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

• 0:09
  Speaker 1: Hey, or hey, you're a visual artist, so I have
• 0:11
  Speaker 1: a question for you about how you visualize things. Well,
• 0:15
  Speaker 1: first of all, thank you for calling me an artist.
• 0:18
  Speaker 1: Cartoonist don't usually get that kind of respect. But do
• 0:21
  Speaker 1: you mean can I draw my answer? Yeah, maybe when
• 0:25
  Speaker 1: we upgrade this podcast to a YouTube channel, But until then,
• 0:29
  Speaker 1: here's my question. What is the biggest distance that you
• 0:33
  Speaker 1: can visualize that you can sort of see in your mind? Well,
• 0:36
  Speaker 1: I think anything bigger than the distance between my bed
• 0:40
  Speaker 1: and the fridge feels like an infinity. I guess maybe
• 0:44
  Speaker 1: like the biggest distance that I can wrap my head
• 0:47
  Speaker 1: around would be maybe like the size of the solar system,
• 0:50
  Speaker 1: you know, Like I think I have a intuitive sense
• 0:53
  Speaker 1: of that, but maybe anything bigger it just kind of
• 0:56
  Speaker 1: blows my mind. All right, So then turn it around.
• 0:58
  Speaker 1: What is the small all this distance that you can visualize?
• 1:02
  Speaker 1: Probably the width of a thinly sliced banana. Feels like
• 1:08
  Speaker 1: maybe you should have had a snack before we did
• 1:10
  Speaker 1: today's podcast. I am Rhammad, cartoonists and the creator of
• 1:29
  Speaker 1: PhD comments. Hi, I'm Daniel. I'm a particle physicist and
• 1:33
  Speaker 1: I don't eat bananas no matter how then you slice
• 1:36
  Speaker 1: them really you're anti banana like you avoid them. I'm
• 1:40
  Speaker 1: anti bananite, yes on the air. I didn't know that.
• 1:45
  Speaker 1: Oh my god, how do we even get along all
• 1:47
  Speaker 1: these years? I don't know if we I can continue
• 1:49
  Speaker 1: doing this with you anymore. So if you if you
• 1:51
  Speaker 1: get him in a salad, you picked them out or something.
• 1:54
  Speaker 1: How far puts banana in a salad? What are you
• 1:56
  Speaker 1: talking about? You were offending salads? How far this is
• 2:01
  Speaker 1: anti bananas? Goes go? Daniel, Well, let's see, if I
• 2:06
  Speaker 1: was dying of starvation next to banana tree, I would
• 2:10
  Speaker 1: eat some bananas. I'll put it that way. I would.
• 2:12
  Speaker 1: I see. Oh man, you don't know what you're missing.
• 2:16
  Speaker 1: But for those of you who are not anti banana,
• 2:20
  Speaker 1: welcome to this podcast. Daniel and Jorge Explain the Universe,
• 2:24
  Speaker 1: a production of Our Heart Radio, and banana lovers and
• 2:26
  Speaker 1: banana haters are all welcome on this podcast because we
• 2:31
  Speaker 1: only the lovers, because we all share the love of
• 2:35
  Speaker 1: the universe and the mystery is and the incredible cosmic
• 2:38
  Speaker 1: questions like how can anybody stand to eat a banana? No? Like?
• 2:43
  Speaker 1: How big is our universe? And does it all make sense?
• 2:45
  Speaker 1: Should ever rebody Daniel that bananas are part of the universe.
• 2:48
  Speaker 1: If you love the universe, technically you love bananas. But
• 2:51
  Speaker 1: welcome to our podcast, in which we do try to
• 2:54
  Speaker 1: explore everything around us, including bananas and other delicious or
• 2:58
  Speaker 1: non delicious items, and explore lane how it all works
• 3:01
  Speaker 1: to you. Yeah, we try to think about the bigness
• 3:03
  Speaker 1: of the universe, the limits of space and planets and stars,
• 3:07
  Speaker 1: but we also like to talk about the small things
• 3:10
  Speaker 1: in life and in the universe, and and sometimes it
• 3:13
  Speaker 1: really stretches your mind right to sort of sort of
• 3:16
  Speaker 1: in one conversation think about how big the universe is
• 3:18
  Speaker 1: and how also how small things are. Yeah, and we
• 3:22
  Speaker 1: try to take you on a tour of the sort
• 3:24
  Speaker 1: of current thinking of scientists. How do scientists think about
• 3:27
  Speaker 1: this stuff? How do they fit the whole universe in
• 3:30
  Speaker 1: their brains? Or what do they visualize when they think
• 3:33
  Speaker 1: about the inside of a black hole? Or how do
• 3:36
  Speaker 1: scientists think about the very very tiny What does a
• 3:39
  Speaker 1: particle look like inside the mind of a party goal physicist? Yeah,
• 3:43
  Speaker 1: because you know, we know that the universe is made
• 3:45
  Speaker 1: out of tiny little particles, and we like to say
• 3:47
  Speaker 1: tiny little particles. But I guess you don't often think
• 3:50
  Speaker 1: about it, what tiny really means. Yeah, we do this
• 3:53
  Speaker 1: a lot when we think about the quantum realm. We
• 3:55
  Speaker 1: try to sort of use the ideas we have from
• 3:58
  Speaker 1: our everyday experience and apply them to particles, apply them
• 4:02
  Speaker 1: to these tiny little bits so that we can make
• 4:04
  Speaker 1: sense of them, because you know, you can't see these
• 4:07
  Speaker 1: things directly, so you have to sort of build a
• 4:09
  Speaker 1: mental picture, and we try to talk about how they
• 4:12
  Speaker 1: have mass and charge, and we even give them you know,
• 4:15
  Speaker 1: labor and spin and other sorts of things that were
• 4:18
  Speaker 1: familiar with from our world. But you have to wonder, like,
• 4:21
  Speaker 1: how well does that really work? Is it really relevant
• 4:24
  Speaker 1: or is the quantum realm just totally alien and we
• 4:28
  Speaker 1: will never really get our minds around it. Yeah, I
• 4:31
  Speaker 1: thought we had already decided that everything looks like Lego
• 4:34
  Speaker 1: pieces down at the fundamental level. They don't look like
• 4:37
  Speaker 1: little blocks with circles that say Lego on them. Well,
• 4:40
  Speaker 1: it's easy to do a test. You know, if you
• 4:41
  Speaker 1: step on them and they cause you great pain, then
• 4:44
  Speaker 1: they definitely are the shape of Lego pieces. I think
• 4:47
  Speaker 1: they make round legos too. Now finally to save parents,
• 4:51
  Speaker 1: But you know, this is all we can do as
• 4:53
  Speaker 1: humans is we can take the ideas we are familiar
• 4:55
  Speaker 1: with and we can try to map them down to
• 4:57
  Speaker 1: the quantum realm to think about this. Yeah, and sometimes
• 5:00
  Speaker 1: that intuition kind of fails, right, or it breaks down
• 5:02
  Speaker 1: when you get down to that quantum realm, that quantum level, right,
• 5:07
  Speaker 1: our ideas of what something is, or how solid something is,
• 5:12
  Speaker 1: or what shape it has, and it all sort of
• 5:13
  Speaker 1: breaks down into kind of mathematical goop right down at
• 5:18
  Speaker 1: the quantum. I think it has a little bit more
• 5:22
  Speaker 1: substance than mathematical GOOPI gloop, but really it's a bit
• 5:27
  Speaker 1: more No, it's a bit more poetic than mathematical sometimes
• 5:32
  Speaker 1: because well, we try to draw connections, like we talk
• 5:36
  Speaker 1: about quantum spin, and we fully admit that these particles
• 5:39
  Speaker 1: are not actually spinning, but they're doing something that is
• 5:42
  Speaker 1: very much like spin. It has a lot of similar characteristics,
• 5:46
  Speaker 1: and so we draw this analogy. And I think this
• 5:48
  Speaker 1: is one of the most beautiful things about physics, is
• 5:50
  Speaker 1: trying to describe the unknown in terms of the known.
• 5:53
  Speaker 1: You know, that's what languages, that's what art is, that's
• 5:56
  Speaker 1: what that's what it means to explore the universe is
• 5:59
  Speaker 1: to express it in a way that we can understand it,
• 6:01
  Speaker 1: and so that's all we can do. Yeah, are you
• 6:04
  Speaker 1: saying you don't understand google Goog? I'm saying googly groop
• 6:09
  Speaker 1: suggests some lack of understanding or nonsense, whereas in its
• 6:13
  Speaker 1: place there are some elegant intellectual structures to guide your mind.
