Daniel and Kelly’s Extraordinary Universe - How small is an electron?

Episode Date: March 19, 2020

Shrink down the the quantum realm with Daniel and Jorge and discover the size of the electron Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for p...rivacy information.

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Starting point is 00:00:00 This is an I-Heart podcast. 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
Starting point is 00:00:33 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.
Starting point is 00:01:01 Now, 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. I'm Dr. Scott Barry Kaufman, host of the Psychology Podcast. Here's a clip from an upcoming conversation about how to be a better you. When you think about emotion regulation, you're not going to choose an adaptive strategy,
Starting point is 00:01:26 which is more effortful to use. unless you think there's a good outcome. Avoidance is easier. Ignoring is easier. Denials is easier. Complex problem solving. Takes effort. Listen to the psychology podcast on the iHeartRadio app, Apple Podcasts, or wherever you get your podcasts.
Starting point is 00:01:52 Hey, Jorge, you're a visual artist. So I have a question for you about how you visualize things. Well, first of all, thank you for calling me an artist. Cartoonists don't usually get that kind of respect. But do you mean that can I draw my answer? Yeah, maybe when we upgrade this podcast to a YouTube channel. But until then, here's my question. What is the biggest distance that you can visualize,
Starting point is 00:02:17 that you can sort of see in your mind? Well, I think anything bigger than the distance between my bed and the fridge feels like an infinity. I guess maybe like the biggest distance that I can wrap my head around would be maybe like the size of the solar system, you know? Like I think I have a intuitive sense of that, but maybe anything bigger just kind of blows my mind. All right, so then turn it around. What is the smallest distance that you can visualize? Probably the width of a thinly sliced banana.
Starting point is 00:02:50 Feels like maybe you should have had a snack before we did today's podcast. I am Jorge. I'm a cartoonist and the creator of PhD comics. Hi, I'm Daniel. I'm a particle physicist, and I don't eat bananas no matter how thin you slice them. Really, you're anti-banana. Like, you avoid them? I'm anti-bananite, yes. The minute here on the air. I didn't know that. Oh, my God.
Starting point is 00:03:29 How do we even get along all these years? I don't know if I can continue doing this with you anymore. So if you get them in a salad, you pick them out or something? How far does your... Who puts banana in a salad? What are you talking about? You were offending salads. How far this is anti-binaninus goes, Daniel?
Starting point is 00:03:48 Well, let's see. If I was dying of starvation next to a banana tree, I would eat some bananas. I'll put it that way. I see. Oh, man, you don't know what you're missing. But for those of you who are not anti-banana, welcome to this podcast. Daniel and Jorge Explain the Universe, a production of I-Hard Radio. And banana lovers and banana haters are all welcome on this podcast because we... No, no, no, no, only the lovers.
Starting point is 00:04:16 Because we all share the love of the universe and the mysteries and the incredible cosmic questions, like how can anybody stand to eat a banana? No, like, how big is our universe and does it all make sense? Should I remind you, Daniel, that bananas are part of the universe? If you love the universe, technically you love bananas. But welcome to our podcast in which we do try to explore everything around us, including bananas and other delicious or non-dilicious items, and explain how it all works to you.
Starting point is 00:04:45 Yeah, we try to think about the bigness of the universe, the limits of space and planets and stars, but we also like to talk about the small things in life and in the universe, And sometimes it really stretches your mind, right? To sort of in one conversation, think about how big the universe is and also how small things are. Yeah, and we try to take you on a tour of the sort of current thinking of scientists. How do scientists think about this stuff? How do they fit the whole universe in their brains?
Starting point is 00:05:14 Or what do they visualize when they think about the inside of a black hole? Or how do scientists think about the very, very tiny? What does a particle look like inside the mind of a particle? physicist. Yeah, because, you know, we know that the universe is made out of tiny little particles, and we like to say tiny little particles, but I guess you don't often think about what tiny really means. Yeah, we do this a lot when we think about the quantum realm. We try to sort of use the ideas we have from our everyday experience and apply them to particles. So apply them to these tiny little bits so that we can make sense of them. Because, you know, you can't see these
Starting point is 00:05:50 things directly. So you have to sort of build a mental picture. And we try to talk about how how they have mass and charge, and we even give them, you know, flavor and spin and other sorts of things that we're familiar with from our world. But you have to wonder, like, how well does that really work? Is it really relevant?
Starting point is 00:06:07 Or is the quantum realm just totally alien and we will never really get our minds around it? Yeah, I thought we had already decided that everything looks like Lego pieces down at the fundamental level. They don't look like the blocks with circles that say Lego on them? Well, it's easy to do a test.
Starting point is 00:06:24 You know, if you step on them and they cause you great pain, then they definitely are the shape of Lego pieces. I think they make round Legos too now, damn. Finally, to save parents. But, you know, this is all we can do as humans is we can take the ideas we are familiar with and we can try to map them down to the quantum realm to think about this. Yeah, and sometimes that intuition kind of fails, right? Or it breaks down when you get down to that quantum realm, that quantum level, right?
Starting point is 00:06:50 our ideas of what something is or how solid something is or what shape it has. It all sort of breaks down into kind of mathematical gooply-goop, right, down at the quantum space. I think it has a little bit more substance than mathematical goop-de-gloup. Oh, really? It's a bit more poetic. That's not a technical term? No, it's a bit more poetic than mathematical sometimes. Oh, I see.
