December 5, 2019 • 42 mins
Scientists recently discovered a supposed fifth force of the universe. Is it real and what does it mean for physics?
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Speaker 1 (00:08):
Hey, Daniel, if I wanted to win a Nobel Prize
super quickly, like right now, what would I have to do?
Are you in some sort of hurry You're applying for
a new job or something. I might be applying for
some new cartooning jobs and I figured that might help.
Or you looking apply for my job? Is that what's
going on here? Anyway? If you wanted to win a
Nobel Prize super quickly, you'd have to discover something new,
(00:31):
like a new particle. You know. That sounds good, but
actually we kind of see new particles all the time.
They're just like different versions of the particles we already knew.
So I'm not sure that would cut it. So what
would I have to discover? Then? Maybe like a new
force of nature? What if I discover the force like
in Star Wars. Well, it depends on where you're applying
for your job, if you want to discover the dark
(00:52):
side or not. Hi am Jorge. I'm a cartoonist and
the creator of PhD comics. Hi I'm Daniel. I'm a
(01:15):
particle physicist, though I've never discovered a particle, nor have
I ever won the Nobel Prize yet yet. Daniel career
over yet. That's right, You've got you still got a
lot of podcasts to record here. That's right. Every podcast
I do decreases my chances of discovering a new particle
or finding or learning a Nobel Prize. And sorry, but
(01:38):
remember we are discovering new friends through this podcast every time,
and we're helping everybody else discover the amazing, crazy, wonderful
truths about our universe. That's right, So welcome to our podcast,
Daniel and Jorge Explain the Universe, a production of My
Heart Radio in which we take the things that actual
working scientists are doing and revealing and learning about our
(02:00):
universe and explain them to you in a way that
you can actually understand and maybe even makes you chuckle. Yeah.
And we often try to talk about what's out in
the news recently, you know, the latest discoveries, the latest
headlines that are catching people's attentions out there about exciting
new things that scientists and physicists and Becausemolo Juice have found. Yeah,
(02:21):
And something I take as a real vote of confidence
in our ability to explain things is when something appears
in the news about science and a bunch of listeners
right in and say, hun, can you explain this to us?
And that's just what happened this weekend. I got a
torrent of emails from listeners asking us to explain something
exciting that they saw in the Science News. Do you
(02:41):
think people had options here? Daniel? Like, I could ask
all these different physicists, but I'll uh, I know Daniel,
so I'll ask him instead. Well, Daniel actually writes back,
So maybe that's why they saw or maybe they just
blasted everybody. And you know, I just thought we were
special and we don't charge your fee. That's the best part.
That's right. We do download malware into people's laptops when
(03:03):
the email us. But wait, I'm not supposed to say
that online. Yeah, welcome to Daniel and Jorges bought net
about the universe. Try we do it to Jennifer listener numbers. No,
there was an exciting piece of news over the weekend,
(03:23):
and dating back a couple of years, has been a
trend here and some exciting results dribbling in about a
potentially enormous discovery. Yeah. I saw that this weekend and
I was very curious it was. It was in the
front page of CNN, and my favorite part about that
was that it showed two scientists and lap codes doing
something next to really exciting machines. So I thought, wow,
(03:44):
that's that must be science. It's got to be science
because they're wearing lab coats. Exactly every time I'm about
to get a really good idea, I rushed over to
put on my labat to make sure it's extra science,
just in case someone takes a picture of you. Nobody's
ready ever going to take a picture of me in zience.
But let's not keep our listeners in the dark anymore.
Let's tell them what these article is about. Yeah. So
(04:05):
over the weekend there was there was some big headlines
about a new discovery that was done I think in
Europe that might potentially kind of up in our understanding
of the universe. That's right. The headline of the article
has to do with finding a fifth force of nature. Yeah,
which is maybe more exciting than finding that fifth Beatle.
I here, Well, it depends. If the fifth Beatle gets
(04:29):
to share of all that money, you could be a
much bigger deal. They can they can buy a new
force that money. Yeah. And you know, sometimes you'll see
something online it's like, wow, that sounds like an amazing discovery,
But you don't know is this just the science journalist
drumming it up for clicks, or is this actually a
real turning point in the history of science. And a
(04:50):
lot of times you'll read that and then it'll sort
of fade and you never hear about it again, and
you wonder like, huh, was that actually a thing? Yeah,
it's hard to tell the difference. And so today on
the podcast will be asking the question is there a
fifth force of nature? What's the right context here, Daniel
(05:11):
that makes it epic? Is it force of nature? A
new force of nature or a new force of the
universe or reality? Or what are we talking about? Yeah,
I think the common phrase is a force of nature.
But you know that also like makes you think of
like a hurricane, or clauses and legal documents that let you,
you know, get out of things, acts of God, but
(05:32):
or or just a really motivated person. They're like, Wow,
it's a real force of nature. Somebody must have discovered
her while wearing a lab coat. Yeah in Hungary. No,
for me, it has to do with these sort of
fundamental forces I guess of the universe. You know, to me,
there's not really a difference between nature, reality and the universe.
(05:55):
These things are sort of interchangeable unless we're talking about
the Marvel Comics universe or the d See universe or
the Star Wars universe or other fictional universes. But for
the real universe, what we're trying to do is understand
how it works and understand how many forces there are.
And so that was a It's a big deal. And
do you think it got a lot of play in
the media that people can afforded it a lot and
(06:16):
ask questions about it? Yeah? I think so. Our listeners
certainly seem to have picked up on it, and there
are a lot of interest Is this real? What does
it mean? Can you help us break it down? Um?
And so to sort of get a broader context or
whether this had penetrated into, you know, the community in general,
I did something a little bit different with our street interviews.
(06:37):
Rather than walking around campus at you see Irvine, I
just went to a random coffee shop in Orange County
and I asked random folks if they had heard about
this discovery and if even if they knew about the
original four forces of nature. So these might be a
little bit more caffeinated than the usual answers a little
bit more caffeinated, a little bit less ramen noodle infused.
(06:57):
Perhaps I academic less academic exactly, you know, a broader
section of the Orange County public. So think about it
for a second dose of you listening out there. If
someone asked you at a coffee shop, what is the
fifth force? Think about what you would answer. Here's what
people had to say. No, never, I've never. I didn't
(07:17):
even know what better? Okay, no, what is it? No? No,
I'm not hunting through. I saw an article if I
just saw the headache? No, no, well, I don't know
what the four forces about it? No, don't you do that?
The song earth wind and fire like wind, fire, earth
(07:39):
like earthquakes and then also water. All right, I guess
maybe they hadn't checked this front page of the CNN
yet a lot of people, it seems, no, only one
person had even heard of the article, and very few
people could even really comment intelligently on the four forces
of nature. I got a lot of sort of ancient
Greek ideas, like earth in the Fire. I thought they
(08:02):
were talking about the rock group Earth Wind and Fire.
They really were a force of nature. What will be
the fifth force? In that case, Earth when fire, Sun politics,
rama noodles. Yeah, so I'm not sure that everybody else
out there understands the ramifications of this potentially mind bending,
earth shattering, universe upturning discovery. So maybe we should really
(08:25):
start at the beginning. Yeah, I guess it wasn't like
we interrupt this broadcast for an important physics announcement, have
landed on the Moon and discovery the fifth Force. Yeah,
it wasn't like a stop the press this kind of thing. Yeah,
we didn't have President Trump commenting on this discovery yet
looking up at the Sun to see if that's were
(08:45):
the fourth the fifth force was no comment, but that
was the headline. The headline was scientists discover a new
force of nature, right like, um, like, if you didn't
know there were forces, they just found a new one. Yeah, precisely,
and so um that sounds like a big deal. But
(09:05):
I thought, since people out there might not be terribly
familiar with the forces that are out there and what
means to be a force and what we think of
from a physics point of view as a force, I
thought maybe we should start by talking about what the
four forces actually are. Yeah, the ones that we do
know about, right, the fat four of fundamental forces. That's right,
(09:26):
all these physics you'll be shocked to discover that there
is not consensus agreement among physicists about how many forces
we've discovered. Oh jeez, some say three, some say four,
some say five. There's controversy about how many there are now,
but they but now they've discovered another one. This controversy
about that too. All right, well, let's get into it, Daniel.
(09:47):
Let's talk about the forces we do know about. Um, so,
what are the four or three fundamental forces in the universe?
So off the bat, we think about the four fundamental
forces as gravity, the strong nuclear force, the weak nuclear force,
and electromagnetism. If you have to ask me, or you're
costed me on the street and ask me what the
(10:08):
four forces where, that's what I would say. You wouldn't
say there are only three. Well, you know, from a
particle physics point of view, we've done a pretty good
job of showing that electromagnetism and the weak force are
really one and the same. They're just two sides of
the same coin. In fact, in particle physics we refer
to them as the electroweak force, so that from that
(10:29):
point of view, you have three forces gravity, the strong force,
and the electroweak force. But traditionally the weak force is
kind of its own thing, and it's kind of is
because it has its own like particles that interacts with, right.
It doesn't use the photon like the electromagnetism forced us. Right.
