Daniel and Kelly’s Extraordinary Universe - Can We Travel Faster Than Light?

Episode Date: November 15, 2018

Why can't we travel faster than light? Can we ever reach the stars? Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

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Maximize your edge by shopping at Lenovo.com during their back-to-school sale. That's Lenovo.com. December 29th, 1975, LaGuardia Airport. The holiday rush, parents hauling luggage, kids gripping their new Christmas toys. Then, everything changed. There's been a bombing at the TWA terminal.

Just a chaotic, chaotic scene. In its wake, a new kind of enemy emerged, terrorism. Listen to the new season of Law and Order Criminal Justice System On the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. My boyfriend's professor is way too friendly, and now I'm seriously suspicious. Wait a minute, Sam. Maybe her boyfriend's just looking for extra credit. Well, Dakota, luckily, it's back to school week on the OK Storytime podcast, so we'll find out soon. This person writes, my boyfriend's been hanging out with his young professor a lot.

He doesn't think it's a problem, but I don't trust her. Now he's insisting we get to know each other, but I just want or gone. Hold up. Isn't that against school policy? That seems inappropriate. Maybe find out how it ends by listening to the OK Storytime podcast and the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. Have you ever wanted to travel to a distant star or to a planet orbiting another sun? All the time.

However, I've heard that it's impossible. Yeah, the problem is that the universe is just so big, and it comes with his built-in speed limit, makes it pretty tough. So that means that we'll never build a spaceship that will get us to another star within the span of a human lifetime. That's almost true. It's almost a hard and fast rule. Turns out there's one or two exceptions to that. Immortality. Immortality. Being frozen like an ice cube. Hello, I'm Jorge.

And I'm Daniel, and this is our podcast. Daniel and Jorge explain the universe. Where we're going to take the whole universe, break it into little bits that are by its eyes, and feed them to you one at a time. Today on the program, we are going to ask the question, Will we ever be able to travel faster than the speed of light? Zoom! That's the sound it would make if we traveled faster in the speed of light right there. We're going full throttle on this episode.

Pedal to the metal, that's right. Pedal to the podcast. That's right. And I love this question because not only do people like traveling fast, but it gives us a sense for like, will we ever be able to... I feel like the subtext to the question is, will we ever travel to other stars and get to... other places in the universe, because the universe is so darn big that it's hard to get places,

right? So if we could travel fast in the speed of light, we could actually see some cool stuff. Like, what's the nearest star to us? Oh, man, I should ask Siri, but I think it's about four light years away. Okay, so even if we're able to go at the speed of light, you still have to sit in a spaceship for four years to get there. That's if you could travel at the speed of light, yeah. But there's also the question of accelerating to the speed of light. Like, if you could, if you had a spaceship, which could get up to the speed of light, it would take a long time to get going that fast because...

Oh, just to get to the speed of light. Yeah, you can't tolerate a huge amount of acceleration. You know, like fighter pilots can take like eight or nine Gs, right? That eight or nine times the acceleration you feel on Earth. But squishy people like me and you get into a jet, we can't tolerate more than a couple of Gs, you know? It'd be like being on the craziest roller coaster ride for like a year. Year is just to get to the speed of light. Just to get to the speed of light, yeah.

And if you accelerate faster, you would just get smushed against the seat. Yeah, exactly. You'd arrive as a puddle of goo. And don't forget, you have to decelerate also because you don't want to arrive someplace going to speed of light. I see. So you'd be traveling as a puddle of goo, and you would arrive as a splatter of goo on the front windshield. That's right. But, hey, if you're a puddle of goo, it doesn't really matter when you arrive, does it?

Because you're not feeling it. Or if you arrive. Or if you arrive, yeah. That's why in a lot of these awesome science fiction books I've been reading, you spend half the trip accelerating, and then you turn, the ship turns around and spends the second half of the ship decelerating, slowing down. Because, you know, if you arrive at your destination going a gazillion miles an hour, you just blow right through there at solar system. You can't even stop or, you know, get a smoothie or anything. Okay. So the question is, is there hope of us ever getting to other stars or planets out there in the universe?

Can we ever go faster than this peat of light? That's right. So we went around and we asked people on the street. Here's what they had to say. I do believe that one day we'll be able to travel faster than speed of light. Potentially, yes. I don't think so because it's in Einstein's theory, something based on nothing going fast to speed of light. So I'm saying no. Honestly, with like the way technology is going, I do think eventually we'll reach that point, yeah. Optimistic.

