Cosmic Queries – Planet 9

Introduction

0:00Chuck, another query's grab bag. Yes. My favorite one is the person wants to know what the chance of getting hit by a meteor. Yes. And you were actually taken out by a meteor. Almost. Oh, okay.

0:12Film at 11 on StarTalk.

0:17Welcome to StarTalk. Your place in the universe where science and pop culture collide. StarTalk begins right now.

0:30This is StarTalk Cosmic Queries. And as always, it's a grab bag edition. And I got Chuck Nice with me. How you doing, Chuck? Hey, Neil. Doing well, man. Thanks for asking. There's no shortage of people's questions. Yes. People really inquiring minds want to know. So bring it on. Bring it on. Let's jump right into it.

Andy's Question

0:52Andy L says, hello, stellar intellects and also co-host of the week. My name is, he, he has assumed that the co-host is clearly not of a stellar intellect. So this is.

1:10But he's allowing it to have been other co-hosts because we have other co-hosts. Yes. Come in. Yes. Yes. Yeah. That's why I'm not taking it personally. He says, hey, my name is pronounced Andy. See, now that lets me know that he thinks it's me. See, now you're full of it.

1:30And D. And I know what the D stands for, too. Anyway.

1:38By the way, that's another name. It's a nickname for Richard. Thank you. He says. It's also a nickname for a private detective. That's correct. Private Dick. That's right. Yes. And that's why in the opening song to the movie Shaft, Isaac Hayes sings, who's the black private dick that's a sex machine to all the chicks? Yeah. I don't think he was talking about investigations.

2:04That was a line I had to, like, listen to a few times. And then I had to look up the definition, and one of the definitions of Dick was private detective. So that was a weird. That's right. Sort of scripting there. Okay. Go ahead. Go ahead. Way to go, Isaac Hayes.

Planet Nine

2:20He said, I've heard there may be a large planet or dwarf planet orbiting beyond Pluto. Planet nine. The so-called planet X. What exactly are the scientific observations causing this suspicion? Could the new Rubin telescope find such an object? Thank you, Andy, from Thousand Oaks, California. I do not know the targeted zones of the Rubin telescope. Generally, if you're going to find a planet and you don't know that it's a planet, you need

2:55several observations because otherwise the stars, though they move to orbit the galaxy, are so far away from night to night, they basically keep the same position. But something orbiting the sun would not from night to night, week to week, month to month. So I think, in principle, the Rubin telescope would be able to detect such a thing. But it would have to be directed to a region of space where we think it is and then hang out there just for that purpose.

3:27But that's not what the telescope was designed for. It was designed as a survey telescope of the entire sky looking for whatever moves in the survey zone. So that's my first point. Second, the way we have colleagues who think about this and do these experiments, there are these the Pluto we discovered in the last 20 years, 25 years, is just the most prominent member of a new swath of real estate discovered in our solar system called the Kuiper Belt, named

4:02after a Dutch, I think, Dutch-American astronomer, Gerard Kuiper, by mid-century. He hypothesized the existence of a repository of comets that didn't participate in the formation of the rest of the solar system. In fact, he made the inverse prediction. He would say, he said, there's a region out there where there would be comets if they didn't participate. Okay. It was one of those kind of backhanded predictions. Turns out there are thousands of dirty ice balls orbiting well beyond Neptune, including

4:38Pluto. So, and the Kuiper Belt is huge. So, observations of Kuiper Belt objects tell us that maybe they are responding to another source of gravity in the outer solar system and not just in their orbit around the sun. There's movements that can't otherwise be explained if they're simply orbiting the sun. So, that allows you to say, maybe there's another source of gravity out there that's mysteriously

5:12tugging on these objects we do see. Now, if it's a planet, it's going to be much bigger than just a Kuiper Belt object. But if you can't see it, it must be much farther away. So, they're placing it at a distance below their detection limits because they're saying, otherwise, we would have seen it. And when you do this, this thing is really far away. So, there's still a lot of speculation. There's been some skepticisms of the observation and the interpretation, but that's what it is.

