Answering Questions About Time Travel, Aliens & Negative Gravity

0:00 If you were a life form on a pristine planet, what is the first question you would ask exploratory humans? So, first let me say go to an old episode of the Twilight Zone called The Invaders. In that episode, Agnes Morhead is this lone ranch woman on a little house in the prairie and you just have to watch that. It's called The Invaders. Point is, if I'm the other life form and I see humans, my first question would be, have you come to colonize this planet? Cuz if that's your goal, that's not happening. Okay? This is Star Talk. Neil deGrasse Tyson

0:45 here, your personal astrophysicist. We're going to do cosmic queries today except today I have Paul Mccurio. Paul, what's up my friend? Welcome back to Star Talk. Great to see you. What'd you do with Chuck? What did you do? What' you do? Uh, you know, he's in a bag somewhere. He's he's Last time Chuck He was breathing. He was still still breathing. So, how you been, man? I'm good. I'm good. I miss you. I miss you. Still doing the the late show. Doing the late show with Stephen Coar. Just did another appearance on that. I've been touring with my Broadway show, Permission to Speak, directed by Frank Oz. Frank Oz. He's the the voice of Yoda. He's Yoda. He's a mench, as they say. He's a great He's just a brilliant artist. We love him. We love him. Yeah. And he's been on our show. You can find him in our archives. Oh, he's he's amazing. And he's just And you'll see all how the breadth and depth of all that he is. Oh, the Muppet creator with

1:33 Jim Henson of the Mupp. He created Miss Piggy and Fuzzy Bear. Directed everybody from Marlon Brando to Robert Dairo to me. I don't know what that's about. He's really a step down. I think he's living in his car by the river. We love. So, this is a grab bag. There's a grab bag. We love these. And I haven't seen them before. If I don't know the answer, I'll just say I don't know. Yeah. Oh, you know, you always answers. No. Okay, here we go. Eric Krajidoti, Dr. Tyson, and Duke Mccuria. Wow. I've never been called a Duke before. Oh, cuz Oh, cuz Chuck is called Lord. Oh, Lord. Nice. Oh, I didn't Oh, okay. Okay. Well, everybody's got a title. I'm a Duke now. There we go. I hope that Matt is at home with my wife. But are you Duke of Earl?

2:18 What are you Duke of Earl? All right, go lower. Duke. Duke. Yo, you can do that. I can do We're going to just do this for 30 minutes. Duke of Then you got to come in high. Give me some falsetto. We'll find out what you're dook of. We'll come up with something. All right. Go. Greetings from Mangahila, Pennsylvania. Regarding the idea of time travel in star position, hypothetically, if I were to create a time machine, attempt to go back to Mangahila 2,000 years ago, would I not end up in empty space because the entire solar system would not have arrived in that location had I departed that I would have departed from? Every time machine is

3:03 also a space machine. They're space-time machine. They don't say it, but they have to be. Why is that relevant? Why does that matter? They have to be. Now, they got around that in Back to the Future because when Marty is trying to escape from the Libyan terrorists, and he jumps in the Delorean and he's quickly typing the date, he types 1955, but it's the same day of the year as he leaves. So, he goes back to 1955. Earth is in the same part of its orbit on that date around the sun because of the date the date the date was the same. So so they skirted but that can't be true because hang on. So that they dodged that bullet a little bit. Okay. Had it been 6 months earlier

3:50 or later he just be plopped in the vacuum of space and he'd be dead. Okay. So the the reason why they dodged that bullet is because the entire solar system is also orbiting the center of the galaxy. So it happened to pick the exact date. That was the key there. Well, only for the moving coordinate system that is the solar system. Okay. But because the whole solar system is moving, he goes back 30 years. He's leaving our solar system today. And if he only moved in time, he would be where our solar system is today 30 years ago. But he also he would been well ahead of where the solar system would have gotten. the soul would need another 30 years to catch up, but he also moved in space is your point, not just in time, which is why he landed in exactly the same spot on Earth. So,

4:36 so it's implicit in the storytelling. So, you're absolutely right. Nothing you can't do that in any way. That makes sense. But wait, if our solar system formed about 4.6 six billion years ago. Isn't the premise part of his question has a false premise which is I would not end up because the entire solar system would not have arrived in the location solar system is there in that location. No, no, no, no, no. We're in a rotating galaxy. The Milky Way is rotating and so that is all the stars in the Milky Way are rotating around our central black hole in the center. So if you go back in time, if you go back in time, you are no longer where you left in space and you'll be dropped in the

