Our Burning Questions – Age of the Universe & More

What is the greatest scientific breakthrough? Neil deGrasse Tyson answers co-hosts Chuck Nice and Gary O’Reilly’s burning questions they have been saving all year about the age of the universe, the double slit experiment, and the nature of time. Is time even real?

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

• 0:00Neil deGrasse Tyson?

  Today on StarTalk Special Edition, I got my co-host Chuck and Gary asking me their most burning questions. And you will learn why Chuck can lose a gasket over thinking about time. And you'll also find out what Gary's deepest question is about this universe. And I have an answer for it, coming up.

• 0:27Neil deGrasse Tyson?

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

• 0:39Neil deGrasse Tyson?

  This is StarTalk. Neil deGrasse Tyson here, your personal astrophysicist. I got my co-host, Chuck Nice, Gary O'Reilly. How you guys doing?

• 0:49Chuck Nice?

  Hey Neil, what's happening?

• 0:50Neil deGrasse Tyson?

  Good. All right. This is a StarTalk Special Edition. It's just Chuck and Gary burning questions.

• 0:57Chuck Nice?

  Whoa.

• 0:58Neil deGrasse Tyson?

  This was just for you. It's a gift back to you for being such good co-hosts throughout the year, because I know you have burning questions. I think you do.

• 1:07Chuck Nice?

  Not to be, not, not, not to be confused with the kind of burning questions that I ask my doctor.

• 1:14Neil deGrasse Tyson?

  No.

• 1:16Neil deGrasse Tyson?

  You got ointment for that?

• 1:16Chuck Nice?

  Yeah, exactly.

• 1:20Neil deGrasse Tyson?

  Okay, I got some ointment to put on your burning questions. Yeah, there you go.

• 1:26Neil deGrasse Tyson?

  So guys, what, what do you have for me?

• 1:29Neil deGrasse Tyson?

  Chuck, you want to kick off?

• 1:30Chuck Nice?

  Should I? Okay, let's see. Oh, you know what? I'll start off with something a little personal. All right. Um, I always wanted to know, um, after a show a long time ago, you may or may not remember, your colleague from Princeton University, who I believe at the time was the head of the Department of Astrophysics.

• 1:55Neil deGrasse Tyson?

  Okay.

• 1:55Chuck Nice?

  A friend of yours, not just a colleague.

• 1:58Neil deGrasse Tyson?

  Because I postdoc'd at Princeton. I, I had.

• 2:00Chuck Nice?

  Yes.

• 2:00Neil deGrasse Tyson?

  And spent another many years there. So I have very good friends and colleagues there, yes.

• 2:04Chuck Nice?

  Yes. So afterwards.

• 2:07Chuck Nice?

  We were sitting around and you guys got into this discussion about the true size of the universe. And I tried to follow it, but then you went down a geek hole that was so deep.

• 2:22Neil deGrasse Tyson?

  Geek hole?

• 2:24Chuck Nice?

  That I was just like, what the hell? And I was fascinated by just why, and I didn't want, of course, I was like, just sitting there trying to soak up as much of it as I could.

• 2:35Neil deGrasse Tyson?

  Right, because that wasn't, that never posted. That was just.

• 2:38Chuck Nice?

  No, that was just the two of you. Yeah.

• 2:41Neil deGrasse Tyson?

  Going at it.

• 2:42Chuck Nice?

  And I was like, I, and I did, I didn't have my phone on set with me because I wanted to pull out my phone and just secretly record and be like, this is how they really talk when they are alone. This is what they really talk about. But anyway, you guys were disagreeing ever so slightly. It's not like you weren't saying the universe is this size and he was saying, no, it's this size. You guys were disagreeing very slightly on the size and how you get to the size.

• 3:16Neil deGrasse Tyson?

  Okay.

• 3:17Chuck Nice?

  And you started talking about, the only thing I understood was red shifting, but after that, there was some stuff, man, that you guys were getting into. So I just want to visit that.

• 3:31Neil deGrasse Tyson?

  You want a piece of that?

• 3:32Chuck Nice?

  I want a piece of that.

• 3:33Neil deGrasse Tyson?

  Okay. All right. So a couple of things. All right. If you ask any of us, what's the age of the universe? We'll come back at you with 13.8 billion years. It's up slightly from a couple of decades ago.

• 3:47Chuck Nice?

  Right.

• 3:48Neil deGrasse Tyson?

  Uh, with better measurements. If you'd asked me 20 years ago, I would have said 13.7 billion years. It's up slightly, but we have better data. All right. When I was in graduate school, we did not know the age of the universe and nor the size of the universe to within a factor of two. Okay, the universe was either 10 billion years old or 20 billion years old. Two different camps, depending on how they valued the data that was being put forth. It turns out the correct answer was in between those two numbers, as you might expect. Okay, as we narrow down the uncertainty of the measurements. It turns out there are two different measurements of the age of the universe. One of them comes from supernovae that are exploding.

• 4:33Neil deGrasse Tyson?

  What's good about supernovae is when they explode, they're brighter than the galaxy they're contained in. That's how much energy they're putting out. So you can see supernovae basically to the edge of the universe. All right, so they form a good sort of what we call standard candle. All right, supernovas have a commonality among them. You see where one explodes, how bright does it get, how quickly does it drop off in brightness? You calibrate that, you can get a distance to that supernova. Okay, and by virtue of the expansion rate of the universe, you get an age of the universe. There's another method you get by observing the cosmic microwave background. Does not use supernova. Each of those are highly precise methods, yet they do not agree

• 5:18Neil deGrasse Tyson?

  Right. with each other on the size or the age of the universe by a little bit. You can say, oh, it's just a little bit. No, the uncertainties in each of these measurements precludes the other answer from being correct. Okay? Damn. Because we've narrowed the uncertain. So, so the point, it sounds, you can have two numbers. Is it 13.75, 13.83? Well, who cares, between friends? But if those two measurements are tight, then that's a problem. It's a scientific problem and it's called tension. It's called tension in the cosmological mind. You can Google tension, cosmological tension, and it's unresolved at this point.