5:42And that's how we infer that there might be a planet nine or a new planet X because we all know Pluto got done demoted. Right. Yes. So, there you have it. And Andy crawled through a mile of... Anyway. Anyway. Okay.

Eric's Question

6:07All right. This is Eric Leroy who says, Greetings, Neil and Chuck. Eric Leroy here, exercise physiologist and spaceflight physiology researcher from NYC. And my question is, what are the requirements established by the IAU that led to the demotion of Pluto as one of the major planets of our solar system? In my opinion, they are not specific enough and should include granular measurements in addition to the phrase clearing its neighborhood. I believe if Pluto was given its title as the ninth planet back, there would be a surge in scientific and astronomical interest around the world of all ages.

6:48Thank you for all that you do in the name of science. So, he's saying, let's create a controversy that will spur interest in astrology once again, astronomy once again, by giving Pluto planetary status back. The rules weren't diabolically conceived just to get rid of Pluto.

7:21It's not how that worked. Okay. So, here's what happened. Let me remind people. As our telescopes got better, as the Keck telescope started looking in the outer solar system, in the region of space where Pluto orbits, we started finding other objects. And there was an object whose size rivaled that of Pluto, and no one was prepared to call that a planet.

7:53So, that forced a whole fresh look at what Pluto is, where it is, how it's orbiting, and why. On doing so, we found, not only is Pluto more than half ice by volume, like comets are, Pluto is orbiting a region of the solar system that we would discover has countless thousands of other icy bodies in the outer solar system.

8:30These, we would more commonly call comets. Pluto was the first discovered because it was the biggest and the brightest. You would expect the biggest and the brightest to be discovered first. Then we have better telescopes, and now they're popping up. We've lost count of the number of Kuiper Belt objects that are out there. So, this is not different from the year 1801, where a new planet was discovered, orbiting between Mars and Jupiter.

9:06That was a big gap anyway, between Mars and Jupiter on a planetary scale. We said, something has to be there. Let's keep looking. We found a planet. We called it Ceres, named in the tradition of a Roman god, as were all the other planets. Then we found another one, and then another, and then another. Ceres, Pallas, P-A-L-L-A-S, Vesta, and Juno. Wow. And it says, wow, the planet count just took a big leap.

9:37And then we said, well, wait a minute. How come when I look at them through a telescope, you don't see a disk the way you see a disk? Like you see Jupiter, you see weather bands on it. Saturn, you see rings. You know, that's Pluto calling you right now.

10:00When you look at the other planets, you see the physical spherical object that is the planet. When you look at these planets, they're just dots of light. They're really tiny. And we know they're orbiting the sun and they're reflecting sunlight because we can follow the orbit. But when you look at stars, they're just dots of light. But we know these are not stars. They're just star-like. Wait a minute.

10:30What's a word for star-like? I'm going to say asteroid. Asteroid. Once we started discovering dozens of these things, we said, we can't call these things planets. What instead has happened is that we have discovered a brand new swath of real estate in the solar system that we didn't previously know was there. Another belt. A belt. And generally, it's a belt if it's flat but goes around the circle, like it rims the sun.

11:04The asteroid belt. So overnight, those four new planets were, quote, demoted to asteroid status. And now there's countless hundreds of thousands, likely millions of asteroids discovered and cataloged orbiting in that zone. Okay. Having discovered Pluto first and thinking it's a planet and then discovering another object and another. And we've kind of been down that road before. We have countless Kuiper Belt objects, all in an orbit that is spread around the sun, enclosing the trajectory of Pluto.

11:42That's the first strike against it. It's not isolated in its orbital zone. It is one among many whose size rivals it. Wow. Okay. Two. Yeah, it's small, but that alone doesn't indict you. It's big enough to be a sphere. If you're small, if it's got enough mass to be a sphere, if you have much less mass than that, then the gravity doesn't overcome the structural integrity of the rocks and the rocks went out.