• 6:17
  Speaker 1: I see, you know, potato, potato again, theoretical structures, googly goog,
• 6:23
  Speaker 1: it's all, it's all, you know, different names. But so
• 6:26
  Speaker 1: to the other podcast, we thought we would take a
• 6:28
  Speaker 1: trip down to that quantum level and kind of think
• 6:31
  Speaker 1: about a particular, you know, object that I think we're
• 6:34
  Speaker 1: all familiar with, and to sort of challenge our understanding
• 6:38
  Speaker 1: of what it looks like and what shape it has
• 6:40
  Speaker 1: and most importantly, what size it has down at the
• 6:44
  Speaker 1: quantum realm. And this is something that I have struggled
• 6:46
  Speaker 1: with as a particle physicist, just trying to visualize, just
• 6:50
  Speaker 1: trying to conceptualize it. How do I put this in
• 6:52
  Speaker 1: my mind? How do I think about this so I
• 6:55
  Speaker 1: can get some intuition right? And so today we'll be
• 6:57
  Speaker 1: tackling the question how big is an electron? Or how
• 7:08
  Speaker 1: small is an electron? Oh? Man, is this another potato
• 7:11
  Speaker 1: po typle thing. It's big and small depending on which
• 7:14
  Speaker 1: country here. The representatives of the Electron Union prefer to
• 7:18
  Speaker 1: be called big rather than small. Oh, I see, But
• 7:20
  Speaker 1: what does the electron itself prefer? Does it see itself
• 7:24
  Speaker 1: as a as a big or a little? Interview with
• 7:26
  Speaker 1: an Electron speculative fiction novel by J H winner of
• 7:32
  Speaker 1: the Nobel Price in literature and physics at the same time.
• 7:35
  Speaker 1: But yeah, you know, electrons are everywhere. They're one of
• 7:38
  Speaker 1: the three fundamental particles that make up everything that we are,
• 7:42
  Speaker 1: that you are, That planets and stars and galaxies and
• 7:46
  Speaker 1: dust are made out of um. And so it's an
• 7:48
  Speaker 1: important particle. And it makes yourself phone work, which without
• 7:52
  Speaker 1: which you would probably not be listening to this podcast. Yeah,
• 7:55
  Speaker 1: and it sort of sits at the frontier of particle physics.
• 7:58
  Speaker 1: Our goal is to explain everything in the universe in
• 8:01
  Speaker 1: terms of the smallest bits and pieces, the tiniest, roundest
• 8:05
  Speaker 1: lego pieces anywhere, And as far as we know, these
• 8:08
  Speaker 1: are the smallest bits. And so we wonder, like, is
• 8:11
  Speaker 1: it made of something smaller? How small is this thing? Anyway? Yeah,
• 8:15
  Speaker 1: what's the size of an electron? I guess that's a
• 8:18
  Speaker 1: question we haven't really talked about before. We just sort
• 8:20
  Speaker 1: of talked about electron and what they can do and
• 8:22
  Speaker 1: what they do, and we know they're small. But I
• 8:24
  Speaker 1: guess the question here is how small it is? Or
• 8:27
  Speaker 1: how big is it? Not? How big isn't it? Yeah,
• 8:29
  Speaker 1: And like with many of these mappings to the quantum realm,
• 8:32
  Speaker 1: I'm pretty sure you're going to be dissatisfied with the
• 8:35
  Speaker 1: answer because did you misname something again? Is it not
• 8:40
  Speaker 1: really called? Is it like an electron? Not really an electron? Well,
• 8:44
  Speaker 1: I don't want to give away the end there, you'll
• 8:45
  Speaker 1: have to stick around for another half hour. Well, this
• 8:48
  Speaker 1: is a question that, as always, we were wondering how
• 8:50
  Speaker 1: many people out there had thought about or wondered about
• 8:53
  Speaker 1: and what they knew about the answer to this question. So,
• 8:56
  Speaker 1: as usual, Daniel went out there into the wilderness of
• 8:59
  Speaker 1: the streets of Irvine, California and ask people how big
• 9:03
  Speaker 1: they thought an electron is. I like the way you
• 9:06
  Speaker 1: make it sound dangerous, like I'm hacking my way through
• 9:08
  Speaker 1: the jungle. I think talking to perfect strangers, it sounds
• 9:13
  Speaker 1: terrified to me. Well, here's what people had to say.
• 9:16
  Speaker 1: But before you hear these answers, think to yourself, what
• 9:18
  Speaker 1: would you guess is the size of an electron? Very small?
• 9:22
  Speaker 1: I know, like a couple of billion Adams can fit
• 9:25
  Speaker 1: on a period in in a book, So an electron
• 9:29
  Speaker 1: is Chillian quadrillion. I don't know. Sudden thinkers like small,
• 9:34
  Speaker 1: like smaller than that. Best guys like like a hundred
• 9:40
  Speaker 1: of a nanometer ten to the minus sixteen. Well, I
• 9:44
  Speaker 1: guess it's when it's a way function falls off? Is
• 9:46
  Speaker 1: one over eight or something like that? Is that how
• 9:48
  Speaker 1: we want to call it? What's thirteen point six e
• 9:50
  Speaker 1: v s and nanometers that it does red stuff? So
• 9:55
  Speaker 1: a couple d nanometers? Let's doing that? Also, no idea,
• 9:59
  Speaker 1: best es not that big tend to the negative on
• 10:04
  Speaker 1: all eleven or twelve or something like that. Like all right,
• 10:09
  Speaker 1: some pretty I feel like, pretty educated answers, Like some
• 10:12
  Speaker 1: people were talking about electron volts even I like the
• 10:15
  Speaker 1: guy who says smaller than a centimeter, like yeah, that's
• 10:18
  Speaker 1: that's true, yes and also correct, Yes, it's definitely correct. Um. No,
• 10:25
  Speaker 1: we shouldn't make fun of these people. They are giving
• 10:27
  Speaker 1: us their time, their and their energy, and so it's
• 10:30
  Speaker 1: fun just to just to know what people have in
• 10:31
  Speaker 1: their minds. And I think one of the common answers
• 10:34
  Speaker 1: is like, tend to the mind is a pretty big number.
• 10:37
  Speaker 1: But yeah, know I thought they were pretty I guess
• 10:38
  Speaker 1: you're at a at a university, so maybe a lot
• 10:41
  Speaker 1: of these folks just think in physics or something. But um,
• 10:45
  Speaker 1: you know, if you ask me, I don't know if
• 10:46
  Speaker 1: I would guess with exact figures or units. Well it's
• 10:50
  Speaker 1: interesting because if you ask me, I don't know what
• 10:53
  Speaker 1: I would say. It's a tricky question. Even what is
• 10:56
  Speaker 1: the meaning of the question, Like what does it mean
• 10:58
  Speaker 1: for the electron to have a side? Is? So it's complicated.
• 11:02
  Speaker 1: So someone interviewed on you on the street and ask
• 11:04
  Speaker 1: you this question, you'd be like, let's sit down for
• 11:06
  Speaker 1: a couple of hours, let me pull out my white board,
• 11:11
  Speaker 1: thank you for asking that question. And you see the
• 11:14
  Speaker 1: panic in their eyes. I've been waiting all my life
• 11:17
  Speaker 1: for perfect strangers. They would feign a phone call and
• 11:20
  Speaker 1: run away quickly. All right, Well, let's get into the
• 11:22
  Speaker 1: trying to answer this question. And I guess the first
• 11:24
  Speaker 1: thing is is that you're telling me is that this
• 11:27
  Speaker 1: is even Um, it's kind of almost a philosophical question.
• 11:30
  Speaker 1: It's like a tricky question in itself to ask what
• 11:32
  Speaker 1: is the size of an electron? Yeah, And you have
• 11:35
  Speaker 1: to be really careful about what you're doing. When you're
• 11:37
  Speaker 1: asking a question that you're used to asking about macroscopic
• 11:41
  Speaker 1: stuff and then applying that to microscopic stuff, you have
• 11:43
  Speaker 1: to be really careful about what you mean and what
• 11:47
  Speaker 1: exactly it is you're trying to learn. You know, like
• 11:49
  Speaker 1: when we think about a ball moving through space, we
• 11:52
  Speaker 1: can talk about its velocity. Cool, But when you want
• 11:55
  Speaker 1: to talk about the velocity of an electron, it's more
• 11:57
  Speaker 1: complicated because it doesn't have like the same kind of
• 12:00
  Speaker 1: half and so it's philosophy changes, and sometimes you can
• 12:03
  Speaker 1: know it, sometimes it's unknown, and so you know, there's
• 12:06
  Speaker 1: an analogy you can make there, but you have to
• 12:08
  Speaker 1: be careful about exactly what you're asking. And the same
• 12:10
  Speaker 1: is true when you ask about the size of something
• 12:13
  Speaker 1: super duper tiny, right, and and especially when you ask
• 12:17
  Speaker 1: about the size of a single thing, right, Like what
• 12:20
  Speaker 1: is it? What does it even mean to ask about
• 12:23
  Speaker 1: the size of anything? Is it like how much space
• 12:26
  Speaker 1: you occupy? Is it like the my longest dimension? Is
• 12:29
  Speaker 1: it the distance between you know, one and one side
• 12:32
  Speaker 1: of me to the other side of me. I think
• 12:34
  Speaker 1: that's it. I think it's the distance between your edges.