Okay, so the first thing I find interesting about the responses is that everyone has an opinion. That's right. Like it's like no evidence, no theoretical background. They're like, I think so. Or they're like, no, I don't think so. It's impossible. Everybody feels like technological progress is inevitable. Like you can set whatever bar you want and eventually we'll get there.

Science will figure it out. I love that optimism, that enthusiasm that like, yeah, scientists can do anything. Yeah. Well, think about all the crazy things we have been doing, right? Yeah, absolutely. you know, like downloading pictures of cats from the internet. Yeah. And soon you'll be able to, like, change your genome using your cell phone or something like that.

You want to be a ginger? There's an app for that. You want to be taller? Dial it on your phone. That would be pretty awesome. Oh, man. Swipe right for Redhead, swipe left to be taller. Well, I think we're spinning off ideas for science fiction novels here.

But I love that optimism. And, you know, frankly, I was surprised because these days a lot of people aren't really believing in science and, like, people aren't accepting global world. warming and people aren't accepting this and that and the other, but everybody seems to believe that technological advancements will just continue to be delivered on pace. And you know people, you want technological deliverance. If you want technological marvels, you got to fund science. So if you want a fancy new iPhone or to travel fast in the speed of light, you better call your congressperson and tell them to fund basic science. All right,

end rant. It's so permeated in science fiction and movies and things, right? Like without faster than light travel, most science fiction stories that involve other planets would be super boring. That's right, exactly. Because it tells us something about the scale of the universe, right? Like, the universe is really

big. Now, the speed of light is super fast. Like, let's remind people, it's three times 10 to the 8 meters per second or 186,000 miles per second. It's like blindingly fast, right? It's not like any kind of speed we're used to. It's like in one second, a ray of light can go

around the earth six times? Is that about it? Six or seven times. Yeah, in a single second. It's incredible. It's like one. That's it. It went around the world six times. That's right. It brought us postcards and trinkets, exactly. And so it's incredibly fast. But the amazing thing is that even though the

speed of light is so fast, the universe is ridiculously big. So even going at the speed of light, it takes you forever to get anywhere. Right. Thousands of years to get somewhere, even if you're traveling as a light beam. Well, so let's just ask the question, Daniel. Can we go faster? than the speed of light.

No. Boom, end of podcast right there. That's right, we're done. It's a hard no, you're saying. We cannot go faster than the speed of light. It's a hard no with a couple of asterisks and loopholes, which maybe we'll get to later. Okay, well, let's talk about first,

what kind of speed limit is it, right? Like, if you go faster than the speed of light, does the intergalactic police pull you over and say, and give you an intergalactic ticket? No, it's actually, they're snipers, so they don't even bother the ticket. They just take you out right there. They just take you out. They don't mess around.

This is the laws of physics we're talking about here, dude. Okay. So it's embedded in the laws of physics. Yeah, and the right way to say it is that you can't travel through space faster than light can travel through space. Oh, that sounds like a loophole for later. Yeah, there's some lawyerly caveats I'm setting up for later. Some intergalactic law firm was probably salivating. They're like, I found a loophole.

That's right. I'm on retainer for some Andromeda lawyers, exactly. So what does happen? Like if I'm in a spaceship and I, let's say I live forever and I have infinite energy and I just hit the accelerator on my spaceship and I just wait, pedal to the metal for as long as it takes, what's going to happen? So in this scenario, you're an infinitely rich alien with who lives forever and this is how you're going to spend your time?

Wow. Well, first of all, you don't know that I'm not an infinitely rich alien. That's true. Okay, so you're an infinitely rich alien And you're doing a podcast with me Think even more perplexing I've lived forever So, you know

I get my kicks this way All right, so you're getting down to item number 3,472 on your bucket list And this is it So yeah, like do you hit a wall? Do you know what I mean? Like at some point I can't go faster Do I crash?

Does my engine burn out at some point? What happens if I try to go faster than this speed to flight? Yeah, well people have intuition about this kind of stuff because they're used to balls and airplanes and cars and stuff, and they think that if you put in twice as much energy, you should go twice as fast.