12:17So most asteroids look like Idaho potatoes. Okay. There's whatever the rock is, that's its shape. But when you get bigger, gravity pulls the high places into the low, fills them in, and you become a sphere eventually. Interesting fact about gravitational physics. All right. So Pluto did not clear its orbit. Pluto, because it's in a swath of real estate completely filled with other objects that rival it in size.

12:49What else do you have to be to be a planet? You have to be big enough to be round. Pluto is big enough to be round. It is. But it needs more than one criterion to be satisfied for planet status. Having failed one of those two, it got, quote, demoted to dwarf planet status. However, you know, Ceres, the first asteroid discovered, that's the only asteroid that's round.

13:21Of course, it was big enough for gravity to make it round. And of course, that's going to be the first asteroid you discover. Ceres has more mass than all the other asteroids combined. So Ceres got a promotion. At the same time Pluto was demoted to dwarf planet, asteroid Ceres was elevated to dwarf planet. And so Pluto has company. There are many dwarf planets in the solar system to join it. And it has, and like I said, it's half ice by volume.

13:54If you brought it to where Earth is right now, heat from the sun would evaporate the ice and it would grow a tail. And the third criterion I left out, sorry, you can't cross the orbit of other planets. Oh. That's a no. Pluto spends 20 years out of a 48-year life closer to the sun than planet Neptune. It crosses Neptune. It goes to the outside, to the inside. To the inside. And by the way, that's what planets do that routinely.

14:26They cross all the planet orbits as they plunge in towards the sun. Right. So out of three criteria, Pluto failed two of them. It's a fraud, Pluto. You're a fraud. However, however, while it had planetary status, we discovered a new element. It basically invented a new element in the laboratory that we named after Pluto. And so Pluto now has an element on the periodic table from false pretenses.

15:01Just thought I put it out there. And in sequence, there's element 92, which is uranium, named after which planet? Take a guess. I'm going to say Mars. No, of course, Uranus. Uranus. And then there's Neptunium, that's element number 93, named after Neptune, and element 94, Plutonium, named after Pluto. Pluto was discovered in 1930. Plutonium was isolated in 1940.

15:32It was weaponized, turned into a bomb, and used in warfare five years later. Damn. Damn. That's right. Wow. Oh, look at that. Pluto, the most destructive non-planet ever.

15:52Wow. That was the first time I've seen you give that exhaustive list of Pluto's failure to be a planet. Anyway, well, listen, Eric, I hope that did it for you, man, because it's hard. Get over it, otherwise. Yeah, it's, yeah. Get over it. That's terrible. I know. But really, get over it. All right. Thank you. Thank you. Hello, I'm Vicki Marock-Allen, and I support StarTalk on Patreon.

16:37This is StarTalk with Neil deGrasse Tyson.

Nirav's Question

16:40Let's go to Nirav Shah, who says, hello, Dr. Tyson, Lord Nice. I am from India, now living in Arizona. I have listened to you, Dr. Tyson, for years, and appreciate your storytelling such that it helps me recall things, and I share it with my fellows. Could you please share the connection between theory of relativity, quantum physics, and semiconductor physics, how the former eventually allowed the latter to develop?

17:15Thank you for everything that you guys at StarTalk do. There's no direct connection that I know of between relativity and what happens in a circuit board. But relativity is what we call modern physics, which was discovered in the 20th century, just as quantum physics was. So often, if you take a college class in modern physics, you learn both relativity and quantum physics together in a first introduction, in your first step beyond classical physics.

17:49All right. So quantum physics, quantum, people say you took a quantum leap. A quantum is a very small unit, discovered originally as a small unit of energy that cannot be continuously varied. A quanta of energy. You can't have one and a half quanta. You can have one, you can have two, you can have three, you can't have fractional quanta. That's the whole construct of that understanding.

18:22So in circuits, you're moving electrons around. To understand electrons and what they do and who they behave and why, you need quantum physics. You need quantum physics to understand anything that's going on inside of molecules and atoms and nuclei. So you don't have to single out the semiconductor and its importance to civilization being fed by innovations in quantum physics because it's all quantum physics.

