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Did the XENON experiment just discover a weird axion? · Daniel and Kelly’s Extraordinary Universe

0:08
Speaker 1: Hey, Daniel, did you guys find dark matter yet? Uh?
0:11
Speaker 1: Not yet? Still looking It's been what a few decades,
0:15
Speaker 1: embarrassingly more than a few. I'm just wondering, you know,
0:17
Speaker 1: are you sure you're doing it right? Well, you know,
0:21
Speaker 1: I think we're doing our best, but there's always a
0:23
Speaker 1: chance were messing it up. Just asking because you know,
0:25
Speaker 1: maybe it's time to bring in some engineers to take
0:28
Speaker 1: over and help you out. Oh yeah, we could use
0:31
Speaker 1: a few cartoonists. Maybe lighten the mood over there. See,
0:35
Speaker 1: you need someone to make light of dark matter. H
0:54
Speaker 1: I am more handmade cartoonists and the creator of PhD comics. Hi.
0:57
Speaker 1: I'm Daniel Whitson. I'm a particle for exist and I'm
1:01
Speaker 1: desperately seeking dark matter. Sounds like a movie from the eighties,
1:05
Speaker 1: Desperately seeking dark Matter. I hope it is, because in
1:07
Speaker 1: the end of those movies, they always find what they're
1:10
Speaker 1: looking for. So that means that in about two hours,
1:13
Speaker 1: I'll discover dark matter. There'll be some ups and downs,
1:16
Speaker 1: but in those movies they don't always find what they
1:18
Speaker 1: were expecting. That's true. Sometimes it turns out the friends
1:21
Speaker 1: they made along the way are the real dark matter. Anyways,
1:26
Speaker 1: Welcome to our podcast, Daniel and Jorge Explain the Universe,
1:30
Speaker 1: a production of My Heart Radio, in which we take
1:32
Speaker 1: you on a wrong calm journey throughout the entire universe,
1:36
Speaker 1: hoping you'll fall in love with the biggest mysteries and
1:38
Speaker 1: the smallest mysteries, the craziest things that are out there.
1:41
Speaker 1: Because the curiosity of scientists is your curiosity. The things
1:45
Speaker 1: you wonder about are the things that scientists today are
1:48
Speaker 1: still trying to understand. Yeah, and sometimes we cover not
1:51
Speaker 1: just the science itself, but when scientists discover something new
1:55
Speaker 1: and how they went about doing it. That's right in.
1:57
Speaker 1: My favorite version of these stories is when somebody build
2:00
Speaker 1: something new to look for something a and then they
2:03
Speaker 1: accidentally stumble across something totally different, which blows their minds
2:07
Speaker 1: and changes our understanding of the universe. Those are my
2:10
Speaker 1: favorite stories. That happens a lot, like you're looking for
2:12
Speaker 1: one thing, but you discover something else. That happens almost
2:15
Speaker 1: every time we turn on a new kind of eyeball
2:18
Speaker 1: to the universe. Universe is so filled with surprises that
2:22
Speaker 1: every time we create a new technology that lets us
2:25
Speaker 1: listen to the universe or look at the universe in
2:27
Speaker 1: a new way, we see something weird. You know, you've
2:30
Speaker 1: got the cosmic microwave background radiation, this small hiss of
2:34
Speaker 1: background noise that filled the antenna in New Jersey that
2:38
Speaker 1: those guys were definitely not looking for, but ended up
2:41
Speaker 1: being pretty good evidence for the Big Bang. You've got
2:44
Speaker 1: particles discovered here and there when nobody was expecting them.
2:47
Speaker 1: Every time we turn on a new telescope, we see
2:50
Speaker 1: some new kind of star or galaxy or black hole
2:52
Speaker 1: or weird stuff that we didn't expect. Right, it's a
2:54
Speaker 1: wonderful experience. And what's the standard protocol? Do you, like,
2:58
Speaker 1: pretend you weren't looking for a and you are looking
3:00
Speaker 1: for being out the whole time, or do you pretend
3:02
Speaker 1: that it was all part of the you know, master plan. No,
3:05
Speaker 1: it's the best kind of discovery, the unanticipated discovery. As
3:09
Speaker 1: an experimentalist, you're not interested in going to find what
3:12
Speaker 1: somebody else predicted because then hey, they get the Nobel Prize.
3:15
Speaker 1: It was really their idea. You're just checking the box.
3:18
Speaker 1: You're an experimentalist if you want to be an explorer,
3:20
Speaker 1: if you want to go out in the universe and
3:22
Speaker 1: discover something new, and so yeah, you're gonna, you know,
3:25
Speaker 1: follow the map and get ideas from the theorists. But
3:28
Speaker 1: the fantasy is to find something weird, something new, which
3:31
Speaker 1: changes are very understanding of the universe, and so frankly,
3:35
Speaker 1: there's a bit of sometimes an overreaction like, hey, I
3:38
Speaker 1: found something I don't understand. Maybe it's a crazy new discovery. Yeah,
3:42
Speaker 1: I'm sure mcgillan and lucent Clark and all those explorers
3:44
Speaker 1: would often say, whoops, what's this? Maybe it's dark matter
3:49
Speaker 1: in the anachronistic science fiction time travel movie that I'm
3:52
Speaker 1: pitching Netflix. That's totally a scene. Is it a romantic
3:55
Speaker 1: comedy as well? Of course everything has to be a
3:58
Speaker 1: wrong comedy days. That's right, it's a Marvel formula, that's right,
4:04
Speaker 1: dark matters of dark matter. But anyway, we're talking today
4:06
Speaker 1: about one such experiment that was looking for one thing
4:10
Speaker 1: and may have accidentally or inadvertently found something else, maybe
4:15
Speaker 1: of more importance. That's right. This is an experiment that
4:19
Speaker 1: released their results a few weeks ago, and we got
4:21
Speaker 1: questions from listeners about what does this mean? And it's
4:24
Speaker 1: also made a real buzz in the particle physics community.
4:28
Speaker 1: Here's examples of what some prominent particle physicists said. Neil Weiner,
4:32
Speaker 1: a dark matter of physicist at n y U, said,
4:34
Speaker 1: I'm trying to be calm here, but it's hard not
4:36
Speaker 1: to be hyperbolic. If this is real, calling it a
4:39
Speaker 1: game changer would be an understatement. Yeah, so people got
4:44
Speaker 1: pretty excited about this, and then that is pretty hyperbolic.
4:47
Speaker 1: Mike Turner, famous physicist at U Chicago former head of
4:51
Speaker 1: the NSF, said quote, I really want to believe it,
4:54
Speaker 1: but I think it will probably break my heart. Just
4:57
Speaker 1: like a good romantic comedy. It's X you in it
5:00
Speaker 1: makes you fall in love with it, and then it crushes.