And that is true if you're on the surface of the earth or you're going pretty slowly. Meaning, like, if you burn a certain amount of fuel, you should get, you should accelerate a certain amount. You should go faster a little bit. That's right. And if you burn the same amount of fuel again, you should go twice as fast.

Yeah, there's a linear relationship there. Doesn't matter what your speed is. If you add energy, you add speed. That's the people's intuition. But that's not true. that's not the way the universe actually works. So what happens in your scenario is you keep pouring on energy,

but the increase in your speed starts to slow down. So at first, you speed up a lot when you're burning rocket fuel, but then you just can't get faster very quickly. And you start to approach the speed of light slower and slower and slower, so that every pile of energy or bottle of fuel you burn

gives you a smaller increase in your speed. So somebody watching you do this, like from the outside of your spaceship, They're going to see you take off really fast, but at some point, they're not going to see you go faster and faster. They're just going to see you peak in velocity. Yeah, your legions of screaming fans are just going to watch. It's going to get kind of boring because you're going to get faster and faster and approach the speed of light, but never actually get there. Right.

But what's happening to me inside the spaceship, though? Do I think I'm going faster than the speed of light, or? No, no, you don't. You are aware of your speed, and you are aware of the fact that you're not going fast in the speed of light, and you're very frustrated and you're screaming at your agent to get your better ship or whatever, whatever infinitely rich Horhead

alien Jorge does. But you just never get there. But doesn't time slow down for me too? I heard that time slows down for me so that I think I'm going faster, but I'm actually time slowing down for me. Isn't that how it works?

Or am I just infinitely wrong here? Well, you on the spaceship, time always moves for you at one second per second. but other people looking at you will think the time is slowing down for you so people watching you will see if they're like watching a clock that's in your ship they'll see it slowing down

and that's one of the really bizarre things about relativity is that not only does it tell us that there's a speed limit which is hard to understand but it also tells us that time is not the same for everybody time is a local thing like how I feel time depends on where I am and how fast I'm going So it's kind of an incremental slowing down of you.

Like I was thinking like it's really cool because we think of the speed limit as like a hard stop but it really kind of affects us all the way to the speed of light, right? That's right. Like even now, if I burn twice the amount of fuel, I'm not going to go twice as fast with my car. I'm actually going to go a little bit less than twice as fast, right?

Yeah, but it's a really tiny effect until you get anywhere close to the speed of light. You can get up to like half the speed. of light without really noticing the limits of relativity. It's not to, because and then it starts to get very, very strong the closer you get to the speed of light. So unless you have a really sleepy car, you won't

notice. Yeah, but I think people are used to thinking of it as like this thing that happens in spaceships or like physics experiments, but really it's happening all around this. Like if I move my arm back and forth here in my studio, I'm being affected by relativity. Like, it's slowing me down somehow. That's right, yeah.

And the fact that you're looking at your arm means you're using light to see it. And And so relativity is everywhere. It's deeply woven into the very fabric of our understanding of physics now. It's amazing that we went so long without understanding this really basic concept that space and time are different from what we thought they were. So I guess the question then is, why should there be a speed limit? Like, why does relativity have this weird limit baked into it?

Yeah, it's a really bizarre feature. and it comes from the observation that light always travels at the speed of light no matter what you're doing or how fast you're going relative to the thing that's shooting out the light

light is always traveling at the speed of light. That's like saying Jorge is always traveling at the speed of Jorge. That's right. Jorge is always at maximal humor, right?

Horhe's jokes are always the same funny. Well, I mean, it's kind of a weird statement. It's like saying, I'm always going as fast as I'm going. That's right. So think about it like this. You're, you know, if you have a ball, you can throw it at 10 miles an hour. Cool.

Now, what if you're sitting in a car that's moving at 10 miles an hour, and then you throw the ball? Somebody on the ground is going to see the ball is going at 20 miles an hour, right? That's cool. Right. It's like the velocities add. Yeah, velocities add. They're supposed to add. You feel like they should add.

It makes sense. It's an intuitive thing for us, right? Right. What if the person in the car, instead of having a ball, has a flashlight? Uh-huh. Well, they shine their flashlight. How fast is the light going from their flashlight? At the speed of light.

Duh, right? Speed of light. Okay, but if they're in the car and they're moving at 10 miles an hour and I'm on the ground, how fast do I measure the speed of light? Well, your intuition would say a speed of light plus 10 miles an hour, right? Because they add. Right. And that's where it breaks.