5:21 middle of nowhere. So you you always have to land in a space-time coordinate in the future. We sort of do that, but without the relativity part, if you're going to visit Mars, you don't aim for where Mars is. You aim for where Mars will be when you get there. Then you intersect Mars. So, if you're going back 2,000 years, it will be an empty Well, there's going to be a Home Depot cuz they existed in a Subway sandwich shop. They they've been around and in the mall. Yeah. Well, I mean, you know, their franchising methodologies are brilliant and they never get enough credit. What what what you need is you have to know where was the solar system and the earth 2,000 years ago and not only move back in time, but move back to that location. But you cannot say that the manga would not be the manga 2,000

6:07 years ago. Why wouldn't it be? Why would not it be exactly what it is today? The mangahila sounds like native a native tribe. It is. That's who would be there 2000 years ago. But he's asking if I create a time machine to go back to mangahila, would I not end up in an empty space? Yes, he would. Unless he moved in time. That's I've been spend 10 minutes describing. I understand that. So your answer, you answered his question is yes. Yes. Unless he also moves back in in space base as well. Correct. Got it. Okay. And yes. So every time machine is also a space machine. Otherwise, it would be quite lethal most of the time. What would happen? No, you get dropped in the middle of space cuz everything's moving. You got to move with the action. Okay.

6:53 Marggo Lane. Mhm. If you were a life form on a pristine planet watching exploratory humans arrive for the first time. Okay. So, you're observing humans arrive for the first time. Yes. What is the first question you'd ask them, assuming you could understand each other? And I have the answer to this. My question would be really you needed Sketcher shoes where you don't have to bend over to put them on. That's where you were. I bet you saw our TV commercials that forget about that. That's where we are as a species. There's a lot of questions. The Kardashians. What? Why? Really? What's up with that? Right. How do people who make Vaseline make any money? Think about it. I've had the same tub of Vaseline. My Vaseline was handed down to me by my grandfather in a will. I don't think you understand these conceptual these Okay, here we go. So, I think

7:38 people used to use Vaseline before lotion was big. I use it to grease the brakes on my car and I still have a giant bat of it. Tubs of Vaseline are not as You know, you could go through 30,000 bags of garbage. You're not going to find one empty container of All right. So, if you were a life form on a pristine planet watching exploratory humans arrive, what is the first question you would ask exploratory humans? Okay. So, first let me say that you should look online, maybe Pluto TV or one of these things that has old TV in it. M TV. M TV. Yeah. But and there's several others as well. Go to an old episode of the Twilight Zone called The Invaders. That's all I will say. Well, I watch a lot of Twilight Zone. I'm trying to remember which one that is. So, uh,

8:25 in that episode, Agnes Morehead is this lone ranch woman on a little house in the prairie and the whole it's a one woman show. She's the only character in it and you just have to watch that. It's called The Invaders. Oh, I do remember this now. It's called The Invaders. Don't say anything about it. Point is, if I'm the other life form and I see humans, my first question would be, just given what I know about humans, have you come to colonize this planet? Cuz if that's your goal, that's not happening. Okay? That we will not let that happen. Okay? Because we've seen what happens when you colonize stuff before. Okay? Uh so that's the first point.

9:11 Second, I That's interesting because that that implies that the humans have more technology than the alien in that case. Yeah, because otherwise the aliens would have visited us first. No, that's you're just jumping the conclusions. Wow, you're missing it. The question you got to ask is really you conveyed happiness by a little yellow circle with a smiley face called an emoji. Like there are so many bigger questions that you could ask these people. Yeah. No, the colonization is a good point because nothing good ever really happened from that. It's good and how about this? I would say how did you survive yourselves, wouldn't enough, right, to then come visit another planet. That's maybe what you would do is you would be hiding behind something and you' say, "How do you feel about brothers?"

9:57 You know, you got to ask this black question cuz you know cuz if they're not with the thing. No, maybe you just say, "What part of the are you from?" Oh, I see. Yeah. What part of the the demographic? Well, if you see them goostepping down toward you, you probably know if you're a Jew or a black person. H you may want to let them just pass. Or gypsies or Catholics or Catholic or pretty much anybody. Yeah. Yeah. Anyone non Aryan? Wouldn't you ask them how you got there, though? Seriously, what was your technology that got you to us? I assume they would see them land in something. No. No. But but you'd want to learn from As a scientist, I would compare notes. Yeah. And I would do things. There's certain things that should be common between us even if we don't otherwise speak the same thing you call tang like that kind of thing. So

10:44 but how would I know that though? That's what I'm saying. I don't know the tang or the Kardashians or slip-on sketchers. I don't I don't unless he shows up drinking Tang. Do you have to ruin every joke and party with your stupid logic with a Kardashian underarm and slip-on sketchers? Then I could ask what's up with that? Why can't you presume that this this life form is smarter and has the ability to see what we've been doing? Here's what I would say. I want to know I want to compare science notes because science transcends time and space in ways culture does not. But it doesn't transcend Instagram. If you got a big following, it's all that matters. So, if I I'd verify that they can see in the same wavelengths of light that I can see, they could have completely