18:56So I don't know how to reply other than to say just a couple of things about semiconductors. A semiconductor typically uses a wafer of silicon, which is an insulator mixed with some other material that's a conductor of electricity. Insulator does not transmit it, conductor does. Semiconductor is configured so that you can control the passage of electricity at will and on command depending on the needs of the circuit.

19:27And so semiconductors became highly useful, especially in computing. And the race was how to make the tiniest semiconductor that had the most number of circuits in it. So you can, when I grew up, computers were the size of whole rooms. That's how old I am, right? Those were four function calculators.

19:51Walk into the room and it's like, it was hot because it had vacuum tubes that were, that radiated heat. Quantum physics enables the IT revolution entirely. And so I don't know what more to say about that. Other than that, we're in the centennial decade of quantum physics. And let's celebrate that fact because civilization as we know it would not exist without it. Well, thank you, quantum.

20:22Yeah. There you go. All right, let's move on to Derek Evans.

Galaxy Shapes

20:28Hi, Dr. Tyson, Lord Nice. Derek here from South Windsor, Connecticut. My question is about the shape of galaxies. As we know, they take many forms outside the stereotypical spiral shape. But what ultimately dictates a galaxy's shape? Do they all rotate? And if so, does shape indicate age or developmental stage? That sounds very psychotherapy. What is your developmental stage?

21:00Are you lagging behind? I'm a little stunted. You know what I mean? All the other galaxies seem to have it together, man. You know, I'm just really confused all the time. And I'm so angry all the time, too. I don't know if it's because I'm a spiral galaxy or a sombrero galaxy. I honestly don't know what my identity is. There is a galaxy named the sombrero galaxy. It's not a kind of galaxy. It's the name of a galaxy. Oh, is that the name?

21:30Yeah, it looks like a sombrero. Yeah, yeah. And it looks, well, okay. There you go. Okay, so if you start out with a gas cloud. Right. Huge gas cloud. Okay. If it's, depending on how fast it's rotating, if it's hardly rotating at all and it collapses, it doesn't flatten. It stays kind of three-dimensionally. Globular. We call them elliptical galaxies. Oh, really? They're spherical, elliptical shapes. Okay. And they rotate very slowly.

22:02Okay. All right. If you have more rotation than that, you will flatten as you collapse. And you become very flat, flatter than a flapjack. You become as flat as a crepe, almost as flat as a tortilla. And so our galaxy, the Milky Way, when seen edge on, would almost disappear from your sight line for that reason. And what happens is you, a galaxy gets stars from its gas clouds.

22:33And in this elliptical galaxies, for reasons not fully understood or were not fully understood the last I looked at this problem, that's the more, the safe way to say that, elliptical galaxies were very efficient making stars. So they made all, they used up all their gas and made all their stars and there's no gas left. So when you don't have gas, you're not doing what? I'm going to say ruining the dinner because you're rude at the table. Yeah. Gas. These are different gases, Chuck.

23:06Not hydrogen sulfide.

23:11So, yeah. So elliptical galaxies are mostly gas-free. They made all their stars early on and the stars are just aging right now. Whereas spiral galaxies, they retained 10%, 20%, sometimes 30% of their mass in gas. Wow. So there's still stars being formed. So when you see those beautiful photos from JWST and Hubble of these gas clouds and stuff, when you probe those gas clouds, it's where stars are born.

23:41Stellar nurseries? Yes. Stellar nurseries. So these are the differences among the galaxies. Spiral galaxies are inefficient, converting their gas into stars. Elliptical galaxies are very efficient. And so there you have it now. There are galaxies that are very disturbed looking. Those are the galaxies that are like, you come near me, I'll kill you. You think you're going to collide with me? I will kill you.

24:10Try to collide with me and see what happens.

24:16Those are the belligerent category of galaxies. It reminds me, because it reminds me of just bullies. You don't even know the bully. You step on their toe. You do that again, I'll kill you. Exactly. It's like, bro, get in therapy. What is your problem?

