Speaker 1: Do electrons only spin up and down? Or can they
Speaker 1: spin sideways too? Our cells contain quadrillions of vaults, What
Speaker 1: on earth do they do?
Speaker 2: Particles are ripples in quantum fields, So can a field
Speaker 2: exist without them? If you knock on vaults? What does
Speaker 2: it do to the mouse immune system?
Speaker 1: Well, an electron that turns right always turn right? Why
Speaker 1: is dark chocolate better than whites?
Speaker 2: Biology? Physics, immunology, forestry. Uugh, you can never really escape chemistry.
Speaker 1: Whatever questions keep you up at night, Daniel and Kelly's
Speaker 1: answers will make it right.
Speaker 2: Welcome to another Listener Questions episode on Daniel and Kelly's
Speaker 2: Extraordinary Universe.
Speaker 3: Oh.
Speaker 1: I'm Kelly Wienersmith, and I'm a parasitologist, and I am
Speaker 1: learning that there's all kinds of biology topics that I
Speaker 1: just didn't even know existed. And I'm super excited about
Speaker 1: today's episode.
Speaker 4: Hi.
Speaker 2: I'm Daniel. I'm a particle physicist, and I always knew
Speaker 2: there was lots of biology I didn't know anything about.
Speaker 1: I guess it's good to know what you don't know.
Speaker 2: But my question for you today, Kelly, is when was
Speaker 2: the last time one of your kids asked you a
Speaker 2: biology question you didn't know the answer to. Oh, not
Speaker 2: a daily occurrence over there in the Wienersmith household.
Speaker 1: You know, I can't say my kids care about biology
Speaker 1: that much. I don't. My daughter has been reading these
Speaker 1: manga books about like cells biology, and like, we keep
Speaker 1: buying her manga books on physiology and anatomy. And I
Speaker 1: remember a couple years ago and I was looking through
Speaker 1: the biology section at Barnes and Noble, and I saw
Speaker 1: these manga books and I was like, who is the
Speaker 1: audience for this? Who wants to read mangas about cell biology?
Speaker 1: And the answer is ten year old girls. And she
Speaker 1: is absolutely eating it up. But she was explaining to
Speaker 1: me how cells come from other cells and blah blah blah.
Speaker 1: And so I know these days I'm asking her the questions,
Speaker 1: you know, because maybe she knows more about cell biology
Speaker 1: than I do, as we'll learn today.
Speaker 2: That's amazing. I love the idea of educational manca, like
Speaker 2: manca as a way to teach science. What a great idea.
Speaker 2: That's fantastic.
Speaker 1: She is eating it up. What about you? When was
Speaker 1: the last time your kids asked you a physics question
Speaker 1: you didn't know the answer to.
Speaker 2: Oh that happens all the time now because my son
Speaker 2: is taking physics in high school and his girlfriend is
Speaker 2: taking epiphysics, and so they come to me with tough
Speaker 2: physics questions all the time. And I got to sit
Speaker 2: down with a piece of paper and like, Okay, what's
Speaker 2: going on. You got a bullet hitting a block attached
Speaker 2: to a swing, which is the whole thing is tied
Speaker 2: to a squirrel which is running around a bicycle wheel.
Speaker 2: I mean, like, these problems are insane.
Speaker 1: Yikes. Do you usually get the answer?
Speaker 2: I always do figure it out eventually, you know there's
Speaker 2: a method to these problems. I kind of like that actually,
Speaker 2: And when I teach physics here at you See Irvine,
Speaker 2: I'm often doing problems in front of like a five
Speaker 2: hundred person class that I've never seen before because I
Speaker 2: think it's useful for the kids to see me mess
Speaker 2: up and make mistakes, or like say, I'm gonna try
Speaker 2: this with energy. Oh no, that doesn't work, let's back up.
Speaker 2: Or I'll get the wrong answer and then I'll have
Speaker 2: to try to figure out why, because I think it's
Speaker 2: useful for them to see somebody figuring out where things
Speaker 2: went wrong and backing up.
Speaker 1: Yeah, absolutely, And if I don't know the answer, I
Speaker 1: never pretend. I'm always like, what do we need to
Speaker 1: do to figure out what the answer is? We'll start
Speaker 1: with Wikipedia, but then we got to check it, and
Speaker 1: so here's how you search Google, scholar and blah blah blah.
Speaker 2: Exactly, because science is not a list of facts. It's
Speaker 2: a process for learning, right, and you've got to teach
Speaker 2: the process exactly. I totally agree.
Speaker 1: Yeah, Well, our listeners are teaching us a lot with
Speaker 1: their questions lately. Today I'm excited. I got a question
Speaker 1: about an organelle that's founded almost all eu caryotic cells,
Speaker 1: and I was like, what this exists? Then I had
Speaker 1: never heard of it before.
Speaker 2: So you went and you bought the manga on this thing,
Speaker 2: and you learned all about it.
Speaker 1: Right, it would be a pretty short manga, as we're
Speaker 1: gonna discover today because actually there's not a lot that
Speaker 1: we know about this. But you know, maybe manga will
Speaker 1: be my preferred way of learning about things going forward.
Speaker 2: Well, one of my favorite ways to learn about the
Speaker 2: universe is to get asked a question from a listener
Speaker 2: that I don't know the answer to, which makes me
Speaker 2: go and dig into it. In detail, and often when
Speaker 2: people write us questions, which you are all very welcome
Speaker 2: to do to questions at danielan Kelly dot org. If
Speaker 2: I do know the answer, all right, right back. But
Speaker 2: if I don't, I'll delay the answer by saying, hey,
Speaker 2: let's talk about that on the podcast, which gives me
Speaker 2: a week or so to do some research and find
Speaker 2: the answer. So that's what you can be hearing about today,
Speaker 2: some questions that either I didn't know the answer to immediately,
Speaker 2: or questions we thought lots of people might want to
Speaker 2: hear the answer to.
Speaker 1: I feel like you've given our secret away. But that's fine.
Speaker 1: It's true. Whenever we get a question, I'm like, oh,
Speaker 1: we'll do it on the show. That does mean I
Speaker 1: have no idea.
Speaker 2: We're sharing the process to Kelly, right, not just the answers.
Speaker 2: It's all about the process, that's right.
Speaker 1: That's right. We'll be transparent.
Speaker 2: So send us your questions to questions at Daniel and
Speaker 2: Kelly dot org, not Daniel and Kelly dot com. That's
Speaker 2: a very US couple who we hope are having a
Speaker 2: very nice wedding.
Speaker 1: We wish them the best.
Speaker 2: Congratulations Daniel and Kelly. All right, but aswer your questions,
Speaker 2: and on today's episode we have some really fun questions
Speaker 2: about quantum spin, about little bits of the cell, and
Speaker 2: about quantum fields.
Speaker 1: Let's do it, all right, Daniel, First, once for you.
Speaker 2: Our first question is from Bertus, and he's asking a
Speaker 2: question about the spin of particles, which gives me a
Speaker 2: great opportunity to try to disentangle a lot of misconceptions
Speaker 2: about quantum spin. Here's Bert's question.
Speaker 5: Hey, guys, I know when you measure the spin of
Speaker 5: an electron you get up or down. What about if
Speaker 5: the electrons spins perpendicular to the axis of the measurement,
Speaker 5: is it still only up or down? Anything in between? Thanks?
Speaker 1: Oh, so this is great. So you and I have
Speaker 1: had multiple conversations about electron spins and you've mentioned many
Speaker 1: times that the spin is up or down, but it
Speaker 1: never occurred to me, Well, why is it bupper down?
Speaker 1: Why can't it be perpendicular? And I just you know,
Speaker 1: so explain yourself.
Speaker 2: Daniel. That's a great question because it makes an opportunity
Speaker 2: for a nice teaching moment where you can back up
Speaker 2: and try to untangle a misconception about how electron spin works.
