Latest / Daniel and Kelly’s Extraordinary Universe / Listener Questions 5

Transcript

Listener Questions 5 · Daniel and Kelly’s Extraordinary Universe

• 0:08
  Speaker 1: Hey, Daniel, do you get tired of answering questions? Oh? Never,
• 0:12
  Speaker 1: I love our listener questions. I just mean questions in general,
• 0:16
  Speaker 1: like about the universe, about your personal life, poor like
• 0:20
  Speaker 1: this question you're asking me now from your podcast host partner. No,
• 0:26
  Speaker 1: people ask me questions all the time, but it's fun
• 0:28
  Speaker 1: to answer them. You know, sometimes I wish I got
• 0:31
  Speaker 1: asked more science questions, you know, sometimes with questions are
• 0:34
  Speaker 1: more prosaic. But about your kids? And your kids constantly
• 0:37
  Speaker 1: pester you with science questions too, I wish they asked more.
• 0:41
  Speaker 1: You know. It's the occasional like what does the black
• 0:44
  Speaker 1: hole look like? But more often it's like can I
• 0:46
  Speaker 1: have more dessert? Or how could my sister just to
• 0:48
  Speaker 1: use the iPad more than I do? And the answer
• 0:52
  Speaker 1: is always the same. Nobody knows that we have no idea.
• 0:59
  Speaker 1: They're kind of six questions too, aren't they? Like? Um,
• 1:02
  Speaker 1: they're about time? Who gets more time on the iPad?
• 1:04
  Speaker 1: Or matter who gets more desserted? Exactly? And what about you?
• 1:10
  Speaker 1: Your kids ask you science questions? Uh? They do, yeah,
• 1:13
  Speaker 1: pretty pretty often. I think my kids, um like to
• 1:16
  Speaker 1: read and sometimes they kind of make connections in their
• 1:19
  Speaker 1: head and they ask me questions. And what do you
• 1:22
  Speaker 1: do when they ask you questions if you don't know
• 1:24
  Speaker 1: the answer. What do you mean you assume that I
• 1:26
  Speaker 1: don't know the answers. I often don't know the answer,
• 1:30
  Speaker 1: so I assume not everybody has all the answers. Sure, no,
• 1:33
  Speaker 1: Well I do my best. I guess um and maybe baby. Mainly,
• 1:39
  Speaker 1: I just tell them to send their questions into our
• 1:41
  Speaker 1: podcast so that you can answer them. That sounds good.
• 1:45
  Speaker 1: I'm glad to be your backup science parent. I mean,
• 1:47
  Speaker 1: what's the whole point of befriending as physicists if not
• 1:50
  Speaker 1: to get these questions answered? I knew, just would you
• 1:53
  Speaker 1: want to be friends with the physicists? I knew? I
• 1:56
  Speaker 1: felt used. Now I know why. Hi am Jorge. I'm
• 2:15
  Speaker 1: a cartoonist and the creator of PhD Comics. Hi I'm Daniel.
• 2:19
  Speaker 1: I'm a particle physicist and a backup science parent for
• 2:23
  Speaker 1: many people out there. And welcome to our podcast, Daniel
• 2:26
  Speaker 1: and Jorge Explain the Universe, a production of I Heart
• 2:30
  Speaker 1: Radio in which we take funny, weird, amazing, crazy things
• 2:34
  Speaker 1: about the universe and explain them to you so that
• 2:36
  Speaker 1: you can explain them to your kids or your parents
• 2:40
  Speaker 1: or just sit them down with with our podcast as
• 2:43
  Speaker 1: free babysitting. That's right. Yeah, so we we love answering questions,
• 2:48
  Speaker 1: right Daniel. Oh yeah, it's really fun because we can
• 2:50
  Speaker 1: think about the universe and we can talk about what's
• 2:52
  Speaker 1: exciting for us. But the most is interesting is answering
• 2:56
  Speaker 1: questions from listeners because it reveals what they understand and
• 2:59
  Speaker 1: what they own't and what they're wondering about, what all
• 3:02
  Speaker 1: those collective brains out there are cognating on. Yeah, so
• 3:05
  Speaker 1: if you don't know this already, we actually answer people's questions.
• 3:11
  Speaker 1: If we have an Instagram account, on Twitter account, on
• 3:13
  Speaker 1: Facebook account, and if you post a question, well, first
• 3:17
  Speaker 1: of all, follow us there, but if you post a question,
• 3:19
  Speaker 1: most likely Daniel will answer the question, right Daniel, or
• 3:23
  Speaker 1: at least maybe one of your regrets, that's right. No,
• 3:27
  Speaker 1: I'll answer questions via email or Twitter or Facebook. I'll
• 3:30
  Speaker 1: be honest, though, I don't use Instagram, so all those
• 3:33
  Speaker 1: people asking physics questions on Instagram are just questioning into
• 3:37
  Speaker 1: the void. Sorry, folks. The question is does anyone use
• 3:40
  Speaker 1: Instagram anymore? Now that I don't, I think the question
• 3:46
  Speaker 1: is who doesn't use Instagram these days? Just me, I guess,
• 3:50
  Speaker 1: I guess just physicists, you know. But it's wonderful. We
• 3:53
  Speaker 1: hear questions from all over the world, and sometimes there
• 3:57
  Speaker 1: are questions people just had in their minds they wanted
• 3:59
  Speaker 1: to know the answers to, and those are wonderful. But
• 4:01
  Speaker 1: also sometimes the questions are in reaction to something we
• 4:05
  Speaker 1: talked about on the show. You know, on the show,
• 4:07
  Speaker 1: we do our best to think, what's confusing about this?
• 4:11
  Speaker 1: How do we explain this? How do we make something clear?
• 4:13
  Speaker 1: But we never can completely succeed. So it's really nice
• 4:16
  Speaker 1: to have feedback when people say you said X, but
• 4:19
  Speaker 1: then I that made me wonder why, and that helps
• 4:22
  Speaker 1: us be more clear in the future. So please send
• 4:24
  Speaker 1: us feedback, send us questions, send us presents, send us gags,
• 4:28
  Speaker 1: send us whatever you have at Mostly you send us
• 4:32
  Speaker 1: money please, I mean, how much do you think podcasting? Me? Podcaster?
• 4:38
  Speaker 1: That's right? And sometimes people send us serious questions about
• 4:41
  Speaker 1: the universe. And then sometimes people send us silly questions. Yeah,
• 4:44
  Speaker 1: like what's been a silly question? All right, here's a
• 4:46
  Speaker 1: question we got on Twitter from Patrick Nouman. He says,
• 4:50
  Speaker 1: Dear Daniel and Jorge, I've got a question that really
• 4:54
  Speaker 1: want to get answered. How heavy would a blob or
• 4:57
  Speaker 1: banana bee of all of the photons in sun? And
• 5:00
  Speaker 1: how big would it be? Oh? Interesting, So you took
• 5:05
  Speaker 1: all the photons in the sun and somehow, what do
• 5:11
  Speaker 1: you think, transformed them into a banana or put them
• 5:14
  Speaker 1: in the space shaped them into a banana? What do
• 5:17
  Speaker 1: you think I actually started trying to work on this question.
• 5:20
  Speaker 1: At first, I thought, well, how many photons are in
• 5:23
  Speaker 1: the sun, right, like, is that a number? Um? You know,
• 5:26
  Speaker 1: and it's pretty tough. But it turns out you can
• 5:29
  Speaker 1: do a rough calculation and the sun creates ten to
• 5:32
  Speaker 1: the forty five photons per second. That's ten with that's
• 5:40
  Speaker 1: a lot of photons, a lot of like trillion, billy
• 5:44
  Speaker 1: busily but gillions, yes, exactly, billions and yeah, exactly. But
• 5:50
  Speaker 1: not all those photons escape the sun. You know, the
• 5:52
  Speaker 1: sun is a huge ball of plas and most of
• 5:54
  Speaker 1: the stuff that's made by the Sun is then just
• 5:56
  Speaker 1: reabsorbed by the Sun, and so only things that actually
• 5:59
  Speaker 1: penetrate leave the Sun and hate your eyeballs arrive here
• 6:02
  Speaker 1: on Earth. That's a tiny fraction what comes out of
• 6:05
  Speaker 1: the Sun. But anyway, let's say you had ten to
• 6:07
  Speaker 1: the forty five photons. Okay, that's a huge amount of
• 6:11
  Speaker 1: energy um. And then this question is interesting. He said,
• 6:14
  Speaker 1: how big would that be? Right? Like if you had
• 6:17
  Speaker 1: a pile of tending the forty five photons, right? How well?
