Speaker 1: Hey, Daniel, do you get tired of answering questions? Oh? Never,
Speaker 1: I love our listener questions. I just mean questions in general,
Speaker 1: like about the universe, about your personal life, poor like
Speaker 1: this question you're asking me now from your podcast host partner. No,
Speaker 1: people ask me questions all the time, but it's fun
Speaker 1: to answer them. You know, sometimes I wish I got
Speaker 1: asked more science questions, you know, sometimes with questions are
Speaker 1: more prosaic. But about your kids? And your kids constantly
Speaker 1: pester you with science questions too, I wish they asked more.
Speaker 1: You know. It's the occasional like what does the black
Speaker 1: hole look like? But more often it's like can I
Speaker 1: have more dessert? Or how could my sister just to
Speaker 1: use the iPad more than I do? And the answer
Speaker 1: is always the same. Nobody knows that we have no idea.
Speaker 1: They're kind of six questions too, aren't they? Like? Um,
Speaker 1: they're about time? Who gets more time on the iPad?
Speaker 1: Or matter who gets more desserted? Exactly? And what about you?
Speaker 1: Your kids ask you science questions? Uh? They do, yeah,
Speaker 1: pretty pretty often. I think my kids, um like to
Speaker 1: read and sometimes they kind of make connections in their
Speaker 1: head and they ask me questions. And what do you
Speaker 1: do when they ask you questions if you don't know
Speaker 1: the answer. What do you mean you assume that I
Speaker 1: don't know the answers. I often don't know the answer,
Speaker 1: so I assume not everybody has all the answers. Sure, no,
Speaker 1: Well I do my best. I guess um and maybe baby. Mainly,
Speaker 1: I just tell them to send their questions into our
Speaker 1: podcast so that you can answer them. That sounds good.
Speaker 1: I'm glad to be your backup science parent. I mean,
Speaker 1: what's the whole point of befriending as physicists if not
Speaker 1: to get these questions answered? I knew, just would you
Speaker 1: want to be friends with the physicists? I knew? I
Speaker 1: felt used. Now I know why. Hi am Jorge. I'm
Speaker 1: a cartoonist and the creator of PhD Comics. Hi I'm Daniel.
Speaker 1: I'm a particle physicist and a backup science parent for
Speaker 1: many people out there. And welcome to our podcast, Daniel
Speaker 1: and Jorge Explain the Universe, a production of I Heart
Speaker 1: Radio in which we take funny, weird, amazing, crazy things
Speaker 1: about the universe and explain them to you so that
Speaker 1: you can explain them to your kids or your parents
Speaker 1: or just sit them down with with our podcast as
Speaker 1: free babysitting. That's right. Yeah, so we we love answering questions,
Speaker 1: right Daniel. Oh yeah, it's really fun because we can
Speaker 1: think about the universe and we can talk about what's
Speaker 1: exciting for us. But the most is interesting is answering
Speaker 1: questions from listeners because it reveals what they understand and
Speaker 1: what they own't and what they're wondering about, what all
Speaker 1: those collective brains out there are cognating on. Yeah, so
Speaker 1: if you don't know this already, we actually answer people's questions.
Speaker 1: If we have an Instagram account, on Twitter account, on
Speaker 1: Facebook account, and if you post a question, well, first
Speaker 1: of all, follow us there, but if you post a question,
Speaker 1: most likely Daniel will answer the question, right Daniel, or
Speaker 1: at least maybe one of your regrets, that's right. No,
Speaker 1: I'll answer questions via email or Twitter or Facebook. I'll
Speaker 1: be honest, though, I don't use Instagram, so all those
Speaker 1: people asking physics questions on Instagram are just questioning into
Speaker 1: the void. Sorry, folks. The question is does anyone use
Speaker 1: Instagram anymore? Now that I don't, I think the question
Speaker 1: is who doesn't use Instagram these days? Just me, I guess,
Speaker 1: I guess just physicists, you know. But it's wonderful. We
Speaker 1: hear questions from all over the world, and sometimes there
Speaker 1: are questions people just had in their minds they wanted
Speaker 1: to know the answers to, and those are wonderful. But
Speaker 1: also sometimes the questions are in reaction to something we
Speaker 1: talked about on the show. You know, on the show,
Speaker 1: we do our best to think, what's confusing about this?
Speaker 1: How do we explain this? How do we make something clear?
Speaker 1: But we never can completely succeed. So it's really nice
Speaker 1: to have feedback when people say you said X, but
Speaker 1: then I that made me wonder why, and that helps
Speaker 1: us be more clear in the future. So please send
Speaker 1: us feedback, send us questions, send us presents, send us gags,
Speaker 1: send us whatever you have at Mostly you send us
Speaker 1: money please, I mean, how much do you think podcasting? Me? Podcaster?
Speaker 1: That's right? And sometimes people send us serious questions about
Speaker 1: the universe. And then sometimes people send us silly questions. Yeah,
Speaker 1: like what's been a silly question? All right, here's a
Speaker 1: question we got on Twitter from Patrick Nouman. He says,
Speaker 1: Dear Daniel and Jorge, I've got a question that really
Speaker 1: want to get answered. How heavy would a blob or
Speaker 1: banana bee of all of the photons in sun? And
Speaker 1: how big would it be? Oh? Interesting, So you took
Speaker 1: all the photons in the sun and somehow, what do
Speaker 1: you think, transformed them into a banana or put them
Speaker 1: in the space shaped them into a banana? What do
Speaker 1: you think I actually started trying to work on this question.
Speaker 1: At first, I thought, well, how many photons are in
Speaker 1: the sun, right, like, is that a number? Um? You know,
Speaker 1: and it's pretty tough. But it turns out you can
Speaker 1: do a rough calculation and the sun creates ten to
Speaker 1: the forty five photons per second. That's ten with that's
Speaker 1: a lot of photons, a lot of like trillion, billy
Speaker 1: busily but gillions, yes, exactly, billions and yeah, exactly. But
Speaker 1: not all those photons escape the sun. You know, the
Speaker 1: sun is a huge ball of plas and most of
Speaker 1: the stuff that's made by the Sun is then just
Speaker 1: reabsorbed by the Sun, and so only things that actually
Speaker 1: penetrate leave the Sun and hate your eyeballs arrive here
Speaker 1: on Earth. That's a tiny fraction what comes out of
Speaker 1: the Sun. But anyway, let's say you had ten to
Speaker 1: the forty five photons. Okay, that's a huge amount of
Speaker 1: energy um. And then this question is interesting. He said,
Speaker 1: how big would that be? Right? Like if you had
Speaker 1: a pile of tending the forty five photons, right? How well?
