How was antimatter discovered?

Learn about antimatter with Daniel and Jorge

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Episode Transcript

Speaker 1 (00:08):
Hey, or Hey, did you know that there are physics truthers? What?
I know there are particle theorists, but I didn't know
there are conspiracy theorists. The conspiracy theorists some of them
don't believe that antimatter is a real thing, so they're
anti antimatter. All matter matters. What do they just think

(00:29):
that you made up this concept of antimatter? Yeah, it
turns out a lot of people don't think antimatter is real.
They don't believe in it. Well, maybe they just need proof,
you know, maybe they're not crazy, they're not bananas. Well
it turns out the proof is bananas. Who are bananas antimatter? No,
but it turns out bananas produce antimatter. Hi am Jorge,

(01:08):
I'm made particle physicist, and I'm Daniel. I'm a cartoonist,
but I'm not the author of PhD comics. And those
are the anti versions of the real us. The host
of this podcast, Daniel and Jorge explain the universe de
production of My Heart Radio. Although since you've been listening
to me talk and talk and talk for all these years,
by now you're basically a particle physicist. That's right. I

(01:30):
feel like I talked to you more than you probably
talked to your grad students, so probably should give me
a PhDs. Don't tell my grad students that do you
allow them to hear hear this podcast? Do you let
them out of their basement every once in a while.
I'm curious if they listen. I think I've mentioned it
to them. Actually, some of them appear in our interviews
from time to time. Oh, I see people who can't.

(01:55):
That's right. I wonder if it's extra stressful for them
if they say no, Are you going to judge them
based on what they know or don't know? No, I
think it's extra stressful if they say yes, and then
I asked them a particle physics question they really should
know the answer to. Then they're on the spot, and
you have them on tape. I have them on tape exactly,
but the podcast universe to listen, that's right. But the

(02:15):
goal of this podcast is not just to embarrass my
graduate students and put them on the spot, but to
teach all you people out there about the amazing universe
of particles and stars and bananas that we all get
to live in. That's right, All the things that exist
out there in the universe and all the things that
maybe don't exist or that exist in a constant state

(02:35):
of denial, that's right, or things that currently only exist
in the minds of particle theorists, ideas about what the
universe might be like that we don't know if they
are real, right, because even the things that might not
be real tell us a little bit about how things
really are and why they are there where they are right,
that's right. And in physics we have this sort of

(02:57):
cycle of people making predictions and saying, what if the
universe works this way, and then people going out to
check and say, hey, it turns out you were wrong.
Go back to the drawing board. And there are many
many beautiful theories out there that people came up with
that they were convinced we're real, but then we're confronted
by the evidence that they're not. That's right. There are
conspiracy theorists. Even in physics. There are people who are

(03:20):
skeptical about the things that physicists have found. Right, even
physicists themselves who are skeptical, Well, it's our job to
be skeptical, but we like to think that's sort of
a reason skepticism. You know, when presented with the evidence,
we don't come up with an even more elaborate conspiracy
theory to deny it. We accepted, we move on. But
it's true that some of these ideas that are in
the minds of physicists, they can be kind of hard

(03:42):
to accept, and some people still out there think that
they're just ideas, that they're not actually real, right, because
it's kind of an interesting cycle in physics where you
might see something in nature and then you come up
with the theory, and then you do an experiment that
validates or disproves this theory, and then you come up
with more theories, and so it's like this weird and
interesting loop, and so it's hard to tell sometimes where

(04:05):
ideas come from. Yeah, especially in particle physics, we seem
to obscolet between two modes. One is where theorists are
leading the field, where they have ideas for what they
think is happening in the universe, and then experimentalists have
to go out and basically check those ideas. And the
other mode is where experimentalists are taking the lead, where
we're out there finding crazy stuff nobody understands and theorists

(04:27):
are scrambling to keep up to explain all the bizarre
stuff that we've uncovered. So what do you think it's
that determines who's taking the lead. Is it like just
who has more free time in their hands to play
around and discover things, or who's more suspicious of the other.
It's just up to nature. It's just up to how
much stuff there is to discover. You know, in the

(04:48):
fifties and sixties, they were discovering a new particle every
time they turned on the accelerator. They called it the
era of the particle zoo. Whereas these days it's like
decades between particles, and that gives the theorists a lot
out of time to be creative, to come up with
new ideas, to say, maybe it's this, maybe it's that,
because we don't have anything to sort of constrain them
right now, we're in a really fury driven mode of

(05:10):
the field. Is there a song for the particles? I
feel like there should be a song particles, particle zoo
doing the things particles do. There you go wow on
the spot, jingle making that's right by. They might be
particle physicists PhD and jingle engineering, granted, but it's interesting

