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The mysterious phenomenon of turning sound into light · Daniel and Kelly’s Extraordinary Universe

0:08
Speaker 1: Hey, Jorge, are you a sinnisthite? Oh? Is that like
0:12
Speaker 1: a religiously No, it's a person who can see sounds
0:18
Speaker 1: like Do I see a symphony of colors when I
0:20
Speaker 1: hear classical music? Yeah? Exactly. I know that a lot
0:23
Speaker 1: of visual artists have some of that. Well, I do
0:26
Speaker 1: see red when my kids are too loud. Does that count?
0:30
Speaker 1: I don't know. Maybe it just means you're singing the
0:32
Speaker 1: parental blues. Well, orange, use mark. Those are all the
0:36
Speaker 1: color jokes I could think of. Yeah, let's not get
0:38
Speaker 1: into off color jokes. Hi, I'm Orhammed, cartoonists and the
0:56
Speaker 1: creator of PhD comics. Hi, I'm Daniel. I'm a particle
0:59
Speaker 1: physicist and a professor at you see Irvine. What color
1:03
Speaker 1: would you describe your job as? Blue and gold? Of course,
1:06
Speaker 1: the colors of use. Wow, you got the school spirit
1:11
Speaker 1: to the core. I do believe in the mission of
1:13
Speaker 1: the University of California. Actually, we are the biggest public
1:16
Speaker 1: school system I think in the world, educate lots of
1:19
Speaker 1: people who otherwise couldn't afford to go to college. So yeah,
1:22
Speaker 1: that's why I'm at a public university. Yeah, you sees
1:25
Speaker 1: are awesome. And now do you identify as an art
1:27
Speaker 1: vark or a bear because I know you went to Berkeley,
1:30
Speaker 1: but now you work at easy Irvine. Well, i'd like
1:32
Speaker 1: to say bear to stand up against your Stanford tree.
1:35
Speaker 1: Is it a tree? It is? Unfortunately? Are the Stanford
1:39
Speaker 1: masket is a tree? Is it a shivering cedar or something?
1:43
Speaker 1: It actually changes every year? Yeah, it's a different tree
1:47
Speaker 1: each year. No, but it's been a long time since
1:49
Speaker 1: I was at Berkeley, so I definitely associate with you.
1:51
Speaker 1: See Irvine's art vark. I like a mascot that's not
1:54
Speaker 1: ferocious but a little bit cookie, right, and then eats insects.
1:58
Speaker 1: That's pretty cool. I've eaten ants myself. They're actually quite tasty.
2:01
Speaker 1: You have turned into an art park, maybe z Welcome
2:05
Speaker 1: to our podcast Daniel and Jorge Explain the Universe, a
2:07
Speaker 1: production of My Heart Radio in which we feed you
2:10
Speaker 1: tasty little tidbits of knowledge about the universe. No ants here,
2:14
Speaker 1: but lots of amazing facts about our bunkers universe. The
2:18
Speaker 1: crazy things that happen all over the universe, from the
2:21
Speaker 1: cosmic scale of the large scale structure of the biggest
2:25
Speaker 1: things in the universe to how the tiniest things buzz
2:28
Speaker 1: around and work together to make you and me and
2:32
Speaker 1: ice cream. We take all that together, sprinkles on ants
2:35
Speaker 1: on top, and spoon feed it to you. Yeah, because
2:37
Speaker 1: the universe is crawling with anti particles, isn't it. It's
2:41
Speaker 1: mostly particles, but there are a lot of anti particles
2:44
Speaker 1: out there as well, that's true, and ants also in
2:47
Speaker 1: uncle's that's right. So those of us who are both
2:49
Speaker 1: physicists and art barks are very into those anti particles.
2:52
Speaker 1: What would you call a human art vark combination. It's
2:55
Speaker 1: not like a where of ark art man or art person.
3:00
Speaker 1: But it is an incredibly large and amazing universe, full
3:03
Speaker 1: of huge and almost hard to grasp phenomenon and exploding
3:08
Speaker 1: stars and supernovas and big black holes. But it's also
3:11
Speaker 1: filled with small phenomenon that it can also make you
3:14
Speaker 1: go wow and gasp and wonder. That's right. The mysteries
3:18
Speaker 1: of the universe are not just inside black holes or
3:21
Speaker 1: in the deep reaches of space or underground in billion
3:24
Speaker 1: dollar particle accelerators. They can also be found everywhere around you.
3:29
Speaker 1: It's possible to create things that physics hasn't quite yet
3:32
Speaker 1: figured out. With just a few hundred dollars of equipment
3:35
Speaker 1: in your garage. Yeah, and there are deep mysteries in
3:38
Speaker 1: terms of the particles and the very makeup of reality,
3:41
Speaker 1: but there are also sort of interesting miracles and mysteries
3:44
Speaker 1: in our everyday lives. We just look around. There are
3:47
Speaker 1: things that even professional art park physicists can explain. That's right,
3:51
Speaker 1: because physics is sort of a patchwork of different ideas.
3:55
Speaker 1: You know, the full universe, in all of its glory,
3:58
Speaker 1: is this incredibly complex, buzzing quantum soup of particles will
4:02
Speaker 1: never hope to understand. But the job of physics is
4:05
Speaker 1: to distill from that a few mathematical stories ideas about
4:09
Speaker 1: emergent phenomena, simplify things that we can pull out of
4:13
Speaker 1: this crazy chaos and tell little stories about. And sometimes
4:17
Speaker 1: those stories fit together, and sometimes we find things that
4:19
Speaker 1: fall between the cracks that can't really be described by
4:22
Speaker 1: any of the ideas that we have so far. Yeah,
4:25
Speaker 1: and it's pretty cool to talk about these because I
4:26
Speaker 1: feel like it opens people's eyes to the mystery that's arounds.
4:29
Speaker 1: And you know, once you find out there are mysteries
4:32
Speaker 1: in every corner of your house, and you sort of
4:34
Speaker 1: keep you an eye out after that to look for
4:36
Speaker 1: them and to have sort of an open eye for
4:38
Speaker 1: a wonder and awe. Yep. So when you go hunting
4:41
Speaker 1: for big physics mysteries, you don't have to bag yourself
4:44
Speaker 1: and elk. You can pick up tiny little ants around
4:46
Speaker 1: the house. So in this episode, we'll be talking about
4:49
Speaker 1: one particular interesting physics mystery or phenomenon that kind of
4:53
Speaker 1: involved all of the senses. It's tasty, it's tasty, and
4:57
Speaker 1: it feels good, but mostly involved a sigh and sound
5:01
Speaker 1: without any special effects. So to be on the program,
5:04
Speaker 1: we'll be talking about can sound turn into light? That
5:13
Speaker 1: sounds pretty cool, Daniel. It sounds illuminating. It does sound illuminating.
5:17
Speaker 1: And when I first heard about this, actually as a teenager,
5:20
Speaker 1: a high school student doing science reachers for the summer
5:23
Speaker 1: at Los Alimos National Labs, I thought it was bonkers.
5:26
Speaker 1: I thought it was crazy that you could turn sound
5:28
Speaker 1: waves into flashes of light. Frankly, I thought I was
5:31
Speaker 1: having my leg pulled. WHOA, So this has been a
5:34
Speaker 1: mystery since you were a grad student. That's a long time.
5:37
Speaker 1: Are you calling me old? I think you're calling me old, Well,
5:43
Speaker 1: your old alimal because I know we're the same age.
5:45
Speaker 1: That's true. You know, I was recently accidentally see seed
5:48
Speaker 1: on an email about me where I was described as
5:51
Speaker 1: a junior ish scientist. Oh interesting, that's good. Well, I
5:57
Speaker 1: guess it depends on who was calling you that. Was
5:59
Speaker 1: it a an older professor or like a hippon grad student.
6:03
Speaker 1: It was definitely a very senior professor. Yes, there you go. Yeah,
6:07
Speaker 1: I don't know how you should take that. I took
6:09
Speaker 1: it as a compliment, like the way I take everything.
6:11
Speaker 1: So you're a junior, that means there's still a lot
6:13
Speaker 1: ahead of you in terms of science. That's right. It's
6:15
Speaker 1: gonna be decades before I'm that old and crusty. But
6:17
Speaker 1: this has been a fascinating mystery since long before I
6:21
Speaker 1: was doing physics and long before I was born. This
6:24
Speaker 1: has been something of a mystery for almost a century
6:27
Speaker 1: since it was discovered. Yeah, and so it's a pretty
6:29
Speaker 1: fascinating phenomenon. And what's kind of cool is it? You know,
6:32
Speaker 1: it's not something that you need a billion dollar particle
6:34
Speaker 1: collider to explore or to see or to kind of
6:37
Speaker 1: try to figure out. It's something you can do and
6:39
Speaker 1: like your garage, right, for a few hundred bucks. Yeah,
6:41
Speaker 1: there are folks out there on YouTube that have instructions
6:44
Speaker 1: for how to make this happen. You get the right
6:46
Speaker 1: equipment and assemble it in a little bit of sophistication
6:49
Speaker 1: within a scilloscope, and you can create flashes of light
6:52
Speaker 1: from sound in your own garage. So the idea said
6:55
Speaker 1: you can turn sound into light, and so that happens.