Speaker 1: How how how close together can you cram them in? Maybe? Yeah,
Speaker 1: And that's really interesting because there's no limit on how
Speaker 1: close you can cram photons together. That's not true ordinary
Speaker 1: matter like electrons and other particles. These things are fermions,
Speaker 1: and fermions are different from photons and other kind of
Speaker 1: particles that we call bosons because fermions have to have
Speaker 1: different quantum states. No two of them can be in
Speaker 1: the same quantum state. They can literally be on top
Speaker 1: of each other. That's impossible, that's right. They have to
Speaker 1: have some difference, like you can have two electrons in
Speaker 1: the same level of energy in a in an atom,
Speaker 1: but then they have different have to have different spins
Speaker 1: or something different about them, and so fer meons have
Speaker 1: to be distinguishable, whereas bosons, these are particles with integer
Speaker 1: spin like a photon. They can be right on top
Speaker 1: of each other. They can be exactly the same place,
Speaker 1: have the same momentum, had the same everything. I feel
Speaker 1: like the silly question is is gotten a little seriously Yeah,
Speaker 1: serious physics, yea, even silly questions reveals something interesting about
Speaker 1: the universe. And so you can have ten to the
Speaker 1: forty five photons on the head of a pin, basically
Speaker 1: right or on top of each other. You're saying, yes, exactly,
Speaker 1: all on top of each other in a tiny, tiny space.
Speaker 1: So thank you Patrick for sending in that hilarious question.
Speaker 1: It really made us think, and there really is some
Speaker 1: physics in that question, even in silly questions. Well, we
Speaker 1: do have three questions today from listeners, and so that
Speaker 1: is the topic of today's podcast. To be on the podcast,
Speaker 1: we'll be talking about listener questions five point five point
Speaker 1: one five point one because we because we just answered
Speaker 1: Patrick's questions, so we got to add a little that's right.
Speaker 1: We're part way through this episode already. Um, that's right.
Speaker 1: We'll be answering questions about electrons, about space, about stars,
Speaker 1: about black holes, questions from far away, and questions from
Speaker 1: surprisingly nearby. Yeah, and we might even know the answer
Speaker 1: to some of these questions this time, and if we don't,
Speaker 1: will speculate hilariously. All right, let's jump right into it. Daniel, there,
Speaker 1: Our first question today is from this really pretty cool guy,
Speaker 1: fun guy, one of maybe one of my favorite people,
Speaker 1: has a great dad. Yeah, so this is a question
Speaker 1: from Oliver from southern California. What if for whole solar
Speaker 1: system is in a black hole and we don't notice? Wow,
Speaker 1: that's a deep question. His voice sounds a little familiar
Speaker 1: to me. Yeah. What a what a smart sounding little kid.
Speaker 1: He sounds like he might grow up to be a cartoonist.
Speaker 1: Well not if he's that smart, hopefully. So yeah, that's
Speaker 1: my son who just asked that question in and he
Speaker 1: just turned to me one day, Well, what happened? What?
Speaker 1: He was reading our book? So we, Daniel and I
Speaker 1: wrote a book called We Have No Idea, A Guide
Speaker 1: to the Unknown Universe, available now in Amazon dot com.
Speaker 1: And and you can verify it's been read by at
Speaker 1: least one person since your son is reading it. That's right,
Speaker 1: that's right. He's under age, but he still counts as
Speaker 1: a person. He's nine years old, and so he's been
Speaker 1: reading our book and I always kind of wonder how
Speaker 1: much of it he's getting. You know, he's nine, he's
Speaker 1: in third grade. Um, but he seems to be enjoying it,
Speaker 1: and he keeps reading it, and so one day he
Speaker 1: just turned to me and he asked me this question, right,
Speaker 1: and what do you think is behind the question? What
Speaker 1: do you think he's wondering? Explain the question to me?
Speaker 1: Even explain my son do a deep dive. If I
Speaker 1: knew that answer, Daniel, if I could explain my son,
Speaker 1: my parenting experience would be so much. You know, I
Speaker 1: thought it was really interesting. One part of his question says,
Speaker 1: what if our whole solar system is in a black hole? Cool? Fascinating, Yeah,
Speaker 1: But then he says, and we don't don't even notice?
Speaker 1: Like I think that taps into you know, is the
Speaker 1: universe different from how we expected? Is it possible that
Speaker 1: we think we're living in universe X, but we're actually
Speaker 1: living in universe? Why? You know? I think he was
Speaker 1: probably kind of reading about black holes and he just
Speaker 1: kind of wondered, like, what what if? What if we're
Speaker 1: inside of a black hole? Is that possible? Like could
Speaker 1: the universe? Or or like could could a solar system
Speaker 1: exists inside of a black hole? And you know we
Speaker 1: don't even know it? Yeah, And I think there's something
Speaker 1: wonderful there about the feeling that maybe, you know, the
Speaker 1: universe could be revealed to be totally different from what
Speaker 1: you expected, because that's precisely happened a lot of times
Speaker 1: in history, right, we thought, oh, the universe works this way. Nope,
Speaker 1: it's totally different from what you imagined. And those are
Speaker 1: the best moments in physics. So to hear your son
Speaker 1: like sort of wondering if he's coming to that realization
Speaker 1: him self, or wondering if this kind of realization is
Speaker 1: around the corner, that's fantastic. He's been bitten by the
Speaker 1: physics bug, so be careful. Oh no, he's gonna be
Speaker 1: like Spider Man. Well that's only if he's bitten by
Speaker 1: a radioactive physicist. Okay, radioactive. Well I grew up in
Speaker 1: Los Alamos, so maybe I'm especially radioactive. But I'll do
Speaker 1: my best not to not to about your son. Yeah,
Speaker 1: but let's break it down. Um, it's interesting question. And
Speaker 1: you know, something that's important to think about is sort
Speaker 1: of the size of a black hole, like, could our
Speaker 1: entire solar system fit into a black hole? Well? Right,
Speaker 1: the size of a black hole is really we can
Speaker 1: usually consider that to be the size of the event
Speaker 1: horizon that's the point, right, the black style. Yeah, like
Speaker 1: the point return. Look at a black hole, it would
Speaker 1: look like a black sort of sphere, and so the
Speaker 1: size of that sphere, that's the size of the black yeah. Yeah,
Speaker 1: And if you go past that point, you can't escape, right.