24:34Galactic therapy. So in my lifetime, there was a catalog of galaxies that was published by a Caltech astrophysicist named Halton Arp, nicknamed Chip, Chip Arp. And it was called the Arp Atlas of Peculiar Galaxies. He went around all the sky, the night sky. He cataloged galaxies that were just weird looking, disturbed looking, distorted looking.

25:05And we didn't have the answer to the question, did galaxies become this or were they born this way? The way, what's your name was? Lady Gaga. That's the Gaga galaxy. Were they born this way or did something happen to them? It was not until we were able to bring computing power to this problem in the late 60s, but mostly in the 1970s, where we can say, what happens to two grand design spiral galaxies if they collide?

25:41Oh, my gosh. It's a train wreck.

25:44Stars don't actually collide with each other, but they feel each other's gravity. And the gravity casts stars hither and yon. And it looks like a train wreck. So if you stop action, the footage of galaxies colliding, here they are coming near each other. Here they are partly overlapping. Here they are deeply overlapping. And you do this. Then you have a template handed to you by your computer of colliding galaxies in all stages that they could collide.

26:18Now you hold that to Chip Arp's catalog, and you can explain 90% of those galaxies.

26:27I had a mentor once who said a crashed Lexus is not a different kind of Lexus. It's still a Lexus. Why he chose Lexus, I don't know. But that was his car brand that he used. So, and there are also galaxies that are just irregular in shape for no good reason. You know what we call those? I'm going to go with irregular galaxies?

26:56Chuck, you're such a fast study here. So, we have spiral galaxies, elliptical galaxies, irregular galaxies. They look kind of like puppy vomit, you know, on the ground. You know, it's just any, it just, they tend to be very gaseous, tend to be gaseous, which means they can make stars. And then there are galaxies that are just generally small. A catch basin of galaxies. And we call them dwarf galaxies. Of course. Irregular galaxies are dwarf galaxies.

27:26You can also have small elliptical galaxies. We call those dwarf galaxies as well. You can see them going off to work singing, hi-ho, hi-ho. I wrote an essay, one of my early writing forays, where I was paid. I think I got paid $300 for this essay for a newsletter. And it's called The Galaxy and the Seven Dwarfs. That's what it was called. And because we have, our galaxy has, at the time, seven known dwarf galaxies that orbit us.

27:58Typically, a dwarf galaxy is a member of some other association of galaxies. So, there you have it. That's more galaxy evolution than maybe you bargained for. But that's the, that's how it goes. And Chuck, those are the basic categories of galaxies. Right. But there are also galaxies that just do weird things that might be hybrids of these others that I just listed for you. There are quasars and blazars and lenticular galaxies and, and radio galaxies that give mostly radio waves.

28:31So, there are variants on this, but what I described to you are 95% of all the galaxies in the universe. Okay. Well, very cool. All right. Well, thanks a lot, Nirav. Let's move on to Melinda Washington.

Melinda's Question

28:47She says, hello from North Carolina. As a new autodidact, I am excited to explore astrophysics in a focused and structured way instead of jumping between topics. How would you recommend breaking the subject into manageable pieces? What materials would you suggest? And in what order should I approach them to build a strong foundation? Thank you both for always sparking my curiosity and inspiring me to keep learning. Always looking up, Melinda Washington.

29:20Ooh, love it. Love it. So, at the risk of sounding self-serving, I co-authored a textbook with two colleagues at Princeton University when we co-taught a class. One of us taught stars and planets. The other taught galaxies. And the third taught cosmology. And we, the class started out with 30 people. And over the years, it had like hundreds and hundreds. This was at Princeton University.

29:51And so, we said, why don't we turn this into a textbook? And we did. And the textbook is highly readable. It's not like, learn this for the problem set and the syllabus. And so, the book is called Welcome to the Universe. And if you get it through the museum's website, the museum shop, I think it's shop.amnh.org, I think they sell it there. If you get it, it's pre-signed by me.