• 6:21
  Speaker 1: How how how close together can you cram them in? Maybe? Yeah,
• 6:25
  Speaker 1: And that's really interesting because there's no limit on how
• 6:28
  Speaker 1: close you can cram photons together. That's not true ordinary
• 6:31
  Speaker 1: matter like electrons and other particles. These things are fermions,
• 6:36
  Speaker 1: and fermions are different from photons and other kind of
• 6:38
  Speaker 1: particles that we call bosons because fermions have to have
• 6:43
  Speaker 1: different quantum states. No two of them can be in
• 6:45
  Speaker 1: the same quantum state. They can literally be on top
• 6:49
  Speaker 1: of each other. That's impossible, that's right. They have to
• 6:51
  Speaker 1: have some difference, like you can have two electrons in
• 6:54
  Speaker 1: the same level of energy in a in an atom,
• 6:57
  Speaker 1: but then they have different have to have different spins
• 6:59
  Speaker 1: or something different about them, and so fer meons have
• 7:03
  Speaker 1: to be distinguishable, whereas bosons, these are particles with integer
• 7:07
  Speaker 1: spin like a photon. They can be right on top
• 7:10
  Speaker 1: of each other. They can be exactly the same place,
• 7:12
  Speaker 1: have the same momentum, had the same everything. I feel
• 7:14
  Speaker 1: like the silly question is is gotten a little seriously Yeah,
• 7:18
  Speaker 1: serious physics, yea, even silly questions reveals something interesting about
• 7:22
  Speaker 1: the universe. And so you can have ten to the
• 7:25
  Speaker 1: forty five photons on the head of a pin, basically
• 7:27
  Speaker 1: right or on top of each other. You're saying, yes, exactly,
• 7:30
  Speaker 1: all on top of each other in a tiny, tiny space.
• 7:33
  Speaker 1: So thank you Patrick for sending in that hilarious question.
• 7:36
  Speaker 1: It really made us think, and there really is some
• 7:38
  Speaker 1: physics in that question, even in silly questions. Well, we
• 7:41
  Speaker 1: do have three questions today from listeners, and so that
• 7:45
  Speaker 1: is the topic of today's podcast. To be on the podcast,
• 7:48
  Speaker 1: we'll be talking about listener questions five point five point
• 7:59
  Speaker 1: one five point one because we because we just answered
• 8:02
  Speaker 1: Patrick's questions, so we got to add a little that's right.
• 8:05
  Speaker 1: We're part way through this episode already. Um, that's right.
• 8:09
  Speaker 1: We'll be answering questions about electrons, about space, about stars,
• 8:12
  Speaker 1: about black holes, questions from far away, and questions from
• 8:16
  Speaker 1: surprisingly nearby. Yeah, and we might even know the answer
• 8:19
  Speaker 1: to some of these questions this time, and if we don't,
• 8:23
  Speaker 1: will speculate hilariously. All right, let's jump right into it. Daniel, there,
• 8:26
  Speaker 1: Our first question today is from this really pretty cool guy,
• 8:30
  Speaker 1: fun guy, one of maybe one of my favorite people,
• 8:32
  Speaker 1: has a great dad. Yeah, so this is a question
• 8:35
  Speaker 1: from Oliver from southern California. What if for whole solar
• 8:40
  Speaker 1: system is in a black hole and we don't notice? Wow,
• 8:44
  Speaker 1: that's a deep question. His voice sounds a little familiar
• 8:48
  Speaker 1: to me. Yeah. What a what a smart sounding little kid.
• 8:51
  Speaker 1: He sounds like he might grow up to be a cartoonist.
• 8:55
  Speaker 1: Well not if he's that smart, hopefully. So yeah, that's
• 8:58
  Speaker 1: my son who just asked that question in and he
• 9:01
  Speaker 1: just turned to me one day, Well, what happened? What?
• 9:03
  Speaker 1: He was reading our book? So we, Daniel and I
• 9:06
  Speaker 1: wrote a book called We Have No Idea, A Guide
• 9:08
  Speaker 1: to the Unknown Universe, available now in Amazon dot com.
• 9:11
  Speaker 1: And and you can verify it's been read by at
• 9:14
  Speaker 1: least one person since your son is reading it. That's right,
• 9:17
  Speaker 1: that's right. He's under age, but he still counts as
• 9:19
  Speaker 1: a person. He's nine years old, and so he's been
• 9:23
  Speaker 1: reading our book and I always kind of wonder how
• 9:25
  Speaker 1: much of it he's getting. You know, he's nine, he's
• 9:27
  Speaker 1: in third grade. Um, but he seems to be enjoying it,
• 9:31
  Speaker 1: and he keeps reading it, and so one day he
• 9:33
  Speaker 1: just turned to me and he asked me this question, right,
• 9:35
  Speaker 1: and what do you think is behind the question? What
• 9:38
  Speaker 1: do you think he's wondering? Explain the question to me?
• 9:40
  Speaker 1: Even explain my son do a deep dive. If I
• 9:44
  Speaker 1: knew that answer, Daniel, if I could explain my son,
• 9:47
  Speaker 1: my parenting experience would be so much. You know, I
• 9:50
  Speaker 1: thought it was really interesting. One part of his question says,
• 9:53
  Speaker 1: what if our whole solar system is in a black hole? Cool? Fascinating, Yeah,
• 9:58
  Speaker 1: But then he says, and we don't don't even notice?
• 10:03
  Speaker 1: Like I think that taps into you know, is the
• 10:06
  Speaker 1: universe different from how we expected? Is it possible that
• 10:10
  Speaker 1: we think we're living in universe X, but we're actually
• 10:12
  Speaker 1: living in universe? Why? You know? I think he was
• 10:15
  Speaker 1: probably kind of reading about black holes and he just
• 10:19
  Speaker 1: kind of wondered, like, what what if? What if we're
• 10:22
  Speaker 1: inside of a black hole? Is that possible? Like could
• 10:26
  Speaker 1: the universe? Or or like could could a solar system
• 10:30
  Speaker 1: exists inside of a black hole? And you know we
• 10:35
  Speaker 1: don't even know it? Yeah, And I think there's something
• 10:38
  Speaker 1: wonderful there about the feeling that maybe, you know, the
• 10:42
  Speaker 1: universe could be revealed to be totally different from what
• 10:44
  Speaker 1: you expected, because that's precisely happened a lot of times
• 10:47
  Speaker 1: in history, right, we thought, oh, the universe works this way. Nope,
• 10:51
  Speaker 1: it's totally different from what you imagined. And those are
• 10:54
  Speaker 1: the best moments in physics. So to hear your son
• 10:56
  Speaker 1: like sort of wondering if he's coming to that realization
• 10:59
  Speaker 1: him self, or wondering if this kind of realization is
• 11:02
  Speaker 1: around the corner, that's fantastic. He's been bitten by the
• 11:05
  Speaker 1: physics bug, so be careful. Oh no, he's gonna be
• 11:08
  Speaker 1: like Spider Man. Well that's only if he's bitten by
• 11:11
  Speaker 1: a radioactive physicist. Okay, radioactive. Well I grew up in
• 11:16
  Speaker 1: Los Alamos, so maybe I'm especially radioactive. But I'll do
• 11:18
  Speaker 1: my best not to not to about your son. Yeah,
• 11:21
  Speaker 1: but let's break it down. Um, it's interesting question. And
• 11:24
  Speaker 1: you know, something that's important to think about is sort
• 11:27
  Speaker 1: of the size of a black hole, like, could our
• 11:30
  Speaker 1: entire solar system fit into a black hole? Well? Right,
• 11:34
  Speaker 1: the size of a black hole is really we can
• 11:37
  Speaker 1: usually consider that to be the size of the event
• 11:39
  Speaker 1: horizon that's the point, right, the black style. Yeah, like
• 11:43
  Speaker 1: the point return. Look at a black hole, it would
• 11:46
  Speaker 1: look like a black sort of sphere, and so the
• 11:49
  Speaker 1: size of that sphere, that's the size of the black yeah. Yeah,
• 11:52
  Speaker 1: And if you go past that point, you can't escape, right.