• 12:37
  Speaker 1: And so you have a size if you have edges
• 12:40
  Speaker 1: that don't touch, right, if you have if there's a
• 12:42
  Speaker 1: meaning to like there being a left of view and
• 12:44
  Speaker 1: a right of view, and your size is the distance
• 12:46
  Speaker 1: between them. You know, we have a meter stick, how
• 12:50
  Speaker 1: big is it? Well, the left side is one meter
• 12:52
  Speaker 1: from the right side. So that's sort of makes sense, right,
• 12:54
  Speaker 1: And this this all sounds, you know, obvious, but it's
• 12:57
  Speaker 1: going to be important when we get to the quantum
• 12:59
  Speaker 1: realm to be thinking about it in the same same
• 13:01
  Speaker 1: sort of set of ideas. Right, Yeah, I guess you've
• 13:04
  Speaker 1: got to think about what makes it a thing and
• 13:08
  Speaker 1: when is it stopped being a thing? And then then
• 13:10
  Speaker 1: you calculate kind of the distance between the edges of
• 13:13
  Speaker 1: what is and what is not a thing. Yeah, And
• 13:16
  Speaker 1: so you answer the question like what a size mean, Well,
• 13:18
  Speaker 1: it's the distance between the edges and that immediately, but
• 13:20
  Speaker 1: you can see you to the other question, what is
• 13:22
  Speaker 1: the edge, Like what is the edge of a meter
• 13:24
  Speaker 1: stick or the edge of a banana? How do you
• 13:26
  Speaker 1: define where that stops? And that's not so easy. Oh man,
• 13:30
  Speaker 1: you just make me imagine it endless banana and I
• 13:33
  Speaker 1: salivated a little bit. That's a whole universe to you,
• 13:37
  Speaker 1: right there. Man, maybe the whole universe is just one banana.
• 13:40
  Speaker 1: We are all just banana nos in a banana. We
• 13:43
  Speaker 1: should start that in the restaurant. You know, Olive Garden
• 13:45
  Speaker 1: has the endless bowl of salad, endless bread stick. We
• 13:48
  Speaker 1: can we can start selling the endless banana. But anyways,
• 13:51
  Speaker 1: so where is the edge of the banana? Right? You
• 13:53
  Speaker 1: would think, oh, I'm looking at it, I can tell
• 13:55
  Speaker 1: where it stops. And you either you poke it or
• 13:58
  Speaker 1: you're just looking at it. It sort of gives you
• 14:00
  Speaker 1: a sense for like where the edges. It doesn't have
• 14:02
  Speaker 1: a fuzzy edge, like it stops the all the atoms
• 14:06
  Speaker 1: that make up the banana are kind of stuck together,
• 14:08
  Speaker 1: and at some point there aren't any more of the
• 14:10
  Speaker 1: atoms that make up the banana. Yeah, although, if you're
• 14:13
  Speaker 1: zooming close enough right, everything that's not an absolute zero
• 14:17
  Speaker 1: is has a bit of a fuzzy edge, you know,
• 14:19
  Speaker 1: it's like boiling off atoms. Like the reason you can
• 14:21
  Speaker 1: smell banana is that there are volatile molecules on it
• 14:25
  Speaker 1: that are always leaving and so zooming close enough, and
• 14:28
  Speaker 1: there's there's a bit of a fuzzy edge there. But
• 14:30
  Speaker 1: still you can like take a stick and you can
• 14:32
  Speaker 1: poke the banana with your tiny stick and you can ask, like,
• 14:35
  Speaker 1: when does the banana give me resistance? Or is the
• 14:38
  Speaker 1: edge of it is sort of like, you know, where
• 14:40
  Speaker 1: is it push back? Okay, so that that would be
• 14:42
  Speaker 1: the edge of like an object microscopic option you're saying.
• 14:46
  Speaker 1: It has to do with when it no longer interacts
• 14:48
  Speaker 1: with you in the same way as the rest of
• 14:50
  Speaker 1: the banana. Yeah, And there's an important idea there, I think,
• 14:53
  Speaker 1: which is it's not where the stuff of the banana ends,
• 14:56
  Speaker 1: it's where the bananas forces push back. Because you know,
• 15:00
  Speaker 1: the banana itself is mostly made of these we'll talk
• 15:03
  Speaker 1: about in a minute, but time much smaller particles, and
• 15:07
  Speaker 1: the stuff of the banana, the thing that gives it
• 15:08
  Speaker 1: its volume is the forces. Right, If there were no
• 15:11
  Speaker 1: forces between these particles, they will collapse to a much
• 15:14
  Speaker 1: smaller pile. Like you just made a pile of all
• 15:17
  Speaker 1: the atoms inside the banana, it would be almost invisible.
• 15:20
  Speaker 1: Most of that volume comes from them spacing each other.
• 15:23
  Speaker 1: Out by the forces. So it's really the forces, the
• 15:27
  Speaker 1: pushing back that gives the banana it's volume and therefore
• 15:29
  Speaker 1: its size. I see, you wouldn't measure it as between
• 15:32
  Speaker 1: the center of the rightmost atom of the banana to
• 15:35
  Speaker 1: the center of the leftmost atom of the banana. You
• 15:39
  Speaker 1: would be you would extend that a little bit to
• 15:41
  Speaker 1: include like when that atom starts pushing back another adom
• 15:45
  Speaker 1: that tries to poke through the banana. Precisely because if
• 15:48
  Speaker 1: you bring your stick nearby, then the farthest, the most
• 15:51
  Speaker 1: extreme atom and your stick is not going to touch
• 15:54
  Speaker 1: the nucleus of that atom in your banana. They're going
• 15:56
  Speaker 1: to push against each other before they touch. And so
• 15:59
  Speaker 1: that's what I think of sort of the edge of
• 16:01
  Speaker 1: the banana is that force field that sort of protects
• 16:04
  Speaker 1: it from you know, external forces. Okay, so you're saying,
• 16:07
  Speaker 1: as a physicist, you would define the size of something
• 16:09
  Speaker 1: as as the edges of it, and the edges you
• 16:12
  Speaker 1: would define is when they start pushing other things from
• 16:17
  Speaker 1: going through it. Yeah, So really it's more about interactions
• 16:20
  Speaker 1: than it is about matter itself and particle physics, we
• 16:24
  Speaker 1: think a lot about particles and forces, matter and interactions.
• 16:28
  Speaker 1: And I think the size of something really depends more
• 16:31
  Speaker 1: on its interactions then on the stuff that's inside of it.
• 16:34
  Speaker 1: And that makes sense because if you want to know
• 16:36
  Speaker 1: the size of something, you want to know it for
• 16:38
  Speaker 1: a reason usually right, like you want to see if
• 16:40
  Speaker 1: the banana fits inside of a special you know, banana
• 16:43
  Speaker 1: carrying case that you aren't designing. You need to know,
• 16:47
  Speaker 1: you know, not when the set where the centers of
• 16:49
  Speaker 1: the atoms are, but you want to know, you know,
• 16:52
  Speaker 1: if you can fit the banana inside the case. That's
• 16:55
  Speaker 1: exactly it. But it already raises some problems, like what
• 16:58
  Speaker 1: if you had a blob of dark batter the shape
• 17:01
  Speaker 1: of a banana, how big is it? Well, if you
• 17:04
  Speaker 1: can't really interact with it, if you could like put
• 17:07
  Speaker 1: your finger through it, then you know, does that mean
• 17:10
  Speaker 1: that it's a banana shaped and blob of dark batter
• 17:13
  Speaker 1: is smaller? It doesn't have a size maybe even boy. Yeah,
• 17:18
  Speaker 1: so it gets it gets tricky pretty quickly. This thing,
• 17:20
  Speaker 1: which which we thought was simple is actually turns out
• 17:22
  Speaker 1: to be kind of subtle. Yeah, it's feel back the
• 17:24
  Speaker 1: answer to this question and also get into how big
• 17:28
  Speaker 1: an atom is, and then we'll get into how big
• 17:30
  Speaker 1: an electron it is. But first let's take a quick break,
• 17:45
  Speaker 1: all right, Daniel. So it seems like the question of
• 17:47
  Speaker 1: how big something is is kind of fuzzy in itself,
• 17:50
  Speaker 1: and so maybe a good way to kind of tackle
• 17:53
  Speaker 1: it is to start with the next level down from
• 17:56
  Speaker 1: a banana, which is like how big is a is
• 17:59
  Speaker 1: one of the atoms in the in the banana. So
• 18:02
  Speaker 1: remember that we decided that if we're going to talk
• 18:04
  Speaker 1: about the size of the atom, we're not going to
• 18:07
  Speaker 1: ask where is the stuff inside of it? We're gonna
• 18:09
  Speaker 1: ask where does it push back when it's poked? And
• 18:12
  Speaker 1: to figure that out, it's helpful to sort of imagine
• 18:15
  Speaker 1: a whole pile of atoms packed together. Here you have
• 18:18
  Speaker 1: you like imagine the banana is sort of like a crystal.