6:59
Speaker 1: And there's a name for that phenomenon, right, that's right.
7:01
Speaker 1: It's a pretty cool name too. I'm curious to hear
7:03
Speaker 1: what you're going to think of it. It's called so
7:05
Speaker 1: No luminescence. It sounds like son of luminescence, like the
7:09
Speaker 1: sequel maybe too luminescence. I see luminescence. It's back and
7:14
Speaker 1: it's piste off. Yeah, it's fun once revenge now, So
7:18
Speaker 1: I guess that makes sense. Right. It's like sound, right,
7:20
Speaker 1: and the luminescence means that light. Yeah, it means glowing.
7:22
Speaker 1: It means Sonic glowing. So you know this is when
7:25
Speaker 1: you're playing Sonic the video game and you get that
7:27
Speaker 1: extra boost and Sonic starts to glow and your eyes
7:31
Speaker 1: get crossed from all the viatore game playing. But yeah,
7:34
Speaker 1: it's called so No luminescence and it's kind of an
7:37
Speaker 1: interesting phenomenon that apparently physicists can't explain quite fully. And
7:42
Speaker 1: so we were wondering how many people out there had
7:44
Speaker 1: heard of this term, this phenomenon and or have any
7:48
Speaker 1: ideas about what it could be. So Daniel went out
7:50
Speaker 1: there to the internet to ask people what is so
7:53
Speaker 1: no luminescence? And I'm still looking for more volunteers for
7:56
Speaker 1: people who are willing to play our game of answer
7:59
Speaker 1: wren them physics question without any preparation. It's fun, it's easy,
8:03
Speaker 1: it's no stress. If you'd like to participate, please write
8:07
Speaker 1: to me two questions at dandelion Jorge dot com. Yes,
8:10
Speaker 1: so think about it for a second. What do you
8:12
Speaker 1: think causes so no luminescence? Here's what people had to say.
8:16
Speaker 1: I've never heard of sono luminescence before. It sounds like
8:21
Speaker 1: something that has to do with both sound and light.
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Speaker 1: So maybe sound that somehow emits light, or maybe vice versa.
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Speaker 1: I've never heard of sono luminescence, but since so no
8:34
Speaker 1: implies sound, might it be that something lights up when
8:39
Speaker 1: you shoot sound waves at it? So something that causes
8:44
Speaker 1: light under the influence of sound. I know what luminescences,
8:47
Speaker 1: which is basically just when something gives off light. Find
8:50
Speaker 1: out what sonar is. But that sounds different to what
8:53
Speaker 1: sono means, So for that I have no idea. It
8:56
Speaker 1: must be something to do with sound and light, but
9:00
Speaker 1: I'm not sure what. I've never heard of sun no
9:02
Speaker 1: luminescence before, but I'm wondering by the name if it
9:07
Speaker 1: has to do with something glowing and sound, I look
9:13
Speaker 1: forward to learning. I know that luminescence is some kind
9:16
Speaker 1: of light um those neon color lights you having like
9:20
Speaker 1: parties or like paint people with. So no is sound,
9:26
Speaker 1: so I know that much. So I could, I would
9:29
Speaker 1: say that it has to do with sound and light,
9:32
Speaker 1: like how the photons are moving or changing for variations
9:37
Speaker 1: of sounds. I assume that this has something to do
9:39
Speaker 1: with light radiation or the afterglow that results from some
9:45
Speaker 1: form of heat concentration, like in a body or body
9:50
Speaker 1: of massive body. So no, like sound, luminescence like light.
9:55
Speaker 1: Maybe is that the way in which sound creates lights
10:00
Speaker 1: or something observable? I think there's so no luminescence is
10:04
Speaker 1: what happens when you vibrate something, maybe like a cloud
10:08
Speaker 1: in space, and it begins to glow. All right, some
10:12
Speaker 1: pretty interesting answers. A lot of people made the connection
10:14
Speaker 1: that it's sound and light. So kudos on the naming
10:17
Speaker 1: of this phenomena. I'm sorry, what did you say? I
10:19
Speaker 1: couldn't quite hear that. Can you repeat that? I said,
10:20
Speaker 1: you did a good job naming this physical fit off.
10:23
Speaker 1: I'm so glad I have that on tape and just
10:27
Speaker 1: copy and paste it every time. That's right. We did
10:29
Speaker 1: it once successfully, so we can now retire. That's right,
10:33
Speaker 1: It's possible. I guess that's how you go from being
10:35
Speaker 1: a junior physicist being junior ish. You accomplish something, you
10:39
Speaker 1: did it twice, you maybe get to junior certified. But
10:42
Speaker 1: people are right, this is a connection between sound and light.
10:46
Speaker 1: So even though nobody had actually heard of this specific phenomena,
10:49
Speaker 1: pretty much everybody guessed it just from the name. So
10:52
Speaker 1: good job everyone as all around. Yeah, and so this
10:55
Speaker 1: is not just the thing where you have sound and light.
10:57
Speaker 1: This is like how do you transform one type of
11:00
Speaker 1: energy or one type of phenomenon into another type of phenomenon,
11:04
Speaker 1: Like how do you go from sound to light or
11:07
Speaker 1: light to sound? And it's really kind of dramatic. You
11:10
Speaker 1: take these ingredients that you never imagine you could get
11:13
Speaker 1: them to glow, but you can create the conditions to
11:15
Speaker 1: create these incredible flashes of light. Yeah, so it's pretty
11:18
Speaker 1: cool effects. So let's dive into it, Daniel, what's like
11:21
Speaker 1: the basic experiment? How do you transform sound into light?
11:25
Speaker 1: The basic idea is to take a small container of water,
11:27
Speaker 1: get a bubble to form in that container, and then
11:31
Speaker 1: shake that bubble using sound waves. Remember, sound waves are
11:34
Speaker 1: basically compression waves. So every time I speak, that energy
11:39
Speaker 1: is transmitted and that information moves through the air because
11:42
Speaker 1: the molecules are pushing on the next molecules, which push
11:44
Speaker 1: on the next molecules, sort of like waves in traffic.
11:47
Speaker 1: And so if you shake that water using sound, and
11:50
Speaker 1: you do it adjust the right resonant frequency with the
11:53
Speaker 1: little bubble that you have in the center of the water,
11:55
Speaker 1: you can cause that bubble to expand and then collapse,
11:59
Speaker 1: and when it lapses, you get this bright flash of
12:02
Speaker 1: light that comes out of this bubble in your water. Wait,
12:05
Speaker 1: what so you have a little like a glass of water,
12:09
Speaker 1: I guess you when you put like speakers next to
12:11
Speaker 1: it or all around them, and then you basically send
12:14
Speaker 1: like vibrations into it, and they have to be kind
12:17
Speaker 1: of resonant or something right with the container. And if
12:20
Speaker 1: you have a bubble already in the water, then that
12:22
Speaker 1: bubble is gonna expand and then collapse suddenly. Yeah, And
12:26
Speaker 1: you can do it several ways. You can either create
12:28
Speaker 1: the bubble in advance and then make their resident frequency
12:31
Speaker 1: match the size of the bubble. Or if you have
12:34
Speaker 1: powerful enough sound, you can just start cranking up the
12:37
Speaker 1: sound waves and they will create their own bubbles. And
12:40
Speaker 1: then what happens is that those bubbles expand and collapse
12:43
Speaker 1: and you get this bright flash of light. It's very
12:46
Speaker 1: very brief. Wow. And I think it has to be
12:48
Speaker 1: supersonic sound, right, Like, it's not just like you know,
12:51
Speaker 1: turning on metallica and then you sudden like the water
12:54
Speaker 1: will glow. No, the sound doesn't have to be anything special,
12:57
Speaker 1: right The sound waves are not traveling that fast, not
12:59
Speaker 1: tiling supersonically in the water. I mean you do need
13:03
Speaker 1: sort of fairly high frequency. It's not just like you know,
13:06
Speaker 1: if you turn on a glass of water near a speaker,
13:08
Speaker 1: it's going to happen, but it's not like hypersonic. You
13:10
Speaker 1: can buy the equipment to generate these for you know,
13:13
Speaker 1: like a hundred bucks online. It's nothing that fancy. And
13:17
Speaker 1: so the bubble expands and then collapses. And then when
13:19
Speaker 1: it collapse that it actually it collapses so hard that
13:22
Speaker 1: it generates light. It generates light. Yes, you get this
13:26
Speaker 1: flash of light, and it's really incredible because you know,
13:29
Speaker 1: there's not that much energy in this sound. It's not
13:32
Speaker 1: like you're blastingness with this incredible amount of energy. But
13:36
Speaker 1: what comes out of the bubble? Are you v photons?
