The transcript covers a variety of cosmic and scientific questions. Neil deGrasse Tyson explains that time measurement relies on repeated motion, and space cannot exist without time. For a 12-year-old, he recommends his own books, "Astrophysics for Young People in a Hurry" and "Merlin's Tour of the Universe," for accessible science. Regarding the universe's edge, he clarifies that from any point, the universe looks the same, and our horizon expands at one light-year per year. The Silurian hypothesis is dismissed because fossil evidence of advanced prior civilizations is absent, though Earth's crust recycling could obscure evidence. Black hole singularities are discussed as mathematical limits of general relativity, potentially resolved by quantum physics. Transparency in materials is explained by atomic structure affecting light paths, with diamonds slowing light to create brilliance. Finally, mining the moon is considered unlikely to impact Earth's tides significantly, as lunar mass would likely be used in space rather than brought back to Earth.
Chuck, we just did a grab bag and people ask questions from all over the world. And finally, we know if you wear boxers or briefs. Not coming up on StarTalk Cosmic Queries. Welcome to StarTalk. Your place in the universe where science and pop culture collide. StarTalk begins right now. StarTalk Cosmic Queries. Oh yeah. Chuck. Hey. You want to help me out here? Of course. Yeah. Is there a theme today? Nope. This is a grab bag. Just random. Whatever they want. Ask me anything. Let the people speak and ask. Okay. Let's get right into it. And choir minds want to know. Here we go. Okay. Eric 44 says, Hey, legends. Eric here. Exercise, physiologist and space flight physiology researcher from New York. City. Love it. Look at that. Love it. He says, My question is all motion requires time, but does all time include motion? I would say the measurement of time requires not only motion, but something that repeats. Okay. Think about it. Right. Have you ever measured time with something that did not repeat periodically? The answer is no. No. You can't. A day repeats every day. Seconds repeat. Everything repeats. Months repeat. Years repeat. Right. So where there is no repeated motion, there can be no coherent measure of time. All you'd be able to do in your own reference frame is sequence events. This came before that. Before that. Before that. Right. I remember in the before four times. No, the before four four times. Right. I'm older than you. Right. Before four four. So now the sequence of events can be different depending on your reference frame. Relativistically, you could be moving in a different direction and you will experience those events in a different sequence than I will. But in my reference frame, like I said, if nothing repeats, time cannot be measured. Right. With any meaning or repeatability. So that's a great, it's a fun, interesting philosophical question. Yeah. And, but space can exist without a time, I would think. Space on any time. No, it doesn't. I mean, it's, it's space is like, I'm here. You know, I'm not going anywhere. You want measure something? That's what you want. I'm here, which is measured. I'm right here. So there you go. That's very cool. There you go. Eric 44. It was a great one. Well, we're off, we're off like a rocket. This is Maurice Backer. Says dear Lord, nice, dear Dr. Tyson. I am Iljada from the Netherlands and I am 12. My question is, what is the one book that every 12 year olds should read? And my name is pronounced E-Lyda. Okay. Thanks for the phonetic there. He lied. He knew the France. Yeah. And yeah, yeah, yeah. Anyway, no, no. Okay, Iljada and I didn't get it right. I actually read these beforehand. Anyway, universal respect and greetings. What a mature 12 year. What a very mature 12 year. That's clearly not run by an American count without a doubt. You know. Yeah. So, I'm very biased here because I only write books that I think people should read to get them enlightened about the universe. Okay. And I find gaps in the publishing landscape. All right. Scientific landscape. I'm going to bridge that gap. I'm going to put something there. Right. So, I can say at age 12, writing like that, and plus the Dutch, they flew into English. Yeah. Yeah, without a doubt. Okay. So, even though there are fruits and fruit and fruit and fruit, no, no, no, no, no, you mixing that up with the sweets. With the sweets, I know, but it's funny. You know, I like, like Dutch is actually, that's actually Dutch, but it doesn't make for a funnier, you