Latest / Daniel and Kelly’s Extraordinary Universe / Listener Questions 63: Hawking radiation, mass, and anti-strings

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Listener Questions 63: Hawking radiation, mass, and anti-strings · Daniel and Kelly’s Extraordinary Universe

0:08
Speaker 1: Hey, Daniel, if you could throw anything into a black hole,
0:12
Speaker 1: what would it be?
0:15
Speaker 2: I guess it'd be something I don't ever want to
0:17
Speaker 2: see again, Like a bunch of white chocolate.
0:21
Speaker 1: You know that doesn't get rid of the concept of
0:23
Speaker 1: white chocolate. People can still make more.
0:25
Speaker 2: And I'll keep throwing it in the black hole until
0:27
Speaker 2: they learn.
0:28
Speaker 1: But if you throw a white chocolate into a black hole,
0:31
Speaker 1: does it make it a white hole?
0:33
Speaker 2: If it eats matter, it's a black hole. A white
0:36
Speaker 2: hole would be making matter.
0:37
Speaker 1: So if you ever see a white hole out there
0:39
Speaker 1: in space, it's it's basically a white chocolate fountain.
0:42
Speaker 2: If there's somebody on the other side throwing all their
0:45
Speaker 2: white chocolate into a black hole, then yeah.
0:48
Speaker 1: Or does a dark chocolate get turned into white chocolate
0:50
Speaker 1: on the other side?
0:52
Speaker 2: What a cosmic tragedy that would be.
0:54
Speaker 1: What if you're in like the five percent of the
0:56
Speaker 1: universe that doesn't like white chocolate, What if it's cosmically
0:59
Speaker 1: loved except for a certain household in Irvine, California.
1:04
Speaker 2: I don't want to meet those aliens.
1:20
Speaker 1: Hi, I am morehy Man cartoonas and the author of
1:22
Speaker 1: Oliver's Great Big Universe.
1:24
Speaker 2: Hi, I'm Daniel, I'm a particle physicist and a professor
1:27
Speaker 2: at UC Irvine, And yes, I'll meet the white chocolate aliens.
1:31
Speaker 1: Aliens are made out of white chocolate, or they like
1:33
Speaker 1: white chocolate.
1:34
Speaker 2: If they're made out of white chocolate, I'll feel so
1:36
Speaker 2: sorry for them that I'll definitely meet them just out
1:38
Speaker 2: of pain.
1:40
Speaker 1: Well, they probably feel really safe around you because they
1:43
Speaker 1: know you won't eat them.
1:44
Speaker 2: That's true exactly, But they might melt in the sun.
1:47
Speaker 2: You know, that stuff is just not really very substantial.
1:51
Speaker 1: They need like sunshields or something. But anyways, welcome to
1:54
Speaker 1: our podcast, Daniel and Jorge Explain the Universe, a production
1:57
Speaker 1: of iHeartRadio.
1:58
Speaker 2: In which we take a deep look at both sides
2:00
Speaker 2: of the universe, the light matter, the dark matter, the
2:03
Speaker 2: white chocolate, the dark chocolate, the stuff that we're curious
2:06
Speaker 2: about and the stuff that you are curious about. We
2:09
Speaker 2: think that everything out there in the universe is a
2:11
Speaker 2: delicious mystery, and it deserves to have a bite taken
2:14
Speaker 2: out of it.
2:14
Speaker 1: That's right. We try to delve into the deep, dark
2:17
Speaker 1: mysteries of the universe as well as its shiny bright facts,
2:21
Speaker 1: the things that scientists and work hard over many years
2:23
Speaker 1: to discover and figure out how it all works.
2:26
Speaker 2: And one of the goals of the podcast is to
2:28
Speaker 2: take you along on that journey. Puzzling out the nature
2:31
Speaker 2: of the universe is not just something professional scientists should do.
2:34
Speaker 2: It's something everybody should be thinking about. We should all
2:37
Speaker 2: be thinking like a physicist, even if we're not thinking
2:39
Speaker 2: about physics problems. But those physics problems are fascinating and
2:43
Speaker 2: are deep and are consequential. Where do the universe come from?
2:46
Speaker 2: How does it all work? How will it all end?
2:48
Speaker 2: Where is our place in it? All? These things are
2:51
Speaker 2: questions that everybody has, and we hope to work together
2:54
Speaker 2: to find the answer. And that means you should also
2:57
Speaker 2: be asking questions.
2:59
Speaker 1: Yeah, because about the universe are all around us. They
3:02
Speaker 1: affect us on an everyday basis, and they make us
3:05
Speaker 1: all curious about what our place in it is? And
3:09
Speaker 1: where does this all heading?
3:10
Speaker 2: Some sort of white chocolate apocalypse that's where we're heading.
3:15
Speaker 1: Wait, is that a dark vision of the future or
3:17
Speaker 1: a bright vision of the future.
3:20
Speaker 2: I think people's reactions that will tell us a lot
3:21
Speaker 2: about who they are deep down.
3:23
Speaker 1: Yeah, So if they like white chocolate, they're optimists and
3:26
Speaker 1: happy people.
3:28
Speaker 2: Some of us will run screaming from that kind of person.
3:32
Speaker 2: But I'm not the kind of person who runs screaming
3:34
Speaker 2: when I get emails from listeners. I love those emails.
3:37
Speaker 2: I love hearing your questions about the universe. I love
3:40
Speaker 2: thinking with you about the edge of your knowledge or
3:42
Speaker 2: the edge of human knowledge, which listeners often creep right
3:46
Speaker 2: up into. So please don't be shy send me your
3:49
Speaker 2: questions to questions at Danielandjorge dot com. We write back
3:53
Speaker 2: to everybody.
3:54
Speaker 1: Yeah, and sometimes we take those questions and we try
3:56
Speaker 1: to answer them here on the podcast, or at least
3:58
Speaker 1: we talk about them, which sometimes involves an answer.
4:03
Speaker 2: That's right. Some of the questions I get over email.
4:06
Speaker 2: I think lots of people might have this question, and
4:08
Speaker 2: so I'd like to share the question and the answer
4:11
Speaker 2: with the whole podcast community. Other questions I have no
4:14
Speaker 2: answer to, and so I just hope that we can
4:16
Speaker 2: fill some time with jokes and speculation in lieu of
4:18
Speaker 2: an answer.
4:19
Speaker 1: So TODA podcast we'll be tackling listener questions number sixty three,
4:29
Speaker 1: and today we have three pretty awesome questions. One of
4:32
Speaker 1: them is about hawking radiation. The only one is about
4:35
Speaker 1: making new matter in the universe. And then we have
4:38
Speaker 1: a question about the ultimate.
4:41
Speaker 2: Particle and the ultimate anti particle.
4:43
Speaker 1: Oh wait, is the ultimate antiparticle just the first particle?
4:48
Speaker 2: That's basically Brett's question.
4:49
Speaker 1: You all right, let's dig into it. Our first question
4:52
Speaker 1: comes from Andrew.
4:53
Speaker 3: Hi, Daniel, and Jorge. This is Andrea, and I have
4:56
Speaker 3: a question about Hawking radiation. I was interested in something
4:59
Speaker 3: you said another episode about it being impossible to detect,
5:03
Speaker 3: and I was wondering if you could talk a bit
5:05
Speaker 3: more about that, and especially in terms of analysis and
5:11
Speaker 3: detection and instruments and experiments. For example, have any lab
5:17
Speaker 3: experiments or simulations already been done to look for Hawking radiation?
5:24
Speaker 3: If we could develop an instrument, because I imagine this
5:27
Speaker 3: is just very theoretical at this point, but if we
5:29
Speaker 3: could develop an instrument to use on a real black
5:32
Speaker 3: hole in space to analyze the Hawking radiation, what would
5:36
Speaker 3: that require and what would that look like? Also, would
5:40
Speaker 3: only some kinds of black holes be feasible for this
5:43
Speaker 3: kind of analysis, like maybe the one at the center
5:46
Speaker 3: of our galaxy is too massive? So thank you very
5:51
Speaker 3: much for taking my question. I love the show.
5:54
Speaker 1: Awesome question. It's all about Hawking radiation. You know, can
5:59
Speaker 1: you have we detected it? Is it just an idea
6:01
Speaker 1: that we have or is it a proven concept? And
6:05
Speaker 1: if we haven't detected it, how would you measure it?
6:07
Speaker 1: And what's at the source of Stephen Hawkins is superpowers?
6:13
Speaker 2: I think that was just his sheer sex appeal.
6:15
Speaker 1: He admitted rhiz waves.
6:18
Speaker 2: That's right, rhiz particles. Actually it's quantum. Yeah, this is
6:22
Speaker 2: a great question because I love the sort of forward thinking,
6:25
Speaker 2: like how can we actually figure this out? What technology
6:27
Speaker 2: would we need? How can we make this practical? Like
6:31
Speaker 2: me Andrea really really wants to see a black hole
6:33
Speaker 2: and study it, and this is like one of the
6:35
Speaker 2: only ways we can really do that.