You measure those photons as leaving your flashlight at the speed of light, and I'm outside the car on the ground. I still measure those photons as moving at the same speed. Whoa. So, like, if I put a rocket on a flashlight, and the flashlight is going super fast, let's say the flashlight is going at the speed of light or close to the speed of light, and then it shoots a photon or a beam of light, that light coming out of the flashlight is not going to go faster than the speed of light either.

That's right. Two people always measure light traveling at the same speed, no matter how fast they're going relative to each other, which is really weird. That's the core nugget of the counterintuitive bits of relativity, and everything follows from that. Okay. So you can ask, why does light always travel to speed of light? And let's get to that in the minute. But first, let's connect it back to what we were saying earlier.

So if light always travels at the speed of light, that's the thing that makes it impossible to go faster than light. Okay, because it's this observation that light can go faster than the speed of light, or never does, that then limits our ability to go faster than the speed of light. Is that what you're saying? Yeah, because velocity and time are connected in relativity. If you're moving really fast past the Earth, you see time on the Earth passing more slowly.

If you were moving the speed of light, you would see time on Earth as frozen. If you were moving faster than the speed of light, you would see time on Earth moving backwards, which is totally impossible and breaks causality. I mean, trains would arrive at the station before they left. It would be crazy. I have so many questions for you,

but before we dive in, let's take a short break. My boyfriend's professor is way too friendly, and now I'm seriously suspicious. Well, wait a minute, Sam, maybe her boyfriend's just looking for extra credit. Well, Dakota, it's back to school week on the OK Storytime podcast, so we'll find out soon. This person writes, my boyfriend has been hanging out with his young professor a lot. He doesn't think it's a problem, but I don't trust her. Now, he's insisting we get to know each other, but I just want her gone. Now, hold up. Isn't that against school policy? That sounds totally inappropriate.

Well, according to this person, this is her boyfriend's former professor, they're the same age. And it's even more likely that they're cheating. He insists there's nothing between them. I mean, do you believe him? Well, he's certainly trying to get this person to believe him because he now wants them both to meet. So, do we find out if this person's boyfriend

really cheated with his professor or not? To hear the explosive finale, listen to the OK Storytime podcast on the IHeart Radio app, Apple Podcasts, or wherever you get your podcast. December 29th, 1975, LaGuardia Airport. holiday rush, parents hauling luggage, kids gripping their new Christmas toys. Then, at 6.33 p.m., everything changed. There's been a bombing at the TWA terminal. Apparently, the explosion actually impelled

metal, glass. The injured were being loaded into ambulances, just a chaotic, chaotic scene. In its wake, a new kind of enemy emerged, and it was here to stay. Terrorism. Law and order criminal justice system is back. In season two, we're turning our focus to a threat that hides in plain sight. That's harder to predict and even harder to stop. Listen to the new season of Law and Order Criminal Justice System on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. Your entire identity has been found.

Your beloved brother goes missing without a trace. You discover the depths of your mother's illness, the way it has echoed and reverberated throughout your life, impacting your very legacy. Hi, I'm Danny Shapiro, and these are just a few of the profound and powerful stories I'll be mining on our 12th season of Family Secrets. With over 37 million downloads, we continue to be moved and inspired by our guests and their courageously told stories. I can't wait to share 10 powerful new episodes with you, stories of tangled up identities, concealed truths, and the way in which family secrets

almost always need to be told. I hope you'll join me and my extraordinary guests for this new season of Family Secrets. Listen to Family Secrets Season 12 on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. So we can go faster in the speed of light because light can't go faster than the speed of light. And if we were to go faster in the speed of light, things just like don't make any sense. Yeah, time would be reversed and crazy stuff like that.

And to understand that in great detail, you have to have a few moving bits in some sort of thought experiments. We actually go into that in some fun detail in our book. We have no idea. There's a whole chapter outlining that. and dotting all the logic lines from the statement that light's always traveling at the same speed

to nothing can go faster than the speed of light. So that's pretty solid. Yeah. Yeah. And so that all comes from this one observation that light travels at the same speed no matter what. And people discovered that about 120, 130 years ago. And that blew people's minds.