• 6:02Neil deGrasse Tyson?

  Last I checked, we don't, we can't resolve the difference between these two methods. So either we don't understand supernovae, or we don't understand the cosmic background, but we think we do, and therefore we're getting the wrong precision in the answer, or something else is going on that might involve both of them. Or maybe to think about the age of the universe is a question that doesn't have meaning unto itself. It's like saying, what kind of cheese is the moon made out of?

• 6:32Chuck Nice?

  Right.

• 6:33Neil deGrasse Tyson?

  You could try to answer that question.

• 6:34Chuck Nice?

  No, we know it's Swiss. See, we already know that. We already know it's Swiss.

• 6:39Speaker 02

  Yeah.

• 6:41Chuck Nice?

  That's been solved. That's scientifically solved.

• 6:43Neil deGrasse Tyson?

  That was a stupid question. Sorry. All right.

• 6:48Speaker 02

  But if the universe is constantly expanding, Neil.

• 6:50Neil deGrasse Tyson?

  Yes.

• 6:51Speaker 02

  Doesn't that make measurement irrelevant?

• 6:54Neil deGrasse Tyson?

  All right. So the measure would be in this moment, right? In the, in the current epoch.

• 6:58Speaker 02

  Hmm. Yeah.

• 6:58Neil deGrasse Tyson?

  Yes. So now, beyond that, because I'm trying to remember what that conversation that you were eavesdropping on was. That could have been part of it, but also, but also, we can say, well, how big is the universe? You might hear some people say, well, it's 13.8 billion light years to the edge. Okay. I've said that. That's a very common thing you'll hear people say. More precisely, and this is where we get into the weeds. That is how long it has taken the light to reach us emitted by objects on our horizon.

• 7:41Neil deGrasse Tyson?

  Okay. But over that time, the universe has expanded.

• 7:49Neil deGrasse Tyson?

  So you can ask a different question and say, how far away is that object today? You can't see it today because this light hasn't reached us today. It only just released this light today. Okay? How far away is it today? You go back to your equations, your models, and that object is like 46 billion light years away in that direction. And then that horizon goes in the other direction too. So the total size of the observable universe today is nearly 100 billion light years across. Right. Today.

• 8:30Neil deGrasse Tyson?

  But we don't see that. And so I'm raised in the, you only talk about what you can see camp. And so we see the galaxies on our horizon and we say they're 14.8 billion light years away. Their light was emitted from the galaxy when it was 14.8 billion, uh, 13.8 billion, um, light years away. So that's what we were hashing out when the cameras weren't rolling, that you rudely eavesdropped on.

• 8:58Chuck Nice?

  Yeah, well, I'm glad I did and I'll do it again.

• 9:03Speaker 02

  So while we're discussing the size of the universe, Neil, will the universe continually expand? Or will it get to a point and go, add enough?

• 9:11Neil deGrasse Tyson?

  Okay, yeah, so wait, let me finish something up with Chuck. You can say, well, I gave you the size of the observable universe, but how about the actual universe?

• 9:19Speaker 02

  Hmm.

• 9:21Neil deGrasse Tyson?

  We don't know.

• 9:22Speaker 02

  Right.

• 9:23Neil deGrasse Tyson?

  I don't know how far beyond our horizon the actual universe goes. Any more than if I plunk you down, you know, Nina the pinta and the Santa Maria in the middle of the Atlantic, just plunk you down there, you would not know how far the ocean goes beyond your horizon. You'd have to like sail it and continue to sail it until one day you run out of ocean. So.

• 9:49Chuck Nice?

  Yeah, but that horizon, although it appears to be moving, is actually not, whereas the universe's horizon is actually moving.

• 9:58Neil deGrasse Tyson?

  Oh, wait, so, so our horizon, yes, it is moving outward.

• 10:02Chuck Nice?

  Right.

• 10:03Neil deGrasse Tyson?

  At the speed of light.

• 10:04Speaker 02

  Hmm.

• 10:05Neil deGrasse Tyson?

  Okay, that has nothing to do with the expansion speed. It's the speed of light with which our horizon is growing. So in a billion years, our horizon will not be 13.8, let's round it to 14, our horizon will be 15 billion light years away.

• 10:20Chuck Nice?

  Right.

• 10:21Neil deGrasse Tyson?

  Okay? The light horizon. And in another billion, it'll be 16 billion. And every next billion years, it is, our horizon is washing over whole other parts of the universe that previously never reached us, whose light had previously never reached us.

• 10:38Chuck Nice?

  Right.

• 10:39Neil deGrasse Tyson?

  So here's the freaky part. You get to 15 billion years, what do you see? You're seeing the Big Bang for those galaxies because their Big Bang light is only now just reaching us. So the Big Bang signature is a continual signature that's expanding at the speed of light. Because every next genera, every next layer of galaxies, you're watching them being born, and then the next one being born, and then the next one, and then the next one. And that's because the speed of light is not infinite. If the speed of light were infinite, you'd have no knowledge of the past. And you know who one of the first people to try to measure the speed of light? Take a guess.

• 11:24Neil deGrasse Tyson?

  Um, I'm gonna say. Well, maybe people tried earlier, but, but. Uh, uh, uh, oh, whoa, Galileo. Yeah, he put two people on mountaintops with lanterns. Okay. Ah. And, and when one flashed, the other would open the shutter on one and close on the other. And I love his, the results of his experiment. Um, I, I bet you the results were George is too slow.

• 11:49Neil deGrasse Tyson?

  I don't know what the hell is wrong with George. I give him the cue, yet somehow he is missing this damn cue. No, wait, this is Italy. So what's George in Italy? Oh, uh, uh, Giovanni.

• 12:01Speaker 02

  Giovanni.