(05:32):
history right in the fifties, we were discovering new particles
nobody understood. And in the very early days of particle physics,
like the first particle was discovered, right, that wasn't predicted,
it was discovered, and then the photon was like thought
up to explain an experiment that people had seen. So
the very beginning it was driven by experiments. But these days,
of course it's driven more my theory. And so today

(05:52):
we'll be talking about one such thing that has been
seen or had that some people have seen in nature
and physics, but maybe some physicists don't really believe that
it exists. Oh, I think most physicists believe it, but
I just wonder about the general public. Oh so it's just, um,
you say true things, you mean physicists or people? I

(06:14):
mean people, because physicists or not people. Is that what
you're saying. You just trapped me. You totally led me
into a trap there, Daniel, Are you a person or
a physicist? Take one? No, I think that you know,
this is really fascinating because it's one of the first
things that was ever predicted before it was seen. This

(06:36):
is the first time somebody said, maybe this crazy new
thing does exist out there. In the universe, somebody go
look and sort of sort of the dawn of the
New era. And it's taken a long time for people
to believe that it's real, and some people out there
still don't. So I guess at some point this was
a topic where some people thought it was true, but

(06:57):
a lot of physicists maybe didn't think that we would
see it or that it would be proven to exist.
That's right. Between the prediction and its discovery. It was contentious,
and it's a pretty interesting topic because it talks about
a huge part of the universe that is both intriguing
and super dangerous. Yeah, and fascinating. And you hear all

(07:18):
about it in popular culture, like it's everywhere. It's even
in Dan Brown novels, so you know it's got to
be cool. Oh man, it must be true then if
it's a Dan Brown never Yeah, I think those are
all heavily researched. The Da Vinci particle. All right, Well,
so today on the podcast, we'll be asking the question,

(07:44):
how do we know antimatter is a thing or an
anti thing? What's the correct way to how do we
know antimatter is not a thing? Or how do we
not know that antimatter isn't not a thing? That's put
it more more negative, No, I and anti that kind
of use of language, Daniel. I think that often the
history of particle physics and the topic of particle physics

(08:05):
is framed from a theoretical point of view, like what
is our understanding of the particles? That it's out there?
And that's cool, But for me, I'm an experimentalist. I
want to know, like, how do we know these things?
Like you say, these particles exist, how do we know
that it's real? What experiment? What? What the thing happened
that proved to us that it had to be there,
that it's part of the universe. So we did a

(08:26):
podcast episode about how do we know even particles exist?
About the electron and how do we know photons exist
in this kind of stuff? And and why are their muans?
And so this is sort of in that series of
like telling people about the moment when we confronted something
that proved to us that this new thing had to
be a part of our universe. Yeah, and so antimatter
is a is a word or two words put together,

(08:48):
and we kind of know it's a thing, but we
were wondering how much people out there know about it,
or that they know that it is a thing and
not just one of those crazy physics ideas that are
floating around. Yeah. So I went around and my goal
was to ask people if they knew how anti matter

(09:09):
was discovered. But I had to back up because it
turns out a lot of people didn't even know that
anti matter actually had been discovered, so they didn't know
that it was a thing. Yeah, that was so surprising
to me. But listen to these interviews and thinks to yourself,
do you know how we discovered antimatter? Here's what people
had to say. I know about about it, I don't
know how they discovered it now, No, I don't have

(09:31):
heard of it, and like science fiction and stuff, um,
but I don't know how the logistics of it would
even be possible. So I'm not too sure. But I know,
like the phrase I've heard it like a lot of
is it a real thing or just science fiction? I like,
it's kind of like theory, So it's not too sure.
I think they are because I read it something about

(09:53):
it keeping the universe from expanding too fast? So how
do we know anti matter is a real thing? Like?
How was it discovered. I don't know exactly, but my
best guess is that that it could be shown through
like how the universe expands. But it seems like it's
being limited by a certain the end. It's predicted to

(10:16):
the antimatter Right now, it's all theoretical, isn't I don't like,
have we actually done anything with like large hangar clider
as far as any matter? Yeah, I'm not sure. I
don't know. I don't know what that means for now.
It's it is just an idea surreal thing. Okay, how
do we know it exists? By calculation? To make your

(10:41):
to accommodate the amount of our understanding of matter in
the universe? Do you think matter? I thought there was
some anti matter dirt matter connection, Okay, not that I'm
aware of. Don't know. Don't antimatter Well, it's like I'm
kind of doesn't exist. I mean, if it were. No, wait,

(11:04):
because it goes to show that I know nothing about
particle physics. But there's something. I mean, listen to my
podcast for office. I would love to listen to your podcast,
and I'm sure that that there's something I would learn
from it. Antimatter is a real thing as a it's
a counterpart to a regular matter rights. How do we