6:37
Speaker 1: Well, maybe you start with the basics, like what is
6:39
Speaker 1: exactly Hawking radiation and have we seen it?
6:42
Speaker 2: Hawking radiation is a super fascinating concept because it's like
6:45
Speaker 2: a first step between our current understanding of black holes,
6:48
Speaker 2: which is basically just what general relativity says that matter
6:52
Speaker 2: falls in it creates an event horizon inside is a singularity,
6:56
Speaker 2: nothing can escape. Black holes are truly black according to
6:59
Speaker 2: general relativity. But we know that general relativity can't be
7:02
Speaker 2: an ultimate description of the universe because it's ignoring quantum effects.
7:06
Speaker 2: And we know that quantum effects have to be important
7:09
Speaker 2: when you get really really dense and really really small
7:11
Speaker 2: things like a singularity. But we don't have a theory
7:15
Speaker 2: of quantum gravity something that unifies general relativity and quantum mechanics.
7:19
Speaker 2: It gives us like a description of a quantum black hole.
7:22
Speaker 2: But Stephen Hawking did something like take a first step
7:25
Speaker 2: in that direction, and he figured out that if you
7:27
Speaker 2: have a black hole in our universe, it follows the
7:30
Speaker 2: rules of general relativity, but also has to follow the
7:32
Speaker 2: rules of quantum mechanics. And he was able to bring
7:34
Speaker 2: the math together to make it play nicely. And it
7:37
Speaker 2: predicts that these quantum black holes are not truly black.
7:40
Speaker 2: They actually faintly glow with radiation, and that's the Hawking radiation.
7:45
Speaker 1: M Wait, so he was actually able to make quantum
7:49
Speaker 1: mechanics play nicely with special or general relativity. I thought
7:53
Speaker 1: that was sort of impossible.
7:54
Speaker 2: It's hopefully not impossible, because that would mean the universe
7:58
Speaker 2: can to be understood. It's so far not been achieved
8:02
Speaker 2: in a comprehensive and coherent way, but there are places
8:05
Speaker 2: where people have made a few inroads. And so we
8:07
Speaker 2: call this semi classical because he didn't make a complete
8:10
Speaker 2: theory of quantum gravity. He just pulls some really clever
8:13
Speaker 2: tricks in order to do this one calculation without actually
8:16
Speaker 2: knowing the theory of quantum gravity. So it's a really
8:18
Speaker 2: slick sort of mathematical maneuver that he did.
8:21
Speaker 1: Well, what is it exactly?
8:22
Speaker 2: So what he did is he thought about what happens
8:24
Speaker 2: to quantum fields near a black hole. Now you often
8:27
Speaker 2: hear in popular science this sort of handwavy description of
8:30
Speaker 2: Hawking radiation, and the description goes something like a particle
8:34
Speaker 2: and an anti particle and made near the event horizon.
8:37
Speaker 2: One falls in the other one is Hawking radiation. That's
8:39
Speaker 2: not what's going on as far as we know. In fact,
8:41
Speaker 2: we don't have any understanding of the particle picture of
8:45
Speaker 2: how this works, because again we don't have that theory
8:47
Speaker 2: of quantum gravity. We don't know how gravity affects these
8:50
Speaker 2: tiny particles. What Hawking did instead was think about fields
8:53
Speaker 2: near the event horizon. A lot of fields have this
8:56
Speaker 2: property that they can do two things. They can make
8:58
Speaker 2: particles and they can make anti particles. Or for example,
9:01
Speaker 2: electroagnetic fields can make fields of all sorts of different frequencies.
9:06
Speaker 2: And what he did was he said, well, how do
9:08
Speaker 2: we think about those fields near and event horizon? Because
9:11
Speaker 2: when you solve field equations, you're thinking about how waves
9:13
Speaker 2: move through those fields. And the math that he did
9:17
Speaker 2: showed us that near an event horizon, there's something weird
9:20
Speaker 2: that happens to those fields. And basically there always has
9:23
Speaker 2: to be an outgoing wave in order to make the
9:25
Speaker 2: mathematics work.
9:27
Speaker 1: Well, what do you mean like an outgoing wave? What
9:28
Speaker 1: does that mean? Outgoing in which directing like away from
9:31
Speaker 1: the black hole.
9:32
Speaker 2: Like awave from the black hole exactly. And so that's
9:34
Speaker 2: what's interpreted as outgoing Hawking radiation, the generation of particles
9:40
Speaker 2: from the energy of the black hole. That's what this
9:43
Speaker 2: radiation comes from.
9:44
Speaker 1: Now, where does this idea that there has to be
9:46
Speaker 1: a radiation come from? Is there no explanation to it?
9:50
Speaker 2: You can try to make some intuitive sense of it,
9:52
Speaker 2: but we don't have any microphysics explanation of it. Like
9:55
Speaker 2: we want one. I can hear that you want it.
9:57
Speaker 2: I'm sure listeners want it. I desperately want it, Like
10:00
Speaker 2: what's actually happening? We don't have that understanding because we
10:03
Speaker 2: don't understand particles and gravity. There's another way to gain
10:06
Speaker 2: some intuition about it, which is thermodynamically. Think about black
10:09
Speaker 2: holes as having a temperature. Right, everything in the universe
10:13
Speaker 2: that has a temperature glows, so black holes also have
10:16
Speaker 2: a temperature. Then they must also glow. And black holes
10:20
Speaker 2: because the information that falls in them have to have
10:22
Speaker 2: an entropy and therefore to have a temperature. And so
10:24
Speaker 2: that's another way to think about what hawking radiation is.
10:27
Speaker 2: It's like the black body radiation of a black hole.
10:31
Speaker 1: But wait, it sounds like you have to treat the
10:33
Speaker 1: black hole as a whole if you're talking about entropy
10:37
Speaker 1: and things like that, So then how is it quantum
10:39
Speaker 1: as well?
10:39
Speaker 2: Yeah, the quantum aspect has to do with these waves,
10:42
Speaker 2: these quantized fields that surround the black hole, and Hawking
10:46
Speaker 2: radiation comes from when you have quantum fields and an
10:49
Speaker 2: event horizon together, you get this generation of waves that
10:54
Speaker 2: come away from the event horizon. That's what hawking radiation is.
10:57
Speaker 1: So it's just I mean black body radiation that happens
11:00
Speaker 1: when like something you have a hot rock in space.
11:03
Speaker 1: It's just the molecules and atoms in it are very
11:06
Speaker 1: excited and so they generate photons that you know shoot out.
11:10
Speaker 1: Is that kind of what's happening, Like the black hole
11:12
Speaker 1: is just randomly shooting photons.
11:14
Speaker 2: Yeah, that's our microphysics understanding of normal black body radiation.
11:18
Speaker 2: You're totally right. There's like motion within a rock, for example,
11:21
Speaker 2: it has some temperature to it, and so photons will escape,
11:25
Speaker 2: and that's well described by black body radiation. In terms
11:27
Speaker 2: of a black hole, we don't know what's going on
11:29
Speaker 2: from the microphysics point of view. We don't understand the
11:32
Speaker 2: event horizon and can't think about that in terms of particles,
11:35
Speaker 2: so we have no picture to provide for like what's
11:38
Speaker 2: generating this radiation other than these mathematical solutions to the
11:42
Speaker 2: wave equation near an event horizon. You can think about
11:45
Speaker 2: it thermodynamically also to interpret the black holes having a temperature,
11:49
Speaker 2: but you don't really know what that temperature means. It
11:50
Speaker 2: doesn't reflect necessarily the kinetic energy of particles within the
11:54
Speaker 2: black hole. We don't know how to interpret that because
11:57
Speaker 2: again we don't have that theory, So we're kind of
11:59
Speaker 2: black theoretically there.
12:01
Speaker 1: Well, what about this idea that you do see in
12:04
Speaker 1: popular culture and popular science a lot that you know,
12:07
Speaker 1: at the edge of a black hole, there's two particles
12:09
Speaker 1: being created. One of them falls in, the other one
12:11
Speaker 1: spews out, and that's kind of what is hawking radiation?
12:14
Speaker 1: Does that not happen or we don't know if it happens.
12:17
Speaker 2: That could be what happens, but we don't know how
12:20
Speaker 2: particles operate near an event horizon. We don't know if
12:23
Speaker 2: gravity is a classical force which would require these particles
12:26
Speaker 2: to collapse their probabilities, or if gravity is quantum, which
12:30
Speaker 2: means that it can interact with the various possibilities of
12:33
Speaker 2: the particles. And so we don't know how to do
12:35
Speaker 2: those calculations. So we don't know what happens to particle
12:38
Speaker 2: anti particle pairs near to vent horizon. So yeah, the
12:40
Speaker 2: answer is we don't know.