• 18:21
  Speaker 1: You know, it's like closely packed atoms of the banana.
• 18:24
  Speaker 1: And here it's determined again by the interaction between them,
• 18:27
  Speaker 1: Like how closely packed are they depends on how much
• 18:30
  Speaker 1: they resist being squeezed together. And in this case, for
• 18:33
  Speaker 1: an atom, it's you know, for banana. For other stuff,
• 18:37
  Speaker 1: it's a it's pretty small. It's like you know, fifty
• 18:40
  Speaker 1: to a couple hundred trillions of a meter. Is what
• 18:44
  Speaker 1: how you you would define how big anatom is. Yeah,
• 18:48
  Speaker 1: that's like this the separation between the center of one
• 18:51
  Speaker 1: atom and the center of another atom. Depending on the material,
• 18:55
  Speaker 1: and different things can sort of pack more tightly together
• 18:58
  Speaker 1: than other things. Like hydrogen, you can squeeze it down
• 19:01
  Speaker 1: to like thirty trillions of an atom between protons. But
• 19:06
  Speaker 1: if you're packing lead together, for example, it's almost two
• 19:09
  Speaker 1: d trillions of a meter between sort of the centers
• 19:12
  Speaker 1: of the nuclei. I say, it's it's like if you're
• 19:15
  Speaker 1: trying to measure the size of a bunch of marbles.
• 19:18
  Speaker 1: You would stick him in a container and see how
• 19:20
  Speaker 1: many you can sort of cramp together, and that kind
• 19:22
  Speaker 1: of tells you the size of each marble. Yeah, the
• 19:24
  Speaker 1: distance between the centers of the marbles. There you pack
• 19:27
  Speaker 1: them as closely as you can, and then you measure
• 19:29
  Speaker 1: the distance between the centers of the marbles. Is that
• 19:31
  Speaker 1: actually sort of because you know, when I think of
• 19:33
  Speaker 1: an atom, I think of like, um, you know, like
• 19:35
  Speaker 1: the popular culture drawing of an atom, which is like,
• 19:39
  Speaker 1: you know, little balls in the center and then electrons
• 19:42
  Speaker 1: flying around in orbit. You know, you know, and I
• 19:45
  Speaker 1: know that you know, they're actually like electron clouds. But
• 19:50
  Speaker 1: even the clouds have sort of a size, right, they're
• 19:52
  Speaker 1: drawn as little balloons that stick out of this center.
• 19:55
  Speaker 1: Is the size is the packing size that you're talking about,
• 19:58
  Speaker 1: like how many you can crime in banana, the same
• 20:01
  Speaker 1: as the size of those like electron clouds. Yeah, it's
• 20:05
  Speaker 1: very closely connected. And for a reason, those electrons are
• 20:09
  Speaker 1: the reason that the atoms don't pack more closely together,
• 20:12
  Speaker 1: Like you bring two hydrogen atoms near each other. It's
• 20:15
  Speaker 1: the electron clouds that determine how closely they get together
• 20:18
  Speaker 1: because they form like a covalent bond and make an
• 20:21
  Speaker 1: H two or something like that. And so it's those
• 20:24
  Speaker 1: electrons that determine the interactions between the atoms and determine
• 20:28
  Speaker 1: their spacing. And it's when those two things start overlapping,
• 20:31
  Speaker 1: is when they can no longer really get closer together. So, yeah,
• 20:35
  Speaker 1: the size of the electron cloud is very closely connected
• 20:37
  Speaker 1: to the size of the atom. It really is what
• 20:39
  Speaker 1: defines it. They're always interacting, right, no matter how far
• 20:42
  Speaker 1: apart there are, Like if I had a hydrogen atom
• 20:44
  Speaker 1: here and you had a hydrogen atom and Jupiter. Technically
• 20:48
  Speaker 1: they're sort of repelling each other, right or and or
• 20:50
  Speaker 1: attracting each other or not. They definitely do feel each other.
• 20:53
  Speaker 1: You're write the the extent of the electromagnetic force is infinite,
• 20:57
  Speaker 1: So there are electrons in Alpha Centaur that are pulling
• 21:01
  Speaker 1: on you or pushing on you, or depending on whatever
• 21:03
  Speaker 1: they're doing, technically touching you. Right, you're being touched by
• 21:07
  Speaker 1: an alpha centaur right now. I just got chills down
• 21:11
  Speaker 1: my spine a little bit to the left. Please, yes,
• 21:14
  Speaker 1: thank you. Crash that is that I've had. Yeah, well
• 21:19
  Speaker 1: it's a tricky concept. You're right. If we're going to
• 21:21
  Speaker 1: define size by sort of how you were responding when
• 21:24
  Speaker 1: you get poked, then you're right. You're being constantly poked
• 21:26
  Speaker 1: by everything in the universe. Well, even the stuff like
• 21:30
  Speaker 1: a build B zillion nine years away. Yeah, it is everything.
• 21:34
  Speaker 1: Everything in the universe is feeling you. Although you know
• 21:36
  Speaker 1: there's a time delay there, so the stuff in Alpha
• 21:39
  Speaker 1: Centauri is only feeling. Stuff is feeling where we were
• 21:43
  Speaker 1: a long time ago as a separate issue. So my
• 21:46
  Speaker 1: size depends on time as well. Jeez. But you know,
• 21:51
  Speaker 1: those those things are pretty negligible, and so you can
• 21:53
  Speaker 1: think about like when these things really have an effect
• 21:56
  Speaker 1: if you probe if you shot an electron at um
• 21:59
  Speaker 1: hi'd gin atom, when would it deflect the electron? And
• 22:03
  Speaker 1: if you shot you know, a meter to the right,
• 22:04
  Speaker 1: it wouldn't change the path of the electron really at all.
• 22:07
  Speaker 1: It would, but just it would be very little, It
• 22:09
  Speaker 1: would be very little bit negligible. But then when you
• 22:12
  Speaker 1: you know, hit it right on, then it's going to
• 22:14
  Speaker 1: bounce right back. And and so you can use that
• 22:16
  Speaker 1: to sort of get a sense for what is the
• 22:18
  Speaker 1: meaningful sort of charge radius of a particle. And you're right,
• 22:23
  Speaker 1: it's there's no crisp edge there. So there's a small
• 22:26
  Speaker 1: complication there also because it turns out that the size
• 22:29
  Speaker 1: of something depends on not just what you poke it with,
• 22:33
  Speaker 1: but how hard you poke it. Like, if you poke
• 22:36
  Speaker 1: an atom very gently, it'll seem bigger because you'll notice
• 22:40
  Speaker 1: smaller deflections further away. If you poke it very hard,
• 22:44
  Speaker 1: it will actually seem smaller because you'll overpower the electrons
• 22:48
  Speaker 1: and the outside and only see the nucleus on the inside.
• 22:52
  Speaker 1: There's no point at which it goes to zero though,
• 22:53
  Speaker 1: you're right, right, yeah, So it's it's kind of fuzzy
• 22:56
  Speaker 1: and maybe kind of arbitrary, but you're saying, it's like
• 22:58
  Speaker 1: when when you would actually fee you the force of
• 23:00
  Speaker 1: that electron, that's when maybe you would say, all right,
• 23:03
  Speaker 1: it's sort of impinging on it, which means it's sort
• 23:05
  Speaker 1: of bumping up against it. Mm hmm, And it's not
• 23:08
  Speaker 1: totally arbitrary. Like when you squeeze atoms together, they settle
• 23:11
  Speaker 1: in at a certain distance from each other, so that
• 23:13
  Speaker 1: totally tells you what the equilibrium location is for for
• 23:17
  Speaker 1: the distance between atoms, and that I think is a
• 23:20
  Speaker 1: reasonable way to define the size. But you know, you're right,
• 23:23
  Speaker 1: you have to think about, like what am my meaning
• 23:25
  Speaker 1: by size in this context? In this other context? This
• 23:28
  Speaker 1: basic thing we think about like should be obvious to
• 23:30
  Speaker 1: talk about is it turns out to have a lot
• 23:32
  Speaker 1: of wrinkles to it, all right, So that's kind of
• 23:34
  Speaker 1: how you would define an atom is when it starts
• 23:36
  Speaker 1: to push back another atom, and how much when you
• 23:40
  Speaker 1: crow them inside of a box, you know, what's the
• 23:42
  Speaker 1: natural spacing that they have between them? And it's you're
• 23:45
  Speaker 1: saying sort of related to those electron clouds, which is
• 23:48
  Speaker 1: how kind of how far away the electron goes from
• 23:50
  Speaker 1: the nuclei right, Okay, so that's a that's an atom um.