• 11:55
  Speaker 1: And nobody knows what's inside of a black hole, but
• 11:58
  Speaker 1: we know how to calculate the size of the horizon.
• 12:00
  Speaker 1: It's determined just by the amount of stuff in the
• 12:03
  Speaker 1: black hole. So the more mass in the black hole,
• 12:06
  Speaker 1: the stronger the gravitational pull. The farther away it can
• 12:10
  Speaker 1: grab stuff and never let go, right, So the size
• 12:13
  Speaker 1: of the black hole is determined by its mass. So
• 12:15
  Speaker 1: how much stuff is in our solar system? Well, basically
• 12:18
  Speaker 1: the first approximation our solar system is just a soun.
• 12:22
  Speaker 1: Like the rest of the stuff in the solar system Jupiter, Mars,
• 12:25
  Speaker 1: me you hamsters, all that stuff is negligible. It's a
• 12:29
  Speaker 1: tiny fraction of the mass of the solar system. So
• 12:31
  Speaker 1: basically you can ask, like, if you had a black
• 12:34
  Speaker 1: hole with the mass of our Sun, how far away
• 12:38
  Speaker 1: would the event horizon B would it be out past
• 12:40
  Speaker 1: the edge of the black of the solar system? Is
• 12:43
  Speaker 1: it possible to fit a solar system in a black
• 12:45
  Speaker 1: hole that has the mass of our Sun. It's sort
• 12:48
  Speaker 1: of the way I interpret the question. So you're interpreting
• 12:51
  Speaker 1: the question as could our solar system be a black hole? Yeah? Exactly?
• 12:56
  Speaker 1: Could we be inside a black hole right now? Is
• 12:58
  Speaker 1: there enough room in a black hole with the mass
• 13:01
  Speaker 1: of the Sun to fit the entire solar system? So
• 13:05
  Speaker 1: could we be in a hole where the only thing
• 13:08
  Speaker 1: inside of it is our solar system? Yeah? Exactly exactly
• 13:11
  Speaker 1: is how you're interrupting the question. And the answer to
• 13:13
  Speaker 1: that is no, Because a black hole that has only
• 13:17
  Speaker 1: the mass of our sun, the event horizon would only
• 13:20
  Speaker 1: be three kilometers from the center of the Sun, and
• 13:24
  Speaker 1: so that definitely wouldn't be big enough to have the
• 13:27
  Speaker 1: whole solar system in it, because the solar system is
• 13:29
  Speaker 1: a lot more than three kilometers. It's one billion kilometers wide.
• 13:33
  Speaker 1: So we couldn't be in a black hole where the
• 13:35
  Speaker 1: only thing in it was our solar system. But is
• 13:38
  Speaker 1: it possible that we are that our solar system is
• 13:42
  Speaker 1: inside of somebody else's black hole? You know what I mean? Like,
• 13:45
  Speaker 1: maybe there's a black hole out there with a lot
• 13:48
  Speaker 1: of mass inside of it and we are just inside
• 13:51
  Speaker 1: of the event horizon of that black hole floating around. Yeah,
• 13:54
  Speaker 1: that's possible. Right, Let's let's consider that for a moment. So,
• 13:58
  Speaker 1: what if there's a really ends blobs somewhere else sort
• 14:02
  Speaker 1: of nearby, and that makes a black hole that's big
• 14:05
  Speaker 1: enough to encompass us, and we're inside that black hole
• 14:08
  Speaker 1: right right right, Well that's possible, but it's difficult to
• 14:13
  Speaker 1: imagine because such a huge mass would have a big
• 14:16
  Speaker 1: effect on us. You know, if there was a like
• 14:19
  Speaker 1: if there's a really big mass somewhere else inside our
• 14:21
  Speaker 1: Solar system next to the Sun, like an invisible huge
• 14:25
  Speaker 1: blob of dark matter, that that made their enough mass
• 14:28
  Speaker 1: so that the black hole was big enough, we would
• 14:30
  Speaker 1: definitely notice that that would affect the orbit of the planets.
• 14:33
  Speaker 1: What if there was another big mass kind of far
• 14:35
  Speaker 1: away but close enough that we were still inside the
• 14:39
  Speaker 1: event horizon, Well, you're talking about still really strong gravity.
• 14:43
  Speaker 1: So it's hard to imagine having some enormously powerful gravitational
• 14:47
  Speaker 1: attractor nearby and not having it disturbed like the orbits
• 14:51
  Speaker 1: of the planets or even just tossing of baseballs and
• 14:54
  Speaker 1: all sorts of stuff. So I think if you were
• 14:56
  Speaker 1: inside a black hole that was big enough to hold
• 14:59
  Speaker 1: a solar system, it would have to have a huge mass,
• 15:02
  Speaker 1: and that mass would definitely be noticeable. It would affect
• 15:05
  Speaker 1: the way things move on Earth, would it, though, Because
• 15:07
  Speaker 1: you know, like um so so our our solar system
• 15:11
  Speaker 1: is moving around a galaxy, right, Like, a galaxy has
• 15:14
  Speaker 1: a lot of mass and um and it's huge, and
• 15:17
  Speaker 1: there's a lot there's a huge black hole in the
• 15:19
  Speaker 1: center of the galaxy, but it's not really affecting us
• 15:23
  Speaker 1: in a local level, right, Like that gravity is kind
• 15:27
  Speaker 1: of spinning us around the galaxy, but it's not really
• 15:30
  Speaker 1: changing the orbits of the planets around the Sun, that's right. Yeah,
• 15:33
  Speaker 1: And that black hole in the center of the galaxy
• 15:35
  Speaker 1: is really massive and it's pretty big, but it's also
• 15:38
  Speaker 1: super duper duper duper far away. Right. Any black hole
• 15:42
  Speaker 1: that's either near enough to include us or far away
• 15:45
  Speaker 1: but huge enough to include us still would definitely affect
• 15:49
  Speaker 1: the gravitational poll But you know, I haven't done the calculation.
• 15:53
  Speaker 1: There is one configuration I imagine though. Imagine our entire
• 15:57
  Speaker 1: solar system and then it's surrounded by some enormously dense
• 16:01
  Speaker 1: sphere of material. Okay, if you're inside a sphere of material,
• 16:06
  Speaker 1: then the gravitational pull of that stuff doesn't affect you
• 16:09
  Speaker 1: at all, right, because it all balances out. Is enough
• 16:13
  Speaker 1: stuff on the left to balance the stuff on the right.
• 16:16
  Speaker 1: Just like that episode we talked about where you jump
• 16:17
  Speaker 1: inside the Earth. Once you get to the center of
• 16:20
  Speaker 1: the Earth, is no gravitational force from the stuff around you. Right, Well,
• 16:25
  Speaker 1: if you have to spear a super dense material surrounding
• 16:28
  Speaker 1: the Solar System, right, then that might be enough to
• 16:32
  Speaker 1: create a black hole, right that we would be inside of.
• 16:36
  Speaker 1: We wouldn't feel the gravitational force because we would be
• 16:39
  Speaker 1: inside all the stuff. It would be all around us. Yeah,
• 16:42
  Speaker 1: that's what I mean. Yeah, yeah, but they have to
• 16:44
  Speaker 1: be perfectly distributed, right. And the only reason that there's
• 16:48
  Speaker 1: one reason to think that's not the case, and that's
• 16:51
  Speaker 1: that we have sent stuff outside the Solar System, Like
• 16:54
  Speaker 1: we launched probes and they're floating off into space and
• 16:57
  Speaker 1: we're watching them and they haven't like banged up and
• 17:00
  Speaker 1: the wall of some hugely massive blob of stuff. But
• 17:03
  Speaker 1: what have you expand that idea even further to encompass
• 17:06
  Speaker 1: the whole observable universe. It is possible then that we
• 17:11
  Speaker 1: could be inside of a black hole. Yeah, yeah, it's
• 17:14
  Speaker 1: possible the entire observable universe is inside a black hole. Yes,
• 17:19
  Speaker 1: you can't rule that out. How do you feel about
• 17:21
  Speaker 1: saying that on a public record, Um, I wonder if
• 17:25
  Speaker 1: any of my colleagues are listening. No, I think it's awesome.
