Daniel and Jorge Explain the UniverseHint: It's not tunnels in switzerland.
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Yeah, okay, are you any good at bowling? By any chance?
I am either the world's best or worst buller, all right?
But when you go bowling, do you ever get any like gutter balls?
I can't deny that I get gutter balls.
All right? But are you so off the mark that sometimes your bowling ball ends up like in the next lane.
I also can't deny that that's ever happened to me.
Oh man, Well, in that case, you might have a special physics distinction. Oh how's that? You might be the world's first quantum bowler.
Is that another TV show like Quantum Leap, but about quantum bowling?
That's right, it's the Big Lebowski meets Quantum Leap. It's my new pitch.
Hi. I'm Orge. I'm a cartoonist and the creator of PhD Comments.
And I'm Daniel. I'm a particle physicist, a terrible bowler, and the co author of a book with Jorge called We Have No Idea About All the Mysteries of the Universe.
So welcome to our podcast, Daniel and Jorge Explain the Universe, a production of iHeartRadio.
That's Right, in which we take things around us in the universe that we find amazing or crazy, or wet and sticky, or just weird and interesting, and we try to explain them to you.
It's right. All the strikes, all the gutter balls, and all the spares out there in the universe.
That's right. Even the splits. We'll roll it right down the middle for you and into your brain.
Right.
Sometimes there's even quant a spin on the ball.
Right. I have no idea how to do spin on the ball. I see people do that. I've tried to do that. It's failed miserably. I'm all about the straight Grandma.
Roll spin actually helps you.
You think. As a particle physicist, I'd be all pro spinning balls and all that stuff, but I found it impossible. My wrist a most breaks every time I try to do it well.
On the program, we usually talk about topics that people have questions about, or people are really curious about about the universe, about physics, about how the world and how reality really works. And so today we're tackling a pretty interesting topic, right, Daniel, that's right.
This is a topic people wrote in and asked us to explain. And I think it's because they hear talked about in physics podcasts, and you read about it in physics books, and there's a bunch of online videos talking about it, but frankly, there are very few actually satisfying explanations, and I think people wanted us to dig into it and see if we could explain to them what's going on.
It's definitely one of those topics that sound cool for sure, Like just those two words put together.
Well, anything after quantum sounds cool, right, Quantum.
Banana, quantum bowling, even that sounds interesting.
An evening of quantum bowling with Daniel and Jorge. That sounds like an event you'd pay twenty bucks to go to. Right.
Well, Today, on the program, we'll be tackling a subject that is almost seems like magic maybe, and that a lot of people assume ciate with perhaps teleportation, the idea that maybe you can move from one spot to another spot kind of instantly, or through a wall or something like that, so they On the podcast, we'll be talking about quantum tunneling.
Quantum tunneling is one of my favorite topics because it's one of those really weird effects you see in quantum mechanics. You know, when you zoom in on the world and you discover it's microscopic nature. You try to understand it in terms of things we know and understand, and your brain is trying to use particles and waves and all this stuff. This is one of those effects that really just stumps us when we try to explain it in terms of macroscopic things. We try to get intuitive handle on it, and so it just shows us that the world is so different from the world that we actually understand.
I guess my question, Daniel, is am I going to spend this episode complaining about the naming of this effect, Like is this really like a tunnel?
Like every other episode.
Like every other episode of this podcast.
Probably, yes, Probably we'll spend most of the time you complaining about the name and me trying to argue that the physics version is different from the cultural version or.
Whatever, and that there's poetry in physics.
There is some poetry in physics. There's also plenty of clumsiness. Now this this is a fascinating topic because it's the kind of thing that's really impossible to explain in terms of classical analogs. You know, things that you have intuition for particles and waves and bowling balls. It's just something that those things can't do. And so it opens the door in our minds. It says the universe is weirder than you will ever understand, right, And that's the kind of thing that got me into physics, you know, the revealing that the universe operates under rules, but rules that are weird and in some ways alien to the world that we know.
