know as the Big Bang? Thank you for all the awesome information.

• 32:06Neil deGrasse Tyson?

  Chuck.

• 32:07Charles Liu?

  Alas, now, the white hole idea and what we have seen about the Big Bang are not compatible.

• 32:16Chuck Nice?

  Wow, that only took nine seconds.

• 32:19Charles Liu?

  I told you.

• 32:20Chuck Nice?

  I told you.

• 32:22Neil deGrasse Tyson?

  Wait, let me, let me, will you yield 10 seconds to me?

• 32:25Charles Liu?

  I yield 20 seconds.

• 32:26Chuck Nice?

  Yeah, cuz.

• 32:27Neil deGrasse Tyson?

  Yield 10 seconds to the gentleman from the Bronx. Okay, uh, so when white holes were first put forth, we deeply wanted quasars to be white holes at the edge of the universe. There's a very high concentration of energy coming out of them. And when you compared what you'd predict for a white hole with every known object in the universe, nothing matched. So the white hole remains mathematical speculation. Unfortunately, cuz it'd be a really cool pairing with the universe's black holes.

• 32:54Chuck Nice?

  Yeah.

• 32:55Gary O'Reilly?

  Right.

• 32:56Neil deGrasse Tyson?

  Okay.

• 32:56Gary O'Reilly?

  Okay, hit, ready, set up.

• 32:58Chuck Nice?

  That wasn't 20 seconds, so.

• 33:00Gary O'Reilly?

  Yeah.

• 33:00Chuck Nice?

  We, we, we, we made it under 30 seconds.

• 33:03Gary O'Reilly?

  Okay. Chase Matthews, writing from Ventura, California. Do we have the capability of creating a Dyson swarm with technology available today, or maybe a similar structure in low Earth orbit? Dyson swarm, explain, please.

• 33:18Chuck Nice?

  It's a bunch of vacuums that you put the Dyson swarm.

• 33:21Gary O'Reilly?

  I set them up, you knock them down.

• 33:24Neil deGrasse Tyson?

  Uh, I don't know what a Dyson swarm is. I just know what a Dyson sphere is.

• 33:27Charles Liu?

  Yeah, imagine just a whole bunch of satellites that kind of surround a thing.

• 33:32Neil deGrasse Tyson?

  Okay, alright, so it's not a full, solid structure.

• 33:34Charles Liu?

  Yeah, right.

• 33:34Neil deGrasse Tyson?

  Yeah, I mean, a Dyson sphere swarm around Earth would be pointless. The only point of a Dyson sphere is to trap energy coming from the thing in the center of the sphere. So you would put it around the sun. You would put it around the galaxy. You would put it around a galaxy cluster or a cluster of stars. So.

• 33:55Gary O'Reilly?

  Time's up.

• 33:56Charles Liu?

  Yeah, and, and my nine second version.

• 33:59Neil deGrasse Tyson?

  That's actually perfect.

• 34:01Charles Liu?

  And my nine second version is that you can create a constellation like that around the Earth. In fact, some people might be trying to do that, like, say, Starlink or something. But it wouldn't get energy.

• 34:11Neil deGrasse Tyson?

  Yeah.

• 34:12Chuck Nice?

  There you go. You guys did it, I mean.

• 34:15Charles Liu?

  Thank you.

• 34:15Neil deGrasse Tyson?

  Alright.

• 34:16Gary O'Reilly?

  Okay, next question's from Sam Green. I've read that aerogels are heat resistant to extreme temperatures, in some cases 1,300 degrees Celsius.

• 34:25Chuck Nice?

  Wow.

• 34:25Gary O'Reilly?

  Yeah, but are very fragile. Are there any applications or apparatus that could be developed to harness this property to explore the inner Earth or use in nuclear reactors?

• 34:37Chuck Nice?

  Oh, look at that.

• 34:38Neil deGrasse Tyson?

  Oh, well, one application I just learned in the Paris.

• 34:44Neil deGrasse Tyson?

  Fashion Week.

• 34:46Gary O'Reilly?

  Ah.

• 34:46Neil deGrasse Tyson?

  There is a handbag made out of aerogel as a new fashion addition.

• 34:51Gary O'Reilly?