Speaker 1: And nobody knows what's inside of a black hole, but
Speaker 1: we know how to calculate the size of the horizon.
Speaker 1: It's determined just by the amount of stuff in the
Speaker 1: black hole. So the more mass in the black hole,
Speaker 1: the stronger the gravitational pull. The farther away it can
Speaker 1: grab stuff and never let go, right, So the size
Speaker 1: of the black hole is determined by its mass. So
Speaker 1: how much stuff is in our solar system? Well, basically
Speaker 1: the first approximation our solar system is just a soun.
Speaker 1: Like the rest of the stuff in the solar system Jupiter, Mars,
Speaker 1: me you hamsters, all that stuff is negligible. It's a
Speaker 1: tiny fraction of the mass of the solar system. So
Speaker 1: basically you can ask, like, if you had a black
Speaker 1: hole with the mass of our Sun, how far away
Speaker 1: would the event horizon B would it be out past
Speaker 1: the edge of the black of the solar system? Is
Speaker 1: it possible to fit a solar system in a black
Speaker 1: hole that has the mass of our Sun. It's sort
Speaker 1: of the way I interpret the question. So you're interpreting
Speaker 1: the question as could our solar system be a black hole? Yeah? Exactly?
Speaker 1: Could we be inside a black hole right now? Is
Speaker 1: there enough room in a black hole with the mass
Speaker 1: of the Sun to fit the entire solar system? So
Speaker 1: could we be in a hole where the only thing
Speaker 1: inside of it is our solar system? Yeah? Exactly exactly
Speaker 1: is how you're interrupting the question. And the answer to
Speaker 1: that is no, Because a black hole that has only
Speaker 1: the mass of our sun, the event horizon would only
Speaker 1: be three kilometers from the center of the Sun, and
Speaker 1: so that definitely wouldn't be big enough to have the
Speaker 1: whole solar system in it, because the solar system is
Speaker 1: a lot more than three kilometers. It's one billion kilometers wide.
Speaker 1: So we couldn't be in a black hole where the
Speaker 1: only thing in it was our solar system. But is
Speaker 1: it possible that we are that our solar system is
Speaker 1: inside of somebody else's black hole? You know what I mean? Like,
Speaker 1: maybe there's a black hole out there with a lot
Speaker 1: of mass inside of it and we are just inside
Speaker 1: of the event horizon of that black hole floating around. Yeah,
Speaker 1: that's possible. Right, Let's let's consider that for a moment. So,
Speaker 1: what if there's a really ends blobs somewhere else sort
Speaker 1: of nearby, and that makes a black hole that's big
Speaker 1: enough to encompass us, and we're inside that black hole
Speaker 1: right right right, Well that's possible, but it's difficult to
Speaker 1: imagine because such a huge mass would have a big
Speaker 1: effect on us. You know, if there was a like
Speaker 1: if there's a really big mass somewhere else inside our
Speaker 1: Solar system next to the Sun, like an invisible huge
Speaker 1: blob of dark matter, that that made their enough mass
Speaker 1: so that the black hole was big enough, we would
Speaker 1: definitely notice that that would affect the orbit of the planets.
Speaker 1: What if there was another big mass kind of far
Speaker 1: away but close enough that we were still inside the
Speaker 1: event horizon, Well, you're talking about still really strong gravity.
Speaker 1: So it's hard to imagine having some enormously powerful gravitational
Speaker 1: attractor nearby and not having it disturbed like the orbits
Speaker 1: of the planets or even just tossing of baseballs and
Speaker 1: all sorts of stuff. So I think if you were
Speaker 1: inside a black hole that was big enough to hold
Speaker 1: a solar system, it would have to have a huge mass,
Speaker 1: and that mass would definitely be noticeable. It would affect
Speaker 1: the way things move on Earth, would it, though, Because
Speaker 1: you know, like um so so our our solar system
Speaker 1: is moving around a galaxy, right, Like, a galaxy has
Speaker 1: a lot of mass and um and it's huge, and
Speaker 1: there's a lot there's a huge black hole in the
Speaker 1: center of the galaxy, but it's not really affecting us
Speaker 1: in a local level, right, Like that gravity is kind
Speaker 1: of spinning us around the galaxy, but it's not really
Speaker 1: changing the orbits of the planets around the Sun, that's right. Yeah,
Speaker 1: And that black hole in the center of the galaxy
Speaker 1: is really massive and it's pretty big, but it's also
Speaker 1: super duper duper duper far away. Right. Any black hole
Speaker 1: that's either near enough to include us or far away
Speaker 1: but huge enough to include us still would definitely affect
Speaker 1: the gravitational poll But you know, I haven't done the calculation.
Speaker 1: There is one configuration I imagine though. Imagine our entire
Speaker 1: solar system and then it's surrounded by some enormously dense
Speaker 1: sphere of material. Okay, if you're inside a sphere of material,
Speaker 1: then the gravitational pull of that stuff doesn't affect you
Speaker 1: at all, right, because it all balances out. Is enough
Speaker 1: stuff on the left to balance the stuff on the right.
Speaker 1: Just like that episode we talked about where you jump
Speaker 1: inside the Earth. Once you get to the center of
Speaker 1: the Earth, is no gravitational force from the stuff around you. Right, Well,
Speaker 1: if you have to spear a super dense material surrounding
Speaker 1: the Solar System, right, then that might be enough to
Speaker 1: create a black hole, right that we would be inside of.
Speaker 1: We wouldn't feel the gravitational force because we would be
Speaker 1: inside all the stuff. It would be all around us. Yeah,
Speaker 1: that's what I mean. Yeah, yeah, but they have to
Speaker 1: be perfectly distributed, right. And the only reason that there's
Speaker 1: one reason to think that's not the case, and that's
Speaker 1: that we have sent stuff outside the Solar System, Like
Speaker 1: we launched probes and they're floating off into space and
Speaker 1: we're watching them and they haven't like banged up and
Speaker 1: the wall of some hugely massive blob of stuff. But
Speaker 1: what have you expand that idea even further to encompass
Speaker 1: the whole observable universe. It is possible then that we
Speaker 1: could be inside of a black hole. Yeah, yeah, it's
Speaker 1: possible the entire observable universe is inside a black hole. Yes,
Speaker 1: you can't rule that out. How do you feel about
Speaker 1: saying that on a public record, Um, I wonder if
Speaker 1: any of my colleagues are listening. No, I think it's awesome.