It didn't make any sense at all. I mean, people did this experiment. It's called the Michelson-Morley experiment. And they shot beams of light in two different directions and then measured how fast they went. and came back. And the idea is, well, the Earth is moving. And so if the Earth is moving through space,

it has some speed, right? And so we should be able to measure that speed by seeing how fast light is moving in one direction versus another direction. But no matter when they did it or how they did it, they always got the answer that light is traveling at the same speed,

which shocked everybody. It was like, this kind of result I always fantasize about. You know, the kind of physics experiment where you get the result and people say, no, that doesn't make any sense. You must have done something

wrong but instead it requires unraveling like the whole foundation of physics well i think it's weird for people because you can imagine light going faster than light that you can imagine a little photon little wave moving faster and faster and faster like why should this little photon be limited in speed like why can it just keep going faster yeah why should there be a maximum speed limit at all right yeah even for light right yeah it's totally but you're saying like that's not how the universe like the universe doesn't like things to go faster than that. Like I know there was an idea of an ether at some point in physics history, like

maybe we're swimming in some kind of goo that just doesn't let things travel very fast through it, right? Well, the idea of ether was trying to explain what light is wiggling through. I mean, light is a wave, and most waves, like sound waves or pressure waves, are waves

through something. Like sound waves are pressure waves in air, right? So people were wondering, what is light moving through? Because if light's a wave, it has to be the wiggling of something. And that's why they invented the ether. They thought, well, light must be wiggles in this invisible thing we've never seen before called the ether. And it was not a terrible idea.

It just turned out to be wrong, you know. And so that was the origin of this experiment. People thought, let's measure the velocity of the earth through the ether, and then we'll be able to tell how fast light is going relative to the ether. But it turns out it wasn't. Light is not wiggling through ether. light is an electromagnetic radiation that moves through vacuum on its own.

It's a really bizarre thing. It doesn't have to wiggle something else. Right. But it is limited in like speed. Like there's only so fast and this stuff we call space around this, there's only, there's a kind of a maximum propagation speed. Yeah.

So light is this really bizarre thing that can only move at a certain maximum speed and nothing can move faster than that. And no matter how fast you're going, you always measure light moving at the same. speed and that always boggled my mind because it makes me feel like two people can observe the same things and get different answers and both be right you know right like if you shoot a flashlight and I'm traveling at half the speed of light to try to catch up with

it it's strange to me that you'll measure those photons as going at the speed of light and I'll also measure those photons that going at the speed of light it feels like our observations disagree but we're both correct you know we can have different views of the same events and both be right that's the the craziest thing about relativity. I feel like a really great way to kind of visualize how things break down that you once told me about was this idea that if there's a ray of light going through the universe and like you were able to catch up to it.

Like you could go as fast as that beam of light and you were standing next to it going at the speed of light, it wouldn't make any sense for you to see a beam of light. standing there. Do you know what I mean? Like if I'm going down the highway and I catch up to a truck and I match its speed, to me the truck will seem like it's just standing there. But for a ray of light, like that just doesn't make any sense to see a light ray just standing there. Like that's where things would sort of break down, right? Yeah, because not only... No, no, that's totally right. Not only can you never go the speed of light because you have mass and things that have mass can approach the speed of light but never get there. But things that are

massless always go the speed of light. So not only photons, but also gravitons and other things that have no mass, always go the speed of light. And the reason is that exactly what you said, that if they weren't going the speed of light, then you could eventually catch up to them and be next to them. But what is a photon, right? If it has no mass, there's no stuff to it, there's nothing there. It's just its velocity. So if you catch up to it and it's not moving relative to you, then it doesn't really exist. Right. So it actually, makes more sense for light to always be zooming along at the speed of light relative to everybody who's measuring it at the maximum speed at the maximum speed yeah okay and I think something you said earlier is really interesting why should there be a maximum speed yeah right and I think that's really cool and it but it tells you something about our universe right we we need there to be a maximum speed so that there's causality so the things make sense so things don't happen out of order so that cause happens before effect right if you go faster than the speed speed of light, then cause and effect breaks.

Well, let's break it down. Like, I think maybe it breaks down to the question, what would happen if we had no speed limit in the universe? Like, what if things could go faster than the speed of light, what would happen? Well, you'd have to have a totally different universe because the way our universe is set up, that's pretty much baked in at the ground level. And so the universe would be totally different if there was no maximum speed. I think one thing that's fun to think about is what if the maximum speed was different, right?