But you know, if you want to talk traditionally, like historically,
(10:50):
electromagnetism is a new thing. They used to be electricity
and magnetism they were identified initially is totally separate phenomena
and then later understood to be too sides of the
same coin and merge into one that we now call electromagnetism.
So you know, years and years ago you might have
said five fundamental forces, that we emerged that down into four.
Now we've merged that down into three. So I think
(11:12):
three is actually the best description of you know, what
we currently understand. But that's not a widely held opinion.
Is this, like the Greeks thought that maybe there are
only three forces, like like women, fire were actually the same. Yeah,
except that we actually have more data than the Greeks.
Did we conclude this pretty conclusively and mathematically. Yeah. Okay,
(11:32):
so there are three or and or four. We'll say
there are three point five forces about that the difference.
This is not the kind of thing you want to
compromise on. This non negotiation. I'll give you three point
seven five plus you get the house on weekends. Maybe
you should, and maybe you would have more headlines that way. No,
(11:53):
And to remind people, electromagnetism is a force you're familiar with.
It's responsible for electricity from magnetism um and also for
chemical bonds. Is basically what holds your body together. It's
what makes the wall seems solid, you know. It's it's
responsible for most of the forces you actually feel. And
the weak force is not one you come and commonly feel,
(12:15):
but it is sort of related to the electromagnetic force. Yeah,
it's very closely related to electromagnetism. The particles that contribute
to the weak force are the W and the Z,
and you can think of them sort of like heavy photons.
Because they're heavy, it makes the force very weak and
it makes a very short distance scale. And so this
one really only comes into play for things like neutrinos
(12:36):
and radioactive decay. And I was actually talking to a
particle theorist this morning who said he didn't even consider
the weak force a force because you can't really feel it,
not even weakly. Not even weakly. Yeah, um, but I
consider it a force. Is a it's one of the
fundamental forces of nature, part of it because but it
gets lumped in with electromagnetism because like the math and
(12:59):
the the photon and the bosons, they are all sort
of act the same way, or they all fit into
the same mathematical box. Is that kind of why you
think they're all the same. Yeah, it just makes much
more sense mathematically if you put them all together in
the same box, and you can show that you start
from a certain set of particles and they get rotated
sort of by the Higgs boson and turn into the
(13:19):
particles we have. We should do a whole interesting podcast
episode about electroweak symmetry breaking. But just briefly, you know,
we have these forces, electromagnetism and the weak force, and
they're responsible for some of these physical effects. But then
of course there's also the strong force and gravity, right,
and so the strong force is the one that holds
the nucleus together, right, Like, without that one, all of
(13:40):
our nuclear which is fall apart. That's right. Remember, the
nuclei are protons and neutrons, and protons are positively charged
and so they repel each other, and the neutrons are neutral,
so they can't do anything to really help. So from
an electromagnetic point of view, the nucleus shouldn't even hang together.
We did a whole podcast episode about how the strong
nuclear force holds the nucleus to other So without the
(14:01):
strong force, we wouldn't have nucleari, we wouldn't have fusion,
we wouldn't have stars. It's pretty important. And gravity, that's
the that's the heavy one, right. Yeah, gravity is the
weakest force actually by all of these things. But it's
something you're familiar with because there are big sources of
gravity nearby, and so gravity will pull together anything that
has mass. You, your friend, your neighbor. You guys actually
(14:22):
feel gravity pulling on each other. Um, you just can't
really sense it because it's so small. Most of the
gravity you feel is with respect to the Earth or
if you're the oceans, with respect to the moon. Okay,
so those are the four or three and a half
forces um electromagnetism, weak force, strong first gravity, And that's
what we've known for a long time, right, I mean
at least maybe years is what we have known there
(14:47):
to be in nature. Like, that's it. You can't two
things can't pull or push on each other any other way.
These are the four ways that they can do it. Yeah,
and it's important to understand that these are descriptive. They're
just a description of all the stuff we've seen happen.
It's not like they come from some deep principle of
nature where we've derived a rule that there have to
be four forces or there can't be anymore. You know,
(15:08):
you could see tomorrow some new physical effect that can't
be explained by anything else, and that might be a
discovery of a new force of nature. It's just that
so far these forces have been able to describe everything
we've seen. But again, there's no theoretical limit. There could
be like forces and the other nineties are just super
duper duper feeble. We can't even sense them. Oh, I see,
(15:30):
up until Saturday, there was no indication in any of
the up until you went into that Starbucks to ask
people questions. Uh, there's no indication from any experiments that
humans have ever done that there was anything else going
on in the universe. Basically right like that, we hadn't
seen anything. They couldn't be explained by these four fundamental
(15:53):
forces precisely. And that's the way we like to do science. Right.
You see something new and weird, first thing you do
is say, can I explain it with things we know?
Because if you can, and that's the most likely explanation,
just a comes razor. And then you know, if you can't,
then you consider, well, maybe there's something new. I have
to add, something new to my theory, a new particle,
a new force, and new something to explain this new
(16:13):
phenomenon that nothing else I know can't explain. And you
guys felt pretty confident that there were only these four,
because you mean, you've done so many experiments over the
last seventy years, you know, smashing particles over and over
and over and over, that it didn't seem maybe likely
that there were more forces, right, I would have guessed
actually that there were. You know, if I had to guess,
(16:35):
gun in my head, are there more forces? I would
have guessed yes, And that doesn't happen. Hold hold the
gun to your head, Danniel. Somebody in a lab code
I'm sure Rappid from in the dramatic movie right now
my life, you know where physics, And the reason is
(16:56):
that there's a lot going on in the universe that
we know that we don't understand. End um. You know,
we wrote this book all about all the things we
don't know about the universe, and one of them is
that there's dark matter out there. And if there's dark matter,
that means it's a new particle, and a new particle
probably has a new kind of force, because we know
that dark matter doesn't interact with normal matter in any
way that we're aware of other than gravity. But we
(17:18):
think that dark matter probably does interact with normal matter
in some way in order to account for how much
we see it in the early universe. So I would
have guessed that there's a new force out there, like
a dark photon particle that mediates some new dark force.
But we don't have any actual evidence for it's just
a suspicion. Oh, I see all the experiments you've done
pointed to these four forces. But there are still things
(17:40):
out there in the universe we don't understand. Yeah, And
as always, there are patterns and the things we do
understand that suggests something is missing. To say, you know,
This would be a lot simpler if you found this
new particle. So you know, until Saturday, we didn't have
any evidence for that. All right, let's get into this
new discovery and what the news article was all about
and whether it did revolutionize our understanding of physics. But first,
(18:04):
let's take a quick break. Al Right, So what was
the actual article about that came out this weekend that
said that they found a new force of the universe.
(18:27):
What did they actually discover? Yeah, so the article was
misleading in several ways. You won't meet surprised to learn, um.
And the first thing is that this last weekend wasn't
really the most important moment. There's been a series of
papers from the same group in Hungary announcing discoveries for
the last few years, so they've been teasing this. No,
(18:49):
they've been trying to replicate their experiments. So maybe the
most important result came out in two thousand and sixteen
when they first saw evidence for what might be a
new particle, and this paper from recently just sort of
confirmed it in a different system. So let's talk about
what happened in two thousand sixteen, because I think that's
really the most important result. Okay, let's go back in time.
(19:10):
So wh then, what was the actual experiment and in
who who were these scientists and what did they actually discover. Yes,
so it's a group in Hungary and their experiment is
called the atom key Experiment a t O m k I.
The short version of the story is that they see
some things in their detector that they think are consistent
(19:31):
with a new particle, meaning something that they had never
seen before. Yeah, and something that, as we were talking
about before, they cannot explain using the fundamental forces and
particles that we know about. So that sounds exciting. It is,
And they've been doing it since two thousand sixteen, like
they've been talking about this for a while. Yeah, In fact,
they've been doing this kind of physics for quite a while,
(19:53):
and but this particular experiment is interesting. What they do
is they take a proton and they shoot at a
lithium nucleus and then it turns into burrillium because that's
one more atomic number up. So the nucleus sort of
absorbs the proton, but it's not just brilliant, it's like
excited burrillium. It's like has extra energy, so it's like
wiggling and dancing should we picture a dance that the
billium is doing? Which of the Fortnite dances is it doing?
(20:16):
You're the cartoon is you're the visual person. So I
want to see a doodle of dancing Burrellium. When we're done,
it's doing the Charleston. Let's go with that. And just
like you know how electrons can get excited up from
their ground state and then jump down a state. When
you jump down the state, you give off energy. And
so what they what we expect to happen is this
burrillium jumps down back into the ground state and gives
(20:38):
off energy in terms of a photon. Oh I see,
So the proton not just transforms it into a new element,
It transport forms it and gives it kind of extra
surplus energy. Yea. Then it has to get rid of yeah,
because the proton that comes in has a bunch of energy.
It's not just at rest proton just sort of hanging
out comes zooming in with a lot of energy. And
(21:00):
then the brillium nucleus which is then formed, has this
extra energy. It wants to get rid of it. And
so what you expect is for it to shoot off
a photon and then that photon would turn into a
pair of particles, an electron and a positron, and you
can measure the energy of that photon by finding the
electron oppositron and sort of adding them back up. Why
doesn't the photon just keep going as a photon, as
(21:21):
a little bit of light. Why does it have to
turn into an electron and a anti electron? Yeah, they can.