So, yeah, it's got two cool words, quantum and tunneling, and so I don't know, that makes me think of like something that drills deep down into the quantum realm, or you know, something that make lets me like traveled to the quantum realm or something.
What is the what is the quantum realm? Where is it? How do you get there? That's a whole other podcast episode.
It's on the ad Men movies obviously.
All right, well, we'll have to have Paul Rudd on as a guest and Michael Douglas since he's Professor PIM, and they can explain to us all about the PIM particles in the quantum realm. But you're right, quantum tunneling does have a really cool sound to it. And so, as usual, I was wondering, like, what do people know about quantum tunneling? Do people does everybody already understand this and we don't need to explain it or is it a huge mystery? Do people have misconceptions? And so I walked around campus that you see Irvine, and it costed friendly strangers to ask them.
So before you listen, to these answers. Think about it for a second. If somebody asks you randomly on the street and didn't give you the option of googling it, would you know what quantum tunneling is?
That's right, no googling allowed.
Here's what people had to say, Uh.
Do you know what quantum tunneling is? Now? I don't know. It makes me think of like mountains in Switzerland and how they have to like build tunnels and neath them, and then that's where Sern is, So there's probably some quantum tunneling down there. I have Can you explain it? No?
I have not.
No, not really no, probably not. But I've heard I've heard of it, but I'm not sure what the concept is. I don't know. What does that mean?
No, I have not.
I do not.
I have not heard of that.
I have not.
Something has to do with light and like how electrons fall around something like that.
All right, not a popular or familiar topic. About half the people had never heard of it.
That's right. People that were pretty clueless. Though some people were pretty creative. I love the the answer about tunnels near Siren. That was very creative.
M Yeah. They said that it made them think of the tunnels underneath the mountains of Switzerland. Because Switzerland has tunnels and they do physics experiments. So therefore two and two together. Obviously, that's what a quantum tunnel is.
It's not a terrible answer, like, you know, what kind of tunnel do you need to build a large Hadron collider? You know, hey, a quantum tunnel, right, a tunnel in which you do quantum experiments. That's not a terrible answer. Maybe that's more of a quantum And the truth is, the Swiss are awesome in building tunnels, and they sort of have to be because they're surrounded by mountains, but they really are world class in building these tunneling machines. And so it's no surprise that the large Hadron collider is in Switzerland because that really is the best place to build tunnels for your quantum experiments.
Yeah, they have to dig all those tunnels to burial that money that they keep for rich people.
Oh that illicit illicitly got in gold.
You know, hey, what do you mean, I have a Swiss bank account in my dreams?
Well, you know, true story. I discovered by opening her mail that my wife has a Swiss bank account. She has a retirement plan in Switzerland.
All right, what are the secrets of you covered by opening her mail?
Oh? No, The best part of the story is that she didn't know she had a Swiss bank account until I told her.
It feels like a Born movie here.
No, it has actually a pretty mundane explanation. When we were in Switzerland so I could work on the large Hadron collider, she had a job working in research in Switzerland, and unbeknownst to her, they opened an account in her name and deposited some retirement funds there. And then we discovered it later, like, oh my gosh, look Katrina has a Swiss bank account with money.
That's how backing work in Switzerland. They just give it away.
Yeah exactly. So, yeah, she has a Swiss bank account, but I don't.
Well anyway, so people were not very familiar with quantum tunneling, which means that hey, we can we can talk about it on that podcast.
That's right, It's an awesome topic to demystify. First we'll explain what it is, and then we'll explain how it works and how it's not teleportation.
Right, that's my big question is is it like teleportation? Is it associated with teleportation. Can we teleport with quantum tunneling? All right, start us off, Daniel, how would you describe what quantum tunneling is?
So I think the best place to start is to sort of warm up our intuition, Like, let's think about this problem using things we're familiar with, and then we can make the analogy to the quantum version, and we can understand where that breaks down, like where our intuition goes wrong. So let's start with our intuition, and there's sort of the problem. The kind of problem we're trying to describe is sort of like playing with the bowling ball inside an empty swimming pool.
The just go for the bowling ball in swimming pool.