What if it was like twice as much or 10 times as much or a 10th as much? Because one deep question we have is, why is the speed of light this speed and not some other speed, right? That's an interesting idea, the idea that that's just how our universe is put together. Like, that's just baked into the rules. And maybe there's another universe where the speed of light is different or there's no speed of light. Is that kind of what you're saying? Like, it's possible maybe to construct a universe without a speed limit. I'm not sure if it's possible to construct the universe with no speed limit,

but it's definitely possible to construct the universe with a different speed limit, one that's much higher or one that's much lower. I mean, as far as we know, if you're like at the control panel of the universe, this is just a parameter that you can set, and if you change the speed of light to something else, physics still works. So we don't know why the speed limit is what it is. We can't construct universes that don't have speed limits where things travel instantaneously across time,

in space. Those things don't work because they break causality. Things can arrive before they leave and stuff like that. But we can make universes where the speed of light is different. And that's fun to think about because it changes your relationship, like we were talking about earlier, with far away things. The fact that stars are really far away really tells you about how far away they are relative to the speed of light. Yeah, let's talk about that. But first, let's take a quick break. My boyfriend's professor is way too friendly, and now I'm seriously suspicious. Well, wait a minute, Sam, maybe her boyfriend's just looking for extra credit.

Well, Dakota, it's back to school week on the OK Storytime podcast, so we'll find out soon. This person writes, my boyfriend has been hanging out with his young professor a lot. He doesn't think it's a problem, but I don't trust her. Now, he's insisting we get to know each other, but I just want her gone. Now, hold up. Isn't that against school policy? That sounds totally inappropriate. According to this person, this is her boyfriend's former professor and they're the same age.

And it's even more likely that they're cheating. He insists there's nothing between them. I mean, do you believe him? Well, he's certainly trying to get this person to believe him because he now wants them both to meet. So, do we find out if this person's boyfriend really cheated with his professor or not? To hear the explosive finale, listen to the OK Storytime podcast on the IHeart Radio app, Apple Podcasts, or wherever you get your podcast. LaGuardia Airport. The holiday rush, parents hauling luggage, kids gripping their new Christmas toys.

Then, at 6.33 p.m., everything changed. There's been a bombing at the TWA terminal. Apparently, the explosion actually impelled metal, glass. The injured were being loaded into ambulances, just a chaotic, chaotic scene. In its wake, a new kind of enemy. emerged. And it was here to stay. Terrorism. Law and order criminal justice system is back. In season two, we're turning our focus to a threat that hides in plain sight. That's harder to predict and even harder to stop. Listen to the new season of Law and Order Criminal Justice System

on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. Your entire identity has been fabricated. Your beloved brother goes missing without a trace. You discover the depths of your mother's illness the way it has echoed and reverberated throughout your life, impacting your very legacy. Hi, I'm Danny Shapiro. And these are just a few of the profound and powerful stories

I'll be mining on our 12th season of Family Secrets. With over 37 million downloads, we continue to be moved and inspired by our guests and their courageously told stories. I can't wait to share 10 powerful new episodes with you, stories of tangled up identities, concealed truths, and the way in which family secrets almost always need to be told. I hope you'll join me and my extraordinary guests for this new season of Family Secrets. Listen to Family Secrets Season 12 on the IHeart Radio app, Apple Podcasts, or wherever you get your

How would breaking the speed of light break the fundamental logic of the universe? It would break the universe because it would break causality. And by that I mean that things could happen out of order. Relativity tells us that things happen differently depending on your velocity, right? And time works differently depending on your velocity. As you go faster, you can see the order of events, the time of events change. And if you go fast in the speed of light, some things flip so that the effect happens before the cause. Like, the equations just no longer make any sense.

They just no longer make sense. Like, it just breaks. And it comes from this fact that how you see time changes based on how fast you're going, which, again, is totally connected to the fact that everybody sees the speed of light, always moving at the same speed no matter what. Wow. But the basic idea is just that it's just baked into the equations that nothing can go faster than the speed of light. That's right.

Like, it's just big. If you try to go faster, it'll just break the equations by which the universe is put together. Yep. And we have tested it a zillion ways from here to Sunday, and relativity is very solid. This part of relativity is called special relativity that describes how light moves and time is affected is totally well tested, and we really believe it. Okay. And it's underpinnings of everything we've built. So if it's wrong, then we're going to throw everything away.

