June 30, 2020 • 48 mins
Why do scientists think there might be a wispy mysterious particle? And why did they give it such a silly name?
Learn more about your ad-choices at https://www.iheartpodcastnetwork.com
See omnystudio.com/listener for privacy information.
Mark as Played
Transcript
Episode Transcript
Available transcripts are automatically generated. Complete accuracy is not guaranteed.
Speaker 1 (00:08):
Hey, Daniel, if you ever discovered a particle, what would
you name it? Oh? I feel a little bit put
on the spot and no pressure. I mean, you wouldn't
just name it the white sun or the white cuno, did, DANIELO. Well,
you know, over the course of these podcasts, I've come
to get a feeling of, I don't know, judgment from
you by the quality of particle names. So I guess
(00:30):
I feel some responsibility to like do it right and
meet your high standards. Well, I'm glad I'm doing my
bid to make physics better. You know. I just hope
you don't give it a silly name, you know, like
a random name, like a squiggly on or something. You know,
those quiglyons. That would be a silly name. Well, I
promised to do my best. I won't like name it
after a random laundry detergent or something. All right, if
(00:52):
you do that, this podcast is over. Hi am Orhammad,
cartoonist and the creator of PhD comics. Hi. I'm Daniel.
(01:14):
I'm a particle physicist who has never discovered a particle,
at least one that nobody else has discovered. That's right.
I found particles this morning when I had breakfast and
I planned to find some more for lunch. But they're
all your everyday running the mill quirks and electron Yeah,
I find particles all the time in my belly button.
That's probably not a picture we want to paint this
(01:35):
really in the episode. That's probably what dark matter is. Jorge.
It's just your belly button. Oh yeah, my billy win
is full of dark matter and dark energy and physicists
also can't explain it. But welcome to our podcast, Daniel
and Jorge Explain the Universe, a production of I Heart
Radio in which we try to tackle the biggest questions
in the universe. What is dark matter, what is everything
(01:56):
made out of? What is that weird thing in Jorge's
belly button? And we try to do it in a
way that educates you and entertains you along the way.
And we like to talk about not just the science
and what we know about the universe and what we
don't know, but we also kind of like to talk
sometimes about the process of science, like how are things
discovered or what are scientists thinking about or what are
(02:17):
they looking for. That's right, because the forefront of science,
the edge of human curiosity, it belongs to everybody, and
we want you to know what are scientists thinking about,
what are they wondering about, what do they not know?
And what are they doing to figure it out? How
do we go from clueless too, slightly clued in, slightly
less clueless, diminishing cluelessness. That'll be the title of my autobiography. Yeah,
(02:39):
we would like to kind of stand at the precipice
of ignorance. I'd like to call it like, we're right
at the edge of what scientists know and don't know
and what they're discovering right now at the moment. Do
you think we are in danger of falling into that
precipice or we're pushing it back. I think it's possible
to go a little bit too deep into the rabid
hole here of what we don't know in physics. Just
(03:00):
following up on your metaphor there, does that make the
rabbit is ignorance or rabbits are ignorant? Well, I don't
want to insult any rabbits. We're definitely pro rabbit on
this podcast. Were we are we like rabbits here? But
you know, one question is that you know there are
all these particles out there in the universe and there's
a whole bunch of particles we've discovered in the universe,
(03:22):
and and so the kind of the question is like,
how do people find new particles? How do you physicists
discover them? Yeah, there's sort of two big ways to
do it. One is to look at the list of
particles we have now and say it doesn't seem complete.
We need another one. And this is the case when
we talked about the top cork, for example, we had
a nice little pattern of particles with a missing square
(03:43):
in it. There was one particle that didn't have a
partner and everything else was paired off, so we thought
there must be one there. And sometimes, more abstractly, we
say there's just a larger pattern that would make sense
if we added one more particle. That's how the Higgs
boson was discovered, for example. So you're saying particle physics,
it's it's kind of like pokemon collecting or baseball card collecting. Yeah,
(04:04):
except we can't trade. You know, if the aliens come,
maybe we could trade our discoveries for their for theirs. Right,
Oh my goodness, your nerve brain just exploded. I'll give
you a Higgs boson for the dark matter. Please? Do
you have dark matter? We want dark matter? Boy? That
would be uh, that does sound kind of like fun.
You know, you can get together the neighborhood and you
(04:25):
exchange what do you know about the universe. I'm looking
forward at that party. But there's a whole other way
to discover particles, which is just to sort of stumble
across them, to like find them in nature and see
them and go what's that and then figure out how
does it fit into the larger puzzle, where does this go?
How do we connected? And we haven't done too much
of that recently. Mostly we've been predicting particles and then
(04:48):
find I see. So how would you stumble upon a
particle like you're running the collider or any kind of
collider and then suddenly you see something you weren't expecting. Yeah, precisely.
This is how mu ones were discovered. For example, they
had big blocks of photographic materials up on the tops
of mountains and they saw these streaks of particles going
through them, and the particles weren't consistent with electrons or
(05:08):
anything else, and so they said, well, this must be
some new particle we haven't seen before. And colliders are
actually the best place to discover a new, unexpected particle
because you smash the protons together and you get this
little blob of energy which can turn into anything. Anything
the universe is capable of making, and so you could
just pop out some crazy new particle you've never seen
(05:30):
before without you knowing that it exists. You don't have
to know it's there in order to find it. That's
the amazing thing about exploring the universe with colliders. You'd
be like, who ordered that exactly where that? That's exactly
literally what they said when they heard about the mule,
and they said, what, we don't need that. That doesn't
make any sense. Go take that somewhere else. Well, we've
(05:51):
had several episodes where we talk about the discovery and
the search for different particles. We had one about the
top cork and the electron and all these other particles.
And so today we'll tell the story of another particle,
one that was proposed almost forty years ago and that
we are still looking for. That's right, this is a
particle which may or may not exist, and if it
(06:13):
does exist, it may simultaneously solve two of the biggest
problems in particle physics and weirdly, it's a particle almost
nobody outside the field has even heard of. Wow, well,
I guess we we don't know if it exists, and
so if it doesn't exist, we have to erase this
podcast episode. Daniel or no, we get paid Either way,
(06:34):
it doesn't really matter. Okay, forget about that. Well apparently
has the one of the citiest names in the history
of particles. Yes, I'm looking forward to hearing your reaction
to how this particle was named. It ends up with
a really pretty cool name. But the reason for that
name is really pretty ludicrous and whimsical. Oh man, I
(06:54):
am not looking forward to that. But anyway, So today
on the podcast, we'll be asking the question, what is
the most important particle you've never heard of? It's just
like a trendy band that everyone should listen to but
nobody knows about. Yeah, this is the particle your teenager
knows about, but you are clueless about it. It's super
(07:16):
hot on TikTok You're like, what what is TikTok? That's
precisely you don't even know the name of the social
media app on which this particle is cool. That's how
uncool you are. No, but it is. It is a
really cool name. I like. I like the sound of
the name of this particle. It's this particle is called
the axion. That does sound pretty cool. It does sound
(07:38):
pretty cool. What doesn't invoke in your mind or him
like a robot or you know, like um like access
maybe Unfortunately, the word for armpits in Spanish is kind
of close to it, So it is making me think
a little bit of art pits. But we won't go
there is an unfortunate name. It makes me think of
(08:00):
sort of like double edged axes being thrown in space
along three different axes, you know, like X and y
ax and your y ax and your zo throwing an
X and X around. I don't know, I don't know,
but it is a cool name. It's fun to say.
It's got that same sound in their idea. I think
as long as it sounds like a transformer, it sounds
(08:21):
I think cool. In physics, you know, synchrotron, graviton megatron
is not a particle, though the awesome there you go,
that will be the name of a particle. Some of
you may have heard about the new interesting axon result
from the Zenon experiment. Now today we'll be talking about
the axon more generally, but we're going to dig into
(08:41):
the zenon solar axon question in a dedicated episode coming
very soon. But as usual, I was curious, what did
people know about the axon? Is this something people actually
have heard of or is this something that only the
cool kids on physics TikTok know about? And so is
Daniel went out there into the files of the Internet
to ask people what they know about the axion particle.
(09:04):
So thank you to everybody who volunteered to answer random
Internet questions and sending in your responses. If you'd like
to participate in random person on the street internet questions,
then please write to us at questions at Daniel and
Jorge dot com. Before you hear these answers, think about
it for a second and someone as you if you
knew what the axion particle was, what would you say.
(09:29):
Here's what people had to say. I think this is
a way to classify particles. They like they can be axion,
some boat songs and it has to do with them,
for example, having mass or not. I don't know. I
guess action access would perhaps be some sort of particle
(09:50):
that other particles turn around. I have no idea but
since it sounds like the word axel, I'm going to
guess it has something to do with joining other particles together.
I have no idea. I don't know. I think that's
to do with what doll matter is might of I
believe there are two options, are actions or whimps. Honestly,
(10:12):
I have no idea. Because it has the word ion
in it, maybe it's some kind of ion. It's got
no idea. I never heard about something called axiom. Yeah,
of course that's an elementary particle of an action figure
the Caveman scientists in your book discussing what the most
fundamental particle of a stone ax would be. I assume
(10:36):
it's not a standard particle. Maybe it's more like strange matter.
All right, not a lot of positive recognition there. I
like the one that said it's it's an action figure,
or it's related to an action figure, the fundamental element
of an action figure. That makes a lot of sense. Well,
if it does exist and it is part of nature,
(10:57):
it could be part of all action figures. It could be.
And the other great idea was the that maybe it's
related to axles, so maybe like joins particles together at
this some really creative responses here, I'm impressed, or maybe
they were thinking like Axel Rose and like oh, I'm
a gone some Roses fan, in which case the Axon's
career has to also be in the dusk. Yeah, they
(11:17):
better get on that physics TikTok right away. Some silly dances.
But it did seem like none of these folks had
heard of this particle or really had any clue about
its incredibly important role in particle physics. Man, well, I
would count myself among those numbers. I had no idea
what this and have no idea of what this particle
is before he sent me the outline for today's episode.
(11:38):
But let's get into it, Daniel, what is the axion?
It sounds kind of important but maybe not yet discovered. Yeah,
the axion particle is totally theoretical, so we do not
know if it's part of our universe at all. It
may just be an idea in people's minds. And remember
there's been a lot more ideas than actual particles. And
sometimes these ideas are beautiful, they make perfect sense, and
(12:01):
when the physicist has them, they go, Wow, everything is
connected and this is the way the universe works. But
then you go and you ask the universe like is
it real? And Uver says, nice idea, but no, isn't
that kind of strange? I feel like that's almost like
trying to discover new animals by thinking of them before
you actually find. It's like, oh, what if there's an
(12:21):
animal with a duck bill, but then at a dinosaur
nag and then butterfly wings, and then you go out
looking for them. Wouldn't that be kind of not productive? Yeah? Well,
but to stretch the you know, mixed metaphor of our
rabbit holes here, it's more like that you see evidence
for this animal. It's like what's eating all the deer?
