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Antimatter – The Mirror Universe · Talking Science

0:00
Right now, as you're listening to this, microscopic
0:02
particles of antimatter are raining down from
0:05
space. Yeah, it sounds completely absurd, doesn't
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it? It really does. I mean, they are passing
0:10
through the roof over your head and they're actually
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annihilating inside your body right now. Which
0:14
is just a wild concept to wrap your head around.
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Totally. Because the very word antimatter just
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feels like, I don't know, something that only
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exists to move a science fiction plot forward.
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Right, exactly. You picture glowing warp drives
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or, you know, someone in a uniform shouting about
0:29
a containment breach. Yeah, it definitely carries
0:32
that Hollywood sheen. We have totally been conditioned
0:35
to think of it as just a fictional trope. But
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it's not. No, not at all. Antimatter is a 100
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% factual part of our universe. It is routinely
0:47
created in laboratories. It's part of the natural
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decay of the world around us. Right. And honestly,
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its sheer existence is tied directly to the deepest
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mystery of why human beings, or any physical
0:59
objects at all, even exist. And that is exactly
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our mission for this deep dive today. We are
1:05
taking all the sources and stripping away the
1:07
science fiction tropes to look at the actual
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physics. Because the reality is so much better.
1:13
It is. How it works, how we discovered it, and
1:16
what it implies about the birth of the universe.
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It's infinitely stranger than... anything a screenwriter
1:22
could invent. It really is. And to appreciate
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just how strange it is, we need to take a quick,
1:28
unhurried look at the baseline first. Okay, the
1:31
baseline. So ordinary matter. Right, the ordinary
1:33
matter that makes up you, me, and the device
1:36
you're playing this audio on. Most people are
1:38
familiar with the basic model of an atom, right?
1:41
Yeah, you have a nucleus in the center. Exactly,
1:43
a nucleus in the center, and orbiting around
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that nucleus are electrons. And the defining
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feature of those electrons... well, at least
1:50
for our story today, is that they carry a negative
1:52
electric charge. Yes. They are negatively charged,
1:55
and the protons in the nucleus are positively
1:58
charged. Right. They balance out. Precisely.
2:00
That balance of positive and negative is the
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absolute bedrock of chemistry, biology, essentially
2:07
everything we can see and touch. And for a long
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time, physicists just kind of thought that was
2:11
the end of the story, right? They did. But then
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in the late 1920s, you have this British physicist
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named Paul Dirac. And he was sitting at a desk,
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not, you know, running physical experiments in
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a lab, but doing highly complex mathematics.
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Right. I read about this. He was trying to force
2:27
a sort of mathematical marriage between two areas
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of physics that notoriously hated each other.
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That is a great way to put it. Yeah. It was quantum
2:34
theory, which governs the weird behavior of the
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super tiny. Einstein's theory of relativity,
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which deals with things moving incredibly fast.
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Right. Dirac wanted a single elegant equation
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that could describe an electron moving at nearly
2:49
the speed of light. Which is no small task. No.
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But he succeeded. He wrote an equation that perfectly
2:54
unified those concepts. But, and here's the catch,
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there was a bizarre mathematical artifact hidden
3:00
inside his work. Yeah, this part reminds me of
3:02
basic algebra. Oh, how so? Well, if I ask you
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for the square root of 4, the obvious answer
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is 2 because 2 times 2 is 4. Right, simple enough.
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But negative 2 is also a technically correct
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answer because a negative times a negative is
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a positive. That is actually the perfect way
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to visualize what happened to Dirac. His energy
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equations basically had two valid solutions.
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Okay. One described the ordinary negative electron
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that everyone already knew about. But the math
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stubbornly insisted on a second solution, a sort
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of mirror image particle. A mirror image? It
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had the exact same mass, the exact same properties,
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but an opposite positive charge. A positive electron,
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which at the time must have sounded insane. I
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mean, it was considered physically impossible.
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Completely unheard of. Many physicists actually
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told Dirac to just ignore the second solution.
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Just pretend it's not there. Exactly. They assumed
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it was just a quirk of the math, a leftover artifact
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that had no bearing on reality whatsoever. But
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Dirac, he trusted his equations. He stuck to
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his guns. He did. He argued that if the math
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required this mirror image particle to exist,
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then nature must actually contain it somewhere.
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It is like, you know, balancing your monthly
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budget at the kitchen table and your spreadsheets
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perfectly balanced, but only if you acknowledge
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a secret. parallel bank account you have never
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once seen yes you would assume you just carried
4:26
a one somewhere and messed up the math but just
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a few years later dirac was proven completely
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right He was. In 1932, experimenters were studying
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cosmic rays. Those are high energy particles
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crashing into Earth's atmosphere from deep space.