Starting point is 00:07:16 Because we try to draw. Well, we try to draw connections. Like we talk about quantum spin and we fully admit that these particles are not actually spinning, but they're doing something that is very much like spin. It has a lot of similar characteristics. And so we draw this analogy. And I think this is one of the most beautiful things about physics is trying to describe the unknown in terms of the known. You know, that's what language is.
Starting point is 00:07:38 That's what it means to explore the universe is to express it in a way that we can understand it. And so that's all we can do. Yeah. Are you say you don't understand goobly-goot? I'm saying goobly-gub suggests some lack of understanding or nonsense, whereas in its place, there are some elegant intellectual structures to guide your mind. Oh, I see. You know, potato, potato, elegant theoretical structures, goobly-gook.
Starting point is 00:08:06 It's all, you know, different names. But so to the end of the podcast, we thought we would take a trip down to that quantum level and kind of think about a particular, you know, object that I think, we're all familiar with and to sort of challenge our understanding of what it looks like and what shape it has. And most importantly, what size it has down at the quantum realm. And this is something that I have struggled with as a particle physicist, just trying to visualize, just trying to conceptualize it. How do I put this in my mind? How do I think about this so I can get some intuition? Right. And so today we'll be tackling the question.
Starting point is 00:08:42 how big is an electron or how small is an electron oh man is this another potato potato thing it's big and small depending on which country you're in the representatives of the electron union prefer to be called big rather than small oh i see but what does the electron itself prefer Does it see itself as a big or a little? Interview with an electron, a speculative fiction novel by Jorge Chan. Winner of the Nobel Prize in Literature and Physics at the same time. But yeah, you know, electrons are everywhere. They're one of the three fundamental particles that make up everything that we are, that you are,
Starting point is 00:09:27 that planets and stars and galaxies and dust are made out of. And so it's an important particle. And it makes your cell phone work, which, without which, you would probably not be listening to this podcast. Yeah, and it sort of sits at the frontier of particle physics. Our goal is to explain everything in the universe in terms of the smallest bits and pieces, the tiniest, roundest Lego pieces anywhere.
Starting point is 00:09:50 And as far as we know, these are the smallest bits. And so we wonder, like, is it made of something smaller? How small is this thing anyway? Yeah. What's the size of an electron? I guess that's a question we haven't really talked about before. We just sort of talk about electrons and what they can do. and what they do, and we know they're small,
Starting point is 00:10:07 but I guess the question here is how small it is, or how big is it not? How big isn't it? Yeah. And like with many of these mappings to the quantum realm, I'm pretty sure you're going to be dissatisfied with the answer. Because did you misname something again? Is it not really called?
Starting point is 00:10:24 Is it like an electron? Not really an electron? Well, I don't want to give away the end. You'll have to stick around for another half hour. Well, this is a question that, as always, we were wondering, wondered about and what they knew about the answer to this question. So as usual, Daniel went out there into the wilderness of the streets of Irvine, California, and asked people how big they
Starting point is 00:10:47 thought an electron is. I like the way you make it sound dangerous, like I'm hacking my way through the jungle. I think talking to perfect strangers sounds terrified to me. Well, here's what people had to say. But before you hear these answers, think to yourself, what would you guess is the size of an electron. Very small. I know like a couple billion atoms can fit on a period in a book, so an electron is trillion, quadrillion, I don't know. Centimeter is like small, like smaller than that? Best guess like 10 to minus 100, like a hundred, like a hundredth of a nanometer? 10 to the minus 16? Well, I guess it's when its way function falls off, is one over E or something
Starting point is 00:11:30 like that? Is that how we want to call it? What's 13.6 e? TVs and nanometers. It does red stuff, so a couple hundred nanometers. Let's do with that. All right, cool. Also, no idea. Best guess. Not that big.
Starting point is 00:11:45 10 to the negative, I don't know, 11 or 12 or something like that. Like, yeah, meters. All right. Some pretty, I feel like pretty educated answers. Like some people were talking about electron volts even. I like the guy who says smaller than a centimeter. Like, yeah, that's true. Yes.
Starting point is 00:12:03 And also correct. Yeah, definitely correct. No, we shouldn't make fun of these people. They are giving us their time and their energy. And so it's fun just to know what people have in their minds. And I think one of the common answers is like 10 to the minus a pretty big number. But yeah, no, I thought they were pretty. I guess you were at a university.
Starting point is 00:12:23 So maybe a lot of these folks had just taken physics or something. But, you know, if you asked me, I don't know if I would guess with exact figures or units. Well, it's interesting because if you asked me, I don't know what I would say. It's a tricky question, even what is the meaning of the question? Like, what does it mean for the electron to have a size? So it's complicated. So if someone interviewed you on the street and asked you this question, you'd be like, let's sit down for a couple of hours. Exactly.
Starting point is 00:12:51 Let me pull out my whiteboard. I say, thank you for asking that question. And you see the panic in their eyes as they. I've been waiting all my life for a perfect stranger to ask me this. They would feign a phone call and run away quickly, yeah. All right, well, let's get into the trying to answer this question. And I guess the first thing that you're telling me is that this is even, it's kind of almost a philosophical question.
Starting point is 00:13:13 It's like a tricky question in itself to ask, what is the size of an electron? Yeah, and you have to be really careful about what you're doing when you're asking a question that you're used to asking about macroscopic stuff and then applying that to microscopic stuff. You have to be really careful about what you mean and what exactly it is you're trying to learn. You know, like when we think about a ball moving through space, we can talk about it's velocity.