And you know, I see all these strange footprints, and
maybe that would be explained if there was this new
(12:43):
predator out there I've never seen before. And so you're
trying to like tie up loose ends and complete the
picture by suggesting an explanation. And that's exactly what the
axion and a lot of other theoretically motivated particles do,
is they sort of trying to tie together what we
see in a small all are more compact explanation. It's
just been a pretty horrible picture of this animal. Daniel
(13:04):
because around eating deer. Oh my goodness, it's like a
wolf man. You're trying to go for a cool animal wolf,
the duck bill and butterfly wings. It does sound pretty cool.
That does sound pretty cool. I want to see that
animal if it exists, and you can name it. We
already use that name for something else. That would be
so confusing. But what if you find animal first, right, Like,
(13:27):
what if you find animal and call it the axion
before you discover this particle. I think we've already used
up the name though. That's sort of like, you know
how the Space Force television show on Netflix has trademarked
the term Space Force before the actual US Space Force
got around doing it. Oh that's a problem. That's a problem, yeah, exactly. Anyway,
(13:47):
back to particle physics, the axion, if it exists, is
a lot like a photon, but it doesn't have zero mass.
It has a super tiny, little whispy mask really massive photon. Yeah,
but it's not very massive. Like the mass if it
has some is like two hundred billion of the mass
of the electron, which is already one of the lightest particles.
(14:12):
So it's like a light light particle. It's like light light. Exactly.
It's very light light light, but not quite light, not
quite light. It's not coke zero. It's like coke light, Yeah, exactly,
it's that coke with a tiny little bit of real
sugar in it, right, Um, And why did somebody come
up with this, Well, they came up with it to
sort of answer the biggest problem in physics that nobody
(14:33):
ever heard of, which is, we're looking at the way
that interactions happen in physics, and we noticed something weird,
something that we cannot explain. And so it's sort of
thought up to explain this other mystery the same way
you know, you might hypothesize wolves if you see your
dear missing. This is sort of like hypothesizing the axon
to explain this other problem, which is called the strong
(14:54):
CP problem. Interesting, and now is its official title, the
biggest problem with notity has ever heard of? Like, do
you guys talk about it that way? Yeah, it's sort
of a famous problem that nobody really has any answer
to except the axio. And so that's why people think
the axon might really be real. And then we'll talk
later in the program about how it could also simultaneously
(15:15):
solve another huge problem, which makes the axon sort of
a sexy particle right now. But it was originally dreamt
up to solve this other problem called the strong CP problem.
So what what's the strong CP problem? So this problem
has to do with basically, why does the strong force
not break some symmetries and particle physics, we have all
these symmetries like charge symmetry and parity symmetry and time symmetry.
(15:39):
These symmetries tell us whether something works the same when
you flip it the other way. Like, if we say
something could happen to an electron, we ask, well, can
the same thing happen to a positron, which is the
opposite charge version of it. Because we like symmetries in
particle physics, we like the smallest set of rules, so
we don't want a different set of rules for electron
(16:00):
ones and for positrons for example. So it's kind of like,
you know, like if two negative electrons propel each other,
you can ask, like to positive electrons propel each other too,
and if they do, then that means it's like symmetric.
That's right, it's symmetric in charge. If you flip the
charge and you get the same thing, and then it's
symmetric in charge, and so we call that C for
charge symmetry, and we ask that question about everything, and
(16:22):
electromagnetism is charge symmetric. Everything that happens in electromagnetism would
happen the same way if you flipped all of the charges,
not just one, but all of the charges, okay. And
then the second one is called P for parity violation,
and that says, would the same thing happen if you
did it in the mirror. So, if you like set
up some particle experiment or particle decays to two other ones,
(16:46):
or two particles collide into each other or whatever, and
then you put that experiment in front of a mirror,
the thing that happens in the mirror is not exactly
the same as the thing that's happening in real life.
It's flipped in one dimension. Yeah, a mirror will flip
like the Z axis, for example, the axis perpendicular to
the mirror, but not the other two. So, for example,
if you hold up your left hand in front of
(17:08):
a mirror, then it looks like your right hand doesn't
look like your left hand, and so your hand has parody.
It's not parody symmetric, right, because it doesn't look the
same in the mirror. Doesn't look the same, but like
a like a ball does sort of look like a
perfectly round ball with no drawings or features on it
does is parody symmetric because it looks the same in
the mirror exactly. So for a long time, this is
(17:30):
this thought that all of particle physics was charged symmetric
and parody symmetric because it just sort of made sense, right,
and this is like to do that. They say, the
universe is beautiful and natural, and so it should follow
this rule, Like it'd be weird if the electron looked
like my right hand in front of the mirror, or
if you had electrons for hands, that would also be weird,
but for different reasons. And for a long time, everybody
(17:52):
assumed that everything followed all these rules. And then in
the fifties people realized, oh, nobody had ever actually checked this.
For the weak force, we had a whole episode we
dug into how the weak force actually violates parity. Interesting, Yeah,
if you have a reaction in the mirror, it looks
different than the reaction you're having like in your actual laboratory.
And when we're talking about these These are particles, right,
(18:14):
so they don't have features like hands, but they'll do
things like they'll turn a certain way in a magnetic field,
or they'll they'll react a certain way when they hit
something else. Right. Yeah, the experiment that discovers the violation
of parody did just that. It like takes a bunch
of nuclei, aligns them in a magnetic field, and then
watches the direction that they emit electrons. Is it like
in the same direction as the magnetic field or backwards?
(18:37):
And that's a fascinating experiment that if you're interested in
you should dig into that whole podcast episode. But for
a whild people thought, okay, parody is violated by the
weak force. What about the combination of charge and parody?
So put it in the mirror and flip the charge,
so that says, will an electron look the same if
you put it in the mirror and turn it into
(18:58):
a positron? And then we discovered that that the weak
force actually violates this also, so we call this c P.
If an interaction or a particle physics thing that happens
violates CP, it means that it doesn't look the same
when you flip the charge and put it in the mirror.
So and so the weak force violates parody, and it
(19:20):
also violates charge and parody. That's right now violates parody
big time. It's like a really big violation. And that
was a Nobel prize. And then people thought, well, it
must then preserve CP. It must be that parody is violated,
but the combination of these two things is still preserved.
And then they discovered that they violates CP, and that
was another Nobel prize. So that's the weak force. A
(19:43):
weak force violates CP, and that was sort of surprising.
But then people realized, well why not, I mean, why
shouldn't these things violate CP. They looked at the way
that we write down these interactions and the way we
understand these theories, and we say, well, it's actually totally
natural for them to violate CP. So like the theorist
went from that's impossible, that's absurd, to actually make a
(20:03):
perfect sense. All right, Well, it sounds like there's a
lot going on with the weak force here. It violates
all kinds of symmetries, and so let's talk about some
of the other forces and how that could maybe lead
people to come up with a brand new particle called
the axion. But first let's take a quick break. All right, Diane,
(20:32):
we're we're talking about a potentially existing particle with a
cool name called the axion, and you're telling me that
it's definitely related to this idea of the CP problem,
which is like a problem in theoretical physics about the
symmetry of particles and whether or not they act the
same way in all kinds of situations. And so we
(20:53):
talked about how the weak force doesn't follows parody or
charged parody symmetry, and so and and that's now become
the normal. Before we gave them people a norval price.
We're figuring that out. But now it's like, okay, that's
the way, that's right. We realize that it's actually not
outrageous for the weak force to violate CP. And then
we looked at the other forces. We said, you know,
(21:14):
the same thing that allows the weak force to violate CP,
why doesn't it also allow the strong force to do it? Like,
the strong force could also violate CP, No big deal,
as the sort of same freedom inside it. It also
interacts with corks, which is what the weak force does
when it violates parody, and so people thought, oh, well,
the strong force, maybe that also violates CP. But but
(21:37):
it doesn't. But it doesn't. And we've made really really
precise measurements of this, like crazy precise measurements, and so
the strong force observes CP sort of for no good reasons. Interesting, so, like,
if you try the strong force, it seems to be symmetric.
It follows the rules. It's like, it follows the rules.
(21:59):
It's the good citizen of physics. Yeah, it's like if
you were watching people drive down the highway and every
single one of them was driving exactly at the speed limit,
no higher, no lower, to like one billions of a
mile per hour, you'd be like, that's weird. That would
be suspicious precisely, and you'd wonder, like, oh, maybe there's
a speed trap out there or something like that. Ord
(22:19):
their engines are fixed or something. You look for a reason, right,
or they're all using cruise control. Yeah, precisely, and it's
automated by the government or something. And so that's what
makes us wonder. We see this parameter in the strong
force that would very naturally allow for the strong force
to violate CP, but it doesn't. It's like this angle
that would allow it is set to exactly zero, and
(22:41):
that seems weird. It seems like it needs an explanation.
And that's the strong CP problem is why doesn't the
strong force violate CP. It's called I just got it, Daniel.
It's called the strong CP problem because it applies to
the strong force, that's right, not because it's a strong problem. Well,
you know something, problems are called like the you know,
(23:01):
like in uh, I don't know, the hard problem of consciousness, etcetera. Yeah,
or in computer science and they're like, you know, strong
there is the strong and thropic principle and the weakend
thropic principle. Yeah there you go. Yeah, I'm not crazy
that those exist. But that doesn't mean you're not crazy, Okay, Right,
it's not an exclusionary all right. So, um, it's the
strong city people, But it's not actually a problem. It's
(23:22):
more like it's like a strong why does it follow
the rules? Yeah? Question, it's not really a problem, right,
Like it's not causing any problem. It's just something that's
it's hard to understand why it doesn't break the rules. Yeah,
it's not gonna like fundamentally rip the universe. Apart or something.
It's not gonna bring the apocalypse upon us or anything.
We don't have to call Bruce Willis. It's not that
kind of problem. It's the why does this work that
(23:45):
way when it doesn't have to? You know, it's it's strange.
And anytime you see something unexplained and weird, a pattern
you don't understand in physics, you've got to ask why,
and you've got to think, is there a simpler explanation?