12:41
Speaker 1: That could be correct, so they could maybe explain what
12:44
Speaker 1: is hawking radiation.
12:45
Speaker 2: There is definitely an explanation for hawking radiation if it
12:48
Speaker 2: is a real thing in the universe. We just don't
12:50
Speaker 2: have it. And yes, it could be that one, but
12:53
Speaker 2: there's no theory behind that. That's just like a handwavy cartoon.
12:57
Speaker 1: And what's throwing with handwavy cartoons? Daniel, you can't my
13:02
Speaker 1: career you're talking about.
13:05
Speaker 2: Yeah, they're wonderful, but they're not necessarily accurate and you
13:07
Speaker 2: can't use them to do calculations or anything. That's all
13:10
Speaker 2: they are is just a handwavy cartoon.
13:12
Speaker 1: Are there other possible handwavy cartoony explanations or is that
13:16
Speaker 1: the only one that we have?
13:17
Speaker 2: I mean, in popular science you'll see all sorts of
13:19
Speaker 2: descriptions of Hawking radiation, most of which are wrong. The
13:22
Speaker 2: ones that are most accurate either rely on this thermodynamic
13:25
Speaker 2: description or Hawking's actual calculation using boundary conditions for waves
13:31
Speaker 2: near an event horizon.
13:32
Speaker 1: But you're saying they're not wrong. We just don't know
13:34
Speaker 1: what the real answer is.
13:36
Speaker 2: Yeah, that's right. It's like the universe has a number
13:38
Speaker 2: in its head between one and a million, and you
13:40
Speaker 2: might say, well, Daniel, is it seventy four? And we're like, well,
13:42
Speaker 2: I could be seventy four, but yeah, I mean, who knows.
13:45
Speaker 1: But so far, Hawking radiation is a concept, right, Like,
13:48
Speaker 1: do have we actually ever measured this at all or
13:52
Speaker 1: seen it? Or is it just sort of an idea
13:54
Speaker 1: that physicists think is happening at black holes?
13:57
Speaker 2: It's currently still just an idea. We've never seen hawking
14:01
Speaker 2: radiation and it would be really challenging to ever see
14:04
Speaker 2: it because hawking radiation is extraordinarily faint for large black holes.
14:09
Speaker 1: Are you saying that we haven't seen it, so we
14:12
Speaker 1: don't know what it is, So it's basically a handwavy cartoon.
14:17
Speaker 2: We have lots of theories we have not proven, like
14:19
Speaker 2: string theory, which is much more than a handwavy cartoon.
14:21
Speaker 2: Because our physical principles and calculations, you can make predictions,
14:25
Speaker 2: et cetera, et cetera. So not everything that hasn't been
14:27
Speaker 2: observed is a handwavy cartoon. But yet we have never
14:31
Speaker 2: seen hawking radiation, and the challenge is that it's super
14:34
Speaker 2: duper faint. Like larger black holes are colder, which means
14:39
Speaker 2: they glow more faintly. So the smaller black hole is
14:42
Speaker 2: the hotter it is, the brighter it glows. So, for example,
14:45
Speaker 2: a black hole that has the mass of our sun,
14:47
Speaker 2: which is already a pretty small black hole, but have
14:50
Speaker 2: a temperature of sixty nanokelvins, which makes it very dark
14:53
Speaker 2: and very cold, and any glow it has would be
14:56
Speaker 2: very very faint.
14:57
Speaker 1: Wait wait, wait, what does it even mean to for
14:59
Speaker 1: a black hole to temperature. Like if a rock is
15:01
Speaker 1: a temperature, that means it captures you know, the movement
15:05
Speaker 1: of the molecules inside the rock somehow, right, Like a
15:07
Speaker 1: hot something hot means that all of its molecules are
15:10
Speaker 1: moving a lot. They have a lot of kinetic energy.
15:11
Speaker 1: What would it mean for a black hole?
15:13
Speaker 2: Yeah, we don't know. I mean, Thummer dynamics is often
15:16
Speaker 2: not about the microscopic picture. You don't have to understand
15:19
Speaker 2: what's going on inside to have these macroscopic descriptions of
15:23
Speaker 2: entropy and temperature, etc. Really justus sort of like high
15:26
Speaker 2: level summaries for what's going on inside. Sometimes you can
15:30
Speaker 2: make these connections, like for the ideal gas law between
15:33
Speaker 2: the microphysics and the macrophysics. But no, we don't know
15:36
Speaker 2: what temperature really means for a black hole. There are
15:38
Speaker 2: some arguments about information and entropy and connecting it to temperature,
15:43
Speaker 2: but that's a whole rabbit hole that Andrea didn't ask
15:46
Speaker 2: us about. In this case, you should just think about
15:48
Speaker 2: the temperature as determining the glow of the black hole.
15:50
Speaker 2: Higher temperature glows in higher frequencies.
15:53
Speaker 1: It glows via the hawking radiation, yeah, exactly, which we
15:57
Speaker 1: don't know is real or not.
15:58
Speaker 2: We don't know if it's real or not, but it
16:00
Speaker 2: makes predictions. You have this temperature, you can use the
16:02
Speaker 2: black body radiation curve. You can say, okay, a sixty
16:05
Speaker 2: nanokelvin black hole would emit this number of photons at
16:09
Speaker 2: this frequency, and you can look for that. But the
16:11
Speaker 2: thing is it's very very faint, and so it's very
16:14
Speaker 2: hard to see. For a couple of reasons. One, black
16:17
Speaker 2: holes are really far away. That's a good thing if
16:20
Speaker 2: you want to survive, but a bad thing if you
16:22
Speaker 2: want to study them. And number two is black holes
16:25
Speaker 2: are usually surrounded by other really hot stuff that's glowing
16:29
Speaker 2: very very brightly. So you're looking for a very faint
16:32
Speaker 2: glow from something otherwise very bright and very far away.
16:37
Speaker 1: How faint are we talking about, like basically the equivalent
16:39
Speaker 1: of how much a rock that is sixteen nanokelving how
16:43
Speaker 1: much it would glow in the infrared, which is probably
16:46
Speaker 1: like almost nothing at all, Almost.
16:48
Speaker 2: Nothing at all, Yeah, exactly. Now, Andrew asks like, how
16:50
Speaker 2: could you possibly ever see it? Well, you know, you'd
16:53
Speaker 2: need super duper sensitive deep infrared sensors and you need
16:58
Speaker 2: to be near enough the black hole you could which
17:00
Speaker 2: are some of these rare photons, then you might be
17:03
Speaker 2: able to pick it out because it would have a
17:05
Speaker 2: different spectrum than the rest of the stuff, like the
17:07
Speaker 2: stuff around the black hole, the accretion disk of hot gas.
17:10
Speaker 2: It's going to glow mostly like in the X ray
17:12
Speaker 2: because it's very hot, and so if you look at
17:14
Speaker 2: the very red end of the spectrum and you have
17:16
Speaker 2: very sensitive devices, then you might be able to pick
17:19
Speaker 2: this out.
17:21
Speaker 1: I wonder if it would get washed in the cosmic
17:25
Speaker 1: background the noise of light, right, like, aren't we bathed
17:28
Speaker 1: in infrared light just from the universe sort of glowing?
17:32
Speaker 2: Yeah, exactly, we are. That's a great point. The temperature
17:35
Speaker 2: of that light is around two point seven degreas calvin,
17:39
Speaker 2: so that's very hot compared to black holes, which tells
17:42
Speaker 2: you that this would be much fainter and much much
17:44
Speaker 2: much redder. Now black holes get small, then they do
17:47
Speaker 2: get brighter. The temperature goes like inverse mass, and so
17:51
Speaker 2: if a black hole was left on its own, it
17:53
Speaker 2: would very faintly glow. It would lose mass and then
17:56
Speaker 2: get brighter. And because it's getting brighter, it's losing mass faster,
18:00
Speaker 2: so you have this runaway effect where eventually a black
18:02
Speaker 2: hole evaporates, and near the very end, when it's very
18:05
Speaker 2: very small, it gets quite hot, and then the hawking
18:08
Speaker 2: radiation would be visible. So seeing a big black hole
18:11
Speaker 2: would be difficult. Seeing a disappearing black hole would be
18:15
Speaker 2: much more possible.
18:16
Speaker 1: Well, as it gets smaller, it becomes hotter. So you're
18:20
Speaker 1: saying it would be admit more photons, but would it
18:22
Speaker 1: actually be brighter because it's also smaller. I wonder if
18:25
Speaker 1: if maybe those things would balance out and it would
18:28
Speaker 1: just be as faint like a tiny black hole a
18:30
Speaker 1: million kilometers aways. It's about as fant as a giant
18:33
Speaker 1: black hole that's colder, isn't it.