Photons like this can fly across the universe and just
go forever. But these guys have a special trick for
measuring it. In the way they measure the energy the
photon essentially is to induce it to turning into an
electron and an anti electron, so they can it helps
(21:42):
them measure the energy. How do you induce a photon
to not be a photon? Well, every time a photon
goes through matter, it interacts with the all the electromagnetic
fields inside that matter, and that tends to make it
pair produced. That we call it turning from a photon
into a pair of particles. You're gonna like slam it
against something, yeah, And the key thing is that when
you do that, you measure the energy of it, and
(22:04):
you can measure the mass of that particle and photons,
of course, don't have any mass. So you expect that
you get this electron and this positron. You add them
back up to reconstruct what the photon was like, and
you calculate what this mass was. You should get zero.
But what they see is a bunch of events where
it doesn't add up to zero. It adds up to
a different number. It adds up to a blob all
around the same number, around seventeen mega electron volts. So
(22:28):
where did this mass come from? Wit um? So photon
doesn't have mass, so you expected to split off into
an electron and an anti electron. You're saying that that
has to add up to zero. The mass of that
pair has to add up to zero. Yeah, But sometimes
they see something that they can't explain, which is the
(22:49):
mass of that pair adds up to something which is
not zero, which means that the particle that carried that
energy didn't have zero mass, It had non zero mass.
And so essentially what they think they've seen is like
another version of the photon, a different particle that does
have mass. Oh, they think that the photon they're seeing
(23:10):
is not a photon precisely. They think they call it
the X particle good branding. I was wondering if you'd
like that or not exert for like mysterious. We don't know,
you know, if it actually becomes something real, and I
guess they'll give it a real name. I think that
means that they're doing physics X at the end. So
that's the basic thing is that when they plot this
(23:30):
or the mass of this pair of electron and positrons,
they see a bunch of year zero where you expect
to see photons, but they also see a blob all
clustered together around seventeen mega electron volts. And that's the
kind of thing you would expect to see if there
was a new particle. There's something which wasn't a photon,
but brilliant was emitting this X particle when it went
(23:51):
down to its ground state. Oh like sometimes or usually
gives us a gives off a regular photon, but sometimes
you get a lot measurements of something that doesn't look
like a photon precisely. And that's exactly the kind of
thing you would expect to see if there really was
a new particle there. But it's not like there's something
terribly different going on here. I think maybe That's the
(24:13):
weird part for me is like, like I was following you,
it sounded like things I've heard before, but some of
that you're telling me that, like on irregular atom decaying,
suddenly there there's this weird new kind of particle coming out. Yeah,
that's precisely what they're suggesting. And remember that to be
consistent with everything else we've ever seen, it would have
to be pretty subtle. If this was happening a lot,
(24:35):
or shooting out some really powerful rays, or happening really often,
then we would have noticed. Are already we studied atomic
nuclei great detail. We have a pretty good understanding of
how this works. So for this to evade all other
previous experiments, it have to be pretty subtle. Not something
in particular to the beryllium or the lithium. It's just
(24:56):
something that nobody had that had flown under people's it are.
It's not like these um they were taking like super
exotic matter and doing experiments with experiments with it and
they found something new. It's like they were doing something
pretty what sounds pretty regular run of the mill physics. Yeah,
and what they did last weekend, this new result that
(25:17):
just came out is that they reproduced the same results
using helium. So instead of brillium, they excited helium into
a new state and when they saw a decay, they
found a few of these examples of this X particle
that looked just like in the brillium decays, like helium
and helium balloons have some sort of secret particles in them. Yeah,
(25:38):
but you know, if it's real and it's actually there,
it's just turning into electrons and positrons and you can't
tell the difference. So if this thing is real, and
then it could be happening around us all the time,
but it wouldn't make much difference to your world. I mean,
the world with four forces or five forces doesn't look
very different to you. And what did they say in
the paper? Are they just saying like, hey, we look
(26:00):
better than everybody else and so we found it. Or
are they saying, you know, nobody's looked in this range before,
or are they saying this is an interaction like a
reaction that nobody had studied closely before to see it. Well,
nobody else has ever seen this before. Only this one
group from Hungary has seen this before. Now, other people
(26:21):
have done nuclear physics experiments other people have looked at burrillium,
other people have looked at helium. Nobody's ever seen this before. Now,
when they put out the paper in two thousand and sixteen,
nobody really paid attention. They were like, huh, whatever, that's interesting,
but it's sort of in conflict with other results because
nobody had ever seen this thing before. But then a
group of theorists here you see Irvine, actually, Jonathan Fang
(26:44):
and Tim Tate, they read this paper and they thought,
that's interesting. Can we find a way to explain this
result in terms of a new particle that also doesn't
break all the other results that we've seen. Can we
find a reason why all those other experiments wouldn't have
seen this particle yet they looked at it. And Jonathan's
a friend of ours, right we you're a friend of Jonathan,
(27:04):
and I've met Jonathan and he's been in our videos
that we've made for YouTube before, which is why I
was like, I saw the article and then I saw
his name. I was like, what, I know this guy
because it was his paper that got this group a
lot of attention. They published their paper and nobody really
paid attention. But then Jonathan showed that their result could
be consistent with a new particle and also be consistent
(27:25):
with all the other experiments. Essentially, Jonathan found a way
to explain away all the other results because all the
other experiments have slightly different configurations or use a different
energy range or a different kind of particle a different
kind of detector. So Jonathan found a theory that explained
this new result and also was consistent with everything we've
seen before, and that is what made it exciting. I
(27:45):
feel like that's really gutsy, you know, like if you
read a paper with a crazy idea that probably clearly
sounds like they just made a mistake to be like Nope,
I'm gonna sit down and I'm gonna double down and
find a theory that might explain weird circumstance. Yeah. I
think it actually sort of went the opposite direction. They
were like, well, here's a crazy result. It's ruled out
(28:07):
by all these other experiments, right, let's do the calculation,
let's estimate, let's see if these other experiments actually are
in conflict with this one, or if we can find
a way to wiggle this one out. I think it
started as an exercise and then they realized ham there
really is an opening there. There's a way that you
can explain this new result that doesn't conflict with the
other ones. And that's when they got excited. Do you
(28:27):
mean it was kind of like Jonathan was sitting on
a Sunday and he's like, I could do the cross
word puzzle today, or I could just you know, pass
some time working out some equations for this experiment. Um.
I don't know. I think it was an exercise at
the time. He was working with his post doc Flip Tonedo,
who's also a friend of ours on the podcast and
is now a professor e C Riverside, and they were
(28:48):
just sort of working through this as an exercise and
then discovered, hey, maybe this overlooked piece of evidence from
Hungary is actually evidence for a new force of nature.
That was an exciting moment for them. Interesting. If he
hadn't done that, then people might have just ignored this experiment. Yeah, yeah,
I think so. I think it was the attention of
this frankly world class group of theorists and this reasonable
(29:11):
argument for how it might be a big discovery that
pointed the world's scientific attention to this group and Hungary.
All right, well, we'll have to ask Jonathan over a
beer or something, how he got in, how he found
this article and what made him get interested in it.
But yeah, let's talking about the result itself and whether
it's significant and whether it is actually a new force
(29:33):
of nature. But first let's take a quick break, all right, Daniel,
So have they found a new fifth force or I
(29:53):
guess four and a half fource of the universe. I
would say it's way too early to tell. I mean,
first of all, I don't think we can even really
conclusively say that they have seen a new particle. And
then there's the follow up question of if it is
a new particle, is it a new force? Also, so
you you have doubts about or you want to see
more evidence about whether or not even found anything. And
(30:16):
then there's actual deeper questions about whether it actually means
there's a new force. That's right, this result only comes
from one team, this team in Hungary. And before you
really believe that a particle exists, do you want to
see it replicated by an independent team? You want to
see another group that has a different setup and maybe
different potential biases, make the same measurements and see the
(30:37):
same thing. I mean, if it's a real thing in nature,
you should be able to see it in more than
one place. It's like when we discovered cold fusion, that
group in Utah. Other groups immediately went out to see
if they could reproduce it, and nobody could, which is
how we knew that it was bogus. And that doesn't
mean necessarily malfeasance, you know, it doesn't mean that they're
lying to us, But it's a There's a lot of
ways to accidentally bias your result or introduce a mistake,
(31:02):
and that's why we cross check things to science. So
where are we at now? Have people tried to replicate
it or has just nobody tried And so that's why
it's an open question. Like it doesn't sound like a
super difficult experiment, isn't like you don't need billions of
dollars for it. You don't need billions of dollars. You
need some sort of particle accelerator so you can get
these protons up to the right energy, and then you
(31:24):
need a detector that can transform this particle into your
positiron electron pair and measure it precisely. And you also
just need time and interest. And so there are a
few groups out there that are interested in potentially reproducing
this measurement using slightly different equipment, but nobody has done
it yet, and until that happens, I don't think anybody
in science is really going to take this result seriously. Well,
(31:46):
it's kind of a weird incentive, right, because like, if
I'm a physicist, what's my incentive to being the second
guy who confirms the first guys or first girls or
gals experiment? You know what I mean? Like, it's like
it's a weird thing to jump into, you know, because
you want to get all the glory, and if you
disprove it, then you know, you would you probably wouldn't
(32:07):
get munch of glory either. That's an interesting question, and
I think that goes to like who would get the
credit for this kind of discovery, you know? And should
it go to the Hungarian folks? Should it go to
Jonathan and those folks for recognizing the importance of this,
should it go do a new team that verifies it?
