Cosmic Queries – Renaming Time

0:00Chuck, 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 gonna 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. Inquiring minds want to know. Here we go. Let's get right into it.

0:47Okay. 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. So where there is no repeated motion, there can be no coherent measure of time.

1:39All you'd be able to do in your own reference frame is sequence events. This came before that, before that. Right. I remember in the before four times. No, the before four, four, four times. Right. I'm older than you. Right. Before, before, before. 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'll 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 with any meaning or repeatability. So that's a great, it's a fun, interesting philosophical question.

2:27Yeah. Yeah. But space can exist without a time, I would think. Space doesn't need time. No, it doesn't. I mean, space is like, I'm here. You know, I'm not going anywhere. You want to measure something? That's your business. That's what you want. I don't care what you measure. I'm right here. So there you go. That's very cool. Well, there you go, Eric44. Why don't I answer that quickly? That was a great one. Wow. Well, we're off like a rocket. This is Maurice Backer. It says, Dear Lord Nice, Dear Dr. Tyson, I am Iliada from the Netherlands, and I am 12. My question is, what is the one book that every 12-year-old should read?

3:13And my name is pronounced Iliada. Okay. Thanks for the phonetic there, Iliada. He knew in advance. Yeah, I called you Iliada, and yada, yada, yada. Anyway. Stop. Stop. No, no. Okay, Elida. And I didn't get it right. She asked, I should read these beforehand. Anyway, universal respect and greetings. Delightful. What a mature 12-year-old. What a very mature 12-year-old. That's clearly not written by an American kid. 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.

4:02All right. Scientific landscape. I say, I'm going to bridge that gap. I'm going to put something there. I'm going to put something there. Right. So I can say at age 12, writing like that, and plus the Dutch, they're fluent in English. Yeah, well. I mean. Yeah, without a doubt. Okay, so. Even though they're frites and purr, they're purr, they're purr, they're purr, they're purr, they're purr, they're purr, they're purr, they're purr. No, that's not Dutch. I know, I know. No, you're mixing that up with the Swedes. With the Swedes, I know. But it's funnier when, you know. Like, Dutch is actually...

4:33That's actually Dutch. But it doesn't make for a funnier, you know. It 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. Well, they got to get back to them video games. You know what I mean? I'll read this real quick because Valorant is waiting. Halo ain't going to play itself. Got to 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.

5:17Oh, wow. Cool. Which collectively is called The Tweens. Right. Right. And its value is, it's not just that it's a dumbed 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. So it might still have value to a precocious 12-year-old. Right. 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.

5:56Right. 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 as a cocktail party. That'll totally equip you to do so. So there's that. But then if it just wants to have fun, definitely the Merlin book. Oh, okay. Merlin's Tour of the Universe. It's a Q &A. He's asking question and 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.

6:37That's great. Yeah, it's not shameless. I'm doing it with complete shame. No, you're doing it with, right. I know what I'm doing. Ain't no shame attached here. 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 Elida a boy's name or a girl's name I don't know I don't know he or she Elida Elida okay let's neutral let's de-genderize it yeah we'll call them they they so Elida sorry to misgender you if 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.

7:20Halo ain't gonna play itself. There you go. All right, here's Andrew Bowen. I'm riding 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. Ooh! We are at the horizon of anybody who's at our horizon. Exactly. And anybody at our horizon just sees the universe all around them like anybody else does. There you go. Yeah. Yep, that's right. So what would happen is if you, 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.

8:21You will see all of us as galaxies being born. Right. So this would be your horizon. That's what it is. That's so cool. We are 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. You go to your horizon, you're still in 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. There might be a point where land shows up no matter how big the ocean is. Right. So there might be a point where you run out of galaxies in the universe.

9:01Out of galaxies and stuff, right. Right. But we don't know that because— 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. But you know what happened? If One day The cosmic microwave background Disappears And that would mean That our horizon Which is expanding At what rate? Well it's gotta be Isn't it faster than the speed of light now? No, just a visual horizon It's expanding at one light year per year 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 disappeared, 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.

9:56There are no galaxies. And we would have reached the edge of any material substance in the universe. Right, because we're... Now, wait, is that because we're traveling? No, no, our horizon is continuing to move outwards. Because it's moving out. It's moving out. It's moving out. So it will always find a galaxy being born. Right. Okay. Until it doesn't. I gotcha. And so, right, once we get past that, that means nothing's there. Nothing's there. Oh, snap. That's finally getting beyond the ocean and land. Right. Yeah. All right. Wow, that was cool.

10:42I'm Jasmine Wilson, and I support StarTalk on Patreon. This is StarTalk with Neil deGrasse Tyson.

10:56So let's go to Young Han. Young Han. Spell Young. Y-O-U-N-G. Okay. Young Han, who says, Mr. Tyson, I love your work and your show. Can you talk about the Silurian 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? Hmm. wouldn't it be fun if we were just the nth intelligence civilization to rise up on planet Earth? Or even the nth civilization of humans that had rose up and destroyed themselves and rose up again multiple times.

11:55So you'd think, I think, we would see a record of this 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 all the hell! You apes!

12:18That's an example of a civilization that predated the planet of the apes, because that was Earth. It seems to me we would find a record of it. 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. Yeah. Running underfoot trying to not get eaten by T-Rex as hors d 'oeuvres. Okay. So you can't presume that there were big brain mammals before that. because that was the origin of the mammals on Earth around that time. Right. Is there a possibility that the civilization before us were not mammalian?