• 12:01Neil deGrasse Tyson?

  No, that's John. Giovanni. Giovanni is too slow, too damn slow.

• 12:06Speaker 02

  Giovanni's Johnny.

• 12:07Neil deGrasse Tyson?

  Yes, Giovanni is Johnny, but whatever.

• 12:11Speaker 02

  That's why George isn't ma- that's why George is getting it wrong to keep calling him Johnny.

• 12:17Neil deGrasse Tyson?

  It's a dune on the other mountain. Exactly. So, so I, I gotta remember, uh, he, he said something like, um, if it's not infinitely fast, if it's not infinite, it is remarkably fast. Wow. Cause he could not measure the speed. Couldn't measure the speed. But he was, he was, he's a scientist, so he, he doesn't have a number. It's just faster than he could measure. So he allowed it to be like infinite, but, or really fast, faster than Giovanni could open the shutters of his lantern on the opposite mountain. So, uh, the point is, if the, if light were infinitely fast, we'd see the entire universe all at once. All the time and all at once.

• 12:59Neil deGrasse Tyson?

  So the big bang is not some moment in time that happens to be captured by these galaxies and the cosmic microwave background in this moment. That will always be there. And it's not because it's the same thing that's there, there's other galaxies being born. Right. That are get, now giving you their information. And at 15 billion years, the, the cosmic microwave background that we now see, all of that became galaxies, stars and galaxies. So it's a fascinating.

• 13:34Neil deGrasse Tyson?

  A time machine that the expanding universe, the extent of the universe and the speed of light hands us, which is why we have cosmology at all.

• 13:43Chuck Nice?

  Damn.

• 13:45Neil deGrasse Tyson?

  Now, so Gary, the expansion of the universe, all data points to that's a one-way trip. When I was in graduate school, we were always considering, might we one day recolapse? If you want to recolapse, you need enough mass and gravity to sort of pull it back again. The universe is expanding at the escape velocity of the universe itself. So it will not come back ever. So get over it. Wow. Yeah.

• 14:09Speaker 02

  No, no, no, no, it's just, you know, hey, it's our burning questions and needed to put this fire out.

• 14:30Neil deGrasse Tyson?

  Gary, you had a burning, another burning question?

• 14:33Speaker 02

  Oh God, one of many.

• 14:34Neil deGrasse Tyson?

  Oh, okay.

• 14:35Speaker 02

  I'm sure Chuck's the same.

• 14:36Neil deGrasse Tyson?

  Give me one.

• 14:37Speaker 02

  All right, let's, let's focus.

• 14:38Neil deGrasse Tyson?

  I'll see if I have ointment for your burning question.

• 14:41Speaker 02

  Well, that is so kind of considerate of you, sir. Um, right.

• 14:45Neil deGrasse Tyson?

  You're gonna apply the ointment in your own damn self.

• 14:49Speaker 02

  Okay, I get it. We're just friends.

• 14:52Chuck Nice?

  That's the difference between being a doctor of astrophysics and a medical doctor.

• 14:57Speaker 02

  Yeah.

• 14:58Chuck Nice?

  The doctor of astrophysics is like, here's the ointment, now go on about your damn business.

• 15:06Neil deGrasse Tyson?

  Okay.

• 15:07Speaker 02

  So if I, if I think about us as a species and our intentions to go into deep space, okay, that's most likely going to happen at some point in the future. I'm not going to put a number next to it, but at some point in the future. But how are we going to communicate in deep space? I mean, how, how do we get through? To the point where we got reliable, real-time communication between ourselves. I mean, is it even possible, viable?

• 15:34Neil deGrasse Tyson?

  It's not Star Trek, where they have, if we had, if we had my, what's it called? Subspace. Subspace communication. Hmm. Yeah, there's something called subspace where they can communicate basically instantly. And we have no way to do that. So what I would say is, because, so for example, uh, by the way, this shows up with our rovers on Mars. Those rovers have to be at least semi-autonomous because we can't say, "Look out for the cliff." And then 20 minutes later, the signal gets there, depending on where Earth and Mars are relative to each other in our orbits, that's how long it can take the signal to get there. And then it drives off the cliff and you lost your rover.

• 16:15Neil deGrasse Tyson?

  Rover has to know what to not do without you giving an instruction to tell it to not do it. So, um, and by the way, if it did go off the cliff, you wouldn't know it for another 20 minutes, because then that's when the signal comes back to you. So it's a 40-minute round trip. When the astronauts were on the moon, the moon has like a two to three-second round trip delay. So the phone call between, the most, billed as the most expensive phone call ever conducted, between the President of the United States and the Apollo 11 crew on the moon, that had delays. So I'd, you know, so you can't have witty repartee, right?

• 16:58Neil deGrasse Tyson?

  Uh, when you're talking to people in deep space, not even on the moon. You can't say, "Uh, hey Chuck, how you doing?" And then I gotta wait one and a half seconds for it to get to you, and then one, the answer, "Okay."

• 17:14Neil deGrasse Tyson?

  And then I get that, oh, three seconds later, "Okay, he's okay." Okay, so that's, this doesn't work. And by the way, so bad that is, here's something people forgot about. So bad that is, that the delay to our communication satellites is too long to be acceptable in a phone call. Okay, before we had GPS and before we had cellphone towers, there were communication satellites, we still have them, but they're not used for talking to each other, that you park it between Europe and the United States, because they're geosynchronous, geostationary. So they're high, so high up, their orbit exactly matches the rotation rate of the Earth.

• 17:57Neil deGrasse Tyson?

  All right, 23 hours, 56 minutes turning. All right, that's the rotation rate of the Earth, once and four seconds. All right, so it does that. So now, you beam something from the United States up to that satellite, which is 23,000 miles up. Then it goes back down to Europe, which it can do because it sees both continents, because it's sitting right between us, over the Atlantic Ocean. And then, it beams back up and back. So that full round trip, it's 23,000 miles up, 23,000 miles down, 23,000 miles back up, 23,000 miles back down. That's basically 100,000 miles. The speed of light is 186,000 miles per second.