13:39
Speaker 1: I mean some of them are visible, so you can
13:41
Speaker 1: see them with the naked eye, but it extends up
13:43
Speaker 1: into the ultraviolet and ultra violet are very high energy photons.
13:49
Speaker 1: We know from like looking out into space that the
13:51
Speaker 1: temperature of things connects with the energy of the photons.
13:54
Speaker 1: They emit, you know, the Earth emits in the infrared
13:56
Speaker 1: and the Sun emits in the visual. And it takes
13:59
Speaker 1: like a super hot gas around black holes usually to
14:02
Speaker 1: generate ultra violet radiation in this significant amount. And so
14:07
Speaker 1: these tiny little bubbles in your garage are generating UV photons. Wow.
14:12
Speaker 1: And so it is it like one bubble it's going
14:15
Speaker 1: to blind you? Or is it like you need to
14:16
Speaker 1: see like a whole bunch of bubbles doing this at
14:18
Speaker 1: the same time to sort of see the actual glow. Well,
14:21
Speaker 1: you should always wear safety goggles anytime you do a
14:23
Speaker 1: physics experiment, especially one that involves a glass and sound,
14:26
Speaker 1: because it could shatter, but it's not dangerous. But the
14:29
Speaker 1: other incredible thing about it is that it doesn't just
14:31
Speaker 1: happen once. If you set it up, then the bubble
14:34
Speaker 1: emits light when it collapses, and then it recovers, and
14:36
Speaker 1: it does it again and again and again, and you
14:39
Speaker 1: can do it like extremely regularly, so you get a
14:42
Speaker 1: continuous source of these flashes. So you set this thing up,
14:45
Speaker 1: you can see it with your naked eyes in an
14:48
Speaker 1: undarkened room. Wow, Well, you won't see the bubble, right
14:52
Speaker 1: because the bubbles are super tiny, right. It's not like
14:54
Speaker 1: a giant bubble going exploding and expanding. It's like a
14:57
Speaker 1: Brazilian tiny little bubbles. You can't see the bubble with
15:00
Speaker 1: a naked eye because it's like a micrometer, But you
15:03
Speaker 1: can see the photons with your naked eye. Like what
15:05
Speaker 1: you will see is a glowing dot. And it depends
15:08
Speaker 1: exactly how you set it up. Until around thirty years ago,
15:10
Speaker 1: people were doing what you described, they would just like
15:13
Speaker 1: crash a bunch of sound into water and they would
15:15
Speaker 1: get a lot of little bubbles. But these days people
15:17
Speaker 1: are doing single bubble sun of luminescence. They create the
15:20
Speaker 1: bubble using some other technique. You just like put a
15:22
Speaker 1: drop of water or something to get a bubble in there,
15:24
Speaker 1: and then you can get a single bubble sitting at
15:26
Speaker 1: the center of your glass of water, and when you
15:28
Speaker 1: turn on the sound, it starts to glow. Like you
15:31
Speaker 1: can see YouTube videos of this all over the place.
15:33
Speaker 1: It's not that complicated and it's really visible, like you
15:36
Speaker 1: can definitely see this bubble glowing. Wow, that's crazy. I
15:40
Speaker 1: guess we'll get into it later. But you're making the error,
15:42
Speaker 1: or you're making the water molecules glow. Like. The amazing
15:45
Speaker 1: thing is that we don't really understand the physical process.
15:49
Speaker 1: It's like somehow you've created a super tiny little star
15:53
Speaker 1: trapped in the bubble inside a glass of water in
15:56
Speaker 1: your garage. And so people have spent a lot of
15:58
Speaker 1: time trying to understand exactly how this works, what happens,
16:01
Speaker 1: and whether it could possibly even be a way to
16:04
Speaker 1: do fusion on Earth to create sources of energy. Wow,
16:09
Speaker 1: sounds pretty cool, and you're telling me it's also pretty
16:12
Speaker 1: cool because it doesn't just happen in YouTuber's garages. It
16:15
Speaker 1: also happens in nature, Like there are animals he sort
16:18
Speaker 1: of do this and use this phenomena to defend themselves. Yeah,
16:21
Speaker 1: there are a few creators underwater that can create similar conditions,
16:25
Speaker 1: like the mantis shrimp and the pistol shrimp. They have
16:28
Speaker 1: these claws that can snap closed really really quickly, effectively
16:31
Speaker 1: giving acoustic energy to little bubbles that exist already in
16:35
Speaker 1: the water. So they create these little collapse and bubbles,
16:38
Speaker 1: and they do it not just because they want to
16:39
Speaker 1: create flashes of light, but because they want to shoot
16:41
Speaker 1: these bubbles. And so, for example, the pistol shrimp can
16:45
Speaker 1: shoot these tiny little bubbles at sixty miles that's a
16:48
Speaker 1: hundred kilometers per hour, and that kind of pressure can
16:51
Speaker 1: like kill a small fish. But at the same time,
16:54
Speaker 1: these bubbles also create sauno luminescence and so you can
16:58
Speaker 1: see like a tiny little flah of light. And when
17:00
Speaker 1: they do this, whoa, it's like a trimp with superpowers.
17:04
Speaker 1: It can shoot of light bullets. Yeah, and the biologists
17:07
Speaker 1: who work on that call this shrimpo luminescence. That sounds
17:12
Speaker 1: like the rice. It sounds like a delicious thing to
17:15
Speaker 1: have for lunch, you know, really make your stomach glow,
17:19
Speaker 1: bright up your day. It's a brilliant choice. Yeah, And
17:21
Speaker 1: so shrimp do it, and little critters do it, and
17:24
Speaker 1: you can do it in your garage. But it's still
17:26
Speaker 1: a big mystery to physicists. And so let's get into
17:29
Speaker 1: the physics of it and what could be happening there.
17:31
Speaker 1: But first let's take a quick break. All right, we're
17:46
Speaker 1: talking about shrimpo luminescence, which sounds like it's a nice
17:49
Speaker 1: snack like shrimp chips kind of, but they glow. That's right.
17:52
Speaker 1: They've tapped to that shrimp's proportional glowing ability. Oh I see,
17:56
Speaker 1: like maybe you got bit by one of these shrimps
17:58
Speaker 1: and now there's a superhero with that ability. But it
18:00
Speaker 1: would only work underwater, which is kind of a question
18:03
Speaker 1: that I had. Does this only work in the water
18:06
Speaker 1: or is it other liquids too. It does work in
18:08
Speaker 1: other liquids, for example, in sulfuric acid. It's even more powerful.
18:13
Speaker 1: But I do not recommend anybody get a container of
18:16
Speaker 1: sulfuric acid and try to do experiments with it. Then
18:18
Speaker 1: involved potentially shattering the glass or making it explode, So
18:22
Speaker 1: that's quite dangerous. But it's not limited to water, though
18:24
Speaker 1: most of the experiments have been done in water with
18:27
Speaker 1: varying amounts of various gases dissolved into it. Interesting, So
18:31
Speaker 1: is that a clue about what's going on? Like, it's
18:34
Speaker 1: not related to the actual water molecules. H two, but
18:37
Speaker 1: maybe it's something. But what these bubbles are doing. Yeah,
18:39
Speaker 1: people who are wondering for a long time about where
18:42
Speaker 1: the light is coming from. Is it coming from inside
18:45
Speaker 1: the bubble? Is it coming from the liquid just on
18:48
Speaker 1: the outside of the bubble. It's been something people have
18:50
Speaker 1: been wondering about for a long time. And this is
18:52
Speaker 1: something that's difficult, Like you might be wondering, like can't
18:55
Speaker 1: you just take a picture or like figure it out? Man,
18:58
Speaker 1: it's been going on for a hundred years. But it's
19:00
Speaker 1: hard because it's really tiny and it happens really really fast,
19:05
Speaker 1: and so getting like very accurate photography of what's going
19:09
Speaker 1: on is difficult. People use things like laser scattering to
19:13
Speaker 1: try to measure the size of this bubble as a
19:15
Speaker 1: function of time. So experimentally, it's quite challenging. You know,
19:20
Speaker 1: until like twenty or so years ago, people couldn't even
19:22
Speaker 1: reliably make single bubble son of luminescence, like create a
19:26
Speaker 1: bubble in a known location that you could like focus
19:29
Speaker 1: your cameras on to take pictures of. They were resorting
19:32
Speaker 1: to this like multi bubble luminescence, which makes it harder
19:36
Speaker 1: and harder. So we've sort of been making progress over
19:38
Speaker 1: the last hundred years just in like getting data for
19:41
Speaker 1: what is going on, not to mention than building models
19:45
Speaker 1: to explain interesting because you know, we have telescopes that
19:48
Speaker 1: can look at black holes and other galaxy at the
19:51
Speaker 1: center of other galaxies, and we have you know, my
19:53
Speaker 1: like microscopes that can look at basical media individual atoms.