Speaker 2: And the thing that birds not understanding. Will dig into
Speaker 2: this in more detail, is that electrons don't like have
Speaker 2: a spin, and then you measure it along some axis.
Speaker 2: There really just are two possibilities for the spin. But
Speaker 2: let's dig into it and first understand, like, what are
Speaker 2: we talking about when we say quantum spin, right, And
Speaker 2: Quantum spin is a strange little property of quantum particles
Speaker 2: that we don't really understand. It's something that we try
Speaker 2: to describe using our intuition for other stuff, like how
Speaker 2: things spin in our world, like you see a ball
Speaker 2: spinning or the Earth is spinning around the sun, and
Speaker 2: so we try to describe this weird new property and
Speaker 2: analogy to something we are familiar with, and we're doing
Speaker 2: this all the time physics, right, Like photons are weird
Speaker 2: and new, so we describe them as kind of like
Speaker 2: a particle and kind of like a wave because they
Speaker 2: have kind of particle eproperties and kind of wavy properties.
Speaker 2: Quantum spin is something weird and new we've never seen before,
Speaker 2: but it does have a lot of similarity to the
Speaker 2: kind of spin we're familiar with, so that's why we
Speaker 2: call it spin. But it really isn't the same thing, all.
Speaker 1: Right, Where to start from there in what ways is
Speaker 1: it similar to what we see?
Speaker 2: Yeah, great question. The thing that makes us call it
Speaker 2: spin is that it's similar to spin in that it
Speaker 2: seems to create magnetic fields. Like when you have a
Speaker 2: charged particle like an electron, and you move it in
Speaker 2: a circle, like you have a loop of wire for example,
Speaker 2: that creates a magnetic field. That's how an electromagnet works.
Speaker 2: How you can run current through something and create a
Speaker 2: magnet And that's like the basis of motors and all
Speaker 2: sorts of stuff. So stuff moving in a circle, charges
Speaker 2: moving in a circle create magnetic fields. Cool. But then
Speaker 2: we discovered that little tiny particles also have their own
Speaker 2: magnetic fields, like electrons. When they're not moving in a circle,
Speaker 2: they have a little magnetic fields. And we notice this
Speaker 2: because if you shoot an electron into a magnetic field,
Speaker 2: it gets deflected either one way or the other way,
Speaker 2: which means it must have a little magnetic field of
Speaker 2: its own, and it can't have like a magnetic charge. Right.
Speaker 2: We talked about on the podcast once how there's no
Speaker 2: like magnetic charge in the universe. All magnetic fields are
Speaker 2: created by electric charges moving in a circle. So people thought, well,
Speaker 2: the electron has an electric charge. Maybe if it's spinning,
Speaker 2: then that's effectively the same as a charge moving in
Speaker 2: a circle, and that would create a magnetic field. Like
Speaker 2: if you took a sphere of metal that had electric
Speaker 2: charges on it and you spun it, that would create
Speaker 2: a magnetic field. So an analogy, people are like, well,
Speaker 2: maybe the electron is spinning. That was the first idea
Speaker 2: to explain the little magnetic field that particles have.
Speaker 1: What are they sitting?
Speaker 2: So then people thought, well, that makes a lot of sense, right,
Speaker 2: and then they sat down to do the calculation. All right,
Speaker 2: if an electric is spinning, well, how fast is its
Speaker 2: surface going, Like what's the speed of the surface of
Speaker 2: the electron? And then they realized, oh, actually that would
Speaker 2: be going much faster than the speed of light. So hmm,
Speaker 2: that doesn't quite work. Plus a lot of people are like,
Speaker 2: electrons are points. Points can't spin. There's nothing to spin
Speaker 2: there if it's like really zero volume, so it can't
Speaker 2: be physically spinning. You shouldn't have the image in your
Speaker 2: mind of like a tiny little beach ball that's actually spinning.
Speaker 2: But it's something very related to spin because it does
Speaker 2: create magnetic fields and it participates in conservation of angular momentum.
Speaker 2: Like we talk about lots of times on the podcast,
Speaker 2: how anglar momentum is conserved in the universe. Like, if
Speaker 2: you have something spinning in space, it will keep spinning
Speaker 2: until something slows it down. The same way if something
Speaker 2: is moving in space, it'll keep going until something slows
Speaker 2: it down. Well, that angular momentum, what you can do
Speaker 2: is you can turn it into particle spin. You can
Speaker 2: like sap the spin of some physical object and turn
Speaker 2: it into particle spin. So particle spin really is a
Speaker 2: kind of angular momentum because the universe allows you to
Speaker 2: slosh like orbital angular momentum into quantum spin angular momentum.
Speaker 2: So it behaves a lot like spin, and it is
Speaker 2: a kind of angular momentum, which is why we feel
Speaker 2: justified like calling it a spin. But it's not like
Speaker 2: a physical spin. It's something fundamentally different.
Speaker 1: You see what I got? Okay, so it's not spinning.
Speaker 1: But we need to explain why. When you send an
Speaker 1: electron at a magnetic field, it goes one way or
Speaker 1: the other way, and there's only two options. And angular
Speaker 1: momentum is if you send something off in a certain direction,
Speaker 1: it just keeps going.
Speaker 2: That's linear momentum. Angler momentum is if you spin something,
Speaker 2: it just keeps spinning.
Speaker 1: Thank you. If you spin something, it just keeps spinning.
Speaker 1: And I'm still not getting the connection between the angular
Speaker 1: momentum spin and why the electron goes one way or
Speaker 1: another way when it hits a magnetic field.
Speaker 2: So the angular momentum comment is just to convince you
Speaker 2: that spin is a kind of angular momentum because the
Speaker 2: universe treats it like that. Like the universe requires that
Speaker 2: angler momentum is not changed. The amount is the same.
Speaker 2: Like you can have stuff banging into each other, you
Speaker 2: can do all sorts of interactions. Whatever anglermentum has to
Speaker 2: be conserved. The amount before some event is the same
Speaker 2: as the amount after some event. Cool. But there are
Speaker 2: different kinds of angular momentum, right, Like you can be
Speaker 2: spinning in place, you can be running in a circle.
Speaker 2: All those things are angle momentum, and it can slash
Speaker 2: back and forth from one kind to the other. And
Speaker 2: this is just to say that the universe includes particle
Speaker 2: quantum spin among the possible kinds of angle momentum. So
Speaker 2: stuff has to be conserved, but it can slash into
Speaker 2: this category as well. So that tells us the universe
Speaker 2: considers quantum spin to be a kind of angular momentum
Speaker 2: when it's doing its accounting, and it requires anglermentum to
Speaker 2: be the same before and after. Quantum spin is one
Speaker 2: of the possibilities. So it's like when you put a
Speaker 2: thousand dollars in your bank account, you expect it to
Speaker 2: still be there when you come back. Maybe it's moved
Speaker 2: into checkings, maybe it's moved into savings. Whatever, it's still
Speaker 2: one thousand dollars. This is saying the universe treats this
Speaker 2: as the same kind of accounting as it does other
Speaker 2: things which are legitimate physical spin, like orbits and running
Speaker 2: in a circle and whatever. The universe treats all these
Speaker 2: accounts as if it's just dotted lines that are the
Speaker 2: humans draw between stuff. So that's what makes it say
Speaker 2: it really is a kind of spin. Now the second bit,
Speaker 2: it can only go one way or the other. That's
Speaker 2: the quantum piece, And that's what Burtis is asking about,
Speaker 2: because when you send electrons into a magnetic field, you
Speaker 2: don't get a whole spread of outcomes. It's not like, well,
Speaker 2: if the spin is all the way to the left,
Speaker 2: it goes one way, and if the spin is all
Speaker 2: the way to the right, it goes the other way.