13:10Okay. So I haven't seen any like dinosaur casinos.

13:18I mean, just you would see things. Right. 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 time scale for all of Earth's crust to get subducted back down and come out in a volcano? Oh. Because that would destroy all the evidence. Right. All the evidence would be gone. Because it becomes molten. Completely gone. 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.

13:53Right. Like made yesterday. All of the big island of Hawaii. Iceland is on the mid-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. But still, it's new land compared to other places. You go to places where it's not regenerated that rapidly, and you don't find other evidence. Okay. So, yeah. Yeah, it's very unlikely.

14:32Yeah, 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. I just remember the cartoon Land Before Time. I remember that one. Yeah, Land Before Time. Do I know that one? It's a cartoon movie. I don't think I know that one. Yeah, dinosaurs, it was like... 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 So Corporation. 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 with a pot and go, not the mama, not the mama.

15:13In other words, like, I don't want you. Get me, mom. So this is like the Flintstones, except they're dinosaurs. Yeah, that's it. There's a whole world that they— A whole world just like the Flintstones, but all run by dinosaurs. Okay. It was a pretty wild little show back in the day. Okay. There's the thing about the size of their brains. There's an issue there. Oh, okay. The higher levels of thought. The higher levels of thought might not be resident in a dinosaur whose brain is - It's an 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.

15:49Ooh, 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, Lord Nice. It's James from Denmark. By the way, James, we apologize. Oh. We're so sorry. And, you know, all this talk of Greenland, we have 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 buy Greenland. That's what I think. So I'm sorry. So here's what James says. I heard on a previous episode that what we think of as singularities at the heart of a black hole may not actually exist.

16:42But 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. I love these. Pretty wild. So if you just follow general relativity math, 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.

17:28But 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 volume. Right, and wow. And that's just crazy. What does that even mean? What does it mean? We all presume that there's some other law of physics that's going to prevent that, but that calculation is at 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.

18:05Right. Whereas 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. Because if you do, then you reconcile 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. Okay. Because remember, you're not supposed to - You can't do that, or you're not supposed to do it. You're not supposed to do it. I still don't know why.

18:42I'm just like, you know. Have you tried it? Because 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 from nothing leaves nothing. There you go. That's a good song. Nothing from nothing leaves nothing. 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 that came out. Everybody was high on cocaine. They weren't trying to do math. It's like, who are you trying to impress with this math here? Certainly.

19:12I 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. It 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 not good. Correct. So I'm giving like a just so answer. 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.

19:59Okay. 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. Right. 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. Okay. But here's a little known fact. as this person surely knows light travels slower in a medium than it travels in a vacuum right it 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 when it's cut, when the facets are just right so that's why diamonds have a certain radiance of their own when they're just really messing with the light that came in so Rihanna was wrong It's not shine bright like a diamond.

21:03It's just reflect light like a diamond. What was that from? Ocean's 8? No, she has a song, shine bright like a diamond. Oh, sorry. I didn't know that. It's not shining. It's not shining. Yeah, it's not shining at all. Right. Yeah. Is that why they put her in Ocean's 8? Probably. And that, and she's Rihanna.

21:23Okay. Okay, couple more. Go. All right, here we go. Alex Romillion says this. Greetings, Dr. Tyson and your ragtag 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 it 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 in.

22:05Yes. Okay. A couple of things. A 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. That we want to bring it back to Earth. Especially since the moon was carved out of our crust in a collision between a Mars-sized protoplanet and Earth. It sideswipes up. Our crust goes into orbit, coalesces to form the moon. Right. And so the moon is our crust. That's probably not too valuable. No, it's not too valuable.

22:45Not too valuable. Yeah. To go there and then bring it back. So now, but suppose we did. Okay. Suppose we mined 100 % of the moon. All right. Put 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. Sun tides are about a third as strong as the moon tides. Right. 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 the one I do. That ain't. Shh.

23:24That ain't doing nothing. That's a mosquito. Like, so if you weigh 100. A mosquito on an elephant. So if you weigh, so 100 pounds on earth, you'd weigh 101 pounds and a little, and change. I don't know. That's barely worth it. And you fluctuate that. That's not worth the trip. Between meals and between poop. Right. Okay, you fluctuate. Yeah, that happens to me every morning. You know what I mean? Get up on the scale like, damn. Go to the bathroom. All right.

23:56so yeah it's not don't worry about it yeah yeah it's it's a big moon but earth is even bigger there you go we good

24:21All 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 isn't absolute. It's relative and experienced 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? Would 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.

25:04I don't have more time for this, Mr. Usterweil. Okay. I have one answer. It's a cool little thing that he's positing. Time has one syllable. Exactly. And what he read there, count the syllables. Count the syllables. Observer relative perception of reality. a T. It's 14 syllables. Time has one syllable. Right, exactly. So take that word and make it mean what we want it to mean. And 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.

25:51For example, our words that describe the sun and the horizon are pre-Copernican. I don't say to you, Chuck, at what time does Earth rotate such that our sight line to the horizon reveals the sun sitting out there in space? Instead, I say, when does sunrise? When does sun rise? And when sunset. And when sunset. All 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. 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.

26:32And Zach says, hello, Dr. Tyson, Lord Nice. Zach here from Moonsville, New York, or Munnsville, 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? Oh, I like that. Thanks in 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. So matter can make black holes where you're compressing things down into one place.