19:57
Speaker 1: But you're saying, this is kind of hard to take
19:59
Speaker 1: a look at. It's difficult because of the speed. You know,
20:01
Speaker 1: the light that's emitted lasts for something like a hundred
20:05
Speaker 1: pico seconds, and so having cameras that are that high
20:08
Speaker 1: resolution is challenging. There are some measurements using streak photography
20:12
Speaker 1: that can get some information, but the best resolution it
20:15
Speaker 1: comes from laser scattering because you can shine lasers at
20:18
Speaker 1: these bubbles, and then the way the laser light bounces
20:21
Speaker 1: off depends, for example, on the size of the bubble
20:23
Speaker 1: at that time. So we do now have very precise
20:26
Speaker 1: measurements of the radius of the bubble as a function
20:29
Speaker 1: of time, so we can sort of see it collapsing.
20:31
Speaker 1: What we'd really like to know is like what's going
20:33
Speaker 1: on inside the bubble. What's the temperature of the gas
20:37
Speaker 1: or whatever is inside the bubble, And that's something we
20:39
Speaker 1: don't have direct measurements of. Interesting, So yeah, I think
20:43
Speaker 1: you sort of keyed into it is that's what's going
20:46
Speaker 1: on inside of the bubble, right, because inside of the
20:48
Speaker 1: bubble is what like water vapor, right, that's what these
20:51
Speaker 1: bubbles are made out of. Well, it depends a little
20:53
Speaker 1: bit on how you create the bubble, but we think
20:55
Speaker 1: initially it's water vapor or gas that evaporates then the
20:58
Speaker 1: inside surf of the bubble when it's created. So it
21:02
Speaker 1: depends a little bit on like what's dissolved into the water.
21:05
Speaker 1: You know, is there are gone or xenon trace amounts
21:07
Speaker 1: of that inside the water. But yeah, we think that
21:10
Speaker 1: essentially have a very low pressure bubble that's formed, and
21:13
Speaker 1: then the sound waves come along and they pump some
21:16
Speaker 1: energy into that it makes the bubble expand, or as
21:18
Speaker 1: you have this external pumping, that pushes the bubble out
21:22
Speaker 1: and it continues to expand because of its inertia while
21:25
Speaker 1: the pressure drops, and then eventually the water on the
21:28
Speaker 1: outside the pressure gets too great and it's like, hold on,
21:31
Speaker 1: we can't sustain this bubble any longer, and so it stops. Right.
21:34
Speaker 1: It grows from like, you know, a few microns to
21:37
Speaker 1: maybe ten microns, and then it stops and it collapses,
21:40
Speaker 1: It crashes down, and we think that probably what's happening
21:44
Speaker 1: is that that gas, that small amount of gas inside
21:47
Speaker 1: the bubble is getting very rapidly compressed. But again, the
21:50
Speaker 1: details of how that generates these photons is not something
21:53
Speaker 1: we yet understand interesting and it sounds like you don't
21:56
Speaker 1: even know what's inside of the bubble. It could be
21:58
Speaker 1: like a gas, or it could be like floating water molecules.
22:01
Speaker 1: We don't understand. And the reason that this has been
22:03
Speaker 1: a puzzle for so long this is for two reasons.
22:06
Speaker 1: One is it's hard to get data about what's going
22:08
Speaker 1: on exactly inside of it, and the other is that
22:10
Speaker 1: these conditions are really extreme, like we have some theories
22:14
Speaker 1: for how bubbles work, and we have theories for like
22:16
Speaker 1: how gas can emit light, and we have some theories
22:19
Speaker 1: for like what happens to a plasma. But most of
22:22
Speaker 1: these make assumptions, like they assume that the gas is
22:24
Speaker 1: in equilibrium, or you know, the bubbles are a certain
22:27
Speaker 1: size or whatever, and this phenomenon seems to sit like
22:30
Speaker 1: outside of all of where those stories should work. You know,
22:34
Speaker 1: it happens really really fast, and happens really really small,
22:37
Speaker 1: and the gas doesn't have time to relax and come
22:40
Speaker 1: into equilibrium. So all the sort of mathematical stories we've
22:43
Speaker 1: been building up and telling ourselves, this patchwork of physics
22:46
Speaker 1: we've built over the last few hundred years, this falls
22:49
Speaker 1: like right in the middle of them. And so if
22:51
Speaker 1: you try to like build a numerical simulation of what's
22:54
Speaker 1: going on, we just don't really have physical laws that
22:57
Speaker 1: can tell us what's happening unless you go way down
23:00
Speaker 1: to the individual particles. But it's impractical to simulate a
23:04
Speaker 1: bubble that has like ten to the ten particles and
23:07
Speaker 1: using individual particle physics. So sort of like fallen in
23:10
Speaker 1: this crack between our knowledge of how fluids work and
23:13
Speaker 1: how gases work at various temperatures. It's like it's too
23:17
Speaker 1: dynamic in a way, right, because physicists usually like to
23:20
Speaker 1: think about things once they're settled down, or like at
23:24
Speaker 1: the super duper particle level. But you're saying this is
23:26
Speaker 1: somewhere in between. It's somewhere in between, and we don't
23:28
Speaker 1: even know. For example, is this bubble a sphere? Is
23:31
Speaker 1: it symmetric or does it collapse asymmetrically, so like a
23:35
Speaker 1: first point on the bubble where the collapse starts to happen,
23:38
Speaker 1: sort of like the way a big rock will crack
23:40
Speaker 1: and they'll start in one place and then really split there.
23:43
Speaker 1: Or is it completely spherical? A lot of the calculations
23:46
Speaker 1: people have done assume a spherical bubble, and other people like, what,
23:49
Speaker 1: you can't assume a spherical bubble. It's obviously asymmetric, so
23:52
Speaker 1: that you know, shouting matches in the literature about how
23:55
Speaker 1: this might work. Do they use all caps when they
23:58
Speaker 1: shout in papers? This present is an idiot? If they
24:01
Speaker 1: can make that text blink, they would do that, you know,
24:03
Speaker 1: bright red and blinking wow. And it's kind of a
24:06
Speaker 1: big mystery because you're essentially taking the energy from sound
24:09
Speaker 1: waves and you're turning it into light. But that that's
24:12
Speaker 1: kind of weird, right, Like sound doesn't have enough energy
24:15
Speaker 1: to do that. Yeah, and there is sort of enough energy.
24:17
Speaker 1: It's about the energy density. Like sound waves have a
24:20
Speaker 1: good amount of energy, but you know, there's not a
24:23
Speaker 1: lot of energy in a very small space. And so
24:26
Speaker 1: if you talk about the energy density, then you need
24:29
Speaker 1: like a boost of a factor of ten to the twelve,
24:31
Speaker 1: like a trillion times more energy density to create UV
24:36
Speaker 1: photons from the energy in these sound waves. And so
24:40
Speaker 1: that's very impressive. Like these tiny little bubbles are like
24:43
Speaker 1: gathering the energy from the whole bubble and then compactifying
24:46
Speaker 1: it down really rapidly into a tiny spot that can
24:49
Speaker 1: release these high energy photons. Wow, that's pretty cool. So
24:53
Speaker 1: it's it's some sort of mysterious process. Well let's get
24:56
Speaker 1: into the mystery of it. But you were saying the
24:57
Speaker 1: key is the temperature of the bubble. Yeah, people really
25:00
Speaker 1: disagree about how hot it gets inside the bubble. You know,
25:03
Speaker 1: this is just normal water. You start with room temperature water,
25:07
Speaker 1: it's like thirty c you know, seventy degrees fahrenheit or whatever.
25:11
Speaker 1: You don't have to like heat this thing up. But
25:12
Speaker 1: what happens when you pump the sound waves into it
25:15
Speaker 1: is it grows and then collapses. And when the pressure increases,
25:18
Speaker 1: the temperature increases. Like, why is it hot inside the Earth?
25:22
Speaker 1: It's hot partially because of radioactivity K, but also because
25:25
Speaker 1: of crazy pressure. Why is it hot inside the sun?
25:28
Speaker 1: Because of crazy pressure? And you heat things up when
25:31
Speaker 1: you add pressure to them, and so people wonder, like
25:33
Speaker 1: how hot does it get in there? I mean when
25:36
Speaker 1: the bubble collapses, because when I imagine when the bubble
25:38
Speaker 1: is expanding, it gets sort of like a vacuum. It's
25:40
Speaker 1: super cold. But then when it collapses and compresses this gas,
25:43
Speaker 1: then it gets super hot. Yeah, And there's one guy
25:46
Speaker 1: with a crazy theory. He thinks that when the bubble expands,
25:49
Speaker 1: the gas freezes and turns into this like weird kind
25:52
Speaker 1: of ice, and then when the bubble collapses, it like
25:56
Speaker 1: cracks that gas and the electrons are sort of left
25:58
Speaker 1: behind and they're the ones emitting the light. Wait wait, wait, wait,
26:02
Speaker 1: what do you mean one guy with a crazy theory?