know, fruit and fruit and fruit and fruit makes for a funny joke. But anyway, you're right. My book, Astrophysics for People in a Hurry. Okay. Okay. Has a young people's version of it. Oh. Called Astrophysics for young people in a hurry. Now, I keep thinking young people should never be in a hurry. Yeah. Well, they got to get back to them video games. No, I mean, I mean, I mean, just a little quick as Valorant is waiting. Hey, Louis, go play it self. Gotta get back to the video game. Let me see what Neil says before I get back to Roblox. So that book was conceived for ages 8 to 12. Oh, wow. Which collectively is called the tweens. Right. Right. And its value is, it's not just that it's a dumb down. No, it folds in a lot of my own background when I was that age because I was a geek kid. And so you get to sort of live with me through your own years that you're reading the book. That's cool. Okay. I still have value to a percosis 12 year old. But if not, then just go right to astrophysics for people in a hurry. It's not astrophysics. It's real astrophysics. It's astrophysics. It's astrophysics. Right. But I have cherry picked it for the coolest stuff in the whole universe. Right. And that's what's there from Big Bang. I call it the book you should read when you don't really want to know the granular details, but you want to be able to have a cool conversation of a cocktail. Totally equip you to do so. Exactly. So there's that. But then if it just wants to have fun, definitely the Merlin book. Oh, okay. Merlin's tour of the historical universe. It's a Q&A. He's asking Q question answer right now. It's illustrated by my brother. Oh, cool. It's just a fun, I think it's a fun book. So forgive me for recommending my own book. For shamelessly promoting myself. No, you're supposed to. That's great. That shameless, I'm doing it with. No, he joined it with. Right. I'm like, I know what I'm doing. No, same attest. So I think he will enjoy those. I'm certain of it. Okay. Because they're written with that in mind. That's all. Now is it Liza Boy's name or girls? I don't know. I don't know. He or she. Liza. Okay. Let's de-genderize it. Yeah. We'll call them a day. They. So Liza, sorry to misgender you. In fact, that's what I did. But those, I think any of those three books will, as Chuck said, you can get some good reading in between video game playing. We're going to play it. So. All right. Here's Andrew Bowen. I'm writing at the edge of our universe since the big bang. And moving with the expansion. What does it look like when I'm facing back at us and what does it look like when I'm facing outward ahead? It looks just like it does here and now. We are at the horizon of anybody who's at our horizon. Exactly. And anybody at our horizon sees the universe all around them like anybody else does. There you go. Yeah. That's right. So what will happen is, imagine this instant, go to our horizon in this instant, light from us, emitted 13.8 billion years ago is only now just reaching you. You will see all of us as galaxies being born. Right. So this would be your horizon. That's what it is. How did it work? So yeah, that's so cool. You're all equally as far away from the origin of the universe as each other. It's like being in the middle of the ocean. Yes. Yes. Yeah. You go to your horizon and still you still have the ocean. You still have the ocean. Right. That's so cool. Wow. Great question, Andrew. I love it. Oh, by the way, we don't know how far the universe extends beyond our horizon. Right. Just the way you don't, there might be a point where land shows up. Right. No matter how big the ocean is. Right. So there might be a point where you run out of galaxies and stuff. Right. You don't know that because every direction we look, we see galaxies being born. Exactly. So we are deep within a space-time continuum that's much larger than our own bubble. Yeah. Yeah. But you know what happened? If. If. If. One day. Yeah. The cosmic microwave background disappears. Uh-oh. Uh-oh. And that would mean that our horizon, which is expanding at what rate? Well, it's got to be. Well, suppose, is that faster than speed of light? No, no, no, no, just a visual horizon. Uh-oh. It's expanding at one light year per year. Right. So in a billion years, we'll be 14.8 billion years to our visual horizon. All right. So the point is, if the cosmic microwave background disappears. Right. And then you just see galaxies up to that edge. That means our horizon is washing over a part of the universe where there is no matter there are no galaxies. Oh. reach the edge.