(11:26):
know it exists because to create matter, you have to
also create antimatter, and it's been a proven reaction, and
we know that it exists despite not being able to
necessarily detect. I have not heard of that term actually,
all right, So it sort of seems like people are

(11:47):
skeptical about it, or they weren't. Not a lot of
people seem sure that it is a thing, Like they
talk about it like it's a theoretical thing, or it's
not proven, or it's an idea. Maybe actually I just
realized maybe it's because it's in a Dan Brown novel
and they thought, oh well, then it must be b Yes,
thank you, Dan Brown. And that should be called like

(12:10):
anti science communication anti science. I don't think he claims
to be a scientist or claims to be a work
of nonfiction. No, But you know, when he made that movie,
of course, we're referring to Angels and Demons, Dan Brown's
novel about an anti matter bomb, in which the science
is mostly right actually about antime matter. But when they

(12:30):
made yeah they did, um yeah, yeah, the science in
there's is mostly correct. But they made that movie. They
filmed it actually where I was working at the time,
because I was at Sern and they were filming the
movie at Stern and uh, and then I wanted to
get a camera. What's that did you get? Did you
get a camera? Next? With Tom Hanks? Only the most
v I P of v I P has got to

(12:50):
give Tom Hanks a tour. So I was like, not
even in the top five list of people who would
get to have lunch with Tom Hanks, unfortunately, But now
now you now you would be making the top Yeah,
I'm really moving up. But the cool thing was when
I watched the movie, they had taken our like normal
boring workspaces, which which is basically just a bunch of

(13:12):
computers and screens, and they had science fictioned it up,
so people had like cool heads of displays and like
fancy interfaces with their computers, las, lasers and scanning devices.
And I thought, that looks pretty cool. We should upgrade
the way our office works to look like the movie.
You're like taking your pocket and looking at a metal key.

(13:33):
You're like reality versus world. But it was cool to
see what like Hollywood's best designers would do with my office.
Pretty cool, all right, So it seems like people are
not quite sure that it's real. They think it's maybe theoretical.
Do you think maybe they were confusing antimatter with other
things like dark matter or yes, absolutely, I hear that

(13:55):
a lot. Actually, I think that people know that there's
something out there is a miss dearious counterpart to matter.
And it turns out there's sort of a few mysterious
counterparts to matter. Right, there's this whole antimatteric thing. It's
dark matter that there's super particles, and so there's antimatters,
there's quasi matter, there's matter, there's exotic matter. You know, yeah,

(14:17):
I know that's a real potentially could be a thing thing.
Splatter matter, there's mats matter, and now you're making me
matter matter um. And so there's sort of a lot
of different ideas to keep track of. And so if
you're not like a particle physicists like you are, then
maybe it's hard to keep your finger on which ones
are real and which ones are theoretical. Right, And I

(14:39):
have to say, antimatter does sound a little ridiculous, does it.
It sounds very like nineties fifties science fitching. It's antimatter,
it's like matter, but it's anti The whole concept is absurd, right,
But as we said on this podcast, absurdity is no
obstacle to reality. Right. Turns out the universe is kind
of bonkers. Yeah, I feel that way every time I
read the news every morning these days. It used to

(15:02):
be just physics, and now it's also politics. Is bomb beers.
But anyways, um so yeah, let's talk about anti matter.
And we have a whole episode about anti matter. If
you scrolled through our archive, you can find that episode
and learn a little bit more about it. But here
we'll just kind of go over quickly about what it
is and how it's not actually dark matter. That's right.

(15:22):
Antimatter is not dark matter. It's a whole other, enormous,
fascinating puzzle about the universe. Anti matter is a statement
about particles and patterns. It's noticing that particles come in pairs.
And so some of the particles that we've discovered, the electron,
the muan, the corks, there's another particle that looks just
like them, except it's the opposite in a couple of ways.

(15:46):
And so, for example, the electron is a particle. We
know it, we love it, we're made of it. It's
in ice cream. And there's this other particle called the positron,
which is just like the electron accepted, has a positive
charge instead of a negative charge. It has other negative
things about it, right, like the opposite spin or the
opposite quantum color, and other kinds of charges, right that

(16:07):
are different. Some of the other charges for the for
the forces are opposite. The electron actually doesn't have a
color because it's doesn't feel the strong force, but it
has the same mass and spin. So the positron are
the same in mass and quantum spin. They're both spin
one half, and they have exactly the same mass as
far as we know, but they have the opposite electric charge.