Now, I'm not saying that doesn't mean it's wrong, right? It could be wrong, and it could be that we discover that it's replaced by a different theory and everything is wrong. That would be, frankly, kind of awesome. I love these revolutions at physics. But so far, it seems to be pretty solid. Like maybe your kids or some kid out there right now, future physicists, might figure it out that it's a special real relativity is wrong.

Yeah, and in fact, there was a result a few years ago where people thought they had figured that out. There was this result from the opera experiment at CERN that sent neutrinos zooming through Italy, and they thought they measured some neutrinos going faster than the speed of light. And they put out this big paper, and then it turned out to be wrong. It turned out to be an operatic tragedy. That's right. It was actually quite embarrassing. One of the cables they were using to measure the timing had come loose, and there was a little bit of jiggle.

And that was the source of the whole mistake, and they had to pull it back, and the spokespeople resigned. And it was embarrassing. So, if you're going to try to disprove all of modern physics, check your cables, make sure they're right. That's right. If you're going up against Einstein, double-check the boxes. That's right. If you're going to shoot for the king, you better kill him. So I guess then the last question is, like, does that mean that we can never reach these, like, faraway planets in a decent amount of time without turning into puddles of ooze?

Like, is that mean, like, you know, like you and me will never get to step on another solar system and things like that? Or, you know, if we can't go faster in the speed of light, does that mean that interstellar travel is impossible? Right. So it's time to return to those caveats we talked about. Yeah. Traveling through space faster than the speed of light is impossible, and as far as we can tell, will never be possible. It's not like there's some technological breakthrough or waiting for. It's like just difficult or expensive or something or complicated, right?

It seems totally impossible to move through space fast in the speed of light. Now, I say through space because that's the cost. caveat. We've recently learned the last couple of decades that space is not this fixed thing that you move through. It's not like this empty backdrop. It's squishy. It's dynamical. It can do things and we can squeeze it and expand it and ripple in it. So the caveat is instead of trying to move through space faster than the speed of light, let's change the space we're moving through. So you want to go from here to Alpha Centauri? Can we squeeze that space to make the distance shorter rather than breaking the rules of physics to go through it.

So it's kind of like we're not, space is not an empty, an emptiness, right? It's like maybe we are in some kind of like a sponge or some kind of liquid as if, you know, just as an analogy. And you can't move through this sponge faster than the speed of light, but you could maybe like bend the sponge or squish the sponge to get from one side of the sponge to the other side, you could do tricks like that. Is that what you mean? That's exactly what I mean.

And that is theoretically totally possible. though experimentally very, very difficult. It's not like we've achieved this or we're like on the edge of being able to do this or whatever. But you know, the first step in a project like this is go from impossible to possible and then the rest is engineering

to go from possible to practical, right? So I leave that for the engineers. The physicist's job is to go from impossible to possible. Next week will be a feature on your Tesla, autopilot to Alpha Centauri. Anyways. Yeah, so you might be able to, wondering, well, how is it possible?

Yeah. Well, you know that space can bend, right? I mean, where the Earth goes around the sun, because sun has bent space, so the Earth moves around it because the space is bent, right? And gravitational waves show us that, like, colliding black holes can make ripples in space. So how did you actually get from here to there? You'd have to squeeze the space, which takes a huge amount of energy. So just like a gravitational wave can propagate, you could maybe, like, create a giant

wave that somehow compresses space from here to Alpha Centauri so that it's just really close. Yeah, or some sort of standing wave that's always compressing the space right in front of you so that you can move through it rapidly. Oh, yeah. Like you're surfing a gravitational wave. Exactly. Surfing a gravitational

wave, exactly. But remember, the gravitational wave caused by like colliding black holes, squeezes space by like one part in 10 to the 20. Oh, I see. So you need an even bigger source of gravitational energy than colliding black coal so that's a tall order well in the movies like star wars and star trek whenever they go into

warp speed you see kind of they always show it as this kind of like distortion of space right like the stars stretch out or like the spaceship stretches out before it disappears but maybe there's something i mean they got something right about that right like maybe that's what they were thinking they were thinking like you're actually like stretching space or you're like compressing space and that's how you're moving faster than like yeah i'm pretty sure the guy who wrote Star Trek did these calculations before they wrote those episodes and it's motivated by actual physics, yeah.