of any material substance in the universe. - Right, 'cause we're, now wait, is that because we're traveling? - No, no, no, no, no, no. Our horizon is continuing to move out. - Oh, 'cause it's moving out. - It's moving out. - Right, it's moving out. - So it will always find a galaxy being born. - Right. - Okay. It's until it does. - I got you. And so, right, once we get past that, that means nothing's there. - Nothing's there. - Oh, correct. - Now. - That's like, that's finally getting a question and land. - Right. - Yeah. - All right, wow, that was cool. (upbeat music) - I'm Jasmine Wilson, and I support Star Talk on Patreon. This is Star Talk with Neil deGrasse Tyson. (upbeat music) So let's go to Young Han. Young Han. - Well, Young. - Why are you in G? - Okay. - Young Han, who says, Mr. Tyson, I love your work and your show. Can you talk about the salurian hypothesis and how it impacts how we should view our own species, civilizations, and specialness, or lack thereof, here on Earth? If advanced civilization is so fleeting and difficult to detect in our own fossil record, is it going to be easier or harder to detect in space? - Wouldn't it be fun if we were just the (laughing) intelligent civilization to rise up on planet Earth? Or even the end civilization of humans that had rose up and destroyed themselves again multiple times. - Right. - So you'd think, I think we would see a record of this. - Somewhere. - Somewhere in the fossils. - Right. - You'd think. - Right. - There'd be a statue of liberty sticking out of the ground. - Damn you! - Damn you! - Damn you all the hell! - You rapes. - That's an example of a salurian civilization. - I predated the planet of the apes, 'cause that was Earth. - Right. - Okay. It seems to me we would find a record of it. But if we find bones, we find other fossilized artifacts of dinosaurs from 65 million years ago. - Right. - Then, and by the way, the biggest mammals of the day were these tiny little rodents running underfoot trying to not get eaten by T-rex as hors d'oeuvres. - Man. - Okay. So you can't presume that they were big brain mammals before that, 'cause that was the origin of the mammals on Earth. - Right. - Around that time. - Right. - Is there a possibility that the civilization before us were not mammalian? - Okay. - So I haven't seen any, like, dinosaurs, casinos. (laughing) - I mean, just you would see things. We're not ignorant of the history of what happened in Earth's crust. Here's where you'd have a problem. - Go ahead. - You can ask the question, what is the timescale for all of Earth's crust to get subducted back down and come out in a volcano? - Oh, 'cause that would destroy all of that. - All the evidence will be gone. Because it'd become molten, and then it would spew out again and cover the Earth. - Completely gone. - Right. - Okay, so different parts of the Earth are younger than other parts. - Right. - The middle of Iceland is brand new. - Right. - Like, all of it yesterday. - All of the big islands in the Hawaii. - Iceland is on the Middic Atlantic Ridge that is spewing out. I visited there recently. - Yeah, yeah. - This is a whole new land between where I was standing and another ledge on the other side, and I did the math because continents drift about the rate your fingernails grow. - Oh wow. - So I did a fast, and I calculated how many millions of years that would have taken. - I still, it's new land compared to other places. - Okay. - You go to places where it's not regenerated that rapidly, and you don't find other evidence. - Okay. - So. - So yeah. Yeah, it's very unlikely, which is, yeah. Unless the dinosaurs were like the ABC TV show that used to be called dinosaurs. Where you never saw that? - No. - I just remember it was a little dinosaur, and when I remember-- - I just remember the cartoon "Land Before Time." I remember that one. - Yeah. - "Land Before Time." - Yeah. - Do I know that one? - It's a cartoon movie here. - I don't think I know that one. - What? - Yeah, dinosaurs that was like-- - Oh, they were just living. - They were just living like regular human beings. They had jobs, and everybody worked for one corporation called the We Say Still Corporation. And-- - How did I miss this? - Yeah, and then there was one little baby dinosaur, and every time his father would come in the room, he would jump on his head and hit him when a pot and go, "Not the mama, not the mama." In other words, I don't want you. - Get me mom. - So this is like the Flintstones except their dinosaurs. - Yeah, that's it. - That's the whole world today. - The whole world, just