• 17:29
  Speaker 1: You would be surprised. I think it's awesome, And I
• 17:32
  Speaker 1: think sometimes these awesome questions come from the minds of children,
• 17:35
  Speaker 1: And that's why I hope that people are listening to
• 17:38
  Speaker 1: the podcast with their kids, because kids ask amazing questions
• 17:41
  Speaker 1: that make us think about things we otherwise would have
• 17:43
  Speaker 1: totally discarded that might actually be reality. Well, so that's
• 17:47
  Speaker 1: so that's the answer. The answer is that it is
• 17:49
  Speaker 1: totally possible that we are inside of a black hole
• 17:52
  Speaker 1: and not knowing. Yeah, but I think our whole universe
• 17:54
  Speaker 1: would have to be inside the black hole, not just
• 17:56
  Speaker 1: the solar system. But yeah, that's a pretty small conviat
• 17:58
  Speaker 1: for it for a yes answer to that question, isn't
• 18:00
  Speaker 1: that sort of a theory out there that were like
• 18:03
  Speaker 1: the whole universe are are inside the whole universe inside
• 18:06
  Speaker 1: of a black hole, and there are other black holes
• 18:08
  Speaker 1: and stuff. Like that or is that pretty fringe? I
• 18:10
  Speaker 1: think it is the theory out there, and it's pretty fringe,
• 18:13
  Speaker 1: But it's also totally possible, you know, like we really
• 18:16
  Speaker 1: just we don't know what's going on inside black holes?
• 18:19
  Speaker 1: Are there little universes in there? You know? The inside
• 18:22
  Speaker 1: of a black hole is totally disconnected from the space
• 18:26
  Speaker 1: that we live in, right, Like there's no way to
• 18:28
  Speaker 1: get from here to there, right, That's why that's how
• 18:30
  Speaker 1: a black hole works, even like can't escape it, not
• 18:33
  Speaker 1: because it's like slowing down the light as it tries
• 18:35
  Speaker 1: to leave, but because it's bent space in such a
• 18:38
  Speaker 1: way that there's just no path out, like just zooming
• 18:40
  Speaker 1: around inside the black hole. So in some ways you
• 18:43
  Speaker 1: can think of it as sort of like a different
• 18:45
  Speaker 1: universe disconnected from our our space, and so you can
• 18:49
  Speaker 1: imagine then anything that goes on in there. And uh,
• 18:52
  Speaker 1: when experiments can't constrain things, theorists minds tend to go wild,
• 18:56
  Speaker 1: and so they think about all sorts of crazy stuff
• 18:58
  Speaker 1: that could be inside there, insing bears or entire universes.
• 19:02
  Speaker 1: Crazy scientists and nine year old boys whom I grew
• 19:05
  Speaker 1: up to be crazy scientists. All right, Well, that's the
• 19:08
  Speaker 1: answered for Oliver's son of Jorge, and I'll let him
• 19:12
  Speaker 1: know if he has a good sum he stumped the physicists. Yeah,
• 19:17
  Speaker 1: it's a great question. If he was Icelandic, his last
• 19:20
  Speaker 1: name would be or Hasten exactly. All right, Well, we
• 19:26
  Speaker 1: have two other awesome questions that we are going to
• 19:29
  Speaker 1: answer about electron identity. I guess is that is that
• 19:33
  Speaker 1: we would be the right topic and also about dark
• 19:36
  Speaker 1: Matter stars, which sounds like a heavy battle band last
• 19:42
  Speaker 1: science fiction movie. So stay tuned, will be right back.
• 19:58
  Speaker 1: Al Right, we are back answering list are questions, and
• 20:01
  Speaker 1: so our next question comes from Yugi from the Netherlands,
• 20:04
  Speaker 1: and he is wondering if electrons have identity crises. That's right,
• 20:10
  Speaker 1: And this particular listener is something of a super fan,
• 20:13
  Speaker 1: writing to us on Twitter fairly often with insightful questions,
• 20:16
  Speaker 1: and he sent me this one and I thought, well
• 20:18
  Speaker 1: that's a good question, let's take it online, and so
• 20:22
  Speaker 1: here he is, Hi, Danielle and Jorge. My name is
• 20:25
  Speaker 1: Eugene Raudemake and I live in the Netherlands, hence the actions.
• 20:30
  Speaker 1: I'm a big fan of your morphous poticast cities, for
• 20:33
  Speaker 1: it makes me understand more of physics, and it makes
• 20:36
  Speaker 1: me think a lot about the universe in general. After
• 20:41
  Speaker 1: listening to your episode about quantum tunneling, the following question
• 20:45
  Speaker 1: came to my mind. If an electron tapt well say A,
• 20:50
  Speaker 1: suddenly appears in well B, how can physically still it's
• 20:54
  Speaker 1: actually this very same electron. I realized that I had
• 20:59
  Speaker 1: the both bowl empty swimming pool and the analogy in
• 21:02
  Speaker 1: my mind when the Christians sue appearance in my will.
• 21:07
  Speaker 1: Thanks for spending time answering my questions, all right, thank
• 21:12
  Speaker 1: you for saying this question, and also for being a
• 21:14
  Speaker 1: fan of the show. We really appreciate everyone listening out there. Yeah, exactly,
• 21:19
  Speaker 1: And uh, it's really a wonderful question, you know. To me,
• 21:21
  Speaker 1: it goes to the heart of like what are these particles?
• 21:24
  Speaker 1: What are we talking about? Um? But the way I
• 21:27
  Speaker 1: interpret his question is like, you haven't quite an electron
• 21:31
  Speaker 1: over here, and physics tells us the electron can then
• 21:34
  Speaker 1: later be over there. But his question is, how do
• 21:36
  Speaker 1: you know it's the same electron? Right, because we don't
• 21:40
  Speaker 1: have this sort of notion anymore of a classical path
• 21:43
  Speaker 1: that you can like watch a baseball fly through the
• 21:45
  Speaker 1: air and when a baseball, you know, when somebody hits
• 21:48
  Speaker 1: a home run, you watch it fly. You don't ask like,
• 21:51
  Speaker 1: is that the same baseball or is it suddenly swapped out?
• 21:54
  Speaker 1: But with quantum mechanical particles, because you can't observe them
• 21:57
  Speaker 1: all the way along the path, you just get these snapshots.
• 22:00
  Speaker 1: You can sort of wonder like, how do you know
• 22:02
  Speaker 1: that's the same electron? Maybe it's from another electron down
• 22:04
  Speaker 1: the street, right, it's just Tom or Harry or Mary
• 22:07
  Speaker 1: or Sally. I feel like the question is there such
• 22:09
  Speaker 1: a thing as an electron? Is there an electron? You
• 22:13
  Speaker 1: can say and follow it around and it has a
• 22:16
  Speaker 1: birth in a you know, journey, and then it maybe
• 22:19
  Speaker 1: answer at some point we can you follow an electron?
• 22:22
  Speaker 1: Or are we getting into identity politics now? So there's
• 22:25
  Speaker 1: electrons go back to where they came from physics. Yeah,
• 22:31
  Speaker 1: obviously we're not qualified to dive into those topics. You know,
• 22:36
  Speaker 1: well that's a it's a famous topic in physics, and
• 22:38
  Speaker 1: it's something that real physicists wonder and uh. In this
• 22:43
  Speaker 1: famous physicist, John Wheeler, he had this sort of moment
• 22:46
  Speaker 1: of insight and I don't know if he was smoking
• 22:48
  Speaker 1: banana peels or what. But he was wondering, like, why
• 22:51
  Speaker 1: do all electrons behave the same way? Like you drop
• 22:55
  Speaker 1: an electron in the in the circumstance, it's always going
• 22:57
  Speaker 1: to get repulsed in the same way. It's not like
• 22:59
  Speaker 1: this one's got a little bit more charge and that
• 23:01
  Speaker 1: one's got a little bit more mass. They're all identical.