Yeah, no, everyone in Hollywood has a PhD, right? That's right. That's why they never call me to ask for physics help, right? Because they just understand it themselves, and that's why there are no physics mistakes in any Hollywood movies. I think you've totally figured it out. So that's one loophole is that you can squeeze space so that you can travel faster through it.

Are there other loopholes, or is that the main possibility for getting to Alpha Centauri? So if you're out there about to write a check for our Warp Drive company, hold on a moment because there are other options, right? And another option is wormholes, right? This is the idea that space might not be simply connected. It might not be that every piece of space is connected to the piece of space next to it.

The connection could be a little bit more complicated. It could be that, like, some piece of space is connected to a piece of space that's far, far away, right? That's what a wormhole is, this connection between pieces of space that are far away. And that requires... Like space, maybe it's not this like just homogenous thing. It could have like little loops in there, but it could be like tangled up.

Is that what you? Yeah, exactly. It requires you to think about space in a really different way. It's not just this emptiness you move through. It's more like nodes on a subway station, right? And they can be connected in any way. You can travel from one to the other.

And so... Why not, right? Yeah, why not? Exactly. In fact, we think that space probably is that way. At the tiny quantum level, space might even be quantized and discrete.

and that you can move around, like you move around a subway map. And it could be that on the macroscopic level, these things exist too. And general relativity, the theory that tells us about how space time is bent and all that stuff, does allow for wormholes. It's totally possible. Now, there's a huge number of caveats there, like, we've never seen a wormhole, so we're not sure. So they're theoretical only? They're theoretical. Okay.

Yeah. But you know what? Black holes used to be theoretical. They used to be like, well, here's a funny property of general. on relativity, but nobody's ever seen one. Gravitational ways we're theoretical, too, right? And we just detected those. Yeah, exactly.

Exactly. So maybe, you know, wormholes are last year's black holes, right? Wormholes are the new 40. Trendy. They're trending. Hashtag warmhole. Yeah, hashtag put Kanye in a wormhole. And so we think they might exist, but we've never seen one.

We have no idea how to make one. We have no idea how to keep them over. open, and maybe most importantly, we don't know what it would be like to go through them. Probably, if you went through it, it would stretch and squish you and you'd be that pile of goo anyway. Oh, but you could maybe send like a signal or a probe or maybe something... Hamster. Are you going to say hamster? Don't send a hamster hornet. I'm going to call the SPCA on you. Not my hamster. Not my hamster. Yes, you probably could send information through the wormhole and so you could talk to the

aliens. Interesting. You know, or whoever's on the other side of the wormhole, the future you or whatever. I see. Yeah. So even though you can't travel through space fast into the speed of light, and that's pretty solid, there are some ways you might be able to traverse huge distances without waiting a zillion years. So there is some hope.

You're saying theoretically it's possible. And so maybe, like our people on the street that we talk to, maybe there's some future engineer or physicists will figure out how to make it happen. That's right. And if you do, please, send us a number. note because we want to be involved. Yeah, we want to be able to spend my infinite riches out there. That's right. And I think probably that's what the folks we interviewed.

That's probably what they were expressing. They probably weren't thinking, well, I'd sign special world too. He says it's impossible, so no. They were thinking, well, humans figure it out. And whenever we're faced with a problem, somebody comes up with a solution. There's so many smart people out there with their brains cooking on this, that, and the other, that somebody will figure out a way to get there faster than light speed travel. even if you're not actually going faster

than light speed through space. So that's what I like to think that people were thinking that there were this optimistic view of science solving every problem that we have. And maybe the person who figures it out is like out there right now, you know? Could be some kid or some person out there

who... It could be somebody listening to this podcast, getting inspired right now. Scribble those ideas down. Don't forget them. Include us in the patent, please. That's right. Or we will sue you.

I have some good lawyers from Alpha Sintrari. We will see you at this beat of light. That's right. Well, thank you very much. Hope you enjoyed that. We'll see you guys next time.

As we explain the whole universe. If you still have a question after listening to all these explanations, please drop us a line. We'd love to hear from you. You can find us at Facebook, Twitter, and Instagram at Daniel and Jorge. that's one word, or email us at

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