Yeah, I mean, isn't that a familiar thing when you see a swimming empty swimming pool. Don't you think, I wonder what would happen if I threw a bowling ball in there.
Well, let's give our listeners just a quick idea of what we're talking about. So quantum tunneling is kind of this idea that a particle, or in the usual case it's an electron, it can sid of be on one side of a barrier in one moment and then the next moment, it's on the other side of the barrier.
Right. The general idea of quantum tunneling is that it's really hard to keep electrons in a little trap or in a little hole, that that they really they're hard to pin down. And people are probably familiar with that because the Heisenbergen certainty principle, like, you know, you can't really isolate a quantum particle in one little spot in space very long, but you know if you try to do it, then you know eventually it's going to leak out. And the point of quantum tunneling is that electrons can build these tunnels or burrow through these barriers to to you know, adjacent little holes or adjacent little wells.
So that's the idea is that it's like you have a particle and there's a barrel in front of it, and at some point it just moves to the other side of the barrier.
Yeah, exactly. You can see it on one side of the barrier, and even if it doesn't have enough energy to get over the barrier, sometimes you see it on the other side and then you have to ask, like, how did it get here? Right? Right?
Like spontaneously, it just appears on the other side or what.
Yeah, well, sometimes on one side and then it's on the other side, and then it goes back right, And there's a lot of interesting stuff there about like, you know, if the particle was here and then later it's there, how did it get from one place from the first place to the next place. Right In your mind, you're used to things. If it's in one spot and then later it's in another spot, you imagine it took a path from one spot to the other spot, Right, That's the way classical things work, baseballs, hamsters, whatever. But that's not true for quantum objects. Quantum oogicivets are here and then later they're there, and there iss not necessarily any path between those places that the particle took.
It didn't move, It just was here and then it was there.
Yeah, it's frustrating because quantum particles don't have this underlying hidden truth.
Right.
It's not like there is a true story about where the particle was at every moment and we just don't know it. It doesn't have that story. That story doesn't exist. You know, it's in a location only when you ask where is it, and then it's in a location later when you ask where is it.
You're saying particles don't really have a here or there. It's like they're around here.
Well, they have a here, like at some moment you can say it's here, and another moment you can say it's there. But you can't connect the dots, right, You can't say that there must be a line between those two dots and the particle took that line or there. Doesn't have to necessarily be aligned. It's just here and then later it's there. It's you know, it's like frames in a movie, but without the intervening connections.
Like if you're watching a movie, you know, the person would be standing here, and then suddenly they'd be standing over there and then be studying this other part of the frame. Right, almost like there were teleporting between spots.
I was just going to say that that's not teleportation. Right, when you're watching a movie and you know, and you watch this frame by frame, you don't imagine they're teleporting from frame to frame. Right, you're just saying, well, I know he's here in this frame, I know he's there at that frame. Right, that's not teleportation.
You're saying a quantum particle doesn't have a path between these two things. It's like, if you ask it where it is, it'll just kind of pop around all over the place.
Yeah, you can ask a particle where it is and it will answer, right, and then later you can ask it where it is and it will answer. But you don't necessarily know anything about where it is in the intervening time, and you can't assume that there's some classical path. You know, if you if you ask where's my baseball and what's its velocity? Right, then you can actually predict exactly where it's going to go at any moment. And so it has this thing we call the cl classical path. It's position and velocity at any point in time, and when you're looking at it, you're just sort of sampling that. Right. But for a quantum particle that doesn't exist, you can ask where is it, and you can ask where is it later? Right, But you can't connect the dots between those two and assume that there's a path that it's following.
Well, this is a perfect point to take a break.
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Okay, so, then the idea of quantum tunneling is that a particle is on one side of a wall or a barrier, and then the next instant it's in the other side of the barrier. And so what we want to do here today is sort of explain how that happens and why it's not teleportation.
Yeah, exactly how does that happen and what does it mean and why it's not teleportation?
And so you think a great way to think get into this topic is to think about bowling balls and pools.
Yeah, well, I mean what is a barrier after all?