30:23I pre-signed the books that they sell with my fancy overpriced purple ink, bottle-filled fountain pen. If you don't want to jump into a textbook, there's a tiny version of it that is the, the Cliff Notes version of it, is called A Brief Welcome to the Universe. So, what you might do is start with that. That'll whet your appetite. And then you graduate to the full-up textbook. And it's, you know, it's 400 pages. It's a full-up textbook. But it's very readable.

30:54You can sit on the couch and get lost. It's a page-turner. I have one in my bathroom, Melinda.

31:06That's what I recommend. And it's very sequenced and very pedagogical, I should say. Very nice. All right. Well, that's very, that's excellent. And don't read my best-selling book, Astrophysics for People in a Hurry. Astrophysics for People in a Hurry? Because clearly, you're not in a hurry, A. B, what's in that book is me going through an entire curriculum and cherry-picking the coolest, most mind-blowing things and putting it into one volume. So I skip over stuff that you don't even know would have been there, but in a full-up curriculum, in a college course, it belongs there.

31:44But if I just want to whet people's appetite, that's what I did, cherry-picking the coolest things in the universe for that book. Very nice. Yeah. I was talking to, I was on a show yesterday and doing an interview, and the host read Astrophysics for People in a Hurry. And they said, I don't care how, how much I'm not in a hurry, I still didn't get what he was talking about. Oh, okay. So, by the way, Astrophysics for People in a Hurry is not Astrophysics for Nummies.

32:19Yeah. Just to make a, it's real astrophysics. It's real astrophysics. For its, its interest level. So, yeah, don't think it's, it's a lesser. Yeah, don't, don't think you're going to get in there, and it's not going to be like, you know, this is a galaxy. See, galaxy, spin. Spin, galaxy, spin. It ain't doing that. Okay? So. All right. This is Christy Giangu, or Giangu.

Christy's Question

32:49She says, hi, Dr. Tyson and Lord Nice. This is Christy from Romania, writing to you from Italy. Where do we get all these international people? Wow. I love it. Man. She says, it is possible that dark matter is actually normal matter hidden in the guts of the space-time fabric. I think she meant, is it possible? Because it's, it's, it's actually says it is. But is it possible? I'll read it that way. Is it possible that dark matter is actually normal matter hidden in the guts of the space-time fabric?

33:23Imagine that on a space-time fabric, there are vast regions so deformed, like crumpled paper ball, that it is impossible to see directly the matter inside those regions. Will that explain why we can't see or feel it, but we can feel the gravitational effect? It's possible to verify this measure, the time that light takes to travel through those regions of crumpled, deformed fabric, since it has no cover or larger distance than what we actually see with our telescopes.

34:00Thank you. Keep looking up.

34:05Wow. I don't know that space-time can hide things. That'd be kind of diabolical to science, if space-time is hiding crucial information from the court, you know. Trick ya!

34:21I've imagined multiple times that maybe dark matter, which expresses gravity in our own space-time, maybe dark matter is ordinary matter in a parallel universe. That's similar in an idea to you're tucking it away within folds of the space-time continuum. If it's from another universe, then it's ordinary gravity leaking into ours, forcing us to say, oh, what is this mysterious substance?

34:53We can't see it, taste it, but it's real in another dimension. And I look forward to knowing whether or not that's true, because it would be kind of cool if it was. I would love it, because to me, that theory, not theory, but that postulate says that now we've got to go ahead and start investigating other universes. Yeah, except I don't want to be the first to visit them.

35:24If the laws of physics are slightly different, you could just collapse into a pile of goo on the sidewalk. Okay. Yeah. Be careful. Well, we'll send an advanced team. Send a gerbil through. Yeah, exactly. You know. All right. This is Stephen Schultz, who says, hello, StarTalk family.

Stephen's Question

35:48Stephen Schultz from Dayton, Ohio. Thank you all for taking the time to read my question. I've recently read that the ISS is scheduled to make its fall back to Earth in 2030 or 31. Will this be something you guys plan on watching in person? Will it be possible to see it from an island in the Pacific, assuming that's where it will land? Thank you guys for all of the amazing content. So is it going to de-orbit in 2030? Yes. Well, I think we'll probably keep it up there.