5:04
Speaker 1: So there's a lot of buzz about this. Huh. People
5:06
Speaker 1: are tentatively excited. People are tendively excited. They want this
5:10
Speaker 1: to be something new, something fantastic, something fundamental. On the
5:14
Speaker 1: other hand, of course, it could just be nothing. It
5:17
Speaker 1: could be the experiment list don't quite understand what their
5:20
Speaker 1: machine is doing. So all these professional, prominent particle physics
5:23
Speaker 1: professors are pausing their expectations. Well, you know, they are
5:29
Speaker 1: pretty particular about claiming discovery, so you have to you
5:33
Speaker 1: have to really cross the threshold before people believe you've
5:35
Speaker 1: found something new. All right, so Tody on the podcast,
5:38
Speaker 1: we'll be asking the question, did the Zenon Experiment just
5:46
Speaker 1: discover an axion? Now that's a lot of x is
5:50
Speaker 1: in for one sentence. There's a lot of xs and
5:52
Speaker 1: a lot of non axion. Those are two words which
5:56
Speaker 1: sounds sound pretty sign See, you know, the X just
5:59
Speaker 1: kind of pushes a over that's right, you know. And
6:01
Speaker 1: the Xon experiment is pretty cool. It's actually well named
6:04
Speaker 1: because basically it's a huge tub of zenon and it's
6:07
Speaker 1: sitting in a mine underground in Italy looking for dark matter,
6:11
Speaker 1: and everybody's been waiting to hear what it says, like
6:14
Speaker 1: will it find dark matter? And so it was already
6:17
Speaker 1: an exciting moment for particle physics when we knew they
6:20
Speaker 1: were going to announce their results, and so everybody was
6:23
Speaker 1: pretty surprised at what they ended up announcing. But anyways,
6:26
Speaker 1: we were wondering, as always, how much of this incredible
6:30
Speaker 1: potential discovery had made it out there to the public.
6:33
Speaker 1: Aware people are about this question, and so Daniel, as
6:37
Speaker 1: usually went out there into the wild with the Internet
6:39
Speaker 1: to get people's reactions to the question, did the Zenon
6:42
Speaker 1: Experiment just discover an axio? That's right, and if you're
6:46
Speaker 1: interested in participating in our virtual person on the street
6:49
Speaker 1: interviews and lending your speculation to our podcast, please write
6:53
Speaker 1: to us two questions at Daniel and Jorge dot com.
6:56
Speaker 1: We're always looking for and welcoming volunteers. Think about it,
6:59
Speaker 1: ourse A, Can do the words Zenon and Axion mean
7:02
Speaker 1: anything to you? If someone ask you this question, Here's
7:06
Speaker 1: what people had to say. I have no idea what
7:08
Speaker 1: an actually, honest, but I do know that Xenon experiment
7:12
Speaker 1: has to do something with finding dark matter. I have
7:16
Speaker 1: no idea what the Zenon experiment is. I have no
7:19
Speaker 1: idea what actions are. Just listen to that fascinating episode
7:22
Speaker 1: this week. However, I have not heard about this one either.
7:27
Speaker 1: I'm not entirely sure, but I don't think so. The
7:30
Speaker 1: word Zenon just reminds me of zena warrior princess, so
7:33
Speaker 1: I have no idea what that is. Honestly, I thought
7:36
Speaker 1: until we're just making computer hardware, not physics experiments. But
7:40
Speaker 1: what do I know? Maybe the third new scene on
7:42
Speaker 1: CPUs have somehow discovered a deep truth of the universe.
7:46
Speaker 1: I have no idea of what either of them is.
7:49
Speaker 1: But whenever we hear statements in science with a question
7:52
Speaker 1: mark in the end, then the answer is most likely no.
7:56
Speaker 1: All right, I'm with the person who said it sounds
7:58
Speaker 1: like Zena the Warrior Princess. I bet she made a
8:01
Speaker 1: lot of discoveries in her time. You know, she was
8:04
Speaker 1: an explorer for sure, and a trailblazer. How to slice
8:07
Speaker 1: the person in half in one swoop. I think she
8:10
Speaker 1: destroyed the dark crystal at some point in maybe in
8:12
Speaker 1: one episode. I think you're crossing your universes. There is
8:15
Speaker 1: there a dark crystal, and well, I was a little
8:18
Speaker 1: surprised that none of our listeners had heard of this
8:21
Speaker 1: result in science, because it was on the New York
8:23
Speaker 1: Times and all sorts websites, and definitely a few listeners
8:26
Speaker 1: wrote in to ask us. But I guess it hadn't
8:29
Speaker 1: penetrated as deeply as I thought. So this maybe the
8:32
Speaker 1: first time you're hearing about this fascinating result, in which
8:35
Speaker 1: case I'm glad that we get to explain it to you. Yeah,
8:38
Speaker 1: was it like front pages of New York Times or
8:40
Speaker 1: you know, there's kind of a lot going on these days.
8:43
Speaker 1: There is a lot going on these days. I don't
8:45
Speaker 1: get the New York Times physical copies, so I can't
8:47
Speaker 1: really tell how prominently it is. And I definitely dig
8:50
Speaker 1: down to read the science underneath all the crazy politics
8:53
Speaker 1: and medical pandemic news, just to sort of escape that
8:56
Speaker 1: crazy university, just to kind of sorbe or your pellette
9:00
Speaker 1: a little bit. Also, it's your profession, and I'm curious
9:04
Speaker 1: and I'm hoping that they will discover it. And I
9:05
Speaker 1: heard about it professionally. Also, you know through particle physicists
9:09
Speaker 1: that something exciting was coming, and so I was waiting
9:12
Speaker 1: to hear about this result. And by that you mean Twitter.
9:14
Speaker 1: You heard it on Twitter. I'm not going to give
9:16
Speaker 1: away are totally secret mechanisms for communicating important important scientific
9:22
Speaker 1: advance scientific it probably is secret because nobody's following you.
9:30
Speaker 1: Just kidding, all right, So let's get dig into it. So, Daniel,
9:34
Speaker 1: potentially amazing and groundbreaking and world turning result has just
9:39
Speaker 1: been found in an experiment in this world recently a
9:42
Speaker 1: few weeks ago. So step us through it. What is
9:45
Speaker 1: the Zenon experiment? First of all, so the Zenon experiment
9:48
Speaker 1: is basically a huge tub of zenon, cooled down, sitting underground.
9:54
Speaker 1: And you might wonder, like, why would you want to
9:56
Speaker 1: do that. Who would want to chill a bunch of
9:58
Speaker 1: zenon down to very cold temperatures? And the reason is
10:01
Speaker 1: that it's looking for a very shy particle. It's hoping
10:05
Speaker 1: to spot one particle of dark matter flying through the
10:08
Speaker 1: Earth and banging into one of these zenon atoms. Interesting,
10:12
Speaker 1: so it's a paint a picture for us. How big
10:14
Speaker 1: of a tub are we talking about? Is it like
10:16
Speaker 1: a pool or is it like a bathtub or is
10:19
Speaker 1: it more like a bucket. It's like a really big bucket,
10:22
Speaker 1: maybe like a hot tub size. I mean, xenon is
10:24
Speaker 1: pretty heavy stuff. Is this is about three metric tons
10:28
Speaker 1: of zenon and so you know it's about as tall
10:31
Speaker 1: as a person and maybe a meter in diameter, and
10:35
Speaker 1: so you know it's enough to like flash freeze Han Solo.
10:38
Speaker 1: Probably now we're talking language, I can understand any And
10:42
Speaker 1: that was definitely a wrong com. I mean, if Star
10:44
Speaker 1: Wars is not a wrong com, I don't know what is.