Speaker 1: You would be surprised. I think it's awesome, And I
Speaker 1: think sometimes these awesome questions come from the minds of children,
Speaker 1: And that's why I hope that people are listening to
Speaker 1: the podcast with their kids, because kids ask amazing questions
Speaker 1: that make us think about things we otherwise would have
Speaker 1: totally discarded that might actually be reality. Well, so that's
Speaker 1: so that's the answer. The answer is that it is
Speaker 1: totally possible that we are inside of a black hole
Speaker 1: and not knowing. Yeah, but I think our whole universe
Speaker 1: would have to be inside the black hole, not just
Speaker 1: the solar system. But yeah, that's a pretty small conviat
Speaker 1: for it for a yes answer to that question, isn't
Speaker 1: that sort of a theory out there that were like
Speaker 1: the whole universe are are inside the whole universe inside
Speaker 1: of a black hole, and there are other black holes
Speaker 1: and stuff. Like that or is that pretty fringe? I
Speaker 1: think it is the theory out there, and it's pretty fringe,
Speaker 1: But it's also totally possible, you know, like we really
Speaker 1: just we don't know what's going on inside black holes?
Speaker 1: Are there little universes in there? You know? The inside
Speaker 1: of a black hole is totally disconnected from the space
Speaker 1: that we live in, right, Like there's no way to
Speaker 1: get from here to there, right, That's why that's how
Speaker 1: a black hole works, even like can't escape it, not
Speaker 1: because it's like slowing down the light as it tries
Speaker 1: to leave, but because it's bent space in such a
Speaker 1: way that there's just no path out, like just zooming
Speaker 1: around inside the black hole. So in some ways you
Speaker 1: can think of it as sort of like a different
Speaker 1: universe disconnected from our our space, and so you can
Speaker 1: imagine then anything that goes on in there. And uh,
Speaker 1: when experiments can't constrain things, theorists minds tend to go wild,
Speaker 1: and so they think about all sorts of crazy stuff
Speaker 1: that could be inside there, insing bears or entire universes.
Speaker 1: Crazy scientists and nine year old boys whom I grew
Speaker 1: up to be crazy scientists. All right, Well, that's the
Speaker 1: answered for Oliver's son of Jorge, and I'll let him
Speaker 1: know if he has a good sum he stumped the physicists. Yeah,
Speaker 1: it's a great question. If he was Icelandic, his last
Speaker 1: name would be or Hasten exactly. All right, Well, we
Speaker 1: have two other awesome questions that we are going to
Speaker 1: answer about electron identity. I guess is that is that
Speaker 1: we would be the right topic and also about dark
Speaker 1: Matter stars, which sounds like a heavy battle band last
Speaker 1: science fiction movie. So stay tuned, will be right back.
Speaker 1: Al Right, we are back answering list are questions, and
Speaker 1: so our next question comes from Yugi from the Netherlands,
Speaker 1: and he is wondering if electrons have identity crises. That's right,
Speaker 1: And this particular listener is something of a super fan,
Speaker 1: writing to us on Twitter fairly often with insightful questions,
Speaker 1: and he sent me this one and I thought, well
Speaker 1: that's a good question, let's take it online, and so
Speaker 1: here he is, Hi, Danielle and Jorge. My name is
Speaker 1: Eugene Raudemake and I live in the Netherlands, hence the actions.
Speaker 1: I'm a big fan of your morphous poticast cities, for
Speaker 1: it makes me understand more of physics, and it makes
Speaker 1: me think a lot about the universe in general. After
Speaker 1: listening to your episode about quantum tunneling, the following question
Speaker 1: came to my mind. If an electron tapt well say A,
Speaker 1: suddenly appears in well B, how can physically still it's
Speaker 1: actually this very same electron. I realized that I had
Speaker 1: the both bowl empty swimming pool and the analogy in
Speaker 1: my mind when the Christians sue appearance in my will.
Speaker 1: Thanks for spending time answering my questions, all right, thank
Speaker 1: you for saying this question, and also for being a
Speaker 1: fan of the show. We really appreciate everyone listening out there. Yeah, exactly,
Speaker 1: And uh, it's really a wonderful question, you know. To me,
Speaker 1: it goes to the heart of like what are these particles?
Speaker 1: What are we talking about? Um? But the way I
Speaker 1: interpret his question is like, you haven't quite an electron
Speaker 1: over here, and physics tells us the electron can then
Speaker 1: later be over there. But his question is, how do
Speaker 1: you know it's the same electron? Right, because we don't
Speaker 1: have this sort of notion anymore of a classical path
Speaker 1: that you can like watch a baseball fly through the
Speaker 1: air and when a baseball, you know, when somebody hits
Speaker 1: a home run, you watch it fly. You don't ask like,
Speaker 1: is that the same baseball or is it suddenly swapped out?
Speaker 1: But with quantum mechanical particles, because you can't observe them
Speaker 1: all the way along the path, you just get these snapshots.
Speaker 1: You can sort of wonder like, how do you know
Speaker 1: that's the same electron? Maybe it's from another electron down
Speaker 1: the street, right, it's just Tom or Harry or Mary
Speaker 1: or Sally. I feel like the question is there such
Speaker 1: a thing as an electron? Is there an electron? You
Speaker 1: can say and follow it around and it has a
Speaker 1: birth in a you know, journey, and then it maybe
Speaker 1: answer at some point we can you follow an electron?
Speaker 1: Or are we getting into identity politics now? So there's
Speaker 1: electrons go back to where they came from physics. Yeah,
Speaker 1: obviously we're not qualified to dive into those topics. You know,
Speaker 1: well that's a it's a famous topic in physics, and
Speaker 1: it's something that real physicists wonder and uh. In this
Speaker 1: famous physicist, John Wheeler, he had this sort of moment
Speaker 1: of insight and I don't know if he was smoking
Speaker 1: banana peels or what. But he was wondering, like, why
Speaker 1: do all electrons behave the same way? Like you drop
Speaker 1: an electron in the in the circumstance, it's always going
Speaker 1: to get repulsed in the same way. It's not like
Speaker 1: this one's got a little bit more charge and that
Speaker 1: one's got a little bit more mass. They're all identical.