Right?
Like I think people think about electrons as tiny little balls. So I was thinking about, let's use a bowling ball because that's macroscopic, and what is really a barrier? Right? I mean people might be thinking like, what kind of barriers are we talking about? And so let's imagine a macroscopic barrier, like a familiar one. Right, You're the bottom of a swimming pool with a bowling ball. By the way, this is amazing video of a guy. This is what inspired me. Is this amazing video online of a guy with a bowling ball in a swimming pool and he can do these hilarious tricks where he puts like the pins behind him and he rolls the bowling ball and it does these crazy moves and knocks off all the pins. Anyway, so you're at the bottom of the swimming pool with the bowling ball, right, and what happens You just put it down.
Let's make it clear the pool is empty. I'm not drowning here, I'm.
Not empty swimming pool.
I'm not holding it onto a heavy ball. And then sitting in the bottom.
Wearing gear does not make this any more complicated. Yeah, it's an empty swimming pool with a bowling ball.
But let's also make it clear it's one of these swimming pools that has a curved floor, right, like a bowl shaped floor, right, Like if it's a swimming pool with straight edges at the bottom. This is not going to work, that's right.
Also, there's no like chainsaws or you know, traps or you know, rabbit, hamsters or anything else in the swimming pool, just you know, to be.
Clear, just just a bowling ball in an empty curved pool, you.
Know, or if it's easier for you, imagine a grape in the bottom of a bowl or whatever. But the point is what happens when you put the bowling ball at the bottom of the swimming pool. It just sits there, right, It doesn't leave. You're never going to find it in your neighbor's empty swimming pool, right, It's always going to be in that pool. And the barrier in this case is the edge of the swimming pool.
You mean, like if you don't touch it, if you don't push it, if the wind doesn't blow, it's just going to stay there.
That's right exactly. And you expect it to stay there. You don't expect to come by one day and find it in your neighbor's swimming pool. Right.
It is that if something does disturb it, like a raccoon comes by and pushes it, it's just going to roll back down to the bottom of the pool again, right, that's going to be a deal.
That's right, exactly, Because the walls of the pool are the barrier, right, that's where we talk about. It's a potential barrier. And if a raccoon comes and pushes it, you know, and he pushes it, you know, as hard as a raccoon can, then it's going to roll up, and then it's going to roll back down, and it might roll back up the other side, but it's never going to roll higher than it went originally, right, It's just going to eventually relax down to the bottom of the swimming pool. And so if you don't give it enough energy to go over the lip, then it's trapped in the pool. Right, It's never going to get out of the pool unless it has enough energy to go up and over the edge of the swimming pool, right.
And so that's the barrier, like, that's the wall.
Yeah, exactly, And your intuition says it's trapped, right, if you don't give enough energy, it's never ever, ever, ever, ever, ever, ever ever going to end up in your neighbor's swimming pool. Right, that's where your intuition says.
Right, unless there are some really strong raccoons. But that's a difference.
I don't know what kind of neighborhood this is with all these empty swimming pools and like tough gangs of raccoons pushing bowling balls. But we're sketching out quite the science fiction dystopia here.
But yeah, you don't expect it to ever be able to get out of the pool by itself.
That's right, exactly that barrier, you can consider it to be perfect. Right. The only way to the next swimming pools to go over the barrier. Right, You can never go through the barrier. These raccoons are not tough enough to throw the bowling ball like and crush the ground and get through it.
Right. Wait, what are there Swiss raccoons and they dig a tunnel?
Yeah, where they're like superhero raccoons like them. And one of the those Marvel movies is isn't there some super raccoon or does he just look like a raccoon and he's not actually a raccoon.
I never actually genetically modified raccoon.
Aliens that look like human like Earth raccoons. I never quite figure that one out. But we digress, we do, we do digress. That's the analogy right now, think instead of the bowling ball. Think of an electron and ins then when we talk about barriers, we're talking about you know, barriers to that electron. So maybe made by other particles, you know, protons or something that would repel it, right, something that would you would build to try to keep the electron localized, like a little trap.