Starting point is 00:13:37 Cool. But when you want to talk about the velocity of an electron, it's more complicated because it doesn't have like the same kind of path. And so its velocity changes and sometimes you can know it. Sometimes it's unknown. And so, you know, there's an analogy you can make there, but you have to be careful about exactly what you're asking. And the same is true when you ask about the size of something super duper tiny. Right. And especially when you ask about the size of a single thing.
Starting point is 00:14:02 thing, right? Like, what is it, what does it even mean to ask about the size of anything? Is it like how much space you occupy? Is it like the, my longest dimension? Is it the distance between, you know, one side of me to the other side of me? I think that's it. I think it's the distance between your edges. And so you have a size if you have edges that don't touch, right? If there's a meaning to, like, there being a left of you and a right of you, and your size is the distance between them. You know, we have a, a meter stick. How big is it? Well, the left side is one meter from the right side. So that sort of makes sense, right? And this all sounds, you know, obvious, but it's going to be important when we get
Starting point is 00:14:42 to the quantum realm to be thinking about it in the same, same sort of set of ideas. Right. Yeah, I guess you got to think about what makes it a thing and when does it stop being a thing, and then you calculate kind of the distance between the edges of what is and what is not a thing. Yeah. And so you answer the question like what does size mean well it's the distance between the edges and that immediately brings you to that other question what is the edge like what is the edge of a meter stick or the edge of a banana how do you define where that stops and that's not so easy oh man you just make me imagine an endless banana and I salivated a little bit that's a whole universe for you right there man maybe the whole universe is just one banana we are all just binaninos in a banana yeah we should
Starting point is 00:15:27 start that in the rest of you know olive garden has the endless bowl of salve you endless breadstick, we can start selling the endless banana. But anyways. So where is the edge of the banana, right? You would think, oh, I'm looking at it. I can tell where it stops. And you either you poke it or you're just looking at it. It sort of gives you a sense for like where the edge is. It doesn't have a fuzzy edge. Like it stops. All the atoms that make up the banana are kind of stuck together. And at some point, there aren't any more of the atoms that make up the banana. Yeah. Although if you zoom in close enough, right, everything that's not at absolute. zero is has a bit of a fuzzy edge. You know, it's like boiling off atoms. Like the reason you can smell a banana is that there are volatile molecules on it that are always leaving. And so zoom in close enough and there's a bit of a fuzzy edge there.
Starting point is 00:16:13 But still, you can like take a stick and you can poke the banana with your tiny stick and you can ask like, when does the banana give me resistance? Or is the edge of it is sort of like, you know, where does it push back? Okay. So that would be the edge of like an object, a microscopic option. you're saying it has to do with when it no longer interacts with you in the same way as the rest of the banana. Yeah.
Starting point is 00:16:34 And there's an important idea there, I think, which is it's not where the stuff of the banana ends. It's where the banana's forces push back. Because, you know, the banana itself is mostly made of these, we'll talk about it in a minute, but much smaller particles. And the stuff of the banana, the thing that gives it its volume is the forces, right? If there were no forces between these particles, they would collapse to a much smaller pile. Like, if you just made a pile of all the atoms inside the banana, it would be almost invisible. Most of that volume comes from them spacing each other out by the forces.
Starting point is 00:17:09 So it's really the forces, the pushing back that gives the banana its volume and therefore its size. I see. You wouldn't measure it as between the center of the rightmost atom of the banana to the center of the leftmost atom of the banana. You would extend that a little bit to include, like, when that atom starts pushing back another atom. tries to poke through the banana. Precisely, because if you bring your stick nearby, then the farthest, the most extreme atom in your stick is not going to touch the nucleus of that atom in your banana.
Starting point is 00:17:40 They're going to push against each other before they touch. And so that's what I think of sort of the edge of the banana is that force field that sort of protects it from, you know, external forces. Okay, so you're saying as a physicist, you would define the size of something as the edges of it. and the edges you would define as when they stop pushing other things from going through it. Yeah, so really it's more about interactions than it is about matter itself. In particle physics, we think a lot about particles and forces matter and interactions.
Starting point is 00:18:12 And I think the size of something really depends more on its interactions than on the stuff that's inside of it. And that makes sense because if you want to know the size of something, you want to know it for a reason, usually, right? Like, you want to see if the banana fits inside of a special, you know, banana carrying case that you are designing. You need to know, you know, not when the set, where the centers of the atoms are, but you want to know, you know, if you can fit the banana inside the case. That's exactly it. But it already raises some problems. Like, what if you had a blob of dark batter, the shape of a banana? How big is it?
Starting point is 00:18:47 Well, if you can't really interact with it, if you could, like, put your finger through it, then. You know, does that mean that it's a banana-shaped blob of dark matter is smaller? It doesn't have a size maybe even. Boy. Yeah, so it gets tricky pretty quickly. This thing, which we thought was simple, it actually turns out to be kind of subtle. Yeah, it's feel back the answer to this question and also get into how big an atom is. And then we'll get into how big an electron is.
Starting point is 00:19:14 But first, let's take a quick break. December 29th, 1975, 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.
Starting point is 00:20:01 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. 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.
Starting point is 00:20:41 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 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?
Starting point is 00:21:00 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. 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.