like the Flintstones, but all run by dinosaurs. - Okay. - It was a pretty wild little show back in the day. - There's the thing about the size of their brains, there's an issue there. - Oh, okay. - I'm just the higher levels of thought. - The higher levels of thought, they might not be president. - They might not be happening. - In a dinosaur who is bragging. - So it's a intriguing idea. - Yeah. - And I don't, but I think we would see evidence of it, and we don't. - Gotcha. - And so in that case, the absence of evidence is evidence of absence. - Ooh, I love it. - Which is not always the case. - Not always the case. - Yes. - Okay, here we go. All right, this is James H. English, who says hello, Dr. Tyson, Lorde and I. Since James from Denmark, by the way, James, we apologize. We're so sorry. And you know, all this talk, Greenland of Greenland, we had nothing to do with it. Okay, we're just letting you know. All right, it's like, you know, it's like our uncle got into the liquor cabinet while he was on his meds, and now he's just sitting in a chair going, "I know we should back Greenland, "that's what I think." So I'm sorry. So here's what James says. I heard on the previous episode that what we think of as singularities at the heart of a black hole may not actually exist. But I'm not sure I understood. We know black holes exist, but what does it mean to say the singularities may just be mathematical artifacts? - Yeah, good question. - Yes, love these. - Pretty wild. - So if you just follow general relativity math, - Right. - The object collapses under its own weight. As it collapses, the gravity on its surface continues to rise. It reaches a point where the gravity on the surface has an escape velocity greater than the speed of light. At that point, light does not escape, but it continues to collapse. When we talk about the size of a black hole, functionally we're talking about the size of the event horizon. - Mm-hmm. - But inside the event horizon, all bets are off. So the matter keeps shrinking. According to the general theory of relativity, the gravity is so severe that nothing can stop it, and it shrinks to zero. - Zero, right. - Right, and wow. - And that's just crazy, right? - Right. - What's that even mean? - That doesn't mean. - We all presume that there's some other law physics that's gonna prevent that, but that calculation is that the limits of the applicability of the general theory of relativity. - Gotcha. - So that's why we know in advance that the general theory of relativity has limits. - Right. - Limits to its applicability. - There you go. - Right. - Because quantum physics have yet to find a limit. - Right. - And we got smart people on that frontier, strength theorists, who are trying to send the math into that singularity to try to resolve that problem. And it's-- - Because if you do, then you reconcile-- - You reconcile the general relativity with quantum physics. - Yes, you will. - Yeah, that's pretty wild. - Yeah, and more playfully, this fact that it goes to zero, right? - Some people say that's where God divides by zero. - Mm. - 'Cause you know, you remember you're not supposed to-- - You can't do that. - You're not supposed to do that. - You didn't say it, you came back by zero. - I still don't know why. I'm just like, you know-- - Have you tried it? - 'Cause zero divided by zero is, I got nothing. - No, that's undefined. - Right, that's my point, but I can't define it. I started with nothing. I divided nothing. I got nothing. - Nothing, nothing, nothing. - There you go. - That's a good song. - Okay, thank you. - I'm not in the question. - Yeah, yeah. - When I first heard that song, I said, "Really, is that the best math you can give me?" In this disco era. I was in high school when I came here. - Everybody was high on cocaine. - Oh. - Yeah. - They weren't trying to do math. - Who are you trying to impress with this math here? Certainly. I could hook you up with some good formulas. - Oh, that's so funny. - Okay. - Okay, here we go. This is Michael Trilling. He says, "I'm an artist and I have been working in stained glass recently." - Ooh. - You had me thinking, "How can light travel through some materials but not others? What makes something transparent at an atomic level?" - Yeah, so I don't have a good answer for that. I have an answer, but I know in advance it's-- - It's not good. - Correct. So I'm giving like a just-so answer to that. - All right. - Okay. So transparent media. There's nothing to change the pathway of the light through the medium. And so it maintains a straight direction. - Okay.