Like a like a little magnetic field. Maybe he's keeping it trapped or something.
Yeah, yeah, a little magnetic field or electrostatic potential or something, anything you can do to trap an electron. And people do this, right, they want to study individual electrons or individual ions. They build atom traps, so pretty cool, and so people actually do this. But it's also a good case study for quantum mechanics because it helps us think about how these things work and don't work. So it's a very popular sort of junior level quantum mechanics problem in college. So what happens. You put the electron in this little well, right, and it's like a barrier. It's like a swimming pool, and you think, if the electron doesn't have enough energy to go over the edge, then it's trapped, right, just like the bowling ball. If it doesn't have enough energy, how could it ever get into the neighboring swimming pool. Well. The thing you find is that, even though it doesn't have enough energy, sometimes it appears in your neighbor's swimming pool. Like it gets through that barrier, it appears in the adjacent well. Like if you have a series of these potential wells, you know, these little traps made for electrons, and you put it in one, you come back the next day and find it in the next one. Even though it didn't have enough energy to go over that barrier.
Even though it was trapped by a magnetic field, it somehow slipped.
Out, yes, exactly, And so that's what we call quantum tunneling. Right, how did it get through the barrier? In principle, the barrier should be it should bar it, right, that's what barriers do. It should borrow it from passing, just the way the ground does, the edge of the swimming pool does. So the question is why does an electron not get stuck?
Right, Because if you try to move, the field would push it back into the trap. But somehow it's able to slip out or create a tunnel exactly exactly.
And your instinct might be to say, well, maybe like momentarily goes over the barrier, like you know, I don't know Heisenberg uncertainty blow blog. You know, maybe it borrows a little energy momentarily gets over the barrier. Right. That's tempting because you want to think of the barrier as working, and so do you want to think that if it's going to go to the other well, somehow has to go over. But it doesn't, right, it can't. It's a conservation of energy. So that explanation doesn't work. The electron doesn't get more energy momentarily magically, it's just on one side of the barrier and then it's on the next.
Like zoos didn't come down and touch the bowling ball and push it into the other swimming pool. That's impossible, that's right.
We're assuming that there's no other source of energy, right, and it never has enough energy to go over the edge of the swimming pool and into the next one. So the only way to the other swimming pool is to tunnel, is to go through the barrier.
And then once it's out and on the other side of the barrier, does it stay there or does it sometimes pop back in or does it fly off? At that point it.
Pop it pops back in yeah, it can pop back in and it can go to the next one. Right. The point, the point is that you can never really trap an electron. And the reason is not that it goes over the edge, and the reason is not really teleportation, right. The reason is that these these barriers and a quantum level are just different than the barriers we have here at the macroscopic level, and electrons are different from bowling balls. Right. We like to think of them that way because it's useful, because the way we understand the unknown is to do it in terms of the known. But in the end, these things can do things, These quantum mechanical things can do things that the classic things, the macroscopic things that we're familiar with, just can't do. And one of those things is the electron. It has a chance to just ignore the barrier. It's like every time it goes up against the barrier, a die is rolled and if it comes up you know, all sixes, it's like, haja barrier, I get to ignore you.
You said, every time it goes up against the barrier. Meaning is it like it's always pushing against the barrier or is it like a continual roll to die or what?
No that's a good point. And the way I was speaking about it was wrong because I was talking about it like having a classical path, like it has a position and a velocity at every moment. In reality, its motion is governed by this wave equation, right, the wave function that we use to describe where it is, and that tells us where it's more likely to be and where it's less likely to be. And we know that for to get from one side of the barrier to the other, it has to go through the barrier. We know this because it can be inside the barrier. Like in principle that should be impossible, right, Like how do you how can you be inside the barrier? You're not breaking the bear or the bearer is not destroyed, but it can sort of like defy the barrier. It can sort of ignore the barrier. It has a probability to just sort of like shrug off the barrier the way a teenager shrugs off a curfew. You know.