  Do you have one?

• 34:53Neil deGrasse Tyson?

  No, I don't, but I do have my own aerogel on a shelf.

• 34:55Gary O'Reilly?

  Well, of course.

• 34:56Neil deGrasse Tyson?

  Yeah.

• 34:58Neil deGrasse Tyson?

  But what it means is new materials have always influenced the creativity of artists.

• 35:02Gary O'Reilly?

  Yeah.

• 35:02Neil deGrasse Tyson?

  And right up and down, whenever something new happens, creative artists say, hey, I, that's a new material with these properties, I'm gonna do the X, Y, Z with it. So, but in terms of probing Earth, Charles, I don't know how.

• 35:16Charles Liu?

  Aerogels have been used in spacecraft. You basically encase them in something and then that forms a very interesting and useful thermal barrier between something you wanna stay hot and something you wanna stay cold. So you could do that down into the Earth. Problem is with the Earth going into the Earth.

• 35:31Neil deGrasse Tyson?

  In order to visit.

• 35:33Gary O'Reilly?

  Yeah, in Earth.

• 35:33Neil deGrasse Tyson?

  Oh.

• 35:35Charles Liu?

  The pressure is too strong, it will crush the aerogel. Right, and then in a nuclear situation, the radiation will alter the structure of the aerogel unfortunately over time and therefore render it not as effective, so.

• 35:48Neil deGrasse Tyson?

  That's a good point, I hadn't thought of that. So the, its thermal, its thermal properties would be different. There's energy from a thousand degrees Celsius, of course, but targeted particle energy from nuclear reactions would have completely enough energy to break apart all those molecules. So you'd have a pile of dust at the end.

• 36:08Charles Liu?

  Sadly.

• 36:09Neil deGrasse Tyson?

  By my read, yeah.

• 36:10Gary O'Reilly?

  And no handbag.

• 36:11Neil deGrasse Tyson?

  And no handbag.

• 36:14Chuck Nice?

  Last question.

• 36:15Neil deGrasse Tyson?

  Last question, okay.

• 36:16Charles Liu?

  Time flies when you're having fun.

• 36:18Neil deGrasse Tyson?

  Charles and I have been doing okay with the.

• 36:19Chuck Nice?

  I gotta tell you, you, you guys have really been.

• 36:21Neil deGrasse Tyson?

  With the yielding of the time.

• 36:22Chuck Nice?

  You've been knocking it out pretty cool. The last one, um, you, you both did about, I mean, well, Charles was thirty point seven seconds and you were thirty three seconds.

• 36:31Neil deGrasse Tyson?

  Okay.

• 36:32Chuck Nice?

  Which for you was like three and a half seconds.

• 36:34Gary O'Reilly?

  Yeah. If this was a Charles coloring book, you'd just went over the edges.

• 36:38Neil deGrasse Tyson?

  Yeah, okay, yeah, I know, that's a good way to do it.

• 36:40Chuck Nice?

  Who stays in the lines?

• 36:41Gary O'Reilly?

  Anyway, right, Gabe Malik, I'm a high school student from Washington DC, um, I'm writing, what is the most agreed upon geometrical nature of the universe, Euclidean or non-Euclidean? Or is it spherical?

• 36:54Chuck Nice?

  Oh, okay.

• 36:55Charles Liu?

  It's Euclidean.

• 36:57Neil deGrasse Tyson?

  Flat.

• 36:58Charles Liu?

  Absolutely.

• 36:59Neil deGrasse Tyson?

  Flat.

• 36:59Charles Liu?

  It has been confirmed as a consensus almost completely by everyone.

• 37:04Neil deGrasse Tyson?

  Yeah, no one is denying this, and we get that from the dark energy, which flattens out what would otherwise be a spherical shape or a saddle shape. The dark energy flattens that out.

• 37:14Charles Liu?

  That is still a mathematical hypothesis.

• 37:17Neil deGrasse Tyson?

  What is?

• 37:18Charles Liu?

  We have measured the universe to be Euclidean and perfectly flat. And then we think that it is the dark energy that causes it to stay flat, like inflates it just enough, but we don't really know that.

• 37:29Neil deGrasse Tyson?

  What do you think is making it flat?