• 18:41Neil deGrasse Tyson?

  So that full round trip is basically a half a second. Now, when you have a conversation, where everything you say is delayed a half a second before the person replies, you can't, for example, interrupt them. It's like the old days when people spoke on CBs. You just give information, you say, "Over and out", and wait for them to get it, and then they'd speak back. Okay, that's called simplex communication, where it can only take signals in one direction at a time. Then you can have duplex or multiplex. But, point is, even that was too slow. Which led to, so Elon Musk has satellites that are in lower Earth orbit, lower Earth orbit,

• 19:24Neil deGrasse Tyson?

  so that the time travel up and back is just fine for you to talk on a cellphone. And so, so these are issues. So that's a long conversation to say, Gary, that these delays are important and they're a problem. You would hope that if you're far enough away, you don't need to talk to Houston. You got all the solutions you need. Okay? Or you don't have to speak to them with witty repartee. It'd be really hard for stand-up comedy. You wouldn't know people were laughing.

• 19:54Chuck Nice?

  Still used to it.

• 19:58Neil deGrasse Tyson?

  Is this mic on?

• 19:59Chuck Nice?

  I know you're out. I know you're out there. I can hear you breathing.

• 20:04Speaker 02

  But is there another means of communicating?

• 20:08Neil deGrasse Tyson?

  So, so if, if we don't travel through space until we invent wormholes with this mythical substance that has negative gravitational energy, but negative gravitational force to pry open the fabric of space and time. If we move through space through wormholes, then so could communication.

• 20:28Neil deGrasse Tyson?

  So if you go, if you're on your way to Alpha Centauri on our fastest spaceships today, it would take you 70,000 years. And you could be in a generational spaceship and make babies. They grow up and then they make babies and they grow up and you all die. And then, you know, 30, 30,000, no, what would it be? 2,000 generations from now? Then that civilization on the ship arrives. Okay. Um, that's a long time in the future. And all I'm saying is between now and then, we might invent wormholes. At which point we just step past you and wave and say, we'll see in 35,000 years as we get to Alpha Centauri system. So if we have wormholes, communication goes through it

• 21:13Neil deGrasse Tyson?

  and the communication is instant. Yes.

• 21:18Neil deGrasse Tyson?

  All right, Chuck, burning question. What else you got?

• 21:20Chuck Nice?

  Okay, so this is a very, I'm, I'm just gonna read the question, but then you gotta break down everything that's a part of it in order for everybody to know what I'm talking about.

• 21:33Neil deGrasse Tyson?

  Well, this is your day and Gary's day, so I will, I'm at your service.

• 21:36Chuck Nice?

  Okay, cool.

• 21:36Neil deGrasse Tyson?

  Okay.

• 21:37Chuck Nice?

  All right. How can a single electron passing through biphrisms or slits interfere with itself?

• 21:47Neil deGrasse Tyson?

  Nobody knows.

• 21:48Chuck Nice?

  Aw, man, come on!

• 21:50Neil deGrasse Tyson?

  Yeah, no, this is, uh, these are the, these are the mysteries of quantum physics. Like I said, and Gary, finish my sentence. The universe is under no obligation-

• 22:00Chuck Nice?

  Makes sense to you. Alright, so in that case then-

• 22:04Neil deGrasse Tyson?

  The, the point is, so, particles can behave as waves and-

• 22:07Chuck Nice?

  Right, I, I, okay, so I get the duality of light in that it's a wave and a particle.

• 22:13Neil deGrasse Tyson?

  Yes.

• 22:14Chuck Nice?

  But, so first of all, maybe we should tell people what the double slit experiment is.

• 22:19Neil deGrasse Tyson?

  Okay, so here's the thing. You're looking at electrons coming through, through, you, you have this barrier-

• 22:26Chuck Nice?

  Right.

• 22:26Neil deGrasse Tyson?

  And you put two slits adjacent to one another. You know, six inches, well, doesn't matter, to separate them, you're two slits. Then you have a screen on the other side. And you fire electrons into this, and you know, you know where the electrons are. You fire them in, and you'll get two points of intensity on the back screen. One in front of one slit, one in front of the other slit, and there's be some fade off to the left and right of that. Because some will get bent a little, okay. That's what happens if they're electrons. Now, you don't look at it, and you do the same experiment.

• 23:03Neil deGrasse Tyson?

  On the back wall, you don't see two, two, uh, peaks. You see what we, what's called an interference pattern of the variation of light and dark peaks that completely spreads across the projection surface. Because when you didn't look at it, the electron behaved as a wave. And when you did look at it, it behaved as electron.

• 23:27Neil deGrasse Tyson?

  And so, when a wave, waves can interfere. So a wave isn't just what you think it is, it's ups and downs. If you have two waves that are intersecting with- Each other, there'll be points where the crests match up, you get an extra high peak, points where the troughs match up, get an extra low peak, and these just continue. And you get all combinations of the two. And what that looks like, and what we call it in physics, is an interference pattern. And that's evidence that for that variant of the experiment, the electrons were behaving as waves. Now, what does, what does looking at it have to do with it? Because if you're looking at it, you gotta shine light on it. Right.

• 24:09Neil deGrasse Tyson?

  If you shine light on it, because otherwise, it's just, it's an experiment in the dark, you have no idea what's happening at all. The moment you shine light on it, the light interferes with the electrons being waves, and they become particles at that point. And so, it's called the observer effect, and the new age circles wanna believe that it's your consciousness that's affecting it. And that's one of the biggest misconceptions. Yeah, that's ridiculous. Right.

• 24:38Speaker 02

  Who was the first discovered this with waves back in the day, way back?

• 24:43Neil deGrasse Tyson?