11:30 different senses. Well, I was going to think say medically you'd probably want to check each other out, too, right? Not first. No, no, I don't mean poking their bodies first. No, I didn't mean it in that way. What? No, I'm not talking about like anal probes or anything. I'm just saying you thought of that. Don't give the alien a bad name now. No, I'm saying no. Why wouldn't if you want to check out their mind and compare notes in terms of science, wouldn't you physic I would physically want to understand their bodies versus visa v my vessel their vessel and no ser. If I were a biologist yes but I'm a physicist so no I compare I I pull out a periodic table of the elements. Mhm. Because that organization is universal anyone who knows the elements well enough as well as we do would organize them that way. Okay. But what if somebody that landed

12:16 was like a write a a creative writing major and didn't care about science. If they were the first emissary to another planet, I'm pretty sure they would have given them some science. Yeah, you're just a science snob. Oh, only we're the ones that everybody cares about. Hello, Neil and Paul. This is Julian, Atlanta native, writing from downtown Manhattan. My question relates to stars and black holes. I understand that our sun belongs to the third generation of stars since the Big Bang. Each star will eventually die out in an explosion, some of which form black holes, ending in eternal singularity of their mass. Is it possible that in the distant future there will be more black holes than stars since their lifespan is so much longer than that of a star? Could the passage of time create a population of black holes that outlive and nearly

13:02 replace stars? Yes, next question. Okay, that was a So, it turns out according to Stephen Hawking, black holes actually evaporate, but very very very slowly. So, it's not burnout, it's evaporate. It's a different It's a different Yeah, they wouldn't burn out. Very very very slowly. So, there's a point where all the stars burn out and they they leave their corpses. Some of those corpses are black holes and there will come a time when the black hole black holes outnumber the living stars. They will never outnumber the corpses. But isn't the black hole then like it's like the Alice in the Brady Bunch with a giant vacuum cleaner. It's like sucking up all of the stars that whether they evaporate or not. I don't Alice in the Brady Bunch. Yeah. The housekeeper. Is that

13:47 what she did? She was She would vacuum the black holes. Yeah. I'm sorry. I can't connect. I'm sorry. But do you see where was Alice in the grid of nine squares? She was in the center. She was in the center. And if you notice, her image kept uh repeating back and forth because they didn't have the technology. It was a pretty short loop, right? And I got annoyed by it. It's the same thing in the Mad Mad Mad Mad World. Yeah. Um I just saw it last night. Really? No, I'm serious. Okay, I know every of that movie. Okay, so there's the shot when at the end Spencer Tracy is hanging on to the edge of uh he slides down a a cable and goes through a window and is sitting there and a great Dne is licking his face. Yes. And that's to repeat it. Keep it. And it's to repeat it. And it was annoying me as

14:32 well. I don't know how he got off on that, but it's like and and he's doing this with his eyes move the same way. Um, but is it possible there already more black holes in this than stars in the un our universe? No, because we know who who the progenitor is of a black hole and it's a star that's made one out of 10,000 stars or one in a million star. It's it's the most massive of stars is a black hole. And in any volume of gas that creates stars, it creates a lot of low mass stars and fewer middle mass stars and very few high mass stars. So is this like a cosmic game of hideand-seek? It's it's it's called the initial mass function specifically. And the initial mass function favors low

15:19 mass stars and high mass stars are just rare rare. And I I don't know the latest iteration on the initial mass function, but it's at least as rare as one in a thousand stars that what what are massive enough to make a black hole at the end of its life. So all I'm saying is we have stars today that are born out of these pockets of gas that are still alive and thriving and would have only had one or two black holes. So no, black holes do not outnumber stars. By the way, they will outnumber stars in a trillion years. A few trillion years when the lowest mass stars burn out their fuel. It just sounds like stars need like a support group for black holes in the way they get dealt with. No, they'll be fine. Black holes need no support. The more black holes that

16:05 develop, we're all in jeopardy. No, I just avoid them, that's all. Well, but what you do emotionally in your relationship to other people is not what's relevant here. Yeah. We just need a map of where all the black holes are and then step around them. Especially in your time machine. You don't want your time machine to land in a black hole because you didn't type in the right space-time coordinate. All right, let's move on. I think we answered that thoroughly. Mhm. Cesar Fredik from Bogota, Columbia. Love it. Uh, speed of light C shapes our reality and its fundamental properties. However, it is intriguing to consider that regardless of the unit used, C could potentially be half, double, or any other value. Could you suggest factors other than the possibility of it being

16:52 an imposed constraint with it within a simulation that might determine the seemingly arbitrary value of this universal constant as we understand it? Wow. Here's a couple of speed of life facts. 299,792 440 meters/s. Yes. Yes. And do you know where the C comes from? The Latin word speed. C stands for constant. Yeah. But they think that but there's a speculation from a 1922 uh historian and scientist that it's celitrius, the Latin for speed. That's the first I've heard of that. Well, that's why I'm here to open your horizon. That's the first I've heard of that. It's true. First I've