26:04
Speaker 1: Are you talking about a fellow physicist. I'm talking about
26:06
Speaker 1: a fellow physicists because there have been so many crazy
26:10
Speaker 1: theories about what's going on inside of this. Because it's
26:13
Speaker 1: been an open puzzle for so long, it's like a
26:15
Speaker 1: playground for people to have crazy, bonkers ideas. There's some
26:18
Speaker 1: people think it's like capturing the vacuum energy of quantum fields.
26:23
Speaker 1: All sorts of other crazy ideas have been battered around
26:27
Speaker 1: these days. The most likely explanations come down to a
26:30
Speaker 1: disagreement about whether when it collapses, does it form a
26:33
Speaker 1: plasma like what's going on inside the sun, or just
26:37
Speaker 1: a very very hot gas that then emits some light.
26:40
Speaker 1: Interesting because I guess gas by itself canna mid light, right,
26:44
Speaker 1: like fluorescent lighting, you just have a gas, it glows, right.
26:47
Speaker 1: I think fluorescent lighting is actually usually creating plasma and
26:50
Speaker 1: that plasma glows. But you're right that hot gas can
26:53
Speaker 1: also emit light, right. You don't have to be a plasma,
26:56
Speaker 1: And there's lots of ways for this to happen if
26:59
Speaker 1: you think about, like at the particle level, if you
27:01
Speaker 1: do have a plasma, then those things in midlight because
27:04
Speaker 1: a plasma, remember, is when things get hot enough that
27:07
Speaker 1: the electrons have so much energy that they're no longer
27:10
Speaker 1: captured by the nucleus. They're flying around free. And if
27:14
Speaker 1: you have an electron flying around free, it's going to
27:16
Speaker 1: get accelerated by all the atoms nearby it that now
27:19
Speaker 1: have a positive charge. And if you accelerate an electron,
27:23
Speaker 1: it will emit radiation, and that's photons. Every time an
27:26
Speaker 1: electron changes direction, every time it accelerates, it gives off
27:30
Speaker 1: a photon. So if it's a plasma, that's probably the
27:33
Speaker 1: process as a fancy German word called bremstrow lung, which
27:37
Speaker 1: means breaking radiation. So if it's a plasma, probably it's
27:40
Speaker 1: the electrons giving off this light. But other people have
27:43
Speaker 1: ideas that maybe it doesn't get hot enough to create
27:46
Speaker 1: a plasma and it's just like a really hot gas instead.
27:50
Speaker 1: Oh interesting, But I guess you're pretty sure that it's
27:52
Speaker 1: not like a chemical reaction, you know, like striking a
27:55
Speaker 1: match or something burning or something igniting, or you know,
27:58
Speaker 1: like materials that just kind of flash when you light
28:00
Speaker 1: them up. We're not sure, actually, because if it's not
28:02
Speaker 1: hot enough to make plasma, there's a whole variety of
28:04
Speaker 1: chemical reactions that can give off this kind of light.
28:08
Speaker 1: For example, could just be like water disassociation, you know.
28:12
Speaker 1: Either you could just be like pulling water molecules apart
28:14
Speaker 1: and smashing them back together. That's one theory that has
28:17
Speaker 1: this like asymmetric collapse, that these like jets of water
28:20
Speaker 1: are penetrating into the bubble asymmetrically, and when that happens,
28:24
Speaker 1: that's actually called fracto luminescence. This is a commonly known
28:28
Speaker 1: effect in solid state physics. When you're pulling apart and
28:31
Speaker 1: then reuniting things with charges, they can give off basically
28:34
Speaker 1: static electricity, little sparks. So that's one possibility. I mean,
28:38
Speaker 1: like you're pulling the two age of them oh apart
28:40
Speaker 1: and and that creates a spark. Yeah. Or it could
28:42
Speaker 1: be that, you know, water molecules bumping into each other
28:46
Speaker 1: can also give off light, you know, or you could
28:48
Speaker 1: just like excite the water molecule itself make it a
28:51
Speaker 1: little sort of internally hot because water molecules have lots
28:54
Speaker 1: of ways to vibrate into rotate, and they can absorb
28:58
Speaker 1: that energy and then they can give it off. So
29:00
Speaker 1: water itself can glow in even a liquid form. And
29:03
Speaker 1: so you know this it depends just on the temperature
29:06
Speaker 1: what's going on inside there. Interesting because I guess if
29:09
Speaker 1: it is plasma, then the light is more easily explained,
29:12
Speaker 1: Like if you have plasma, it's normal for plasma to
29:14
Speaker 1: just glow, right, Plasmas almost always glow. Yes, The trick is,
29:18
Speaker 1: how do you get a plasma? In order for that
29:20
Speaker 1: to happen, you need more than just compression. The calculations
29:24
Speaker 1: people have done suggest that for a plasma happen, what
29:27
Speaker 1: you need is like a super sonic shock wave. You
29:31
Speaker 1: need this bubble to collapse faster than the speed of
29:34
Speaker 1: sound in order to get the gas like compressed enough
29:37
Speaker 1: and hot enough in the short amount of time to
29:39
Speaker 1: become a plasma. That's something like you know what goes
29:42
Speaker 1: on inside a supernova, right, a supernova, you have a
29:45
Speaker 1: gravitational collapse that's racing faster than the speed of sound
29:49
Speaker 1: in that material. And so this shock wave is what
29:52
Speaker 1: gives you this incredible burst of energy from the supernova.
29:55
Speaker 1: So more than just like creating a tiny star inside
29:58
Speaker 1: a water bubble in your garage, you could be making
30:01
Speaker 1: like a tiny supernova in your garage. I was just
30:06
Speaker 1: sparking my cars, but apparently I've been wasting my garage
30:09
Speaker 1: space on too mundane things. Yeah, supernova factory right here,
30:15
Speaker 1: and yeah, I think you were saying, there are some
30:16
Speaker 1: clues about what's going on, Like we sort of have
30:18
Speaker 1: a rough idea of the temperature inside of these bubbles. Well,
30:21
Speaker 1: there is a lot of discussion about that because it's
30:23
Speaker 1: hard to measure it directly, and so what people do
30:26
Speaker 1: instead of, you know, putting a thermometer inside this tiny bubble,
30:29
Speaker 1: what they do instead is they look at the pattern
30:31
Speaker 1: of light that comes out. Because usually the pattern of light,
30:35
Speaker 1: the spectrum of light, like which frequencies are there in
30:38
Speaker 1: this light, gives you a clue about the temperature, just
30:41
Speaker 1: like the fact that I emit infrared radiation tells you
30:44
Speaker 1: that I'm not as hot as the sun, and the
30:46
Speaker 1: fact that the sun emits and the visible tells you
30:48
Speaker 1: it's not as hot as gases swirling around a black hole.
30:51
Speaker 1: So you can sort of invert that and say, what's
30:53
Speaker 1: the frequency of this thing? What temperature of object would
30:57
Speaker 1: give me light at that frequency? And when you do that,
31:00
Speaker 1: you get numbers like ten thousand degrees kelvin, which is
31:04
Speaker 1: like crazy hot. That's hotter than the surface of the
31:07
Speaker 1: sun inside of the little bubble, inside of this little
31:10
Speaker 1: bubble in your garage. Yeah, that's what we think though, right,
31:14
Speaker 1: that's what some people think. There are other disagreements. Other
31:16
Speaker 1: people measure different spectra that people have different conditions. Some
31:20
Speaker 1: people think that that's not a good model because that
31:23
Speaker 1: assumes that the gas is sort of sitting there and
31:25
Speaker 1: has time to thermalize and equalize, because this is thermal radiation.
31:29
Speaker 1: But the whole thing happens in you know, pico seconds.
31:31
Speaker 1: There's no time for that. So people think it's an
31:34
Speaker 1: inappropriate way to deduce the temperature because you know, what
31:37
Speaker 1: we're doing here is we're like trying to make analogies
31:40
Speaker 1: to what happens with other objects, the Earth, the Sun.
31:42
Speaker 1: But those things are very stable, right, They've been sitting
31:44
Speaker 1: around for a long time. They obey ideal gas laws,
31:48
Speaker 1: for example, whereas this tiny, little dynamic collapsing supernova in
31:52
Speaker 1: your garage, it's not necessarily true that the same rules apply.