18:35
Speaker 2: The event horizon does shrink, which reduces the intensity, but
18:39
Speaker 2: the temperature increasing overwhelms that, and so we expect a
18:42
Speaker 2: smaller black hole to actually be brighter. It's not just
18:46
Speaker 2: that the frequency of the radiation goes up, but the
18:48
Speaker 2: intensity of it also will even though the event horizon
18:50
Speaker 2: is getting smaller, So smaller black holes might evaporate in
18:54
Speaker 2: a way we could actually see, And people have looked
18:56
Speaker 2: for this in the night sky because if there were
18:59
Speaker 2: small black hole holes made during the Big Bang, their
19:02
Speaker 2: lifetime might be a few billion years. And if they're
19:06
Speaker 2: just sort of like scattered out in space, not near
19:09
Speaker 2: some huge source of mass, they could be isolated and
19:12
Speaker 2: they could be evaporating, and they could glow with these
19:14
Speaker 2: brilliant pinpricks of light. People have looked for them, nobody's
19:18
Speaker 2: ever seen one. But that doesn't mean that we won't.
19:20
Speaker 1: Like what size are we talking about, Like I imagine
19:22
Speaker 1: maybe there's like an optimal size for us to see them,
19:24
Speaker 1: because if they're too small, they're too small to see.
19:27
Speaker 1: But if they're too big, they're too cold to see.
19:29
Speaker 1: Is there are wonder if there's an optimal Hawking black
19:32
Speaker 1: hole size to see.
19:33
Speaker 2: The lifetime of a black hole is very very long,
19:35
Speaker 2: if it's any size at all. Like if you took
19:38
Speaker 2: a black hole that had the mass of our Sun
19:40
Speaker 2: and you put it in empty space, it would take
19:42
Speaker 2: ten to the sixty three years to evaporate. Most of
19:46
Speaker 2: that time it would be glowing so faintly its mass
19:49
Speaker 2: would hardly be dropping. A lot of the progress is
19:51
Speaker 2: made near the end because of the runaway effect. A
19:53
Speaker 2: much much smaller black hole, of course, could only take
19:55
Speaker 2: a few billion years so smaller black holes are better
19:58
Speaker 2: for observing hawking res and that's why people are thinking
20:01
Speaker 2: about primordial black holes, because stellar collapse or galactic centers,
20:06
Speaker 2: these produce huge black holes. If you want to see
20:09
Speaker 2: hawking radiation, you need little ones. That's why people are
20:11
Speaker 2: looking for black holes that come from the Big Bang,
20:14
Speaker 2: where it might have made a whole spectrum of black holes,
20:16
Speaker 2: from super massive ones to super duper tiny ones.
20:19
Speaker 1: But don't they also say that at the Large had
20:21
Speaker 1: drink collider years you're sort of making black holes.
20:24
Speaker 2: We are looking for black holes at the Large had
20:26
Speaker 2: drunk Collider. One idea might be that gravity doesn't behave
20:29
Speaker 2: the way we expect. If you get things really really
20:32
Speaker 2: close together, gravity actually gets very very strong. We've never
20:35
Speaker 2: really tested gravity over extraordinarily short distance scales, so it
20:39
Speaker 2: might be that if you smash two protons together, when
20:42
Speaker 2: they get really close together, gravity gets really strong and
20:44
Speaker 2: it forms a tiny black hole, which would then almost
20:47
Speaker 2: instantly evaporate but leave a spectrum of hawking radiation which
20:51
Speaker 2: we could see in our detectors. So we looked for
20:54
Speaker 2: hawking radiation at the Large hair Drunk Colider but never
20:57
Speaker 2: seen it. So there's lots of ways you might see
20:59
Speaker 2: hawks radiation, but yeah, and so far nothing.
21:02
Speaker 1: But do you expect there to be black holes? And
21:04
Speaker 1: in these collisions you're creating? Or I mean, is it
21:07
Speaker 1: surprising you haven't seen a hawking radiation at the large
21:10
Speaker 1: Hadron collide?
21:11
Speaker 2: Whether you expect to see them depends on a bunch
21:13
Speaker 2: of theoretical questions we don't have answers too, like are
21:16
Speaker 2: there additional spatial dimensions? What are the parameters of those dimensions?
21:21
Speaker 2: You need those spatial dimensions to explain why gravity gets
21:24
Speaker 2: stronger as things gets closer. And so if for some
21:27
Speaker 2: scenarios we would have expected to see the black holes already,
21:30
Speaker 2: in other scenarios we wouldn't have expected to see them,
21:33
Speaker 2: and so the answer is a bit muddy. Also, those
21:36
Speaker 2: calculations are even more handwaving than the Hawking radiation calculations themselves,
21:40
Speaker 2: Like some listeners might think, hold on, you just told
21:42
Speaker 2: us we don't understand gravity for particles, So how can
21:44
Speaker 2: you talk about the gravitational force between two protons when
21:47
Speaker 2: they're really close to each other? And the answer is
21:49
Speaker 2: we can't. People have done a bunch of back of
21:51
Speaker 2: the envelopes, sketchy hand wavy cartoon calculations. We don't really
21:55
Speaker 2: know whether those are right. So it's just sort of
21:58
Speaker 2: like a, oh, we should look for this in case
21:59
Speaker 2: it's there. It's not so much that if we didn't
22:01
Speaker 2: see it, we're sure it's not there. There's lots of
22:04
Speaker 2: reasons why it might not happen, all right.
22:06
Speaker 1: So then the answer for Andra is a tall a
22:08
Speaker 1: handwavy cartoon Andre. It's like asking for an explanation of
22:13
Speaker 1: something that we're not sure exists or know how it works.
22:17
Speaker 2: Kind of, but we hope one day to see this.
22:19
Speaker 2: If we do see hawking radiation, that confirms something important.
22:22
Speaker 2: It tells us that black holes are quantum objects, that
22:25
Speaker 2: they are following the quantum rules of the universe. They
22:28
Speaker 2: are not pure general relativistic black holes, that black holes
22:32
Speaker 2: are not completely black. That would be a huge breakthrough.
22:35
Speaker 1: How bright with these black holes getting snuffed out in
22:39
Speaker 1: the cosmos beat? Would they be visible to the naked
22:41
Speaker 1: eye or only if you're wearing special glasses or do
22:46
Speaker 1: you need like special telescopes.
22:48
Speaker 2: Yeah, this is the kind of thing we use telescopes
22:50
Speaker 2: to look for, because you need to see these photons
22:52
Speaker 2: a very specific frequency range which is usually not in
22:55
Speaker 2: a visible range. Usually they're in the infrared.
22:58
Speaker 1: All right, well, I guess we need to keep looking
23:00
Speaker 1: at the sky right then, to see if we ever
23:03
Speaker 1: see these flashes.
23:04
Speaker 2: That's right, more particle colliders, more telescopes, more technological eyeballs
23:08
Speaker 2: to understand the universe.
23:10
Speaker 1: Wait, did you just try to hawk more particle colliders?
23:16
Speaker 2: Hey, you're hawking your book on every episode, so I
23:18
Speaker 2: can talk particle colliders.
23:19
Speaker 1: All right, Well, thank you Andrew for that great question.
23:22
Speaker 1: Now let's get to our next question, and it's about
23:24
Speaker 1: making new matter in the universe, So let's get to that.
23:28
Speaker 1: But first let's take a quick break.
23:43
Speaker 3: Right.
23:43
Speaker 1: We're answering listener questions here today, and our next question
23:46
Speaker 1: comes from Asif.
23:48
Speaker 4: Hi, Daniel, and Jorge. This is answer from Tom Finland.
23:52
Speaker 4: I'm a big fan of the pod and I've been
23:54
Speaker 4: wondering how difficult is it to generate new matter from energy.
23:58
Speaker 4: You have previously talked about out how unstabled particles are
24:01
Speaker 4: able to summon or pull their counterparts out of thin
24:04
Speaker 4: air to reach a stable configuration again after a collision
24:07
Speaker 4: in the Large Hadron collider. Doesn't this mean that new
24:10
Speaker 4: matter is generated from the collision energy. Would it be
24:13
Speaker 4: possible to scale up this process to keep multiplying the
24:16
Speaker 4: number of stable particles to produce macroscopic amounts of new matter.
24:20
Speaker 4: Can we only go in the direction of lower mass
24:23
Speaker 4: particles this way, or would we be able to somehow
24:25
Speaker 4: generate all different elements of the periodic table. I'm imagining
24:30
Speaker 4: a space station orbiting the Sun, generating building materials and
24:33
Speaker 4: resources to become self sustained, and starting expanding just by
24:37
Speaker 4: using the available unlimited free energy. I think it's about
24:40
Speaker 4: time to get this project started, don't you agree.