Speaker 1: They're not like scoops of ice cream, right, they all
Speaker 1: have exactly the same properties. And he had this moment
Speaker 1: of in said he thought, wait a second, maybe there
Speaker 1: is just one electron. These are all the same electron.
Speaker 1: What what do you mean, like the electrons in my
Speaker 1: body and the ones in your body, they're all the same. Yes, yes,
Speaker 1: sort of um, And I think I think that's actually
Speaker 1: sort of the answer is that the electron is not
Speaker 1: really um a particle that has an identity. It's sort
Speaker 1: of like a state of mind or a state of matter, right,
Speaker 1: because these days we don't think quantum mechanically about particles
Speaker 1: as the fundamental basis of the universe. Instead we think
Speaker 1: of fields, right, and particles are just excited states of
Speaker 1: the field. It's sort of like when you look at
Speaker 1: the ocean, you know, and you've tried to follow a wave. Right,
Speaker 1: A wave is not the basic unit of the ocean.
Speaker 1: It's the water. Right. The wave is just like, you know,
Speaker 1: the ocean has got excited a little bit by the wind,
Speaker 1: and it comes and it goes, and there's more waves
Speaker 1: behind it. It's just it's just the motion of the ocean.
Speaker 1: And that's right exactly. And so in that same way,
Speaker 1: you can think of electrons. Not a's like, here's a
Speaker 1: little chunk of matter, a little like piece of the
Speaker 1: universe we're gonna follow around. But it's just like a
Speaker 1: momentary excitation of this sort of hard to think about
Speaker 1: thing called the electron field which fills the universe. And
Speaker 1: when it gets a little bit of energy somewhere, you
Speaker 1: call that an electron. It's not an object. It's kind
Speaker 1: of a wiggle of an object. Yes, exactly, it's a
Speaker 1: wiggle of an object. And you know, this goes back
Speaker 1: to that other question we tried to answer. It's a photon,
Speaker 1: a particle, or a wave, for example, And I think
Speaker 1: I said on that podcast that it's sort of neither
Speaker 1: and sort of both, and really it's something else weird
Speaker 1: and fundamental that we just cannot understand by making analogies, right,
Speaker 1: analogies from our macroscopic experience. Things that we're familiar with
Speaker 1: just don't work because we've never seen anything like that before. Well,
Speaker 1: it turns out you can apply the same idea as
Speaker 1: to an electron also, right, an electron is both a
Speaker 1: particle and a wave and both and neither and something
Speaker 1: else totally weird. It's really just the excitation of a
Speaker 1: quantum field. And and the reason, the reason actually that
Speaker 1: we came up with quantum fields, the reason that this
Speaker 1: whole development is progress, right and not just confusion, is
Speaker 1: that it helps us think about the way particles are
Speaker 1: created and destroyed. Because when electron is flying through um
Speaker 1: the universe, it doesn't just sit around happily. It generates photons,
Speaker 1: and those photons turned into electrons and positrons which turned
Speaker 1: back into photons. Every electron is actually surrounded by like
Speaker 1: a fuzz ball of virtual particles, photons and electrons and
Speaker 1: things popping in out of the vacuum. What do you mean,
Speaker 1: like an electron is not always an electron. It's constantly
Speaker 1: kind of fuzzy and morphing and changing. Yes, exactly, it's
Speaker 1: constantly morphing and changing and it's surrounded by a ball
Speaker 1: of like almost an infinite number of low energy particles
Speaker 1: that are being created and destroyed around it. Right, And
Speaker 1: so we came up with this alternative mathematical formulation quantum
Speaker 1: field theory, because it's really hard to follow the path
Speaker 1: of an individual particle through this sort of probabilistic storm
Speaker 1: of things that's happening, and it's much easier to just
Speaker 1: think about the field that's generating all these particles. And
Speaker 1: then a particle creation and destruction is much more natural
Speaker 1: in quantum field theory than an old quantum mechanics where
Speaker 1: we try to track follow an individual particle as if
Speaker 1: it was a baseball. So we have to sort of
Speaker 1: let go of this whole idea of particles having identities,
Speaker 1: particles having paths, um and just think of them as
Speaker 1: momentary oscillations in this field. Well, I think there's several
Speaker 1: questions here, like, you know, maybe maybe you he was
Speaker 1: also thinking of the wave analogy maybe, and so maybe
Speaker 1: his question was, you know, just like you can follow
Speaker 1: a wave in the ocean, you know, if you if
Speaker 1: I make a ripple in the in the lake or something,
Speaker 1: or you've even wave is made out into the ocean.
Speaker 1: You can you can kind of follow that wave, right, like,
Speaker 1: that's wave A. I'm gonna call it Sally, and you
Speaker 1: can follow Sally as it moves across the Pacific, right,
Speaker 1: you sort of can. But what if Sally looks exactly
Speaker 1: like all the other waves, and there's billions of them,
Speaker 1: and you look away, and then you look back and
Speaker 1: you wonder which of those waves is Sally. That's the
Speaker 1: situation where the one that um like, if I see
Speaker 1: it at point A and I see at point B
Speaker 1: one second later, well that's his question, right, the one
Speaker 1: that's a point C another second later, basically right, could
Speaker 1: be or could be there along the way got turned
Speaker 1: into something else and then got turned back into a wave,
Speaker 1: And is it the same wave then? But it almost
Speaker 1: always is, isn't it? Like? Do electrons really just transformed
Speaker 1: to something else constantly when we're not looking, constantly, even
Speaker 1: while we're looking, electrons are constantly influx Yes, exactly. You
Speaker 1: know there's that even the ones that in my body,
Speaker 1: even the ones in your body, they're not special, sorry
Speaker 1: to inform you. Um, you know, there's that ancient philosophical question, right,
Speaker 1: there's some some ancient Greek ship, and every time it
Speaker 1: comes into harbor that it's lost a piece and they
Speaker 1: repair it, and then after five years there are no
Speaker 1: pieces of the original ship, and they wonder, like, is
Speaker 1: it still that same ship? You know, if it's made
Speaker 1: out of all new pieces? Um, And it's sort of
Speaker 1: that question, but it's the particle version of that question.