Speaker 2: But you can also get answers in the middle. What
Speaker 2: they saw when they did these experiments in the nineteen
Speaker 2: twenties was very clear. They either go left or they
Speaker 2: go right. There's no electrons that go through the middle
Speaker 2: and nothing in between. That's what's quantum about the spin.
Speaker 2: It's either up or it's down. And that's what Birth'
Speaker 2: question is, like, well, what happens if the spin is perpendicular,
Speaker 2: which way does it get measured? And that's sort of
Speaker 2: what Birth's question is.
Speaker 1: So you've got an electron. You look at the electron
Speaker 1: before you send it to the magnetic FID. Can you
Speaker 1: predict if it goes left or right or no? Because
Speaker 1: you've observed the electron and something collapses and physics is impossible, you.
Speaker 2: Can predict if you measure it spin. If you measure
Speaker 2: it spin and the spin is to the left, then
Speaker 2: you know it's spin is going to be to the left.
Speaker 2: When it goes to the magnetic field, it's going to
Speaker 2: go to the left. So yes, you can measure the
Speaker 2: electron spin beforehand and know it. You can also leave
Speaker 2: it uncertain and maybe it's left or maybe it's right,
Speaker 2: and then you'll know when you send it into the
Speaker 2: magnetic field. That's when the universe decides, Oh, this one's
Speaker 2: going to be left or this one's going to be right.
Speaker 2: So yes, you can observe it.
Speaker 1: But if it's not spinning, how do you know if
Speaker 1: it's up or down? If you don't send it into
Speaker 1: the magnetic field and then see what it does.
Speaker 2: Sending it into a magnetic field is the only way, right.
Speaker 2: Oh yeah, So if you have like two of these
Speaker 2: in a row right, and say, for example, you send
Speaker 2: it through one who goes left, you're like, okay, now
Speaker 2: I know it's left. You send it through another one
Speaker 2: of those same devices, it's still going to go left
Speaker 2: because you're measured it left, it is left.
Speaker 1: Got it all right? And angular momentum is concerned exactly,
Speaker 1: always go exactly. Okay, got it? I'm with you. What's
Speaker 1: the answer that.
Speaker 2: The answer is that you shouldn't think about the electron
Speaker 2: is having some true spin direction the way the Earth does.
Speaker 2: Like the Earth has an axis around which it's spinning right,
Speaker 2: call it the north pole. And you might ask, look, well,
Speaker 2: I'm going to measure it spin along this axis. Is
Speaker 2: it more up or is it more down? And that's
Speaker 2: going to give you my answer. The electron doesn't have
Speaker 2: some true spin angle and you're just measuring the projection
Speaker 2: of that along some axis. There's only two possibilities for it.
Speaker 2: It's either up or it's down. That's what it means
Speaker 2: to be quantum, not that there is some true continuous
Speaker 2: set of values that are hidden from you and you're
Speaker 2: just getting a discrete answer. It's not like electrical engineering
Speaker 2: where you have like analog waveforms that you're then digitizing
Speaker 2: into zeros and ones. It is either zero or it
Speaker 2: is one, and the in between state is having a
Speaker 2: probability of being zero and a probability of being one.
Speaker 2: It's not like there some arrow there that you're projecting
Speaker 2: along the axis. True spin state can't be perpendicular. It's
Speaker 2: just not an option. It's either up or it's down,
Speaker 2: or it's a mixture of those two possibilities.
Speaker 1: Not a lot of options front.
Speaker 2: And you might think, Okay, well, I'm just gonna measure
Speaker 2: the spin state along the X axis, and then i'll
Speaker 2: measure along the Y axis. Then I'll measure along the
Speaker 2: Z axis and then I'll sort of know it in
Speaker 2: three D. The amazing thing is the universe doesn't let
Speaker 2: you do that because you can't know the spin direction
Speaker 2: in two axis simultaneously, the same way you can't like
Speaker 2: no position and momentum simultaneously. The universe prevents you from
Speaker 2: knowing that it's like undetermined thanks to the uncertainty principle.
Speaker 2: If you measure the spin along X, you get either
Speaker 2: up or down, right, left or right. If you then
Speaker 2: measured along Y, it scrambles it in X. So let's
Speaker 2: go back to that experiment we talk about. Say you
Speaker 2: send it through the magnetic field and it goes left.
Speaker 2: Now you have another set of those magnetic field devices,
Speaker 2: but you've rotated in ninety degrees, so it's like selecting
Speaker 2: along a different axis, and now it goes like up
Speaker 2: or something. So it's gone left and then it's gone up.
Speaker 2: Now send it through the original device again, and you
Speaker 2: might think, well, I know it's left right. It was
Speaker 2: left before. It's got to be left again. But no
Speaker 2: measuring it along the up down axis has scrambled the
Speaker 2: left right information, and so now it might go right.
Speaker 1: So that doesn't sound very conserved, Daniel, what happens.
Speaker 2: What happens is that the interaction has scrambled the angler momentum,
Speaker 2: so the machine itself has absorbed some of that angler momentum.
Speaker 1: Physics is trippy.
Speaker 2: Physics is trippy. So the bottom line, Bird is that
Speaker 2: you can't think about the spin of this particle number one.
Speaker 2: It's a physical spin. It's a quantum weird thing which
Speaker 2: is similar to spin, but not really exactly the same.
Speaker 2: And you shouldn't think of it as being like some
Speaker 2: true vector that you're then projecting into X or y
Speaker 2: and that has some like true valley that could be perpendicular.
Speaker 2: It can never be perpendicular. It's either up or down
Speaker 2: or some mixture of those two. There is nothing in between.
Speaker 1: All right, Wow, a rare instance where physics has a
Speaker 1: clear answer. Ooh oo oooh slice. But let's see if
Speaker 1: it's it's intelligible, all.
Speaker 2: Right, brut tell us if we clarify that or just
Speaker 2: confused you.
Speaker 5: Hey guys, as always, thanks for the great explanation. Love
Speaker 5: listening to your podcast.
Speaker 1: All right, So onto something completely different. We got this
Speaker 1: amazing question from Ryan about an organelle that I didn't
Speaker 1: even know existed. So let's hear Ryan's question.
Speaker 3: Hi Kelly, Hi Daniel, Thank you both so much for
Speaker 3: your wonderful show. I've just become aware of the existence
Speaker 3: of this cell organelle called the vault. I'm so surprised
Speaker 3: and fascinated that a structure that's apparently so common in
Speaker 3: cell biology should be so mysterious to us still, and
Speaker 3: that it was discovered so recently. Also, what a name
Speaker 3: for something so mysteriou is the vault? It'd be great
Speaker 3: if you guys could bring us up to speed on
Speaker 3: the state of the science and the understanding in relation
Speaker 3: to this crazy little thing. What do we think therefore,
Speaker 3: how did they get there? And how did they avoid
Speaker 3: our detection for so long?
Speaker 1: Thank you so much, Daniel. Have you ever heard of
Speaker 1: the vaults?
Speaker 2: I've never heard of the vault. I've never heard of
Speaker 2: a part of the cell that started with the before,
Speaker 2: like the mitochondria. I guess the nucleus. It seems especially important.
Speaker 2: But I'm also just not one hundred percent clear on
Speaker 2: what an organelle is. Is it a miniature piece of
Speaker 2: the cell in analogy to like how my liver is
Speaker 2: an organ in my body. It's like a specialized component
Speaker 2: of my body is an organelle, like a specialized part
Speaker 2: of the cell that does one particular job.
Speaker 1: Yes, yeah, that's a great definition.
Speaker 2: So why they call it organelle? Is it like organito
Speaker 2: or something like that?
Speaker 1: I think yes, I think it is like organito.
Speaker 2: I think organito is cuter.
Speaker 1: Yeah, I no, I agree. I don't know who we
Speaker 1: write to submit these recommendations to, but let's get on
Speaker 1: that all right.
Speaker 2: So tell us about the organito called the cell? What
Speaker 2: does it do? Why does nobody know anything about it?