17:37 heard of that. That doesn't mean it's not it's it's the most fundamental constant in the universe, right? And the word constant begins with a C. I understand. But there's So I if I'm wrong, I'd be intrigued to learn that that's what was really going on. Okay. It's not just an after the-act suggestion. Okay. So the units are arbitrary. Completely arbitrary. You said you're How tall are you? 5'9. Mhm. If I measured your height in units of 59ness, then how tall are you? Those unit those number of units of 59. If I have a new unit that's 5'9 in I'm one unit. You're one. Okay. So your point being that doesn't make you shorter or taller or anything, but your point I'm saying that the units

18:22 are arbitrary, but the speed that we're measuring is not. That is real and it's fundamental. So the units don't matter. And so precisely do we understand the speed of light. It's been measured so precisely that it defines the length of the meter. That's how well we know the speed of light. So if we get another point of precision in the measurement of the speed of light, it affects the definition of the length of the meter. So you can v you can vary that well only in the points where it's still uncertain. That's correct. But it's the most amazing fundamental thing there is. So there is no inherent there cannot be any inherent uncertainty around the

19:08 speed of light is what you're saying. Whatever uncertainty there is, it's smaller than our capacity to measure it. Then how do you know that there is uncertainty if you can't measure it? There is always uncertainty in every measurement. How do we know that? Always. How do we know that? Say, so how tall are you again? 5'9. Are you 5'9 and a quarter? Are you 5'8 and 3/4? Are you 5'8 and 7/8? Are you 5'9 and 1/8? You 5'9 and 1/16th? How come you gave it to me in units of inches? You've approximated, haven't you? Well, it depends on what socks I'm wearing. You have approximated it. So now I measure it 5'9. Let's say you're exactly 5'9, 5'9 in. What does that even mean? the thickness of the line. That's the nine

19:54 inches above the five feet. Where are you within the thickness of that line? Right. Are you 5'8 and 9900s of an inch? Are you 5'9 and 1/ 1,000th of an inch? So, you're saying exactitude is impossible. Correct. Always everywhere. You can never measure something exactly. Is that because of the spa space-time continuum? No, it's it's they're what's called measurement errors, but they're not errors. They're just measurement uncertainties. So if you were once 5'8 and then you're later on 5'10", there was a point in your life where you were exactly 5'9", but you could have never measured it to be so. Right? All you could do is measure it and bracket it according to the uncertainties of your measuring device. Right now I'm exactly 5'9. I

20:42 felt it with a little vibration. Little vibration. So measurements are never exact and they never can be and they never will be. That's correct. You can only know them with greater precision. And you're how tall? At my tallest 6'2, but you're shrinking. Yeah, I'm probably shrinking. Is that your spine collapsing? The the discs between your spine and column fluid. Yeah. But you can go into space and grow an inch or so. But your space suit that you walk in in the spacew walk is made taller than the one you took off in. Why are we growing? Because gravity gravity is no longer squashing you. So the atoms are getting stretched. Yeah, the molecules stretches out, right? So I'm probably 61 and 3/4 now. I'd guess you are, as they say in science, a tall drink of water.

21:29 All right, here we go. Doesn't that mean you have great affection for me? Knows no bounds. It's boundless. All right, Stephan Summers. Uh this is Steph from H, Kansas. I was m making my way through your old small towns. I love it. Yeah. making my way through your old queries and found one where you talked about how if we could pass through wormholes then gravity would as well. But my understanding is that gravity is the warping of space and since a wormhole is making a hole through the dimension of space would it be warped on the other side? Furthermore, if a wormhole is a literal hole through a dimension, would we be able to pass through it or even perceive it as being uh as beings who live within

22:15 our threedimensional space? Wow. You want me to That sounds like he wants to write another the sequel to say, do you want me to repeat anything? No, no, no, no, no. He wants to write the sequel to Interstellar. That's what he's trying to do there. That's exactly. So a wormhole uses, if we were to make one, uses negative gravity. So we know how to make a wormhole. We just don't have the sub the stuff, the substance to make it happen. Gravity collapses spaceime on itself. Negative gravity, if we could negative matter, would pry open spaceime and creates a shortcut through. So if we did that, we in principle should be able to position it in such a way that pops a hole through the fabric of space and time and you step through

23:01 and you're instantly on the other side, which by the way would have rendered transporters completely obsolete in Star Trek. Think about it. Just step through a wormhole to get down to the planet. Yeah, but there's no guarantee you're going to get through without getting lost. It's like Google Maps and you take a right and then suddenly you're in a corn field. I'll take that chance because you don't pay attention to Google Maps. I'll take that chance over dematerializing my body into energy and rematerializing it back into matter on the other side. Why do you think that that's not pos? Because your like your nose ends up on your cheek. Anything. Anything. My thoughts, my memories stored in the synapses of my brain. I don't know what's going to do that. No. Maybe you could help. Let's say you misplace your keys all the time. Suddenly things are rearranged. you know