• 23:56
  Speaker 1: But I guess it gets strict when you talk about
• 23:58
  Speaker 1: individual particles. So let's go down one more level to
• 24:01
  Speaker 1: the proton inside of the nucleus. How big? How how
• 24:04
  Speaker 1: big would you say a proton is? This is a
• 24:06
  Speaker 1: wonderful question. And you know, if you're breaking open the atom,
• 24:10
  Speaker 1: if you're shooting electrons at the atom, it's going to
• 24:12
  Speaker 1: get repelled by the electrons on the outside of it.
• 24:15
  Speaker 1: But if you give them enough energy, then they can
• 24:17
  Speaker 1: sort of penetrate through there, and then you can start
• 24:20
  Speaker 1: to probe the proton inside there, and you can ask, like,
• 24:23
  Speaker 1: how big is this thing? And so we do that exactly.
• 24:26
  Speaker 1: We shoot electrons at protons or hydrogen atoms or or
• 24:30
  Speaker 1: it doesn't really matter if the electron is there anymore,
• 24:32
  Speaker 1: because the probe we're shooting with has so much energy,
• 24:35
  Speaker 1: and we see where does it bounce back and where
• 24:37
  Speaker 1: does it sort of stop bouncing back, and that gives
• 24:40
  Speaker 1: us a sense for how big the proton is, and
• 24:42
  Speaker 1: so we actually have a number for that. But it's
• 24:44
  Speaker 1: tricky because the proton is also made out of things
• 24:47
  Speaker 1: inside of it, sort of like the atom itself. It is.
• 24:50
  Speaker 1: Protons are made of smaller bits that are slashing around
• 24:54
  Speaker 1: inside of it. Those are the corks. But remember that
• 24:56
  Speaker 1: we're trying to define the size of an object, the
• 24:59
  Speaker 1: proton this case, not by where the stuff is inside it,
• 25:03
  Speaker 1: but where it pushes back. And the corks hang out
• 25:06
  Speaker 1: together and push back against the other protons. So if
• 25:10
  Speaker 1: we use our definition, it's the distance between the protons
• 25:13
  Speaker 1: that's going to determine the size of the protons. And
• 25:16
  Speaker 1: that's connected, of course to how the corks are arranged,
• 25:19
  Speaker 1: how they're happy to be inside the proton. The proton
• 25:22
  Speaker 1: is sort of like a cork atom. I See if
• 25:24
  Speaker 1: they were comfortable being a mile apart, you know, like
• 25:27
  Speaker 1: if you try to split it more than a mile
• 25:29
  Speaker 1: or squish the more of them out, they would prefer
• 25:31
  Speaker 1: to be a mile up apart from each other. Now,
• 25:34
  Speaker 1: you would say the size of those two electron at
• 25:36
  Speaker 1: courts is about a mile. So the size of the
• 25:38
  Speaker 1: proton that's that's made up of those corks, yeah, it
• 25:40
  Speaker 1: would be about a mile. But you know, we have
• 25:42
  Speaker 1: nuclei and they have got protons and neutrons inside of them,
• 25:45
  Speaker 1: and each one is like its own little particle. They
• 25:48
  Speaker 1: get squeezed together, but they hang out. They keep their
• 25:50
  Speaker 1: own little particle nature, and so it's just like packing
• 25:53
  Speaker 1: marbles together. You can ask about like the distance between
• 25:56
  Speaker 1: the center of one proton and another, or a proton
• 25:59
  Speaker 1: and a neutron. That's what we think of as the
• 26:01
  Speaker 1: size of the proton. How much can you pack in
• 26:03
  Speaker 1: the quarts that are inside of the proton? Yeah, and
• 26:06
  Speaker 1: that's a really crazy number. That's like one quadrillionth of
• 26:10
  Speaker 1: a meter. It's a really small number. Uh. And that's
• 26:14
  Speaker 1: smaller than a nanometer for sure. It's smaller than a
• 26:17
  Speaker 1: centimeter as well. It's smaller than a mile apparently as well. Um,
• 26:24
  Speaker 1: so that's pretty small. That's pretty small. Yeah, Like, how
• 26:27
  Speaker 1: how big is that in relation to like the size
• 26:29
  Speaker 1: of an atom. Well, an atom is you know, like
• 26:32
  Speaker 1: ten to a hundred ish um trillionth of a meter,
• 26:36
  Speaker 1: So this is one quadrillionth of a meter, So it's
• 26:39
  Speaker 1: like one ten thousands or one hundred thousands the size
• 26:44
  Speaker 1: of an atom. So it's very small compared to the atom.
• 26:47
  Speaker 1: Bare to the electron radius, the proton is super tiny. Okay,
• 26:50
  Speaker 1: wait wait, so um, we have an atom and how
• 26:53
  Speaker 1: about the just the nucleus of the atom. How close
• 26:55
  Speaker 1: together are those protons and neutrons in the nucleus packed together?
• 27:00
  Speaker 1: Those are very tightly packed together. And and again remember
• 27:02
  Speaker 1: that's because that's sort of how the size of the
• 27:05
  Speaker 1: proton is determined. It's like how do those things cluster together?
• 27:08
  Speaker 1: And so the size of like if you have the
• 27:11
  Speaker 1: nucleus of an atom with you know, a hundred protons
• 27:14
  Speaker 1: and neutrons in it, it's not that much bigger than
• 27:17
  Speaker 1: one protonomy. It's like packing above those marbles together. So
• 27:20
  Speaker 1: it's going to be ordered magnitude quadrilliants of a meter.
• 27:24
  Speaker 1: Oh wow, so the new And that's why they say,
• 27:26
  Speaker 1: like the anatom is mostly empty space because you know
• 27:29
  Speaker 1: what you would say is the size of it. Actually
• 27:31
  Speaker 1: the nucleus is like this tiny little bit of it inside. Yeah.
• 27:35
  Speaker 1: And the way that they probe this is two different ways.
• 27:37
  Speaker 1: One is they shoot an electron at proton. But sometimes
• 27:41
  Speaker 1: also they just look at an atom. They just watch
• 27:44
  Speaker 1: an atom sitting there. It's got a proton and an
• 27:47
  Speaker 1: electron and the electron is whizzing all around. And sometimes
• 27:52
  Speaker 1: this is super weird. Sometimes the electron goes inside the proton,
• 27:57
  Speaker 1: like in a quantum mechanical way, or like it actually
• 27:59
  Speaker 1: goes through what's the difference quantum mechanics is reality, dude, um,
• 28:06
  Speaker 1: Like if you were to you know, I mean, like
• 28:07
  Speaker 1: if you were to open the true Dinger's box and
• 28:10
  Speaker 1: you would you would suddenly find it inside of the news. Yeah,
• 28:13
  Speaker 1: the electron in one of its states has non zero
• 28:16
  Speaker 1: probability density to be inside the proton. And when this happens,
• 28:21
  Speaker 1: it's sort of like partially cancels some of the charge
• 28:25
  Speaker 1: pull of this thing because you have the electron now
• 28:27
  Speaker 1: inside the positive atom and then it escapes. But depending
• 28:31
  Speaker 1: on the size of the proton it escaped, this happens
• 28:34
  Speaker 1: more or less often, so you can measure like how
• 28:38
  Speaker 1: often the electron is inside the proton, and that tells
• 28:41
  Speaker 1: you how big the proton is, because the bigger the
• 28:43
  Speaker 1: proton is, the more often this happens. So this is
• 28:46
  Speaker 1: another way we sort of get a sense for how
• 28:48
  Speaker 1: big is the proton. I see, using like probability, like
• 28:53
  Speaker 1: you throw a bunch of darts at it, only sometimes
• 28:56
  Speaker 1: you hit hit the proton. Then that sort of tells
• 28:58
  Speaker 1: you the size. Yeah, exactly, And that's actually the most
• 29:01
  Speaker 1: sensitive test. Basically using the hydrogen's own electron, like pass
• 29:05
  Speaker 1: it through the proton and give you a sense for
• 29:07
  Speaker 1: how big it is. It's crazy. Well, all right, so
• 29:09
  Speaker 1: a proton is about you're seeing one ten thousands of
• 29:13
  Speaker 1: the size of a typical atom. That's pretty small, because
• 29:16
  Speaker 1: a pretty small. So alright, so let's get there. Let's
• 29:20
  Speaker 1: get down now to the last level, which is how
• 29:23
  Speaker 1: big is an electron? And I imagine that's going to
• 29:27
  Speaker 1: be even smaller, but we'll get into that, but first
• 29:30
  Speaker 1: let's take a quick break, all right, Daniel. So now
• 29:45
  Speaker 1: we're down to one of the fundamental particles, the electron,
• 29:48
  Speaker 1: and we're asking the question how big is it? Or
• 29:51
  Speaker 1: how small isn't it? Or how big isn't it? Amount
• 29:57
  Speaker 1: of negatives here, um and so, And I guess what
• 30:01
  Speaker 1: we're talking going to talk about. It sort of applies
• 30:03
  Speaker 1: to quarts as well, right, because we're now talking about
• 30:06
  Speaker 1: single particles, not like clusters of particles. Yeah, and remember
• 30:10
  Speaker 1: that our theory is very hierarchical. We start with matter,
• 30:13
  Speaker 1: and then we go to molecules, from molecules to atoms,
• 30:16
  Speaker 1: from atoms to protons and electrons, and then to quarks
• 30:19
  Speaker 1: and electrons, and we're sort of have shells inside shells
• 30:22
  Speaker 1: inside shells, and so this is sort of our current
• 30:24
  Speaker 1: level of knowledge, and we can ask like, are these
• 30:27
  Speaker 1: particles that we see, um, are they the smallest possible thing?