Speaker 2: How come I've never heard of it before?
Speaker 1: It's all amazing, Okay, So you find it in u
Speaker 1: caryotic cells. So these are cells specifically that have nuclei
Speaker 1: that have a membrane and like so inside the DNA
Speaker 1: is sort of stored inside these nuclei. So like when
Speaker 1: we talk about prokaryotic cells, we're talking about bacteria and
Speaker 1: Archaea and just about like everything else is eukaryots. So
Speaker 1: it's like everywhere, and it's bigger than a ribosome. So
Speaker 1: like I think most of us learned about ribosomes in biology.
Speaker 2: I don't know if I should be impressed by that,
Speaker 2: because I don't know how big a ribosome is.
Speaker 1: I don't really have a good like gut intuition for
Speaker 1: how big a ribosome is, but I do know that
Speaker 1: in cell biology or in biology, I was taught the
Speaker 1: thing that looks like sort of like a big thick squiggle,
Speaker 1: you write ribosome next to that. The point that I'm
Speaker 1: trying to make is that it is bigger than a
Speaker 1: thing that we have known has existed for a really
Speaker 1: long time, and so it's surprising that we didn't also
Speaker 1: know that this existed for a really long time.
Speaker 2: So not really crazy tiny. It's not like it's hiding
Speaker 2: because it's super small. It's like kind of a big component.
Speaker 2: It's like not understanding what a toaster is in your kitchen.
Speaker 1: Yeah, exactly, that's right. It's big enough to see and
Speaker 1: there are lots of them. So there's like ten thousand
Speaker 1: in each cell. Whoa, yeah, so in our body you
Speaker 1: might have as many as one hundred and sixty quadrillion
Speaker 1: vaults in you.
Speaker 2: What that blows my mind.
Speaker 1: I know they're huge, and so what they are. So
Speaker 1: it looks like if you've ever been in a cathedral
Speaker 1: and you've looked up at the ceiling. The folks who
Speaker 1: discovered this organelle felt like the ceilings of a cathedral,
Speaker 1: which are sometimes I think called vaults, kind of looked
Speaker 1: like this organelle, but it would be like two of
Speaker 1: them put together. So to me, it kind of looks
Speaker 1: more like a barrel and the inside is empty and
Speaker 1: it's mostly made out of three proteins, and then it
Speaker 1: has a little bit of ribonucleic acid in it, so
Speaker 1: a little bit of RNA.
Speaker 2: So hold on, I have to totally adjust my mental
Speaker 2: picture here because when you said the vault, I was
Speaker 2: thinking of a safe that there's some like deep secret
Speaker 2: about life in the universe stored inside ourselves, and today
Speaker 2: we're gonna crack al Capone's vault or something like that.
Speaker 2: Now you're telling me I have to replace it with
Speaker 2: like the idea like a little capsule. It's like a
Speaker 2: little thing that holds stuff. So it was a little
Speaker 2: bit like a container.
Speaker 1: Yeah, and it's empty in the inside. So yes, you're
Speaker 1: your thought. I mean, we are not going to crack
Speaker 1: al capone safe today. That is for a bit of
Speaker 1: a spoiler, we have not really cracked the vault yet.
Speaker 2: Let's get Heraldo on the show and maybe you'll help
Speaker 2: us out.
Speaker 1: Oh yeah, yeah, let's definitely recommend Heroldo's shows to our listeners.
Speaker 1: All right, So you've got this like compartment. You have
Speaker 1: loads of them, and it was discovered for the first
Speaker 1: time in nineteen eighty six, Wow, by Nancy Kadersha and
Speaker 1: Leonard Rome. And the reason they discovered it was an accident.
Speaker 1: So they were looking at vesicles, which are these little
Speaker 1: things that you find in cells. They're another organito that
Speaker 1: sort of moves things around. And while they were trying
Speaker 1: to like get a bunch of vesicles together for their experiments,
Speaker 1: they looked in their sample and they were like, oh,
Speaker 1: there's all of this like contamination, and it was a
Speaker 1: little bit hard to see, but they were like, okay, well,
Speaker 1: let's try to get the contamination out. And then they
Speaker 1: realized like, oh wait, this isn't contamination, this is something
Speaker 1: else that was in the cell. And they realize the
Speaker 1: reason it had been missed for so long is because
Speaker 1: when you're trying to look at the inside of the cell,
Speaker 1: you often put stains inside of a cell that binds
Speaker 1: the RNA, and the vault is only about four percent RNA,
Speaker 1: so it's staining, but it's staining in a very like
Speaker 1: light and easy to miss way. So a bunch of
Speaker 1: people had been looking at the stuff that stained with
Speaker 1: the RNA, like the vesicles and missing the vaults. So
Speaker 1: this group just got lucky that they happened to like
Speaker 1: get the vaults with the rest of their samples of vesicles,
Speaker 1: and that they noticed this like junk in the background.
Speaker 2: And they weren't using staining, so they didn't miss the vaults.
Speaker 1: They were using staining, but they looked at the sample
Speaker 1: close enough, and instead of ignoring what looked like junk
Speaker 1: in the back background, they were like, wait, that junk
Speaker 1: all has like the same shape and there's a lot
Speaker 1: of it. What is that? And then they were like,
Speaker 1: holy crow, a whole new organelle.
Speaker 2: Wow. I think that says something really powerful about science,
Speaker 2: that you know, often what we do is imperfect, and
Speaker 2: we tried like the only possible thing first because we
Speaker 2: can get some information, but then we sometimes forget that
Speaker 2: that's limited or that it's made some assumptions, and we
Speaker 2: don't always go back and like re explore that understand
Speaker 2: like what are we missing if this is the only
Speaker 2: thing we're doing. You know, it's sort of like the
Speaker 2: example of like, well this works in mice yeah, yeah,
Speaker 2: we can do it in mice, doesn't mean that it's
Speaker 2: going to work anywhere else. And we've learned something universal, Right,
Speaker 2: it's fascinating to then crack these doors open. What was
Speaker 2: that moment like for them? Do you think that they realized, like, wow,
Speaker 2: all of this is actually something fascinating.
Speaker 1: It sounds like they were pretty excited by that moment,
Speaker 1: And yeah, I agree, like what we know about biology
Speaker 1: is limited by the tools we have, and sometimes we
Speaker 1: don't even realize that our tools are limiting what we
Speaker 1: know about But my sense is they were pretty excited,
Speaker 1: and they actually had the lab members they all sort
Speaker 1: of like pitch different names for what to call it,
Speaker 1: and they had a little bit of a contest.
Speaker 2: Do you have the alternatives? That would be amazing.
Speaker 1: I wasn't able to find the alternatives.
Speaker 2: Organito face wasn't up there.
Speaker 1: Oh man, society has been robbed of that opportunity. But
Speaker 1: the vault is a pretty sweet name.
Speaker 2: I think it's very cool, Yes, very dramatic.
Speaker 1: Yeah, And so, as I mentioned, it's found in eukaryotic cells,
Speaker 1: and it's found in like very similar ways in all
Speaker 1: of these eukaryotic cells. So often when you find something
Speaker 1: in biology, and you find it in lots of places,
Speaker 1: and in all of those places it looks exactly the same.
Speaker 1: That suggests that evolution is doing something to stabilize it. Like,
Speaker 1: this has a really important function. We're not going to
Speaker 1: tinker with it because tinkering with it can break it.
Speaker 1: You need this, it can't.
Speaker 2: Be broken, and it's common across eu caryots. Means it
Speaker 2: provides something really basic. Right. This isn't like, hey, this
Speaker 2: makes the wings on a hummingbird really really light. This
Speaker 2: is like essential to some foundational part of life. Right.
Speaker 1: That was the initial hypothesis, which to me seems totally reasonable.