Is there something that's making this happen? So some people,
I guess I had to think of this question, right
because before you thought that was totally normal. It was
(24:06):
following the rules, but now it's weird. Suddenly became weird
that it was following the rule. Yeah, exactly. Once we
realized the rules could be broken, we thought, hey, how
come everybody's gonna breaking the rules? Right? Why is the
strong force over there being so nice but you can
drive as fast as you want in the highway? Why
is everyone driving under the speed limit? Yeah? The weak
forces like driving the wrong way, it's driving any speed,
(24:26):
it's driving the mill of the night, it's like going
off road. And the strong forces like driving Miss Daisy
right down in the right in the correct lane. Oh man,
all right, so um, so that's weird. And so people
started asking this question in the seventies. Yeah, it was
in the seventies that people came up with maybe the
first answer to this question. People started asking this question
(24:47):
basically after CP violation was discovered, which is, you know,
just a few years earlier. And then people came up
with his explanation, and it's from Roberto Pechy and Helen Quinn.
There's the nineteen seventy seven and of course very three
is let's think up a new quantum field that fills
the whole universe. Like that's the go to course. Let's
(25:09):
just add more things to the zoo, I know. And
it feels complicated, right, it feels counterintuitive, like we're trying
to simplify things, and to simplify things, we have to
add a new complicated bit. Like yeah, that's all right,
It's that seems counterintuitive. But it's like say you're trying
to describe how an engine worked and you were missing
the pistons. You'd be like, well, this doesn't really make sense.
I'm gonna add one more piece. Oh look, it all
(25:31):
clicks together now it makes sense and so sometimes you
have to add one missing piece in order to make
the whole machine work, or your understanding of the machine
work at least. Right. Well, I imagine it's weird because
you know, really, you guys, I sort of just looking
at some equations on a page, right, But it's like, oh,
if I, if I could add just one number here
would work. But really you're like you're adding a whole
(25:53):
new field to the entire universe just by putting that number.
Some of us experimentalists do more than just look at
pencils and paper, you know, we actually go out and
smash particles and try to make this stuff. Oh sorry, yeah,
you also look at computer screens. That's right. That is
fundamentally different. Okay. My wife used always tease me that
my research was just quote on the computer and therefore
(26:14):
wasn't real research. I see, you don't make chemicals, or
you don't have to wear a lab code. I'm not
wearing a lab coade, So how can it be science? Right, exam,
you can, but it's just strictly cosmetic, that's right. And
so they thought of this field, and they said, well,
what if there's this new field that fills up all
of space, and it's connected to the same field that
(26:35):
controls the strong force, this field of quantum chromodynamics, the
field of the gluons, these particles that mediate the strong force,
and what if it talks to those, It like interacts
with those, and it basically keeps it in line. And
so there's this new field created in a very early
universe with everything else, and it sort of pushes the
strong force in the direction of having no CP violation
(26:58):
I see, but not the other forces like it only
somehow affects the strong force. That's right, only affects a
strong force. And it was created just with everything else.
And then in the first sort of a few moments
of the universe, it pushed the strong force towards having
a zero value for this angle that controls the CP violation.
(27:18):
So not instantaneously like there may be in like a
bill of second there in the very early universe where
the strong force could violate CP. But then it was
sort of like pushed in line by this other field. Really,
but I guess my question is why do you need
this special field? Couldn't did just say that the strong
force that's the way it is, like it was born
with this angle. Why do you need to bring in
(27:40):
like a field that accent it and then somehow disappears. Yeah,
you could go with the non answer right to say,
you know, physics doesn't have explanations, so stop asking questions.
You know, like the numbers just are what they are.
It's not really satisfying. You wonder like why is it
this and not that? Especially when the numbers are a
simple value. I mean, if the number is like point
four to one seven, you wonder what it is. But
(28:01):
when the number is like zero or one's just it
hints at something else happening. It hints at something else
controlling it. Just like seeing those people drive down the
street at all the same speed. You wonder what's doing it?
But I guess you know, like how does it adding
a whole new field help Because we had a whole
new field. Then you have to ask why does that
field exist? Yeah, exactly, just like you have to ask
why do the pistons exist in the engine. But if
(28:23):
you think them up, it does simplify all the parts
working together in the way that you observe. And so
they thought of this field and they try to make
it as simple as possible and very naturally connected to
the strong force, and in in that connection between the
strong force and this new field forced the strong force
sort of automatically to have zero CP violation. It's sort
(28:45):
of like transforming one question into another. You're saying, you know,
why is this angle? Zero gets transformed into why does
this field exist? Sure? Okay, and that's I guess that's
a more comfortable question for you, guys, because because we
like fields, man, because then without it you get out
of a job. Well, also, the field is something we
(29:06):
could discover, right, and so if this field exists, we
can go out and find it, and then you can ask, Okay,
why does that field exists? Why do we need all
these fields? Is it part of some larger strategy. I
don't know, but it is something that we can test
and fine, right, as opposed to like just some weird
property of the strong force. Yeah, you can measure this
property the strong force all day long and say zero.
(29:27):
That doesn't help you understand why it happens. If it,
if it can transform into it's forced to happen because
this field exists, and we can prove that field exists,
then we can start to think about the larger puzzle
and like, well, why this field and does this mean
other fields have to exist? And what does this tell
us about the pattern of all the fields, which is
sort of the larger mission of particle physics is to
understand how all the fields fit together into one. Right.
(29:48):
And I guess it's not totally crazy because that's how
they discovered the Higgs boson, right, Like you thought of
a field to patch something in your theories, and then
you found the particle that belonged to that field. So
it's all sort of been buttoned up. Yeah, exactly. The
question there was like, why does the photon have no
masks and these other particles do have masks? Can you
explain that? And some people were like, hey, just accept
(30:10):
it and move on, man, but Higgs was like, no,
I'm going to create a new field that explains it.
And he was right. And so now we can of
course ask a questions like why is there a Higgs
field dot dot We get to get onto the next question.
And so just like that, this new field creates a
new particle, and that new particle is something we could discover,
all right. And so there's a fun story and by
(30:33):
fun I mean crazy story about how it was name,
how they name axion came about, so tells the story.
So it's it's sort of funny for two reasons. First
of all, Petchi and Quinn, who thought of this field,
forgot to name the particle. Like they came up with
this field, and of course, naturally the field exists, that
it's possible for the field to get like an excited
bundle of energy, which we call a particle. But they
(30:55):
didn't name the particle. And so another physicist came along,
Frank will Check, who's famous and he won a Nobel
Prize for understanding how quirks interact with each other with
a strong force. He decided to name it. He's like, well,
let's think about this field and how we might see it.
And of course he thought about the particle, and then
he had to give it a name. No how he
(31:15):
got to name it, but the particle already had parents.
How can you just go in and like name somebody
else's kids. Say you met a family and they didn't
give their kids a name, you would probably come up
with a nickname for it, right, You wouldn't want to
say that kid's name. I would tell the parents to
give him a name. I would ask the parents, what
do they call what do they say when they want
the kid to come over? Well, then you are more
(31:35):
modest than Frank will Check, which is true for almost
all of humanity anyway. Oh my goodness. So wait they
but did they name? Did Peshi and Helen Quinn name
the field at least? Or did they just say like
a field? Yeah, a field? They just gave it a
mathematical symbol, right. They didn't give a name to the
particle that comes from it. And so you know, if
Frank Wilcheck had been less modest, he would have called
(31:56):
it the Petchy Quinn particle or something, or the field
or what will Check called the field? Yeah, well now
it's called the Axion field. Oh man, he totally took
it over. He totally took it over. And on top
of that, he gave it a totally ridiculous name, like
Axon is a cool name. But he got the idea
when he was grocery shop. Oh no, what happened. He
was in the aisle for laundry detergent and he saw
(32:19):
this laundry detergent called Axion detergent booster, and he thought Axion,
that's kind of a cool name. Oh no, well, he
was what was he thinking, like this particle that I'm
earth surfing and stealing from this other other physicists would
clean everything up pretty well. So, hey, laundry detergent makes
perfect sense. It's a physics booster, so we need a
(32:40):
detergent booster. Yeah, so somebody in some marketing department created
the name for this laundry detergent, which ended up naming
a theoretical particle. But didn't they copyrighted? Can you do that?
That's a great question. Can you name a particle after
like U copyrighting your name in a particle like the
Nintendo Switch particle or like the Netflix particle. Can't do that?
(33:04):
You know, that's a question for our legal department, for
the physics lawyers. You stumped me on that one. Through
the physics lawyers, of whom I am not one. And
you know, there was competition. There were other famous Nobel
Prize winning physicists like Stephen Weinberg. He wanted to call
it the Higgs lit because he thought, oh, this is
only reminds me a little bit of the Higgs boson,
So he wanted to call it things you're gonna say.
(33:24):
You wanted to name it clox or Kleenex or the
tidy no particle um no and accalon sort of stuck.
And you know, these things are not fair, and they're
not always done the right way. Like we talked about
how quirks are named quarks because the famous physicists came
up with the name, even though a young physicist came
(33:45):
up with the name aces before that and it was
sort of buried in obscurity. But these things are not
always done correctly. They're not always given to the people
who to That's right, Yeah, it's not always fair. It's
just sort of like what people end up calling something.
All right, Well let's get into why this action is
super duper cool and why we think it could be real.
(34:08):
But first let's take a quick break. All right, Daniel,
we're talking about the Axon and it got its name
from a laundry detergent, which is I guess not too
(34:28):
surprising in physics, because you know, I'm not impressed by
the general imagination and naming things. But it is a
cool sounding name at least, you know, it satisfies your
transformer principle. Well well, why then did you still Megatron's name,
you know, Optimus Prime? Yeah, maybe they had better lawyers. Right,
the detergent companies lawyers are not as good as the
transformers has bro. Yeah, that is a little bit scarier. Alright.
(34:53):
So you're telling me that this particle is cool because
it would answer the question of why the strong force
the is not violate some of these symmetry conditions in
the universe and that. But it could also be cool
because it explained another big problem. Yeah, there's another big
problem in particle physics, which is where is all the stuff? Right,
(35:14):
we know that most of the stuff in the universe
is not made of quarks and electrons or any other
kind of familiar matter. It's a man of this new
thing that we call dark matter, even though we don't
really know what it is. And just like with the
other sort of physics mysteries, we see evidence for it
and how galaxy spin and how light bends through space,
(35:35):
but we don't know what it is and what it's
made out of. So it's one of the biggest pressing
questions in particle physics, or I think in modern science,
what is the matter of the unit? What is dark matter? Right?
And so it could be axios, it could be laundry detergent,
it could be exactly the dark matter could be scrubbing
the universe. It seems ironic that dark matter would be
(35:57):
something that's supposed to get the stains out reisely. Well,
it satisfies a lot of the requirements you need for
a dark matter doesn't interact with normal matter, so we
wouldn't have seen it. That's what makes it dark. It
has some mass to it, although it's very very light.