And so it comes out the other side, you see whatever was on the previous side of that material. If the structure of the lattice or the molecules or the atoms is such that the light is either absorbed or dispersed, because it can still be transparent to light, but you can't see through it. What's the word for translucent? Translucent, okay. Light still gets through. Frosted glass. Frosted glass, but the path the light took was varied, and so there's no coherent image that comes through to the other side. There's a little known fact, as this person surely knows, light travels slower in a medium than it travels in a vacuum. Right. The travels slowest in a diamond, which helps it internally reflect so that when light comes in from one direction, it pops out a different direction. Right. When it's cut, when the facet is just right. Right, right, right. So that's why diamonds have a certain radiance of their own. Right. They're just really messing with the light that came in. So Rihanna was wrong. It's not shine bright like a diamond. It's just reflect. Refract like a diamond. What was that from Ocean's 8? No, she has a song, shine bright like a diamond. Oh, sorry. Everybody's not shining. It's not shining at all. Right. Is that why they put her in Ocean's 8? Probably, and that, and she's Rihanna. (laughing) Okay. Okay. Couple more. All right, here we go. Alex Romilian says this, "Greetings, Dr. Tyson, and your rad tag team "of lifelong learners. "I'm Alex from Northeast England. "My question, there's a lot of talk about mining the moon. "Wouldn't that be a bad idea, "considering if we're transferring mass from the moon to Earth? "We won't make the moon lighter "because of the gravitational effects "that has on Earth, i.e., the tides. "To weaken over time and eventually stop, "what other effects could it have "regards from a lifelong learner?" I love it. I love lifelong learners. Yes. Thank you for checking it. Yes. Okay. Couple of things. Couple of things. First, two things. So, it is likely that whatever we mine on the moon will stay on the moon or go to other places in the solar system where we're doing work. Right. It's not likely that the moon has something so valuable that we need to bring it back to Earth. Especially since the moon was carved out of our crust in a collision between a Mars-sized proto-planet and Earth. Its site-wife's crust goes into orbit, co-less is to form the moon. And so the moon is our crust. That's probably not too valuable. No, it's not too valuable. Not too valuable. To go there and then bring it back. So now, but suppose we did. It's okay. Suppose we mined 100% of the moon all right. But the whole damn moon back piece by piece. I love it. Okay. All right. We still have tides. Right. From the sun. The sun. All right. Because sun tides are about a third as strong as the moon tides. All right. So you still have tides. Not as big, not as bodacious, but you still have tides. How much heavier does Earth weigh? The moon is a little more than 1%. The mass of the Earth. Oh, that's nothing. That's nothing. I ain't doing that. That's a mess. Like if, so if you weigh 100, I'm a skido on an elephant. So if you weigh, so 100 pounds on Earth, you'd weigh 100, and one pounds and a little and change. Oh, no, that's barely worth. If you fluctuate that, just not worth it. Between meals and between poop. Right. Okay. You fluctuate. It happens to me every morning. Yeah, man. Get up on the scale like damn. Go to the bathroom. So yeah, it's not, don't worry about it. Yeah. It's a big moon, but Earth is even bigger. There you go. We good. All right. This is bass. Oosterveld. And bass says greetings. Dr. Tyson, Sir Chuck. Bass from the Netherlands here. Something that's bothered me for a while is the term time. Ooh. Why do we still call it that? Time is an absolute. It's relative. An experience differently depending on our motion through space time. A photon doesn't experience time at all. Wouldn't it perhaps be better to rename time? In a scientific context with something like observer-related perception of reality, not be a better representative of what we should call time. I'd love to hear your thoughts on this. Have a beautiful day. I don't have a more time for this. Mr. Oosterveld. Okay. I have one answer. So it's a cool, cool little thing that he's positing. Time has one syllable. Exactly. And what he read, the account of syllables. Count the syllable. Observer relative perception of reality. Like it's 14 syllables. 