(16:27):
And so you might just say like, oh, well, it's
just a different particle, and it is. It's a different particle,
but there's definitely a relationship there. So we group them together.
And this is what we do all the time in physics,
and especially in particle physics, is we're looking for patterns.
We're looking for, you know, relationships that help us simplify.
We're looking for symmetries that give us insight. And so
it's interesting not just because the electron has this weird
partner particle, But so does the muan, and so do

(16:50):
all the quarks, right, and and we call it matter
and antimatter because the ones we call matter are the
ones that make of most of the things we see.
A round is right, like positrons and anti mu as
an anti quarks. I'm not made of any of these things.
I'm made out of the regular versions, the provisions. That's right,

(17:10):
you're made of the regular versions. But you're right also
that we call them regular versions because they're familiar. They're
like the first ones we encountered, because they make up
the world we know, and so there's nothing anti about
the other ones. They're just sort of not the first
ones we found. Maybe maybe a different word might be
like mirror matter or symmetric matter that's actually already taken.
There's a whole other theory about mirror matter we can

(17:32):
talk about another time. But it's a crowded field of
terrible names for particles, and you're running out of English
words to append to your existing physics concepts. Banana matter taken.
Banana matter is not even an idea yet, not until
this podcast comes out. Is banana matter not ever a
phrase anybody's effer Herd in their mind. But it's fascinating
because it seems to be like a thing. It's like

(17:52):
a symmetry in the world, you know, like a lot
of these particles which exist, there is also this other
one of them in the same way that we notice
that electrons and muans and taws have a relationship, right,
They all have the same electric charge and the same
weak interaction, and they're organized in a similar way, but
they have different masses. So it's like these different directions

(18:13):
along which patterns sort of form. All these particles are
kind of different versions of each other, Like one of
them has a little bit of this more, or this
one has the opposite of that more. But they're all
sort of particles that we know and love because some
of them make us who we are, that's right, And
we're tempted to define one of them is like the
normal one. But again that's just the first one we discovered.

(18:33):
It's like, you know, what's real chocolate, dark chocolate or
white chocolate. You know, maybe if you grew up in
a family or white chocolate was the first thing you ate,
then dark chocolate would seem to be like the anti chocolate,
do you right? Yeah, that I think we should we
should do that, just call it anti chocolate. Um. And

(18:54):
and and remember also the antimatter is has positive mass,
right as far as we oh, it's made of the
same kind of stuff, and so it is antimatter because
it has the opposite charge. And if you collide matter
and antimatter, they interact and turned into light and turned
into energy. But in that sense, they're just more matter.
It's just you know, they have this relationship. We could

(19:17):
have called it something other than antimatter. We could have
called it, called it oppositely charged matter, or something that's
a little bit longer to fit into it didn't focus
group as well. Yeah, alright, so that's what antimatter is.
And there's this whole mystery about how most of the
universe seems to be matter and not antimatter, which we

(19:37):
got into into in our last podcast about antimatter. But
in this case, this one is more about how we
discovered it and how we know that it actually is
a thing. Right, that's right. The history of antimatter is
like almost a hundred years old now, um, it's sort
of surprising, but positrons, the first antimatter particle ever discovered,

(19:58):
were found You know in nineteen thirty two, so we've
known about them for a long long time, which kind
of surprised me that people still don't necessarily believe that
they're a thing or are aware that it's a thing,
because it's been a thing for decades. People, Right, Well,
I think antimatter is anti celebrating birthdays, so that's probably
why maybe nobody has noticed. But let's get let's get

(20:20):
into whether or not antimatter really is real or theoretical,
and how we know that it's real or anti real,
whatever the case may be. But first let's take a
quick break, all right, Daniel, So antimatter is real, whereas

(20:46):
an anti real or anti fake, which makes it real.
I'm so confused. It's really really anti anti real. So yes,
it's real. That did not help. Okay, So it's real
in the sense that not only can it exist in theory,
but you can actually like see and touch antimatter. You

(21:09):
can see in touch antimatter. I don't recommend actually touching
any antimatter because it's quite reactive. But it is a thing.
And you know, there's sort of two ways something can
be a thing. One is it's in the list of
particles that can exist in the universe, like the potential particles,
and the other is that it's actually made, that it
really exists. You can imagine a universe where that's cold

(21:33):
and dead and the only thing in it our photons,
for example, and you could in theory and that universe
have electrons. It just don't exist. Right, So one thing
is like being on the list of potential particles, the
other is actually existing an antimatter is both, but started
off on the theoretical list and then people actually found it.
You mean, people looked at the equations of the universe
at the time and they said, you know, we have

(21:54):
a little pocket here where there could be like an
electron with a positive charge. Like, there's nothing that would
prevent the equations from making this real. So you're saying
that's one way that something can be real if it's there,
if the equations point to it as being possible. Yeah,
and more than just the equation saying it's possible, you