So the trap the magnetic field is trappling the electron doesn't affect the probability of where the electron can be, or it does doesn't. It doesn't it like squeeze the probability cloud of the electron or something like that.
It totally does. It affects it, but it can't trap it completely. It's just impossible to trap it completely. Unless the barrier is infinitely high. The barrier is infinitely strong, then the electron is totally trapped. But as long as the barrier is not infinite, right, imagine the swimming pool. It's infinitely deep, then the quantum mechanical builing ball can't get out. But if the if it's even if it's super high, it's a billion miles high, but not infinite, then the quantum mechanical one can get to the other side it. It just has a chance. But you're right, it does affect it. It squeezes those probabilities. The probabilities are shit to buy the barrier.
But you're saying there's still a little tiny probability that it's going to jump over.
Not jump over, but go through, right, And the probability smaller if as the barrier gets wider, and it's smaller as the barrier gets taller, So that that all makes sense. The thing that's confusing is like, how do you explain what it's doing in the barrier? Is it just like ignoring the barrier is you just have a chance to avoid the barrier. It's it's hard to come up with a sort of like an intuitive understanding of what it's doing there. You know, it's like it's in the no man's land, it's in a place where nothing should be, but there it is.
Right, is it? Because the boiling ball is not really a bowling ball, right, it's more like a cloud kind of like a like a fog. And you're saying, sometimes the fog can sort of extend and kind of appear on the other side of the swimming pool.
If you measure an electron and you say, okay, it's in my trap, and then you ask where's my electron likely to be in one second, then most likely it's to be it's going to be in the trap. There's a little bit of probability it's going to be in the barrier, and there's a little bit of probability it's going to be in the next one. Right, it's going to be in the next trap. So you know, after you know where electron is, that doesn't tell you where it is necessarily a second later. It's just you have a probability distribution of where you're going to find it, and we can candicclate those probabilities using the Shortinger equation. But that's again, that's just a description of what we have observed. Right. The shortening equation itself is not an explanation. It's just like a mathematical formulation that successfully describes what we've observed.
Oh, I see, it's the probability of where it's going to be if you measure it. So if you measure it, there's this tiny little probability you're going to measure it in your neighbor's pool.
Yes, exactly. And it's tempting to think, oh, well, that's just particles, right, particles are here and then particles are there. Right, that's not the property that allows the electron to quantum tunnel. Right. You can have that property in an infinitely deep swimming pool where electrons can't tunnel, right, an infinitely deep potential well, right, the electrons can't get out. That's the only one that can completely hold them. But in that well, electrons can still be here and then later be over there, and then later be over here as long as you're still within the well.
But if the wall is not infinitely high, then there is a probability that randomly it's going to ignore or jump over the barrier and be on the other side if you measure.
It, that's right, not jump over, but go through. Right, jumping over means.
Why not jump over? Well, jumping over means because you don't really know, right, you do know, like he was hit inside and then it was outside, and you don't know you don't really know the path it took to get outside.
Right, Well, to get over, it would need to have enough energy to go over the barrier, right, and that energy has to come from somewhere, and we have energy conservation in our universe, and so it can't go over the barrier, right. It's like the raccoon pushing the bowling ball. If it doesn't have enough energy to push it over the lip, it's just never going to go over the lip. And the reason this works we can do the calculations, and the reason it works is because the electronic is in the barrier. Like quantum barriers are just different from classical barriers. They're sort of optional. You just always have a chance to ignore them, you know. It's like speed traps. Sometimes the cop sees you and sometimes he doesn't.
But if you find it inside the barrier. Doesn't it mean it gained a whole bunch of energy.
No, it can be inside the barrier, meaning that it doesn't have enough energy to be there, but it's there. Anyway.
Where does the probability come from? You know what I mean? Like for it to be probable, he needs to have some sort of physical explanation, doesn't it.