Should you split it three ways? I'm not sure. To
me for having a podcast about it, I'm not sure.
(32:29):
And you know, there's also a question of sort of
priorities and credibility you know, everybody out there's a lot
to do in science and a long list of experiments
they'd love to get done, and given infinite funding, sure,
I'd like to see this thing happen, But you know,
is it the most important thing that these other groups
can be doing with their time? And also, does anybody
really believe this result? This Hungarian group has sort of
(32:52):
a I mean there are whispers and hallways and physics
departments about a checkered past from this group, claiming discoveries
which didn't pan out. Oh man, gossip gossip. There is
physics gossip. And you know there's people who have now
retired and I think passed away who used the same
facilities and made a lot of claims about new particles
(33:13):
they thought they discovered, which then sort of went away
and no longer part of this team, of course because
they've passed on. But it sort of lingers. The questions
linger about whether results from this facility can really be trusted.
I'd like to see that TV show Gossip Girl for
for physics. And you know, in the end, the results
speak for themselves, either you believe them or you don't.
And and importantly, nobody has found a flaw in their work.
(33:36):
People have combed through the details and nobody has found
a mistake. And also people have worked really hard to
try to explain the results using just standard physics, using
the four forces we know, and nobody has been able to.
So it's either a very subtle mistake or it's real.
You're kind of saying that it's suspect. But if it's
(33:56):
a hoax, it's a really good hoax. I'm not saying
it's a hoax, right. Hoax implies that these folks are
tricking us. I think they're doing honest work. Oh, I
see right. But if it's a mistake, it's a really
well hidden mistake. If it is a mistake or not, no,
And it's really easy to make subtle mistakes. You know,
these detectors only see a fraction of the events, and
so you have to make some assumptions about the ones
(34:17):
you missed, and it's very easy to introduce biases. We
have lots of examples in particle colliders, for example, where
we see bumps in our data and we think, oh
my gosh, maybe that's a new particle, and it turns
out it came from a complicated series of of influences
from this and that me other which produce a bump
in your data. So it's easy to produce false bumps.
And so what you really just need is a totally
independent cross check. And you would need that for any group, right,
(34:39):
even if this was a very well respected group from Harvard,
you would definitely need independent confirmation before you believed it.
All right, Well, let's get into the details a little bit.
I think we have time and talk about to the
idea that Jonathan proposed, or that this group proposed at
the same time, was that like, maybe this is a
new particle that we're seeing. Maybe this particle has a
(35:01):
new force of nature attached to it. Yeah, and that's
really sort of just interpretation. All we know is if
this particle is real, it decays into an electron and
positron pair, and that means that it has to have
into your spin because the electrons and positrons are spin
half and so they have to add up to either
spin zero or spin one or whatever, but into your spin.
(35:23):
And that's the kind of particle we call a boson.
Bosons have intoed your spin. And so this looks like
it's a boson, that's right. And so the most conservative
thing you could say, is if this is real, it's
a new boson. Is a photon a boson. A photon
is a boson, the W, the z, bluon, all these
particles are boson's. Every boson we know of is associated
(35:43):
with the force. Photon carries electromagnetism, that W and Z
carry the weak force, gluons carry the strong force. If
gravity is a quantum force, it would have a graviton,
which is a boson. So this is there's this association
between bosons and forces. Okay, and you think so you
you sort of know it's a boson because of the spin,
(36:04):
but do you think it might be a new boson
because it weighs differently than all the other bosons you
know about? Precisely? But I think there's some disagreement in
the physics community about whether every new boson has to
be a force. For example, we discovered a new boson
a few years ago, the Higgs boson. Is the Higgs
boson represent a new fundamental force of nature. Some theorists
(36:27):
say yes, Some theorists say no, because the Higgs boson
also doesn't just fall out of requiring what we call
a local gauge symmetry, which is a fancy jargon for
having a certain kind of math. But how do you
know it's not just a like a W boson that
weighs differently, or like a boson W boson that eight
too much for lunch. This is much much lighter, right.
(36:48):
The W boson is about, let me do some math
um four thousand times heavier than this new X particle.
So it has to be a W boson on a
strict diet. It's like intermittent fast W boson. It's a
W boson that's skip lunch. Well, that's a good question.
So you also call that in a different like like
(37:09):
a W boson that ways less would still be a
new boson. W boson that wass less would still be
a new boson. Like we are looking right now for
new versions of the W that have different masses. That
would be a different particle, because the mass of the
particle really shapes its identity. It's part of what we
call a particle. And you know, like finding a heavier
version of the electron, that would be a new particle.
(37:29):
It's who they are, it's who they are um. And
so there's not an agreement about whether every boson really
represents a new force or not. Even if you find
a heavier W Boson, that doesn't mean there's a new force.
It just means you found a heavier W Boson. That's right.
But of course it sounds cooler to discover a new
force than a new particle, and so I think that's
why some people described in the media is like, discovery
(37:51):
of a new force of nature sounds sexier. It it
focus grouped better than discovery of a new particle of nature.
You would get more clicks if you say we found
any force then you say and then if you say
we find a new Boson, that get lunch. That's right,
But it could be It could be that there is
a new fundamental force out there and this boson carries
that force, and that this is the first piece of
(38:12):
evidence for the discovery of this new particle, which is
the clue to the new force, which tells us something about,
you know, the way the universe works. Although I think
you would get a lot of clicks if you wrote
the headline as you won't believe what this boson life
now with its new diet. That's right, But you know
there's also competing forces here because physicists are trying to
(38:32):
discover new forces, we're also trying to get rid of forces.
You know. One of our goals is to describe all
the forces in terms of one mathematical structure, Like we
combined electricity and magnetism into electromagnetism, and then with the
weak force into the electro week. We'd love to find
the grand unified force that encapsulates everything. So on one hand,
we want to find more forces, and then on the
(38:54):
other hand, we want to sort of shoehorn them together
into one framework. It's like when you're trying to clean
up your kid's room and you got everything sort in
the closet, and then the kid comes up and says, look,
I found this toy, and you're like, great, well. It's
sort of like when you're trying to solve the jigsaw puzzle.
First you want to get all the pieces and categorize them,
(39:14):
and then you want to see if they fit together
into one nice picture. But you can't do that if
you don't have all the pieces. And so we desperately
want to figure out are there other pieces out there
that we're missing? Because we know this a lot about
the universe. We haven't understood. When you get a headline
like this, you're both kind of excited but also like
you've grown a little bit, like, oh, that means that
means we're behind. But hey, isn't it exciting that we're behind.
(39:37):
We're always behind. It's not like this a schedule for
discoveries of the universe. We're never gonna understand everything behind
one of my jet packs yesterday, yesterday. You know, we
are always going to be behind. So it's always exciting
to hear about more physics to understand. All right, Well,
it sounds like the answer here is stay tuned. Sounds like, um,
(40:00):
they found something amazing, or maybe they found something but
it's it's not that revolutionary, or maybe they maybe they
didn't find anything. Maybe it's just something that there that
people are overlooking. Yeah, stay tuned for independent confirmation. Until
we get that, you really should just put a pin
in it and think about it as a cool result
that maybe we'll understand one day. Right, until then, we
(40:22):
still only have three and a half fundamental forces three.
That's my final offer. Let's get three point six and
then weekend end this podcast Daniel done, especially after we
account for Lawyer's fees on the forces. All right, Well,
hopefully that answered people's curiosity and questions about this headline
that came over the weekend. Yeah, so thanks for sending
(40:44):
in your questions. If you see something in the Science
News that you don't understand, please send it to us
at Questions at Daniel and Jorge dot com. We'll break
it down for you. And remember Daniel answers Twitter and email,
but he doesn't answer Instagram, Instill what instead? You know
what the kids are using? But I think you do
answer TikTok? Do you do TikTok? I don't know what
(41:08):
that is, but I definitely do it. Loll the kids
are doing it. I mean I'll put a lab coat
on and make one of those ticker talkers. There you go.
Well all right, well, we hope you enjoyed that and
see you next time. Thanks for tuning in, and thanks
for lending us your brain for fifty minutes. Before you
(41:37):
still have a question after listening to all these explanations,
please drop us a line. We'd love to hear from you.
You can find us on Facebook, Twitter, and Instagram at
Daniel and Jorge that's one word, or email us at
Feedback at Daniel and Jorge dot com. Thanks for listening
and remember that Daniel and Jorge Explain the Universe is
a production of I Heart Radio. For more podcast from
(42:00):
my heart Radio, visit the i heart Radio a Apple Podcasts,
or wherever you listen to your favorite shows. H
Hey, Daniel, if I wanted to win a Nobel Prize
super quickly, like right now, what would I have to do?