So if it were dark matter, you would need like
a ridiculous number of these things. You need like two
(36:18):
hundred billion just to make the mass of one electron,
and we need enough to make five times as much
mass as everything in the universe. And so like, if
axions are the dark matter and they are real, then
we are swimming and swimming and jillions of axions all
the time, meaning that um, if these particles exist and
(36:41):
they explained this strong force problem, they could also be there,
but we wouldn't see them. Like they don't interact with
the electromagnetism. That's right, they don't interact with electromagnetism, and
they do connect to the strong force, but only in
this way that they make the strong force not violate CP.
The field also has some other super duper heavy particles
(37:02):
in it that do interact with a strong force, but
they're so heavy that they potentially don't exist, and so
we don't have to worry about them. And so effectively,
axions are totally inert except for the fact that they
have a small mass. And so if they have this mass,
then they contribute to gravity. And that's what dark matter is.
It's something mysterious out there that's adding gravity to the universe,
(37:24):
and so it could be the act All right, well,
would that be sort of a coincidence that we have
this particle and it just so happens to fill in
the blankford dark matter? It would be amazing, Like who
wouldn't want to solve two big problems in physics at once, Right,
you think of this particle to solve one problem, and boom,
it turns out to solve the other problem at the
same time. You can collect two Nobel Prizes in one trip.
(37:47):
I mean that sounds pretty. You get to like, do
you get too in the same ceremony? I wonder I
think you have to come back the next year. I'm
not sure, but that's attractive but also makes you a
little suspicious, Like we thought this particle up to explain
the strong ep problem, and then we have this other problem.
We're gonna try to sort of squeeze this particle into
solving the dark matter problem. It actually sort of reflects
(38:08):
something else about the dark matter problem, which is that
we're getting a teensy bit desperate. Like we thought we
would have figured out dark matter by now. We had
better ideas for what dark matter could be, these weakly
interacting massive particles stuff like that, and none of that
has really panned out, and so now we're sort of
like dragging along the bottom of the barrel looking for
other ideas that might explain dark matter. And so that
(38:31):
sort of led to a resurgence and interest in the axons.
People think, wait a second, what about axons? Maybe those
could be the dark matter. Like so desperate, you're reaching
for the non brand laud exactly what you're saying, that's
exactly where we are. And it could also maybe solve
another big problem, right it could it could solve another
big problem. That was a really fascinating paper out there
(38:52):
last year that talked about those first few moments in
the universe when this field was created and it forced
the strong field to not violate CP and it turns
out when it did that, it had sort of two directions.
It could go sort of like imagine a marble in
an upside down hat, and it's rolling towards the bottom,
and that's how it forces the strong force to not
(39:13):
violate CP. But if instead of just rolling strength down,
what if it had like a little bit of a kick,
so it sort of went around in a circle and
then relaxed to the center, then it could have done
it clockwise or counterclockwise. Oh boy, it's like another symmetry.
It's another symmetry. And it turns out if it goes clockwise,
then the universe is filled with matter, and if it
goes counterclockwise, the universe is filled with anti matter. What
(39:38):
it's like flipping a coin. We could have been made
out of antimatter. Yes, And that's a big question in physics,
is like why is the universe made out of matter
and not antimatter? And we don't know. And it feels
like a coin was flipped and it could be that
this was the coin. It was a laundry detergent coin
that determined the entire universe. Yeah, and so the axon
(40:00):
could solve this other problem also, so it really could
be key to a lot of these big, big mysteries
in particle physics. And I guess you're because I imagine
you were saying that this is not the only idea,
like this is not the only field or particle that
people have dreamed of, but this one is somehow more
attractive because it's sort of makes more sense, well, because
(40:22):
the other ones have been sort of ruled out. You know,
you have your first idea, you go look for it,
the experiment says no, sorry. Then you go for your
second idea, you know, and you just keep looking through
ideas until you find one that the universe says yes to.
And so that's sort of led to a resurgence. And
you know, also theoretical physics, there are trends, there are fads.
People get excited about an idea and they work on
(40:43):
it furiously, and then they get bored with it. Somebody
else comes up with a new idea, and so the
idea sort of have cycles. You know, People get bored
of an idea, put it aside, and then twenty years later,
some new young woman says, hey, I have found a
new way to use this old idea, and then everybody
gets excited about it. Again, it's a human endeavor, all right.
So then the action is is trending is what you're saying,
(41:04):
Like it's it's having a popularity, surgeon popularity. And so
I guess the question is is it real? Like does
it actually exist? And can I find it in places
not my laundry the diurgent aisle at my grocery store. Well,
we don't know, but there are experiments out there to
look for it, sort of two different categories of experiments
that both use magnetic fields. The idea is that the
(41:27):
axion is still or like a photon and it doesn't
interact with photons and normally, but it turns out that
if you put the axion into a super duper strong
magnetic field, then sometimes it will turn into photons. Wait,
a magnetic magnetic field can cause particles to change. Yes,
the magnetic field will change the way the particles interact. Right,
(41:49):
it has energy in it, and if those particles can
feel photons in any sort of way, then they can
get enhanced and they can change the way they decay.
And so the axion and if it's in a chamber
that sort of resonates with it and it's that chamber
is filled with magnetic field, and this magnetic fields is
like a hundred and fifty thousand times the strength of
(42:10):
the Earth's magnetic field, then it could sometimes turn into
like little microwave photons. So they have this cavity up
in University of Washington where they have very cold and
they have a very powerful magnetic field, and they're just
listening for a little microwave blip, so that we can't
see them, but they might turn into things. We can
see them precisely into in need these weird conditions, in
(42:33):
very strange, very strong conditions, they might turn into photons. Really,
you can predict that with the equations. The equations say
should happen if you get the magnetic field at the
right frequency and you get it down to cold enough conditions,
and they've been running it for a while and they
haven't seen them, but they're sort of like tuning the
magnetic field, like are they over here? Are they over there?
(42:53):
And so far they haven't seen anything, but it's sort
of getting more and more powerful. The device pretty cool.
All So that's one way. What's the other way that
we might see them? The other way, sort of the opposite,
is to try to turn light into axions, Like instead
of having axon turn into photons, turn that around. Take
a beam of light and try to turn it into
axions by putting the light. Yeah, like make light disappear. Yes,
(43:17):
And so this experiment is called light shining through walls
because you basically have a wall and a really strong
magnetic field and then a beam of light and the
ideas maybe the light will turn into axions which can
then pass through the wall with no problem, which will
then turn back into light and you can sort of
like have your light, you know, passed through the wall
(43:38):
by phase through the wall, by becoming an axon as
it's going through the wall. I feel I feel like
you're getting to the point where you're like, we need
ideas or what's what's this is? This is a comic book?
What there was a superhero that can go through walls?
Oh that sounds like a great idea. Yeah, well it's
pretty cool because if we figured out then we could
actually build beams of light that go through walls. Right.
(43:59):
So also sort a cool experiment because you just need
like a light beam and a wall and then you
just look for light making it through the wall. Right,
So it's pretty dramatic, seething magical X rays. Yeah yeah,
turning light and X rays making them penetrate just like
X rays. And it's pretty fun, you know, to see
these experiments. These are clever ideas, These are wacky ideas,
(44:21):
and personally, I never expect these experiments to actually discover
the axion. What though, isn't this your field? This is
my field? Yes, but the accon has always seems sort of,
I don't know, out there to me, like too crazy.
An idea just feels like a little bit out there
in left field, like yeah, it's a little too sutsy.
(44:41):
Like I've read this interview with Helen Quinn, one of
the two people who came up with the original idea,
and even she's a little amused that this idea is
still lacks She's like, I don't know what all the
fuzzes about. Direct quote from her is Roberto and I
spent a few months cooking up this theory, and now
the experimentalist has spent forty years look for it. She's
laughing at you, Daniel, It's like she's she's amused by you.
(45:05):
The whole thing was a joke to begin with. What
you guys doing wasting your time, Like that's what. We
didn't give it a name. It was all a big
practical joke, and then we planted the detergent for Frank
whil Chick to find it using their time travel device, right,
their magical X ray life. But it's fun, and you know,
sometimes an idea can begin from a silly place, just exploring,
(45:28):
just fuxing around with the math, and then turn into
something real. I mean, if the axion is real and
it solves these big open questions in physics, then that
would have been a productive few months cooking up that
crazy theory and productive forty years because you know, like
the it's almost like the Higgs boson, right, do you
predicted it? And like forty years later they found it. Yeah,
it took almost fifty years to find the Higgs. So
(45:49):
sometimes you come up with a theory for a particle
that's really really hard to find. It's not always easy
to go out and just like look for this thing,
even if you know what it's supposed to do and
how it's supposed to look, creating those conditions to find
it is not always easy, especially if it's elusive. I mean,
if it's the dark matter. Then it's been hiding for
a long time, and and the stakes are pretty high, Like,
if you find it, it would explain to so many things,
(46:11):
including dark matter and antimatter and strong CP problem. Yeah,
it would really close off a lot of big open
questions in physics. So from that point of view, I
sort of hope it is real because they would be
a fascinating inside into the universe. And then, like as
always with physics, when we get to ask the next question,
like all right, well, why is there an axion? What
does that mean? Is there another axion? You know, the
(46:34):
whole spectrum of axion particles, And so the questions never
really end right whenever there are lawyers that the Axon Corporation,
they're like just waiting for you guys to discover it
to give them that marketing boost in popular culture, or
that's when they're going to see right there you go,
They're gonna they're waiting, like, we own this. You can't
(46:54):
you can't make X rays light special laser beams without us.
That's right, We demand you pack up all your axions
and boxes and send them to us immediately. Alright, Well,
I think as usual, this just points to the things
we don't know and how you know, science is actively
still trying to explain the universe. That's right, And then
a hundred years we could look back and think, what
was it like before physics knew about the axion particle
(47:18):
or the chlorox particle or whatever it is we're going
to discover in twenty years, but before we know it,
it's just an idea. It feels very different to be
on the ignorance side of a discovery than on the
knowledge side, because you never know what could turn out
to be true. That's right, because the universe is no
strangers to weirdness. All right, Well, we hope you enjoyed that.
And the next time you're going down the grocery store
(47:40):
laundry detergent, I'll look around. You might discover a new
particle that explains the universe. Keep your eyes open, or
at least discover a cool name for somebody else's good idea.