36:21You know, when you threaten to defund something, people come out of the woodwork and say, no, don't do that. Keep it going. And by the way, what a great way to get funding. Well, you can cut off this money. But when this thing fall out the sky, you're on your own. Yeah. I mean, so the Pacific Ocean is the great space toilet bowl on Earth because the Pacific Ocean spans a third of all of Earth's longitude. It's huge.

36:51So that you can drop something out of the sky without much precision and you'll still hit the Pacific Ocean. Look at that. Can you watch it? Yeah. Go take a rowboat out to the middle of the Pacific Ocean when this happens. And there's no guarantee it will fall just over your head compared with other places. Your horizon in a rowboat might be 15 miles away. But reentering spacecraft, that horizon would be small compared to all the places it could land above your head.

37:24So, so, yeah, in principle, you could see it. Maybe we have drones out there filming it. But most of the space station will burn up in the atmosphere. Most of it. We expect that. And by the way, I'm not trying to go look at that because with my luck, it will fall on me. So I ain't trying. I like the idea of a drone filming it, though. Keep in mind that the space station was built beginning in the early 1990s.

37:56So how many years ago? That's 30 years. If you visited someone's home and they had a television from the early 1990s, they would be the object of mockery to you. They'd also not be watching TV. Because you can't get anything on a TV from the early 90s.

38:18So technology has advanced since then. And if you sent up a space station today, it would probably look different or be much more modern than whatever we have got going up there now. So China plans to also have like a competing space station to our own. And that's why people are a little spooked in Congress that they would have the new high ground relative to what we have enjoyed over the decades. So the real issue here, Stephen, is to get more funding for NASA and space research because let them know that we're going to lose to China.

39:00And quite frankly, they will have the upper hand militarily. Yeah, that's all it takes. And then everybody will just run with it. Yeah, there you go.

39:13This is Stephen Skilton. And Stephen Skilton says, do we know the actual odds for someone, anyone to be hit by a small meteorite, excluding large extinction level events?

39:44I find it amazing that only one person, Anne Hodges, has been recorded being struck by, and no one else in at least 1,000 years of history has been recorded as being killed. With 8 billion people on Earth, would you need to see odds on the magnitude of something like 1 trillion to 1 to help explain the lack of recorded strikes? Okay, so if we didn't have an atmosphere, you'd be dead.

40:18I would need time to do a proper calculation on this. It's a population of the Earth, how much space we take up, what the surface area is, the fact that people aren't spread evenly around the world, that not all the meteors that strike Earth make it to Earth's surface, that they burn up. So I'm going to do a proper calculation and report back. But here's something I can tell you. I was almost hit by a meteor. Did I tell you about this? You of all people, if you got hit by a meteor, everybody would say, see, there is a God.

40:54The universe killed the universe guy.

41:05Well, what God are you talking about, right? Right, right, right. I think I've told this story before. Back in 1999, I was on the Brooklyn Bridge in the middle of the night, maybe 1 in the morning, in November, for the Leonid meteor shower, which was on its 33-year cycle, where you expect not a meteor shower, but a meteor storm.

41:35Comets leave debris that make meteor showers, and that debris orbits the Earth in front of and behind the comet, and Earth plows through that at the same time each year. That's why meteor showers repeat annually. All right. This meteor shower is associated with a comet that has a 33-year orbital period around the sun. And if you're near where the comet had just passed the sun, or just come in front of the sun, you get extra meteorite flux coming in, because all the crap that falls off a comet is closer to where the actual comet is than scattered completely in its orbit.

42:15And all this debris continues to orbit the sun. All right. I'm on the Brooklyn Bridge with my three-year-old daughter, three-and-a-half-year-old daughter. I woke her up for this. Okay. We're there, and I'm watching. We're getting a meteor every 90 seconds. Not quite storm level, but definitely satisfying. Okay. Then I'm looking up, and I see a star in the sky just appear.