Are you in some sort of hurry You're applying for
a new job or something. I might be applying for
some new cartooning jobs and I figured that might help.
Or you looking apply for my job? Is that what's
going on here? Anyway? If you wanted to win a
Nobel Prize super quickly, you'd have to discover something new,
(00:31):
like a new particle. You know. That sounds good, but
actually we kind of see new particles all the time.
They're just like different versions of the particles we already knew.
So I'm not sure that would cut it. So what
would I have to discover? Then? Maybe like a new
force of nature? What if I discover the force like
in Star Wars. Well, it depends on where you're applying
for your job, if you want to discover the dark
(00:52):
side or not. Hi am Jorge. I'm a cartoonist and
the creator of PhD comics. Hi I'm Daniel. I'm a
(01:15):
particle physicist, though I've never discovered a particle, nor have
I ever won the Nobel Prize yet yet. Daniel career
over yet. That's right, You've got you still got a
lot of podcasts to record here. That's right. Every podcast
I do decreases my chances of discovering a new particle
or finding or learning a Nobel Prize. And sorry, but
(01:38):
remember we are discovering new friends through this podcast every time,
and we're helping everybody else discover the amazing, crazy, wonderful
truths about our universe. That's right, So welcome to our podcast,
Daniel and Jorge Explain the Universe, a production of My
Heart Radio in which we take the things that actual
working scientists are doing and revealing and learning about our
(02:00):
universe and explain them to you in a way that
you can actually understand and maybe even makes you chuckle. Yeah.
And we often try to talk about what's out in
the news recently, you know, the latest discoveries, the latest
headlines that are catching people's attentions out there about exciting
new things that scientists and physicists and Becausemolo Juice have found. Yeah,
(02:21):
And something I take as a real vote of confidence
in our ability to explain things is when something appears
in the news about science and a bunch of listeners
right in and say, hun, can you explain this to us?
And that's just what happened this weekend. I got a
torrent of emails from listeners asking us to explain something
exciting that they saw in the Science News. Do you
(02:41):
think people had options here? Daniel? Like, I could ask
all these different physicists, but I'll uh, I know Daniel,
so I'll ask him instead. Well, Daniel actually writes back,
So maybe that's why they saw or maybe they just
blasted everybody. And you know, I just thought we were
special and we don't charge your fee. That's the best part.
That's right. We do download malware into people's laptops when
(03:03):
the email us. But wait, I'm not supposed to say
that online. Yeah, welcome to Daniel and Jorges bought net
about the universe. Try we do it to Jennifer listener numbers. No,
there was an exciting piece of news over the weekend,
(03:23):
and dating back a couple of years, has been a
trend here and some exciting results dribbling in about a
potentially enormous discovery. Yeah. I saw that this weekend and
I was very curious it was. It was in the
front page of CNN, and my favorite part about that
was that it showed two scientists and lap codes doing
something next to really exciting machines. So I thought, wow,
(03:44):
that's that must be science. It's got to be science
because they're wearing lab coats. Exactly every time I'm about
to get a really good idea, I rushed over to
put on my labat to make sure it's extra science,
just in case someone takes a picture of you. Nobody's
ready ever going to take a picture of me in zience.
But let's not keep our listeners in the dark anymore.
Let's tell them what these article is about. Yeah. So
(04:05):
over the weekend there was there was some big headlines
about a new discovery that was done I think in
Europe that might potentially kind of up in our understanding
of the universe. That's right. The headline of the article
has to do with finding a fifth force of nature. Yeah,
which is maybe more exciting than finding that fifth Beatle.
I here, Well, it depends. If the fifth Beatle gets
(04:29):
to share of all that money, you could be a
much bigger deal. They can they can buy a new
force that money. Yeah. And you know, sometimes you'll see
something online it's like, wow, that sounds like an amazing discovery,
But you don't know is this just the science journalist
drumming it up for clicks, or is this actually a
real turning point in the history of science. And a
(04:50):
lot of times you'll read that and then it'll sort
of fade and you never hear about it again, and
you wonder like, huh, was that actually a thing? Yeah,
it's hard to tell the difference. And so today on
the podcast will be asking the question is there a
fifth force of nature? What's the right context here, Daniel
(05:11):
that makes it epic? Is it force of nature? A
new force of nature or a new force of the
universe or reality? Or what are we talking about? Yeah,
I think the common phrase is a force of nature.
But you know that also like makes you think of
like a hurricane, or clauses and legal documents that let you,
you know, get out of things, acts of God, but
(05:32):
or or just a really motivated person. They're like, Wow,
it's a real force of nature. Somebody must have discovered
her while wearing a lab coat. Yeah in Hungary. No,
for me, it has to do with these sort of
fundamental forces I guess of the universe. You know, to me,
there's not really a difference between nature, reality and the universe.
(05:55):
These things are sort of interchangeable unless we're talking about
the Marvel Comics universe or the d See universe or
the Star Wars universe or other fictional universes. But for
the real universe, what we're trying to do is understand
how it works and understand how many forces there are.
And so that was a It's a big deal. And
do you think it got a lot of play in
the media that people can afforded it a lot and
(06:16):
ask questions about it? Yeah? I think so. Our listeners
certainly seem to have picked up on it, and there
are a lot of interest Is this real? What does
it mean? Can you help us break it down? Um?
And so to sort of get a broader context or
whether this had penetrated into, you know, the community in general,
I did something a little bit different with our street interviews.
(06:37):
Rather than walking around campus at you see Irvine, I
just went to a random coffee shop in Orange County
and I asked random folks if they had heard about
this discovery and if even if they knew about the
original four forces of nature. So these might be a
little bit more caffeinated than the usual answers a little
bit more caffeinated, a little bit less ramen noodle infused.
(06:57):
Perhaps I academic less academic exactly, you know, a broader
section of the Orange County public. So think about it
for a second dose of you listening out there. If
someone asked you at a coffee shop, what is the
fifth force? Think about what you would answer. Here's what
people had to say. No, never, I've never. I didn't
(07:17):
even know what better? Okay, no, what is it? No? No,
I'm not hunting through. I saw an article if I
just saw the headache? No, no, well, I don't know
what the four forces about it? No, don't you do that?
The song earth wind and fire like wind, fire, earth
(07:39):
like earthquakes and then also water. All right, I guess
maybe they hadn't checked this front page of the CNN
yet a lot of people, it seems, no, only one
person had even heard of the article, and very few
people could even really comment intelligently on the four forces
of nature. I got a lot of sort of ancient
Greek ideas, like earth in the Fire. I thought they
(08:02):
were talking about the rock group Earth Wind and Fire.
They really were a force of nature. What will be
the fifth force? In that case, Earth when fire, Sun politics,
rama noodles. Yeah, so I'm not sure that everybody else
out there understands the ramifications of this potentially mind bending,
earth shattering, universe upturning discovery. So maybe we should really
(08:25):
start at the beginning. Yeah, I guess it wasn't like
we interrupt this broadcast for an important physics announcement, have
landed on the Moon and discovery the fifth Force. Yeah,
it wasn't like a stop the press this kind of thing. Yeah,
we didn't have President Trump commenting on this discovery yet
looking up at the Sun to see if that's were
(08:45):
the fourth the fifth force was no comment, but that
was the headline. The headline was scientists discover a new
force of nature, right like, um, like, if you didn't
know there were forces, they just found a new one. Yeah, precisely,
and so um that sounds like a big deal. But
(09:05):
I thought, since people out there might not be terribly
familiar with the forces that are out there and what
means to be a force and what we think of
from a physics point of view as a force, I
thought maybe we should start by talking about what the
four forces actually are. Yeah, the ones that we do
know about, right, the fat four of fundamental forces. That's right,
(09:26):
all these physics you'll be shocked to discover that there
is not consensus agreement among physicists about how many forces
we've discovered. Oh jeez, some say three, some say four,
some say five. There's controversy about how many there are now,
but they but now they've discovered another one. This controversy
about that too. All right, well, let's get into it, Daniel.
(09:47):
Let's talk about the forces we do know about. Um, so,
what are the four or three fundamental forces in the universe?
So off the bat, we think about the four fundamental
forces as gravity, the strong nuclear force, the weak nuclear force,
and electromagnetism. If you have to ask me, or you're
costed me on the street and ask me what the
(10:08):
four forces where, that's what I would say. You wouldn't
say there are only three. Well, you know, from a
particle physics point of view, we've done a pretty good
job of showing that electromagnetism and the weak force are
really one and the same. They're just two sides of
the same coin. In fact, in particle physics we refer
to them as the electroweak force, so that from that
(10:29):
point of view, you have three forces gravity, the strong force,
and the electroweak force. But traditionally the weak force is
kind of its own thing, and it's kind of is
because it has its own like particles that interacts with, right.
It doesn't use the photon like the electromagnetism forced us. Right.