Speaker 1: And there are some places where it's been lost. So
Speaker 1: for example, fruit flies, which are like, you know, a
Speaker 1: model that's studied in biology all over the place, and yeast,
Speaker 1: which is also studied a lot, they don't have vaults
Speaker 1: for reasons we don't understand. So it's got a bit
Speaker 1: of a spotty distribution, but most organisms do have it. Okay,
Speaker 1: so what do we think done?
Speaker 2: Yeah, tell us Colleen, crack the vault open for us.
Speaker 1: Yeah. So the answer is, actually, we don't know. So
Speaker 1: biology biology, I know, it depends. So one hypothesis is
Speaker 1: that it's important for transporting toxic stuff that's in a
Speaker 1: cell out of a cell. And the reason we think
Speaker 1: that is because there are people who have tumors and
Speaker 1: when they've gotten their chemotherapy or there are various drug treatments,
Speaker 1: it looks like the vault isn't involved in making those
Speaker 1: drugs work less well by shuttling it out of the
Speaker 1: tumor cells. And so the thought was that this vault
Speaker 1: is going around and anytime there's something bad in the cell,
Speaker 1: and chemotherapeutic drugs can be pretty toxic, you know, they're
Speaker 1: trying to kill cancer cells, the vault would like put
Speaker 1: it in the middle of the vault, shuttle it to
Speaker 1: the outside of the cell, and then dump it back
Speaker 1: outside of the cell. But you know, chemotherapeutic drugs were
Speaker 1: not like a common part of our evolutionary history and
Speaker 1: they exist not in the rest of the animal kingdom
Speaker 1: for the most part. So the idea is that maybe
Speaker 1: anything toxic they move. There's some thought that they're important
Speaker 1: for like the immune response, like maybe they could encapsulate
Speaker 1: a virus and shuttle that outside of the cell. There
Speaker 1: was an observation that the vault connects to the inside
Speaker 1: structure of the cell. So the cell has like essentially
Speaker 1: what you'd think of as like a lumber structure that
Speaker 1: sort of like holds it up. It's got scaffolding, and
Speaker 1: it was attached to it, and so there was some
Speaker 1: idea that maybe it attaches to that and moves around
Speaker 1: the cell and transports things like take it from the
Speaker 1: nucleus and bring it to another organelle orgin eto. But
Speaker 1: at the end of the day, we don't actually have
Speaker 1: a good answer. And so one of the guys who
Speaker 1: helped to discover it, whose last name is Rome, he
Speaker 1: joked that actually the purpose of the vault is to
Speaker 1: fund his lab because he had spent fifteen years trying
Speaker 1: to figure out a function. And they have some like
Speaker 1: tantalizing associations, but at the end of the day, no
Speaker 1: one has been able to pin down this is what
Speaker 1: the vault does, and we're sure and this is his
Speaker 1: main function.
Speaker 2: Well, help me understand why it's so hard to figure out.
Speaker 2: I mean, I understand, like when we're talking about quantum particles,
Speaker 2: one of the challenges is that you can never really
Speaker 2: zoom in and see them and watch them. But here
Speaker 2: we're talking about like kind of big biological things that
Speaker 2: you could, in principle see under a microscope. Why can't
Speaker 2: we just like watch as sell in action and say, like, oh,
Speaker 2: I see what the vault is doing. Like imagine you
Speaker 2: come into a city as an alien, You're like, what
Speaker 2: are all these male people doing. Oh, they're going from
Speaker 2: house to house delivering letters. You'd figure it out by
Speaker 2: watching what they're doing. Is that not possible for some
Speaker 2: reason or oversimplifying it? Why can't we just watch the
Speaker 2: vaults and figure it out?
Speaker 1: Yeah, So here's my best guess as someone who doesn't
Speaker 1: do cell biology. So a lot of times what's important
Speaker 1: is important in the system that it's found. And so
Speaker 1: for example, if you're studying this in a mouse, you
Speaker 1: can't watch what's happening inside of a mouse cell while
Speaker 1: it's still inside of the mouse. And so if you
Speaker 1: really want to understand what it's doing. Often if you
Speaker 1: just take a mouse sell out, for example, and you
Speaker 1: put it in a dish, then it can't do a
Speaker 1: lot of the stuff that it usually does, Like if
Speaker 1: it's involved in the immune system, it's you know, can't
Speaker 1: signal with the other cells.
Speaker 2: And then native question because to image a mouse sell
Speaker 2: you have to remove it from the mouse. You can't
Speaker 2: like put a whole mouse under a microscope and say, like,
Speaker 2: I'm going to look at this cell on the surface
Speaker 2: and see what its vaults are doing.
Speaker 1: That's right. Yeah, So to stain and see what's happening
Speaker 1: inside of a cell at that level, I think we
Speaker 1: still need to put it under very specialized microscopes and cameras,
Speaker 1: and it can't be inside of the mouse while it's happening.
Speaker 2: Well, there's your answer. We need to develop technology for
Speaker 2: a whole mouse microscope.
Speaker 1: There you go, there, you get right, and then if
Speaker 1: we could see that, then maybe we'd have all of
Speaker 1: our answers.
Speaker 2: All right, So you've got to take the mouse sell
Speaker 2: out do specialized stuff. Then that changes what the cell
Speaker 2: is doing, which makes a lot of sense. So we
Speaker 2: don't necessarily get a clear picture of the cell in
Speaker 2: its actual action.
Speaker 1: And I don't actually have enough experience with imaging to
Speaker 1: know how easy it is to stain things inside of
Speaker 1: a cell that are this small and then still watch
Speaker 1: what's happening inside of cells like in live time. It's
Speaker 1: possible we might have to indirectly do things like somehow
Speaker 1: make a cell or figure out a cell line that
Speaker 1: makes more vaults than another, and then expose those two
Speaker 1: different cell lines to chemotherapeutic drugs, and then you can
Speaker 1: say like, Okay, this cell line split the chemo therapeutic
Speaker 1: drugs out more than the other cell line, and this
Speaker 1: one had more vaults. And so you know, you're indirectly
Speaker 1: trying to figure out what's happening based on the responses
Speaker 1: without being able to actually like be in there watching
Speaker 1: everything happening in lifetime.
Speaker 2: Wow, So out, what are people doing right now to
Speaker 2: study it? What is the room lab writing grants about
Speaker 2: right now?
Speaker 1: According to an article that I read that came out
Speaker 1: through the Royal Society, the answer is pretty much funding
Speaker 1: agencies have gotten tired of paying for trying to figure
Speaker 1: out what the vault does when they have no answer.
Speaker 1: And so doctor Rome, I think, is emeritus now, so
Speaker 1: he's retiring and trying to get other people excited about it.
Speaker 1: I'm going to step back really quick and mention some
Speaker 1: mouse works. So you wanted to know, like, how do
Speaker 1: you study this? So one of the ways that we've
Speaker 1: studied it is we knock out the information needed to
Speaker 1: make the proteins in the vaults, and then you look
Speaker 1: to see what happens to the mice that are missing
Speaker 1: these proteins. And this is what I think was the
Speaker 1: most interesting when I was doing the research. So when
Speaker 1: you like knock out one of the proteins, maybe tumors
Speaker 1: grow a little bit more in those mice if they
Speaker 1: have cancers.
Speaker 2: And just to be clear, knocking out means removing the
Speaker 2: genetic code so that the cell doesn't know how to
Speaker 2: make the vaults anymore.
Speaker 1: Exactly or make a component. So we mentioned at the
Speaker 1: beginning that the als are made out of three main proteins,
Speaker 1: So if you're knocking out the code to make those proteins,
Speaker 1: then maybe you'd get a vault that is like you know,
Speaker 1: it's like a basket that's missing some of the weaving
Speaker 1: because one of those proteins is missing. So it was
Speaker 1: a little bit associated with tumor cell size. There was
Speaker 1: another one that was a little bit associated with immune
Speaker 1: system functioning, and when you knocked it all out, maybe
Speaker 1: the mice grew a little bit more slowly. But like
Speaker 1: you know, the initial prediction was that this must be
Speaker 1: crucial for life because you see it everywhere and it's
Speaker 1: so conserved by evolution, but you knock it out and
Speaker 1: the animals seem okay, And so what is this doing?