• 37:30Charles Liu?

  We don't know, but that is one hypothesis.

• 37:33Neil deGrasse Tyson?

  I told you was making it flat.

• 37:34Charles Liu?

  You have to confirm that. There has not yet been an experiment.

• 37:37Neil deGrasse Tyson?

  Is there something else out there that you think could be making it flat?

• 37:40Charles Liu?

  Possibly.

• 37:41Neil deGrasse Tyson?

  Like what?

• 37:42Charles Liu?

  Something called quintessence, which is not exactly dark energy.

• 37:46Gary O'Reilly?

  Sounds like a fragrance.

• 37:47Charles Liu?

  It does. Actually, I think what people have in mind.

• 37:51Gary O'Reilly?

  Quintessence.

• 37:54Charles Liu?

  But the idea is that the geometry...

• 37:56Gary O'Reilly?

  Totally okay. I like it. Quintessence.

• 38:00Neil deGrasse Tyson?

  Yeah, it's...

• 38:00Charles Liu?

  By Cody.

• 38:01Neil deGrasse Tyson?

  Flat.

• 38:02Charles Liu?

  Yeah.

• 38:02Neil deGrasse Tyson?

  Measured flat. And we good.

• 38:05Gary O'Reilly?

  Okay.

• 38:05Charles Liu?

  So, why?

• 38:06Gary O'Reilly?

  There you go, Gabe.

• 38:06Charles Liu?

  We have more left to figure out. There you go.

• 38:09Neil deGrasse Tyson?

  There you go.

• 38:10Gary O'Reilly?

  You're a young person, still in high school, so probably time on your side to work it out.

• 38:13Neil deGrasse Tyson?

  Yeah, I'm working. You figure it out, right.

• 38:16Gary O'Reilly?

  All on you now, Gabe.

• 38:18Neil deGrasse Tyson?

  Charles Lu, delighted to have you back.

• 38:19Charles Liu?

  It is always a pleasure.

• 38:20Neil deGrasse Tyson?

  And we're all here in person, too.

• 38:21Charles Liu?

  I know. What a joy.

• 38:25Charles Liu?

  That's so weird. Oh, so great. Fist bumps and handshakes all around.

• 38:29Neil deGrasse Tyson?

  Fist bump in the middle here.

• 38:30Charles Liu?

  Cosmic queries all the way.

• 38:31Chuck Nice?

  Science powers, activate!

• 38:36Neil deGrasse Tyson?

  Well, that's like a Power Ranger. They all get together and they...

• 38:40Gary O'Reilly?

  The Mousketeers. All for one and one for all.

• 38:43Neil deGrasse Tyson?

  Oh.

• 38:44Gary O'Reilly?

  And the swords rooted in that his...

• 38:47Neil deGrasse Tyson?

  The Mousketeers or the Mousketeers?

• 38:49Gary O'Reilly?

  The Mousketeers came later.

• 38:50Charles Liu?

  Swiggle your ears.

• 38:51Neil deGrasse Tyson?

  I swear he said Mousketeer.

• 38:53Gary O'Reilly?

  I probably did.

• 38:54Neil deGrasse Tyson?

  All right, this has been another installment of StarTalk Cosmic Queries, Grab Bag Edition, Leaning Black Hole, I must say, and Cosmology, but that made it that much sweeter.

• 39:05Charles Liu?

  Black holes don't suck.

• 39:06Neil deGrasse Tyson?

  Black holes don't suck.

• 39:08Gary O'Reilly?

  How long have you waited to say that?

• 39:12Charles Liu?

  But if you fall in one, then that's your new home. Ah. In fact, this was composed by Harry Belafontaine. Black holes don't suck. But if you fall in one, then that's your new home. No, they don't suck, they don't suck, they don't suck, they don't suck. No, they don't. Everyone together. But if you fall in one, then that's your new home.

• 39:42Neil deGrasse Tyson?

  I'm so glad he's dead, right? Oh. So he did not have to hear that? Oh. It is time.

• 39:54Neil deGrasse Tyson?

  Chuck, Gary, Charles, always good to have. Thank you. Being in the same room with you guys. Neil deGrasse Tyson here, as always, bidding you to keep on going.