But you know, if you want to talk traditionally, like historically,
(10:50):
electromagnetism is a new thing. They used to be electricity
and magnetism they were identified initially is totally separate phenomena
and then later understood to be too sides of the
same coin and merge into one that we now call electromagnetism.
So you know, years and years ago you might have
said five fundamental forces, that we emerged that down into four.
Now we've merged that down into three. So I think
(11:12):
three is actually the best description of you know, what
we currently understand. But that's not a widely held opinion.
Is this, like the Greeks thought that maybe there are
only three forces, like like women, fire were actually the same. Yeah,
except that we actually have more data than the Greeks.
Did we conclude this pretty conclusively and mathematically. Yeah. Okay,
(11:32):
so there are three or and or four. We'll say
there are three point five forces about that the difference.
This is not the kind of thing you want to
compromise on. This non negotiation. I'll give you three point
seven five plus you get the house on weekends. Maybe
you should, and maybe you would have more headlines that way. No,
(11:53):
And to remind people, electromagnetism is a force you're familiar with.
It's responsible for electricity from magnetism um and also for
chemical bonds. Is basically what holds your body together. It's
what makes the wall seems solid, you know. It's it's
responsible for most of the forces you actually feel. And
the weak force is not one you come and commonly feel,
(12:15):
but it is sort of related to the electromagnetic force. Yeah,
it's very closely related to electromagnetism. The particles that contribute
to the weak force are the W and the Z,
and you can think of them sort of like heavy photons.
Because they're heavy, it makes the force very weak and
it makes a very short distance scale. And so this
one really only comes into play for things like neutrinos
(12:36):
and radioactive decay. And I was actually talking to a
particle theorist this morning who said he didn't even consider
the weak force a force because you can't really feel it,
not even weakly. Not even weakly. Yeah, um, but I
consider it a force. Is a it's one of the
fundamental forces of nature, part of it because but it
gets lumped in with electromagnetism because like the math and
(12:59):
the the photon and the bosons, they are all sort
of act the same way, or they all fit into
the same mathematical box. Is that kind of why you
think they're all the same. Yeah, it just makes much
more sense mathematically if you put them all together in
the same box, and you can show that you start
from a certain set of particles and they get rotated
sort of by the Higgs boson and turn into the
(13:19):
particles we have. We should do a whole interesting podcast
episode about electroweak symmetry breaking. But just briefly, you know,
we have these forces, electromagnetism and the weak force, and
they're responsible for some of these physical effects. But then
of course there's also the strong force and gravity, right,
and so the strong force is the one that holds
the nucleus together, right, Like, without that one, all of
(13:40):
our nuclear which is fall apart. That's right. Remember, the
nuclei are protons and neutrons, and protons are positively charged
and so they repel each other, and the neutrons are neutral,
so they can't do anything to really help. So from
an electromagnetic point of view, the nucleus shouldn't even hang together.
We did a whole podcast episode about how the strong
nuclear force holds the nucleus to other So without the
(14:01):
strong force, we wouldn't have nucleari, we wouldn't have fusion,
we wouldn't have stars. It's pretty important. And gravity, that's
the that's the heavy one, right. Yeah, gravity is the
weakest force actually by all of these things. But it's
something you're familiar with because there are big sources of
gravity nearby, and so gravity will pull together anything that
has mass. You, your friend, your neighbor. You guys actually
(14:22):
feel gravity pulling on each other. Um, you just can't
really sense it because it's so small. Most of the
gravity you feel is with respect to the Earth or
if you're the oceans, with respect to the moon. Okay,
so those are the four or three and a half
forces um electromagnetism, weak force, strong first gravity, And that's
what we've known for a long time, right, I mean
at least maybe years is what we have known there
(14:47):
to be in nature. Like, that's it. You can't two
things can't pull or push on each other any other way.
These are the four ways that they can do it. Yeah,
and it's important to understand that these are descriptive. They're
just a description of all the stuff we've seen happen.
It's not like they come from some deep principle of
nature where we've derived a rule that there have to
be four forces or there can't be anymore. You know,
(15:08):
you could see tomorrow some new physical effect that can't
be explained by anything else, and that might be a
discovery of a new force of nature. It's just that
so far these forces have been able to describe everything
we've seen. But again, there's no theoretical limit. There could
be like forces and the other nineties are just super
duper duper feeble. We can't even sense them. Oh, I see,
(15:30):
up until Saturday, there was no indication in any of
the up until you went into that Starbucks to ask
people questions. Uh, there's no indication from any experiments that
humans have ever done that there was anything else going
on in the universe. Basically right like that, we hadn't
seen anything. They couldn't be explained by these four fundamental
(15:53):
forces precisely. And that's the way we like to do science. Right.
You see something new and weird, first thing you do
is say, can I explain it with things we know?
Because if you can, and that's the most likely explanation,
just a comes razor. And then you know, if you can't,
then you consider, well, maybe there's something new. I have
to add, something new to my theory, a new particle,
a new force, and new something to explain this new
(16:13):
phenomenon that nothing else I know can't explain. And you
guys felt pretty confident that there were only these four,
because you mean, you've done so many experiments over the
last seventy years, you know, smashing particles over and over
and over and over, that it didn't seem maybe likely
that there were more forces, right, I would have guessed
actually that there were. You know, if I had to guess,
(16:35):
gun in my head, are there more forces? I would
have guessed yes, And that doesn't happen. Hold hold the
gun to your head, Danniel. Somebody in a lab code
I'm sure Rappid from in the dramatic movie right now
my life, you know where physics, And the reason is
(16:56):
that there's a lot going on in the universe that
we know that we don't understand. End um. You know,
we wrote this book all about all the things we
don't know about the universe, and one of them is
that there's dark matter out there. And if there's dark matter,
that means it's a new particle, and a new particle
probably has a new kind of force, because we know
that dark matter doesn't interact with normal matter in any
way that we're aware of other than gravity. But we
(17:18):
think that dark matter probably does interact with normal matter
in some way in order to account for how much
we see it in the early universe. So I would
have guessed that there's a new force out there, like
a dark photon particle that mediates some new dark force.
But we don't have any actual evidence for it's just
a suspicion. Oh, I see all the experiments you've done
pointed to these four forces. But there are still things
(17:40):
out there in the universe we don't understand. Yeah, And
as always, there are patterns and the things we do
understand that suggests something is missing. To say, you know,
This would be a lot simpler if you found this
new particle. So you know, until Saturday, we didn't have
any evidence for that. All right, let's get into this
new discovery and what the news article was all about
and whether it did revolutionize our understanding of physics. But first,
(18:04):
let's take a quick break. Al Right, So what was
the actual article about that came out this weekend that
said that they found a new force of the universe.
(18:27):
What did they actually discover? Yeah, so the article was
misleading in several ways. You won't meet surprised to learn, um.
And the first thing is that this last weekend wasn't
really the most important moment. There's been a series of
papers from the same group in Hungary announcing discoveries for
the last few years, so they've been teasing this. No,
(18:49):
they've been trying to replicate their experiments. So maybe the
most important result came out in two thousand and sixteen
when they first saw evidence for what might be a
new particle, and this paper from recently just sort of
confirmed it in a different system. So let's talk about
what happened in two thousand sixteen, because I think that's
really the most important result. Okay, let's go back in time.
(19:10):
So wh then, what was the actual experiment and in
who who were these scientists and what did they actually discover. Yes,
so it's a group in Hungary and their experiment is
called the atom key Experiment a t O m k I.
The short version of the story is that they see
some things in their detector that they think are consistent
(19:31):
with a new particle, meaning something that they had never
seen before. Yeah, and something that, as we were talking
about before, they cannot explain using the fundamental forces and
particles that we know about. So that sounds exciting. It is,
And they've been doing it since two thousand sixteen, like
they've been talking about this for a while. Yeah, In fact,
they've been doing this kind of physics for quite a while,
(19:53):
and but this particular experiment is interesting. What they do
is they take a proton and they shoot at a
lithium nucleus and then it turns into burrillium because that's
one more atomic number up. So the nucleus sort of
absorbs the proton, but it's not just brilliant, it's like
excited burrillium. It's like has extra energy, so it's like
wiggling and dancing should we picture a dance that the
billium is doing? Which of the Fortnite dances is it doing?
(20:16):
You're the cartoon is you're the visual person. So I
want to see a doodle of dancing Burrellium. When we're done,
it's doing the Charleston. Let's go with that. And just
like you know how electrons can get excited up from
their ground state and then jump down a state. When
you jump down the state, you give off energy. And
so what they what we expect to happen is this
burrillium jumps down back into the ground state and gives
(20:38):
off energy in terms of a photon. Oh I see,
So the proton not just transforms it into a new element,
It transport forms it and gives it kind of extra
surplus energy. Yea. Then it has to get rid of yeah,
because the proton that comes in has a bunch of energy.
It's not just at rest proton just sort of hanging
out comes zooming in with a lot of energy. And
(21:00):
then the brillium nucleus which is then formed, has this
extra energy. It wants to get rid of it. And
so what you expect is for it to shoot off
a photon and then that photon would turn into a
pair of particles, an electron and a positron, and you
can measure the energy of that photon by finding the
electron oppositron and sort of adding them back up. Why
doesn't the photon just keep going as a photon, as
(21:21):
a little bit of light. Why does it have to
turn into an electron and a anti electron? Yeah, they can.