  Uh, well, we knew, we knew about the wave interference, okay? Because you were always shining light on your electrons, but electrons had to be discovered, all right? The electrons were not known in antiquity. They had to be discovered, and then you gotta know how to manipulate them, and then you do these experiments. This is all, we are in the centennial decade of the birth of quantum physics. The 1920s was a seminal set of years. Wow. Where quantum physics was discovered, Hubble discovered that we're not the only galaxy in the universe, and he discovered that the universe was expanding. So, a lot went on in that decade.

• 25:23Neil deGrasse Tyson?

  Easy. So Chuck, we, we don't know, it just is. It just is. It is a correct description of nature. And an important philosophical point, just because we don't know how something works. Right. Why something works, doesn't mean we can't describe how it works.

• 25:42Neil deGrasse Tyson?

  Okay, you can know things and predict things, even if you don't fully understand what's happening. And that's where we are with quantum physics. We don't, it defies our common sense, but so does practically everything else about quantum physics. We are, we don't live in the quantum.

• 25:57Chuck Nice?

  Right.

• 25:57Neil deGrasse Tyson?

  There's a book called, oh, what's the guy's name?

• 26:00Chuck Nice?

  Oh.

• 26:00Neil deGrasse Tyson?

  George Gamow, physicist, wrote a book called Mr. Tompkins in Wonderland. And it's a series. And one of the stories is, the physical constants are different in his world. So as he's driving down the street, he starts seeing relativistic things happen. And all Einstein's relativity shows up in his rearview mirror, in his frontview mirror. Very clever educational tooling there. So one of them, it's quantum physics. So Planck's constant, which measures the things in the quantum, is some much larger value. Which means when you walk through a doorway, you end up diffracting, just the way particles would.

• 26:44Neil deGrasse Tyson?

  I mean, it's freaky stuff. It's called Mr. Tompkins in Wonderland. It's a whole series. Very clever, and he illustrated, it has fun little cartoons in it, too.

• 26:52Chuck Nice?

  I learned everything I know about the quantum from Ant-Man Quantumania.

• 26:56Neil deGrasse Tyson?

  Oh, yeah.

• 26:59Neil deGrasse Tyson?

  Okay.

• 27:02Neil deGrasse Tyson?

  The Marvel Universe.

• 27:03Chuck Nice?

  Yeah, which is why I know nothing about the quantum, because it was.

• 27:08Neil deGrasse Tyson?

  All right.

• 27:23Chuck Nice?

  All right, okay, here's one, Neil.

• 27:27Chuck Nice?

  So this is something that we have talked about in the past several times. And the fact that it is real is just very difficult to wrap my head around.

• 27:39Neil deGrasse Tyson?

  Okay.

• 27:40Chuck Nice?

  Okay. And that is, we have kinematic time dilation. We have gravitational time dilation. And these are not perceptions. Because you told me about the atomic clock experiment. And so the atomic clocks.

• 28:03Chuck Nice?

  Are the most precise chronological measurement of time. And we end up with different readings in these experiments. I'm, is time real? Is it a, is it a thing? Is it, is it even a thing?

• 28:17Speaker 02

  Is it a thing?

• 28:18Chuck Nice?

  Is it even a thing?

• 28:19Speaker 02

  Is it a thing?

• 28:20Chuck Nice?

  I mean, come on. Because.

• 28:22Neil deGrasse Tyson?

  Chuck is blowing a gasket.

• 28:23Chuck Nice?

  I'm serious.

• 28:24Neil deGrasse Tyson?

  Chuck just blew a gasket. Okay.

• 28:27Speaker 02

  Are humans, are humans the only species that kind of measure time?

• 28:31Neil deGrasse Tyson?

  No, no, no.

• 28:32Speaker 02

  Or quantify it?

• 28:33Neil deGrasse Tyson?

  So for example, you've heard of half-life, right?

• 28:35Chuck Nice?

  Of course, yes.

• 28:36Neil deGrasse Tyson?

  Half-life, okay. At half-life limit, let's make sure we're on the same page. There's certain elements that are radioactive, which means they decay into different elements. You start with a, with a blob of one element. And if it has a half-life of a week, let's say. That means in a week, on average, half of those atoms will have turned into a different kind of atom.

• 28:59Chuck Nice?

  Right.

• 29:00Neil deGrasse Tyson?

  It would have decayed. And then in another week, half of what remains turns into it. Okay, it's half of a half of a half of a half.

• 29:08Chuck Nice?

  Of a half of a half.

• 29:09Neil deGrasse Tyson?

  And it drops rapidly. It's two to the N power, right? So it drops rapidly. Okay. So if you have 10 half-lives, then you have 1 one-thousandth of what was there before left over. Because 10 is two, it's one-half times, one-half times, one-half times, one-half times, one-half. And you get 1,024, I think. Right.

• 29:34Chuck Nice?

  Okay.

• 29:34Neil deGrasse Tyson?

  So it's basically 1,000th of what was there. All right. You can take an element that has a half-life. And accelerate it to near the speed of light. And its decay will be delayed by the exact amount that you calculated in Einstein's relativity. And it's not carrying a Timex with it.

• 30:01Chuck Nice?

  Right.

• 30:01Neil deGrasse Tyson?

  Okay? Or Rolex. It's, whatever internal clock tells atoms to decay.

• 30:10Neil deGrasse Tyson?

  That is adjusted, that is affected by relativity. So time is real, relativity is real. Now, one way to think of it where which Jan Levin has tried mightily to get us to understand. All right, if you have two axes, okay? And one axis is distance and the other is time. Okay. Mm hmm. Oh, not distance, it's just space. One is space, the other is time. And they're like right angles to each other. All right. So it's two axes. Now, if you're sitting there going nowhere, you are not moving on the space axis. But you are moving in the time axis, aren't you? Yes. Time is going forward for you. Right.

• 30:56Neil deGrasse Tyson?