10:46
Speaker 1: I know exactly exactly. Anyway, this Xenion experiment was not
10:50
Speaker 1: trying to you know, capture and freeze people who are
10:54
Speaker 1: on the run from interstellar bounty hunters. Instead, it was
10:57
Speaker 1: trying to capture a signal of dark matter, this stuff
11:00
Speaker 1: that fills the universe, but so far has been frustratingly
11:04
Speaker 1: invisible to us. Let's see and why zenon. Xenon is
11:07
Speaker 1: one of the noble gases, right, that's right, it's one
11:10
Speaker 1: of the noble gases. And we use xenon because if
11:12
Speaker 1: dark matter bumps into something, it's going to be a
11:14
Speaker 1: very small signal. And so what we want is a
11:17
Speaker 1: very big pile of very quiet matter that otherwise isn't
11:21
Speaker 1: doing anything, so that if we get a little signal
11:23
Speaker 1: of dark matter comes in and happens to bump into
11:26
Speaker 1: one of these nuclei, we can tell if you just
11:28
Speaker 1: got like a huge tub of hydrogen as all sorts
11:31
Speaker 1: of crazy stuff going on all the time, and if
11:33
Speaker 1: dark matter comes in and bumps the hydrogen atom, you
11:35
Speaker 1: wouldn't even notice. But a big pool of xenon and
11:38
Speaker 1: just sitting there mostly does nothing. And so something is
11:42
Speaker 1: able to penetrate a mile underground and bump into one
11:45
Speaker 1: of these xenon atoms, then you might notice it's pretty chill.
11:49
Speaker 1: It doesn't, I guess it's it's cold, so it's not moving,
11:52
Speaker 1: and it's also not very reactive. I guess that's what
11:54
Speaker 1: you're saying exactly, And that's why we use these noble gasses.
11:57
Speaker 1: Other teams were thinking about using liquid are Gone, for example,
12:00
Speaker 1: But Zeno really has the best combination of being available,
12:03
Speaker 1: not being crazy expensive, and giving off the right kind
12:06
Speaker 1: of signal when it does get bumped, and it also
12:09
Speaker 1: fit the acronym better exactly. And that's how we make
12:13
Speaker 1: these choices. Really. In the end, it's it's about the
12:15
Speaker 1: r It would have been awkward if the Zenon experiment
12:18
Speaker 1: use our gun when it is maybe nobody who had
12:20
Speaker 1: to know. It could be a big cover up. You know,
12:22
Speaker 1: this is Xenon gait. It's all covered up anyways. Yeah,
12:26
Speaker 1: And you know, we build this device because we're looking
12:28
Speaker 1: for a particular thing. We know that dark matters out there.
12:32
Speaker 1: We know that it has its matter that has gravity,
12:34
Speaker 1: that's some kind of stuff, but we don't really know
12:37
Speaker 1: very much else about it. We hope that it also
12:40
Speaker 1: can do something else, That is, that it can bump
12:42
Speaker 1: into normal matter and sometimes interact with it. We're using
12:45
Speaker 1: some sort of force that's not grab We know dark
12:48
Speaker 1: matter doesn't feel electromagnetism, so it can't be that force.
12:51
Speaker 1: We know it doesn't feel the strong force. We know
12:54
Speaker 1: it doesn't feel a weak force. If it felt one
12:56
Speaker 1: of those forces, we would have seen it already. So
12:58
Speaker 1: we're hoping, beyond hope that it also has some new
13:02
Speaker 1: kind of dark force and it can use that to
13:04
Speaker 1: bump into normal matter. Interesting, and we don't know that
13:07
Speaker 1: it does. It's just a guess. It's just a hope.
13:09
Speaker 1: It's like, well, if it is this thing and it
13:11
Speaker 1: has this new force, then maybe we could see it
13:13
Speaker 1: this way. So Zenon, this experiment really is built on
13:17
Speaker 1: sort of a lot of assumptions, like let's build the
13:19
Speaker 1: kind of thing that could see this very particular kind
13:22
Speaker 1: of particle. You could be wrong, like it could be
13:24
Speaker 1: that maybe dark matter only interacts through gravity, in which
13:28
Speaker 1: case even this giant tub of Xenon wouldn't see it,
13:31
Speaker 1: or interact with it or catch it exactly. We have
13:34
Speaker 1: only very weak arguments to suggest that dark matter is
13:37
Speaker 1: a particle and that it can interact with normal matter
13:40
Speaker 1: in any way other than gravity. We've never seen it.
13:42
Speaker 1: We've certainly I've never proven that it can interact non gravitationally.
13:46
Speaker 1: We're just sort of hoping it does, because if it doesn't,
13:48
Speaker 1: we have no chance at ever figuring out what kind
13:51
Speaker 1: of particle it is, because gravity is so weak that
13:55
Speaker 1: you can only use it to study like enormous galaxy
13:58
Speaker 1: sized blobs of dark matter. So we're hoping it's there,
14:01
Speaker 1: and you know, in particle physics we often play the
14:03
Speaker 1: game of finding a negative result, Like if we build
14:06
Speaker 1: this thing and we don't see it, that means, hey,
14:09
Speaker 1: if dark matter is a particle it doesn't have this
14:11
Speaker 1: kind of interaction, we can still learn something about what
14:14
Speaker 1: dark matter doesn't do. It's not nearly as exciting, but
14:17
Speaker 1: you know, it's still new territory scientific You're still checking
14:20
Speaker 1: a box and hoping to get a clearer picture. Yeah, exactly.
14:23
Speaker 1: But you know, sometimes you build this device to look
14:25
Speaker 1: for one very particular kind of particle and it spots
14:29
Speaker 1: something else. You know, in some sense, it's very specific.
14:32
Speaker 1: It's looking for this kind of particle, a whimp, a
14:34
Speaker 1: weekly interacting massive particle that we think dark matter might be.
14:38
Speaker 1: But on the other hand, it's just a very sensitive,
14:41
Speaker 1: very quiet detector that could notice some other weird new
14:45
Speaker 1: thing flying through the game. So it's kind of a
14:47
Speaker 1: last attempt at trying to feel or touch dark matter.
14:50
Speaker 1: Because if it doesn't work, then it tells you that
14:53
Speaker 1: maybe we'll never interact with dark matter. Yeah, and this
14:56
Speaker 1: is sort of the like seventh step in the succession
14:59
Speaker 1: of the detectors. They started with a very small little
15:02
Speaker 1: container of zenon just to see if it worked, and
15:05
Speaker 1: it did, but the smaller amount of zeno and you have,
15:07
Speaker 1: the less sensitive you are. So then they scaled up,
15:09
Speaker 1: and they scaled up and they scaled up, and this
15:11
Speaker 1: is the first time they've had a detector that's like
15:14
Speaker 1: more than a ton of zenon. And as they were
15:17
Speaker 1: running this one, their simultaneously building a bigger one. And
15:20
Speaker 1: the reason is that you want to run longer and
15:22
Speaker 1: you want more zenon because that gives you more chances
15:25
Speaker 1: to find it. So this is like xenon x L,
15:30
Speaker 1: and now they're thinking about zenon x x L. Yeah,
15:33
Speaker 1: this is xenon one ton, and pretty soon they're coming
15:36
Speaker 1: with zenon n ton, which means like several tons of zeno.
15:40
Speaker 1: And then there's competition. There's one in the US called
15:43
Speaker 1: l Z and another one in China called Panda X,
15:46
Speaker 1: and everybody's racing to build the biggest amount of zenon
15:49
Speaker 1: and who has the coolest name for their device definitely
15:53
Speaker 1: panneda x wins that one. All right. So the idea
15:55
Speaker 1: is that you have this tub of zenon. It's chill,
15:58
Speaker 1: it's not very reactive. And the scenarios and maybe a
16:01
Speaker 1: dark matter particle will come in and bump into a
16:04
Speaker 1: xenon atom and then what like move it or cause
16:08
Speaker 1: it to flash or wiggle? What's the what's the scenario
16:11
Speaker 1: under which you might detect dark matter? Yes, so we're
16:14
Speaker 1: not terribly sensitive to it. All we can see is
16:16
Speaker 1: depositions of energy, Like a particle comes in and bumps
16:20
Speaker 1: the xenon. We can't see the particle that came in
16:22
Speaker 1: at all. All we can see is that the nucleus recoiled,
16:25
Speaker 1: like the xenon got pushed a little bit, and as
16:28
Speaker 1: you said, it deposits some energy. And what it makes
16:31
Speaker 1: is that the xenon absorbs that energy from the little
16:34
Speaker 1: push and then it gives it off again. It doesn't
16:36
Speaker 1: like to hold onto it, so it usually gives off
16:38
Speaker 1: a little photon, gives off a little flash of light.