• 23:04
  Speaker 1: They're not like scoops of ice cream, right, they all
• 23:06
  Speaker 1: have exactly the same properties. And he had this moment
• 23:09
  Speaker 1: of in said he thought, wait a second, maybe there
• 23:12
  Speaker 1: is just one electron. These are all the same electron.
• 23:18
  Speaker 1: What what do you mean, like the electrons in my
• 23:21
  Speaker 1: body and the ones in your body, they're all the same. Yes, yes,
• 23:24
  Speaker 1: sort of um, And I think I think that's actually
• 23:28
  Speaker 1: sort of the answer is that the electron is not
• 23:32
  Speaker 1: really um a particle that has an identity. It's sort
• 23:36
  Speaker 1: of like a state of mind or a state of matter, right,
• 23:40
  Speaker 1: because these days we don't think quantum mechanically about particles
• 23:44
  Speaker 1: as the fundamental basis of the universe. Instead we think
• 23:47
  Speaker 1: of fields, right, and particles are just excited states of
• 23:51
  Speaker 1: the field. It's sort of like when you look at
• 23:53
  Speaker 1: the ocean, you know, and you've tried to follow a wave. Right,
• 23:56
  Speaker 1: A wave is not the basic unit of the ocean.
• 23:59
  Speaker 1: It's the water. Right. The wave is just like, you know,
• 24:01
  Speaker 1: the ocean has got excited a little bit by the wind,
• 24:04
  Speaker 1: and it comes and it goes, and there's more waves
• 24:06
  Speaker 1: behind it. It's just it's just the motion of the ocean.
• 24:09
  Speaker 1: And that's right exactly. And so in that same way,
• 24:12
  Speaker 1: you can think of electrons. Not a's like, here's a
• 24:14
  Speaker 1: little chunk of matter, a little like piece of the
• 24:17
  Speaker 1: universe we're gonna follow around. But it's just like a
• 24:20
  Speaker 1: momentary excitation of this sort of hard to think about
• 24:24
  Speaker 1: thing called the electron field which fills the universe. And
• 24:28
  Speaker 1: when it gets a little bit of energy somewhere, you
• 24:30
  Speaker 1: call that an electron. It's not an object. It's kind
• 24:33
  Speaker 1: of a wiggle of an object. Yes, exactly, it's a
• 24:36
  Speaker 1: wiggle of an object. And you know, this goes back
• 24:39
  Speaker 1: to that other question we tried to answer. It's a photon,
• 24:42
  Speaker 1: a particle, or a wave, for example, And I think
• 24:44
  Speaker 1: I said on that podcast that it's sort of neither
• 24:47
  Speaker 1: and sort of both, and really it's something else weird
• 24:49
  Speaker 1: and fundamental that we just cannot understand by making analogies, right,
• 24:54
  Speaker 1: analogies from our macroscopic experience. Things that we're familiar with
• 24:57
  Speaker 1: just don't work because we've never seen anything like that before. Well,
• 25:01
  Speaker 1: it turns out you can apply the same idea as
• 25:03
  Speaker 1: to an electron also, right, an electron is both a
• 25:05
  Speaker 1: particle and a wave and both and neither and something
• 25:09
  Speaker 1: else totally weird. It's really just the excitation of a
• 25:13
  Speaker 1: quantum field. And and the reason, the reason actually that
• 25:16
  Speaker 1: we came up with quantum fields, the reason that this
• 25:19
  Speaker 1: whole development is progress, right and not just confusion, is
• 25:23
  Speaker 1: that it helps us think about the way particles are
• 25:26
  Speaker 1: created and destroyed. Because when electron is flying through um
• 25:30
  Speaker 1: the universe, it doesn't just sit around happily. It generates photons,
• 25:34
  Speaker 1: and those photons turned into electrons and positrons which turned
• 25:37
  Speaker 1: back into photons. Every electron is actually surrounded by like
• 25:40
  Speaker 1: a fuzz ball of virtual particles, photons and electrons and
• 25:43
  Speaker 1: things popping in out of the vacuum. What do you mean,
• 25:46
  Speaker 1: like an electron is not always an electron. It's constantly
• 25:51
  Speaker 1: kind of fuzzy and morphing and changing. Yes, exactly, it's
• 25:55
  Speaker 1: constantly morphing and changing and it's surrounded by a ball
• 25:59
  Speaker 1: of like almost an infinite number of low energy particles
• 26:03
  Speaker 1: that are being created and destroyed around it. Right, And
• 26:06
  Speaker 1: so we came up with this alternative mathematical formulation quantum
• 26:10
  Speaker 1: field theory, because it's really hard to follow the path
• 26:13
  Speaker 1: of an individual particle through this sort of probabilistic storm
• 26:17
  Speaker 1: of things that's happening, and it's much easier to just
• 26:20
  Speaker 1: think about the field that's generating all these particles. And
• 26:23
  Speaker 1: then a particle creation and destruction is much more natural
• 26:26
  Speaker 1: in quantum field theory than an old quantum mechanics where
• 26:29
  Speaker 1: we try to track follow an individual particle as if
• 26:32
  Speaker 1: it was a baseball. So we have to sort of
• 26:34
  Speaker 1: let go of this whole idea of particles having identities,
• 26:38
  Speaker 1: particles having paths, um and just think of them as
• 26:41
  Speaker 1: momentary oscillations in this field. Well, I think there's several
• 26:45
  Speaker 1: questions here, like, you know, maybe maybe you he was
• 26:50
  Speaker 1: also thinking of the wave analogy maybe, and so maybe
• 26:53
  Speaker 1: his question was, you know, just like you can follow
• 26:56
  Speaker 1: a wave in the ocean, you know, if you if
• 26:59
  Speaker 1: I make a ripple in the in the lake or something,
• 27:01
  Speaker 1: or you've even wave is made out into the ocean.
• 27:04
  Speaker 1: You can you can kind of follow that wave, right, like,
• 27:07
  Speaker 1: that's wave A. I'm gonna call it Sally, and you
• 27:12
  Speaker 1: can follow Sally as it moves across the Pacific, right,
• 27:16
  Speaker 1: you sort of can. But what if Sally looks exactly
• 27:18
  Speaker 1: like all the other waves, and there's billions of them,
• 27:22
  Speaker 1: and you look away, and then you look back and
• 27:25
  Speaker 1: you wonder which of those waves is Sally. That's the
• 27:30
  Speaker 1: situation where the one that um like, if I see
• 27:33
  Speaker 1: it at point A and I see at point B
• 27:35
  Speaker 1: one second later, well that's his question, right, the one
• 27:39
  Speaker 1: that's a point C another second later, basically right, could
• 27:42
  Speaker 1: be or could be there along the way got turned
• 27:44
  Speaker 1: into something else and then got turned back into a wave,
• 27:46
  Speaker 1: And is it the same wave then? But it almost
• 27:49
  Speaker 1: always is, isn't it? Like? Do electrons really just transformed
• 27:54
  Speaker 1: to something else constantly when we're not looking, constantly, even
• 27:58
  Speaker 1: while we're looking, electrons are constantly influx Yes, exactly. You
• 28:02
  Speaker 1: know there's that even the ones that in my body,
• 28:04
  Speaker 1: even the ones in your body, they're not special, sorry
• 28:06
  Speaker 1: to inform you. Um, you know, there's that ancient philosophical question, right,
• 28:11
  Speaker 1: there's some some ancient Greek ship, and every time it
• 28:14
  Speaker 1: comes into harbor that it's lost a piece and they
• 28:16
  Speaker 1: repair it, and then after five years there are no
• 28:19
  Speaker 1: pieces of the original ship, and they wonder, like, is
• 28:21
  Speaker 1: it still that same ship? You know, if it's made
• 28:24
  Speaker 1: out of all new pieces? Um, And it's sort of
• 28:26
  Speaker 1: that question, but it's the particle version of that question.