Speaker 1: And uh, wait, what if it rides the same wave
Speaker 1: though that the Greeks mine? Yeah, exactly, And so I'd
Speaker 1: say in this in the same way, there there is
Speaker 1: really no particle identity. Um, I don't I don't know
Speaker 1: that I've smoked enough. But An appeals to say they're
Speaker 1: all the same electron But I think sort of what
Speaker 1: he's saying is that they're all manifestations of the same field. Right,
Speaker 1: there's really just one electron field and it appears and
Speaker 1: lots of different places is in the universe. But then
Speaker 1: what's really going on? Because you know, I feel pretty consistent,
Speaker 1: you know, like I am this way sort of now
Speaker 1: and and I'm sort of the same way a second ago.
Speaker 1: I think that's my perception. Are you saying that, you
Speaker 1: know I could have changed into something totally different between
Speaker 1: now and the next second, that I am conscious about, yes,
Speaker 1: But the jorhan nous is not about the stuff that
Speaker 1: you're made up of, but the arrangement of those particles. Right,
Speaker 1: just like that ship is not about the pieces of
Speaker 1: wood that went into it, but how they're put together
Speaker 1: and what it's doing, and you know how it spends
Speaker 1: its time. And so in the same way, you are
Speaker 1: a constantly frothing mass of quantum mechanical particles. But that's
Speaker 1: not what makes you you. What makes you use the
Speaker 1: way they're arranged and the way they live their life. Well,
Speaker 1: I am a constant frothing mass of something. Sure, it's
Speaker 1: a really hard question. And you know, this is a
Speaker 1: question which is definitely on the philosophy side of the threshold.
Speaker 1: And something I love about physics is that it bumps
Speaker 1: up against philosophy so often because they're deep consequences to
Speaker 1: the answers of physics questions. And so I've always been
Speaker 1: really interested in in the philosophical implications of particle physics. Um,
Speaker 1: but I have to say it's not something that most
Speaker 1: of us, most of us particle physicists, are actually qualified
Speaker 1: to talk about, even though we do pontificate long windedly
Speaker 1: on it. Oh, I see. It's it's one of these
Speaker 1: questions that the answer is kind of like it depends
Speaker 1: on what the definition of is isuly I have to
Speaker 1: go there, but I think it applies in this case.
Speaker 1: Yeah right, It's sort of like it depends on what
Speaker 1: you mean by having an identity or being the same
Speaker 1: electron exactly, you can dig into that forever and smoke
Speaker 1: manin appeals and not necessarily make any progress exactly. Yeah,
Speaker 1: or cigars. But it's a really fun question, So thank
Speaker 1: you for asking it. Yeah, well, what's the What would
Speaker 1: you say is the answer? Then? Do electrons have an
Speaker 1: identity or can you have the same electro on? The
Speaker 1: answer seems to be I would say no. I would
Speaker 1: say identity is a macroscopic quality that we like to
Speaker 1: attribute to things because we're used to it, because we're
Speaker 1: familiar with it. We expected to tom. We expect also
Speaker 1: tiny particles to have it, but they don't and and
Speaker 1: so I think it's odd and uh, and it's it
Speaker 1: tells us more about how we think than about how
Speaker 1: the universe works. So you're saying, at the microscopic level,
Speaker 1: at the individual electron level, these things we can apply
Speaker 1: because things are just constantly changing and frothing, and yeah, exactly,
Speaker 1: I don't think it has any meaning at the microscopic level.
Speaker 1: All right, well, thank you hear you from the Netherlands
Speaker 1: for that question. Please keep listening. I hope he answered
Speaker 1: your question. Answer your question to your satisfaction. Uh So
Speaker 1: we have one more question, and this one comes from
Speaker 1: Mexico or Mexico about dark matter stars. But first let's
Speaker 1: take a quick break. Al right. Our last question of
Speaker 1: today comes from ben who is sending his question from Mexico,
Speaker 1: and he has a question about dark matter stars. Hi,
Speaker 1: Daniel lane J. This is Benjamin from Mexico, and I
Speaker 1: was wondering, if the dark matter has all these gravitational
Speaker 1: properties as the regular matter, why have an astrophysicists discovered
Speaker 1: yet a big celestial body made of dark matter, like
Speaker 1: a dark matter star or something big that we can
Speaker 1: indirectly now it's there. Thank you. All right, that's a
Speaker 1: pretty cool question. Where aren't there dark stars besides a
Speaker 1: in comic books? I think that's a comic book villain.
Speaker 1: Exactly it should be, yeah, exactly. Um No, it's an
Speaker 1: awesome question, and the way I interpret it is that
Speaker 1: he's wondering why can't we tell that dark matter is there?
Speaker 1: Why it hasn't dark matter coalesced into some sort of
Speaker 1: object that we could then pinpoint, Because I think he
Speaker 1: maybe is frustrated at the sort of diffusiveness of dark matter.
Speaker 1: We know it's there, we know it's sort of everywhere,
Speaker 1: but we can't seem to say exactly where it is
Speaker 1: and why not? Is that how you interpret the question?