Speaker 1: And so I don't know what the answer is. No
Speaker 1: one does. But you know, I wonder, is there's something
Speaker 1: that we haven't done to these mice in the lab yet, Like,
Speaker 1: you know, if you expose them to radiation, do they
Speaker 1: all just like die immediately? Is there something that we
Speaker 1: haven't tested yet? And under those conditions vaults are crucial.
Speaker 1: But at the moment you can knock this stuff out
Speaker 1: and the animals seem to do okay without them.
Speaker 2: Well, here's the sort of basic evolutionary biology questionesting that
Speaker 2: it's conserved, which you must mean it has an important function.
Speaker 2: I think the implicit argument is out there in the
Speaker 2: wild is probably getting knocked out cosmic rays or random mutations.
Speaker 2: And if it didn't serve a function, then those knockout
Speaker 2: animals would thrive. But would they necessarily be selected for? Like,
Speaker 2: is there an advantage to not making the vault? If
Speaker 2: there's no cost to making the vault, can't you just
Speaker 2: sort of stick around and hang out as part of
Speaker 2: our genetic code?
Speaker 1: Yeah, okay, so let me see if I understand the question. So, first,
Speaker 1: I'll note that if you make one hundred and sixty
Speaker 1: quadrillion of these, there's probably some cost to making that
Speaker 1: many of them, and there's something we're not understanding. So
Speaker 1: maybe something that I'm about to say is wrong and
Speaker 1: we just don't realize it. But if you make that many,
Speaker 1: it seems like there's got to be a cost, and
Speaker 1: if they weren't producing some function that was pretty regularly
Speaker 1: needed by organisms, you would expect them to not keep
Speaker 1: paying that cost, right, Okay, So for radiation to knock
Speaker 1: the vault out, it would have to mess up cells
Speaker 1: that are inside of the new gleist that code for
Speaker 1: the proteins in the vault. Like, I don't know how
Speaker 1: often that's happening, so I'm not quite sure I'm a
Speaker 1: understanding the radiation part of your question.
Speaker 2: I was just wondering if nature has done these experiments
Speaker 2: essentially removing the vault from animals through random mutation or
Speaker 2: radiation or whatever, and then competed those no vault organisms
Speaker 2: against the vault organisms, And I was wondering why, if
Speaker 2: there's no benefit to the vault, the no vault organisms,
Speaker 2: which must exist also in nature, hadn't outcompeted everybody else.
Speaker 1: Yeah, that's a great question, and that might be where
Speaker 1: the vaultless fruit flies and the vaultless yeast came from.
Speaker 1: And I think there's plants without vaults. So I think
Speaker 1: an important question for biologists to ask is do we
Speaker 1: actually need these All these organisms can live without them,
Speaker 1: and why are the rest of us holding onto them
Speaker 1: if they seem so inconsequential. Why are we making one
Speaker 1: hundred and sixty quadrillion of these things if we don't
Speaker 1: really need them? And I don't think we know.
Speaker 2: And maybe that's why I'm so tired of the evenings,
Speaker 2: right because I spent my day building all these vaults.
Speaker 1: That's right, that's right. Wait, give it a break, body.
Speaker 1: We don't need these things, and they're not even good
Speaker 1: when you have cancer. Sometimes you asked what are people
Speaker 1: working on now? I did come across a variety of
Speaker 1: papers where people are trying to figure out how to
Speaker 1: take advantage of the fact that you have this organelle
Speaker 1: that's empty in the inside, that is maybe able to
Speaker 1: move around the cell and deliver things from place to place.
Speaker 1: Could you use it as a way to deliver drugs
Speaker 1: if you could sort of hijack its use. So folks
Speaker 1: are now trying to figure out if vaults can be
Speaker 1: used to our benefit in some way, even though we
Speaker 1: don't know what their initial purpose is supposed to be.
Speaker 2: I'm imagining like those little capsules that you can send
Speaker 2: through the hydraulic tubes or I guess the air pressure
Speaker 2: tubes at banks and stuff like that. That'd be pretty
Speaker 2: cool to take advantage of that.
Speaker 1: I loved those so much when I was a kid.
Speaker 1: I'd have my mom pull up a little farther so
Speaker 1: that I could be the one to press the button.
Speaker 1: And oh man, it was better in the eighties and
Speaker 1: the nineties. No, it wasn't.
Speaker 2: So if we're still discovering essential components of the cell
Speaker 2: that make up a significant fraction of its volume, are
Speaker 2: there still things that we haven't figured out their discoveries
Speaker 2: in the future, like big parts of the cell that
Speaker 2: we have never seen. For whatever reason, I.
Speaker 1: Feel like there's gotta be Like I have this vague
Speaker 1: memory of not that long ago, there was like another
Speaker 1: major nerve that was discovered, and I think the idea
Speaker 1: was that we had like mapped out the nerves in rodents,
Speaker 1: and so we thought we knew where they all were.
Speaker 1: But turns out humans have another one that we had
Speaker 1: sort of missed until recently, and which is not too surprising.
Speaker 1: But I do think there's still surprises left to be uncovered.
Speaker 2: Yeah, well, that's what makes biology exciting, right. Not only
Speaker 2: is it super relevant, but there's lots of unanswered questions.
Speaker 1: Right. And speaking of unanswered questions, Rian, is this giant
Speaker 1: shrug that we're sending your way sufficient to answer the
Speaker 1: question that you sent us?
Speaker 3: Let's find out, ah, Kelly, Wow, as far as shrugs go,
Speaker 3: that was spectacular. Yes, if you're gonna have a non answer,
Speaker 3: it can be a non answer full of so much
Speaker 3: interesting information. I think that's even better than knowing what
Speaker 3: it is. What an incredible mystery. We have quadrillions of
Speaker 3: these things, and the answer so far is maybe they
Speaker 3: don't do much at all.
Speaker 4: Wow.
Speaker 3: Wow, that's gonna keep me thinking for ages. Yeah. That's brilliant.
Speaker 3: Thanks so much. I knew you guys would make something
Speaker 3: great out of this, and I'm so glad I found
Speaker 3: something that was new to you as well. I'm definitely
Speaker 3: gonna refer to them as organitos from now on too.
Speaker 3: That's adorable.
Speaker 6: Thank you, Okay, we are back and we are answering
Speaker 6: questions today from the tiny little things in your cell
Speaker 6: to the tinier little things that they.
Speaker 2: Are made out of. And now we have a question
Speaker 2: from Kurt about particles and fields and what's possible out
Speaker 2: there in the universe.
Speaker 4: I know in quantum mechanics there are fields and can
Speaker 4: become excited to form particles, like you got the electromagnetic
Speaker 4: field with the photon, the Higgs field with the Higgs boson.
Speaker 4: Could there be a quantum field where it's not possible
Speaker 4: to form a particle. I've never heard of such a thing,
Speaker 4: so was wondering if there always must be at least
Speaker 4: one particle for each field. Thanks.
Speaker 1: Ah, this is another one of those great questions where
Speaker 1: it made me think, oh, yeah, I've heard Daniel say
Speaker 1: stuff over and over again and never thought, oh, well,
Speaker 1: what about blah blah blah. So I guess I had
Speaker 1: always thought of quantum fields as being sort of like
Speaker 1: a wave, and I guess that makes me think of
Speaker 1: the ocean, and ocean waves have ripples. Is a field
Speaker 1: more like a blanket held taut without ripples? Like what
Speaker 1: does a field look like?