You go. Thanks for joining us. Let's see you next time. Yeah,
(48:03):
thanks for listening, and remember that. Daniel and Jorge Explain
the Universe is a production of I Heart Radio. For
more podcast for my heart Radio, visit the i Heart
Radio app, Apple podcasts or wherever you listen to your
favorite shows,
Hey, Daniel, if you ever discovered a particle, what would
you name it? Oh? I feel a little bit put
on the spot and no pressure. I mean, you wouldn't
just name it the white sun or the white cuno, did, DANIELO. Well,
you know, over the course of these podcasts, I've come
to get a feeling of, I don't know, judgment from
you by the quality of particle names. So I guess
(00:30):
I feel some responsibility to like do it right and
meet your high standards. Well, I'm glad I'm doing my
bid to make physics better. You know. I just hope
you don't give it a silly name, you know, like
a random name, like a squiggly on or something. You know,
those quiglyons. That would be a silly name. Well, I
promised to do my best. I won't like name it
after a random laundry detergent or something. All right, if
(00:52):
you do that, this podcast is over. Hi am Orhammad,
cartoonist and the creator of PhD comics. Hi. I'm Daniel.
(01:14):
I'm a particle physicist who has never discovered a particle,
at least one that nobody else has discovered. That's right.
I found particles this morning when I had breakfast and
I planned to find some more for lunch. But they're
all your everyday running the mill quirks and electron Yeah,
I find particles all the time in my belly button.
That's probably not a picture we want to paint this
(01:35):
really in the episode. That's probably what dark matter is. Jorge.
It's just your belly button. Oh yeah, my billy win
is full of dark matter and dark energy and physicists
also can't explain it. But welcome to our podcast, Daniel
and Jorge Explain the Universe, a production of I Heart
Radio in which we try to tackle the biggest questions
in the universe. What is dark matter, what is everything
(01:56):
made out of? What is that weird thing in Jorge's
belly button? And we try to do it in a
way that educates you and entertains you along the way.
And we like to talk about not just the science
and what we know about the universe and what we
don't know, but we also kind of like to talk
sometimes about the process of science, like how are things
discovered or what are scientists thinking about or what are
(02:17):
they looking for. That's right, because the forefront of science,
the edge of human curiosity, it belongs to everybody, and
we want you to know what are scientists thinking about,
what are they wondering about, what do they not know?
And what are they doing to figure it out? How
do we go from clueless too, slightly clued in, slightly
less clueless, diminishing cluelessness. That'll be the title of my autobiography. Yeah,
(02:39):
we would like to kind of stand at the precipice
of ignorance. I'd like to call it like, we're right
at the edge of what scientists know and don't know
and what they're discovering right now at the moment. Do
you think we are in danger of falling into that
precipice or we're pushing it back. I think it's possible
to go a little bit too deep into the rabid
hole here of what we don't know in physics. Just
(03:00):
following up on your metaphor there, does that make the
rabbit is ignorance or rabbits are ignorant? Well, I don't
want to insult any rabbits. We're definitely pro rabbit on
this podcast. Were we are we like rabbits here? But
you know, one question is that you know there are
all these particles out there in the universe and there's
a whole bunch of particles we've discovered in the universe,
(03:22):
and and so the kind of the question is like,
how do people find new particles? How do you physicists
discover them? Yeah, there's sort of two big ways to
do it. One is to look at the list of
particles we have now and say it doesn't seem complete.
We need another one. And this is the case when
we talked about the top cork, for example, we had
a nice little pattern of particles with a missing square
(03:43):
in it. There was one particle that didn't have a
partner and everything else was paired off, so we thought
there must be one there. And sometimes, more abstractly, we
say there's just a larger pattern that would make sense
if we added one more particle. That's how the Higgs
boson was discovered, for example. So you're saying particle physics,
it's it's kind of like pokemon collecting or baseball card collecting. Yeah,
(04:04):
except we can't trade. You know, if the aliens come,
maybe we could trade our discoveries for their for theirs. Right,
Oh my goodness, your nerve brain just exploded. I'll give
you a Higgs boson for the dark matter. Please? Do
you have dark matter? We want dark matter? Boy? That
would be uh, that does sound kind of like fun.
You know, you can get together the neighborhood and you
(04:25):
exchange what do you know about the universe. I'm looking
forward at that party. But there's a whole other way
to discover particles, which is just to sort of stumble
across them, to like find them in nature and see
them and go what's that and then figure out how
does it fit into the larger puzzle, where does this go?
How do we connected? And we haven't done too much
of that recently. Mostly we've been predicting particles and then
(04:48):
find I see. So how would you stumble upon a
particle like you're running the collider or any kind of
collider and then suddenly you see something you weren't expecting. Yeah, precisely.
This is how mu ones were discovered. For example, they
had big blocks of photographic materials up on the tops
of mountains and they saw these streaks of particles going
through them, and the particles weren't consistent with electrons or
(05:08):
anything else, and so they said, well, this must be
some new particle we haven't seen before. And colliders are
actually the best place to discover a new, unexpected particle
because you smash the protons together and you get this
little blob of energy which can turn into anything. Anything
the universe is capable of making, and so you could
just pop out some crazy new particle you've never seen
(05:30):
before without you knowing that it exists. You don't have
to know it's there in order to find it. That's
the amazing thing about exploring the universe with colliders. You'd
be like, who ordered that exactly where that? That's exactly
literally what they said when they heard about the mule,
and they said, what, we don't need that. That doesn't
make any sense. Go take that somewhere else. Well, we've
(05:51):
had several episodes where we talk about the discovery and
the search for different particles. We had one about the
top cork and the electron and all these other particles.
And so today we'll tell the story of another particle,
one that was proposed almost forty years ago and that
we are still looking for. That's right, this is a
particle which may or may not exist, and if it
(06:13):
does exist, it may simultaneously solve two of the biggest
problems in particle physics and weirdly, it's a particle almost
nobody outside the field has even heard of. Wow, well,
I guess we we don't know if it exists, and
so if it doesn't exist, we have to erase this
podcast episode. Daniel or no, we get paid Either way,
(06:34):
it doesn't really matter. Okay, forget about that. Well apparently
has the one of the citiest names in the history
of particles. Yes, I'm looking forward to hearing your reaction
to how this particle was named. It ends up with
a really pretty cool name. But the reason for that
name is really pretty ludicrous and whimsical. Oh man, I
(06:54):
am not looking forward to that. But anyway, So today
on the podcast, we'll be asking the question, what is
the most important particle you've never heard of? It's just
like a trendy band that everyone should listen to but
nobody knows about. Yeah, this is the particle your teenager
knows about, but you are clueless about it. It's super
(07:16):
hot on TikTok You're like, what what is TikTok? That's
precisely you don't even know the name of the social
media app on which this particle is cool. That's how
uncool you are. No, but it is. It is a
really cool name. I like. I like the sound of
the name of this particle. It's this particle is called
the axion. That does sound pretty cool. It does sound
(07:38):
pretty cool. What doesn't invoke in your mind or him
like a robot or you know, like um like access
maybe Unfortunately, the word for armpits in Spanish is kind
of close to it, So it is making me think
a little bit of art pits. But we won't go
there is an unfortunate name. It makes me think of
(08:00):
sort of like double edged axes being thrown in space
along three different axes, you know, like X and y
ax and your y ax and your zo throwing an
X and X around. I don't know, I don't know,
but it is a cool name. It's fun to say.
It's got that same sound in their idea. I think
as long as it sounds like a transformer, it sounds
(08:21):
I think cool. In physics, you know, synchrotron, graviton megatron
is not a particle, though the awesome there you go,
that will be the name of a particle. Some of
you may have heard about the new interesting axon result
from the Zenon experiment. Now today we'll be talking about
the axon more generally, but we're going to dig into
(08:41):
the zenon solar axon question in a dedicated episode coming
very soon. But as usual, I was curious, what did
people know about the axon? Is this something people actually
have heard of or is this something that only the
cool kids on physics TikTok know about? And so is
Daniel went out there into the files of the Internet
to ask people what they know about the axion particle.
(09:04):
So thank you to everybody who volunteered to answer random
Internet questions and sending in your responses. If you'd like
to participate in random person on the street internet questions,
then please write to us at questions at Daniel and
Jorge dot com. Before you hear these answers, think about
it for a second and someone as you if you
knew what the axion particle was, what would you say.
(09:29):
Here's what people had to say. I think this is
a way to classify particles. They like they can be axion,
some boat songs and it has to do with them,
for example, having mass or not. I don't know. I
guess action access would perhaps be some sort of particle
(09:50):
that other particles turn around. I have no idea but
since it sounds like the word axel, I'm going to
guess it has something to do with joining other particles together.
I have no idea. I don't know. I think that's
to do with what doll matter is might of I
believe there are two options, are actions or whimps. Honestly,
(10:12):
I have no idea. Because it has the word ion
in it, maybe it's some kind of ion. It's got
no idea. I never heard about something called axiom. Yeah,
of course that's an elementary particle of an action figure
the Caveman scientists in your book discussing what the most
fundamental particle of a stone ax would be. I assume
(10:36):
it's not a standard particle. Maybe it's more like strange matter.
All right, not a lot of positive recognition there. I
like the one that said it's it's an action figure,
or it's related to an action figure, the fundamental element
of an action figure. That makes a lot of sense. Well,
if it does exist and it is part of nature,
(10:57):
it could be part of all action figures. It could be.
And the other great idea was the that maybe it's
related to axles, so maybe like joins particles together at
this some really creative responses here, I'm impressed, or maybe
they were thinking like Axel Rose and like oh, I'm
a gone some Roses fan, in which case the Axon's
career has to also be in the dusk. Yeah, they
(11:17):
better get on that physics TikTok right away. Some silly dances.
But it did seem like none of these folks had
heard of this particle or really had any clue about
its incredibly important role in particle physics. Man, well, I
would count myself among those numbers. I had no idea
what this and have no idea of what this particle
is before he sent me the outline for today's episode.
(11:38):
But let's get into it, Daniel, what is the axion?
It sounds kind of important but maybe not yet discovered. Yeah,
the axion particle is totally theoretical, so we do not
know if it's part of our universe at all. It
may just be an idea in people's minds. And remember
there's been a lot more ideas than actual particles. And
sometimes these ideas are beautiful, they make perfect sense, and
(12:01):
when the physicist has them, they go, Wow, everything is
connected and this is the way the universe works. But
then you go and you ask the universe like is
it real? And Uver says, nice idea, but no, isn't
that kind of strange? I feel like that's almost like
trying to discover new animals by thinking of them before
you actually find. It's like, oh, what if there's an
(12:21):
animal with a duck bill, but then at a dinosaur
nag and then butterfly wings, and then you go out
looking for them. Wouldn't that be kind of not productive? Yeah? Well,
but to stretch the you know, mixed metaphor of our
rabbit holes here, it's more like that you see evidence
for this animal. It's like what's eating all the deer?