Starting point is 00:21:31 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,
Starting point is 00:22:11 Apple Podcasts, or wherever you get your podcasts. All right, Daniel, so it seems like the question of how big something is is kind of fuzzy in itself. And so maybe a good way to kind of tackle it is to start with the next level down from a banana, which is like how big is one of the atoms in the banana? So remember that we decided that if we're going to talk about the size of the atom, we're not going to ask where is the stuff inside of it? We're going to ask, where does it push back when it's poked? And to figure that out, it's helpful to sort of imagine a whole pile of atoms packed together.
Starting point is 00:22:56 Here you have, you like, imagine the banana is sort of like a crystal, you know, it's like closely packed atoms of the banana. And here it's determined, again, by the interaction between them. Like, how closely packed are they? Depends on how much they resist being squeezed together. And in this case, for an atom, it's, you know, for a banana or for other stuff, it's pretty small. It's like, you know, 50 to a couple hundred trillionths of a meter. Is what, how you would define how big an atom is? Yeah, that's like the separation between the center of one atom and the center of another atom,
Starting point is 00:23:32 depending on the material. And different things can sort of pack more tightly together than other things like hydrogen. You can squeeze it down to like 30 trillions of an atom between protons. But if you're packing lead together, for example, it's almost 200. trillionths of a meter between sort of the centers of the nuclei. It's like if you were trying to measure the size of a bunch of marbles, you would stick them in a container and see how many you can sort of cram together. And that kind of tells you the size of each marble.
Starting point is 00:24:03 Yeah, the distance between the centers of the marbles there. You pack them as closely as you can, and then you measure the distance between the centers of the marbles. Is that actually sort of, because, you know, when I think of an atom, I think of like, you know, like the popular culture drawing of an atom, which is like, you know, little balls in the center and then electrons flying around in orbit, you know, and I know that, you know, they're actually like electron clouds, but even the clouds have sort of a size, right? They're drawn as little balloons that stick out of this center. Is the size, is the packing size that
Starting point is 00:24:36 you're talking about? Like how many you can cram in a banana the same as the size of those, like electron clouds. Yeah, it's very closely connected and for a reason. Those electrons are the reason that the atoms don't pack more closely together. Like you bring two hydrogen atoms near each other. It's the electron clouds that determine how closely they get together because they form like a covalent bond and make an H2 or something like that. And so it's those electrons that determine the interactions between the atoms and determine their spacing. And it's when those two things start overlapping is when they can no longer really get closer together. So, yeah, the size of the electron cloud is very closely connected to the size of the atom.
Starting point is 00:25:17 It really is what defines it. They're always interacting, right? No matter how far apart there are. Like, if I had an hydrogen atom here and you had a hydrogen atom in Jupiter, technically they're sort of repelling each other, right? Or and or attracting each other or not. They definitely do feel each other. You're right.
Starting point is 00:25:32 The extent of the electromagnetic force is infinite. So there are electrons in Alpha Centauri that are pulling on you or pushing on you or depending on whatever they're doing. Technically touching you, right? You're being touched by an Alpha Centauri right now. Ooh, I just got chills down my spine. A little bit to the left, please. Yes, thank you. That's the spot.
Starting point is 00:25:55 Scrash that itch that I've had. Yeah, well, it's a tricky concept. You're right. If we're going to define size by sort of how you respond when you get poked, then you're right. you're being constantly poked by everything in the universe. Wow. Even the stuff like a billion night years away. Yeah, it is everything in the universe is feeling you.
Starting point is 00:26:15 Although, you know, there's a time delay there. So the stuff in Alpha Centauri is only feeling stuff, is feeling where we were a long time ago. That's a separate issue. So my size depends on time as well. Jeez. But, you know, those things are pretty negligible. And so you can think about like when these things really,
Starting point is 00:26:33 have an effect. If you probed, if you shot an electron at hydrogen atom, when would it deflect the electron? And if you shot a meter to the right, it wouldn't change the path of the electron really at all. It would, but it would be very little. It would be very little, be negligible. But then when you hit it right on, then it's going to bounce right back. And so you can use that to sort of get a sense for what is the meaningful sort of charge radius of a particle. And you're right, there's no crisp edge there. So there's a small complication there also because it turns out that the size of something depends on not just what you poke it with, but how hard you poke it. Like if you poke an atom very gently, it'll seem bigger because you'll notice smaller deflections further away.
Starting point is 00:27:21 If you poke it very hard, it'll actually seem smaller because you'll overpower the electrons on the outside and only see the nucleus on the inside. There's no point at which it goes to zero, though. You're right. Right, yeah. So it's kind of fuzzy and maybe kind of arbitrary. But you're saying it's like when you would actually feel the force of that electron. That's when maybe you would say, all right, it's sort of impinging on it, which means it's sort of bumping up against it. And it's not totally arbitrary.
Starting point is 00:27:48 Like when you squeeze atoms together, they settle in at a certain distance from each other. So that tells you what the equilibrium location is for the distance between atoms. And that, I think, is a reasonable way to define the size. But, you know, you're right. You have to think about, like, what am I meaning by size in this context, in this other context? This basic thing we think about, like, should be obvious to talk about is it turns out to have a lot of wrinkles to it. All right. So that's kind of how you would define an atom is when it starts to push back another atom and how much when you crad them inside of a box, you know, what's the natural spacing that they have between them.