(22:14):
could prove that it exists. But it doesn't have to
always actually exist, you know, like the Higgs boson, right,
the Higgs boson. We know it it's a thing, but
it doesn't actually like get created very often you know
you have you have specially need very special circumstances to
actually make one. So it's sort of like knowing that
the recipe works and actually making the cake. Right, It's

(22:36):
like unicorns can exist, but maybe they're just technically aren't
in right now the unicorns, what's the difference here, Daniel?
But and the matter is real. It occurs naturally in
cosmic rays. You don't actually need like a particle collider
or special physics lab to make it. It's created in

(22:56):
collisions in the atmosphere. Um, every time you have rate,
you active decay, you can create antimatter. Sometimes these decays
will create anti neutrinos or anti electrons or stuff like this.
Really in our atmosphere, we're getting rained down. Wait, it's
it's like regular matter is coming from the Sun as
cosmic rads hitting the atmosphere, and then in those collisions

(23:20):
you're saying antimatter is produced. That's right. Antimatter and matter
can turn into each other, right. Um Photons, for example,
can turn into a pair at an electron and apositron
one is matter? What is antimatter? All you have to
do is follow the rules of physics, which say, like
conserve electric charge. But if you have photons, they can
turn into matter and antimatter. So you have in the

(23:41):
atmosphere because of cosmic rays, you have all these crazy complicated,
high energy collisions, and some of those just turned into
antimatter particles. Does that mean we're constantly and currently being
rained down upon by antimatter? Absolutely? It is antimatter rain.
I think that is a song by Prince wasn't it? Yeah,

(24:02):
anti Prince Um. But the wait I thought it was dangerous.
How can I be getting rained on by antimatter and
not exploding like you said I would? It is dangerous
in high quantities, but there's not that much antimatter, Just
like you know, there's radiation coming from the upper atmosphere
all the time, and radiation is also dangerous. You know,

(24:24):
protons and muans that go through your body have the
opportunity to damage your DNA, but there's not that much
of them, And so the higher you go up in
the atmosphere, the more there there is just particle radiation,
and some of that is antimatter. So what happens if
a positron hits your arm, Well, it encounters an electron
and it turns into a photon. That photon has the

(24:46):
energy that's the equivalent twice the mass of the electron
because all that mask got turned into a photon. But
that's not that much, so you know, you one photon
gets created. Should I be wearing anti sunscreen? Then said,
there's no sunscreen. You can wear it to protect your
things that matter or just antimatter. Just make me glow
in a way that's desirable. Antimatter. It gives you an

(25:09):
anti tan, So actually what you want to do? Yeah,
you do look brighter, I guess in a way, so
it's almost like you're The amazing thing about antimatter, though,
is that it is really energy dense because it converts
all of the masses inside of it into energy. So
if you had, for example, like a raisin's worth of antimatter,
which is a lot more than one positron, right it's

(25:30):
ten to the twenty three particles or something, then that
would be as much energy as a nuclear bomb exploding.
But again that's a much bigger dose. And in the
atmosphere you get you know, a few few positrons at
a time, and it's not just the atmosphere. Your favorite
snack actually is an antimatter of factory. What. Yeah, a

(25:50):
random banana has potassium in it. As we've mentioned before,
potassium is unstable and it decays radioactively and produces one
positron every seventy five minutes. One positron, Like a sitting
banana will shoot out a positron or does it get
caught by the other you know, banana electron banana on.

(26:16):
It depends. I guess where it gets produced. If it's
produced in the skin to the banana, it will shoot
out into the air. But of course positrons don't last
very long because they interact with electrons. But yeah, your
favored fruit, whether it's sitting on the table or you know,
in a high speed banana accelerator or whatever you do
with your bananas, produces about one positron every seventy five minutes.
It doesn't get stopped by the peel electrons electron. Yeah,

(26:38):
if it's produced in the center of the banana, then
it could. But if it's produced near the edge, and
then you could make it out of the banana into
the air. Well, maybe that's where I get my superpowers. Dan,
You get antimatter, you get that banana's proportional strength. Yeah,
there you go. I can make anyone slip and fall.
That's superpower. I can't make anyone uncomfortable with my ban

(27:00):
ant a chewing. All right, Well, let's just slide on
past that discussion. Yeah, alright, So antimatter is real. It
is a thing. It's all around this. In fact, you're
probably baild in antimatter even though you maybe didn't know
it um. And you can also like make it in
a lab, right, like a certain you guys have been

(27:20):
making anti protons and anti hydrogen for a while, like
you have an antimatter of factory there. Yeah, that's right,
And the reason is that we're curious about it. We're
curious about like how symmetric our matter and antimatter. You know,
For example, can you make an anti proton and pair
it with an anti electron to get anti hydrogen? Does