• 30:30
  Speaker 1: Or is it possible there's something else inside them? So
• 30:33
  Speaker 1: you're right there, quarks and electrons are sort of as
• 30:35
  Speaker 1: far as we've gone, and so in some sense, asking
• 30:38
  Speaker 1: how big are they is asking are they the end?
• 30:41
  Speaker 1: Are they the tiniest, smallest possible thing? Or they possibly
• 30:45
  Speaker 1: made of something smaller? Oh? I see, because if you
• 30:48
  Speaker 1: can split them, that means there's something smaller inside. I
• 30:52
  Speaker 1: guess that's pretty obvious. And that's for you. That sounds
• 30:55
  Speaker 1: deep and it is deep, but it's also kind of obvious,
• 30:57
  Speaker 1: like if you can break it into smaller pieces, then
• 30:59
  Speaker 1: it's there were made of something else. As far as
• 31:02
  Speaker 1: we know, quarks and electrons are not yet made of
• 31:05
  Speaker 1: something smaller. But that doesn't tell you necessarily how big
• 31:08
  Speaker 1: they are. Right, they could be the smallest possible thing
• 31:10
  Speaker 1: and still have a finite size. Right they could be um,
• 31:14
  Speaker 1: the legos of the universe. Lego. Yeah, it could be
• 31:17
  Speaker 1: the smallest lego you can have, but um, that can
• 31:20
  Speaker 1: be smaller, smaller, big, that could be smaller big, And
• 31:22
  Speaker 1: that's fascinating when you learn a number about the universe. Like,
• 31:25
  Speaker 1: let's say we somehow proved that quirks and electrons are
• 31:28
  Speaker 1: not made of anything smaller. They have the smallest lego blocks,
• 31:31
  Speaker 1: and we measured their size, Then we'd we'd know something
• 31:34
  Speaker 1: really deep and basic about the universe, like it's made
• 31:37
  Speaker 1: of legos this size, and you have to wonder, like, well,
• 31:39
  Speaker 1: why that size and not something else? What does that
• 31:42
  Speaker 1: tell you about the universe to know that fundamental fact? Yeah?
• 31:46
  Speaker 1: Did you know there are legos that are smaller than
• 31:48
  Speaker 1: the single unit lego? What? Like you you would think
• 31:52
  Speaker 1: the smallest lego is just like one square with one
• 31:55
  Speaker 1: circle on it, right by saying people have smashed the
• 31:58
  Speaker 1: legos together and make some legos covered the constituent pieces
• 32:02
  Speaker 1: and legos. No, yeah, they make uh this is kind
• 32:05
  Speaker 1: of weird but uh probably not consequential. But um, they
• 32:08
  Speaker 1: make smaller pieces. It makes pieces that fit inside of
• 32:12
  Speaker 1: the whole that some of the single circle lego pieces
• 32:17
  Speaker 1: have inside. Oh my god, you have just violated the
• 32:19
  Speaker 1: standard model of legos. Noble price. Please you've got the
• 32:23
  Speaker 1: prize from that one. Anyways, Um, so, yeah, so let's
• 32:28
  Speaker 1: talk about how big an electron Isn't let's use that
• 32:30
  Speaker 1: as our single particle example. And does it even make
• 32:34
  Speaker 1: sense to talk about the size of a single particle, Daniel,
• 32:37
  Speaker 1: It's hard to talk about the size of a single
• 32:39
  Speaker 1: particle if you haven't measured the stuff inside of it.
• 32:42
  Speaker 1: Because we've talked about the size of atoms and protons
• 32:46
  Speaker 1: based on like how happy this stuff inside of it
• 32:48
  Speaker 1: is to be next near each other, like how closely
• 32:51
  Speaker 1: does it pack? So for a fundamental particle you have
• 32:54
  Speaker 1: to go back to like the poking it and be like, well,
• 32:57
  Speaker 1: if I poked an electron with a stick, where were
• 33:00
  Speaker 1: pushed back? But that's sort of unsatisfying to me. Couldn't
• 33:04
  Speaker 1: can't I just you know, pack a bunch of electrons
• 33:07
  Speaker 1: in a in a glass jar and see, wouldn't that
• 33:10
  Speaker 1: tell me sort of the size of it, Like how
• 33:11
  Speaker 1: comfortable an electron is to another electron or to a proton.
• 33:14
  Speaker 1: Wouldn't that sort of tell you this sort of the size,
• 33:17
  Speaker 1: just like we did with the marbles and the atoms. Yeah,
• 33:20
  Speaker 1: that sounds like a really fun experiment. I want to
• 33:22
  Speaker 1: take like a gas of pure electrons and squeeze it
• 33:25
  Speaker 1: down together and see what happens. The problem is that
• 33:28
  Speaker 1: there's not like a clear answer, like the heart do
• 33:30
  Speaker 1: you squeeze the closer they get together, it's not like
• 33:32
  Speaker 1: an equilibrium like with protons or with atoms, because these
• 33:36
  Speaker 1: are all just negatively charged particles. There's no chill state
• 33:39
  Speaker 1: where they're like, hey, you're there, I'm here. All is good,
• 33:44
  Speaker 1: and so instead you want to like take them and
• 33:46
  Speaker 1: like poke them, like, well, if you poke them with
• 33:48
  Speaker 1: an electron, then they bounce back for sure, But what
• 33:50
  Speaker 1: if you poke them with neutrinos then they don't bounce
• 33:53
  Speaker 1: back at all, Or what if you poke them with
• 33:55
  Speaker 1: dark matter? Then they don't bounce back, And so you're
• 33:57
  Speaker 1: back to this like fuzziness of like you know, if
• 34:01
  Speaker 1: it depends on how it's pushing back, then it depends
• 34:04
  Speaker 1: on what you're poking it with. And then size isn't
• 34:06
  Speaker 1: something that's like inherent to the object. It's about the interaction,
• 34:10
  Speaker 1: which means it depends also on the thing you're interacting
• 34:13
  Speaker 1: it with, which is so frustrating. Oh, I see what
• 34:15
  Speaker 1: you're saying. Like if I had a cloud of electrons,
• 34:18
  Speaker 1: you could maybe talk about where the cloud is, and
• 34:21
  Speaker 1: where the cloud isn't, where the electors are and where
• 34:23
  Speaker 1: there aren't. But with one single electron, it's hard to
• 34:26
  Speaker 1: say where it ends. It's hard to say where it ends,
• 34:29
  Speaker 1: like is there a left side to the electron and
• 34:31
  Speaker 1: the right side to the electron? Are those things even
• 34:33
  Speaker 1: the same thing? Because it depends on what you you're
• 34:37
  Speaker 1: trying to touch it with, right, Like, if you're trying
• 34:39
  Speaker 1: to touch it with another electron, it would maybe repel
• 34:41
  Speaker 1: at a certain distance, But if you try to poke
• 34:44
  Speaker 1: it with a proton, then it would maybe attract at
• 34:46
  Speaker 1: a different distance. Yeah, well not so much electron versus proton,
• 34:50
  Speaker 1: because they both feel the electromagnetism. But what if you
• 34:53
  Speaker 1: used a different force, if you use like the weak
• 34:56
  Speaker 1: nuclear force, or if you used you know, gravity, or
• 34:58
  Speaker 1: if you used electromagnetism, is them than the size that
• 35:01
  Speaker 1: you would get from electron is different. And we're turning
• 35:05
  Speaker 1: to a neutrino. An electron has those eyes. It doesn't like,
• 35:10
  Speaker 1: I don't care, Like the neutrino doesn't care. A neutrino
• 35:13
  Speaker 1: would pass through a cloud of electrons and have a
• 35:15
  Speaker 1: much lower chance of interacting than another electron would, like
• 35:19
  Speaker 1: it wouldn't even know it's there, yeah, or dark matter, right,
• 35:22
  Speaker 1: pokeing a pile of electrons with a stick of dark matter,
• 35:25
  Speaker 1: you're gonna get almost no interactions, or maybe no interactions.