Starting point is 00:28:23 And you're saying it's sort of related to those electron clouds, which is kind of how far away the electron goes from the nuclei, right? from the nucleus. Okay, so that's an atom, but I guess it gets tricker when you talk about individual particles. And so let's go down one more level to the proton inside of the nucleus. How big would you say a proton is?
Starting point is 00:28:44 This is a wonderful question. And, you know, if you're breaking open the atom, if you're shooting electrons at the atom, it's going to get repelled by the electrons on the outside of it. But if you give them enough energy, then they can sort of penetrate through there. And then you can start to probe the proton inside there.
Starting point is 00:29:00 And you can ask, like, how big is this thing? And so we do that exactly. We shoot electrons at protons or hydrogen atoms or it doesn't really matter if the electron is there anymore because the probe we're shooting with has so much energy. And we see where does it bounce back and where does it sort of stop bouncing back? And that gives us a sense for how big the proton is. And so we actually have a number for that. But it's tricky because the proton is also made out of things inside of it, sort of like the atom itself.
Starting point is 00:29:28 It is. protons are made of smaller bits that are sloshing around inside of it. Those are the corks. But remember that we're trying to define the size of an object, the proton in this case, not by where the stuff is inside it, but where it pushes back. And the quarks hang out together and push back against the other protons. So if we use our definition, it's the distance between the protons that's going to determine the size of the protons.
Starting point is 00:29:55 And that's connected, of course, to how the corks are arranged, how they're happy to be inside the proton. The proton is sort of like a cork atom. I see. If they were comfortable being a mile apart, you know, like if you try to split them more than a mile or squish it more than a mile, they would prefer to be a mile apart from each other.
Starting point is 00:30:12 Now you would say the size of those two electrons, quartz is about a mile. Oh, the size of the proton that's made up of those corks, yeah, would be about a mile. But, you know, we have nuclei and they have got protons and neutrons inside of them, and each one is like its own little particle. They get squeezed together,
Starting point is 00:30:28 They hang out. They keep their own little particle nature. And so it's just like packing marbles together. You can ask about the distance between the center of one proton and another, or proton and a neutron. That's what we think of as the size of the proton. How much can you pack in the quarks that are inside of the proton? Yeah. And that's a really crazy number.
Starting point is 00:30:46 That's like one quadrillionth of a meter. It's a really small number. And that's smaller than a nanometer for sure. It's smaller than a centimeter as well. it's smaller than a mile apparently as well so that's pretty small
Starting point is 00:31:04 that's pretty small yeah like how big is that in relation to like the size of an atom well an atom is you know like 10 to a hundred-ish trillions of a meter so this is one quadrillionth
Starting point is 00:31:17 of a meter so it's like one 10,000s or 100,000's the size of an atom so it's very small compared to the atom compared to the electron of the proton is super tiny. Okay, wait, so we have an atom,
Starting point is 00:31:31 and how about just the nucleus of the atom? How close together are those protons and neutrons in the nucleus packed together? Those are very tightly packed together. And again, remember, that's because that's sort of how the size of the proton is determined. It's like, how do those things cluster together? And so the size of like, if you have the nucleus of an atom
Starting point is 00:31:51 with 100 protons and neutrons in it, it's not that much bigger than one proton. It's like packing above those marbles together. So it's going to be order of magnitude quadrillions of a meter. Oh, wow. So that's why they say like an atom is mostly empty space because what you would say is the size of it. Actually, the nucleus is like this tiny little bit of it inside.
Starting point is 00:32:13 Yeah. And the way that they probe this is two different ways. One is they shoot an electron at a proton. But sometimes also they just look at an atom. They just watch an atom sitting there. It's got a proton and an electron. and the electron is whizzing all around. And sometimes, this is super weird,
Starting point is 00:32:31 sometimes the electron goes inside the proton. Like in a quantum mechanical way or like it actually goes through? Ooh, what's the difference? Quantum mechanics is reality, dude. Like if you were to, you know, I mean like if you were to open the Schrodinger's box and you would suddenly find it inside of the nucleus? Yeah, the electron in one of its states has non-zero probability density to be inside the proton.
Starting point is 00:32:58 And when this happens, it's sort of like partially cancels some of the charge pull of this thing because you have the electron now inside the positive atom, and then it escapes. But depending on the size of the proton, it escapes, this happens more or less often. And so you can measure how often the electron is inside the proton, and that tells you how big the proton is, because the bigger the proton is, the more often this happens. So this is another way we sort of get a sense for how big is the proton. I see. Using like probability.
Starting point is 00:33:31 Yeah. Like if you throw a bunch of darts at it, only sometimes you hit the proton, then that sort of tells you the size. Yeah, exactly. And that's actually the most sensitive test, basically using the hydrogen's own electron, like pass it through the proton and give you a sense for how big it is. It's crazy. Well, all right. So a proton is about, you're saying one, 10,000th of the size of a typical atom. That's pretty small because atoms are pretty small in themselves.
Starting point is 00:33:58 All right, so let's get down now to the last level, which is how big is an electron. And I imagine that's going to be even smaller, but we'll get into that. But first, let's take a quick break. December 29th, 1975, 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.
Starting point is 00:34:37 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.
Starting point is 00:35:07 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. 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.
Starting point is 00:35:41 Isn't that against school policy? That sounds totally inappropriate. Well, 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.