23:48 it all the time. That's a possibility. But the brain is so complex, I'm guessing that if you dematerialize it and rematerialize it, chances are you'll mess it up rather than improve it. Okay, but if we're 3D and a wormhole is in another dimension, how do we even know it's there? It's like trying to change a flat, not knowing where the car is. We see the part of the wormhole that intersects our dimensionality, but it's only part of the wormhole. Well, so here's an example I gave in another show. Uh if we live in a flat sheet of paper and then we're just standing around and we see a dot just appear out of nowhere. That dot becomes a small circle and then a big circle. We're just watching this. Okay. And then it shrinks back again, becomes a dot and then disappears. That'd be freaky. No, that's

24:35 called a Vegas act. It's a magi. It's a magician. He works at the completely freaky. Bellagio. What you just witnessed was a three-dimensional sphere passing through the two dimensions of your world. And you described it as a point and then circles that grew until the circle was as wide as the diameter of this sphere and then it went back and then disappeared as it passed through to the other side. So higher dimensional things passing through our dimensionality will manifest in some way or another. So in answering this question then the answer is uh if a wormhole is a literal hole through a dimension will we be able to pass through it or even perceive it as being as beings who live uh within our three

25:20 dimensions. Yeah, you can perceive you would see the part of the wormhole that intersected our dimensionality, but nothing more than that. You won't appreciate all of what else is going on there. The fact that it moves into a fourth dimension, you're not going to catch that. But if you're passing through a wormhole, you're going to instantly get to the other side instantly. instantly. So what movies like showing that you're going through this tunnel, you know, it's like in the in the water park. No, it's it's correctly done in Rick and Morty, which is exactly why I watch Rick and Morty for my science knowledge. And this dude, what's his name? Doctor Strange. You know what I'm talking about. He's I would if I had a superpower. I just would want to be able to do that. It's a very sophisticated, understated. It's

26:06 not this. It's not trying too hard. It's like, yeah. Yeah. I mean, I prefer the Rick and Morty wormholes because Rick uses real science. And what is it about that wormhole and Rick and Morty that's accurate to you? No, he just uses real science. Whereas Doctor Strange uses magic? If you can't perceive a wormhole, aren't we in a way like walking through life like this tourists at a loss in New York City just looking up, taking pictures at everything? Yes. And isn't there a way that science can sort of make us not feel that way? Deal with it. You can't become a scientist unless you are comfortable being steeped in ignorance. Okay. So, we have this constant debate. This is where you just like try to get off on being lazy and not trying to get stuff right.

26:51 No, I want to get stuff right. Oh, it's better to not know anything. All right, let's go have a bottle of wine. No, it's learn to love the questions themselves. Oh my god, I went through law school. I don't need this. Aida answer a freaking question, will you? You know, talking to you about science is like looking at a Picasso and then you're like, whoa, why is the nose on his calf? I don't know. And then some some historian, art historian has a theory and they're completely full of you know what. Okay. You know what? You're fired from science. I don't think he ever put his nose on his calf. Yes, he did. All right. Here we go. Oh, this is Captain Carl with two K's, everybody. Ohoy. Captain Carl from St. Thomas, US Virgin Islands. I've often wondered as a photographer and as physics enthusiasts, is our colorful world a result of our white star? White being made up of all

27:38 colors? What if our planet or any planet was orbiting a blue or red star? Would our world be different shades of red or blue? By the way, I just want to thank you, Neil, and shout out to your comedic sidekicks. Uh, so would would our worlds be different shades of red or blue if we're orbiting a blue or red star with our current eyes? Yes. But if we evolved there, there's no reason why our evolutionary path wouldn't have taken divided up the the blue light into different subcategories. Yeah. But if you have pure red, then entire earth's going to feel like a brothel. Yeah. However, don't pretend you don't know what that is. The width of our sensitivity to light is much greater than any single band of light. Say that again. You lost me. All right. So, you have Roy G. Biv. Do you know Roy G. Biv? You don't

28:26 know Roy? Red, orange, yellow, green, blue, indigo, violet. Roy G. Biv. Okay. You You never knew that. No, I never. No. You got to learn something every day. Yeah. That's why I'm here. Okay. Okay. Roy G. Biv. We see all those colors. Now, when we make color photos by Hubble or the James Webb telescope in the infrared part of the spectrum, you can't see colors in the infrared part of the spectrum. So, you know what we do? We take RGB, slap it onto different wavelengths in the infrared part of the spectrum and create a color photograph out of it. That's what you would see if our site was shifted to the infrared part of the spectrum. It's what the world would look like. So the infrared part of the spectrum, is it neutral in color? You