  Cause your lazy ass is on the couch and you're not actually moving anywhere. Okay. Okay. So if you start moving, then the line on this graph that applies to you is not the one that's going straight up the time axis. Because now you are moving from your previous location and now you're in a new location and you're continuing to move. So now as time progressives, you advance a little bit in the space direction. So you have a line that's at an angle right now from the vertical. Can we picture this in our heads? Of course, yeah, okay. You got it, okay, okay, great, great.

• 31:35Neil deGrasse Tyson?

  So now, so now, I, I, so Chuck, you, you've been slow lately. Gary's a former ex pro, pro football. He's gonna run while he watch you walk eating potato chips. Okay? He will run, you are both moving forward in time, yes. But he's moving farther in distance than you.

• 32:01Neil deGrasse Tyson?

  In the same amount of time, so his line will be at an even greater angle than yours will. Okay? We got this?

• 32:10Chuck Nice?

  So far. Yeah.

• 32:12Neil deGrasse Tyson?

  Okay, now, everybody's got to measure the speed of light to be the same.

• 32:18Neil deGrasse Tyson?

  This is one of the great insights that Albert Einstein had in his relativity.

• 32:23Neil deGrasse Tyson?

  Okay? In order for both of you to measure the speed of light to be the same thing, your time coordinates.

• 32:32Chuck Nice?

  Have to change.

• 32:33Neil deGrasse Tyson?

  Have to change.

• 32:34Chuck Nice?

  His would have to slow down in order, if, if speed of light is a constant, his time, which is, that, because the speed of light's got to remain the same.

• 32:46Neil deGrasse Tyson?

  Correct.

• 32:47Chuck Nice?

  So that means his time would literally have to slow down in order for him to observe me eating the potato. At the same time, Jesus Christ. See, this is what I'm talking about. What, what, what, what? What? We're both seeing the time. The time slows for him, but it's the same for me because the speed of light is, time is bullshit, man.

• 33:21Chuck Nice?

  It literally slows down for him, literally. It is not like it's a perception. The time itself slows for him.

• 33:32Neil deGrasse Tyson?

  His metabolism, his thoughts, his, any radioactive material he's carrying in his pocket, his clock, everything, the vibrations of the atoms, everything.

• 33:44Chuck Nice?

  And referentially, for me, everything is exactly the same for me. My time is staying the same for me, okay? But for him to observe me, his time actually has to slow down in order for that observation to take.

• 34:03Neil deGrasse Tyson?

  No, no, no, so let me, to be more clear. You're watching him, and from where you are, you both want to measure the speed of light to be the same.

• 34:11Chuck Nice?

  Exactly.

• 34:12Neil deGrasse Tyson?

  But the only way that can happen is if you see him move slower.

• 34:16Chuck Nice?

  Right, he's got to move slower because his time, and it's not like. It's not like I'm perceiving him to move slower. His time literally has to slow so that he can be

• 34:30Neil deGrasse Tyson?

  Make the same measurement.

• 34:31Chuck Nice?

  Make the same measurement that I.

• 34:33Neil deGrasse Tyson?

  Correct. Okay, now, now, now, if you go at the speed of light, time stops. So that would be what's so that's so that would be a line moving along the distance axis. But not advancing along the time axis. It would just be flat line there. And so therefore, a beam of light can get between any two places with zero elapsed time. So a light, a photon particle of light emitted in the center of the galaxy, which was the object of my affection for my PhD thesis, the galactic center. Those photons, I will see them travel for 30,000 years.

• 35:18Neil deGrasse Tyson?

  But if you're that photon, you don't live for any time at all.

• 35:21Chuck Nice?

  No time.

• 35:22Neil deGrasse Tyson?

  That's right.

• 35:22Chuck Nice?

  There's no time that has passed.

• 35:24Neil deGrasse Tyson?

  In the same instant, you are emitted.

• 35:25Chuck Nice?

  Right.

• 35:26Neil deGrasse Tyson?

  Correct.

• 35:26Chuck Nice?

  Okay.

• 35:27Neil deGrasse Tyson?

  We're too good to get truck off the ledge there.

• 35:29Chuck Nice?

  It's crazy. This is, I mean, and seriously, it's, it's, it's so funny because it's, it's all, it's, okay, forget it.

• 35:40Chuck Nice?

  It is mind blowing that, you know, that these are, for the measurements themselves, these are true measurements. You would think that these would be perceptions because you're talking about it being relative to an observer. But they're not perceptions.

• 35:55Neil deGrasse Tyson?

  Yeah, in fact, observer is, is an unfortunate word that we still use today.

• 35:59Chuck Nice?

  Yeah, we still use the word.

• 36:00Neil deGrasse Tyson?

  We refer to observer and a phenomenon.

• 36:02Chuck Nice?

  Right.

• 36:02Neil deGrasse Tyson?

  And people then think it's something, it's something to do with you for being human.

• 36:05Chuck Nice?

  Exactly. Right, and it really isn't. These are actual measurements. And the measurements themselves are true and correct.

• 36:15Chuck Nice?

  As they relate to the time and the constant being the speed of light. That's insane, man.

• 36:24Neil deGrasse Tyson?

  Yeah, it's crazy.

• 36:24Chuck Nice?

  It's just crazy. It's crazy.

• 36:26Neil deGrasse Tyson?

  Yeah. And, and another example, we've given it before, but now you, we have our own private burning question session here. That, um, th- this phenomenon occurs in the strength of a gravitational field as well.

• 36:40Chuck Nice?

  Right.

• 36:40Neil deGrasse Tyson?

  So the stronger is the gravitational field, the slower your time moves. So GPS satellites fly in MEO, right? We have LEO, MEO and, and GEO, right? So MEO, Middle Earth orbit.

• 36:51Chuck Nice?

  Right.

• 36:51Neil deGrasse Tyson?