16:41
Speaker 1: And so this is one reason why we choose zen on.
16:43
Speaker 1: It has really nice scintillation profits. Basically, you excite any
16:47
Speaker 1: of the zenon atoms and they form a little molecule
16:51
Speaker 1: pairs of zenons. Those are excited like wiggling back and forth,
16:54
Speaker 1: and then they relax back down to two individual xenon
16:57
Speaker 1: atoms and give off a photon, and then you can
17:00
Speaker 1: capture those tiny, little dark flashes of light with foot
17:03
Speaker 1: a multiplier. Interesting, very scintillating for sure, and tantalizing. I
17:09
Speaker 1: mean basically, you have like a bathtub under a mile
17:12
Speaker 1: underground in the dark, with a camera attached to it,
17:14
Speaker 1: and you're waiting for little flashes of light, which could
17:17
Speaker 1: mean ironically dark matter exactly. You could be shedding light
17:21
Speaker 1: on dark matter. All right, Well that's what it was
17:23
Speaker 1: built for. But recently they announced that they saw something
17:26
Speaker 1: else and maybe even more interesting than dark matter. So
17:30
Speaker 1: let's get into that. But first let's take a quick break.
17:45
Speaker 1: All right. I know we're talking about this Zenon experiment
17:48
Speaker 1: that was built to detect dark matter. So it's a
17:51
Speaker 1: giant tub of zenon. It's sitting there, chilling, waiting for
17:55
Speaker 1: dark matter. But then they saw something that maybe it
17:58
Speaker 1: is not dark matter. Yes, So first of all, they've
18:01
Speaker 1: been looking for dark matter for a while and not
18:03
Speaker 1: seeing it, and other folks have been looking for dark
18:05
Speaker 1: matter for a while and not seeing it, and people
18:08
Speaker 1: started to get worried, like, well, maybe it's not there,
18:10
Speaker 1: or maybe it's different from what we expected, because these
18:14
Speaker 1: experiments are really good at seeing dark matter if it
18:17
Speaker 1: has a certain amount of mass, something between like ten
18:20
Speaker 1: and you know, maybe two hundred giga electron volts, which
18:24
Speaker 1: is about the mass of a proton. If dark matter
18:27
Speaker 1: was much lighter than that, it might not have enough
18:29
Speaker 1: energy to bump into the xenon atoms and excite them.
18:33
Speaker 1: It might be there, it might be flying through your detector.
18:36
Speaker 1: It might be bumping into the xenon atoms but not
18:38
Speaker 1: giving them enough energy to give off that flash of light.
18:41
Speaker 1: So people were worried about that scenario. So they pivoted
18:43
Speaker 1: and they said, well, let's use the same detector but
18:46
Speaker 1: trying to figure out a way to use it to
18:48
Speaker 1: look for lighter mass dark matter. And the way they
18:51
Speaker 1: do that is instead of looking for the xenon nucleus
18:54
Speaker 1: the protons and neutrons, that heavy blob at the center
18:56
Speaker 1: of the atom, they said, let's look forward bumping into
18:59
Speaker 1: the electron, because the electron is really light, has very
19:02
Speaker 1: very little mass. So they developed a technology to look
19:05
Speaker 1: for electron recoils instead of nuclear recoils. So those are different.
19:09
Speaker 1: Those are different. They give different signatures, Like if you
19:12
Speaker 1: bump an electron off of the xenon, all of a sudden,
19:15
Speaker 1: you have a charged particle inside this pool of xenon,
19:18
Speaker 1: and they have an electric field which will pull that
19:21
Speaker 1: electron out of this tub of zenon and measure it.
19:24
Speaker 1: So they can tell that signature separately from the nuclear recoil.
19:28
Speaker 1: Like a single electron or a single ion you can
19:30
Speaker 1: detect that. You can detect that because it triggers a
19:33
Speaker 1: little shower. It makes more of itself and that lets
19:35
Speaker 1: you detect it. Actually, you know the nuclear recoil and
19:38
Speaker 1: an electron recoil will give you scintillation light plus some
19:42
Speaker 1: ionization from the electrons, and so it's a game of
19:44
Speaker 1: like you know the ratios, you can tell them apart.
19:47
Speaker 1: Is a bit technical, but they can tell an electron
19:49
Speaker 1: recoil apart from a nuclear recoil, like are you hitting
19:53
Speaker 1: the center of the atom or you bouncing off one
19:55
Speaker 1: of the electrons on the side of it. Yeah, but
19:58
Speaker 1: does that require the dark matter to be like a
20:01
Speaker 1: certain energy? Like what if dark matter is also pretty
20:04
Speaker 1: chill and just you know, doesn't feel like interacting with zeno.
20:07
Speaker 1: But it's there and it could interact, but it's just chill. Yeah, well,
20:11
Speaker 1: that's one of the issues that we already know that
20:13
Speaker 1: dark matter is chill. We talked about this on a
20:15
Speaker 1: podcast pretty recently. Dark matter, we know is cold, meaning
20:18
Speaker 1: that's not moving at relativistic speeds, and so it doesn't
20:22
Speaker 1: have a whole lot of energy, which is why it
20:23
Speaker 1: has to be kind of massive in order to deposit
20:26
Speaker 1: some energy. We know that it's not carrying a lot
20:28
Speaker 1: of kinetic energy other way. But but I guess, I mean, like,
20:32
Speaker 1: what if it's there, it's interacting with the zenon but
20:35
Speaker 1: not at a you know, high enough energy or something.
20:38
Speaker 1: You know, it's just like gently bumping into the zeni.
20:41
Speaker 1: It could be. But remember that the Earth is moving
20:43
Speaker 1: around the Sun, and so we expect to have some
20:46
Speaker 1: velocity relative to the dark matter. Unless the dark matter
20:49
Speaker 1: happens to also be swirling around the Sun at the
20:51
Speaker 1: same rate, there should be basically a dark matter wind
20:54
Speaker 1: at all times. It's not really possible to have no
20:57
Speaker 1: velocity relative to the dark matter not hurt those words
21:00
Speaker 1: before dark matter winds. Yeah. In fact, there's a whole
21:02
Speaker 1: another generation of dark matter detectors. They're going to try
21:05
Speaker 1: to look for directional dark matter, not just like is
21:08
Speaker 1: dark matter coming in at all? But is it coming
21:10
Speaker 1: in this direction or is it coming in that direction?