29:13 can't detect it at all. But if we evolved to see it, there's no reason to think our brain wouldn't assign colors to it. That's what's going on here. We're assigning colors. In fact, Richard Dawkins, the evolutionary biologist, thinks that bats actually when they echolocate, they see in color because their mammal brain has that capacity. So why not use it? So when you're using echolocation, tag it with a color. So if we orbited if we orbited a blue star, we'd still have would we still have clear skies? In other words, every if if our eyes evolved in this star and then transport us to a blue star, right? Then we would not see colors in the blue because we

30:00 can only see colors in the visible part of the spectrum. There'll be blue and ultra violet ultraviolet. We only see colors in the visible part of the spectrum. However, you can fake it authentically fake it. That's called the perfect Instagram filter, right? So going in that direction, we have violet. Take three bands in violet light that are adjacent to one another. Then once you do that, you you assign RGB. Bring them back together and you can reconstruct what you would see if our sensitivity were shifted to the violet and ultraviolet part of the spectrum to the blue part of the spectrum. So we should think of it as shifted color is what it is. But we only limited in how much we can our abilities

30:45 to shift. We're very limited. Well, you are. I'm not. So, we see red through violet. That's it. And that's if I want to see color anywhere else, you take out the RGB, slap it down on three different bands, and out comes a color picture of X-rays, of infrared, of ultraviolet, of of gamma rays, all the above. And so a red planet, a blue planet, a red star, a blue star. Is there any star with a color that you have the ability to see without sort of slapping RB that doing that technique? RBG Roy. Say it. Roy G. Bib. Roy G. Bib. So no, just the way we evolved, we can't

31:31 we can't see into it. So by the way, this band of visible light is very narrow compared with ultraviolet or infrared. very narrow. So, we're practically blind no matter what. And insects see into the deep ultraviolet insects and they're perfectly happy. When I stare into a very bright light and then I can't see for a second what's happening. That's a different thing. You you burn you you over stimulate the retinal cells and they have they have to recover. Yeah. Which takes several seconds. Yeah. Yeah. Yeah. Which is always fun by the way after you've been drinking. Uh, all right. Another question. Hello, I'm John May Huoi. Uh, May Hoy Mayoy. There you go. Uh, and from Parkland, Florida. I know

32:16 that the cosmic microwave background is like a snapshot of the early universe and its temperature has been dropping ever since. So, I'm wondering, could this temperature be used as a kind of universal clock? If we could measure it super accurately, would that tell us exactly how old the universe is right now? Would that age be the same no matter what where you are in the universe? Yes. Because every part of the universe was in the same place at the same time 13.8 billion years ago. So the oldest things in the universe in every direction you look are exactly the same age traceable to that period of time. So yeah, everything now at this moment we see in the past. So we

33:03 can ask what is that thing doing now? Well, it's even farther away from us. It's and we can think of the diameter of the universe as how big the universe is today even though we can't see that. And that diameter is coming in at 96 something like that billion miles full diameter. So if you could see those galaxies at a horizon today, that's what they look like. But that would need an infinite speed of light. And that's I'm not we're not giving you that. Why? Not possible. I'm not giving it to you. Observational limits on the universe. And temperature is the only way to measure this is to have a universal clock is temperature also works. Yeah. So as the universe grows, the

33:48 temperature cools. So it's a it's a onetoone correspondence. So you can just back extrapolate to the early universe. So there's a murder scene. Um and they do a forensic. Why are you so morbid? Well, because that's how I my brain thinks. Uh and they and they and so they can figure out based on the temperature of the body when the body died. Yes. So that's what's happening there. I hadn't thought about it that way, but that's that works. Yeah. You got the crusty old cop and then you got the you got the the sexy sidekick. That's right. Male or female? I haven't thought about that. Well, that's why I'm here. What's the next question? Okay, this is uh Joe Lero Liperella from uh Pennsylvania. Relativity tells us that as an object approaches the speed of light or is in a deep gravitational well, time slows to a stop relative to other observers. My

34:34 question is, what is on the other side of that extreme? If an object is motionless and if there is zero gravitational effect on it, how would time work for that object? There's zero gravity then time goes fast for it. Well, an object is motionless and if there's zero gravitational effect on it, right? So, how would time work? When you are in the presence of gravity, you age slower. So, this is like the ultimate anti-aging hack. This is we should bottle this. We should be on QVC right now, not on this dog and pony show you call Star Talk. We could be making some big bucks. start our own our own QVC channel. Yeah. Dr. Tyson's QVC hack. So, what are they