24:43
Speaker 1: Thanks guys, I'm blessing a theme here, Daniel. These are
24:46
Speaker 1: all particle questions.
24:50
Speaker 2: I'm not organizing them anymore. I'm just answering them in
24:52
Speaker 2: the order they come in. This is just a particle
24:55
Speaker 2: week over here the podcast.
24:56
Speaker 1: But this is an interesting question. I guess the question is, like,
24:59
Speaker 1: what's actually happening when you collide particles? Because I know
25:02
Speaker 1: we've talked about it being sort of this magical act
25:04
Speaker 1: where you know, two things kind of become pure energy
25:07
Speaker 1: and then matter pops out. And I guess the question
25:11
Speaker 1: is is the matter that pops out like new matter
25:14
Speaker 1: or is it possible to create new matter.
25:15
Speaker 2: Yeah, it's a really fun question and a great question,
25:18
Speaker 2: and it goes to the heart of like what is
25:20
Speaker 2: matter anyway? And if you think about the universe the
25:23
Speaker 2: way particle physicists do, you know, we have all these fields,
25:27
Speaker 2: and you can take energy from one field to another field,
25:30
Speaker 2: and when a field ripples in a certain way, that's
25:33
Speaker 2: what we call a particle. Then you could just think
25:36
Speaker 2: about energy sliding around from one kind of field to another.
25:39
Speaker 2: So you collide one kind of particle with its antiparticle
25:42
Speaker 2: and that turns into a photon for example. That's energy
25:45
Speaker 2: moving from like the electron field into the photon field.
25:48
Speaker 2: Now that photon can turn into something else even heavier
25:52
Speaker 2: than the original electrons, like a muon and an anti muon.
25:55
Speaker 2: That's the energy sliding from the photon field to the
25:59
Speaker 2: muon field. And those different states can have different amounts
26:02
Speaker 2: of mass, right, So the electron has low mass, the
26:06
Speaker 2: photon has no mass, the muon has high mass. Mass
26:10
Speaker 2: is just stored internal energy of some of these states.
26:13
Speaker 2: So mass is not like a special thing or hard
26:15
Speaker 2: to make in the universe. It's just a kind of
26:18
Speaker 2: energy that these fields can have.
26:20
Speaker 1: How would you define what matter is or does it
26:22
Speaker 1: not even make sense to use the word, like maybe
26:25
Speaker 1: we should just get rid of the word.
26:26
Speaker 2: No, it's a good question. I think there's a couple
26:28
Speaker 2: of concepts of what matter is, which is separate from
26:31
Speaker 2: the idea of mass. Right, And when we talk about matter,
26:33
Speaker 2: one sense in which it makes sense is like the
26:35
Speaker 2: stuff we're made out of, stable stuff which hangs out
26:38
Speaker 2: in the universe building blocks for our existence. Right, we
26:42
Speaker 2: are made of matter. We eat things made of matter,
26:46
Speaker 2: and you know, quarks and electrons come together to make
26:49
Speaker 2: all this amazing complexity that's matter. Sometimes also extend that
26:53
Speaker 2: though to other related particles that are not stable, Like
26:57
Speaker 2: we think of a muon as a matter particle, but
27:00
Speaker 2: muons last four microseconds before they decay into other stuff.
27:03
Speaker 2: You can't build anything out of muons. You can't have
27:06
Speaker 2: life made out of muons or a meal made out
27:09
Speaker 2: of muons. So I think the concept of matter comes
27:12
Speaker 2: from the stuff of our experience, and then we extend
27:15
Speaker 2: it to also similar particles. So since everything we're made
27:19
Speaker 2: out of is fermions spin one half particles, we tend
27:21
Speaker 2: to call all spin one half particles matter and other
27:25
Speaker 2: kinds of particles like photons. We call them force particles.
27:29
Speaker 2: But that distinction is a little bit arbitrary.
27:31
Speaker 1: Like basically, it's all particles in quantum field. But is
27:34
Speaker 1: there a distinction between the ones we call matter and
27:37
Speaker 1: the ones that we don't call matter? Is mass is
27:39
Speaker 1: the thing that makes something be matter.
27:41
Speaker 2: The distinction is the spin of the particles. Like all
27:44
Speaker 2: the particles we call matter, those are fermions. There's spin
27:47
Speaker 2: one half particles, and all the particles we call force
27:49
Speaker 2: particles those are spin one or spin zero particles.
27:53
Speaker 1: Like are there particles that we don't call matter but
27:56
Speaker 1: that still have mass?
27:57
Speaker 2: Yes? Absolutely there are, like the w and the z bosons.
28:01
Speaker 2: These are spin one particles. They're not fermions. We don't
28:04
Speaker 2: call them matter, but they do have mass, in fact
28:06
Speaker 2: that they're quite massive. They have the mass of like
28:09
Speaker 2: eighty or ninety times the mass of a proton. Extraordinarily
28:13
Speaker 2: massive particles, but we don't call them matter. They are
28:16
Speaker 2: the particles that communicate the weak force. But yeah, we
28:18
Speaker 2: don't call those matter particles, but they do have mass.
28:21
Speaker 2: So you can have mass and not be matter.
28:23
Speaker 1: And can you be madder without mass? Are there things
28:26
Speaker 1: that we call matter that don't have mass.
28:28
Speaker 2: Well, that's a great question. Until recently, we didn't know
28:31
Speaker 2: if neutrinos had mass. Neutrinos are in the matter category
28:34
Speaker 2: because they're fermions. Now we know they do have mass,
28:37
Speaker 2: but have an extraordinarily small, tiny, tiny, tiny amount of mass.
28:41
Speaker 2: But no, there are no particles we call matter particles
28:44
Speaker 2: which are massless.
28:46
Speaker 1: And why do we pick the spin of these particles
28:49
Speaker 1: to be the thing that distinguishes it as matter? Is
28:52
Speaker 1: that significant to like our existence?
28:54
Speaker 2: I don't think it's fundamentally significant. I think we just
28:57
Speaker 2: noticed that the stuff we're made out of is comprised
28:59
Speaker 2: of spin one half particles, and that forces tend to
29:02
Speaker 2: use spin one particles to communicate. But again, matter and forces,
29:06
Speaker 2: you know, these are sort of colloquial terms. I think
29:08
Speaker 2: the way you put it is pretty good. Like everything
29:11
Speaker 2: is just particles in a quantum field, and there's lots
29:13
Speaker 2: of different kinds of quantum fields that can do all
29:15
Speaker 2: sorts of weird things. Some of them are spin one,
29:18
Speaker 2: some of them are spin half, some of them are massless,
29:20
Speaker 2: some of them are not. There's all sorts of weird
29:22
Speaker 2: different kinds of fields out there.
29:24
Speaker 1: So then I wonder if the ass for us if
29:26
Speaker 1: is that there's just thing is matter, you know, like
29:28
Speaker 1: there's only energy that slashes around between these quantum fields,
29:32
Speaker 1: and sometimes this energy ends up in a quantum field
29:34
Speaker 1: that we just happen to call matter.
29:36
Speaker 2: Yeah, exactly, And so he's totally right that new matter
29:39
Speaker 2: can be generated from collisions. Like you pour a bunch
29:42
Speaker 2: of energy into a collision, you can make something heavy.
29:45
Speaker 2: You can turn that energy into mass, right, and that
29:49
Speaker 2: can make new matter. So yeah, and principle, you could
29:52
Speaker 2: like take two protons and smash them together and make
29:54
Speaker 2: like a gold nucleus if you had enough energy. It's
29:58
Speaker 2: pretty unlikely. And most of the time when you make
30:00
Speaker 2: something that's massive from something that's low mass, it's unstable.
30:05
Speaker 2: Like if you make a w boson or a z
30:07
Speaker 2: boson these massive particles, then it don't last very long.
30:10
Speaker 2: Because the universe doesn't typically like to have a lot
30:13
Speaker 2: of mass or a lot of energy in one place.
30:15
Speaker 2: It tends to prefer configurations with lots of possibilities, which
30:19
Speaker 2: tend to prefer configurations with lots of options, lots of
30:22
Speaker 2: quantum possibilities, and those are the ones with low mass particles.
30:26
Speaker 2: That's why things decay. That's why muans DeKay down to
30:28
Speaker 2: electrons or w particles don't last very long.
30:31
Speaker 1: Yeah, I don't like to have all of my mass
30:34
Speaker 1: in one spot.
30:34
Speaker 2: Either, exactly, diversified, diversified, diversify.
30:37
Speaker 1: Right, No, it just cuts a slimmer figure.
30:41
Speaker 2: And that's why most of the stuff we're made out
30:42
Speaker 2: of it are the lightest particles out there, because they
30:45
Speaker 2: can't decay down any further. Electrons and upquarks and down
30:48
Speaker 2: quarks are stable because there's nothing below them on the ladder.