• 28:31
  Speaker 1: And uh, wait, what if it rides the same wave
• 28:33
  Speaker 1: though that the Greeks mine? Yeah, exactly, And so I'd
• 28:42
  Speaker 1: say in this in the same way, there there is
• 28:44
  Speaker 1: really no particle identity. Um, I don't I don't know
• 28:47
  Speaker 1: that I've smoked enough. But An appeals to say they're
• 28:48
  Speaker 1: all the same electron But I think sort of what
• 28:51
  Speaker 1: he's saying is that they're all manifestations of the same field. Right,
• 28:55
  Speaker 1: there's really just one electron field and it appears and
• 28:59
  Speaker 1: lots of different places is in the universe. But then
• 29:01
  Speaker 1: what's really going on? Because you know, I feel pretty consistent,
• 29:05
  Speaker 1: you know, like I am this way sort of now
• 29:08
  Speaker 1: and and I'm sort of the same way a second ago.
• 29:12
  Speaker 1: I think that's my perception. Are you saying that, you
• 29:16
  Speaker 1: know I could have changed into something totally different between
• 29:18
  Speaker 1: now and the next second, that I am conscious about, yes,
• 29:22
  Speaker 1: But the jorhan nous is not about the stuff that
• 29:25
  Speaker 1: you're made up of, but the arrangement of those particles. Right,
• 29:29
  Speaker 1: just like that ship is not about the pieces of
• 29:32
  Speaker 1: wood that went into it, but how they're put together
• 29:34
  Speaker 1: and what it's doing, and you know how it spends
• 29:36
  Speaker 1: its time. And so in the same way, you are
• 29:39
  Speaker 1: a constantly frothing mass of quantum mechanical particles. But that's
• 29:42
  Speaker 1: not what makes you you. What makes you use the
• 29:45
  Speaker 1: way they're arranged and the way they live their life. Well,
• 29:47
  Speaker 1: I am a constant frothing mass of something. Sure, it's
• 29:52
  Speaker 1: a really hard question. And you know, this is a
• 29:55
  Speaker 1: question which is definitely on the philosophy side of the threshold.
• 29:59
  Speaker 1: And something I love about physics is that it bumps
• 30:02
  Speaker 1: up against philosophy so often because they're deep consequences to
• 30:07
  Speaker 1: the answers of physics questions. And so I've always been
• 30:10
  Speaker 1: really interested in in the philosophical implications of particle physics. Um,
• 30:15
  Speaker 1: but I have to say it's not something that most
• 30:17
  Speaker 1: of us, most of us particle physicists, are actually qualified
• 30:21
  Speaker 1: to talk about, even though we do pontificate long windedly
• 30:24
  Speaker 1: on it. Oh, I see. It's it's one of these
• 30:26
  Speaker 1: questions that the answer is kind of like it depends
• 30:29
  Speaker 1: on what the definition of is isuly I have to
• 30:34
  Speaker 1: go there, but I think it applies in this case.
• 30:38
  Speaker 1: Yeah right, It's sort of like it depends on what
• 30:41
  Speaker 1: you mean by having an identity or being the same
• 30:43
  Speaker 1: electron exactly, you can dig into that forever and smoke
• 30:47
  Speaker 1: manin appeals and not necessarily make any progress exactly. Yeah,
• 30:51
  Speaker 1: or cigars. But it's a really fun question, So thank
• 30:54
  Speaker 1: you for asking it. Yeah, well, what's the What would
• 30:56
  Speaker 1: you say is the answer? Then? Do electrons have an
• 30:59
  Speaker 1: identity or can you have the same electro on? The
• 31:02
  Speaker 1: answer seems to be I would say no. I would
• 31:04
  Speaker 1: say identity is a macroscopic quality that we like to
• 31:08
  Speaker 1: attribute to things because we're used to it, because we're
• 31:10
  Speaker 1: familiar with it. We expected to tom. We expect also
• 31:14
  Speaker 1: tiny particles to have it, but they don't and and
• 31:17
  Speaker 1: so I think it's odd and uh, and it's it
• 31:20
  Speaker 1: tells us more about how we think than about how
• 31:22
  Speaker 1: the universe works. So you're saying, at the microscopic level,
• 31:26
  Speaker 1: at the individual electron level, these things we can apply
• 31:30
  Speaker 1: because things are just constantly changing and frothing, and yeah, exactly,
• 31:35
  Speaker 1: I don't think it has any meaning at the microscopic level.
• 31:37
  Speaker 1: All right, well, thank you hear you from the Netherlands
• 31:40
  Speaker 1: for that question. Please keep listening. I hope he answered
• 31:43
  Speaker 1: your question. Answer your question to your satisfaction. Uh So
• 31:47
  Speaker 1: we have one more question, and this one comes from
• 31:50
  Speaker 1: Mexico or Mexico about dark matter stars. But first let's
• 31:54
  Speaker 1: take a quick break. Al right. Our last question of
• 32:10
  Speaker 1: today comes from ben who is sending his question from Mexico,
• 32:15
  Speaker 1: and he has a question about dark matter stars. Hi,
• 32:18
  Speaker 1: Daniel lane J. This is Benjamin from Mexico, and I
• 32:22
  Speaker 1: was wondering, if the dark matter has all these gravitational
• 32:26
  Speaker 1: properties as the regular matter, why have an astrophysicists discovered
• 32:31
  Speaker 1: yet a big celestial body made of dark matter, like
• 32:35
  Speaker 1: a dark matter star or something big that we can
• 32:38
  Speaker 1: indirectly now it's there. Thank you. All right, that's a
• 32:42
  Speaker 1: pretty cool question. Where aren't there dark stars besides a
• 32:49
  Speaker 1: in comic books? I think that's a comic book villain.
• 32:53
  Speaker 1: Exactly it should be, yeah, exactly. Um No, it's an
• 32:56
  Speaker 1: awesome question, and the way I interpret it is that
• 33:00
  Speaker 1: he's wondering why can't we tell that dark matter is there?
• 33:03
  Speaker 1: Why it hasn't dark matter coalesced into some sort of
• 33:06
  Speaker 1: object that we could then pinpoint, Because I think he
• 33:09
  Speaker 1: maybe is frustrated at the sort of diffusiveness of dark matter.
• 33:13
  Speaker 1: We know it's there, we know it's sort of everywhere,
• 33:16
  Speaker 1: but we can't seem to say exactly where it is
• 33:18
  Speaker 1: and why not? Is that how you interpret the question?