Starting point is 00:35:58 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. Hola, it's Honey German, and my podcast, Grasasas Come Again, is back. This season, we're going even deeper into the world of music and entertainment with raw and honest conversations with some of your favorite Latin artists and celebrities. You didn't have to audition. No, I didn't audition.
Starting point is 00:36:24 I haven't auditioned in like over 25 years. Oh, wow. That's a real G-talk right there. Oh, yeah. We've got some of the biggest actors, musicians, content creators, and culture shifters sharing their real stories of failure and success. You were destined to be a start.
Starting point is 00:36:43 We talk all about what's viral and trending with a little bit of chisement, a lot of laughs, and those amazing Vibras you've come to expect. And of course, we'll explore deeper topics dealing with identity, struggles, and all the issues affecting our Latin community. You feel like you get a little whitewash
Starting point is 00:36:58 because you have to do the code switching? I won't say whitewash because at the end of the day, you know, I'm me. But the whole pretending and cold, you know, it takes a toll on you. Listen to the new season of Grasasas Come Again as part of My Cultura Podcast Network on the IHartRadio app, Apple Podcast, or wherever you get your podcast. All right, Daniel, so now we're down to one of the fundamental particles, the electron,
Starting point is 00:37:28 and we're asking the question, how big is it, or how small isn't it? How big and isn't it? I'm out of negatives here. And I guess what we're going to talk about is sort of applies to quarks as well, right? Because we're now talking about single particles, not like clusters of particles. Yeah, and remember that our theory is very hierarchical. We start with matter and then we go to molecules. We go from molecules to atoms and from atoms to protons and electrons and then to quarks and electrons.
Starting point is 00:38:00 And we sort of have shells inside shells inside shells. And so this is sort of our current level of knowledge and we can ask like, are these particles that we see? Are they the smallest possible thing or is it possible there's something else inside them? So you're right that quarks and electrons are sort of as far as we've gone. And so in some sense asking how big are they, is asking, are they the end? the end. Are they the tiniest, smallest possible thing? Or are they possibly made of something smaller? Oh, I see. Because if you can split them, that means there's something smaller inside. I guess that's pretty obvious. That sounds deep, and it is deep, but it's also kind of obvious. Like, if you can break it
Starting point is 00:38:39 into smaller pieces, then it's therefore made of something else. As far as we know, quarks and electrons are not yet made of something smaller. But that doesn't tell you necessarily how big they are, right? they could be the smallest possible thing and still have a finite size. Right. They could be... The Legos of the universe. The Lego, yeah. It could be the smallest Lego you can have, but that can be smaller,
Starting point is 00:39:01 smaller big. That could be smaller big. And that's fascinating when you learn a number about the universe. Like, let's say we somehow proved that quarks and electrons are not made of anything smaller. They have the smallest Lego blocks. And we measured their size. Then we'd know something really deep and basic about the universe.
Starting point is 00:39:17 Like, it's made of Legos this size. you'd have to wonder, like, well, why that size and not something else? What does that tell you about the universe to know that fundamental fact? Yeah, did you know there are Legos that are smaller than the single unit Lego? What? Like, you would think the smallest Lego is just like one square with one circle on it, right? Are you saying people have smashed the Legos together to make sub-legos? They discovered the constituent pieces of Legos.
Starting point is 00:39:43 No, yeah, this is kind of weird and probably not consequential, but, they make smaller pieces. They make pieces that fit inside of the hole that some of the single circle Lego pieces have inside. Oh my God, you have just violated the standard model of Legos. Noble Prize, please. You got the Gooply Goop Prize from that one.
Starting point is 00:40:06 Anyways, so yeah, so let's talk about how big an electron is then. Let's use that as a single particle example. And does it even make sense to talk about the size of a single particle, Daniel? It's hard to talk about the size of a single particle if you haven't measured the stuff inside of it because we've talked about the size of atoms and protons based on like how happy the stuff inside of it is to be next near each other. Like how closely does it pack? So for a fundamental particle, you have to go back to like the to poking it and be like, well, if I poked an electron with a stick, where would it push back? But that's sort of unsatisfying to me.
Starting point is 00:40:43 couldn't I just, you know, pack a bunch of electrons in a glass jar and see, wouldn't that tell me sort of the size of it? Like how comfortable an electron is to another electron or to a proton? Wouldn't that sort of tell you the sort of the size? Just like we did with the marbles and the atoms? Yeah, that sounds like a really fun experiment. I want to take like a gas of pure electrons and squeeze it down together and see what happens. The problem is that there's not like a clear answer. Like the harder you squeeze, the closer they get together.
Starting point is 00:41:12 there's not like an equilibrium like with protons or with atoms because these are all just negatively charged particles there's no chill state where they're like hey you're there, I'm here all is good and so instead you want to like take them and like poke them like well if you poke them
Starting point is 00:41:28 with an electron then they bounce back for sure but what if you poke them with neutrinos then they don't bounce back at all or what if you poke them with dark matter then they don't bounce back and so you're back to this like fuzziness of like you know if it depends on how
Starting point is 00:41:42 how it's pushing back, then it depends on what you're poking it with. And then size isn't something that's like inherent to the object. It's about the interaction, which means it depends also on the thing you're interacting it with, which is so frustrating. Oh, I see what you're saying. Like, if I had a cloud of electrons, you could maybe talk about where the cloud is and where the cloud isn't, where the electrons are and where there aren't. But with one single electron, it's hard to say where it ends.