35:21 asking then? Is is they're asking my question is what is on the other side of that extreme? In other words, relativity tells us that as an object approaches the speed of light or is in a deep gravitational well, time slows to a stop. Okay. So, now watch. So, some years ago, people realized you couldn't accelerate past the speed of light. But does that preclude a particle existing faster than light? If you can't accelerate past it, can you exist on the other side? And serious thought was given to that to the point where there's some movies based on it. And we there's a hypothetical particle that has these properties. It's called a tachion. Takios from the Greek meaning fast. Tachios. Tachons. And Tachons would live

36:08 backwards in time. How is that possible? Because if time slows down as you reach the speed of light on the other side of speed of light, if you continue the equations jumping that gap, time would go backwards for it. Heck yeah. For it for Yes. Yeah. For it. Do we know they exist? No, we never never found them. So then how could you have a theory about something that should because it's allowed to exist by Einstein's equations. And if something is allowed, that's good enough reason to go out and look for it. if other parts. But at one point do you stop looking in all seriousness and go this doesn't if you can't find it. Welcome to the frontier of science. No, it's like I can't find my phone in my house. I'm not going to keep looking. Go, I know it's there. We don't know. That's right. It's a mystery. But if you give up and someone

36:54 else finds it a month later. So when time meets an object with no gravity and no movement, it's like my lazy good for nothing 15-year-old son who won't mow the lawn, right? He just lays just sits there. So the answer to the question is yes on some is it or is it that clear? The answer is wait wasn't there two parts of that. Yeah. There's the uh an object approaches the speed of light is in a deep gravitational well time slows to a stop. Yes. In a deep gravitational well. Yes. Time slows. Okay. Correct. And what is on the other side of that extreme and that would be techons. Techons which we are know there but we haven't found them. Okay. Correct. Got it. The techons work in the equations. So as if as a result and so we're saying well write all these other ways maybe this prediction of the equation should

37:39 work as well. Got it. So if you are motionless in space as far as you're concerned you'll still have your own timeline and all that matters is what other people will say of you as they fly by you. So everyone will have a different time reference for you. All you care about is your own clock and your own wristwatch and your own clock on the wall. And that's all you care about. Now that's if you're not moving. But if there's no gravity, then time speeds up for you. So if an object is motionless and there's zero gravitational effect, how would time work for that object? This is where we're talking it's so this is where we were joking about gravit anti-aging hack. Right. So in other words, you there'd be no aging because

38:26 time there's right there's zero gravitational effect. Yeah. But you and everyone else around you in your same reference frame will age at exactly the same rate. It could be 1 second for every 10 seconds outside of your club. Right. Right. But it won't matter to any of you. You can't hack that system and say, "I want to go back to when I was younger." Okay. But if you're so smart, tell me who in that group is going to get plastic surgery first to avoid the aging process. Yeah. Plus, if you're in space with zero G, some surgeries aren't necessary. No. Well, yeah, it's right because you got nothing pulling on you. Have nothing pulling on you. Stuff floats. That's what we should invent. We should invent people zero G facial surgery. I like

39:13 this question. It's very simple, straightforward, but interesting. Dennis Albertie, please explain buoyancy. Buoyancy. I love it. All right. So, it's all about density. In the end of the day, it's about density and gravity, you know. So if you are and gravity, yes, if you are less dense than the medium you're immersed in, you will float to the top. It's that simple. It's not more complicated than that. Define density. It's how much matter you can cram into a certain volume. So the big advance, it's amazing this didn't happen until the 19th century, was there was some early variance in the 18th century, but it really took off in the 19th century. the fact that you could float metal. If you

39:58 make a boat out of metal, then it's almost impervious to war, not icebergs and a billion dollar gross at the movies. It's exactly what Titanic did, but probably up to two or three billion now. Look, to summarize it, a submarine is a boat in denial. Well, so here's what happens. So, you should react to that. That was a good line. So a submarine is a boat in denial. So if you have a hole that's made of metal, any bits of that metal would just sink to the bottom. However, if it's in the hole shape, it's pressing down on the water. The water is rising up and you've created an environment that on average is less dense than water and so

40:44 therefore it floats because of the V-shaped because most of the volume is air. So you get to add the air plus the metal as part of the contents that's within within the volume. And when you do that, you systematically reduce the density of the material. If you go back a thousand years ago, people made boats out of wood sensibly because wood floats. So you make anything out of wood, it would float. That made complete sense. But you're susceptible to attack. But if I took a metal plank, a a a 4 by 12 piece of metal flat and threw it in the water, would that sink? Yes. Because you don't have that Vshape. You don't have the the rel the relation to air

41:32 because it's all about volume. It's all about volume. So if you if you carve it into a volume, then it's the mass of the shell divided by the full volume of the whole thing. And that gets very low, it' be lower than water. It'll just float. It's the same principle why an iceberg can float because you've icebergs are just simply less dense than water, right? Simply less dense. So you don't need that Vshape for that to for an iceberg. No. No. No. I mean, you don't you don't ever need a Vshape except that I mean, like styrofoam will make a boat, but it doesn't need a Vshape, right? These shapes are important if you know the material you're working with is heavier than than the stuff itself. Right. Because you're display you want to displace. Correct. Right. It's all about displacement. Correct. So the bottom