14 syllables. Right. Exactly. So take that word and make it mean what we wanted to mean. And by the way, that's the meaning of the word. And you can't even say what time is it with his, you would have to say, what is your observer related perception of reality right now? And there's certain things that we do just because it's simple. For example, our words that describe the sun and the horizon are pre-capernican. I don't say to you a chuck at what time does Earth rotate such that our sight going to the horizon reveals the sun sitting out there in space. I, instead I say what time was sunrise and when sunset. And when sunset. Right. And I think we're okay with that. Yeah. Because the sun didn't really rise at all. Well, from your point of view. Right. But still, it's a simple, two syllable word. Yeah, really so. So, I don't mind precision, but not at the expense of economy. All right. Very cool. All right. Here we go. This is Zach Sweet and Zach says, hello, Dr. Tyson Lorde and I. Zach here from Moonsville, New York or Monsville, New York. You've talked about knowing mathematically how to create a wormhole in previous cosmic queries and other explainers. I was wondering what is keeping us from taking the mathematics from paper. And applying them to the physical world going from script to screen. So to speak. I like that. Thanks. And advance. I like that. So, the problem is we're missing an ingredient. Oh, really? Yes. We need matter or some substance that has negative gravity. Uh-oh. Okay. So, matter has gravity. Right. And matter can make black holes where you're compressing things down into one place. Right. And a wormhole requires you pry open the fabric of space time. Gotcha. So, you'd be parking this negative matter, this negative gravity substance in a way that you pry open a tunnel through the fabric of space time. The fabric of space time itself. It's up. So, we would know how to configure it. Right. How much of it we need. Right. But we don't have it. Gotcha. And the people who say, well, what about dark energy? That's a negative gravity pressure in the vacuum of space. Of space. Right. Since we don't know what it is, I'm not saying let's set up a factory to make wormholes out of it. I'm not ready to do that. Okay. Right. And if one day we know what it is and then we can harness it and then package it and sell it. Yeah. And I'm all in for wormholes. Oh my gosh. That would be very cool. I want wormholes everywhere. Yeah. Like in the back of your refrigerator connected to your grocer. Okay. And then we go on Homer Simpson on me. No, I'm running low on milk to check on you. I just reach into the refrigerator. I'm at the grocery store. Grab some milk. Oh no, the grocery does have for you. Oh, oh, he'll just keep your package. Oh, he stocks your fridge from the wormhole because they just opened it up. All right. I take it back. That's totally dope. I love it. Yeah. You never low on any supply and they'll know the rate and you don't have to go travel. Yeah. And oh my gosh. Wow. That is fresh direct direct. That's the wormhole addition of fresh direct. So and there's so many things that we just take for granted require transportation systems that would just be rendered obsolete with wormholes such as on Star Trek, the transporter. Right. Right. You don't need to deconstruct the material higher body molecularly put it into a pattern buffer and then be make somewhere and recreate it hoping you get the same pattern in the exact same sequence with memories and everything. Yeah, you just walk to a portal and you're there. There you there. Yeah, that's you there. Exactly. It would render that solution to travel obsolete. Yeah, but it would just ruin like the most awesome effect that Star Trek came up with. Which is very cool. I took a time for two more. All right. I'm done with that a lot done today. Wow. All right. Here we go. Am I getting better at giving short answer? Maybe I think the questions might be helping. No, I'm talking talk. Yes. Here we go. This is James Liggett. Hi, y'all. This is James from Midland, Texas. Midland Texas.