(27:40):
chemistry work for antimatter? You know? Can you get enough
of it to test its gravitational properties? We don't even
know if antimatter feels gravity the way matter does, or
or if it feels like anti gravity because you just
never made enough of it. Really, the equations don't tell
you whether it should have mass or anti mass. Yeah,
because it's really hard to measure the gravitational force on

(28:03):
a particle because it hardly has any mass. And in
the history of particle physics, we've made something like twenty
nanograms of anti matter ever total, and so it's pretty
hard to measure the gravitational effect of such a tiny scrap.
But you have made anti protons and anti hydrogen, which
is pretty cool, right. It's like a hydrogen, but the

(28:25):
complete opposite. Yeah, And as far as we can tell,
it works exactly the same way as a hydrogen atom.
So they get into a bound state, they can get excited,
they emit photons. It's exactly the same. So it's super
fascinating either to learn that they're different or to learn
that they're the same, you know, and it brings up
all sorts of interesting questions like why why is there antimatter?

(28:46):
It seems like such an interesting clue, Like why does
universe have this weird reflection? You know, it has all
these reflections. I love all these symmetries and particle physics,
but each one should tell us something about the universe.
They're a big, deep clue that says, here's something fastening
that's going on. We just don't know what it means, well,
you know, some people are just really contrarian, you know,
and to mabe, the universe is just just being anti

(29:08):
anti for no reason other than to just be anti.
But if it, But if antimatter exists, then why aren't
there other sort of reflections? You know, Why can't you
have all the same particles but with different spin. Oh
well that's supersymmetry, you know, why this reflection not other reflections? Anyway,
it's kind of stuff that makes me wonder do you

(29:29):
think it's these other mirror images exist? Do you think
they would have better names in physics, like actually good
ones because they're to be the opposite. Well, they can't
have much worse names. So there you go. All right,
Well it does exist. It's real. You can we can
make it in the lab. It's my banana makes it

(29:50):
on a daily basis. And there are still a lot
of open questions about anti matter. So now let's talk
about how it was discovered, because that's a pretty interest
seeing story as well, and what it could mean for
the future of the universe. But first, let's take another
quick break. Okay, Daniel, So how is antimatter discovered? Were

(30:22):
they not looking for it and found it that would
be a great story. No, and that matter is sort
of a theoretical triumph because it happened actually very similarly
to the joke you made earlier, or the comments you
made earlier about people sort of noticing a gap in
the equations. What happened was the Paul Drac who's famous

(30:43):
theorist of around the beginning of when quantum mechanics was
was being formed, he was taking the Shortinger equation, the
equation that describes the motion of particles, and he was
trying to make it work for really fast moving particles.
He was trying to fold in relativity and quantum mechanics,
which amos is very hard to do, but he was
able to actually unify um, quantum mechanics, and special relativity

(31:06):
the laws that tell you what happens when things move
really really fast. So he came up with Yeah, he
came up with a new equation. It's called the Dirac equation,
and it's like the relativistic version of the Shortinger equation.
Shortinger equation tells you what happens for quantum particles that
are not moving that fast. The direct equation tells you
what happens when quantum particles are moving fast enough that

(31:28):
relativity kicks in. So he had this awesome equation already
a triumph, right, and it turned out to be true. Right,
This theory is as far as you know now. Yeah,
and that's amazing, right, direct unified special relativity and quantum mechanics.
And remember we've never successfully unified quantum mechanics and general
relativity theory by like bending space. That's still like to

(31:51):
be done. So folks out there looking to make a
big impact on physics that's been an open problem for
a hundred years TVD to be discovered. That's right. But
then Derek looked at this equation. He's like, this is
something weird about this equation. He noticed that the equation
worked for a negatively charged particles like electrons, but it
would also work for positively charged particles. They thought, that's interesting.

(32:13):
Did did the equations have a pocket or like an
empty space for an anti electron? Or he just figured
out that this equation that we think describes the universe
could also work for something that looks like an anti electron. Yeah,
it's an equation with two solutions, just like you find
all the time and equations that have like squares in them,
like X squared equals nine, while there's a solution there, right,

(32:36):
X equals three, But there's another solution X equals minus three, right,
because minus three ties minus three is also plus nine. Yeah, exactly.
And so he noticed that his equation described electrons as
we know them, but it also described something else, something
we hadn't seen before, another particle with positive charge. And
it's for exactly that reason that there's a squared in

(32:59):
his equation, and it allows for you know, particles of
either charge to satisfy his equations. And so he predicted
that this would work for an anti electron. But did
he predicted for other anti matter particles or just just
for the anti electron? Oh? Yeah, the story gets exciting,
But first he started small. He's like, you know what,