And you know, I see all these strange footprints, and
maybe that would be explained if there was this new
(12:43):
predator out there I've never seen before. And so you're
trying to like tie up loose ends and complete the
picture by suggesting an explanation. And that's exactly what the
axion and a lot of other theoretically motivated particles do,
is they sort of trying to tie together what we
see in a small all are more compact explanation. It's
just been a pretty horrible picture of this animal. Daniel
(13:04):
because around eating deer. Oh my goodness, it's like a
wolf man. You're trying to go for a cool animal wolf,
the duck bill and butterfly wings. It does sound pretty cool.
That does sound pretty cool. I want to see that
animal if it exists, and you can name it. We
already use that name for something else. That would be
so confusing. But what if you find animal first, right, Like,
(13:27):
what if you find animal and call it the axion
before you discover this particle. I think we've already used
up the name though. That's sort of like, you know
how the Space Force television show on Netflix has trademarked
the term Space Force before the actual US Space Force
got around doing it. Oh that's a problem. That's a problem, yeah, exactly. Anyway,
(13:47):
back to particle physics, the axion, if it exists, is
a lot like a photon, but it doesn't have zero mass.
It has a super tiny, little whispy mask really massive photon. Yeah,
but it's not very massive. Like the mass if it
has some is like two hundred billion of the mass
of the electron, which is already one of the lightest particles.
(14:12):
So it's like a light light particle. It's like light light. Exactly.
It's very light light light, but not quite light, not
quite light. It's not coke zero. It's like coke light, Yeah, exactly,
it's that coke with a tiny little bit of real
sugar in it, right, Um, And why did somebody come
up with this, Well, they came up with it to
sort of answer the biggest problem in physics that nobody
(14:33):
ever heard of, which is, we're looking at the way
that interactions happen in physics, and we noticed something weird,
something that we cannot explain. And so it's sort of
thought up to explain this other mystery the same way
you know, you might hypothesize wolves if you see your
dear missing. This is sort of like hypothesizing the axon
to explain this other problem, which is called the strong
(14:54):
CP problem. Interesting, and now is its official title, the
biggest problem with notity has ever heard of? Like, do
you guys talk about it that way? Yeah, it's sort
of a famous problem that nobody really has any answer
to except the axio. And so that's why people think
the axon might really be real. And then we'll talk
later in the program about how it could also simultaneously
(15:15):
solve another huge problem, which makes the axon sort of
a sexy particle right now. But it was originally dreamt
up to solve this other problem called the strong CP problem.
So what what's the strong CP problem? So this problem
has to do with basically, why does the strong force
not break some symmetries and particle physics, we have all
these symmetries like charge symmetry and parity symmetry and time symmetry.
(15:39):
These symmetries tell us whether something works the same when
you flip it the other way. Like, if we say
something could happen to an electron, we ask, well, can
the same thing happen to a positron, which is the
opposite charge version of it. Because we like symmetries in
particle physics, we like the smallest set of rules, so
we don't want a different set of rules for electron
(16:00):
ones and for positrons for example. So it's kind of like,
you know, like if two negative electrons propel each other,
you can ask, like to positive electrons propel each other too,
and if they do, then that means it's like symmetric.
That's right, it's symmetric in charge. If you flip the
charge and you get the same thing, and then it's
symmetric in charge, and so we call that C for
charge symmetry, and we ask that question about everything, and
(16:22):
electromagnetism is charge symmetric. Everything that happens in electromagnetism would
happen the same way if you flipped all of the charges,
not just one, but all of the charges, okay. And
then the second one is called P for parity violation,
and that says, would the same thing happen if you
did it in the mirror. So, if you like set
up some particle experiment or particle decays to two other ones,
(16:46):
or two particles collide into each other or whatever, and
then you put that experiment in front of a mirror,
the thing that happens in the mirror is not exactly
the same as the thing that's happening in real life.
It's flipped in one dimension. Yeah, a mirror will flip
like the Z axis, for example, the axis perpendicular to
the mirror, but not the other two. So, for example,
if you hold up your left hand in front of
(17:08):
a mirror, then it looks like your right hand doesn't
look like your left hand, and so your hand has parody.
It's not parody symmetric, right, because it doesn't look the
same in the mirror. Doesn't look the same, but like
a like a ball does sort of look like a
perfectly round ball with no drawings or features on it
does is parody symmetric because it looks the same in
the mirror exactly. So for a long time, this is
(17:30):
this thought that all of particle physics was charged symmetric
and parody symmetric because it just sort of made sense, right,
and this is like to do that. They say, the
universe is beautiful and natural, and so it should follow
this rule, Like it'd be weird if the electron looked
like my right hand in front of the mirror, or
if you had electrons for hands, that would also be weird,
but for different reasons. And for a long time, everybody
(17:52):
assumed that everything followed all these rules. And then in
the fifties people realized, oh, nobody had ever actually checked this.
For the weak force, we had a whole episode we
dug into how the weak force actually violates parity. Interesting, Yeah,
if you have a reaction in the mirror, it looks
different than the reaction you're having like in your actual laboratory.
And when we're talking about these These are particles, right,
(18:14):
so they don't have features like hands, but they'll do
things like they'll turn a certain way in a magnetic field,
or they'll they'll react a certain way when they hit
something else. Right. Yeah, the experiment that discovers the violation
of parody did just that. It like takes a bunch
of nuclei, aligns them in a magnetic field, and then
watches the direction that they emit electrons. Is it like
in the same direction as the magnetic field or backwards?
(18:37):
And that's a fascinating experiment that if you're interested in
you should dig into that whole podcast episode. But for
a whild people thought, okay, parody is violated by the
weak force. What about the combination of charge and parody?
So put it in the mirror and flip the charge,
so that says, will an electron look the same if
you put it in the mirror and turn it into
(18:58):
a positron? And then we discovered that that the weak
force actually violates this also, so we call this c P.
If an interaction or a particle physics thing that happens
violates CP, it means that it doesn't look the same
when you flip the charge and put it in the mirror.
So and so the weak force violates parody, and it
(19:20):
also violates charge and parody. That's right now violates parody
big time. It's like a really big violation. And that
was a Nobel prize. And then people thought, well, it
must then preserve CP. It must be that parody is violated,
but the combination of these two things is still preserved.
And then they discovered that they violates CP, and that
was another Nobel prize. So that's the weak force. A
(19:43):
weak force violates CP, and that was sort of surprising.
But then people realized, well why not, I mean, why
shouldn't these things violate CP. They looked at the way
that we write down these interactions and the way we
understand these theories, and we say, well, it's actually totally
natural for them to violate CP. So like the theorist
went from that's impossible, that's absurd, to actually make a
(20:03):
perfect sense. All right, Well, it sounds like there's a
lot going on with the weak force here. It violates
all kinds of symmetries, and so let's talk about some
of the other forces and how that could maybe lead
people to come up with a brand new particle called
the axion. But first let's take a quick break. All right, Diane,
(20:32):
we're we're talking about a potentially existing particle with a
cool name called the axion, and you're telling me that
it's definitely related to this idea of the CP problem,
which is like a problem in theoretical physics about the
symmetry of particles and whether or not they act the
same way in all kinds of situations. And so we
(20:53):
talked about how the weak force doesn't follows parody or
charged parody symmetry, and so and and that's now become
the normal. Before we gave them people a norval price.
We're figuring that out. But now it's like, okay, that's
the way, that's right. We realize that it's actually not
outrageous for the weak force to violate CP. And then
we looked at the other forces. We said, you know,
(21:14):
the same thing that allows the weak force to violate CP,
why doesn't it also allow the strong force to do it? Like,
the strong force could also violate CP, No big deal,
as the sort of same freedom inside it. It also
interacts with corks, which is what the weak force does
when it violates parody, and so people thought, oh, well,
the strong force, maybe that also violates CP. But but
(21:37):
it doesn't. But it doesn't. And we've made really really
precise measurements of this, like crazy precise measurements, and so
the strong force observes CP sort of for no good reasons. Interesting, so, like,
if you try the strong force, it seems to be symmetric.
It follows the rules. It's like, it follows the rules.
(21:59):
It's the good citizen of physics. Yeah, it's like if
you were watching people drive down the highway and every
single one of them was driving exactly at the speed limit,
no higher, no lower, to like one billions of a
mile per hour, you'd be like, that's weird. That would
be suspicious precisely, and you'd wonder, like, oh, maybe there's
a speed trap out there or something like that. Ord
(22:19):
their engines are fixed or something. You look for a reason, right,
or they're all using cruise control. Yeah, precisely, and it's
automated by the government or something. And so that's what
makes us wonder. We see this parameter in the strong
force that would very naturally allow for the strong force
to violate CP, but it doesn't. It's like this angle
that would allow it is set to exactly zero, and
(22:41):
that seems weird. It seems like it needs an explanation.
And that's the strong CP problem is why doesn't the
strong force violate CP. It's called I just got it, Daniel.
It's called the strong CP problem because it applies to
the strong force, that's right, not because it's a strong problem. Well,
you know something, problems are called like the you know,
(23:01):
like in uh, I don't know, the hard problem of consciousness, etcetera. Yeah,
or in computer science and they're like, you know, strong
there is the strong and thropic principle and the weakend
thropic principle. Yeah there you go. Yeah, I'm not crazy
that those exist. But that doesn't mean you're not crazy, Okay, Right,
it's not an exclusionary all right. So, um, it's the
strong city people, But it's not actually a problem. It's
(23:22):
more like it's like a strong why does it follow
the rules? Yeah? Question, it's not really a problem, right,
Like it's not causing any problem. It's just something that's
it's hard to understand why it doesn't break the rules. Yeah,
it's not gonna like fundamentally rip the universe. Apart or something.
It's not gonna bring the apocalypse upon us or anything.
We don't have to call Bruce Willis. It's not that
kind of problem. It's the why does this work that
(23:45):
way when it doesn't have to? You know, it's it's strange.
And anytime you see something unexplained and weird, a pattern
you don't understand in physics, you've got to ask why,
and you've got to think, is there a simpler explanation?
Is there something that's making this happen? So some people,
I guess I had to think of this question, right
because before you thought that was totally normal. It was
(24:06):
following the rules, but now it's weird. Suddenly became weird
that it was following the rule. Yeah, exactly. Once we
realized the rules could be broken, we thought, hey, how
come everybody's gonna breaking the rules? Right? Why is the
strong force over there being so nice but you can
drive as fast as you want in the highway? Why
is everyone driving under the speed limit? Yeah? The weak
forces like driving the wrong way, it's driving any speed,
(24:26):
it's driving the mill of the night, it's like going
off road. And the strong forces like driving Miss Daisy
right down in the right in the correct lane. Oh man,
all right, so um, so that's weird. And so people
started asking this question in the seventies. Yeah, it was
in the seventies that people came up with maybe the
first answer to this question. People started asking this question
(24:47):
basically after CP violation was discovered, which is, you know,
just a few years earlier. And then people came up
with his explanation, and it's from Roberto Pechy and Helen Quinn.