- No, no taxes, I know Middland Texas. - The place where baby Jessica fell down the well. James, let me explain something, James. (laughing) - Let me just help you out for a snack. (laughing) - That is not a claim to fame. (laughing) - It's the top. - That y'all let a little baby fall down a hole. And it couldn't get her out. And that the whole country had to find about it. - The whole country learned about it. Before you were able to get this child out of that hole, okay? - I know Middland is a, it's a, it's a Twin Cities there. - No desert. - Middland and Odessa, okay. - Middland, the rich folk live in Middland. - Oh, okay. - And back when I was there, that was the, - That was the, - It was a very clearly understood divide. - I got you. - In the landscape. - All right. - Well James says this, since photons have no mass, how do they carry the image of their source to say a telescope or an eyeball? So what does it mean to say, we see something because we process photons. There seems to be nothing there in a photon to process. Where, in the mass, in the massless energy of a photon, is this information that we receive, this keeps bugging me man, so please help. - Let me, let me hook up my, my board from, - From Middland, all right now. - Middland, Middland Texas. - Middland Texas. - Middland. So, here you go. - Here we go. - If you took all the photons and just crammed them through the one little opening and didn't have a lens, then you would not have an image. You would just have light. That's what we do when we take a spectrum of an object. We take all the light, funnel it down into what's called a slit, goes through the prism or equivalent device, and you see how much energy, how many photons of different wavelengths is coming from that source. It's not an image at all. - It's not an image. - You don't know what the hell the thing looks like. - Right. - There's many that are red, there's many blue photons, this has extra photons in a particular place 'cause an atom is sending you energy extra in that zone, and you just look at the spectrum, and that is a no image measurement of the object. If you take the photons and have a lens, then there's a photon that came from your nose, a photon that came from your toe, a photon that came from the top of your head. It's a different color, 'cause your hair's black, your skin is brown, your shoes are red, and so there's a red photon, there's a black one, and the lens reconstructs where they came from onto your detector. You focus it up, the photon lens, exactly according to what the image was. So you're right, a photon alone contains no image information. You need the ensemble of photons to do so. - Wow. Dude, that was a really good question. - Yeah, I hope he feels good about that. - Yeah, that you should be. I learned something just then. That's really damn cool. - All right. All right, well, last question, as he said. This is Alan Short. - From the Netherlands to Midland, Odessa to Denmark. - Yep, to North East England. - Well, you're gonna love this one. This is Alan Short from Thailand. - Thailand. - No, I'm joking, I'm lying. This is Alan Short. From Italy. - Italy. - Italy. - Van Journal, Alan. He says, "With a profound admiration and the utmost awe of Professor Tyson and HRH Chuck Nice." I don't know what HRH engines. - His Royal Highness? - I'll take it. (laughing) - When he was a kid, when we have juvenile sensing, we say his Royal Highness. - Yeah, I was about to say, and that's, 'cause that's exactly, I was gonna say Royal Highness. - But don't, yeah, we're all hyene. Okay, according to one theory, our universe is located inside of a black hole. If this is the case, where is our universes sing you larity? Likewise, seeing as we have proof that our universe is expanding, why are we not seeing other black holes presumably themselves being self-contained universes expanding and taking over our universe with much love? Thank you. - Alan. - I, Brian Green would be better to answer that, so I'll give it what I can. - Okay. - All right, so a couple of things. - All right. - Some equations related to a black hole apply to our entire universe, such as we have an event horizon. We have a horizon. - Right, we do. - And now it is to event horizon for black hole. - Correct. - If you look at the density of matter in the universe out to that event horizon, it is the density of matter you would need to make a black hole the size of our universe. So there's, but is it a black hole? Okay. And so if it is, then there ought to be a singularity somewhere somewhere. - Somewhere. - And we haven't seen it. - No, we haven't seen it. - No way it is. - Right. Okay. And so. - Unless we're just the information of the black hole. - Ooh. - And so what we're seeing is the holographic information the black hole, the black hole is inside our black hole. - I want more than information. I want to be, I want to be a boy. (laughing) - And it's Italian. That's a Pinocchio reference. - That's Pinocchio reference. - That's my god. - We have done it people. That is how you stick a lamp in it. (laughing) Go to