31:56
Speaker 1: So you're a bit going out on a limb and
31:58
Speaker 1: making those assumptions. You're saying you can I you can't
32:00
Speaker 1: measure temperature because it's not steady or call. Yeah, maybe
32:03
Speaker 1: the frequency of light is not just determined by temperature
32:06
Speaker 1: in the same way as it is for other objects.
32:09
Speaker 1: And so some people think it's probably might be much colder.
32:12
Speaker 1: Other people think it might be much much hotter. Some
32:15
Speaker 1: people suspect it could even get up to millions of
32:18
Speaker 1: degrees kelvin inside that little bubble. And you're saying that
32:22
Speaker 1: these pulses these bubbles last for like pico seconds, which
32:25
Speaker 1: is also sort of a clue about what's going on.
32:27
Speaker 1: You know, one of the recent experimental breakthroughs was improving
32:30
Speaker 1: the timing of measuring of the light, and so we
32:33
Speaker 1: now know that these light pulses can last like fifty
32:37
Speaker 1: to a few hundred peco seconds, depending on you know,
32:40
Speaker 1: what gases you put in there. If you put zen
32:42
Speaker 1: on in there, for example, you get longer pulses. It
32:45
Speaker 1: depends a lot actually on how much zin, on how
32:47
Speaker 1: much are gone you have in there and dissolved in
32:49
Speaker 1: the water, dissolved in the water, because we think the
32:52
Speaker 1: gas in the bubble is evaporating from the surface of
32:55
Speaker 1: the bubble interior surface, And so it depends on what
32:58
Speaker 1: kind of stuff you have in the water, like if
33:01
Speaker 1: you get still water or mineral water. And a lot
33:04
Speaker 1: of the instructions for doing this, for example, suggest that
33:06
Speaker 1: you d gas your water first as much as possible
33:09
Speaker 1: and then put in a deliberate bubble, like make one bubble,
33:13
Speaker 1: and that way you'll get a single bubble asano luminescence
33:16
Speaker 1: instead of like lots of bubbles forming if you want
33:19
Speaker 1: to study in detail. But the clue came from measuring
33:21
Speaker 1: these pulses to be you know, order fifty to a
33:24
Speaker 1: hundred ish pico seconds, because the different theories for how
33:28
Speaker 1: you're getting this predicted different length pulses. And so for example,
33:32
Speaker 1: fracto luminescence, this idea of like asymmetric jets of water
33:36
Speaker 1: forming like these fingers into the bubble when it's collapsing,
33:40
Speaker 1: that would have like shorter pulses, and other theories people have,
33:43
Speaker 1: you know, make longer pulses. And so you know, the
33:45
Speaker 1: more data we get, the more we can sort of
33:47
Speaker 1: like narrow in on which theories are consistent with what
33:51
Speaker 1: we see. And you said, I can make this happen
33:53
Speaker 1: with other liquids, like sulfuric acid, But that's very different
33:56
Speaker 1: than water, right, it would be that maybe a totally
33:58
Speaker 1: different theory. But what's going on? Yeah, well, some of
34:01
Speaker 1: these theories can be simply extrapolated to sulfuric acid, and
34:04
Speaker 1: other ones not Some of them very dependent on the chemistry,
34:07
Speaker 1: but it does happen in sulfuric acid, and actually it's
34:09
Speaker 1: like much brighter if you use sulfuric acid. It's also
34:12
Speaker 1: dependent on the temperature, like a colder water gives like
34:16
Speaker 1: a hundred times brighter pulses than warmer water. Colder colder water, Yeah, exactly,
34:23
Speaker 1: I guess maybe the water is den sir, Maybe there's
34:25
Speaker 1: more energy in those waves. Yeah, so maybe the speed
34:28
Speaker 1: of sound is faster in colder water. Right, So the
34:30
Speaker 1: energy is transferred faster, and it depends a lot on
34:33
Speaker 1: the gases you use. So it's really sensitive to a
34:36
Speaker 1: lot of these details, which you know, gives you some
34:38
Speaker 1: clues as to what might be going on. And so
34:40
Speaker 1: what are the current theories about what's going on? Like
34:42
Speaker 1: are there quantum theories like at the particle level about
34:45
Speaker 1: what's going on? So the two most mainstream theories are
34:49
Speaker 1: either a shock wave model where you have this like
34:52
Speaker 1: supersonic compression into a plasma and then you have electrons
34:55
Speaker 1: radiating in this light, meaning like the bubble expands, it
34:59
Speaker 1: fills up with ass and then the sound wave around
35:02
Speaker 1: it causes it to crunch really fast, and that creates
35:05
Speaker 1: a plasma. That's the one theory, that's one leading theory.
35:08
Speaker 1: The problem is that nobody's ever seen this shock wave
35:11
Speaker 1: or the plasma directly, and the numerical simulations don't necessarily
35:14
Speaker 1: agree perfectly with what we actually see. The second leading
35:19
Speaker 1: theory is sort of a shock free compression model that says,
35:22
Speaker 1: when you take this gas, you squeeze it down against
35:25
Speaker 1: really hot and then it glows, but you don't actually
35:28
Speaker 1: get plasma. But it's not clear that that can generate
35:30
Speaker 1: enough light to explain what we see. So we have
35:34
Speaker 1: sort of two models, which you know, seem kind of
35:37
Speaker 1: reasonable but disagree a little bit in the story of
35:39
Speaker 1: what's going on, neither of which work perfectly. There's like,
35:42
Speaker 1: you know, a lot of holes there. People need to
35:44
Speaker 1: do some development. But then they're the fund models, the
35:47
Speaker 1: crazy model that suggests that something bonkers could be happening.
35:51
Speaker 1: There's another wild and crazy person out there with ideas. Yeah,
35:55
Speaker 1: because you know that's what theorists do. They find things
35:58
Speaker 1: that can't be explained and they say, maybe this is
36:00
Speaker 1: a clue, Maybe this is the thread that if I
36:03
Speaker 1: pull on, it is going to unravel everything we know
36:05
Speaker 1: about the universe. And you know, kudos to those people
36:08
Speaker 1: for being creative and trying to identify things. That's what
36:11
Speaker 1: happened with Einstein, right, He was trying to explain the
36:13
Speaker 1: photo electric effect, this experiment that nobody else could understand,
36:17
Speaker 1: and he developed quantum theory sort of accidentally along the way.
36:21
Speaker 1: So it's definitely well motivated. That was an experiment you
36:24
Speaker 1: could do in your garage to right, Yeah, exactly, you
36:26
Speaker 1: just you know, shine light on a piece of metal
36:28
Speaker 1: and measure the electrons. So I mean back then everything
36:31
Speaker 1: was a garage, right, Science was just garages back then. Well,
36:36
Speaker 1: now the garages have just gotten bigger. Now you can
36:38
Speaker 1: fit und cars in the large Hattern collider tunnel. That's right,
36:42
Speaker 1: Welcome to my ten billion dollar garage, Jay Leno, eat
36:45
Speaker 1: your heart out. Tony Stark would be proud. But there's
36:49
Speaker 1: this really fun theory about quantum radiation, and the idea
36:53
Speaker 1: is that maybe somehow this sono luminescence comes from like
36:57
Speaker 1: the equivalent of Hawking radiation, that you're somehow capturing the
37:02
Speaker 1: vacuum energy from the quantum fields. What remember that space
37:07
Speaker 1: We think is not just emptiness. We think it's this
37:10
Speaker 1: weird quantum fabric that everywhere in space has these quantum
37:14
Speaker 1: fields in it, a field being like the possibility for
37:17
Speaker 1: an electron or a photon to exist here. And you know,
37:20
Speaker 1: you can think of it like parking spaces or something.
37:22
Speaker 1: You know, it's the possibility for something to be there.
37:25
Speaker 1: But the weird thing about quantum fields is that even
37:27
Speaker 1: if there are no cars in the parking lot, there
37:29
Speaker 1: are no particles there, there's still energy there. Quantum fields
37:33
Speaker 1: can never be at zero energy. So even the emptiest
37:37
Speaker 1: space you can imagine has some energy in it. And
37:40
Speaker 1: we talk to the podcast about how maybe to tap
37:42
Speaker 1: into that or identify that or directly observe it, you know,
37:47
Speaker 1: to show that it's real with this weird experiment called
37:50
Speaker 1: the Casimir effect, where again you create a resonant cavity
37:54
Speaker 1: and what it does is it enhances some of those
37:56
Speaker 1: quantum zero point fields and it and it suppresses others,
37:59
Speaker 1: and doing so creates like a pressure differential. So you
38:02
Speaker 1: take these like too very thin plates and put them
38:05
Speaker 1: close together and you feel this weird, mysterious force on them.