Photons like this can fly across the universe and just
go forever. But these guys have a special trick for
measuring it. In the way they measure the energy the
photon essentially is to induce it to turning into an
electron and an anti electron, so they can it helps
(21:42):
them measure the energy. How do you induce a photon
to not be a photon? Well, every time a photon
goes through matter, it interacts with the all the electromagnetic
fields inside that matter, and that tends to make it
pair produced. That we call it turning from a photon
into a pair of particles. You're gonna like slam it
against something, yeah, And the key thing is that when
you do that, you measure the energy of it, and
(22:04):
you can measure the mass of that particle and photons,
of course, don't have any mass. So you expect that
you get this electron and this positron. You add them
back up to reconstruct what the photon was like, and
you calculate what this mass was. You should get zero.
But what they see is a bunch of events where
it doesn't add up to zero. It adds up to
a different number. It adds up to a blob all
around the same number, around seventeen mega electron volts. So
(22:28):
where did this mass come from? Wit um? So photon
doesn't have mass, so you expected to split off into
an electron and an anti electron. You're saying that that
has to add up to zero. The mass of that
pair has to add up to zero. Yeah, But sometimes
they see something that they can't explain, which is the
(22:49):
mass of that pair adds up to something which is
not zero, which means that the particle that carried that
energy didn't have zero mass, It had non zero mass.
And so essentially what they think they've seen is like
another version of the photon, a different particle that does
have mass. Oh, they think that the photon they're seeing
(23:10):
is not a photon precisely. They think they call it
the X particle good branding. I was wondering if you'd
like that or not exert for like mysterious. We don't know,
you know, if it actually becomes something real, and I
guess they'll give it a real name. I think that
means that they're doing physics X at the end. So
that's the basic thing is that when they plot this
(23:30):
or the mass of this pair of electron and positrons,
they see a bunch of year zero where you expect
to see photons, but they also see a blob all
clustered together around seventeen mega electron volts. And that's the
kind of thing you would expect to see if there
was a new particle. There's something which wasn't a photon,
but brilliant was emitting this X particle when it went
(23:51):
down to its ground state. Oh like sometimes or usually
gives us a gives off a regular photon, but sometimes
you get a lot measurements of something that doesn't look
like a photon precisely. And that's exactly the kind of
thing you would expect to see if there really was
a new particle there. But it's not like there's something
terribly different going on here. I think maybe That's the
(24:13):
weird part for me is like, like I was following you,
it sounded like things I've heard before, but some of
that you're telling me that, like on irregular atom decaying,
suddenly there there's this weird new kind of particle coming out. Yeah,
that's precisely what they're suggesting. And remember that to be
consistent with everything else we've ever seen, it would have
to be pretty subtle. If this was happening a lot,
(24:35):
or shooting out some really powerful rays, or happening really often,
then we would have noticed. Are already we studied atomic
nuclei great detail. We have a pretty good understanding of
how this works. So for this to evade all other
previous experiments, it have to be pretty subtle. Not something
in particular to the beryllium or the lithium. It's just
(24:56):
something that nobody had that had flown under people's it are.
It's not like these um they were taking like super
exotic matter and doing experiments with experiments with it and
they found something new. It's like they were doing something
pretty what sounds pretty regular run of the mill physics. Yeah,
and what they did last weekend, this new result that
(25:17):
just came out is that they reproduced the same results
using helium. So instead of brillium, they excited helium into
a new state and when they saw a decay, they
found a few of these examples of this X particle
that looked just like in the brillium decays, like helium
and helium balloons have some sort of secret particles in them. Yeah,
(25:38):
but you know, if it's real and it's actually there,
it's just turning into electrons and positrons and you can't
tell the difference. So if this thing is real, and
then it could be happening around us all the time,
but it wouldn't make much difference to your world. I mean,
the world with four forces or five forces doesn't look
very different to you. And what did they say in
the paper? Are they just saying like, hey, we look
(26:00):
better than everybody else and so we found it. Or
are they saying, you know, nobody's looked in this range before,
or are they saying this is an interaction like a
reaction that nobody had studied closely before to see it. Well,
nobody else has ever seen this before. Only this one
group from Hungary has seen this before. Now, other people
(26:21):
have done nuclear physics experiments other people have looked at burrillium,
other people have looked at helium. Nobody's ever seen this before. Now,
when they put out the paper in two thousand and sixteen,
nobody really paid attention. They were like, huh, whatever, that's interesting,
but it's sort of in conflict with other results because
nobody had ever seen this thing before. But then a
group of theorists here you see Irvine, actually, Jonathan Fang
(26:44):
and Tim Tate, they read this paper and they thought,
that's interesting. Can we find a way to explain this
result in terms of a new particle that also doesn't
break all the other results that we've seen. Can we
find a reason why all those other experiments wouldn't have
seen this particle yet they looked at it. And Jonathan's
a friend of ours, right we you're a friend of Jonathan,
(27:04):
and I've met Jonathan and he's been in our videos
that we've made for YouTube before, which is why I
was like, I saw the article and then I saw
his name. I was like, what, I know this guy
because it was his paper that got this group a
lot of attention. They published their paper and nobody really
paid attention. But then Jonathan showed that their result could
be consistent with a new particle and also be consistent
(27:25):
with all the other experiments. Essentially, Jonathan found a way
to explain away all the other results because all the
other experiments have slightly different configurations or use a different
energy range or a different kind of particle a different
kind of detector. So Jonathan found a theory that explained
this new result and also was consistent with everything we've
seen before, and that is what made it exciting. I
(27:45):
feel like that's really gutsy, you know, like if you
read a paper with a crazy idea that probably clearly
sounds like they just made a mistake to be like Nope,
I'm gonna sit down and I'm gonna double down and
find a theory that might explain weird circumstance. Yeah. I
think it actually sort of went the opposite direction. They
were like, well, here's a crazy result. It's ruled out
(28:07):
by all these other experiments, right, let's do the calculation,
let's estimate, let's see if these other experiments actually are
in conflict with this one, or if we can find
a way to wiggle this one out. I think it
started as an exercise and then they realized ham there
really is an opening there. There's a way that you
can explain this new result that doesn't conflict with the
other ones. And that's when they got excited. Do you
(28:27):
mean it was kind of like Jonathan was sitting on
a Sunday and he's like, I could do the cross
word puzzle today, or I could just you know, pass
some time working out some equations for this experiment. Um.
I don't know. I think it was an exercise at
the time. He was working with his post doc Flip Tonedo,
who's also a friend of ours on the podcast and
is now a professor e C Riverside, and they were
(28:48):
just sort of working through this as an exercise and
then discovered, hey, maybe this overlooked piece of evidence from
Hungary is actually evidence for a new force of nature.
That was an exciting moment for them. Interesting. If he
hadn't done that, then people might have just ignored this experiment. Yeah, yeah,
I think so. I think it was the attention of
this frankly world class group of theorists and this reasonable
(29:11):
argument for how it might be a big discovery that
pointed the world's scientific attention to this group and Hungary.
All right, well, we'll have to ask Jonathan over a
beer or something, how he got in, how he found
this article and what made him get interested in it.
But yeah, let's talking about the result itself and whether
it's significant and whether it is actually a new force
(29:33):
of nature. But first let's take a quick break, all right, Daniel,
So have they found a new fifth force or I
(29:53):
guess four and a half fource of the universe. I
would say it's way too early to tell. I mean,
first of all, I don't think we can even really
conclusively say that they have seen a new particle. And
then there's the follow up question of if it is
a new particle, is it a new force? Also, so
you you have doubts about or you want to see
more evidence about whether or not even found anything. And
(30:16):
then there's actual deeper questions about whether it actually means
there's a new force. That's right, this result only comes
from one team, this team in Hungary. And before you
really believe that a particle exists, do you want to
see it replicated by an independent team? You want to
see another group that has a different setup and maybe
different potential biases, make the same measurements and see the
(30:37):
same thing. I mean, if it's a real thing in nature,
you should be able to see it in more than
one place. It's like when we discovered cold fusion, that
group in Utah. Other groups immediately went out to see
if they could reproduce it, and nobody could, which is
how we knew that it was bogus. And that doesn't
mean necessarily malfeasance, you know, it doesn't mean that they're
lying to us, But it's a There's a lot of
ways to accidentally bias your result or introduce a mistake,
(31:02):
and that's why we cross check things to science. So
where are we at now? Have people tried to replicate
it or has just nobody tried And so that's why
it's an open question. Like it doesn't sound like a
super difficult experiment, isn't like you don't need billions of
dollars for it. You don't need billions of dollars. You
need some sort of particle accelerator so you can get
these protons up to the right energy, and then you
(31:24):
need a detector that can transform this particle into your
positiron electron pair and measure it precisely. And you also
just need time and interest. And so there are a
few groups out there that are interested in potentially reproducing
this measurement using slightly different equipment, but nobody has done
it yet, and until that happens, I don't think anybody
in science is really going to take this result seriously. Well,
(31:46):
it's kind of a weird incentive, right, because like, if
I'm a physicist, what's my incentive to being the second
guy who confirms the first guys or first girls or
gals experiment? You know what I mean? Like, it's like
it's a weird thing to jump into, you know, because
you want to get all the glory, and if you
disprove it, then you know, you would you probably wouldn't
(32:07):
get munch of glory either. That's an interesting question, and
I think that goes to like who would get the
credit for this kind of discovery, you know? And should
it go to the Hungarian folks? Should it go to
Jonathan and those folks for recognizing the importance of this,
should it go do a new team that verifies it?