Speaker 1: Why does it stay so fuzzy? Yeah? Yeah, exactly. And
Speaker 1: I think that the key thing to understand here is
Speaker 1: remember that gravity is really really weak, and it's the
Speaker 1: only way we can see dark matter so far. The
Speaker 1: only way we can feel it is through its gravity,
Speaker 1: and and so it takes a huge amount of stuff
Speaker 1: to notice something just from gravity. Remember, the gravity is
Speaker 1: so weak that you can feel the Earth's gravity, but
Speaker 1: you can't feel the gravity of your car or your house,
Speaker 1: even though there is a gravitational pull there, it takes
Speaker 1: some huge body to even feel it. Right, Well, maybe
Speaker 1: we should recap and a little bit about dark matter. Right,
Speaker 1: So we know that dark matter feels gravity, right, that's
Speaker 1: how we sort of know it's there because it's pulling
Speaker 1: us around the galaxy. But it doesn't feel electromagnetic forces,
Speaker 1: which means we can't see it or touch it. Right,
Speaker 1: that's right exactly. It doesn't give off light, it doesn't
Speaker 1: reflect light. We can't see it using any of those
Speaker 1: normal methods that we usually used to see stuff, right,
Speaker 1: But it does feel gravity, and so I think maybe
Speaker 1: Ben's question is, if dark matter feels gravity, why hasn't
Speaker 1: it clumped together out in space because it's attracted to itself, right,
Speaker 1: isn't it attracted to itself? Dark matter is attracted to
Speaker 1: itself by gravity, absolutely yes, and it has clumped together. Right,
Speaker 1: dark matter is not evenly spread throughout the universe. Dark
Speaker 1: matter has clumped together thanks to gravity, and it's formed
Speaker 1: these big blobs. And it's, in fact only because dark
Speaker 1: matter has clumped together to make these blobs that we
Speaker 1: have galaxies and we are alive, because without dark matters
Speaker 1: gravitational pull, there wouldn't be enough gravity to hold the
Speaker 1: galaxies together. And we've done simulations and seeing that in
Speaker 1: universities without dark matter, it takes a lot longer for
Speaker 1: gravity to pull all this luminous stuff together to make
Speaker 1: stars and planets and galaxies. So dark matter does make
Speaker 1: um structure, It does make objects. But those objects are
Speaker 1: sort of big and diffuse, and and they're sort of
Speaker 1: the size of the galaxy. And and you might ask, well,
Speaker 1: how do we know that the dark matter inside the
Speaker 1: galaxy hasn't also clumped together to make you know, star
Speaker 1: size stuff or planet sized stuff the way normal matter has, right,
Speaker 1: And And we don't know the answer to that, right,
Speaker 1: And the reason we don't know is because we can't
Speaker 1: see dark matter and enough to tail Like, it's totally
Speaker 1: possible that the distribution of dark matter in the galaxy
Speaker 1: is either a totally smoothly spread out right, be sort
Speaker 1: of like a cloud. Now we know it's denser towards
Speaker 1: the center and less dense towards the outside, but it
Speaker 1: could still be like a like a big cloud, right,
Speaker 1: Or it could be that their structure that it's clumped
Speaker 1: together to make, you know, a bunch of dense points,
Speaker 1: just the way normal matter has. So there could be
Speaker 1: dark matter stars or dark matter planets exactly, but the
Speaker 1: only way to see them would be through gravity. And
Speaker 1: it's really hard to see a gravity from like one
Speaker 1: planet or the gravity from one star, right unless it's
Speaker 1: really close by. Like if there were dark matter stars
Speaker 1: and a dark matter star passed near our solar system,
Speaker 1: then we could detect it the way we detect black
Speaker 1: holes right there. Black holes are invisible. We detect them
Speaker 1: from their gravity. Sometimes we detect black holes because of
Speaker 1: the X rays that are produced from compressed gas nearby.
Speaker 1: But a lot of black holes we see through their gravity.
Speaker 1: But you need to be a pretty big black hole
Speaker 1: to detect its gravity from far away or to see
Speaker 1: its gravitational effect. Are nearby stuff, right, And in fact,
Speaker 1: there are a few of these things we found, and
Speaker 1: they have a pretty silly name. You ready for it
Speaker 1: always physics really names. Yeah, they're back a long time
Speaker 1: ago before we knew whether dark matter was the thing.
Speaker 1: People were wondering if they were just big clumps of
Speaker 1: normal matter there was sort of hidden out there, and
Speaker 1: they gave them this name, massive compact halo objects, and
Speaker 1: the acronym for that is m A C h O. Right,
Speaker 1: so mach of these not nachos. Nachos are a totally
Speaker 1: different thing. These are MACHOs. And so that's not physicists
Speaker 1: over compensating for anything, not at all. No, And so
Speaker 1: people went out there and looking for these things, like
Speaker 1: can we find dark blobs out there, dark condensed blobs
Speaker 1: out there that might be responsible for all the missing mass, right,
Speaker 1: And they did find a bunch of not nearly enough
Speaker 1: to account for all the dark matter, but they found
Speaker 1: a bunch of them. They would find them like eclipsing
Speaker 1: stars or bending the path of other objects. Um. And
Speaker 1: so we know that there are dark objects out there.
Speaker 1: Some of them could be dark matter, right, Some of
Speaker 1: them could be so totally possible that dark matter has
Speaker 1: clumped these objects together. We just don't have the gravitational
Speaker 1: sensitivity to see them because they're too small. Essentially, in
Speaker 1: gravity is so weak, Like our ability to notice or
Speaker 1: feel or see dark matter is not at the planet
Speaker 1: or at the star level. It's only at sort of
Speaker 1: the galaxy level, yeah, exactly a little bit less than
Speaker 1: the galaxy. We can we can get some sense of
Speaker 1: where they are based on how rotations vary as a
Speaker 1: function of the radius from the center of the galaxy.
Speaker 1: But roughly yet much more the galaxy level than the
Speaker 1: star level. But but it's fun to think about, like
Speaker 1: imagine what would happen. What would happen if you had
Speaker 1: a huge blob of dark matter and it coalesced into
Speaker 1: sort of a tight blob, like would it make a
Speaker 1: star like planet? You know? And we when we say
Speaker 1: a star, we sort of mean something that's big enough,
Speaker 1: has enough gravity that it's pushed the stuff together that
Speaker 1: begins to fuse and release energy, right, And so another
Speaker 1: interesting question is like, what would happen if you squeeze
Speaker 1: that much dark matter together? What interesting things happen, like, um,
Speaker 1: you know, elements fusing and releasing photons and things like that. Well,
Speaker 1: we don't know, but we know it's not made of elements, right,
Speaker 1: It's not made of atoms. It's made of some some
Speaker 1: other kind of matter. And the only interaction we know
Speaker 1: it has is gravity. So as far as we know,
Speaker 1: it would just squeeze and squeeze and squeeze and squeeze,
Speaker 1: and there's no repulsion. Right. The thing that keeps a
Speaker 1: star or a planet from immediately becoming a black hole
Speaker 1: are the other forces. It feels like electromagnetism, which and
Speaker 1: the strong force which fuel fusion, right, which keeps a
Speaker 1: star exploding. It keeps it from collapsing immediately. So if
Speaker 1: dark matter has no other forces, then every time it
Speaker 1: gets to be a pretty dense clump is just going
Speaker 1: to turn into a dark matter black hole, because that's
Speaker 1: it's just gravity. But if dark matter does feel some
Speaker 1: other force, maybe some new force we've never seen before
Speaker 1: that only affects dark matter on dark matter interactions, then maybe,
Speaker 1: you know, clumping a bunch of the dark matter together
Speaker 1: could sp some sort of dark matter interaction which could
Speaker 1: release like dark photons. We're just wildly speculating here because
Speaker 1: we just really don't know what happens when dark matter
Speaker 1: bumps into dark matter, dark photons, and dark light. Yes, exactly,
Speaker 1: sounds like all good comic book characters. That's right. Today
Speaker 1: we've been exploring the connection between physics, philosophy and physics
Speaker 1: and comics books. Is it trifecta um? I think? You know,
Speaker 1: maybe that's where Ben's question came from. You know, like,
Speaker 1: you know, we know dark matter feels gravity, so why
Speaker 1: hasn't it clumped into dark matter black holes? You know,
Speaker 1: why is it still kind of diffused and and not
Speaker 1: um not more noticeable? You know? Does that mean that
Speaker 1: you know he's a alternative you mentioned are maybe probably true?