Starting point is 00:42:08 It's hard to say where it ends. Like, is there a left side to the electron and a right side to? the electron, are those things even the same thing? Because it depends on what you're trying to touch it with, right? Like if you're trying to touch it with another electron, it would maybe repel at a certain distance. But if you try to poke it with a proton, then it would maybe attract at a different distance. Yeah, well, not so much electron versus proton because they both feel electromagneticism,
Starting point is 00:42:33 but what if you used a different force? If you used like the weak nuclear force or if you used gravity or if you used electromagnetism, then the size you would get from an electron is different. Oh, I see. You're saying to a neutrino, an electron has no size. Yeah. It doesn't, like, I don't care. Like, the neutrino doesn't care.
Starting point is 00:42:53 A neutrino would pass through a cloud of electrons and have a much lower chance of interacting than another electron would. Like, it wouldn't even know it's there. Yeah, or dark matter, right? Poke a pile of electrons with a stick of dark matter. You're going to get almost no interactions. Or maybe no interactions. We don't even know about dark matter.
Starting point is 00:43:10 And this is the problem. It makes sense to define size in terms of interactions, like where does something push back? But it also is troublesome because then it depends on what you're pushing on it with. So that's kind of a problem in defining the size of an electron because it depends on what you poke it with. So then we try something else. We say, well, let's think about it like quantum mechanically. Like we've talked about where the electron is and it's defined by like its quantum mechanical wave function. And, you know, you were talking about like those balloon shapes where the electron is.
Starting point is 00:43:39 you know, what's the sort of the most you can localize an electron? Like, what's the size of that quantum packet? You want to think about it like as a tiny quantum object. That's another way to try to grapple with it. Because there are probability curves, right? Like, you know, where the cloud is fuzzy tells you that the probability that the electron is there is small, but where the cloud is kind of thick, it tells you that there's a high probability that the electron is there.
Starting point is 00:44:03 But that doesn't really give you any insight because that size can be almost anything. It depends on the uncertainty principle. If you know almost nothing about the velocity, the momentum of the electron, then you can know exactly where it is, which means it has like zero, that quantum mechanical packet has zero width. And on the flip side, if you know everything about its velocity, then its packet is infinitely wide. It exists everywhere in the universe simultaneously. You have like a universe-sized electron. So that's intellectually not that satisfying either. But what if you assume an electron is just standing still?
Starting point is 00:44:40 Like when you're trying to measure your kid, how tall they are. And it's impossible because they keep moving. But what if you can get them to stand still? What would that happen? Would you be able to then get a pretty accurate size? If you're measuring the velocity of the particle, you're getting it to stand still, has no velocity. And you say it has zero velocity.
Starting point is 00:44:57 Then it has infinite size. Because you can't know the product, remember the product of the position and momentum uncertainty has to equal a certain number. And so if you're narrowing down the speed of the electron really, really well, that means you don't know anything about where it is. It's an infinite plane wave. Size is only a distance, whereas, you know, in particle physics, distance is kind of intertwined with time as well in velocity.
Starting point is 00:45:23 But then on the flip side, if you say, I don't care at all about how fast it is, I just want to know where it is, then you can localize it as much as you want. You can make it infinitely narrow. And so that also doesn't give you any sense of like the size of the electron. So strike two, we can't use poking or quantum mathematics. So does that mean that the electron has no size? That it's impossible to define the size of an electron? It kind of does currently.
Starting point is 00:45:49 I mean, in our theory, the way we actually use it is we assume the electron has no size at all. It has zero volume. It's just like a point in space. The left is the right. The top is the bottom. The back is the front. There's no extent to it at all. It's sort of mathematically, and because of all the things we just talked about, I guess, that's true.
Starting point is 00:46:11 Yeah, you can't measure the size of an electron. It doesn't make any sense to think about it. Yeah, in our theories, we just put zero because we assume that there's nothing there. We have no way to really see the size of the electron. But, you know, we do continue to try. We do smash particles at the electron, hoping that we'll see it break open, hoping that we'll see other little particles come out of it. But I guess getting back to the size of the electron itself, I mean, it's not like, it has no size because it's not a mile wide. Like, would you even say that the electron is, all electrons are a mile wide?
Starting point is 00:46:45 I don't know what to say for the size of the electron, you know, and that's why I predicted, I think correctly, that you'd be unsatisfied with my answer. Oh, my God. It's not really, it's, I mean. You can't tell the future, Dan. I can't. Yeah, well, I can't in this case. Like, I think the way I think about it currently. is as a point, but I also know that that makes no sense because, like, how do you have something
Starting point is 00:47:08 that has mass, but has no volume? Because it has infinite density, which is nonsense. Right, because electrons have mass. They have mass, and they have charge. And, like, where does that charge go? Where is it in the electron if it has no volume? We're just used to thinking about stuff as having size, as having volume. So to imagine, like, that the basic building blocks of the universe themselves are of zero volume is really weird. But I guess maybe, you know, that's the theory of it. But practically speaking, I mean, we can talk about what's practical to you and me is like
Starting point is 00:47:41 electromagnetic forces, right? I know it doesn't make sense in terms of neutrinos or dark matter, but kind of what's practical is electromagnetic forces. And so couldn't we sort of maybe give a practical size of the electron because of that? Like what's the closest to electrons in one atom, how close can they get to electrons in another Adam, wouldn't that sort of give you a general size? Yeah, and we've done that. We've, like, pounded electrons near each other, try to get them as close together as possible.