• 33:20
  Speaker 1: Why does it stay so fuzzy? Yeah? Yeah, exactly. And
• 33:25
  Speaker 1: I think that the key thing to understand here is
• 33:27
  Speaker 1: remember that gravity is really really weak, and it's the
• 33:30
  Speaker 1: only way we can see dark matter so far. The
• 33:32
  Speaker 1: only way we can feel it is through its gravity,
• 33:35
  Speaker 1: and and so it takes a huge amount of stuff
• 33:38
  Speaker 1: to notice something just from gravity. Remember, the gravity is
• 33:41
  Speaker 1: so weak that you can feel the Earth's gravity, but
• 33:44
  Speaker 1: you can't feel the gravity of your car or your house,
• 33:47
  Speaker 1: even though there is a gravitational pull there, it takes
• 33:50
  Speaker 1: some huge body to even feel it. Right, Well, maybe
• 33:53
  Speaker 1: we should recap and a little bit about dark matter. Right,
• 33:57
  Speaker 1: So we know that dark matter feels gravity, right, that's
• 34:01
  Speaker 1: how we sort of know it's there because it's pulling
• 34:03
  Speaker 1: us around the galaxy. But it doesn't feel electromagnetic forces,
• 34:07
  Speaker 1: which means we can't see it or touch it. Right,
• 34:10
  Speaker 1: that's right exactly. It doesn't give off light, it doesn't
• 34:13
  Speaker 1: reflect light. We can't see it using any of those
• 34:15
  Speaker 1: normal methods that we usually used to see stuff, right,
• 34:19
  Speaker 1: But it does feel gravity, and so I think maybe
• 34:22
  Speaker 1: Ben's question is, if dark matter feels gravity, why hasn't
• 34:26
  Speaker 1: it clumped together out in space because it's attracted to itself, right,
• 34:31
  Speaker 1: isn't it attracted to itself? Dark matter is attracted to
• 34:33
  Speaker 1: itself by gravity, absolutely yes, and it has clumped together. Right,
• 34:38
  Speaker 1: dark matter is not evenly spread throughout the universe. Dark
• 34:42
  Speaker 1: matter has clumped together thanks to gravity, and it's formed
• 34:45
  Speaker 1: these big blobs. And it's, in fact only because dark
• 34:49
  Speaker 1: matter has clumped together to make these blobs that we
• 34:53
  Speaker 1: have galaxies and we are alive, because without dark matters
• 34:57
  Speaker 1: gravitational pull, there wouldn't be enough gravity to hold the
• 35:00
  Speaker 1: galaxies together. And we've done simulations and seeing that in
• 35:04
  Speaker 1: universities without dark matter, it takes a lot longer for
• 35:07
  Speaker 1: gravity to pull all this luminous stuff together to make
• 35:11
  Speaker 1: stars and planets and galaxies. So dark matter does make
• 35:15
  Speaker 1: um structure, It does make objects. But those objects are
• 35:18
  Speaker 1: sort of big and diffuse, and and they're sort of
• 35:21
  Speaker 1: the size of the galaxy. And and you might ask, well,
• 35:24
  Speaker 1: how do we know that the dark matter inside the
• 35:27
  Speaker 1: galaxy hasn't also clumped together to make you know, star
• 35:31
  Speaker 1: size stuff or planet sized stuff the way normal matter has, right,
• 35:35
  Speaker 1: And And we don't know the answer to that, right,
• 35:38
  Speaker 1: And the reason we don't know is because we can't
• 35:40
  Speaker 1: see dark matter and enough to tail Like, it's totally
• 35:43
  Speaker 1: possible that the distribution of dark matter in the galaxy
• 35:47
  Speaker 1: is either a totally smoothly spread out right, be sort
• 35:52
  Speaker 1: of like a cloud. Now we know it's denser towards
• 35:55
  Speaker 1: the center and less dense towards the outside, but it
• 35:59
  Speaker 1: could still be like a like a big cloud, right,
• 36:01
  Speaker 1: Or it could be that their structure that it's clumped
• 36:04
  Speaker 1: together to make, you know, a bunch of dense points,
• 36:07
  Speaker 1: just the way normal matter has. So there could be
• 36:10
  Speaker 1: dark matter stars or dark matter planets exactly, but the
• 36:15
  Speaker 1: only way to see them would be through gravity. And
• 36:17
  Speaker 1: it's really hard to see a gravity from like one
• 36:20
  Speaker 1: planet or the gravity from one star, right unless it's
• 36:24
  Speaker 1: really close by. Like if there were dark matter stars
• 36:27
  Speaker 1: and a dark matter star passed near our solar system,
• 36:31
  Speaker 1: then we could detect it the way we detect black
• 36:34
  Speaker 1: holes right there. Black holes are invisible. We detect them
• 36:37
  Speaker 1: from their gravity. Sometimes we detect black holes because of
• 36:40
  Speaker 1: the X rays that are produced from compressed gas nearby.
• 36:43
  Speaker 1: But a lot of black holes we see through their gravity.
• 36:46
  Speaker 1: But you need to be a pretty big black hole
• 36:48
  Speaker 1: to detect its gravity from far away or to see
• 36:51
  Speaker 1: its gravitational effect. Are nearby stuff, right, And in fact,
• 36:55
  Speaker 1: there are a few of these things we found, and
• 36:58
  Speaker 1: they have a pretty silly name. You ready for it
• 37:00
  Speaker 1: always physics really names. Yeah, they're back a long time
• 37:05
  Speaker 1: ago before we knew whether dark matter was the thing.
• 37:07
  Speaker 1: People were wondering if they were just big clumps of
• 37:09
  Speaker 1: normal matter there was sort of hidden out there, and
• 37:12
  Speaker 1: they gave them this name, massive compact halo objects, and
• 37:17
  Speaker 1: the acronym for that is m A C h O. Right,
• 37:20
  Speaker 1: so mach of these not nachos. Nachos are a totally
• 37:23
  Speaker 1: different thing. These are MACHOs. And so that's not physicists
• 37:28
  Speaker 1: over compensating for anything, not at all. No, And so
• 37:31
  Speaker 1: people went out there and looking for these things, like
• 37:33
  Speaker 1: can we find dark blobs out there, dark condensed blobs
• 37:38
  Speaker 1: out there that might be responsible for all the missing mass, right,
• 37:42
  Speaker 1: And they did find a bunch of not nearly enough
• 37:44
  Speaker 1: to account for all the dark matter, but they found
• 37:46
  Speaker 1: a bunch of them. They would find them like eclipsing
• 37:49
  Speaker 1: stars or bending the path of other objects. Um. And
• 37:53
  Speaker 1: so we know that there are dark objects out there.
• 37:55
  Speaker 1: Some of them could be dark matter, right, Some of
• 37:58
  Speaker 1: them could be so totally possible that dark matter has
• 38:02
  Speaker 1: clumped these objects together. We just don't have the gravitational
• 38:05
  Speaker 1: sensitivity to see them because they're too small. Essentially, in
• 38:09
  Speaker 1: gravity is so weak, Like our ability to notice or
• 38:14
  Speaker 1: feel or see dark matter is not at the planet
• 38:18
  Speaker 1: or at the star level. It's only at sort of
• 38:20
  Speaker 1: the galaxy level, yeah, exactly a little bit less than
• 38:23
  Speaker 1: the galaxy. We can we can get some sense of
• 38:25
  Speaker 1: where they are based on how rotations vary as a
• 38:29
  Speaker 1: function of the radius from the center of the galaxy.
• 38:31
  Speaker 1: But roughly yet much more the galaxy level than the
• 38:33
  Speaker 1: star level. But but it's fun to think about, like
• 38:37
  Speaker 1: imagine what would happen. What would happen if you had
• 38:39
  Speaker 1: a huge blob of dark matter and it coalesced into
• 38:42
  Speaker 1: sort of a tight blob, like would it make a
• 38:44
  Speaker 1: star like planet? You know? And we when we say
• 38:47
  Speaker 1: a star, we sort of mean something that's big enough,
• 38:49
  Speaker 1: has enough gravity that it's pushed the stuff together that
• 38:53
  Speaker 1: begins to fuse and release energy, right, And so another
• 38:56
  Speaker 1: interesting question is like, what would happen if you squeeze
• 38:59
  Speaker 1: that much dark matter together? What interesting things happen, like, um,
• 39:04
  Speaker 1: you know, elements fusing and releasing photons and things like that. Well,
• 39:08
  Speaker 1: we don't know, but we know it's not made of elements, right,
• 39:10
  Speaker 1: It's not made of atoms. It's made of some some
• 39:12
  Speaker 1: other kind of matter. And the only interaction we know
• 39:15
  Speaker 1: it has is gravity. So as far as we know,
• 39:18
  Speaker 1: it would just squeeze and squeeze and squeeze and squeeze,
• 39:21
  Speaker 1: and there's no repulsion. Right. The thing that keeps a
• 39:24
  Speaker 1: star or a planet from immediately becoming a black hole
• 39:27
  Speaker 1: are the other forces. It feels like electromagnetism, which and
• 39:31
  Speaker 1: the strong force which fuel fusion, right, which keeps a
• 39:34
  Speaker 1: star exploding. It keeps it from collapsing immediately. So if
• 39:38
  Speaker 1: dark matter has no other forces, then every time it
• 39:41
  Speaker 1: gets to be a pretty dense clump is just going
• 39:43
  Speaker 1: to turn into a dark matter black hole, because that's
• 39:46
  Speaker 1: it's just gravity. But if dark matter does feel some
• 39:50
  Speaker 1: other force, maybe some new force we've never seen before
• 39:53
  Speaker 1: that only affects dark matter on dark matter interactions, then maybe,
• 39:57
  Speaker 1: you know, clumping a bunch of the dark matter together
• 39:59
  Speaker 1: could sp some sort of dark matter interaction which could
• 40:02
  Speaker 1: release like dark photons. We're just wildly speculating here because
• 40:07
  Speaker 1: we just really don't know what happens when dark matter
• 40:09
  Speaker 1: bumps into dark matter, dark photons, and dark light. Yes, exactly,
• 40:14
  Speaker 1: sounds like all good comic book characters. That's right. Today
• 40:19
  Speaker 1: we've been exploring the connection between physics, philosophy and physics
• 40:22
  Speaker 1: and comics books. Is it trifecta um? I think? You know,
• 40:25
  Speaker 1: maybe that's where Ben's question came from. You know, like,
• 40:29
  Speaker 1: you know, we know dark matter feels gravity, so why
• 40:32
  Speaker 1: hasn't it clumped into dark matter black holes? You know,
• 40:36
  Speaker 1: why is it still kind of diffused and and not
• 40:39
  Speaker 1: um not more noticeable? You know? Does that mean that
• 40:44
  Speaker 1: you know he's a alternative you mentioned are maybe probably true?