Speaker 1: You know that there are other forces or there are
Speaker 1: maybe other mechanisms going on inside of a dark matter Absolutely,
Speaker 1: I think a lot of physicists believe that there must
Speaker 1: be some other kind of force that dark matter feels,
Speaker 1: not just gravity, and the sort of complicated arguments for
Speaker 1: that based on what happened in the early universe and
Speaker 1: how some matter and dark matter turned back and forth
Speaker 1: into itself. We have indirect evidence of that happening, which
Speaker 1: suggests there must be some other force that dark matter feels,
Speaker 1: but we haven't figured that out yet at all. It's
Speaker 1: really it's very indirect arguments. But there is one thing
Speaker 1: that keeps dark matter from collapsing sort of quickly into
Speaker 1: a black hole, and that's our old friend rotation. Like,
Speaker 1: one thing that keeps the galaxy from collapsing into a
Speaker 1: black hole is that it's spinning, and so that keeps
Speaker 1: the stars from falling in just the way spinning the
Speaker 1: Earth spinning around the Sun keeps it from falling into
Speaker 1: the Sun. Right, it's an orbit. If you have a
Speaker 1: huge blob of dark matter and it's rotating, that rotation
Speaker 1: keeps it from collapsing gravitationally into a black hole. And
Speaker 1: so that's something that dark matter can do, even if
Speaker 1: even if it has no other interactions. But yeah, I
Speaker 1: think that it's totally possible that dark matter has formed
Speaker 1: really dense blobs inside our galaxy, and it's possible that
Speaker 1: there's new interactions doing weird stuff inside those dark matter
Speaker 1: objects that we have no idea about. But I think
Speaker 1: what you're saying maybe is that we we sort of
Speaker 1: haven't seen that yet, right, Like, if if we are
Speaker 1: surrounded by dark matter stars or dark matter you know,
Speaker 1: giant asteroids, you know, and one of them came through
Speaker 1: our Solar system, would we would notice it? Right, like
Speaker 1: we would notice all the other planets going whoa gravitation, Yes, exactly,
Speaker 1: that's the kind of thing we would notice for sure.
Speaker 1: I mean we noticed Omuamua, right, this tiny little rock
Speaker 1: coming through from from deep space and passing through our
Speaker 1: soul system with no gravitational interaction at all. That was
Speaker 1: but it was reflective. But imagine some really dense, heavy
Speaker 1: object that perturbed the path of the planets that we
Speaker 1: would definitely notice. Yeah, it would have to be pretty
Speaker 1: big though, because gravity is pretty weak, So like some
Speaker 1: random rock flying through the universe we wouldn't notice and
Speaker 1: have to be you know, like, it had to be
Speaker 1: a pretty significant objects. I'm not sure exactly how man,
Speaker 1: but some significant fraction in the mass of the Sun
Speaker 1: at the very least. Yeah, we would notice it, right,
Speaker 1: It would totally disrupt our solar system. Yeah, absolutely. But
Speaker 1: there could be a lot of these dark matter blobs
Speaker 1: out there and just none of them have passed through
Speaker 1: the Solar system because the galaxy is huge, right, and
Speaker 1: there's lots of blobs out there that that made a
Speaker 1: normal matter that don't pass through our solar system. Doesn't
Speaker 1: mean they're not out there. I mean, there could be
Speaker 1: a giant banana shaped massive dark matter out there that's
Speaker 1: waiting for us to slip on. That's right. You're gonna
Speaker 1: tie all the questions together. What if there's a banana
Speaker 1: shaped massive dark matter creating a Solar system sized black
Speaker 1: hole and we're in it, could we tell if there
Speaker 1: was another one that was identical? All right? Well, I
Speaker 1: guess that band's answer is that there could be dark
Speaker 1: matter stars and planets or things out there. We just
Speaker 1: we just can't see them yet. That's just don't have
Speaker 1: the the right glasses to see it more sharply, right,
Speaker 1: that's right. Yeah, um, And it's not clear that we
Speaker 1: ever will because we don't know what glasses to put on,
Speaker 1: or if there are glasses that you could even potentially
Speaker 1: theoretically put on to see this stuff. Well, obviously we
Speaker 1: just need dark glasses. I wear my sunglasses at night.
Speaker 1: I don't know about you. All right, Well, once again,
Speaker 1: thank you listeners for sending you as your questions. We
Speaker 1: love to interact with you online, and so please follow
Speaker 1: us and please tell your friends about this podcast. That's right.
Speaker 1: And if you're listening to us talk about something in
Speaker 1: physics and you have a question that pops into your mind,
Speaker 1: please share it with us. The reason we're doing this
Speaker 1: podcast is to clarify these things and explain them to you.
Speaker 1: And so there's something we've missed, we want to get
Speaker 1: on it. Yeah, and we'll answer it even if you
Speaker 1: are not our sons, unless you're on Instagram. In that case, sorry,
Speaker 1: in that case, you're out of luck. Do you have
Speaker 1: any sons on Instagram? You not aware of your trendy
Speaker 1: and like the rest of the universe, then maybe you
Speaker 1: should ask the question on Twitter. That's solid advice. Thanks
Speaker 1: for listening, hope you enjoyed it, Thanks for tuning in.
Speaker 1: If you still have a question after listening to all
Speaker 1: these explanations, please drop us a line. We'd love to
Speaker 1: hear from you. You can find us at Facebook, Twitter,
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Speaker 1: email us at Feedback at Daniel and Jorge dot com.
Speaker 1: Thanks for listening, and remember that Daniel and Jorge Explain
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