(33:19):
I think this is real? And I wonder like what
went through his head there? What makes him think, Oh,
that's not just a mathematical oddity. I've discovered something about
the universe. Because a lot of times we have equations
that describe things and we just sort of toss out
solutions and say they're not physical, Like if you're talking about,
you know, how a ball moves through the air, you
have a parabola. And sometimes there are non physical solutions

(33:41):
to those equations, and you say, oh, those don't make
sense because they required the ball to move through the
ground or something. But he thought, no, this is real.
It's kind of like if you said that the number
of cookies that I have times a number of cookies
you have equals nine. You wouldn't say we both both
have minus three cookies. That wouldn't that want to be
a serious solution, because let's face it, we always have cookies. Yeah,

(34:05):
you impose a physical requirement there at least zero cookies. Right,
there's no such thing as a negative cookie. And but
Dirac was like, you know what, what if negative you
can count it as a negative. If I eat your cookies,
then maybe you have negative cookies. I don't know. I
would have a very negative reaction. Sure. I think there's
probably a whole course in philosophy on theory of negative cookies,

(34:27):
the ethical ramifications of less than zero cookies. Yeah, anti
ethics or anti pastry. But he predicted it. He was balls,
and he said, I believe in myself, I believe in
my equation. I think this thing is real. So he
predicted his way before iPhones or the internet. Yeah, he
couldn't have just googled for it or asked Siri if

(34:49):
this is real. He made a prediction. And he's sort
of famous for being, you know, a bit of an
odd guy. You know, he probably fit in well on
the Big Bang theory. It had a lot of self confidence,
but maybe not a lot of social skills. He made
the claim that these equations work for an anti electron,
so therefore there must be an anti electron. Is that is? That?

(35:10):
Was that his big leap there? That was his big leap.
He says, I've discovered this equation, and the equation is
fundamental to the universe and it describes something happening that
we haven't seen. So I think it's happens right, even
though we haven't we haven't seen it because we haven't
looked for it. This equation allows for it to happen.
So let's go see if it does happen. Was that
a shift in physics as well? You know, people thinking

(35:31):
that well, if the if the math predicts it, then
it must be real. You know, like that's a big
leap to think about that. It's a big leap. It
takes a lot of ego but it was the first
time a particle had been predicted. Yeah. Before that, every
particle discovered had been discovered first and then explained. It's like, oh,
look who we found How does that make sense? Let's

(35:52):
try to stitch together a theory that that accommodates it.
It's like in baseball, it's like calling your shot run
than just hitting a home run. You're like, I'm gonna
hit a home run and it's the land right over there. Well,
I guess he had a history. Maybe he had up
to that point, there was a history where they had
discovered particles and then they found out the math fits it.
So then this, in this case, the math fitted and

(36:13):
so he probably thought, well then it must exist. Yeah,
And it didn't take long for him to be proved. Right.
He was a babe ruth of physics. Yeah, and he
gets better. So it was just a few years later
a guy at cal Tech named Carl Anderson. He actually
found the first positron, and like we were talking about,
he found it in cosmic rays. He just saw one
flying through the air. And what made him think it

(36:35):
was a positron or an anti electron? Was he looking
for it? Or I guess maybe his setup could only
work for an anti electron. No, he was looking just
to study cosmic rays, which were fairly new discovery at
the time. The whole idea that there were these particles
being rained on us from the upper atmosphere was sort
of new, and he was using a pretty cool device.
At the time, the first cosmic rays were discovered basically

(36:57):
by huge cubic blocks of film that they had to
slice up and analyze later. But he wanted some real time.
He wanted to see these things in real time, so
he used this thing called the cloud chamber, which is
basically a box of glass that you can see into
and then you fill it with air which is supersaturated
with water, and when a particle goes through it that
has a charge, it will cause droplets along its path,

(37:19):
and so you see are these like little drops of
water appear as a particle flies through it. You can
actually build the cloud chamber in your garage. Yeah. It
creates like a trail of bubbles as it goes through.
Not bubbles, there's there's something else called the bubble chamber.
This creates a trail of water droplets and you can
see them, and they have them in a lot of
science museums you can see like muans flying through them,

(37:42):
and so he had seen muans and people have seen
electrons and stuff like this. But then he put it
in a magnetic field, and the magnetic field bends the
path of this particle, and the magnetic field will bend
a positive particle differently than it bends a negative particle
cool and so that this was just a few years
after direct So he did he know about directs prediction

(38:03):
or did he discover it kind of independently. Now, he
definitely knew about directs prediction. It was an idea that
was out there, so it helped him sort of interpret
his data. And what he saw was, of course, a
bunch of electrons. Electrons are much more common in the
atmosphere than positrons. But then he saw this one track,
this track that curved the wrong way, and he said,
what's that? You know? And he could tell the mass