21:13
Speaker 1: Is coming up from above or below? To try to
21:16
Speaker 1: be a little bit more sensitive to it, like catching
21:18
Speaker 1: the ether. Yeah, and if you do see dark matter,
21:21
Speaker 1: you expect it to have a modulation by season, like
21:23
Speaker 1: it should be going this way in the spring and
21:25
Speaker 1: that way in the fall. You really are sort of
21:28
Speaker 1: moving through a cloud of dark matter. Well, but back
21:30
Speaker 1: to this experiment, So they gave up on trying to
21:34
Speaker 1: detect it with the nucleus of the xenon atoms, and
21:37
Speaker 1: so they switched to detect nague with the electrons of
21:40
Speaker 1: the zenon atoms, and then they found something unexpected. Yeah,
21:43
Speaker 1: and you know, give up is a bit strong. These
21:45
Speaker 1: experiments are big, and they have different teams, so they
21:47
Speaker 1: have sort of like a bifurcated strategy. They're still looking
21:50
Speaker 1: for the zenon nuclear recoils, but now they added this
21:53
Speaker 1: other way to look for a dark matter, to look
21:55
Speaker 1: for the electron recoils, And so they look for it,
21:57
Speaker 1: and they ran this thing for a couple of years,
22:00
Speaker 1: been analyzing the data. And you know, it's not like
22:02
Speaker 1: you can just see one electron recoil and be like, oh,
22:05
Speaker 1: I found dark matter, because there are other things that
22:08
Speaker 1: can also kick an electron. You know, like you're like
22:12
Speaker 1: a mile underground and you're surrounded by weird minerals and
22:14
Speaker 1: this lead and crypton and stuff down there, and sometimes
22:18
Speaker 1: one of those atoms will decay radioactively and it will
22:22
Speaker 1: get through your shielding and it will kick one of
22:24
Speaker 1: your electron. So what you have to do is a
22:26
Speaker 1: careful calculation of like how often do you expect that
22:29
Speaker 1: to happen? And so you know, like, well, we expect
22:31
Speaker 1: that to happen in this case two hundred and thirty
22:34
Speaker 1: two times on average when we run this experiment, and
22:38
Speaker 1: then you can compare that to what you see. Do
22:40
Speaker 1: you see more than that or not I see? And
22:42
Speaker 1: so that's what they did. They you know, I guess
22:45
Speaker 1: they had calibrated it. They measured you know, the stuff
22:48
Speaker 1: outside of the box and the tub, and then they
22:51
Speaker 1: compared to what they saw inside of the tub and
22:54
Speaker 1: that was different. Yeah, the way they calibrated is actually
22:56
Speaker 1: they shoot radiation, they bring radioactive sources near it to
23:00
Speaker 1: verify that they can see them, and then they move
23:01
Speaker 1: them away to verify the signal disappears. So they can
23:05
Speaker 1: use that to verify like how sensitive they are to
23:08
Speaker 1: these radioactive measurements, and then they use other ways to
23:11
Speaker 1: measure like how much lead in krypton is surrounding our experiment.
23:15
Speaker 1: So they do a lot of work to really calibrate,
23:17
Speaker 1: and that's the name of the game. And these experiments
23:19
Speaker 1: where you're looking for like very small number of signals
23:22
Speaker 1: is beating down the background, suppressing all these other things
23:25
Speaker 1: that can look like you're dark matter, and then also
23:28
Speaker 1: understanding them very very precisely, calibrating very very carefully, just
23:33
Speaker 1: like with Lego and all those other very sensitive experiments.
23:36
Speaker 1: It's all about making a very quiet experiment and understanding
23:39
Speaker 1: how quiet it is, kind of like eliminating all the
23:42
Speaker 1: noise or taken into account all of the noise exactly
23:45
Speaker 1: all right. So they got more hits than they expected
23:49
Speaker 1: of something. They saw more of these scintillations, these photon
23:53
Speaker 1: events than they expected by a good number, that's right.
23:56
Speaker 1: So they expected two hundred and thirty two, and they
24:00
Speaker 1: analyzed all their data and they've got two D eighty five,
24:03
Speaker 1: which is something like fifty more than they expected. And
24:07
Speaker 1: they think they understand that number two thirty two pretty well,
24:10
Speaker 1: Like they're pretty confident in that number. So it's pretty
24:14
Speaker 1: unlikely for you know, lad in crypton to explain all
24:18
Speaker 1: these scintillations, like it could just be random chance. I mean,
24:21
Speaker 1: everything is quantum mechanical, and there are fluctuations, and they've
24:25
Speaker 1: done the calculations, but the probability of this just being
24:27
Speaker 1: like a fluctuation is like two and ten thousand. But
24:32
Speaker 1: you know, it still seems pretty amazing to me that
24:34
Speaker 1: it's a pretty small number. I mean, you know, twot
24:37
Speaker 1: two data points on a massive experiment with significance about
24:42
Speaker 1: the universe doesn't seem like a lot like I would
24:44
Speaker 1: expect thousands or millions of data points, kind of like
24:47
Speaker 1: you have in the article Collider. Yeah, it's a whole
24:49
Speaker 1: different kind of world, though. Mean, they are doing their
24:52
Speaker 1: best to make this really quiet because they expect a
24:55
Speaker 1: very rare signal, you know, And so if you're hunting
24:58
Speaker 1: for unicorn in the forests of Siberia, you scan a
25:02
Speaker 1: huge forest and you try to make your filter really
25:05
Speaker 1: really picky. So you find the unicorns. They're not just
25:07
Speaker 1: like drowning in ordinary horses when random horns in their
25:11
Speaker 1: foreheads exactly. But you're right, yeah, these data points are
25:16
Speaker 1: pretty rare. I mean, they ran for a couple of years,
25:18
Speaker 1: which means they get like one piece of data every
25:21
Speaker 1: day or two. That's crazy. The other side of this experiment,
25:24
Speaker 1: the nuclear recoil one, is even quieter because those events
25:28
Speaker 1: are even harder to mimic. And I remember times when
25:30
Speaker 1: they like they ran for two years and they saw
25:33
Speaker 1: two events and they expected one, and they were like, oh, interesting,
25:37
Speaker 1: what is the second event? Seriously, you know, and they
25:41
Speaker 1: get to know they did, like this is this event
25:43
Speaker 1: and that event. They have names and relationships with these events.
25:45
Speaker 1: Where were you when we found the second place? Exactly? Exactly?
25:49
Speaker 1: So this is actually kind of a big number for
25:51
Speaker 1: a dark matter experiment. They used to dealing with events
25:53
Speaker 1: like less than ten, but because they went over to
25:56
Speaker 1: the electron side of things, they have larger background, so
25:59
Speaker 1: they see more events. Okay, So I guess the idea
26:02
Speaker 1: is they were looking for dark matter and raining for
26:06
Speaker 1: dark matter to interact with the zene on and give
26:08
Speaker 1: up these events and they saw more than they expected
26:12
Speaker 1: even with dark matter, or more than they expected from
26:15
Speaker 1: like a baseline no dark matter scenario. They saw more
26:18
Speaker 1: than they expected from the no dark matter scenario, right.
26:22
Speaker 1: But the signal they see is kind of weird. It's
26:24
Speaker 1: not the signal you would expect to see from dark matter.
26:27
Speaker 1: It piques at a very very low electron energy, like
26:31
Speaker 1: just above where they're able to measure. That's where all
26:34
Speaker 1: these events are piling up. Oh, I see, So that's
26:37
Speaker 1: the mystery. That's the weird thing. It's they don't think
26:39
Speaker 1: this is dark matter that they're seeing. This doesn't look
26:42
Speaker 1: like dark matter. So they built this device to look
26:45
Speaker 1: for dark matter. It's very quiet, it's very beautiful, and
26:48
Speaker 1: they analyze the data and they see something in there
26:50
Speaker 1: which they can't explain using normal standard model physics and
26:54
Speaker 1: radioactive decays. But it also can't be described by dark matter.