There's the nineteen seventy seven and of course very three
is let's think up a new quantum field that fills
the whole universe. Like that's the go to course. Let's
(25:09):
just add more things to the zoo, I know. And
it feels complicated, right, it feels counterintuitive, like we're trying
to simplify things, and to simplify things, we have to
add a new complicated bit. Like yeah, that's all right,
It's that seems counterintuitive. But it's like say you're trying
to describe how an engine worked and you were missing
the pistons. You'd be like, well, this doesn't really make sense.
I'm gonna add one more piece. Oh look, it all
(25:31):
clicks together now it makes sense and so sometimes you
have to add one missing piece in order to make
the whole machine work, or your understanding of the machine
work at least. Right. Well, I imagine it's weird because
you know, really, you guys, I sort of just looking
at some equations on a page, right, But it's like, oh,
if I, if I could add just one number here
would work. But really you're like you're adding a whole
(25:53):
new field to the entire universe just by putting that number.
Some of us experimentalists do more than just look at
pencils and paper, you know, we actually go out and
smash particles and try to make this stuff. Oh sorry, yeah,
you also look at computer screens. That's right. That is
fundamentally different. Okay. My wife used always tease me that
my research was just quote on the computer and therefore
(26:14):
wasn't real research. I see, you don't make chemicals, or
you don't have to wear a lab code. I'm not
wearing a lab coade, So how can it be science? Right, exam,
you can, but it's just strictly cosmetic, that's right. And
so they thought of this field, and they said, well,
what if there's this new field that fills up all
of space, and it's connected to the same field that
(26:35):
controls the strong force, this field of quantum chromodynamics, the
field of the gluons, these particles that mediate the strong force,
and what if it talks to those, It like interacts
with those, and it basically keeps it in line. And
so there's this new field created in a very early
universe with everything else, and it sort of pushes the
strong force in the direction of having no CP violation
(26:58):
I see, but not the other forces like it only
somehow affects the strong force. That's right, only affects a
strong force. And it was created just with everything else.
And then in the first sort of a few moments
of the universe, it pushed the strong force towards having
a zero value for this angle that controls the CP violation.
(27:18):
So not instantaneously like there may be in like a
bill of second there in the very early universe where
the strong force could violate CP. But then it was
sort of like pushed in line by this other field. Really,
but I guess my question is why do you need
this special field? Couldn't did just say that the strong
force that's the way it is, like it was born
with this angle. Why do you need to bring in
(27:40):
like a field that accent it and then somehow disappears. Yeah,
you could go with the non answer right to say,
you know, physics doesn't have explanations, so stop asking questions.
You know, like the numbers just are what they are.
It's not really satisfying. You wonder like why is it
this and not that? Especially when the numbers are a
simple value. I mean, if the number is like point
four to one seven, you wonder what it is. But
(28:01):
when the number is like zero or one's just it
hints at something else happening. It hints at something else
controlling it. Just like seeing those people drive down the
street at all the same speed. You wonder what's doing it?
But I guess you know, like how does it adding
a whole new field help Because we had a whole
new field. Then you have to ask why does that
field exist? Yeah, exactly, just like you have to ask
why do the pistons exist in the engine. But if
(28:23):
you think them up, it does simplify all the parts
working together in the way that you observe. And so
they thought of this field and they try to make
it as simple as possible and very naturally connected to
the strong force, and in in that connection between the
strong force and this new field forced the strong force
sort of automatically to have zero CP violation. It's sort
(28:45):
of like transforming one question into another. You're saying, you know,
why is this angle? Zero gets transformed into why does
this field exist? Sure? Okay, and that's I guess that's
a more comfortable question for you, guys, because because we
like fields, man, because then without it you get out
of a job. Well, also, the field is something we
(29:06):
could discover, right, and so if this field exists, we
can go out and find it, and then you can ask, Okay,
why does that field exists? Why do we need all
these fields? Is it part of some larger strategy. I
don't know, but it is something that we can test
and fine, right, as opposed to like just some weird
property of the strong force. Yeah, you can measure this
property the strong force all day long and say zero.
(29:27):
That doesn't help you understand why it happens. If it,
if it can transform into it's forced to happen because
this field exists, and we can prove that field exists,
then we can start to think about the larger puzzle
and like, well, why this field and does this mean
other fields have to exist? And what does this tell
us about the pattern of all the fields, which is
sort of the larger mission of particle physics is to
understand how all the fields fit together into one. Right.
(29:48):
And I guess it's not totally crazy because that's how
they discovered the Higgs boson, right, Like you thought of
a field to patch something in your theories, and then
you found the particle that belonged to that field. So
it's all sort of been buttoned up. Yeah, exactly. The
question there was like, why does the photon have no
masks and these other particles do have masks? Can you
explain that? And some people were like, hey, just accept
(30:10):
it and move on, man, but Higgs was like, no,
I'm going to create a new field that explains it.
And he was right. And so now we can of
course ask a questions like why is there a Higgs
field dot dot We get to get onto the next question.
And so just like that, this new field creates a
new particle, and that new particle is something we could discover,
all right. And so there's a fun story and by
(30:33):
fun I mean crazy story about how it was name,
how they name axion came about, so tells the story.
So it's it's sort of funny for two reasons. First
of all, Petchi and Quinn, who thought of this field,
forgot to name the particle. Like they came up with
this field, and of course, naturally the field exists, that
it's possible for the field to get like an excited
bundle of energy, which we call a particle. But they
(30:55):
didn't name the particle. And so another physicist came along,
Frank will Check, who's famous and he won a Nobel
Prize for understanding how quirks interact with each other with
a strong force. He decided to name it. He's like, well,
let's think about this field and how we might see it.
And of course he thought about the particle, and then
he had to give it a name. No how he
(31:15):
got to name it, but the particle already had parents.
How can you just go in and like name somebody
else's kids. Say you met a family and they didn't
give their kids a name, you would probably come up
with a nickname for it, right, You wouldn't want to
say that kid's name. I would tell the parents to
give him a name. I would ask the parents, what
do they call what do they say when they want
the kid to come over? Well, then you are more
(31:35):
modest than Frank will Check, which is true for almost
all of humanity anyway. Oh my goodness. So wait they
but did they name? Did Peshi and Helen Quinn name
the field at least? Or did they just say like
a field? Yeah, a field? They just gave it a
mathematical symbol, right. They didn't give a name to the
particle that comes from it. And so you know, if
Frank Wilcheck had been less modest, he would have called
(31:56):
it the Petchy Quinn particle or something, or the field
or what will Check called the field? Yeah, well now
it's called the Axion field. Oh man, he totally took
it over. He totally took it over. And on top
of that, he gave it a totally ridiculous name, like
Axon is a cool name. But he got the idea
when he was grocery shop. Oh no, what happened. He
was in the aisle for laundry detergent and he saw
(32:19):
this laundry detergent called Axion detergent booster, and he thought Axion,
that's kind of a cool name. Oh no, well, he
was what was he thinking, like this particle that I'm
earth surfing and stealing from this other other physicists would
clean everything up pretty well. So, hey, laundry detergent makes
perfect sense. It's a physics booster, so we need a
(32:40):
detergent booster. Yeah, so somebody in some marketing department created
the name for this laundry detergent, which ended up naming
a theoretical particle. But didn't they copyrighted? Can you do that?
That's a great question. Can you name a particle after
like U copyrighting your name in a particle like the
Nintendo Switch particle or like the Netflix particle. Can't do that?
(33:04):
You know, that's a question for our legal department, for
the physics lawyers. You stumped me on that one. Through
the physics lawyers, of whom I am not one. And
you know, there was competition. There were other famous Nobel
Prize winning physicists like Stephen Weinberg. He wanted to call
it the Higgs lit because he thought, oh, this is
only reminds me a little bit of the Higgs boson,
So he wanted to call it things you're gonna say.
(33:24):
You wanted to name it clox or Kleenex or the
tidy no particle um no and accalon sort of stuck.
And you know, these things are not fair, and they're
not always done the right way. Like we talked about
how quirks are named quarks because the famous physicists came
up with the name, even though a young physicist came
(33:45):
up with the name aces before that and it was
sort of buried in obscurity. But these things are not
always done correctly. They're not always given to the people
who to That's right, Yeah, it's not always fair. It's
just sort of like what people end up calling something.
All right, Well let's get into why this action is
super duper cool and why we think it could be real.
(34:08):
But first let's take a quick break. All right, Daniel,
we're talking about the Axon and it got its name
from a laundry detergent, which is I guess not too
(34:28):
surprising in physics, because you know, I'm not impressed by
the general imagination and naming things. But it is a
cool sounding name at least, you know, it satisfies your
transformer principle. Well well, why then did you still Megatron's name,
you know, Optimus Prime? Yeah, maybe they had better lawyers. Right,
the detergent companies lawyers are not as good as the
transformers has bro. Yeah, that is a little bit scarier. Alright.
(34:53):
So you're telling me that this particle is cool because
it would answer the question of why the strong force
the is not violate some of these symmetry conditions in
the universe and that. But it could also be cool
because it explained another big problem. Yeah, there's another big
problem in particle physics, which is where is all the stuff? Right,
(35:14):
we know that most of the stuff in the universe
is not made of quarks and electrons or any other
kind of familiar matter. It's a man of this new
thing that we call dark matter, even though we don't
really know what it is. And just like with the
other sort of physics mysteries, we see evidence for it
and how galaxy spin and how light bends through space,
(35:35):
but we don't know what it is and what it's
made out of. So it's one of the biggest pressing
questions in particle physics, or I think in modern science,
what is the matter of the unit? What is dark matter? Right?
And so it could be axios, it could be laundry detergent,
it could be exactly the dark matter could be scrubbing
the universe. It seems ironic that dark matter would be
(35:57):
something that's supposed to get the stains out reisely. Well,
it satisfies a lot of the requirements you need for
a dark matter doesn't interact with normal matter, so we
wouldn't have seen it. That's what makes it dark. It
has some mass to it, although it's very very light.
So if it were dark matter, you would need like
a ridiculous number of these things. You need like two
(36:18):
hundred billion just to make the mass of one electron,
and we need enough to make five times as much
mass as everything in the universe. And so like, if
axions are the dark matter and they are real, then
we are swimming and swimming and jillions of axions all
the time, meaning that um, if these particles exist and
(36:41):
they explained this strong force problem, they could also be there,
but we wouldn't see them. Like they don't interact with
the electromagnetism. That's right, they don't interact with electromagnetism, and
they do connect to the strong force, but only in
this way that they make the strong force not violate CP.