• 40:49
  Speaker 1: You know that there are other forces or there are
• 40:52
  Speaker 1: maybe other mechanisms going on inside of a dark matter Absolutely,
• 40:57
  Speaker 1: I think a lot of physicists believe that there must
• 40:59
  Speaker 1: be some other kind of force that dark matter feels,
• 41:02
  Speaker 1: not just gravity, and the sort of complicated arguments for
• 41:05
  Speaker 1: that based on what happened in the early universe and
• 41:07
  Speaker 1: how some matter and dark matter turned back and forth
• 41:10
  Speaker 1: into itself. We have indirect evidence of that happening, which
• 41:13
  Speaker 1: suggests there must be some other force that dark matter feels,
• 41:16
  Speaker 1: but we haven't figured that out yet at all. It's
• 41:18
  Speaker 1: really it's very indirect arguments. But there is one thing
• 41:22
  Speaker 1: that keeps dark matter from collapsing sort of quickly into
• 41:26
  Speaker 1: a black hole, and that's our old friend rotation. Like,
• 41:29
  Speaker 1: one thing that keeps the galaxy from collapsing into a
• 41:32
  Speaker 1: black hole is that it's spinning, and so that keeps
• 41:35
  Speaker 1: the stars from falling in just the way spinning the
• 41:38
  Speaker 1: Earth spinning around the Sun keeps it from falling into
• 41:40
  Speaker 1: the Sun. Right, it's an orbit. If you have a
• 41:43
  Speaker 1: huge blob of dark matter and it's rotating, that rotation
• 41:46
  Speaker 1: keeps it from collapsing gravitationally into a black hole. And
• 41:50
  Speaker 1: so that's something that dark matter can do, even if
• 41:53
  Speaker 1: even if it has no other interactions. But yeah, I
• 41:56
  Speaker 1: think that it's totally possible that dark matter has formed
• 41:59
  Speaker 1: really dense blobs inside our galaxy, and it's possible that
• 42:03
  Speaker 1: there's new interactions doing weird stuff inside those dark matter
• 42:06
  Speaker 1: objects that we have no idea about. But I think
• 42:09
  Speaker 1: what you're saying maybe is that we we sort of
• 42:11
  Speaker 1: haven't seen that yet, right, Like, if if we are
• 42:14
  Speaker 1: surrounded by dark matter stars or dark matter you know,
• 42:18
  Speaker 1: giant asteroids, you know, and one of them came through
• 42:21
  Speaker 1: our Solar system, would we would notice it? Right, like
• 42:24
  Speaker 1: we would notice all the other planets going whoa gravitation, Yes, exactly,
• 42:29
  Speaker 1: that's the kind of thing we would notice for sure.
• 42:31
  Speaker 1: I mean we noticed Omuamua, right, this tiny little rock
• 42:34
  Speaker 1: coming through from from deep space and passing through our
• 42:36
  Speaker 1: soul system with no gravitational interaction at all. That was
• 42:40
  Speaker 1: but it was reflective. But imagine some really dense, heavy
• 42:43
  Speaker 1: object that perturbed the path of the planets that we
• 42:46
  Speaker 1: would definitely notice. Yeah, it would have to be pretty
• 42:48
  Speaker 1: big though, because gravity is pretty weak, So like some
• 42:52
  Speaker 1: random rock flying through the universe we wouldn't notice and
• 42:55
  Speaker 1: have to be you know, like, it had to be
• 42:57
  Speaker 1: a pretty significant objects. I'm not sure exactly how man,
• 43:00
  Speaker 1: but some significant fraction in the mass of the Sun
• 43:02
  Speaker 1: at the very least. Yeah, we would notice it, right,
• 43:05
  Speaker 1: It would totally disrupt our solar system. Yeah, absolutely. But
• 43:09
  Speaker 1: there could be a lot of these dark matter blobs
• 43:12
  Speaker 1: out there and just none of them have passed through
• 43:14
  Speaker 1: the Solar system because the galaxy is huge, right, and
• 43:18
  Speaker 1: there's lots of blobs out there that that made a
• 43:20
  Speaker 1: normal matter that don't pass through our solar system. Doesn't
• 43:23
  Speaker 1: mean they're not out there. I mean, there could be
• 43:25
  Speaker 1: a giant banana shaped massive dark matter out there that's
• 43:31
  Speaker 1: waiting for us to slip on. That's right. You're gonna
• 43:33
  Speaker 1: tie all the questions together. What if there's a banana
• 43:36
  Speaker 1: shaped massive dark matter creating a Solar system sized black
• 43:40
  Speaker 1: hole and we're in it, could we tell if there
• 43:43
  Speaker 1: was another one that was identical? All right? Well, I
• 43:46
  Speaker 1: guess that band's answer is that there could be dark
• 43:49
  Speaker 1: matter stars and planets or things out there. We just
• 43:52
  Speaker 1: we just can't see them yet. That's just don't have
• 43:55
  Speaker 1: the the right glasses to see it more sharply, right,
• 44:00
  Speaker 1: that's right. Yeah, um, And it's not clear that we
• 44:03
  Speaker 1: ever will because we don't know what glasses to put on,
• 44:05
  Speaker 1: or if there are glasses that you could even potentially
• 44:09
  Speaker 1: theoretically put on to see this stuff. Well, obviously we
• 44:11
  Speaker 1: just need dark glasses. I wear my sunglasses at night.
• 44:15
  Speaker 1: I don't know about you. All right, Well, once again,
• 44:18
  Speaker 1: thank you listeners for sending you as your questions. We
• 44:21
  Speaker 1: love to interact with you online, and so please follow
• 44:24
  Speaker 1: us and please tell your friends about this podcast. That's right.
• 44:27
  Speaker 1: And if you're listening to us talk about something in
• 44:29
  Speaker 1: physics and you have a question that pops into your mind,
• 44:32
  Speaker 1: please share it with us. The reason we're doing this
• 44:35
  Speaker 1: podcast is to clarify these things and explain them to you.
• 44:38
  Speaker 1: And so there's something we've missed, we want to get
• 44:40
  Speaker 1: on it. Yeah, and we'll answer it even if you
• 44:43
  Speaker 1: are not our sons, unless you're on Instagram. In that case, sorry,
• 44:47
  Speaker 1: in that case, you're out of luck. Do you have
• 44:51
  Speaker 1: any sons on Instagram? You not aware of your trendy
• 44:53
  Speaker 1: and like the rest of the universe, then maybe you
• 44:56
  Speaker 1: should ask the question on Twitter. That's solid advice. Thanks
• 45:00
  Speaker 1: for listening, hope you enjoyed it, Thanks for tuning in.
• 45:13
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• 45:16
  Speaker 1: these explanations, please drop us a line. We'd love to
• 45:19
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• 45:25
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• 45:29
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• 45:32
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