30:52
Speaker 2: And so yeah, it's possible to take the light particles,
30:54
Speaker 2: give them energy, smash them together, make heavy particles, but
30:58
Speaker 2: typically they will not last for very long and less lucky,
31:00
Speaker 2: and you happen to form something which is stable, like
31:02
Speaker 2: an iron nucleus.
31:04
Speaker 1: Well, I wonder if it's if it's more of a
31:05
Speaker 1: philosophical question, you know, does the term new matter even
31:09
Speaker 1: make sense? What does the word new here mean? Like
31:12
Speaker 1: it didn't exist before, but you know, the energy that
31:15
Speaker 1: making that matter, it sort of existed before it just
31:18
Speaker 1: it came from a different field.
31:19
Speaker 2: Yeah, that's sort of like the particle of thesus question,
31:22
Speaker 2: you know, like is this particle new or is this
31:24
Speaker 2: particle not new?
31:25
Speaker 1: Or what does it mean to have an old particle?
31:27
Speaker 1: Like is there such a thing? Right?
31:29
Speaker 2: Particles never retire, man, they work forever, so their age
31:32
Speaker 2: doesn't matter. I think he's asking about new matter in
31:36
Speaker 2: the concept of like new elements of the periodic table,
31:39
Speaker 2: Like could we create elements of the periodic table we've
31:42
Speaker 2: never seen before by smashing particles together?
31:46
Speaker 1: Oh? Like, uh, you think as if it's asking about
31:50
Speaker 1: creating an element we had never seen before.
31:52
Speaker 2: Yeah, he says, generate all different elements of the periodic table.
31:56
Speaker 2: And to me, the question is, like, well, what are
31:58
Speaker 2: all the different elements? Even know? There might be some
32:01
Speaker 2: really heavy new ones that are very stable, that are
32:04
Speaker 2: very massive we've never made before. And so yeah, and
32:07
Speaker 2: so if one way to do that is to smash
32:09
Speaker 2: stuff together and see if we can make those heavy elements,
32:11
Speaker 2: we haven't been able to do that yet.
32:13
Speaker 1: Well, I guess maybe the question then is what's the
32:16
Speaker 1: biggest or heaviest element we have made out of scratch
32:19
Speaker 1: in in a particle collision? And I think it means
32:22
Speaker 1: like spontaneously making something right, not just like you know,
32:26
Speaker 1: like building up a matter like by adding one proton
32:29
Speaker 1: at a time.
32:30
Speaker 2: I think the heaviest thing we've ever made is element
32:32
Speaker 2: one eighteen, But that's not really what he's asking about
32:36
Speaker 2: to do that. You take lighter elements and you like
32:38
Speaker 2: gently toss protons into them, hoping not to smash them apart.
32:43
Speaker 2: So that's one technique. But if you just like start
32:45
Speaker 2: from two protons and smash them together and hope to
32:48
Speaker 2: make something like element one forty seven, that's not something
32:51
Speaker 2: we've ever done. When we smash protons together, we don't
32:53
Speaker 2: ever get helium, for example. It's possible, yeah, absolutely, but
32:56
Speaker 2: it's very delicate because you put too much energy and
32:59
Speaker 2: you just destroy the protons and you get the quarks interacting,
33:02
Speaker 2: you get fragments of the protons flying out.
33:04
Speaker 1: No, but I wonder if he means, like, you know,
33:06
Speaker 1: you take two protons, you accelerate them, you smash him,
33:08
Speaker 1: you create pure energy, like the old protons are gone,
33:12
Speaker 1: even the old quarks are gone, and then somehow all
33:15
Speaker 1: that energy somehow reforms into a complex atom.
33:19
Speaker 2: Yeah that's possible, right, and be careful again with pure energy.
33:23
Speaker 2: That's something we say sometimes, but really what's happening is
33:25
Speaker 2: that energy is going into another field. Typically it's photons
33:29
Speaker 2: or z bosons or something. But yeah, then that field
33:32
Speaker 2: can dump the energy back into quark fields, which could
33:35
Speaker 2: form protons and make a crazy heavy element. That it's
33:38
Speaker 2: totally possible. It's not something we've ever done. It's very unlikely.
33:42
Speaker 2: It requires a lot of things to go right, all
33:44
Speaker 2: at the same time. But there's nothing saying it's not possible.
33:48
Speaker 1: Well, I wonder if you've done it, you just haven't
33:49
Speaker 1: noticed or measured it or look for it.
33:52
Speaker 2: Yeah, that's absolutely possible too, because in these collisions we
33:54
Speaker 2: get huge sprays of particles, more than we can ever
33:57
Speaker 2: track or count, and we're not like sift through them
34:00
Speaker 2: usually to look for new, weird heavy nuclei.
34:03
Speaker 1: That the collider is not suddenly covered in gold you
34:06
Speaker 1: haven't noticed that, or white chocolate? Perhaps, would that be
34:09
Speaker 1: a tragedy if you like went to work one day
34:11
Speaker 1: and everything's covered in white chocolate, You're like, no.
34:17
Speaker 2: It's an exciting day every day at the particle collider.
34:20
Speaker 2: Are we going to make a black hole? Are we
34:21
Speaker 2: going to cover the Earth in white chocolate? Who knows?
34:23
Speaker 1: Let's turn it, who knows, Let's find out exactly.
34:29
Speaker 2: Let's go as the kids say.
34:31
Speaker 1: So then what's the answer for ounce of here? Is
34:34
Speaker 1: that it is possible to make a matter is just
34:36
Speaker 1: kind of unlikely.
34:38
Speaker 2: Yeah, the answer is that it's totally possible. And I
34:41
Speaker 2: love your vision of a space station orbiting the Sun
34:44
Speaker 2: building all sorts of crazy building blocks, but I'm not
34:47
Speaker 2: ready to invest.
34:48
Speaker 1: I see you need to see. The proof is in
34:50
Speaker 1: the white chocolate pudding.
34:52
Speaker 2: Yeah. If this was physics Shark Tank, I would not
34:54
Speaker 2: be in.
34:54
Speaker 1: Ooh, physics shark that.
34:56
Speaker 2: I like that.
34:57
Speaker 1: Let's make that show.
34:58
Speaker 2: All right, listen, bite, let's and designed the pictures a
35:01
Speaker 2: start the projects.
35:02
Speaker 1: Oh, I think they have that already. I think it's
35:03
Speaker 1: called the National Science Fundation. All right, well, great question. Answer.
35:09
Speaker 1: Now let's get to our last question of the day,
35:11
Speaker 1: and this one is about the ultimate particle and possibly
35:16
Speaker 1: it's anti particle. Let's dig into that, but first let's
35:20
Speaker 1: take a quick break. All right, we're answering listener questions
35:35
Speaker 1: and our last question comes from Brett.
35:38
Speaker 5: Hey, my name is Brett. I'm full Ty from the
35:39
Speaker 5: United Kingdom. I'm currently studying an integrated masters and bachelor's
35:44
Speaker 5: degree in my spare time, and I have a question
35:48
Speaker 5: for the podcast. I've been thinking about ultimate particles, God
35:52
Speaker 5: particles and fundamental particles, and I was wondering if there
35:57
Speaker 5: is a true ultimate fundamental particle that everything else comes from,
36:03
Speaker 5: would also have an anti version of itself? And also,
36:08
Speaker 5: if we can't see them now, is it possible that
36:10
Speaker 5: they're all used up in the Big Bang? And if so,
36:13
Speaker 5: would we be able to see any evidence in the CMB.
36:16
Speaker 5: And finally, third part of the question, would it be
36:20
Speaker 5: the case that different configurations of the particle make up
36:23
Speaker 5: the ones that we see in the standard model? I
36:26
Speaker 5: realized this is a bit more than one question, but
36:28
Speaker 5: thank you for your time and thank you for your responses.
36:30
Speaker 2: Hey Bretat, congrats on studying for your master's degree in
36:34
Speaker 2: physics in your spare time. That's awesome.
36:36
Speaker 1: Yeah, that's a pretty cool a master's and bachelor's degree
36:40
Speaker 1: at the same time. Well, the question is kind of cool,
36:43
Speaker 1: I guess, you know, because in popular science you hear
36:47
Speaker 1: talk of the god particle, the ultimate particle, or maybe
36:50
Speaker 1: finding out that the whole universe is just made out
36:52
Speaker 1: of one particle. And I think Brett's question is if
36:56
Speaker 1: we ever find such a particle, would it have an
36:59
Speaker 1: antipe article version of it?
37:01
Speaker 2: Yeah, super awesome question, Brett. The short answer to your
37:04
Speaker 2: question is, we have no idea because we don't know
37:08
Speaker 2: the inside these particles, but we can talk about what
37:12
Speaker 2: the current theories do predict. You know, we suspect strongly
37:16
Speaker 2: that what we're looking at now, the electrons and the quarks,
37:20
Speaker 2: are not the fundamental description of the universe. We think
37:23
Speaker 2: that probably there's some deeper explanation that accounts for all
37:27
Speaker 2: the weird patterns and like baroque details of all of
37:31
Speaker 2: these particles.