Speaker 2: Yeah, that's a great question. And the answer depends on
Speaker 2: the temperature. Like in the early universe, when all the
Speaker 2: fields were totally filled with energy, a big, frothing mess.
Speaker 2: It was more like the ocean, and you wouldn't think
Speaker 2: about like individual drops to it didn't really make sense.
Speaker 2: But now the universe is old and cold and dilute,
Speaker 2: and the energy is mostly spread out, and for most
Speaker 2: of the universe the fields are empty. It's more like
Speaker 2: a dried up sea bed with a few droplets on it, right,
Speaker 2: And those droplets are what we call particles, And so
Speaker 2: it sort of depends a little bit what phase of
Speaker 2: the universe we're talking about. But I want to congratulate
Speaker 2: Kurt on asking this question for exactly the reason that
Speaker 2: you just mentioned. I think to really understand something, you
Speaker 2: have to ask yourself questions about it. You're like, all right,
Speaker 2: you're telling me it works like this, but then what
Speaker 2: about this scenario or what about the opposite, or does
Speaker 2: this have to be true? And it's that process of
Speaker 2: like turning it around in your head and poking it
Speaker 2: from all sides that builds that model in your mind
Speaker 2: that lets you then manipulate it and then become fluent
Speaker 2: in it and that's what doing physics is. So congrats Kurt,
Speaker 2: and I want to encourage everybody out there when you
Speaker 2: hear an explanation on the show, really try to do that.
Speaker 2: Say does this connect with this other understanding or what
Speaker 2: are the limitations or in what situations does that break down?
Speaker 2: And if it's not connecting in your head right to me,
Speaker 2: I will help you sort it out, or.
Speaker 1: We will sort it out for other people, because I
Speaker 1: think a lot of times when the listener has a question,
Speaker 1: that's a question that a lot of people have either
Speaker 1: thought or if they didn't think it themselves, when you
Speaker 1: say it, they're.
Speaker 2: Like, oh yeah, what about yeah exactly.
Speaker 1: Which was certainly my response when I read this question.
Speaker 2: So let's dig in by reminding ourselves what we mean
Speaker 2: when we say particles are ripples and quantum fields? What
Speaker 2: is that anyway? And it's sort of a historical tour
Speaker 2: through what we've thought about particles, And check out our
Speaker 2: whole episode on what is a particle anyway? The short
Speaker 2: answer to which is we're really not sure, but we
Speaker 2: have some models for it that are probably wrong. But
Speaker 2: you know, his hysics somehow a head of biology, but
Speaker 2: still getting nowhere. So intuitively, you might think of a
Speaker 2: particle as like a tiny little dot of matter, and
Speaker 2: that's what we thought, like one hundred and fifty years
Speaker 2: ago discovery the electron. We're like, okay, there's something inside
Speaker 2: matter that has spin and charge and mass and all
Speaker 2: this kind of stuff, So start with a little dot
Speaker 2: of manner. But then we saw that these things were
Speaker 2: actually controlled by wave like mathematics, you know, we saw
Speaker 2: interference effects. We're like, it doesn't really make sense to
Speaker 2: think of this as a tiny speck. It's really more
Speaker 2: like a wave. Then we introduce this quantum wave function,
Speaker 2: which is controlled by the Schrodinger equation and tells particles
Speaker 2: where to go essentially, and we have this confusing particle
Speaker 2: wave duality, which I think is more misleading than clarifying,
Speaker 2: because really it's all about the wave. The particle is
Speaker 2: the observation where you see the wave, but the wave
Speaker 2: controls everything. It tells you where the particles can go.
Speaker 2: Like in relation to quantum smin as we were talking
Speaker 2: about earlier, the wave function tells you do you have
Speaker 2: a forty percent probability of going left or sixty percent
Speaker 2: probability or a zero percent probability? The wave controls everything.
Speaker 2: We discovered like fifty years ago that there was also
Speaker 2: sort of an important limitation there, which is it really
Speaker 2: only lets you think about one particle, Like you have
Speaker 2: an electron flying through space. You can describe the wave
Speaker 2: function of it and what's going to happen whatever, And
Speaker 2: it's hard to talk about two electrons or twenty electrons,
Speaker 2: and what about electrons that are being created and destroyed constantly.
Speaker 2: It's sort of like trying to tell a story about
Speaker 2: one electron, but it's really just part of a larger tapestry.
Speaker 2: And now you have lots of stories you're trying to
Speaker 2: all tell. People found a way to unify all those
Speaker 2: individual stories together into a field theory. So rather than
Speaker 2: talking about any individual particle, they're like, let's think about
Speaker 2: all these different waves as part of one bigger sheet there.
Speaker 2: Instead of having this wave over there and that wave
Speaker 2: over here, let's integrate them into being ripples in one
Speaker 2: unified field.
Speaker 1: So when I'm trying to picture a ripple, should I
Speaker 1: picture a bunch of electrons? And like, you know, so
Speaker 1: I'm thinking about like a sine wave even like the amplitude,
Speaker 1: is it a bunch of them coming together? To form
Speaker 1: an amplitude or is each wave a separate particle? What
Speaker 1: constitutes a ripple?
Speaker 2: I think the closest description is that each wave is
Speaker 2: a separate particle, and art with a classical field theory
Speaker 2: like electromagnetism, we say that photons are ripples in electromagnetic fields.
Speaker 2: And Maxwell understood this long before we had quantum mechanics,
Speaker 2: and he thought about photons as like, Okay, you have
Speaker 2: a ripple propagating through the electromagnetic field. But let's be
Speaker 2: clear about what that means, because a lot of people
Speaker 2: are imagining something moving like a sign wave, like it
Speaker 2: moves up, it moves down, it moves up, it moves down.
Speaker 2: That's not what's happening, right. A photon moves in a
Speaker 2: straight line. What's oscillating is the field. What is a
Speaker 2: field anyway? Exactly? A field is a number at every
Speaker 2: point in space. So imagine a cube of blank space, right.
Speaker 2: All you have in your mind right now is just
Speaker 2: a black cube, and then at every point in that space,
Speaker 2: put a number. There's a seven here, there's a zero there.
Speaker 2: It's mostly zeros, right, So put all zeros in your field,
Speaker 2: and put a one in one spot and then how
Speaker 2: that one move through the field. That's a ripple in
Speaker 2: a field. Right now, you can describe the relationship between
Speaker 2: numbers of different points in space using a mathematical function.
Speaker 2: So instead of having a one, have like a one
Speaker 2: and then a zero, and then a minus one, and
Speaker 2: then a zero, and then a one and then a
Speaker 2: zero and then a minus one. That's like a sine
Speaker 2: wave right now. It's not moving up and down. It's
Speaker 2: the values of the field itself that are described by
Speaker 2: the mathematical function. So that's the ripple. It moves along
Speaker 2: the line like a photon moves in a straight line.
Speaker 2: It doesn't go up and down or side to side
Speaker 2: or anything like that. But the values of the field
Speaker 2: along that line are changing. And a photon is more
Speaker 2: complex than just one number. It's a vector, so at
Speaker 2: every point in space it has a direction as well
Speaker 2: as a magnitude. You don't need to understand that in
Speaker 2: all of its detail. But the point is the particle
Speaker 2: is a ripple in the values of the field. It's
Speaker 2: not physically wiggling through space.
Speaker 1: Got it, all right? I feel like I have a
Speaker 1: much better visualization now.