42:19 line is um icebergs float. You got a V-shaped hull, steel float. Yes. Styrofoam cooler. Best scenario. You can sit on it and tap in and get a couple of beers at the same time. At the same time. Okay. That's why I'm here. Paul got time for one more. One more. Got it. Okay. This is a this is actually a very interesting one. Terry Burke from St. Louis. My question is simple. In nuclear fision and fusion, a small amount of matter is lost and converted to a large amount of energy. Is the gravity associated with the lost mass also lost? No. Because great question by the way. Gravity emanates not only from mass but also from energy because mass and energy are the same thing. Different sides of the same coin. So you're not just losing

43:05 mass and not energy. You're losing some combination of the two and they go hand in hand. So the answer is no. Is the gravity associated with the loss? No. And that can never vary. I mean this is this is a con this is a constant. This can never this the idea that that gravity associated with the lost mass is also lost. Oh matter and energy are one in the same thing. Mhm. So they each distort the fabric of space and time. And that's all you need to know about it. Okay. Mhm. We will commonly think of matter distorting space, but if there's energy there, it will distort space as well. And equals MC² reminds us that they're two sides of the same coin. The the more the amount of energy is created is is the same amount of gravity lost. In other words, like the mass lost is

43:53 gravity associated with the lost mass is also lost. Do you lose more gravity the more energy that's created if it leaves the system? Yes, you're losing you're losing gravity anytime any matter or energy leaves the system. No, I know. But doesn't it sort of all change over time and you know depending on the amount of energy that's created the more energy that created the more gravity is lost. No. Yes. But the it's a lot of energy and a very small amount of mass. So I wouldn't lose sleep over it. Well, listen. It's up to me what I lose sleep over. Just because you walk through life not caring about science the way I do, I can't. It is weird though that humans for onethird of a rotation of the earth are semicomaos. One last question. I'll do it. Quick

44:39 one. Okay. Okay. Uh Mc Mark, I used to have a bell here. I don't know what I did with it. Mark from Portland, Oregon. Is our solar system comprised of remnants from a single supernova or a collection of many? If many, I'm curious how are or any galaxy diffuses multiple supernovas together. Okay, so first a supernova is a huge explosion and its guts are just scattered everywhere. Just start with that. Then the galaxy rotates as we say differentially. So the inner parts complete a circle faster than the outer parts. This shears the GL the gas clouds that have all been contaminated by the detritus of a supernova explosion and

45:26 you get a few rotations of the galaxy. This stuff becomes very well mixed and the next generation of stars is going to have all the ingredients from that last round of supernova explosions. So it's like fertile ground for the next round. Yeah. Got it. All the way through. All right. I think that's all good questions. Wow. Yeah. Excellent. Patreon members, but this is for our general audience. General audience. We, by the way, if you join Patreon, we do special custom Q&A sessions just for you. And that's on the other side of the Patreon payw wall. Yeah. And it's worth paying because we dress up as Elizabeth and characters when we do that CQ. So, but that's what you're missing because you're too cheap to join. All right. Good for you. Oh, and we give out gold

46:11 bars to everybody. That's when I about that sword. And that sword, you say, "I got to use that sword, right?" And every Patreon member gets a puppy and a pony. And a pony. All right, we're done here. Yet another installment of Cosmic Queries with Paul Mccurio. But we'll find you your show on the road. Yeah, paul mccurio.com. Did someone say take that show on the road? And then that's what you did. I did it in New York and then the the authorities called and said, "Take it on the road." Uh, and uh, uh, Inside Out with Paul Mccuri on my podcast. Is there a movie called Inside Out? There is, but thanks for bringing that up. U, this is how you help me get people come. Oh, yeah. You just copied something, so don't go see it. Uh, yeah. Inside Out Interactions with the audience. You're very good on

46:58 your feet in that way. Yeah. My my show, Permission to Speak, is about sort of engaging the audience in their stories. It was born out of crowd work with an audience. Love crowd crowd audiences. But it's uh but people have f and your podcast uh Inside Out with Paul Mccuri which I've been on. Yes, you've been on and uh Paul McCartney and Stephen Coar and a lot of fun people. So, well, I wasn't enough to you were the only reason Paul McCartney did it is because he found out you did it. Oh, see that's that's what I expect. And uh and he knows a lot more about the theory of relativity than you do. Weird. I don't know cuz I just thought he played music. No. Yeah. So hopefully people can check all that stuff out. report. You got it. All right. This has been Star Talk Cosmic Queries Grabag Edition. Neil Degrass Tyson here

47:44 thanking Paul Mccurio. As always, I bid you to keep looking up.