(38:26):
of the particle by how much it curved, and you
could tell the charge of it by the direction of
its curve. So he knew, for example, it wasn't a proton,
because the proton is much heavier and would have curved less.
So curved just like an electron except the other way,
except the direction. Yes, And this is amazing to me
because these days, to discover something, you don't just need

(38:48):
one example. You can't be like, hey, look here's the
Higgs boson. We found it, and here's the picture of it.
You know, um, we need like five examples or something
to show statistically that it really exists. Really, he claimed
his discovery with and equals one data points and equals one.
It was so conclusive. Nothing we knew of could make

(39:08):
that data. He didn't even wait to get another one. No,
he didn't even wait to get another one. And you
can see like that is famous data. You can google
for it and see like his original data that proved
the discovery of the positive. Sure he didn't he didn't
get at least two. He didn't wait a little bit
and got another one. Maybe he got some backup data,
but you know that's all he needed. That that convinced everybody.

(39:30):
I'm still convinced by one image. Yeah, and um, and
so he discovered that was ninety two. And then the
next year Dirac wins the Nobel Prize for predicting antimatter.
Did Carl and Anderson also get it? Or just the
just the rack in nineteen thirty three, but then Anderson
wanted three years later sort of in a combined Nobel

(39:53):
Prize for cosmic rade discoveries. But my favorite bit of
this story is that Dirac, you know, he was a
heavy guy, and he made of this bold prediction and
then it actually had come true. So then you know
he like called his shot at like babe Ruth. So
then in his acceptance speech where he's like, you know,
at the Nobel Prize ceremony getting the Nobel Prize from
the King of Sweden, in that speech he predicts another particle.

(40:15):
He like doubles down. He's like, I predict a million
dollars in my bank account tomorrow. He predicted the anti proton.
He was like, well, if the electron has an anti particle,
why not the proton? So he predicted it. Oh wow.
And then when he got the Nobel price for that one,

(40:36):
did he also make another prediction in the next speech, like,
how when did you stop? It's still going on? Actually,
I see he's still making predictions. He's like, and the
next election will be won by Hey, doubling down works
for you, right, you just keep doubling down. And the
exponentially you get more and more Nobel prizes. Yeah, yeah,

(40:58):
alright cool. So that's how the antimatter, the first antimatter
particle was discovered, and since then we've we've seen antimatter
particles all over the place and for all kinds of
particles to write, that's right. And these days in particle
collisions we can very easily make anti electrons, which are positrons,
and anti muons, and we've seen antiquarks and all sorts

(41:21):
of crazy stuff. There are some antiparticles we haven't seen yet.
Oh really, they're still hiding or there's still we just
haven't bothered. Well, no, there's some some that are still hiding.
For example, anti neutrinos. Like we know neutrinos are a thing.
What we don't know is if there are anti neutrinos.
I mean we talk about it, but we don't really
know if anti neutrinos are just the same thing as

(41:44):
neutrinos because they have no electric charge. Yeah, how can
you be anti nothing? Yeah? Well, for example, the photon
is its own antiparticle, or you could say it doesn't
have an antiparticle. So we don't know if neutrinos are
in that category of particles that don't would have antiparticles,
or if they're in the category of particles like electrons
and do have antiparticles, like asking who who is the

(42:08):
anti version of Switzerland and sucerand is neutral? So nobody
and everybody precisely. So people are trying to figure out
do neutrinos have antiparticles or are they just themselves? Um,
all sorts of stuff, And then people are doing more
and more experiments to make antimatter and try to study
its chemical properties. We'd love to see, like more than

(42:28):
just anti hydrogen. We'd love to see you know, anti
water and all sorts of crazy stuff. But I guess
the point is that it does exist, and that it
is something that was predicted by the physics, by the
equations first, and then we went out and found it,
and now there's in controvertible proof that it does exist,

(42:48):
that antimatter can exist, does exist, even if we don't
know exactly where it is in the universe. That's right.
Even though it's been featured in the Dan Brown novel,
it is really out there, and it's a triumph in
the theoretical physics to sort of notice these patterns in
the universe and assume that the universe might follow those patterns,
right to say, we think the universe makes sense, and

(43:10):
if we can figure out the rules that describe it,
then maybe we can use that to predict things in
the universe we've never even seen. Right, what a crazy
step forward. Yep, it's not a conspiracy theory. It's a
conspiracy fact. We have a picture of it from that
says that it's true, so it must be true. It's

(43:31):
out there, it's in you, it's in me, it's in
jogees bananas, So get used to it, folks. All right, Well,
we hope you enjoyed that and got to learn a
little bit more about the anti universe out there, the
antihistory of physics, or the physics of antihistory, or the
history of anti physics. Well, you've definitely convinced me. Daniel
am definitely pro anti matter. Now, thanks everyone for tuning in.

(44:02):
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(44:24):
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