Yeah, And the explanation is that the bowling ball analogy is wrong because this is not a bowling ball, and these are not a swimming pool. It's a weird, lobby, wavy, fuzzy thing that can do this thing that no bowling ball or swimming pool can do. And the barrier also is a little fuzzy. Right. You can't build a perfectly strong barrier unless it's infinitely high in quantum mechanics. Barriers are not the same as swimming pools, right, They're different. And so the analog breaks down, and these things can do things that the things we're familiar with can't do, and one of them is that sometimes they sort of ignore each other.
Who with that, let's take a break. We'll be back in just a short minute.
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But and the interesting thing is that it's not just electrons, right, like you're talking about all particles.
Oh yeah, electrons are just the simplest case. But any quantum mechanical particle, any particle that's motion is primarily described by like the shortening air equation. So single particles are ion or nuclei or whatever. These things can do this. Also, we see it all over the place. It's actually an important part of lots of physical processes that we know and love well.
I think it's interesting to think about the idea that, you know, these walls in the room that I'm in are sort of just barriers too, right, They're like, what's preventing my hand from going through the wall. Yeah, it's not just my inner piece, but it's like the electromagnetic forces between my hand and the wall exactly.
And that's, as you say, is a quantum mechanical barrier. Like the very tip of your finger, imagine that's an electron. When it approaches the wall, it meets a barrier. A barrier made by the electrons in the wall, and that's what's doing the repulsion. And so you're right, there's a tiny chance, so that first electron is just going to go right through the barrier instead of bouncing off.
Of it, and I might lose that one electron from my finger.
You might Or there's an even tinier chance that the next set of particles will quantum tunnel through, and an even tinier chance that also the next ones will. So there's some non zero chance that you'll put your hand through the wall without breaking the wall.
That's crazy. It's non zero chance that I can walk through, or do I walk through the wall or appear on the other side or both.
I know this would be a wor hee quantum tunneling through the wall. Yeah, there's totally a non zero chance. Now you could stand there all day, your whole life, walking into walls and not successfully go through it. And I'm pretty sure that would be your experience, because the probabilities we're talking about are ridiculously tiny. Like, for these barriers are pretty tall, and there's lots of particles and it has to happen for all of them, and so it's basically impossible, but not technically exactly zero.
So there is a possibility, Daniel, that you sitting right there where you are, will suddenly find yourself on the other side of the wall that's in front.
Of you, right exactly, there is a possibility I could quantum tunnel into the bathroom or whatever.
Let's say it happens right now. Poof, would you say you teleport it to a bathroom. What's the difference between that and actually teleporting.
Well, we did a whole episode about teleportition, remember, and we decided that teleportation is impossible while this is possible. And you know, it's really tempting to connect this, this idea of tunneling with the concept that quantum particles can sort of skip their way through life, right, They don't need to exist at every moment, sort that they're here and then they're there and the other thing. And so if you want to call this teleportation, then every particle is teleporting all the time, right. So that's my problem with it. It's like this is a natural thing that particles are always doing, even without barriers, Like even a particle in an infinite box is doing this sort of skipping thing because it doesn't exist between the moments you're observing it. So if this is teleportation, then that's teleportation also, and everything is constantly teleporting.
You're saying that you don't want to call it teleportation, not because it's not teleportation, which I would argue maybe it is experientially, but it's just that if you call it teleportation, it would sort of the dilute or break the definition of teleportation.
Yeah, if this is teleportation, then we're all teleporting all the time.
So if everyone is nice, then nobody's nice.
It's kind of what you right, it's the teleporter's quantum dilemma.
Exactly, all right, So that makes a bit more sense.
And quantum tunneling is really important, like it happens in the sun. If you want nuclear fusion to happen, the kind of thing that powers the sun, that generates all that light that you know makes you look so nice and tan and grows all that food that you eat, then you need these particles to be able to quantum tunnel through some of the potential barriers that they face. You know, particles in fusion don't like to touch each other, right, because nucleari are both positively charged because of all the protons. So to get them to fuse, you have to push them together, and they're repelling each other and that's a barrier. So you got to get them sometimes through that barrier in order to do the fusion.
Oh and you're saying sometimes they tunnel to that, but mostly do they mostly get pushed together or do they actually tunnel together.