Should you split it three ways? I'm not sure. To
me for having a podcast about it, I'm not sure.
(32:29):
And you know, there's also a question of sort of
priorities and credibility you know, everybody out there's a lot
to do in science and a long list of experiments
they'd love to get done, and given infinite funding, sure,
I'd like to see this thing happen, But you know,
is it the most important thing that these other groups
can be doing with their time? And also, does anybody
really believe this result? This Hungarian group has sort of
(32:52):
a I mean there are whispers and hallways and physics
departments about a checkered past from this group, claiming discoveries
which didn't pan out. Oh man, gossip gossip. There is
physics gossip. And you know there's people who have now
retired and I think passed away who used the same
facilities and made a lot of claims about new particles
(33:13):
they thought they discovered, which then sort of went away
and no longer part of this team, of course because
they've passed on. But it sort of lingers. The questions
linger about whether results from this facility can really be trusted.
I'd like to see that TV show Gossip Girl for
for physics. And you know, in the end, the results
speak for themselves, either you believe them or you don't.
And and importantly, nobody has found a flaw in their work.
(33:36):
People have combed through the details and nobody has found
a mistake. And also people have worked really hard to
try to explain the results using just standard physics, using
the four forces we know, and nobody has been able to.
So it's either a very subtle mistake or it's real.
You're kind of saying that it's suspect. But if it's
(33:56):
a hoax, it's a really good hoax. I'm not saying
it's a hoax, right. Hoax implies that these folks are
tricking us. I think they're doing honest work. Oh, I
see right. But if it's a mistake, it's a really
well hidden mistake. If it is a mistake or not, no,
And it's really easy to make subtle mistakes. You know,
these detectors only see a fraction of the events, and
so you have to make some assumptions about the ones
(34:17):
you missed, and it's very easy to introduce biases. We
have lots of examples in particle colliders, for example, where
we see bumps in our data and we think, oh
my gosh, maybe that's a new particle, and it turns
out it came from a complicated series of of influences
from this and that me other which produce a bump
in your data. So it's easy to produce false bumps.
And so what you really just need is a totally
independent cross check. And you would need that for any group, right,
(34:39):
even if this was a very well respected group from Harvard,
you would definitely need independent confirmation before you believed it.
All right, Well, let's get into the details a little bit.
I think we have time and talk about to the
idea that Jonathan proposed, or that this group proposed at
the same time, was that like, maybe this is a
new particle that we're seeing. Maybe this particle has a
(35:01):
new force of nature attached to it. Yeah, and that's
really sort of just interpretation. All we know is if
this particle is real, it decays into an electron and
positron pair, and that means that it has to have
into your spin because the electrons and positrons are spin
half and so they have to add up to either
spin zero or spin one or whatever, but into your spin.
(35:23):
And that's the kind of particle we call a boson.
Bosons have intoed your spin. And so this looks like
it's a boson, that's right. And so the most conservative
thing you could say, is if this is real, it's
a new boson. Is a photon a boson. A photon
is a boson, the W, the z, bluon, all these
particles are boson's. Every boson we know of is associated
(35:43):
with the force. Photon carries electromagnetism, that W and Z
carry the weak force, gluons carry the strong force. If
gravity is a quantum force, it would have a graviton,
which is a boson. So this is there's this association
between bosons and forces. Okay, and you think so you
you sort of know it's a boson because of the spin,
(36:04):
but do you think it might be a new boson
because it weighs differently than all the other bosons you
know about? Precisely? But I think there's some disagreement in
the physics community about whether every new boson has to
be a force. For example, we discovered a new boson
a few years ago, the Higgs boson. Is the Higgs
boson represent a new fundamental force of nature. Some theorists
(36:27):
say yes, Some theorists say no, because the Higgs boson
also doesn't just fall out of requiring what we call
a local gauge symmetry, which is a fancy jargon for
having a certain kind of math. But how do you
know it's not just a like a W boson that
weighs differently, or like a boson W boson that eight
too much for lunch. This is much much lighter, right.
(36:48):
The W boson is about, let me do some math
um four thousand times heavier than this new X particle.
So it has to be a W boson on a
strict diet. It's like intermittent fast W boson. It's a
W boson that's skip lunch. Well, that's a good question.
So you also call that in a different like like
(37:09):
a W boson that ways less would still be a
new boson. W boson that wass less would still be
a new boson. Like we are looking right now for
new versions of the W that have different masses. That
would be a different particle, because the mass of the
particle really shapes its identity. It's part of what we
call a particle. And you know, like finding a heavier
version of the electron, that would be a new particle.
(37:29):
It's who they are, it's who they are um. And
so there's not an agreement about whether every boson really
represents a new force or not. Even if you find
a heavier W Boson, that doesn't mean there's a new force.
It just means you found a heavier W Boson. That's right.
But of course it sounds cooler to discover a new
force than a new particle, and so I think that's
why some people described in the media is like, discovery
(37:51):
of a new force of nature sounds sexier. It it
focus grouped better than discovery of a new particle of nature.
You would get more clicks if you say we found
any force then you say and then if you say
we find a new Boson, that get lunch. That's right,
But it could be It could be that there is
a new fundamental force out there and this boson carries
that force, and that this is the first piece of
(38:12):
evidence for the discovery of this new particle, which is
the clue to the new force, which tells us something about,
you know, the way the universe works. Although I think
you would get a lot of clicks if you wrote
the headline as you won't believe what this boson life
now with its new diet. That's right, But you know
there's also competing forces here because physicists are trying to
(38:32):
discover new forces, we're also trying to get rid of forces.
You know. One of our goals is to describe all
the forces in terms of one mathematical structure, Like we
combined electricity and magnetism into electromagnetism, and then with the
weak force into the electro week. We'd love to find
the grand unified force that encapsulates everything. So on one hand,
we want to find more forces, and then on the
(38:54):
other hand, we want to sort of shoehorn them together
into one framework. It's like when you're trying to clean
up your kid's room and you got everything sort in
the closet, and then the kid comes up and says, look,
I found this toy, and you're like, great, well. It's
sort of like when you're trying to solve the jigsaw puzzle.
First you want to get all the pieces and categorize them,
(39:14):
and then you want to see if they fit together
into one nice picture. But you can't do that if
you don't have all the pieces. And so we desperately
want to figure out are there other pieces out there
that we're missing? Because we know this a lot about
the universe. We haven't understood. When you get a headline
like this, you're both kind of excited but also like
you've grown a little bit, like, oh, that means that
means we're behind. But hey, isn't it exciting that we're behind.
(39:37):
We're always behind. It's not like this a schedule for
discoveries of the universe. We're never gonna understand everything behind
one of my jet packs yesterday, yesterday. You know, we
are always going to be behind. So it's always exciting
to hear about more physics to understand. All right, Well,
it sounds like the answer here is stay tuned. Sounds like, um,
(40:00):
they found something amazing, or maybe they found something but
it's it's not that revolutionary, or maybe they maybe they
didn't find anything. Maybe it's just something that there that
people are overlooking. Yeah, stay tuned for independent confirmation. Until
we get that, you really should just put a pin
in it and think about it as a cool result
that maybe we'll understand one day. Right, until then, we
(40:22):
still only have three and a half fundamental forces three.
That's my final offer. Let's get three point six and
then weekend end this podcast Daniel done, especially after we
account for Lawyer's fees on the forces. All right, Well,
hopefully that answered people's curiosity and questions about this headline
that came over the weekend. Yeah, so thanks for sending
(40:44):
in your questions. If you see something in the Science
News that you don't understand, please send it to us
at Questions at Daniel and Jorge dot com. We'll break
it down for you. And remember Daniel answers Twitter and email,
but he doesn't answer Instagram, Instill what instead? You know
what the kids are using? But I think you do
answer TikTok? Do you do TikTok? I don't know what
(41:08):
that is, but I definitely do it. Loll the kids
are doing it. I mean I'll put a lab coat
on and make one of those ticker talkers. There you go.
Well all right, well, we hope you enjoyed that and
see you next time. Thanks for tuning in, and thanks
for lending us your brain for fifty minutes. Before you
(41:37):
still have a question after listening to all these explanations,
please drop us a line. We'd love to hear from you.
You can find us on Facebook, Twitter, and Instagram at
Daniel and Jorge that's one word, or email us at
Feedback at Daniel and Jorge dot com. Thanks for listening
and remember that Daniel and Jorge Explain the Universe is
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Hosts And Creators
Daniel Whiteson
Kelly Weinersmith
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