26:58
Speaker 1: But how do you know it's not dark matter because
27:00
Speaker 1: we don't know what dark matter is. The signal that
27:02
Speaker 1: they see in the Zeni experiment can't be explained by
27:06
Speaker 1: dark matter. Whimps that they were looking for. To give
27:08
Speaker 1: electrons a kick in the way that they see would
27:11
Speaker 1: require a really fast moving particle, and we think dark
27:15
Speaker 1: matter is cold. I think it's slow moving. All right,
27:17
Speaker 1: So you're saying that they feel pretty sure that it's
27:19
Speaker 1: not dark matter, that it just doesn't look like the
27:22
Speaker 1: dark batter signal that they expect. I mean, they don't
27:25
Speaker 1: have a whole lot of handles on this data. You know.
27:27
Speaker 1: What they can do is look at the energy of
27:29
Speaker 1: the electrons that are kicked off, and they have a
27:32
Speaker 1: prediction for what that looks like if it's dark matter,
27:35
Speaker 1: and they have a prediction for what that looks like
27:36
Speaker 1: if there's no dark matter. And it doesn't agree with
27:39
Speaker 1: either of those scenarios, Like the energy distribution they see
27:43
Speaker 1: can't be explained by a dark matter party. Has to
27:46
Speaker 1: be like a third scenario, something else, that's right, it
27:48
Speaker 1: has to be something else. And so they came up
27:51
Speaker 1: with a few crazy ideas which, if they're real, could
27:54
Speaker 1: explain the signal and would like totally blow up physics.
27:58
Speaker 1: What they're like, it's unicorn, essentially, they went for physics unicorn.
28:04
Speaker 1: All right, let's get into what it could be. What
28:07
Speaker 1: kind of new and unexpected or groundbreaking types of physics
28:12
Speaker 1: could explain these results. But first let's take another quick break.
28:27
Speaker 1: All right, Daniel, So the Zenon experiment did not find
28:32
Speaker 1: dark matter as they built it, but they it found
28:34
Speaker 1: something else. It found electron signatures at an energy level
28:39
Speaker 1: that doesn't match with the predictions of dark matter. So
28:42
Speaker 1: it could be something else, that's right, And so they
28:45
Speaker 1: played around. They said, well, what is this, like, you know,
28:48
Speaker 1: what could this be? Could it be something else? Are
28:51
Speaker 1: there any other ideas out there, anything we weren't looking
28:54
Speaker 1: for but might be able to explain this weird signature
28:57
Speaker 1: that we do see. And they suggest in their paper
29:00
Speaker 1: a few possible explanations. They have several ideas for what
29:03
Speaker 1: this could be. They do. They have several ideas which
29:06
Speaker 1: range from like totally crazy to super boring. I see,
29:12
Speaker 1: from like pink unicorns to like, you know, nor walls
29:16
Speaker 1: that's just somehow migrated to the forest. Now it's like
29:18
Speaker 1: pink unicorns, to actually, maybe we didn't tighten the knobs
29:22
Speaker 1: well enough. Really. Uh well, let's start with the most
29:27
Speaker 1: boring one. The most boring is that it's not just
29:30
Speaker 1: Zenon in the tank, like they try to make it
29:33
Speaker 1: pure Zenon. They really work hard. There's a lot of
29:36
Speaker 1: really smart people doing this experiment. But if if instead
29:40
Speaker 1: of being pure zenon, it has just like a few
29:43
Speaker 1: atoms of tritium. Treatium is an isotope of hydrogen, and
29:47
Speaker 1: it's unstable. If you have like three atoms of tritium
29:51
Speaker 1: per kilogram of zenon, then it can decay to helium three,
29:55
Speaker 1: giving off an electron which looks exactly like this signature. Oh,
29:59
Speaker 1: I see, And they not only could it be a contamination,
30:03
Speaker 1: but they can pinpoint what kind of contamination it could be. Yes,
30:06
Speaker 1: And it's very hard to measure the amount of tritium
30:09
Speaker 1: in zenon. It's very hard to get it pure, and
30:11
Speaker 1: it's very hard to isolate the tritium, and so they're
30:14
Speaker 1: working on that. They're using all sorts of clever techniques
30:16
Speaker 1: to try to isolate the treatium and measure its separately, etcetera, etcetera.
30:20
Speaker 1: But this all could just be a bunch of puffery
30:23
Speaker 1: around a little bit of contamination in their zenon, Okay,
30:26
Speaker 1: because that's is that common to have tritium accidentally in
30:29
Speaker 1: your xenon. I mean, I don't have any first hand experience.
30:33
Speaker 1: I don't have any xenon in my house that I've purchased,
30:36
Speaker 1: But yeah, I mean xenon is naturally occurring and it's
30:39
Speaker 1: filtered out of the air, and in the process of
30:42
Speaker 1: gathering xenon sometimes impurities come in and so it's pretty
30:46
Speaker 1: hard to get like really really pure xenon. So it's
30:50
Speaker 1: something they were aware of, obviously, something they were worried about,
30:52
Speaker 1: and it is something that they can use to explain
30:55
Speaker 1: this signature without invoking crazy new pink unicorn particles. So
31:00
Speaker 1: they're working on nicely. But wouldn't that over time decrease,
31:03
Speaker 1: like as all the tritium decays, that would go down eventually.
31:07
Speaker 1: I suppose it would, but you know, this would be
31:09
Speaker 1: enough tritium in there to provide this signal. I mean,
31:13
Speaker 1: the tredium does have a pretty long half life, all right.
31:16
Speaker 1: So that's the most boring, sorry, at least exciting, most
31:19
Speaker 1: boring explanation for this result. And so what's the next
31:23
Speaker 1: most exciting. The next most exciting is that maybe they
31:26
Speaker 1: saw a weird kind of neutrino. Like we know the
31:29
Speaker 1: new trinos are out there. We've ruled out new trinos
31:32
Speaker 1: as dark matter because we know dark matter, if it's
31:35
Speaker 1: a particle, has to be pretty heavy. It's men move
31:38
Speaker 1: pretty slow. We know that because the way it's shaped
31:41
Speaker 1: the whole structure of the universe. So we know the
31:43
Speaker 1: neutrinos are out there, but there's not enough of them
31:45
Speaker 1: to explain the dark matter and they have too much energy.
31:49
Speaker 1: But people thought, you know, this huge device that we've
31:52
Speaker 1: built is also a good way to see neutrinos. Like
31:55
Speaker 1: if the neutrino flies through here and bounces into one
31:58
Speaker 1: of these electrons, then we see that. That's how they
32:01
Speaker 1: find the trinos in the first place, right, like a
32:02
Speaker 1: big tub of something chill, Yeah, exactly, big tub of
32:05
Speaker 1: something chill is a good way to find shy particle,
32:07
Speaker 1: especially you put it underground so you don't get bombarded
32:11
Speaker 1: by muans and all sorts of other stuff from cosmic rays.
32:14
Speaker 1: And so it's very similar technology to all the neutrino experiments,
32:18
Speaker 1: like we talked about the Doune experiment, which is, you know,
32:20
Speaker 1: fundamentally very similar to this experiment. Equally cool acronym, equally
32:24
Speaker 1: cool acronym. But to make this signature this sort of
32:27
Speaker 1: like weird spike in their electron spectrum, they need a
32:30
Speaker 1: particular kind of neutrino that we've never seen, which is
32:33
Speaker 1: a neutrino with a little magnetic field, like a non
32:37
Speaker 1: neutral neutrino. Yeah, neutrinos don't have electric charge, and we
32:42
Speaker 1: think that the reason that particles have a magnetic field
32:44
Speaker 1: is because they have both electric charge and this weird
32:47
Speaker 1: quantum spin. So it's not that they're actually spinning with
32:50
Speaker 1: there's some like weird particle analogy to spinning with charge.