• 35:28
  Speaker 1: We don't even know about dark matter. And this is
• 35:31
  Speaker 1: the problem. It makes sense to define size in terms
• 35:33
  Speaker 1: of interactions, like where is something pushed back, But it
• 35:37
  Speaker 1: also is troublesome because then it depends on what you're
• 35:39
  Speaker 1: pushing on it with. So that's kind of a problem
• 35:41
  Speaker 1: in defining the size of an electron because it depends
• 35:44
  Speaker 1: on what you poke it with. So then we try
• 35:46
  Speaker 1: something else. We say, well, let's think about it like
• 35:48
  Speaker 1: quantum mechanically, Like we've talked about where the electron is,
• 35:52
  Speaker 1: and it's defined by like it's quantum mechanical wave function,
• 35:55
  Speaker 1: and you know you were talking about like those balloon
• 35:57
  Speaker 1: shapes where the electron is. You know, it's the sort
• 36:00
  Speaker 1: of the most you can localize an electron, Like what's
• 36:02
  Speaker 1: the size of that quantum packet? You want to think
• 36:05
  Speaker 1: about it like as a tiny quantum object. That's like
• 36:08
  Speaker 1: another way to try to grapple with it because their
• 36:10
  Speaker 1: probability curves right, Like you know where the cloud is
• 36:12
  Speaker 1: fuzzy tells you that the probability that the electron is
• 36:15
  Speaker 1: there is small, but where the cloud is kind of thick,
• 36:19
  Speaker 1: it tells you that there's a high probability that the
• 36:21
  Speaker 1: electron is there. But that doesn't really give you any
• 36:23
  Speaker 1: insight because that size can be almost anything. It depends
• 36:27
  Speaker 1: on the uncertainty principle. If you know almost nothing about
• 36:31
  Speaker 1: the velocity of the momentum of the electron, then you
• 36:34
  Speaker 1: can know exactly where it is, which means it has
• 36:36
  Speaker 1: like zero that quantum mechanical packets zero with And on
• 36:41
  Speaker 1: the flip side, if you know everything about its velocity,
• 36:45
  Speaker 1: then it's packet is infinitely wide, like exists everywhere in
• 36:49
  Speaker 1: the universe simultaneously have like a universe sized electron. So
• 36:53
  Speaker 1: that's intellectually not that satisfying either. But what if you
• 36:57
  Speaker 1: assume an electron is just standing still, like when you're
• 37:00
  Speaker 1: to measure your kid how all they are and it's
• 37:03
  Speaker 1: impossible because they keep moving. But what if you can
• 37:05
  Speaker 1: get it to stand still? Oh wouldn't what would that happen?
• 37:08
  Speaker 1: Would you be able to then get a pretty accurate size.
• 37:11
  Speaker 1: If you're measuring the velocity of the particle, you're getting
• 37:13
  Speaker 1: it to stand still has no velocity, and you say
• 37:16
  Speaker 1: it has zero velocity, then it has infinite size because
• 37:19
  Speaker 1: you can't know the product. Remember the product of the
• 37:22
  Speaker 1: position and momentum uncertainty has to equal a certain number.
• 37:26
  Speaker 1: And so if you're narrowing down the speed of the
• 37:28
  Speaker 1: electron really really well, that means you don't know anything
• 37:31
  Speaker 1: about where it is. It's an infinite plane. Wave size
• 37:35
  Speaker 1: is only distance, whereas you know in particle physics, distance
• 37:40
  Speaker 1: is kind of intertwined with time as well in velocity.
• 37:43
  Speaker 1: But then on the flip side, if you say I
• 37:44
  Speaker 1: don't care at all about how fast it is, I
• 37:46
  Speaker 1: just want to know where it is, then you can
• 37:49
  Speaker 1: localize it as much as you want. You can make
• 37:51
  Speaker 1: it infinitely narrow. And so that also doesn't give you
• 37:54
  Speaker 1: any sense of like the size of the electron. So
• 37:56
  Speaker 1: strike to we can can use poking or are quantum mathematics.
• 38:01
  Speaker 1: So does that mean that the electron has no size,
• 38:05
  Speaker 1: that it's impossible to define the size of an electron.
• 38:07
  Speaker 1: It kind of does currently. I mean in our theory,
• 38:10
  Speaker 1: the way we actually use it is we assume the
• 38:13
  Speaker 1: electron has no size at all, It has zero volume.
• 38:16
  Speaker 1: That it's just like a point in space. The left
• 38:19
  Speaker 1: is the right, the top is the bottom, the back
• 38:22
  Speaker 1: is the front. There's no extent to it at all.
• 38:25
  Speaker 1: It's sort of mathematically and and because of all the
• 38:27
  Speaker 1: things we just talked about, I guess that that's true. Yeah,
• 38:30
  Speaker 1: you can't measure the size of an electron. It doesn't
• 38:33
  Speaker 1: make any sense to think about it. Yeah, in our theories,
• 38:35
  Speaker 1: we just put zero because we assume that there's nothing there.
• 38:39
  Speaker 1: We have no way to really see the size of
• 38:41
  Speaker 1: the electron. But you know, we do continue to try.
• 38:43
  Speaker 1: We do smash particles at the electron, hoping that we'll
• 38:48
  Speaker 1: see a break open, hoping that we'll see other little
• 38:50
  Speaker 1: particles come out of it. But I guess getting back
• 38:53
  Speaker 1: to the size of the electron itself, um, I mean,
• 38:56
  Speaker 1: it's not like it has no size because it's it's
• 38:58
  Speaker 1: not a mile wide, Like, would you even say that
• 39:01
  Speaker 1: the electron is all electrons are a mile mile wide?
• 39:05
  Speaker 1: I don't know what to say for the size of
• 39:06
  Speaker 1: the electron, you know, And that's why I predicted, I
• 39:08
  Speaker 1: think correctly, that you'd be unsatisfied with Oh my god,
• 39:15
  Speaker 1: it's not really you can't tell the future, can Yeah, well,
• 39:18
  Speaker 1: I can in this case, like I think the way
• 39:21
  Speaker 1: I think about it currently is as a point, But
• 39:23
  Speaker 1: I also know that that makes no sense because like,
• 39:27
  Speaker 1: how do you have something that has mass but has
• 39:30
  Speaker 1: no volume because then has infinite density, which is nonsense,
• 39:33
  Speaker 1: right is it? Electrons have mass, they have mass, and
• 39:36
  Speaker 1: they have charge, Like where does that charge go? Where
• 39:39
  Speaker 1: is it in the electron if it has no volume.
• 39:42
  Speaker 1: We're just used to thinking about stuff as having sizes
• 39:45
  Speaker 1: having volume, So to imagine that the basic building box
• 39:48
  Speaker 1: of the universe themselves are of zero volume is really weird.
• 39:52
  Speaker 1: But I guess maybe you know that that's the theory
• 39:55
  Speaker 1: of it. But practically speaking, I mean, we can talk
• 39:58
  Speaker 1: about what's what's practical to you and me is like
• 40:01
  Speaker 1: electromagnetic forces, right, you know, And it doesn't make sense
• 40:04
  Speaker 1: in terms of neutrinos are dark matter, but kind of
• 40:06
  Speaker 1: what's practical electromagnetic forces? And so couldn't we sort of
• 40:10
  Speaker 1: maybe give a practical size to the electron because of that,
• 40:13
  Speaker 1: like like what's the closest to electrons in one atom?
• 40:17
  Speaker 1: How close can they get to electrons in another atom?