37:32
Speaker 1: Sort of like you know, when we discovered the elements,
37:34
Speaker 1: we found out there was some sort of order to
37:36
Speaker 1: them that explain why gold behaved differently than carbon, for example.
37:41
Speaker 2: Yeah, exactly, there are these patterns, these features to the
37:44
Speaker 2: particles that we see. We don't understand them. There are
37:47
Speaker 2: strong hints that they might be made out of something smaller,
37:49
Speaker 2: something simpler that explains all of these weird details. Also,
37:53
Speaker 2: we know that our theory breaks down at a certain
37:55
Speaker 2: point we have really high temperatures or like we had
37:58
Speaker 2: in the very early universe, that our current theory just
38:01
Speaker 2: doesn't work anymore. You need to fold in gravity. We
38:03
Speaker 2: don't know how to do that, so at some point
38:06
Speaker 2: our theory breaks down and that very high temperature also
38:09
Speaker 2: corresponds to very short distances. So the point of the
38:12
Speaker 2: story is we think our current theory is not complete.
38:14
Speaker 2: We hope to figure out one day what's there. And
38:17
Speaker 2: your question is basically, when we do, will that be
38:20
Speaker 2: some sort of particle antiparticle or is it possible for
38:23
Speaker 2: everything that made out of something that doesn't have an
38:25
Speaker 2: anti particle?
38:26
Speaker 1: Well, I guess maybe take a step back and let's
38:28
Speaker 1: think about whether it's possible, Like, is it possible that
38:31
Speaker 1: everything that we know about electrons, quarks they're all actually
38:36
Speaker 1: made out of one particle.
38:38
Speaker 2: Yeah, absolutely, that's possible.
38:39
Speaker 1: What wouldn't mean for the fields right right? Like don't
38:41
Speaker 1: we talk about the electron having its own quantum fields
38:44
Speaker 1: and quarks having their own quantum quark fields. That mean
38:47
Speaker 1: those fields don't really exist, they're just sort of like
38:50
Speaker 1: made up of other fields.
38:52
Speaker 2: It would mean that those fields are effective instead of fundamental.
38:55
Speaker 1: Wait, what was that word you said? If they're effective?
38:58
Speaker 2: Yeah, an effective field is one that's not fundamental. For example,
39:01
Speaker 2: if you want to think about like pressure waves in
39:04
Speaker 2: a material, you can write that down in terms of
39:06
Speaker 2: a field theory. Wave equations for how oceans work. But
39:11
Speaker 2: we know that oceans are not a fundamental field in
39:13
Speaker 2: the universe. Right, we can still think about waves in
39:16
Speaker 2: the ocean as if the oceans are a field. But
39:19
Speaker 2: that's just like useful mathematics that describes a lot of
39:22
Speaker 2: complex stuff, sweeping it under the rug without really understanding
39:26
Speaker 2: the details. So we don't know whether the fields we
39:29
Speaker 2: have now are fundamental fields or they're just effective fields.
39:32
Speaker 2: It could be that there is no electron field, that
39:35
Speaker 2: there's something deeper the squiggly on field or several squiggly
39:38
Speaker 2: on fields, and when you zoom out a little bit
39:41
Speaker 2: and so you can't see the squigglions anymore, they act
39:44
Speaker 2: like an electron field. So you can use the electron
39:47
Speaker 2: field as an effective theory. It works, it's helpful and
39:51
Speaker 2: lets you do calculations, but it might not be a
39:53
Speaker 2: true description of the deepest nature of the universe.
39:56
Speaker 1: Whoa so like all this time we thought the electron
39:59
Speaker 1: field was a fundamental and like basic feature of the universe.
40:03
Speaker 1: But no, it could just be an illusion kind of.
40:05
Speaker 2: It might be an emergent phenomena. Right, this is something
40:08
Speaker 2: we see all over the universe that you can describe things,
40:12
Speaker 2: lots of different scales. You can talk about galaxies without
40:15
Speaker 2: understanding the particles inside every planet and inside every rock. Right,
40:19
Speaker 2: you can zoom out and find simple mathematical laws. Kepler
40:23
Speaker 2: discovered those without even understanding gravity. Right, you can find
40:26
Speaker 2: simple mathematics that lots of different length scales, distance scales,
40:30
Speaker 2: energy scales in the universe. That's sort of a mystery,
40:33
Speaker 2: like why that's even possible, But yeah, you can zoom
40:36
Speaker 2: in or out in the universe and find mathematical laws.
40:39
Speaker 2: We don't know if we found the deepest layer yet,
40:42
Speaker 2: or if there even is a deepest layer, or what
40:44
Speaker 2: that looks like.
40:45
Speaker 1: Well, what would make more sense? I guess would it
40:48
Speaker 1: make more sense for there to be like all these
40:50
Speaker 1: multiple fields electron field, quark fields, muan fields, or would
40:54
Speaker 1: it make sense to just have one field to rule
40:57
Speaker 1: them all.
40:59
Speaker 2: It's a great philosophical question. We don't have a scientific
41:02
Speaker 2: answer for it, right.
41:03
Speaker 1: What do we have a song? Though?
41:07
Speaker 2: We don't have a song or a scientific answer for it.
41:09
Speaker 2: Maybe there is a song for all the particles. I
41:11
Speaker 2: don't know, but you know, if this is the fundamental theory,
41:14
Speaker 2: there is nothing below it that means that there's a
41:16
Speaker 2: lot of unanswered questions, you know, like why are there
41:19
Speaker 2: three copies of every particle electrons, muons, and towels, all
41:23
Speaker 2: sorts of questions that are out there that would be unanswered,
41:25
Speaker 2: and you might just be like, h, I don't know,
41:27
Speaker 2: that's just kind of the way it is. You'd be
41:29
Speaker 2: much more satisfying if we found a simpler explanation, because
41:32
Speaker 2: simplicity is always more satisfying because there are a few
41:35
Speaker 2: work follow up questions, but we don't know. The universe
41:37
Speaker 2: is not required to be satisfying to our minds.
41:41
Speaker 1: I wonder if you could maybe like start with one
41:43
Speaker 1: field and then try to invent or figure out how
41:47
Speaker 1: that one field could give rise to all the other fields.
41:50
Speaker 1: Is that something that people have done and discount it
41:52
Speaker 1: or is that basically what string theory is or what?
41:56
Speaker 2: Yeah, that's basically string theory. String theory says the whole
41:59
Speaker 2: universe it's man out of one kind of thing, a string,
42:02
Speaker 2: and that string can do lots of different things. They
42:05
Speaker 2: can vibrate in different ways, so it's sort of like
42:07
Speaker 2: a meta field theory. Instead of having ten different quantum
42:10
Speaker 2: fields or eighteen quantum fields, you have a string which
42:14
Speaker 2: can oscillate in different ways, and different modes of those
42:16
Speaker 2: strings correspond to the different fields that we see. So
42:21
Speaker 2: string theory can describe everything we see out there. It
42:24
Speaker 2: can even unify gravity and quantum mechanics and describe everything.
42:28
Speaker 1: But I wonder if you need to get that complicated,
42:30
Speaker 1: because I know string theory is super complex, right, it
42:32
Speaker 1: has like a bazillion dimensions to it. Couldn't you just
42:35
Speaker 1: start with like the danelon or something and then try
42:39
Speaker 1: to create one particle that's not a string, like a brierrating,
42:42
Speaker 1: just a particle, and then try to come over with
42:45
Speaker 1: the rules that would make electrons and quarks.
42:47
Speaker 2: Yeah, you definitely want the simplest explanation, right. The reason
42:50
Speaker 2: that people do string theory is that it is kind
42:52
Speaker 2: of the simplest way people have made all these pieces
42:55
Speaker 2: work together because there's a lot to describe. You know,
42:58
Speaker 2: we have all these different particles or the daniel On field,
43:01
Speaker 2: whichever has to be able to do lots of different
43:03
Speaker 2: kinds of things. That has to be able to wiggle,
43:05
Speaker 2: like an electron and a muon and a towel, and
43:08
Speaker 2: the neutrinos and the quarks and all the force particles,
43:11
Speaker 2: and it has to be able to explain quantum gravity,
43:13
Speaker 2: so you need gravitons in there as well. And string
43:17
Speaker 2: theory is sort of the simplest way people have ever
43:19
Speaker 2: made that work. A simpler theory can't explain everything that
43:23
Speaker 2: we see so far, and it's pretty simple. You just
43:25
Speaker 2: got one string.
43:26
Speaker 1: Well, I guess. Then the question is, can a string
43:29
Speaker 1: in a string theory have an anti version of itself?