32:55
Speaker 1: It gives you a little magnetic field. And we talked
32:57
Speaker 1: last week on the podcast about how a muan has
33:00
Speaker 1: a little magnetic dipole in north and the south and
33:03
Speaker 1: you can measure really precisely to learn secrets of the universe. Well, neutrinos,
33:07
Speaker 1: we don't think they have them, but if there was
33:10
Speaker 1: a kind of neutrino which did have a magnetic field,
33:14
Speaker 1: it would give you this kind of signature a new neutrina,
33:18
Speaker 1: a new kind of neutrino. Yeah, a neutrino that has
33:20
Speaker 1: a little magnetic field. I see. And is that even
33:23
Speaker 1: allowable in the sort of laws of physics or would
33:26
Speaker 1: this totally be new and break that down. This would
33:29
Speaker 1: be totally new, It would be crazy. You would have
33:31
Speaker 1: to really rework the whole standard model to allow for
33:34
Speaker 1: a neutrino that had any sort of like electromagnetic interactions,
33:38
Speaker 1: it would break a lot of stuff. But that's exciting, right,
33:40
Speaker 1: That's like, Hey, that's what we're doing this for. We're
33:42
Speaker 1: doing this to break our understanding so we can rebuild it. Right,
33:45
Speaker 1: That's that's what experimentalists are hoping to do, is to
33:48
Speaker 1: find something new and crazy. You're like, break it, break
33:51
Speaker 1: it exactly, but you know it's got to be real.
33:54
Speaker 1: And when you think about this got a new idea,
33:57
Speaker 1: you have to think like, well, if that existed, would
33:59
Speaker 1: we see it somewhere else? Is there another way we
34:01
Speaker 1: could have or should have spotted this? You know, are
34:04
Speaker 1: you just trying to explain the fact that you didn't
34:07
Speaker 1: really get pure zenon and make it sound dramatic. If
34:11
Speaker 1: these new kinds of neutrinos existed, they would interact with
34:14
Speaker 1: the zenon in a way that could maybe explain this
34:17
Speaker 1: weird data. Yes, okay, so that that sounds pretty i
34:20
Speaker 1: don't know, interesting in groundbreaking. But you're saying that there's
34:23
Speaker 1: a third possibility, which is even crazier. That's right. And
34:26
Speaker 1: so there's another idea, which is maybe they didn't see
34:29
Speaker 1: dark matter, maybe they didn't see neutrinos. Maybe what they
34:32
Speaker 1: saw where this weird particle called axions. We talked about
34:37
Speaker 1: axons a couple of episodes ago. Right, they're detergent particles, right,
34:40
Speaker 1: they clean up the other and Adams right there you go,
34:46
Speaker 1: they do all the dirty work of the universe. Yeah,
34:49
Speaker 1: They're a crazy particle invented to solve a problem in
34:52
Speaker 1: theoretical physics. You know why two things seemed to balance
34:56
Speaker 1: and we don't know why, and they invented this axion
34:58
Speaker 1: to give those things balance. And then as a bonus,
35:01
Speaker 1: people realized, hey, wait a second, maybe axons could be
35:04
Speaker 1: the dark matter. And we talked about it on the
35:06
Speaker 1: podcast a few weeks ago. And axions, if they exist,
35:09
Speaker 1: there's sort of like a photon, but they have a
35:11
Speaker 1: little bit of mass, but they're really really not very heavy.
35:13
Speaker 1: They're like a tiny little bit of mass like one
35:17
Speaker 1: one thousands of an electron bolt, which is very small
35:20
Speaker 1: given that like an electron is like half a million
35:23
Speaker 1: electron bolts. So these things, if they exist, would be like,
35:26
Speaker 1: you know, a billion times less mass than the electron, right,
35:30
Speaker 1: but you still sort of think of them as a
35:32
Speaker 1: heavy photon like photon with mass. That's right, And if
35:36
Speaker 1: axons are out there, then in order to be the
35:39
Speaker 1: dark matter, they need to not be moving very fast. Right,
35:42
Speaker 1: dark matter is cold and axons are very very low mass,
35:45
Speaker 1: and so this experiment couldn't see dark matter axios. But
35:50
Speaker 1: they said, all right, well we can't see dark matter axions.
35:53
Speaker 1: What if there's a new weird kind of axion, like
35:56
Speaker 1: one that's made in the sun and shot out with
35:59
Speaker 1: a lot of energy, so like a hot axion. Wow,
36:02
Speaker 1: it sounds like a reach. It's a bit of a reach. Yeah,
36:06
Speaker 1: it's a bit of reach. Like, let's let's put on
36:09
Speaker 1: all of our idea hats everyone, because we're gonna lose
36:12
Speaker 1: funding if we don't come up with some cool idea. Yeah,
36:15
Speaker 1: I thought you'd be impressed. It's sort of like you know,
36:17
Speaker 1: physics engineering. They're like, all right, what if we take
36:19
Speaker 1: a piece of this idea and we staple it to
36:22
Speaker 1: that idea and then we hang the whole thing on
36:24
Speaker 1: this third idea and it's sort of you know, we
36:26
Speaker 1: need to do. Is that why you think of engineering? Yeah?
36:30
Speaker 1: If you of engineering, like um, that's seen from a
36:33
Speaker 1: Pollar thirteen where they're like, what if he's duct tape
36:36
Speaker 1: to glue this tube over here. Exactly? Is that not?
36:39
Speaker 1: Is that not the high water mark for engineering? I mean,
36:43
Speaker 1: I'll let that pass. But then so you're saying, this
36:45
Speaker 1: is like a creative physics here, creative you know problems, Yes, yes, exactly,
36:50
Speaker 1: they're coming up. They're like, what can we do to
36:52
Speaker 1: explain this weird signal in an exciting way? Because who
36:55
Speaker 1: wants to write a boring paper about treatium. We want
36:58
Speaker 1: to write a paper saying, maybe we discover this crazy
37:00
Speaker 1: new thing that nobody ever thought could exist, but we
37:03
Speaker 1: might have broken open the universe, meaning because because if
37:06
Speaker 1: you do find this axon, this new kind of potential
37:09
Speaker 1: hypothetical particle. So it's like a hypothesis and a hypothesis, right,
37:13
Speaker 1: So I do you do find it? That would break
37:15
Speaker 1: the loss of physics? Well, it would be hard to
37:17
Speaker 1: explain because nobody knows why axons would be produced in
37:21
Speaker 1: the sun. And if they were produced in the sun
37:24
Speaker 1: in order to have enough speed to be seen by
37:27
Speaker 1: the Xenon experiment, then it would be cooled down the Sun.
37:31
Speaker 1: I could be pumping out a lot of energy, and
37:33
Speaker 1: we would expect stars in the sky to fade out
37:37
Speaker 1: much faster than we see So the solar axon is
37:40
Speaker 1: sort of already disfavored by lots of things in physics.
37:44
Speaker 1: It's sort of like contradicted by astrophysical measurements already. So
37:49
Speaker 1: if it does exist, it would be Yeah, if it
37:52
Speaker 1: does exist, it means we need to re understand how
37:54
Speaker 1: stars work, which is hey, that's exciting, and we need
37:57
Speaker 1: to understand like why stars are making this axon and
38:00
Speaker 1: this actually exists in this way, so that it would
38:02
Speaker 1: be a pretty big discovery. If solar axons were real.