  And so those are like 12,000 miles up. And so that's high. Okay? That's farther away than the diameter of the earth is up above the earth. So they're far enough away from earth's center that the difference in timekeeping for them is different than it is for us.

• 37:12Chuck Nice?

  Right.

• 37:13Neil deGrasse Tyson?

  Okay? So their ti- their clocks, since they're farther away from, are moving faster relative to us.

• 37:20Chuck Nice?

  Right.

• 37:20Neil deGrasse Tyson?

  So when they keep track of time and send us the time, we have to correct it. Because all we care about the time in our reference frame, which is earth's surface.

• 37:32Chuck Nice?

  Hmm.

• 37:32Neil deGrasse Tyson?

  Okay?

• 37:33Chuck Nice?

  So who calibrates this? What calculation are they?

• 37:36Neil deGrasse Tyson?

  We got people.

• 37:36Chuck Nice?

  Because we're constant, we got people.

• 37:38Neil deGrasse Tyson?

  We, we got people. That's why there's a National Bureau of Standards. I mean, there, there are people who think, wait, you gotta be glad they're there and they're the unsung heroes. You don't even know they're there and they're figuring this out for you. So, and, and let me tell you how, how deep it goes.

• 37:54Chuck Nice?

  They all use the Timex.

• 37:57Neil deGrasse Tyson?

  Okay. So what? How deep it goes? So, um, we're on earth's surface and we think of it as just one surface.

• 38:05Chuck Nice?

  Right.

• 38:06Neil deGrasse Tyson?

  But there's something called the geode. And the geode is the grid that the GPS satellite is actually talking to.

• 38:18Neil deGrasse Tyson?

  Now, in that grid, is the geode you're using for Earth a perfect sphere? Okay, that's a model of Earth's surface, but that's not Earth's surface. The equator is farther away from Earth's center than people not on the equator, which affects which timeframe you are in relative to the GPS satellites. So, if you want to be really, really, really, really precise, you have to know where you are on the geode, relative between the perfectly spherically modeled Earth and the Earth that has, that's slightly wider at the equator than at the poles. And by the way, we're not only an oblate spheroid, slightly wider at the equator than at the poles,

• 39:02Neil deGrasse Tyson?

  we are slightly wider below the equator than at the equator.

• 39:07Neil deGrasse Tyson?

  So we're a pear-shaped oblate spheroid. And that's harder to model mathematically. So tip, and usually you don't care about that level of precision. So, so typically, they just use a spherical approximation for Earth's surface and let the dust fall where it may.

• 39:27Neil deGrasse Tyson?

  But you might, you might arrive at a place and if you...

• 39:31Chuck Nice?

  I mean, are we talking, are we talking nanoseconds here or?

• 39:35Neil deGrasse Tyson?

  No, we're talking about you're one doorway away from where you were, had intended to be, that sort of thing. But you're usually tracking down an address. And so, once you see the address, you're not still using GPS to decide that. You know who needs these coordinates? The military. Because if they're sending a missile via GPS guidance.

• 39:54Chuck Nice?

  Yeah, that doorway, that doorway can make a difference.

• 39:57Neil deGrasse Tyson?

  Yes, the doorway to the left or the right makes a difference.

• 40:00Chuck Nice?

  Right.

• 40:01Neil deGrasse Tyson?

  So, yeah, they have to know what the exact shape of the Earth is at the point where they're interacting. And of course, GPS was invented by the military, by the US Air Force, now under the control of the US... Postal Service.

• 40:22Neil deGrasse Tyson?

  Chuck, let's try.

• 40:23Chuck Nice?

  They don't, they don't want to get the wrong mailbox.

• 40:27Neil deGrasse Tyson?

  We'll excuse him on this one. The GPS was designed and built by the military. And it is, it is controlled by, was controlled by the US Air Force until

• 40:41Neil deGrasse Tyson?

  it is now under the control of

• 40:44Neil deGrasse Tyson?

  the US Space Force.

• 40:47Chuck Nice?

  Oh, I, you know why? I have never accepted Space Force.

• 40:54Chuck Nice?

  That's why I was wondering, I was like, why am I not getting this?

• 40:57Neil deGrasse Tyson?

  And Chuck, I cannot begin to tell you how irrelevant that fact is.

• 41:01Chuck Nice?

  I know.

• 41:01Neil deGrasse Tyson?

  To the world.

• 41:02Chuck Nice?

  I know, and I need to.

• 41:03Neil deGrasse Tyson?

  That you don't accept it.

• 41:04Chuck Nice?

  And I need to get over it because guess what? And you, and, and I just felt, first of all, I thought it was a dumb ass name and.

• 41:13Neil deGrasse Tyson?

  What, what? It's space and it's a war. Wait, dude, dude.

• 41:16Chuck Nice?

  Because, listen, we already. No, dude, shut up. We already have the Air Force and then you just go, oh. Okay, and now we're gonna make it Space Force.

• 41:26Neil deGrasse Tyson?

  Okay, hold, hold on, okay. So, we still have the Air Force.

• 41:30Chuck Nice?

  Yes.

• 41:30Neil deGrasse Tyson?

  They were, they worry about the air, okay? Space Force worries about stuff that is not moving through the air, okay?

• 41:40Chuck Nice?

  Right.

• 41:41Neil deGrasse Tyson?

  Those are called satellites and other rockets, all right? Did you complain in 1947 when the Air Force split from the US Army?

• 41:52Chuck Nice?

  Well, no, I didn't.

• 41:54Neil deGrasse Tyson?

  No, yeah, because you weren't born, but had you been around, would you be, would you be imitating? Who was president in 1947? Uh, who was it? Uh, Truman? Would, would you be imitating Truman and say, and saying, well, why have an, an, an Air Force? When we have the Army who can fully take care of the Air Force?

• 42:13Chuck Nice?

  Air Force sounds cool.

• 42:14Neil deGrasse Tyson?

  Army has soldiers on the ground with tanks.