Starting point is 00:48:10 And so far, we haven't found a limit. Like, there's no point at which the electrons will not get closer to each other. And so far, we've gotten down to about 10 to the minus 20 meters. And you do that by shooting really high energy electrons at other electrons and try to get them really close together. So that's as far as we could tell. We can't tell the difference between the electrons have no volume and they have some volume that's smaller than 10 to the minus 20 meters.
Starting point is 00:48:37 We can't tell the difference. So far, they look like they're point-like. We have some sort of limited resolution there in our ability to probe. So what happens if the whole universe was just like a proton and an electron? I guess the electron would orbit the proton. That's what hydrogen is. Yeah, the size of the hydrogen comes from their interactions, right? And most of the volume of all the stuff in the universe comes from the interactions,
Starting point is 00:49:00 not from any actual volume of the particles that make them up. All right, you're right. This is very unsatisfying. I need a banana, man. Well, that's satisfying to me that at least I was right about that. But it's a really fun puzzle because I think it's interesting to try to grapple with the quantum realm and try to understand what are the limits of our ability to map these concepts, size and mass and charge and velocity, down to these tiny particles that end up.
Starting point is 00:49:26 end are the reality, are the truth about our universe. Yeah, and I think it's interesting how, you know, you sort of put it, that it's all about the interactions, you know, and it's hard to think about an electron not having like a surface or, you know, an edge where it's no longer an electron. And it all sort of depends on what you're trying to look at it with, you know, like if you're trying to look at it with neutrinos, then you wouldn't see anything at all. Yeah. But if you looked at it with electrons, it would feel like a certain size, maybe. Yeah. And this is. connected to some of the other puzzles we talked about like does the electron actually spin we know
Starting point is 00:50:01 that it's either a point in which case doesn't make sense for it to spin like a point literally cannot spin or that it's super tiny but if it's super tiny and it has a surface then it's spinning so fast that that surface is moving faster than the speed of light so at some point it like it doesn't even make sense for it to have a non-zero size at some point nothing makes sense Daniel life is meaningless and that's usually about 45 minutes in every episode. The incredible thing is that we can understand it at all, that we can take these ideas from our everyday experience of like eating bananas and throwing balls around, and that
Starting point is 00:50:38 it can give us any guide into the microscopic, you know, because the microscopic is so weird, so alien, it's incredible it works at all, that I even have a job. But yeah, but that's the thing. It was we don't understand it, but yet at the same time, we're able to, you know, predict it and describe it with math. But that doesn't mean we understand it, right? That's what understanding is, as far as I know. I don't know any deeper level of understanding.
Starting point is 00:51:03 I mean, you pass it off to the philosophers, and you can ask them, like, you know, what does it mean, man? But in the end, what we're trying to do is physicists is just sort of describe accurately the world we see around us, build a model in our heads that makes sense, describe all this unknown in terms of the known. That's all the understanding we can hope for.
Starting point is 00:51:22 Well, I guess what I mean is, like, at some point, proton was a proton, and we had to math to describe it, and we thought we understood it, but then it turned out that there was more to the proton than we thought, and we didn't actually understand the proton. It was made out of quarks, for example. So I feel like, you know, you have a mathematical description of stuff, but you don't know if you're really understanding it to the fundamental level. And all of these mathematical descriptions, they work up to a point. Like your idea, thinking about a proton as a fundamental particle, as a point particle, that mostly works. It works
Starting point is 00:51:54 unless you get up to really high energies, energies where you can see inside the proton because the energies are greater than the bonds that are holding the proton together. And so as we keep pushing to higher and higher energies, we're looking deeper and deeper into the real truth, the smallest scales of the universe. And that's what limits how small we can see.
Starting point is 00:52:14 It's the energy with which we probe it. And that's why building a bigger super collider would let us maybe see whether the electron had bits inside of it. Yeah. Keep funding physics. Daniels. Hey, I'm on message, if nothing else.
Starting point is 00:52:29 Keep sending those checks, please. If you have to pick between donating to bananas or fundamental physics, you know where I stand on that. Bananas, right? Because bananas are made out of fundamental parts. All right, well, we hope you enjoyed that. And maybe the next time you take a bite out of a banana or your fruit of choice, maybe think about what it actually means to take a bite. I feel like we've thrown everything into question now, Daniel. Like, what does it even mean to take a bite and to, when do my teeth end and when does the banana begin?
Starting point is 00:52:58 I don't know, but every banana you've ever eaten is made out of zero volume particles. Chew on that and think about it until next week. Thanks for joining us. See you next time. 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,
Starting point is 00:53:26 or email us at Feedback at Danielandhorpe.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,
Starting point is 00:53:40 Apple Podcasts, or wherever you listen to your favorite shows. 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.
Starting point is 00:54:18 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 her gone.
Starting point is 00:54:51 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. I'm Dr. Scott Barry Kaufman, host of the psychology podcast. Here's a clip from an upcoming conversation about how to be a better you. When you think about emotion regulation, you're not going to choose an adaptive strategy which is more effortful to use unless you think there's a good outcome. avoidance is easier ignoring is easier denial is easier complex problem solving takes effort listen to the psychology podcast on the iHeart radio app apple podcasts or wherever you get your podcasts this is an iHeart podcast

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