38:08
Speaker 1: So people have been wondering maybe the quantum zero point
38:12
Speaker 1: energy is responsible for this, because maybe what's happening when
38:15
Speaker 1: this bubble collapses is that you are suppressing or enhancing
38:19
Speaker 1: various elements of this quantum field. And some guy did
38:22
Speaker 1: a calculation showing that, wow, maybe this can actually contribute
38:25
Speaker 1: it and explain it, and so that was kind of exciting.
38:28
Speaker 1: For a few years. I thought you were going to
38:30
Speaker 1: say that it's when the bubble expands and creates a
38:32
Speaker 1: vacuum that maybe like it pulls energy from the vacuum
38:36
Speaker 1: of the universe. Well, there is energy in every vacuum,
38:39
Speaker 1: but somehow turning that into real photons is the trick.
38:42
Speaker 1: And so people think that these photons are created when
38:45
Speaker 1: this bubble is collapsing, because it's like enhancing various modes,
38:49
Speaker 1: these very high energy modes of the vacuum inside the bubble.
38:53
Speaker 1: Like it's such a crazy collapse, it's actually like perturbing
38:56
Speaker 1: the quantum fields of the universe. Yeah, But then somebody
38:59
Speaker 1: else came along did another calculation and showed that for
39:02
Speaker 1: that to work, the bubble would have to collapse faster
39:05
Speaker 1: than the speed of light, so not just supersonic, but
39:08
Speaker 1: like super nominal. Well maybe I don't know, I guess not.
39:13
Speaker 1: So either, you've got to double down and be like yes,
39:16
Speaker 1: and I'm overthrowing relativity at the same time, or you're like,
39:19
Speaker 1: maybe this idea doesn't explain but happening. Maybe just need
39:22
Speaker 1: a better name, Like so no super luminism. There you go.
39:27
Speaker 1: All right, well it's still a big mystery. Let's get
39:30
Speaker 1: into what might be some interesting applications of what we
39:33
Speaker 1: might learn inside of these little bubbles. They might help
39:36
Speaker 1: solve our energy needs in the future. But first let's
39:39
Speaker 1: take another quick break. All right, we're we're talking about
39:54
Speaker 1: trimple luminate and still which I guess I'm still hung
39:59
Speaker 1: up on because it's tasty. Well, here's an experiment nobody's
40:02
Speaker 1: ever done. Is take a shrimp, put it inside one
40:05
Speaker 1: of these bubbles, and then put sound on and see
40:08
Speaker 1: what happens when you collapse the bubble on the shrimp.
40:10
Speaker 1: Or maybe this light inside of these tiny bubbles is
40:13
Speaker 1: created by tiny little shrimp shrimp patonstons, Yeah, or maybe
40:17
Speaker 1: we can get saun no shrimp lessons. Yeah, it will
40:20
Speaker 1: be a nice cocktail of physics. Now, but it's sort
40:23
Speaker 1: of interesting because I'm learning sort of recently that apparently,
40:27
Speaker 1: you know, plasma, is this a fourth state of matter?
40:29
Speaker 1: And it's kind of straightforward when you think about it,
40:32
Speaker 1: when you hear about it, but it actually it's still
40:33
Speaker 1: a big mystery to physicists about what's actually going on
40:37
Speaker 1: and what's happening and so in this case, and then
40:39
Speaker 1: maybe that's what's going on inside of these little bubbles,
40:42
Speaker 1: in which case they might teach us a lot about
40:44
Speaker 1: how to make fugion. Plasma is super fascinating and it's
40:48
Speaker 1: actually one of the most common states of matter in
40:50
Speaker 1: the universe, right because, like you can think about the
40:53
Speaker 1: Solar system, the Solar system is mostly the Sun, and
40:55
Speaker 1: the Sun is mostly plasma, so we think about liquid
40:59
Speaker 1: and water and gas because that's what's around us here
41:02
Speaker 1: in our neighborhood. But if you zoom out it's just
41:05
Speaker 1: a tiny a little bit and include the Sun, then
41:07
Speaker 1: the Solar system is mostly plasma. But plasma is extra
41:10
Speaker 1: tricky to understand because not only is it really hot,
41:14
Speaker 1: so the particles are moving around really fast, which means
41:17
Speaker 1: that every particle is affected by lots of other particles.
41:21
Speaker 1: Right Like in a solid as single atom is mostly
41:23
Speaker 1: affected by its immediate neighbors because nobody's moving very much.
41:26
Speaker 1: But in a plasma of particles are zooming around really fast,
41:28
Speaker 1: and so they're affected by lots of particles. So if
41:31
Speaker 1: you want to describe it numerically, do some calculations, then
41:34
Speaker 1: it takes a lot of different interactions to explain. And
41:37
Speaker 1: on top of that, not just are they moving fast,
41:40
Speaker 1: but everything is electrically charged. So you don't just have
41:43
Speaker 1: the speed of these particles and how they're bouncing into
41:45
Speaker 1: each other. You also have all these electric fields which
41:47
Speaker 1: cause magnetic fields, which cause electric fields. It's a real nightmare.
41:51
Speaker 1: There's a whole field called magneto hydro dynamics that tries
41:56
Speaker 1: to deal with this. And as you say, it's not
41:58
Speaker 1: something that we understand. Like you make a plasma and
42:00
Speaker 1: you put certain conditions on it, we can't always predict
42:03
Speaker 1: what's going to happen. You just got to get out
42:05
Speaker 1: there and build it and see what happens. Because the
42:08
Speaker 1: universe still has the prices for us. Yeah, And so
42:10
Speaker 1: what's cool about that is that if we can understand
42:13
Speaker 1: it and kind of control it, then we might be
42:15
Speaker 1: able to do what the Sun does here on Earth, right,
42:17
Speaker 1: We might be able to build fusion reactors that kind
42:19
Speaker 1: of do what the Sun does and and gives us
42:22
Speaker 1: energy forever. It's a long standing goal of physics. It's
42:25
Speaker 1: something that's been like ten years away for about fifty
42:28
Speaker 1: years now achieving fusion here on Earth. And as you say,
42:31
Speaker 1: the standard approach is to try to replicate what's happening
42:34
Speaker 1: in the Sun, which means get a bunch of hydrogen,
42:37
Speaker 1: heat it up really really hot. The problem is that
42:40
Speaker 1: the Sun is able to hold that together because if
42:42
Speaker 1: it's gravity, it's this huge blob of stuff and has
42:44
Speaker 1: enough gravity to hold itself together. We don't have that
42:47
Speaker 1: much hydrogen, so we need another way to hold it together,
42:50
Speaker 1: and so we use these magnetic bottles, and we talked
42:52
Speaker 1: about on the podcast recently there's this program in France
42:56
Speaker 1: called eater i t e R, which is aiming to
42:58
Speaker 1: build a fusion react to inside a magnetic bottle that
43:02
Speaker 1: might actually create energy, like a first working fusion reactor
43:05
Speaker 1: that could have like commercial prospects. That would be very
43:08
Speaker 1: exciting because you can use fuel like sea water to
43:12
Speaker 1: just get the hydrogen from there, and there's no radioactive
43:15
Speaker 1: waste and it's you know, essentially renewable and a single
43:19
Speaker 1: gram of fuel as as much energy as eighty thou
43:22
Speaker 1: tons of oil. So it would be really excellent. It
43:24
Speaker 1: would like transform our economy and our way of life.
43:28
Speaker 1: Electricity would be so cheap, it would be almost free,
43:30
Speaker 1: and we just need to give either some shrimpo luminifum.
43:34
Speaker 1: But it's difficult, right. Either is like a thirty forty
43:38
Speaker 1: billion dollar project. Now it's enormous, it's complicated. It's not
43:41
Speaker 1: easy to contain these things, and so people are always
43:44
Speaker 1: on the lookout for ways to make fusion happen that
43:47
Speaker 1: doesn't require enormous building sized magnetic bottles. So for a
43:52
Speaker 1: while people thought, hold lot of second, if we can
43:55
Speaker 1: create super hot, tiny dots of plasma in our garages,
43:59
Speaker 1: maybe we can us do fusion there. And people have
44:02
Speaker 1: thought for a long time that you don't necessarily need
44:04
Speaker 1: a sustained fusion reaction to make fusion happen. There's this
44:08
Speaker 1: whole other strategy for fusion where people just shoot like
44:12
Speaker 1: lasers at a dot of fuel and try to get
44:14
Speaker 1: it to implode and make fusion happen, like on the spot.