• 40:20
  Speaker 1: Wouldn't that give you a general size? Yeah, and we've
• 40:24
  Speaker 1: done that we like pounded electrons near each other and
• 40:26
  Speaker 1: try to get them as close together as possible, And
• 40:30
  Speaker 1: so far we haven't found a limit, Like, there's no
• 40:33
  Speaker 1: point at which the electrons will not get closer to
• 40:36
  Speaker 1: each other. And so far we've gotten down about ten
• 40:39
  Speaker 1: to the minus twenty meters. And you do that by
• 40:42
  Speaker 1: shooting really high energy electrons at other electrons and try
• 40:47
  Speaker 1: to get them really close together. So that's as far
• 40:49
  Speaker 1: as we could tell. We can't tell the difference between
• 40:51
  Speaker 1: the electrons have no volume, and they have some volume
• 40:55
  Speaker 1: that's smaller than ten to the minus twenty. We can't
• 40:57
  Speaker 1: tell the difference. So far. They look like their point like,
• 41:00
  Speaker 1: but we have some sort of limited resolution there in
• 41:03
  Speaker 1: our ability to probe. So what happens if I the
• 41:05
  Speaker 1: whole universe was just like a proton and an electron,
• 41:08
  Speaker 1: I guess the electron would orbit the proton. That's what
• 41:11
  Speaker 1: hydrogen is. Yeah, The size the hydrogen comes from their interactions. Right,
• 41:15
  Speaker 1: Most of the volume of all the stuff in the
• 41:17
  Speaker 1: universe comes from the interactions, not from any actual volume
• 41:20
  Speaker 1: of the particles that make them up. All right, Well,
• 41:23
  Speaker 1: you're right, this is very unsatisfying. Anim Well, that's satisfying
• 41:29
  Speaker 1: to me that at least I was right about that.
• 41:31
  Speaker 1: But it's a it's a really fun puzzle because I
• 41:33
  Speaker 1: think it's interesting to try to grapple with the quantum
• 41:36
  Speaker 1: realm and try to understand what are the limits of
• 41:39
  Speaker 1: our ability to map these concepts size and mass and
• 41:42
  Speaker 1: charge and velocity down to these tiny particles that, in
• 41:45
  Speaker 1: the end are the reality, are the truth about our universe. Yeah,
• 41:49
  Speaker 1: And I think it's interesting how, you know, you sort
• 41:51
  Speaker 1: of put it that it's all about the interactions, you know,
• 41:54
  Speaker 1: And it's hard to think about an electron not having
• 41:57
  Speaker 1: like a surface or you know, an st where it's
• 42:00
  Speaker 1: no longer an electron, And it all sort of depends
• 42:03
  Speaker 1: on what you're trying to look at it with, you know,
• 42:06
  Speaker 1: Like if you're trying to look at it with neutrinos,
• 42:08
  Speaker 1: then you wouldn't see anything at all. Yeah, But if
• 42:11
  Speaker 1: you looked at it with the electrons, it would feel
• 42:13
  Speaker 1: like a certain size maybe. Yeah. And this is connected
• 42:16
  Speaker 1: to some of the other puzzles we talked about, like
• 42:17
  Speaker 1: does the electron actually spin? We know that it's either
• 42:21
  Speaker 1: a point, in which case it doesn't make sense for
• 42:23
  Speaker 1: it to spin like a point literally cannot spin, or
• 42:26
  Speaker 1: that it's super tiny. But if it's super tiny and
• 42:29
  Speaker 1: it has a surface, then it's spinning so fast that
• 42:32
  Speaker 1: that surface is moving faster than the speed of light.
• 42:35
  Speaker 1: So at some point, like it doesn't even make sense
• 42:38
  Speaker 1: for it to have a non zero size. At some point,
• 42:41
  Speaker 1: nothing makes sense, Daniel, life is meaningless, And that's usually
• 42:44
  Speaker 1: about forty five minutes into every episode. The incredible thing
• 42:50
  Speaker 1: is that we can understand it at all, That we
• 42:52
  Speaker 1: can take these ideas from our everyday experience of like
• 42:56
  Speaker 1: eating bananas and throwing balls around, and then it can
• 42:59
  Speaker 1: give us any side into the microscopic. You know that,
• 43:02
  Speaker 1: because the microscopic is so weird, so alien, it's incredible
• 43:05
  Speaker 1: it works at all that I even have a job.
• 43:08
  Speaker 1: But yeah, but that's the thing it was. We don't
• 43:10
  Speaker 1: understand it, but yet at the same time we're able to,
• 43:13
  Speaker 1: you know, predict it and describe it with math. But
• 43:16
  Speaker 1: that doesn't mean we understand it, right, That's what understanding is.
• 43:19
  Speaker 1: As far as I know, I don't know any deeper
• 43:22
  Speaker 1: level of understanding. When you pass it off to the
• 43:23
  Speaker 1: philosophers and you can ask them, like, you know, what
• 43:26
  Speaker 1: does it mean? Man? But in the end. What we're
• 43:29
  Speaker 1: trying to do is physicists is just sort of describe
• 43:31
  Speaker 1: accurately the world we see around us, build a model
• 43:34
  Speaker 1: in our heads that makes sense, describe all this unknown
• 43:37
  Speaker 1: in terms of the known. That's that's all the understanding
• 43:40
  Speaker 1: we can hope for. Well, I guess what I mean
• 43:42
  Speaker 1: is like at some point we thought the proton was
• 43:44
  Speaker 1: a proton, and we had to math to describe it,
• 43:47
  Speaker 1: and we thought we understood it. But then then it
• 43:49
  Speaker 1: turned out we that we there was more to the
• 43:51
  Speaker 1: proton than we thought, and we didn't actually understand the proton.
• 43:55
  Speaker 1: It was made out of quirks, for example. So I
• 43:58
  Speaker 1: feel like, you know, you have a mathematical di ccription
• 44:00
  Speaker 1: of stuff, but you don't know if you're really understanding
• 44:03
  Speaker 1: it to the fundamental level. And all of these mathematical
• 44:05
  Speaker 1: descriptions they work up to a point. Like your idea
• 44:08
  Speaker 1: thinking about a proton as a fundamental particle as a
• 44:11
  Speaker 1: point particle that mostly works. It works unless you get
• 44:14
  Speaker 1: up to really high energies, energies where you can see
• 44:18
  Speaker 1: inside the proton, because the energies are greater than the
• 44:21
  Speaker 1: bonds that are holding the proton together. And so as
• 44:24
  Speaker 1: we keep pushing to higher and higher energies. We're looking
• 44:27
  Speaker 1: deeper and deeper into the real truth the smallest scales
• 44:30
  Speaker 1: of the universe. And that's what limits how small we
• 44:33
  Speaker 1: can see is the energy with which we probe it.
• 44:35
  Speaker 1: And that's why, like building a bigger super collider would
• 44:39
  Speaker 1: let us maybe see whether the electron had bits inside
• 44:41
  Speaker 1: of it. Yeah, keep funding physics is hey, I'm on message.
• 44:46
  Speaker 1: If nothing else, keep sending those checks. Please, if you
• 44:51
  Speaker 1: have to pick between donating to bananas or fundamental physics,
• 44:55
  Speaker 1: you know where I stand on that. Bananas, right, because
• 44:58
  Speaker 1: bananas are made out of fundamental partners. All right, Well,
• 45:02
  Speaker 1: we hope you enjoyed that, And maybe the next time
• 45:04
  Speaker 1: you take a bite out of a banana or your
• 45:07
  Speaker 1: fruit of choice, maybe think about what it actually means
• 45:10
  Speaker 1: to take a bite. I feel like we've thrown everything
• 45:12
  Speaker 1: into question now, Daniel, Like, what does it even mean
• 45:14
  Speaker 1: to take a bite into When my teeth end and
• 45:17
  Speaker 1: when does the banana begin? I don't know, but every
• 45:19
  Speaker 1: banana you've ever eaten is made out of zero volume particles.
• 45:22
  Speaker 1: Chew on that and think about it until next week.
• 45:25
  Speaker 1: Thanks for joining us, See you next time. Before you
• 45:35
  Speaker 1: still have a question after listening to all these explanations,
• 45:37
  Speaker 1: please drop us a line. We'd love to hear from you.
• 45:40
  Speaker 1: You can find us at Facebook, Twitter, and Instagram at
• 45:44
  Speaker 1: Daniel and Jorge That's one Word, or email us at
• 45:47
  Speaker 1: Feedback at Daniel and Jorge dot com. Thanks for listening,
• 45:51
  Speaker 1: and remember that Daniel and Jorge Explain the Universe is
• 45:53
  Speaker 1: a production of I Heart Radio. For more podcast from
• 45:57
  Speaker 1: My Heart Radio, visit the i heart Radio app, Apple Podcasts,
• 46:01
  Speaker 1: or wherever you listen to your favorite shows. Yeah m