The field also has some other super duper heavy particles
(37:02):
in it that do interact with a strong force, but
they're so heavy that they potentially don't exist, and so
we don't have to worry about them. And so effectively,
axions are totally inert except for the fact that they
have a small mass. And so if they have this mass,
then they contribute to gravity. And that's what dark matter is.
It's something mysterious out there that's adding gravity to the universe,
(37:24):
and so it could be the act All right, well,
would that be sort of a coincidence that we have
this particle and it just so happens to fill in
the blankford dark matter? It would be amazing, Like who
wouldn't want to solve two big problems in physics at once, Right,
you think of this particle to solve one problem, and boom,
it turns out to solve the other problem at the
same time. You can collect two Nobel Prizes in one trip.
(37:47):
I mean that sounds pretty. You get to like, do
you get too in the same ceremony? I wonder I
think you have to come back the next year. I'm
not sure, but that's attractive but also makes you a
little suspicious, Like we thought this particle up to explain
the strong ep problem, and then we have this other problem.
We're gonna try to sort of squeeze this particle into
solving the dark matter problem. It actually sort of reflects
(38:08):
something else about the dark matter problem, which is that
we're getting a teensy bit desperate. Like we thought we
would have figured out dark matter by now. We had
better ideas for what dark matter could be, these weakly
interacting massive particles stuff like that, and none of that
has really panned out, and so now we're sort of
like dragging along the bottom of the barrel looking for
other ideas that might explain dark matter. And so that
(38:31):
sort of led to a resurgence and interest in the axons.
People think, wait a second, what about axons? Maybe those
could be the dark matter. Like so desperate, you're reaching
for the non brand laud exactly what you're saying, that's
exactly where we are. And it could also maybe solve
another big problem, right it could it could solve another
big problem. That was a really fascinating paper out there
(38:52):
last year that talked about those first few moments in
the universe when this field was created and it forced
the strong field to not violate CP and it turns
out when it did that, it had sort of two directions.
It could go sort of like imagine a marble in
an upside down hat, and it's rolling towards the bottom,
and that's how it forces the strong force to not
(39:13):
violate CP. But if instead of just rolling strength down,
what if it had like a little bit of a kick,
so it sort of went around in a circle and
then relaxed to the center, then it could have done
it clockwise or counterclockwise. Oh boy, it's like another symmetry.
It's another symmetry. And it turns out if it goes clockwise,
then the universe is filled with matter, and if it
goes counterclockwise, the universe is filled with anti matter. What
(39:38):
it's like flipping a coin. We could have been made
out of antimatter. Yes, And that's a big question in physics,
is like why is the universe made out of matter
and not antimatter? And we don't know. And it feels
like a coin was flipped and it could be that
this was the coin. It was a laundry detergent coin
that determined the entire universe. Yeah, and so the axon
(40:00):
could solve this other problem also, so it really could
be key to a lot of these big, big mysteries
in particle physics. And I guess you're because I imagine
you were saying that this is not the only idea,
like this is not the only field or particle that
people have dreamed of, but this one is somehow more
attractive because it's sort of makes more sense, well, because
(40:22):
the other ones have been sort of ruled out. You know,
you have your first idea, you go look for it,
the experiment says no, sorry. Then you go for your
second idea, you know, and you just keep looking through
ideas until you find one that the universe says yes to.
And so that's sort of led to a resurgence. And
you know, also theoretical physics, there are trends, there are fads.
People get excited about an idea and they work on
(40:43):
it furiously, and then they get bored with it. Somebody
else comes up with a new idea, and so the
idea sort of have cycles. You know, People get bored
of an idea, put it aside, and then twenty years later,
some new young woman says, hey, I have found a
new way to use this old idea, and then everybody
gets excited about it. Again, it's a human endeavor, all right.
So then the action is is trending is what you're saying,
(41:04):
Like it's it's having a popularity, surgeon popularity. And so
I guess the question is is it real? Like does
it actually exist? And can I find it in places
not my laundry the diurgent aisle at my grocery store. Well,
we don't know, but there are experiments out there to
look for it, sort of two different categories of experiments
that both use magnetic fields. The idea is that the
(41:27):
axion is still or like a photon and it doesn't
interact with photons and normally, but it turns out that
if you put the axion into a super duper strong
magnetic field, then sometimes it will turn into photons. Wait,
a magnetic magnetic field can cause particles to change. Yes,
the magnetic field will change the way the particles interact. Right,
(41:49):
it has energy in it, and if those particles can
feel photons in any sort of way, then they can
get enhanced and they can change the way they decay.
And so the axion and if it's in a chamber
that sort of resonates with it and it's that chamber
is filled with magnetic field, and this magnetic fields is
like a hundred and fifty thousand times the strength of
(42:10):
the Earth's magnetic field, then it could sometimes turn into
like little microwave photons. So they have this cavity up
in University of Washington where they have very cold and
they have a very powerful magnetic field, and they're just
listening for a little microwave blip, so that we can't
see them, but they might turn into things. We can
see them precisely into in need these weird conditions, in
(42:33):
very strange, very strong conditions, they might turn into photons. Really,
you can predict that with the equations. The equations say
should happen if you get the magnetic field at the
right frequency and you get it down to cold enough conditions,
and they've been running it for a while and they
haven't seen them, but they're sort of like tuning the
magnetic field, like are they over here? Are they over there?
(42:53):
And so far they haven't seen anything, but it's sort
of getting more and more powerful. The device pretty cool.
All So that's one way. What's the other way that
we might see them? The other way, sort of the opposite,
is to try to turn light into axions, Like instead
of having axon turn into photons, turn that around. Take
a beam of light and try to turn it into
axions by putting the light. Yeah, like make light disappear. Yes,
(43:17):
And so this experiment is called light shining through walls
because you basically have a wall and a really strong
magnetic field and then a beam of light and the
ideas maybe the light will turn into axions which can
then pass through the wall with no problem, which will
then turn back into light and you can sort of
like have your light, you know, passed through the wall
(43:38):
by phase through the wall, by becoming an axon as
it's going through the wall. I feel I feel like
you're getting to the point where you're like, we need
ideas or what's what's this is? This is a comic book?
What there was a superhero that can go through walls?
Oh that sounds like a great idea. Yeah, well it's
pretty cool because if we figured out then we could
actually build beams of light that go through walls. Right.
(43:59):
So also sort a cool experiment because you just need
like a light beam and a wall and then you
just look for light making it through the wall. Right,
So it's pretty dramatic, seething magical X rays. Yeah yeah,
turning light and X rays making them penetrate just like
X rays. And it's pretty fun, you know, to see
these experiments. These are clever ideas, These are wacky ideas,
(44:21):
and personally, I never expect these experiments to actually discover
the axion. What though, isn't this your field? This is
my field? Yes, but the accon has always seems sort of,
I don't know, out there to me, like too crazy.
An idea just feels like a little bit out there
in left field, like yeah, it's a little too sutsy.
(44:41):
Like I've read this interview with Helen Quinn, one of
the two people who came up with the original idea,
and even she's a little amused that this idea is
still lacks She's like, I don't know what all the
fuzzes about. Direct quote from her is Roberto and I
spent a few months cooking up this theory, and now
the experimentalist has spent forty years look for it. She's
laughing at you, Daniel, It's like she's she's amused by you.
(45:05):
The whole thing was a joke to begin with. What
you guys doing wasting your time, Like that's what. We
didn't give it a name. It was all a big
practical joke, and then we planted the detergent for Frank
whil Chick to find it using their time travel device, right,
their magical X ray life. But it's fun, and you know,
sometimes an idea can begin from a silly place, just exploring,
(45:28):
just fuxing around with the math, and then turn into
something real. I mean, if the axion is real and
it solves these big open questions in physics, then that
would have been a productive few months cooking up that
crazy theory and productive forty years because you know, like
the it's almost like the Higgs boson, right, do you
predicted it? And like forty years later they found it. Yeah,
it took almost fifty years to find the Higgs. So
(45:49):
sometimes you come up with a theory for a particle
that's really really hard to find. It's not always easy
to go out and just like look for this thing,
even if you know what it's supposed to do and
how it's supposed to look, creating those conditions to find
it is not always easy, especially if it's elusive. I mean,
if it's the dark matter. Then it's been hiding for
a long time, and and the stakes are pretty high, Like,
if you find it, it would explain to so many things,
(46:11):
including dark matter and antimatter and strong CP problem. Yeah,
it would really close off a lot of big open
questions in physics. So from that point of view, I
sort of hope it is real because they would be
a fascinating inside into the universe. And then, like as
always with physics, when we get to ask the next question,
like all right, well, why is there an axion? What
does that mean? Is there another axion? You know, the
(46:34):
whole spectrum of axion particles, And so the questions never
really end right whenever there are lawyers that the Axon Corporation,
they're like just waiting for you guys to discover it
to give them that marketing boost in popular culture, or
that's when they're going to see right there you go,
They're gonna they're waiting, like, we own this. You can't
(46:54):
you can't make X rays light special laser beams without us.
That's right, We demand you pack up all your axions
and boxes and send them to us immediately. Alright, Well,
I think as usual, this just points to the things
we don't know and how you know, science is actively
still trying to explain the universe. That's right, And then
a hundred years we could look back and think, what
was it like before physics knew about the axion particle
(47:18):
or the chlorox particle or whatever it is we're going
to discover in twenty years, but before we know it,
it's just an idea. It feels very different to be
on the ignorance side of a discovery than on the
knowledge side, because you never know what could turn out
to be true. That's right, because the universe is no
strangers to weirdness. All right, Well, we hope you enjoyed that.
And the next time you're going down the grocery store
(47:40):
laundry detergent, I'll look around. You might discover a new
particle that explains the universe. Keep your eyes open, or
at least discover a cool name for somebody else's good idea.
You go. Thanks for joining us. Let's see you next time. Yeah,
(48:03):
thanks for listening, and remember that. Daniel and Jorge Explain
the Universe is a production of I Heart Radio. For
more podcast for my heart Radio, visit the i Heart
Radio app, Apple podcasts or wherever you listen to your
favorite shows,
Hosts And Creators
Daniel Whiteson
Kelly Weinersmith
Popular Podcasts
United States of Kennedy
United States of Kennedy is a podcast about our cultural fascination with the Kennedy dynasty. Every week, hosts Lyra Smith and George Civeris go into one aspect of the Kennedy story.
Stuff You Should Know
If you've ever wanted to know about champagne, satanism, the Stonewall Uprising, chaos theory, LSD, El Nino, true crime and Rosa Parks, then look no further. Josh and Chuck have you covered.
Dateline NBC
Current and classic episodes, featuring compelling true-crime mysteries, powerful documentaries and in-depth investigations. Follow now to get the latest episodes of Dateline NBC completely free, or subscribe to Dateline Premium for ad-free listening and exclusive bonus content: DatelinePremium.com