• 42:16Chuck Nice?

  Sounds cool, it sounds cool. Truman had it right. It sounds cool, so you know that. Where Space Force sounds like something that, um.

• 42:25Neil deGrasse Tyson?

  Science fictiony.

• 42:26Chuck Nice?

  That Seth, no, that Seth, um, McFarlane came up with. That's what Space Force sounds like. Sounds like, they were like, Seth, we need a, we need a name. We need a name for an organization that's going, uh, put us out in space and take care of all of our space related. How about Space Force? Let's go with Space Force. Like, nah, nah, nah.

• 42:46Speaker 02

  But anyway.

• 42:47Neil deGrasse Tyson?

  So the entire space branch of the Air Force basically pulled away to become the Space Force. Where command and control is different, all the, the, uh, there's so much that it's, it's maybe not entirely as different from these Air Force as Air Force was from the Army.

• 43:03Speaker 02

  Right.

• 43:04Neil deGrasse Tyson?

  But it's different enough to justify its own branch. And now they have a seat at the table in the Joint Chiefs of Staff. Gary, we got time for only one more burning question, but it has to be, can't just be any question. It has to be burning.

• 43:17Speaker 02

  Okay.

• 43:18Neil deGrasse Tyson?

  It's our own, it's our own burning man.

• 43:21Speaker 02

  All right, here we go. What is the one scientific breakthrough for you that has shaped the world the most? And maybe what is the next one for you?

• 43:31Neil deGrasse Tyson?

  That has shaped the current world?

• 43:33Speaker 02

  Yeah.

• 43:34Neil deGrasse Tyson?

  The fact that matter

• 43:41Neil deGrasse Tyson?

  is made of atoms? And atoms are made of particles.

• 43:48Speaker 02

  Really?

• 43:49Neil deGrasse Tyson?

  The, I don't think anything has shaped the world more than that knowledge and awareness.

• 43:55Speaker 02

  That's a, that's a really cool answer.

• 43:58Neil deGrasse Tyson?

  Because that's what gives us electricity.

• 44:00Speaker 02

  Yep.

• 44:01Neil deGrasse Tyson?

  It gives us the nuclear power.

• 44:04Speaker 02

  All of our communications.

• 44:05Neil deGrasse Tyson?

  It gives us our understanding of molecules.

• 44:09Speaker 02

  Yep.

• 44:10Neil deGrasse Tyson?

  How and why they work. It gives us our understanding of the periodic table of elements. Why is it periodic? Okay. All of that comes from that fundamental realization. Because think of it before then, it's like, oh, I'm a wood cutter. I just care that my wood atoms, you say it's atoms, okay, I got wood atoms, fine. I don't care, I'm just gonna cut, okay? Oh, but wait a minute, when you burn wood, what happens?

• 44:37Speaker 02

  Oh.

• 44:37Neil deGrasse Tyson?

  Oh, there are molecules there that have energy that break apart, but, okay? So, th- there it is.

• 44:45Speaker 02

  Yeah, that's a, that's a really cool answer. I would have never thought of it that way, but yeah, yeah, that, that discovery changes everything.

• 44:54Neil deGrasse Tyson?

  And, and if I can tell you one other thing, there's some professors at MIT who created a course called Energy, and big fat textbook. Everything you ever wanted to know about energy.

• 45:09Neil deGrasse Tyson?

  Machines, the conversion of energy from one thing to another. This goes on and on and on.

• 45:14Chuck Nice?

  How I can get more of it in the afternoon? Cause I gotta, I feel so bad around two o'clock.

• 45:18Neil deGrasse Tyson?

  You know, I don't know if they get the caffeine.

• 45:20Chuck Nice?

  Oh, they don't get to that? Okay.

• 45:22Neil deGrasse Tyson?

  Wait, so let me get the book. Hold on a sec. Here's the book.

• 45:26Neil deGrasse Tyson?

  The Physics of Energy. Okay.

• 45:29Chuck Nice?

  All right.

• 45:30Neil deGrasse Tyson?

  Robert Jaffe and Washington Taylor. Okay, two professors. And look how fat the book is. And so I want to read to you my. Um, I, I wrote a blurb for it. Okay. Here's my blurb. Is that a technical term? Yeah, it's a total technical term. Here it is. You ready? All right. And I pride myself on always having the shortest blurb. But this one is about the same length as the others. Okay, so here it goes. Ready?

• 46:01Neil deGrasse Tyson?

  If your task was to jumpstart civilization, but had access to only one book, then the physics of energy would be your choice. Professors Taylor and Jaffe have written a comprehensive, thorough and relevant treatise. It's an energizing read as a standalone book, but it should also be a course offered at every college, lest we mismanage our collective role as shepherds of our energy hungry, energy dependent civilization.

• 46:35Chuck Nice?

  Wow.

• 46:36Neil deGrasse Tyson?

  Well. And then they inscribed it to me. A little inscription there. I'll read that to you. Dear Neil, here's hoping we don't have to jumpstart civilization anytime soon. Yeah. So I would say a close second to knowledge that there are particles is the fact that we have learned to understand, measure, harness and transform energy from one form to another. That in fact is the backbone of modern civilization.

• 47:09Chuck Nice?

  Very cool.

• 47:10Neil deGrasse Tyson?

  All right.

• 47:11Chuck Nice?

  Good answers, man.

• 47:12Neil deGrasse Tyson?

  My, my question got a great answer. Oh, no. Or was it just a great question? And I gave an average answer.

• 47:20Neil deGrasse Tyson?

  Take credit, Gary. Take away your credit. I'm taking and running. I'm running. All right. Well, I enjoyed this. My co-host giving them a chance to ask burning questions. We might make this a regular thing. I don't know. But you have to earn it. All right, Gary. All right, Chuck. This has been StarTalk. Neil deGrasse Tyson here with burning questions from Chuck and Gary. As always, I bid you to keep looking up.