Speaker 2: All right, So that's classical electromagnetism and understanding the photon
Speaker 2: is a ripple in that field. But what we do
Speaker 2: now are quantum fields. We say, all right, the field
Speaker 2: can't just have any value, like at that point in
Speaker 2: space you could have a zero or one, or a
Speaker 2: zero point seven, two nine, or a one point four
Speaker 2: to twenty seven. There are only certain values allowed. There's
Speaker 2: a ladder of possible values, and so you can have
Speaker 2: like a zero, or you can have a one point seven,
Speaker 2: or you can have a three point four, you can
Speaker 2: have a fourteen point one. There's a certain set of
Speaker 2: values there that are allowed, and those are the ones
Speaker 2: that are solutions to the quantum equations. Like quantum equations
Speaker 2: don't have solutions for every value. They have a ladder
Speaker 2: and that comes out of the mathematics of quantum field theory,
Speaker 2: and it comes from constraints and boundary conditions. And you know,
Speaker 2: we don't have to necessarily get into why quantum field
Speaker 2: equations have only certain values, but they do. And when
Speaker 2: you take a classical field theory and you quantize it,
Speaker 2: what that means is you're imposing the mathematics on it
Speaker 2: that generate only a certain spectra of solutions. So now
Speaker 2: you have your quantum field, and it can either be
Speaker 2: zero or it can have the first solution or the
Speaker 2: sex and solution or the third solution, and we call
Speaker 2: that having zero particles or one particle, or two particles
Speaker 2: or three particles. So the number of the step you
Speaker 2: are in the latter is the number of particles we
Speaker 2: consider in the field.
Speaker 1: Okay, so inside of that box, there's a finite number
Speaker 1: of ripples that could happen because there are steps and
Speaker 1: you can only take certain steps. And it's a big number.
Speaker 2: Not necessarily a finite number. You could have an infinite number,
Speaker 2: but they're discrete, right, There's not any possible number could
Speaker 2: be a solution. There might be an infinite number of solutions, right,
Speaker 2: but there are gaps between the solutions.
Speaker 1: All right, got it?
Speaker 2: And so that's what we say. Like the field is
Speaker 2: in state two, that means there are two particles. The
Speaker 2: field is in state nineteen, there are nineteen particles there.
Speaker 2: So that's what we mean when we say the particle
Speaker 2: is a ripple in the field. It means that there
Speaker 2: are solutions to the field equations, and they're just like
Speaker 2: the Schrotinger equation, but they're sort of generalized to describe
Speaker 2: more than one potential particle, and they can describe multiple
Speaker 2: particles moving through the field, like photons. The electromagnetic field
Speaker 2: can have lots of photons. There are lots of photons
Speaker 2: in the universe. There are all ripples in the same field.
Speaker 1: Right, What is a particle, It's a state in the field.
Speaker 1: So state in the field just tells you how many
Speaker 1: particles are in the box, or how many particles are
Speaker 1: possible at a particular location in the box.
Speaker 2: Yes, so at any particular place in the field, there
Speaker 2: are solutions, and those solutions are localized because particles aren't
Speaker 2: the whole universe. Some of them are actually bigger than others.
Speaker 2: Depends a little bit on their momentum, Like if you
Speaker 2: know it's momentum really really well, then it's uncertain over space,
Speaker 2: and particles can actually be spread out across really vast
Speaker 2: distances in the field. That's a whole other confusing thing.
Speaker 2: But essentially you can have particles at different locations, but
Speaker 2: at each location you can say I have one particle
Speaker 2: or two particles, And some fields can have multiple particles
Speaker 2: in the same place on top of each other, like
Speaker 2: you can have nineteen photons in the same place the
Speaker 2: field is fine with that. You can't do that for
Speaker 2: electrons because electrons are different kind of particle. They're fermions.
Speaker 2: They don't like to occupy the same place at the
Speaker 2: same time unless they have something else about them that's different,
Speaker 2: like their spin is different or something. So they obeyed
Speaker 2: different sort of quantum rules because the field itself is
Speaker 2: different and so the solutions come out differently. So some
Speaker 2: fields you can only have zero one particles. Other fields
Speaker 2: you can have like as many particles as you want, okay,
Speaker 2: And there's lots of different kinds of fields. Like the
Speaker 2: simplest field is the Higgs field. The Higgs field is
Speaker 2: just a number in space. You might hear described as
Speaker 2: a scaler field. That's what it means. It means just
Speaker 2: a number. Scaler is a fancy way of saying a number.
Speaker 2: Other fields are spinner fields, which are like numbers, but
Speaker 2: they also have another dimension which can be up or down,
Speaker 2: like electrons we talked about, kind of spin up or
Speaker 2: spin down. There's spinner fields they have two possible numbers there,
Speaker 2: and there's vector fields like photons have three possible numbers.
Speaker 2: And there's even more complicated fields that you can have
Speaker 2: a tensor. A tensor is like a vector, but more
Speaker 2: like a matrix, right, So it's like many possible values there,
Speaker 2: So it gives very complex behavior. And if gravity, for example,
Speaker 2: is a quantum field, people think it has to be
Speaker 2: a tensor field, which makes the graviton a very complicated
Speaker 2: particle with five possible spin states, et cetera.
Speaker 1: No wonder, y'all haven't figured that out yet.
Speaker 2: Gravity is hard anyway. Fields can do all sorts of
Speaker 2: really complicated stuff. They can interact. You can get energy
Speaker 2: going from one to another, which is how we describe
Speaker 2: particle interactions. But at the end of the day, when
Speaker 2: we say a particle is a ripple, we mean that
Speaker 2: there is a field there with a ladder of solutions,
Speaker 2: and the number of particles is sort of like which
Speaker 2: solution are you on? If you're on the fourth solution
Speaker 2: from the bottom, we say there are four particles there.
Speaker 1: All right, So it sounds to me like in order
Speaker 1: to have anything that qualifies as a field, there has
Speaker 1: to be some particles there, right. The answer can't be
Speaker 1: zero in every location.
Speaker 2: Yeah, it's a great question, Kurt asks, and your answer
Speaker 2: is actually really cool. One I mean, I think Kurt
Speaker 2: is asking if there's a field where you couldn't possibly
Speaker 2: have particles. It's totally possible to have a field that's
Speaker 2: empty of particles, where there's possibilities for particles, you just
Speaker 2: don't have the energy, right, there's just not enough energy
Speaker 2: to make any particles. That's totally possible. I think Kurt's
Speaker 2: asking a different question, which is, could you have a
Speaker 2: quantum field where no particle is even ever possible, where
Speaker 2: just can't do that kind of ripple. It's a really
Speaker 2: interesting question because you might think, like, well, particles are
Speaker 2: a special kind of ripple in these fields, and it
Speaker 2: has to solve the equation, and could you have a
Speaker 2: field whose basic properties prevent there from ever being any
Speaker 2: solution like that? Like are there fields with no solutions
Speaker 2: at all? And it's a really good deep question about
Speaker 2: quantum field theory. The answer is basically no, because the
Speaker 2: simplest field you can imagine like the Higgs boson, but
Speaker 2: then even remove all of its interactions, the simplest field
Speaker 2: has to have some kinetic energy, has to be able
Speaker 2: to wiggle. That's what fields can do. And as long
Speaker 2: as you have a field that can have kinetic energy,
Speaker 2: and it basically motion, and then you can find quantum solutions.
Speaker 2: So essentially every quantum field, by its nature, has quantized solutions,
Speaker 2: and steps on that ladder are particles, and so essentially
Speaker 2: every possible quantum field has particle solutions to it. Even
Speaker 2: the very simplest scenario, even the most basic, minimalized, bare
Speaker 2: bones field, would have particles in it.
Speaker 1: What I love about this question is that it seemed
Speaker 1: like it was going to be very simple. Even simple
Speaker 1: questions can be deceptively sort of complicated to really understand
Speaker 1: them completely. But I learned a lot. Let's see if
Speaker 1: Kurt did.
Speaker 4: I also learned a lot. Thank you so much for
Speaker 4: the response. I found it quite interesting and thought provoking.
Speaker 4: I haven't thought about how quantum field theory generalizes from
Speaker 4: the simpler classical field description with Turner's equation, the idea
Speaker 4: that each solution to the field equation corresponds to the
Speaker 4: number of particles. That makes perfect sense. Your answer helped.
Speaker 4: Thank you.
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