43:32
Speaker 2: Yeah, that's a really cool question. And you know, somebody
43:35
Speaker 2: might one day come up with a theory of some
43:38
Speaker 2: fundamental thing that explains everything and has an anti fundamental thing.
43:42
Speaker 2: But this current idea of string theory doesn't have anti strings.
43:47
Speaker 2: And the whole idea of anti particles I think is
43:49
Speaker 2: sometimes a little bit misleading. It tells people that, like,
43:52
Speaker 2: there's an opposite kind of matter, instead of thinking of
43:55
Speaker 2: antimatter as an opposite kind of matter, thinking of it
43:57
Speaker 2: as like a complementary kind of matter, or think about
44:00
Speaker 2: it as like fields can do two different kinds of things.
44:03
Speaker 2: Your favorite band can play rock, they can also play
44:05
Speaker 2: alternative the electron. Fields can wiggle in an electron like way,
44:08
Speaker 2: you can also wiggle in an anti electron like way.
44:11
Speaker 2: It's just another thing. The same field can do. They're
44:15
Speaker 2: just strings. They can wiggle to make the electron field,
44:17
Speaker 2: which then can make electrons or anti electrons. So the
44:21
Speaker 2: short answer is there are no anti strings in string theory.
44:24
Speaker 2: You don't need them because the strings can make the field,
44:26
Speaker 2: and the field can do either the particle or the
44:29
Speaker 2: anti particle.
44:30
Speaker 1: Well, I know, and we've talked about it before. How
44:33
Speaker 1: like an antiparticle, something is just the same thing except
44:36
Speaker 1: what the charge. Charge is flipped And so I guess
44:40
Speaker 1: maybe I wonder if the question is do strings have
44:42
Speaker 1: a charge? Is such a thing as charge in string
44:45
Speaker 1: theory or is charge something that comes from the different
44:48
Speaker 1: vibrations of the string.
44:49
Speaker 2: Yeah, charge is something that comes from the different vibration
44:52
Speaker 2: of the string, because the same string can make a
44:54
Speaker 2: charged field like the electron field, and a non charge
44:57
Speaker 2: field like the electromagnetic field. And so that tells us
45:01
Speaker 2: something about like what charge is in the universe. Currently
45:03
Speaker 2: we imagine charge is conserved in the universe. But if
45:07
Speaker 2: charge things are made up of the same stuff, is
45:10
Speaker 2: not charge things, And you could might imagine you might
45:12
Speaker 2: be able to convert one to the other. You might
45:14
Speaker 2: be able to destroy or create charge by getting the
45:18
Speaker 2: string to wiggle differently.
45:19
Speaker 1: It sounds like maybe you're saying, you know, if we
45:21
Speaker 1: ever discover the ultimate theory of everything, it wouldn't have charges,
45:26
Speaker 1: in which case it wouldn't have an anti version of itself.
45:29
Speaker 2: Yeah, I think I'd pull back on that a tiny bit.
45:31
Speaker 2: I'd say it doesn't have to have charges. It might.
45:33
Speaker 2: There's no guarantee that string theory is the right description
45:36
Speaker 2: of the universe. There's lots and lots of problems with
45:39
Speaker 2: string theory and lining it up with reality and figuring
45:41
Speaker 2: out which string theory to use, et cetera. Somebody might
45:43
Speaker 2: come along with a much better, you know, rubber band
45:46
Speaker 2: theory of the universe, or the whohe On theory of
45:49
Speaker 2: the universe that might have Antijoheans in it. Who knows,
45:53
Speaker 2: So I'm not ruling it out. I'm just saying, we
45:55
Speaker 2: don't know, but our best current theory doesn't require anti strings, right,
45:59
Speaker 2: you can out.
46:00
Speaker 1: But I wonder like, if you do get to that theory,
46:02
Speaker 1: like the whorehe On theory of everything, and there's a
46:06
Speaker 1: plus Horray and a minus horhe, if them wouldn't just
46:09
Speaker 1: ask like, why is there a plus oriy and a
46:10
Speaker 1: minus hoorge. There must be something even deeper explain the
46:14
Speaker 1: plus and minus warges, right, in which case you couldn't
46:18
Speaker 1: call this the ultimate theory.
46:19
Speaker 2: Maybe, and you'll have a hard time ever proving that
46:22
Speaker 2: you have the ultimate theory because you can almost never
46:24
Speaker 2: distinguish between the two scenarios of we have the ultimate
46:27
Speaker 2: theory or we don't have the ultimate theory, but we
46:30
Speaker 2: don't have the power to see inside this one. You know,
46:32
Speaker 2: it's a question of resolution always, like can you zoom
46:35
Speaker 2: in far enough to tell what this is made out of?
46:37
Speaker 2: Can you tell whether it's made out of itself or
46:39
Speaker 2: something smaller? But you could also end up in a
46:41
Speaker 2: situation where you have a theory with a plus Jorge
46:44
Speaker 2: and a minus Orge, and you understand why that there's
46:47
Speaker 2: a symmetry to it, it's a balance to it, or there's
46:49
Speaker 2: some sort of structure to it that demands requires a
46:52
Speaker 2: plus and a minus. So it might be that the
46:55
Speaker 2: question is answered on its own without going to a
46:57
Speaker 2: deeper theory.
46:58
Speaker 1: But who knows, well, I guess for it to have
47:01
Speaker 1: an anti version of itself, you would have to kind
47:04
Speaker 1: of pick one as the dominant one, right, kind of
47:08
Speaker 1: like because we only call antimatter antimatter because it's not
47:11
Speaker 1: the same as the kind that we're made out of.
47:13
Speaker 2: Yeah, and that's not something we understand in our universe.
47:16
Speaker 2: Like why we tend to be made out of one
47:18
Speaker 2: half of this symmetry and not the other half. That's
47:20
Speaker 2: a huge open question.
47:22
Speaker 1: Well, any theory of everything that has me at the
47:24
Speaker 1: center of it, For me, I think that's the ultimate theory.
47:27
Speaker 2: That's everything.
47:28
Speaker 1: Let's just stop right there. Yes, if I'm at the
47:30
Speaker 1: center of the universe, let's not look any further.
47:34
Speaker 2: Forget Aristotle, forget Copernicus. We have the whoreey theory, the
47:38
Speaker 2: whoregey centric theory of the universe.
47:40
Speaker 1: That's right, Yes, that's all you need.
47:43
Speaker 2: Nobody tell the Catholic Church.
47:44
Speaker 1: And at the core of it is just to handwavy cartoon.
47:50
Speaker 2: It's a good way to live, man, Yeah.
47:53
Speaker 1: I know, all right. Well, I think that's the answer
47:56
Speaker 1: for bread, which is that it is possible if we
47:59
Speaker 1: find the god part or the ultimate particle of matter
48:03
Speaker 1: in the universe and forces that it might have its
48:06
Speaker 1: own anti particle, it's anti god particle. Would it be
48:10
Speaker 1: the anti god particle or the godless particle?
48:13
Speaker 2: The devil particle. Yeah, who knows, But the dog particle
48:17
Speaker 2: I like that better.
48:18
Speaker 1: Yeah, but then are we made out of dog particles
48:20
Speaker 1: or God particles?
48:22
Speaker 2: I want to be a cat particle. I don't know,
48:24
Speaker 2: but I love that Brett is thinking about this. I
48:26
Speaker 2: want everyone out there to think about the deep nature
48:28
Speaker 2: of the universe. You don't have to be a professional
48:30
Speaker 2: physicist or even on your way to becoming one. This
48:33
Speaker 2: is a mystery that belongs to everyone.
48:35
Speaker 1: Yeah, we hope everyone has questions and also anti questions.
48:39
Speaker 2: Are our answers anti questions?
48:40
Speaker 1: To Zach Can, they're definitely anti answers most of the time.
48:45
Speaker 2: Well, I hope when we collide our anti answers with
48:48
Speaker 2: your anti questions, we're not annihilating your curiosity. That's right.
48:51
Speaker 1: We're just creating positive why.
48:53
Speaker 2: Is all over the place and hoping it matters.
48:56
Speaker 1: All right. Well, I think that answers all of our questions.
48:59
Speaker 1: Thanks to everyone who sent in their questions. We always
49:03
Speaker 1: enjoy talking about these adventures into people's curiosity. We hope
49:08
Speaker 1: you enjoyed that. Thanks for joining us. See you next time.
49:16
Speaker 2: For more science and curiosity. Come find us on social media,
49:19
Speaker 2: where we answer questions and post videos we're on Twitter,
49:23
Speaker 2: this Org, instant and now TikTok. Thanks for listening and
49:26
Speaker 2: remember that Daniel and Jorge Explain the Universe is a
49:29
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49:35
Speaker 2: Apple Podcasts, or wherever you listen to your favorite shows.