44:18
Speaker 1: So people thought, wait a second, maybe the same strategy
44:21
Speaker 1: will work, except instead of using lasers, were just using
44:24
Speaker 1: sound waves to make the thing implode and turn into
44:27
Speaker 1: a plasma. And fuse. Wow. Yeah, because you're saying maybe
44:30
Speaker 1: a theory about what's going on inside of these little
44:32
Speaker 1: bubbles is that there's maybe fusion going on right, like
44:35
Speaker 1: as the bubble collapses with so much pressure, maybe it's
44:39
Speaker 1: fusing things together. Was that one of the theories. Well,
44:41
Speaker 1: what happened is people tried to make fusion happen. They're like, well,
44:44
Speaker 1: let's instead of using water, let's use like heavy water
44:47
Speaker 1: that has deuterium in it, because deuterium is a good
44:50
Speaker 1: source of fuel for fusion. So they said, well, let's
44:53
Speaker 1: try to make it happen. And so there were a
44:55
Speaker 1: bunch of guys around fifteen twenty years ago who did
44:58
Speaker 1: a bunch of experiments and they actually claimed that they
45:01
Speaker 1: were achieving fusion. There was this experiment in two thousand
45:04
Speaker 1: and two that used deterium and heavy water and claimed
45:07
Speaker 1: to be generating a bunch of neutrons, which suggests that
45:10
Speaker 1: fusion was happening inside their little bubble. They called this
45:13
Speaker 1: bubble fusion, and that was very exciting because it's cheap,
45:17
Speaker 1: it's not complicated, and like you could build reactors almost
45:20
Speaker 1: trivially if that were true. But unfortunately, and the reason
45:24
Speaker 1: you don't have a sauno luminescence fusion reactor powering your
45:27
Speaker 1: electric car right now. Is that nobody could repeat that result. Interesting,
45:31
Speaker 1: So the idea way, the idea is that you would
45:33
Speaker 1: use sound waves to trigger fusion inside of heavy water,
45:38
Speaker 1: like basically the same experiment where you have like a
45:40
Speaker 1: cup of heavy water and then you put speakers and
45:43
Speaker 1: somehow that will you know, craze these these flashes that
45:46
Speaker 1: then you then capture that energy. Yeah, and in principle
45:48
Speaker 1: it's not outrageous because really all you need for fusion
45:52
Speaker 1: happen is really really high pressure. Remember the reason that
45:55
Speaker 1: fusion does just happen all the time is that two
45:58
Speaker 1: hydgen atoms don't really like each other. You know, they're
46:01
Speaker 1: both protons, and protons are positively charged. So to get
46:04
Speaker 1: them together close enough together for the strong force to
46:07
Speaker 1: fuse them, you have to overcome that coolumb repulsion, you know,
46:11
Speaker 1: the two positive charges disliking each other. So really all
46:14
Speaker 1: you need for fusion is take some source of fuel
46:17
Speaker 1: like deterium and compress it enough. And that's what sono
46:20
Speaker 1: luminescence is doing. It's like extraordinarily effective compression on a
46:25
Speaker 1: very short time scale. So in principle, you know, you
46:27
Speaker 1: might think it would work. The problem is that probably
46:30
Speaker 1: what's going on inside those bubbles gets you to like
46:33
Speaker 1: ten thousand degrees kelvin, but to get the fusion you
46:35
Speaker 1: really would need millions of degrees kelvin. So it's probably
46:39
Speaker 1: just not quite enough. Like the effect is enough to
46:41
Speaker 1: compress the heavy water, but it doesn't compress it enough
46:45
Speaker 1: to actually start fusing together. Yeah, it doesn't actually ignite
46:49
Speaker 1: into fusion. You can make a glow, which is you know, electromagnetism,
46:53
Speaker 1: but to actually get those nuclei together to overcome that
46:56
Speaker 1: repulsion so they fuse and create you know, energy from
46:59
Speaker 1: the strong force, that's a whole other magnitude. Can't you
47:02
Speaker 1: just get bigger speakers and you know what I mean, like,
47:05
Speaker 1: like what's the theoretical limit. Is it just that these
47:08
Speaker 1: bubbles or the physics of the heavy water molecules can't
47:12
Speaker 1: compress that much, or is it just that we haven't
47:14
Speaker 1: you know, they're to use big enough speaking. That's ry
47:18
Speaker 1: Nobody has played Metallica loud enough yet. That's the reason
47:22
Speaker 1: we haven't solved the image problem. The whole climate heavy
47:24
Speaker 1: metal for the heavy water. No, well, you asked a
47:26
Speaker 1: great question there, what's the theoretical limit. Knowing what the
47:29
Speaker 1: theoretical limit is requires understanding the theory, having a working
47:33
Speaker 1: model for what's going on, and we just don't. So
47:36
Speaker 1: you know, it's possible somebody could cook up a way
47:39
Speaker 1: to make this brighter. And there are people working on
47:42
Speaker 1: ways to make sono luminescence more intense. That's why they
47:45
Speaker 1: do it with sulphuric acid, or they dissolve zene on in,
47:48
Speaker 1: or they make it cold. But it's an experimental study
47:50
Speaker 1: because we don't have a working model for what's happening.
47:54
Speaker 1: So yes, somebody out there could say, hey, it turns
47:56
Speaker 1: out if you use this sound range, or if you
47:59
Speaker 1: add you know, detergent into your water or something, that
48:02
Speaker 1: it changes the conditions in a dramatic way and boost
48:05
Speaker 1: you up to levels where you might achieve you should
48:07
Speaker 1: that's still a possibility. Nobody's shown that happen yet so far. Well,
48:10
Speaker 1: it sounds like it's still kind of a big mystery
48:12
Speaker 1: about what's going on inside of these little bubbles, whether
48:15
Speaker 1: it's plasma or just the chemical reaction that's making these
48:18
Speaker 1: bubbles glow. And so I guess the question is how
48:20
Speaker 1: are we going to figure this out? Daniel? It sounds
48:22
Speaker 1: like it's been a mystery for decades, maybe even as
48:24
Speaker 1: far back as when you were a grad student. You know,
48:27
Speaker 1: when something like this sticks around in the physics community
48:30
Speaker 1: for so long and it's still a big mystery, like
48:33
Speaker 1: why don't people get on it and try to figure
48:35
Speaker 1: it out? People are on it, you know, people are
48:37
Speaker 1: studying it. And the way forward is to take better
48:40
Speaker 1: and better measurements so we get more precise details about
48:43
Speaker 1: what is happening, and that will let us resolve our
48:46
Speaker 1: theoretical models. You know, we need like to know what's
48:50
Speaker 1: happening so we can tell a better story about what
48:52
Speaker 1: makes it happen. And so we need, like experimentalists to
48:55
Speaker 1: come up with better ways to measure the temperature inside
48:58
Speaker 1: these bubbles and to take pictures of these collapsing bubbles
49:01
Speaker 1: with better and better resolution, so we can just get
49:04
Speaker 1: more information. You know, it's just like when you have
49:06
Speaker 1: a murderer and you haven't solved it, what do you do?
49:09
Speaker 1: You go pound the pavement for more clues. So we
49:11
Speaker 1: need more details, which allows to then weave together a
49:14
Speaker 1: story for what's happening. So it's really exciting because it's
49:17
Speaker 1: the kind of field where the experiments are leading the way.
49:20
Speaker 1: We see something we don't understand and we want to
49:22
Speaker 1: know more. I'm jealous of that because you know, like
49:25
Speaker 1: in particle physics, we see very little that we don't understand.
49:28
Speaker 1: We're always looking for something we don't understand. It's like
49:31
Speaker 1: decades between glimpses particles that we don't understand. So here's
49:34
Speaker 1: something like very concrete that we don't understand that you
49:38
Speaker 1: don't need a ten billion dollar experiment to recreate. So
49:42
Speaker 1: it's pretty exciting. Wow. So literally anyone can be in
49:45
Speaker 1: the cutting edge of this physics research. That's right, Go
49:48
Speaker 1: create supernovas in your garage, folks, But where eye protection.
49:50
Speaker 1: We have a theory that I think inside of these
49:52
Speaker 1: bubbles are a little tiny art vark and particles and
49:57
Speaker 1: that's my theory, and that's as good as every other theory.
50:01
Speaker 1: Yeah right, I'm at I know, as much as Stephen Hawkings.
50:04
Speaker 1: Yeah exactly, You're on the frontier for sure. But yeah,
50:06
Speaker 1: another great and awesome example of how there are mysteries
50:09
Speaker 1: even in our everyday lives. Like the next time you
50:11
Speaker 1: take a sip of water, think about the fact that
50:13
Speaker 1: there are mysteries inside of those little bubbles, and that
50:16
Speaker 1: if you hook it up some speakers, you could be
50:19
Speaker 1: doing physics research in your dining table and maybe even
50:22
Speaker 1: solve the climate crisis. All right, well, we hope you
50:24
Speaker 1: enjoyed that. Thanks for joining us, see you next time.
50:35
Speaker 1: Thanks for listening, and remember that Daniel and Jorge Explain
50:38
Speaker 1: the Universe is a production of I Heart Radio. For
50:41
Speaker 1: more podcast for my heart Radio, visit the i heart
50:44
Speaker 1: Radio app, Apple Podcasts, or wherever you listen to your
50:48
Speaker 1: favorite shows. Yea ye,