I think it's some of both. I mean, the center of the sun is so hot, so dense that these particles can just sort of overcome the cool unbarrier, like they have enough energy. But definitely tunneling is an important part of it. Like fusion wouldn't be the fusion we know and love without quantum tunneling.
If everything's fusion, then nothing is fusion. That's what you're saying.
That's right, that's the theme today, right, label everything. And there are other effects, like you know, back to electrons. Electrons don't like to stay in little traps. But if you're building chips for computers, then you'd like your electrons to be in certain places. You want to know like hey, this transistor is on or this transistor is off or whatever. And it gets harder and harder to make transistors be reliable as they get smaller and smaller because you get dominated by these quantum effects, and these little traps get smaller and smaller, and electrons like to jump out of them, and you don't want your ones in your computer to suddenly switch into zeros. And so this actually is a big effect in minute rising transistors, or it is a big effect in speeding up your iPhone.
At some point, if you make electronics small enough, the quantum effects are going to totally mess everything up.
Yeah, exactly. Quantum mechanics messes it up again, bummer, Why can't they.
Just be electriaks out? Quantum mechanics strikes out again.
Why can't we just use little bowling balls and tiny little swimming pools instead of electrons?
Sorry, and bowling striking is good, so it wins.
Right, Yeah, strikes out exactly. You brought it full circle there, very nice.
All right. So that's pretty much quantum tunneling. It's this idea that particles are all quantum, and as such, they have these weird fuzzy location right, They're not in any particular place, and so it's impossible to trap a particle because it's fuzzy and it might slip out.
That's right, Quantum barriers are just different from the ones you're familiar with. They work under different rules, and those rules have little random exceptions to them, so sometimes they can just be ignored and it's weird and it's confusing and your intuition breaks down. But it's also wonderful because it shows you how the world works at a smaller level. Right, It reveals to you where your intuition is wrong, and that means that it's showing you the truth of the universe.
Yeah, and the truth is bowling.
Yeah, exactly. The truth is quantum bowling.
This episode brought to you by the American Bowling Association.
Yeah, exactly.
So that's what happens at the microscopic level, but on the larger level, we can't do that because you know, there's a lot of electrons in my hand, and the chance that all of them are going to quantum tunnel at the same time it's just almost zero.
Yeah, exactly. Like if there's a chance for you to roll a one million sided die and get zero, you know that probably that can happen. But if you have to do that for a million die all at once and get the same answer, then it's basically very improbable, almost impossible, so you the macroscopic stuff sort of gets averaged out, but still possible. It's still possible. Absolutely, you could quantum tunnel through the walls and not count it as teleportation. All right, It's just what quantum stuff does. Yeah, yeah, drives some physicists crazy. No, it excites us. Is it's wonderful. We're always looking for weird quantum effects that show us how the universe works. It's you know, it's it's what we what we live for, these little moments.
All right, Well, we hope you enjoyed that discussion and hope that answered all of the questions that listeners had about what is quantum tunneling.
Thanks for sending in your questions. They're inspiring. And if you have questions about things you'd like to see explain, please send them to us at questions at Danielandjorge dot com.
We love your messages, that's right, And if you are Swiss and would like to tunnel some money over to us, we are also available at feedback at Daniel Andjorge dot com.
Or just dump it right into Katrina's bank account if that's more venient. Here you go, all right, thanks for listening. 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 Feedback at Danielandhorge dot com. Thanks for listening and remember that Daniel and Jorge Explain the Universe is a production of iHeartRadio. For more podcasts from iHeartRadio, visit the iHeartRadio app, Apple Podcasts, or wherever you listen to your favorite shows. When you pop a piece of cheese into your mouth, you're probably not thinking about the environmental impact. But the people in the dairy industry are. That's why there were working hard every day to find new ways to reduce waste, conserve natural resources, and drive down greenhouse gas emissions. How is us dairy tackling greenhouse gases? Many farms use anaerobic digestors to turn the methane from manure into renewable energy that can power farms, towns, and electric cars. Visit you as dairy dot COM's Last Sustainability to learn more.
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