42:45And it got brighter and brighter. And I said, that's odd. I wonder what that is.

42:55And then it disappeared in a puff of smoke. I said, oh, my God.

43:04This was a meteor headed straight for me. But in the instant I saw it, I'm thinking, gee, I wonder what this is. I was just being curious scientists. Until I put two and two together. And then I realized the day you die from a meteor strike is the day you are staring up at a light that gets brighter and brighter. And that'll be the last thing you saw in your life. So I almost hit. I think it would have hit me because I saw no streak left, right, or sideways.

43:40And then it just simply disappeared. I was protected by Earth's atmosphere. Thank you, pollution. What? It's not pollution. No, the atmosphere protects you without the pollution. No. Oh, real? Okay. That's true. We're good. We're good. Chuck, we only have time for one more. One more. What you got? All right. Here's the last question. It's Vail Stein. Dear Dr. Tyson and Lord Nice, my name is Vail and I'm from, oh, wait. My name is Vail and I'm a seven-year-old math and science kid from Philly.

44:13What up? Seven-year-old math and science kid. Okay. Wow. He says, do black holes absorb dark matter through the event horizon? And if so, would the black holes charge, mass, and spin change? Or can dark matter flow in and out of black holes as it is not electromagnetic and only has some of the properties that matter does? All right. First of all, let me just say this. If you are from Philly, you damn sure ain't going to Philadelphia public schools.

44:45Chuck, there's a seven-year-old asking that question is not happening in a Philly public school.

45:02Damn, Chuck.

45:06No, I can't. That's my home job. Right, because you're from Philly, so you have the data. That's right. I can make that joke. I mean, I can make that joke. All right. Anyway. All right. So, it turns out the only property that dark matter has that we can interact with is gravity. It doesn't have electromagnetic coupling with any of our particles. That would mean, does it have electromagnetic forces, which are required to make molecules and hold atoms together?

45:38So, it has gravity. And if it has gravity, we are left with no skepticism over whether a black hole would just happily, just as happily absorb dark matter as it does regular matter. And the matter would not be able to come out any more than regular matter could, because it's responding to gravitational forces. So, you can bet that a black hole sucked in all the dark matter that was just in its

46:10area. All right. But if you're at a safe distance from a black hole, it's not a giant sucking machine all of a sudden. It'll pull in anything that was close. But if the sun became a black hole, for example, we would still orbit it. It would get very cold very quickly, but we would still orbit. We're not so close that we would get sucked in. And so, there's an old saying, there's no such thing as gravity. Earth just sucks.

46:39Oh, wow.

46:42So, yeah, it's an excellent question. Wondering whether dark matter would have different properties in the vicinity of a black hole. And everything we know and understand about it tells us that it wouldn't. There it is. Now, go back to your basement and keep working on the super weapon to destroy the superheroes.

47:01Exactly. Way to go, Vale. Nice, nice, nice work. Nice work. That's all the time we have for it. So, always good to have you there for these grab bags, Jack. Always a pleasure. Always a pleasure. All right. This has been StarTalk Cosmic Queries and another grab bag edition, which are always crowd pleasers. I am Neil deGrasse Tyson, your personal astrophysicist, as always, bidding you to keep looking up. I am Neil deGrasse Tyson, your personal astrophysicist, as always, as always, as always. I am Neil deGrasse Tyson, your personal astrophysicist. I am Neil deGrasse Tyson, your personal astrophysicist. I am Neil deGrasse Tyson, your personal astrophysicist. I am Neil deGrasse Tyson, your personal astrophysicist. I am Neil deGrasse Tyson, your personal astrophysicist. I am Neil deGrasse Tyson, your personal astrophysicist.

47:32I am Neil deGrasse Tyson, your personal astrophysicist. I am Neil deGrasse Tyson, your personal astrophysicist. I am Neil deGrasse Tyson, your personal astrophysicist. I am Neil deGrasse Tyson, your personal astrophysicist. Thank you.