Italy and end up with Pinocchio. - All right. - So that could be just where the analogy breaks between the universe and what a black hole is. - So you have a couple similarities. - But one last point and we'll end on this. - Go ahead. - That the equations of a black hole. And there's a book here that I can dig out that will describe them. And you're, our guy correctly noted that a whole new space time opens up inside the black hole. If you look back at us, the future history of the universe runs its course and a whole other space time opens up. So each black hole would contain a universe. - A universe. - And, but that universe is not sharing the space time of our universe. - Right. - So they're worried with it fill up or bump in. No, in higher dimensions you can fit everything. - Right, and all, yeah it doesn't make a difference. - Yeah, that's right, you can fit it all. - That's so cool. - Just a quick thing, you have a sheet of paper that goes to infinity. - Right. - It's two dimensions. If I go into a third dimension, I can have another sheet of paper that goes to infinity. - And it does not intersect the first. - Exactly. - In fact, I can have an infinite number of - If that sheet's a paper. - If you want to above the other. - Correct. - So when you add higher dimensions, you don't have to think or worry about stepping on each other's toes. - It can happen. - Right. - It's not a thing. - Right. - All right. - I think we got a call and quit their check. - Well that was a good one. - That was a very hot spot. - Yeah, I like it. I like it when they're all over the place. - All over the world. All right, very good. This has been a start talk, Cosmic Queries, Grab Bag Edition. Those are fun. - Yeah. - Love those. Chuck, thanks for doing this. - All right, Neil deGrasse Tyson, your personal astrophysicist reporting from my office at the Hayden Planetarium. As always, keep looking up. (upbeat music) (upbeat music)
Podcast Summary
Key Points:
Time measurement requires repeated motion; without repetition, only event sequences can be tracked.
Space and time are interconnected; space cannot exist independently of time.
Recommended books for a 12-year-old include "Astrophysics for Young People in a Hurry" and "Merlin's Tour of the Universe."
The universe appears the same from any point; our cosmic horizon expands at one light-year per year.
The Silurian hypothesis suggests previous civilizations on Earth are unlikely due to lack of fossil evidence.
Black hole singularities may be mathematical artifacts where general relativity breaks down, requiring quantum physics.
Light transparency depends on atomic structure; light slows in media like diamond, causing refraction.
Mining the moon is unlikely to significantly affect Earth's tides, as lunar mass would largely stay in space.
Summary:
The transcript covers a variety of cosmic and scientific questions. Neil deGrasse Tyson explains that time measurement relies on repeated motion, and space cannot exist without time. For a 12-year-old, he recommends his own books, "Astrophysics for Young People in a Hurry" and "Merlin's Tour of the Universe," for accessible science.
Regarding the universe's edge, he clarifies that from any point, the universe looks the same, and our horizon expands at one light-year per year. The Silurian hypothesis is dismissed because fossil evidence of advanced prior civilizations is absent, though Earth's crust recycling could obscure evidence. Black hole singularities are discussed as mathematical limits of general relativity, potentially resolved by quantum physics.
Transparency in materials is explained by atomic structure affecting light paths, with diamonds slowing light to create brilliance. Finally, mining the moon is considered unlikely to impact Earth's tides significantly, as lunar mass would likely be used in space rather than brought back to Earth.
FAQs
No, the measurement of time requires something that repeats periodically, like a day or a second. Without repeated motion, you can only sequence events, not measure time coherently.
Neil deGrasse Tyson recommends 'Astrophysics for Young People in a Hurry' for ages 8-12, or 'Astrophysics for People in a Hurry' for older readers. He also suggests 'Merlin's Tour of the Universe' for fun.
It looks the same as it does here because everyone sees a horizon around them. You'd see galaxies being born from light emitted 13.8 billion years ago, and the universe likely extends far beyond our visible horizon.
It's very unlikely because we would find fossil evidence, like bones or artifacts, in the Earth's crust. However, subduction can destroy evidence over long timescales, but no such evidence has been found.
They may be mathematical artifacts from general relativity, which breaks down at that point. Quantum physics is needed to fully understand what happens inside a black hole.
Transparent materials have a structure that doesn't alter light's path, so it passes straight through. If light is absorbed or scattered, the material becomes opaque or translucent.
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