38:05
Speaker 1: It would make us rethink a lot of stice. You
38:08
Speaker 1: have to rethink not just the standard model, but also
38:10
Speaker 1: like how stars work. Yeah, and we've gotten pretty good
38:13
Speaker 1: at understanding how stars work. You know, we have a
38:15
Speaker 1: good model for how they burn and how they die
38:18
Speaker 1: and the various kinds of stars that are out there,
38:20
Speaker 1: and so this would throw a wrench in like a
38:22
Speaker 1: pretty well established field. Right. So that's pretty exciting to
38:25
Speaker 1: be at a time when you know, an experiment like
38:28
Speaker 1: this that's high profile, find something unexpected, and it could
38:31
Speaker 1: be some pretty amazing things. Yeah, it could be. But
38:34
Speaker 1: you know, my personal opinion is that this is a
38:36
Speaker 1: big reach. You know, they see something weird in their data.
38:39
Speaker 1: It's cool, but you know, we see weird stuff in
38:41
Speaker 1: our data all the time, and usually it's because we
38:44
Speaker 1: didn't really understand the backgrounds. We didn't really understand the
38:47
Speaker 1: performance of our instrument. There was something weird going on,
38:50
Speaker 1: it was miscalibrated or some other source of these events
38:54
Speaker 1: that we didn't anticipate. And so you've got to be
38:57
Speaker 1: really skeptical. And that's why we have a really high
38:59
Speaker 1: threshold for believing that something there is new, Like, first
39:03
Speaker 1: of all, you have to see it in another experiment.
39:04
Speaker 1: An independent experiment would have to see the same thing,
39:07
Speaker 1: hopefully using slightly different technologies or you know, being differently
39:12
Speaker 1: sensitive to sources of bias. And the other thing that
39:15
Speaker 1: makes me wonder about this is if you have a
39:17
Speaker 1: chance to google it and to look at the data,
39:19
Speaker 1: you see that it all sort of piles up right
39:21
Speaker 1: on the edge of where they can see. You know,
39:23
Speaker 1: they can see electrons down to a certain energy, and
39:26
Speaker 1: then below that they just can't detect them, and all
39:29
Speaker 1: these things pile up right on the edge of where
39:31
Speaker 1: they're able to see, which always makes me suspicious, like
39:34
Speaker 1: do you really know what's going on at the very
39:36
Speaker 1: extreme ends of your detector. So it just makes me
39:39
Speaker 1: wonder if really, in the end, this this is an
39:41
Speaker 1: issue of understanding your detector response, I see, because I
39:44
Speaker 1: guess there's a secret option D, which is that it's
39:47
Speaker 1: just nothing. Yeah, that's just nothing, which is just like
39:50
Speaker 1: they just didn't calibrate it well, or you know, it's
39:53
Speaker 1: different than they were expecting because what they were expecting
39:56
Speaker 1: was wrong. Yeah. And I don't mean that they didn't
39:58
Speaker 1: do their jobs well or that they're not smart. This
40:00
Speaker 1: is super duper hard. They're doing something nobody else has
40:03
Speaker 1: ever done before. They're not just like ordering something from
40:06
Speaker 1: Amazon and turning it on right. They're pushing the which
40:10
Speaker 1: is basically engineering. It sounds like you said, you think
40:13
Speaker 1: that no engineering would be ordering six different weird things
40:18
Speaker 1: from Amazon and making them do something else That would
40:20
Speaker 1: be awesome engineering. But now these folks are pushing the
40:24
Speaker 1: boundaries of what can be done. They've won the race
40:27
Speaker 1: to get like the one Ton experiment up and running
40:30
Speaker 1: and working and with this new clever technique. And so
40:34
Speaker 1: I'm not criticizing them at all, But often when you're
40:36
Speaker 1: on the bleeding edge, you don't understand the data that
40:39
Speaker 1: comes in at first and it takes a wild to
40:41
Speaker 1: figure it out and to really damp it down. So
40:44
Speaker 1: that's where they are, and they don't know if this
40:46
Speaker 1: signature means, hey, the universe is telling you a deep
40:49
Speaker 1: secret that it's been waiting to reveal for fourteen billion years,
40:52
Speaker 1: or you know, you got to twist that novel a
40:54
Speaker 1: little harder because the experiment is not quite tightened up,
40:58
Speaker 1: and you're gotta chill that zeno in a little bit more. Yeah,
41:00
Speaker 1: it could be, but fortunately we do have more experiments coming.
41:04
Speaker 1: There's an experiment in the US that's coming up. It's
41:06
Speaker 1: called l Z and it's got basically the same strategy,
41:10
Speaker 1: a big tub of liquid zinn. And there's one in
41:13
Speaker 1: China called Panda X that's underground. That's huge. And so
41:17
Speaker 1: if this is real, they should also see it and
41:20
Speaker 1: we'll hear more from them soon. Right, Is it a
41:22
Speaker 1: requirement that they need to use some of the letters
41:24
Speaker 1: from the end of the alphabet, like Z X Why, well,
41:29
Speaker 1: you know it's xenon and so they've got to have
41:31
Speaker 1: an X in there somewhere, right, because x is are awesome.
41:36
Speaker 1: They marked the spot out here exactly. They're exciting, all right, Well,
41:39
Speaker 1: it sounds like stay tuned is the answer to this question.
41:43
Speaker 1: But it's got physicists excited, and it could mean that
41:47
Speaker 1: we need to rethink our signs that we have about
41:50
Speaker 1: the universe, you know, part of either the standard model
41:53
Speaker 1: or how stars work, or what kinds of netrinas there
41:57
Speaker 1: could be. So that's pretty exciting. Or it could be
42:00
Speaker 1: just that we need more data. Yeah, I hope it's
42:02
Speaker 1: something new. I hope that it's a it breaks physics
42:06
Speaker 1: and teaches us something about the universe. I'm pretty skeptical
42:09
Speaker 1: frankly then it's anything real. So but stay tuned and
42:12
Speaker 1: keep an open mind and an open heart, because that's
42:15
Speaker 1: why we do this stuff. We're asking the universe questions
42:18
Speaker 1: and we have to listen to what it tells us.
42:20
Speaker 1: All right, Well, we hope that answered the question, and
42:23
Speaker 1: we hope it provide it's some interesting things. Who think
42:25
Speaker 1: about for those of you who had not heard of
42:27
Speaker 1: this experiment, so stay tuned for more exciting us. That's right,
42:30
Speaker 1: because this dark tub liquid underground might be shedding light
42:34
Speaker 1: on dark matter. There might be a unicorn bathing in it.
42:39
Speaker 1: That is a very strange mental image, A big unicorn
42:44
Speaker 1: with an ex painting on its chest. I don't think
42:46
Speaker 1: that's ethical treatment of unicorns. To put them in a
42:48
Speaker 1: dark bathtub of mile underground, that's what they like, Daniel,
42:51
Speaker 1: Maybe we have to rethink our understanding of unicorns. I
42:56
Speaker 1: think the Society for the Ethical Protection of Unicorns is
42:59
Speaker 1: going to be what's the acronym for that society? UM,
43:06
Speaker 1: I'll pass that one on to my creative partner. All right, Well,
43:09
Speaker 1: we hope you enjoyed that. Thanks for joining us, see
43:11
Speaker 1: you next time. Thanks for listening, and remember that Daniel
43:22
Speaker 1: and Jorge explained. The Universe is a production of I
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Speaker 1: Heart Radio. For more podcast For my heart Radio, visit
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Speaker 1: listen to your favorite shows. Ye