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Right. And they found a track in their detectors
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that just defied explanation. It curved exactly
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like an electron, meaning it had the exact same
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mass, but it curved in the wrong direction. Because
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it was positively charged. Exactly. They had
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found Dirac's mathematical ghost. They named
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it the positron. And this just blew the doors
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off our understanding of physics. I can imagine.
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Because it meant that for essentially every fundamental
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particle in the universe, a mirror image antiparticle
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exists. Wow. So if you have a negative electron,
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you have a positive positron. Yep. And if you
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have a positive proton, you have a negative antiproton.
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Exactly. Which means you could theoretically
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string those together, right? Like you could
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build antihydrogen. Oh, absolutely. You could
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have an anti -carbon atom, anti -water, an entire
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anti -chemistry. could build a perfect mirror
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version of the material universe. That is wild.
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And physicists have actually done the first steps
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of this. They have assembled anti -hydrogen right
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in the laboratory. But, and this is a big but,
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you can't just leave a jar of anti -hydrogen
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sitting on a lab bench. No, no, you definitely
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cannot. Which brings us to the core reason science
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fiction writers are so obsessed with this stuff.
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What actually happens when this mirror world
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comes into contact with our ordinary world? It
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is hands down the most dramatic family reunion
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in physics. When an ordinary particle meets its
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exact antiparticle, say, your ordinary negative
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electron bumps into a positive positron. Right.
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They do not bounce off each other. They do not
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bond to form a new molecule. They mutually annihilate.
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And we use the word annihilate a lot in everyday
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conversation to just mean like destroy. But in
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particle physics, it is a very specific absolute
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mechanism, isn't it? It is. It means both particles
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completely vanish from physical existence. 100
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% of their mass is converted instantaneously
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into pure energy. Pure energy. Usually this energy
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takes the form of highly energetic light. Specifically
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gamma rays. And to understand why that is so
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explosive, we have to look at Einstein's most
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famous equation, right? E equals mc squared.
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Yes. Energy equals mass times the speed of light
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squared. That equation is the rule book for this
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explosion. Okay, break that down for us. Well,
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the m is the physical stuff of the electron and
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positron. It is being converted entirely into
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e, the energy. Right. But the multiplier in that
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equation is what makes it so terrifying. Because
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c is the speed of light. Which is, what, roughly
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186 ,000 miles per second? Exactly. That is already
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a colossal number. But the equation tells us
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to square it. So you multiply 186 ,000 by 186
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,000. Right. And the resulting number is astronomical.
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Because that multiplier is so large, converting
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even a tiny microscopic speck of mass yields
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an absolutely enormous amount of energy. Gram
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for gram, it's the most concentrated thing we
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know of. Oh, by far. Matter -antimatter annihilation
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is the most concentrated, efficient release of
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energy known in nature. It is orders of magnitude
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more powerful than the nuclear reactions inside
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an atomic bomb, or even the core of our sun.
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Okay, let me pause and deduce something here
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because this brings up a huge question. If we
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know this is the ultimate most concentrated energy
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source in the universe, why aren't we using it?
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Oh, the power plant question. Yeah. Why don't
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we have, you know, antimatter power plants providing
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limitless clean energy to our cities? it comes
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down to a really harsh reality of thermodynamics.
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You see, antimatter is not a fuel you can just
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mine from the Earth. Right, you can't just dig
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it up. No, you have to manufacture it. And the
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fundamental laws of the universe dictate that
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you can never get more energy out of a system
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than you put into it. So the energy required
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to create the antimatter in the first place is
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vastly greater than the energy you get back when
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it annihilates. Wow, okay. Yeah. You have to
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pour city -sized amounts of electrical power
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into massive particle accelerators just to generate
8:32
a few fleeting atoms of antimatter. So as an
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energy source, or like a battery, it's a staggering
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net loss. Exactly. It will always cost you more
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to make than it ever provides. That makes total
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sense. But it introduces an immediate, almost
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comical engineering nightmare. Oh, the containment
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problem. Yes, because if you are a physicist
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and you want to study antimatter... You have
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to hold it somewhere. But the moment your antimatter
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touches the ordinary matter of your container.
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It annihilates. Right. Are physicists just making
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it and watching it instantly destroy their equipment?
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It's a great question. That was the grand challenge
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for facilities like CERN in Switzerland. They
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had to figure out how to trap. the untrappable.
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And their solution is a masterclass in applied
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physics, from what the sources show. It really
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is. First, they have to actually manufacture
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the antiprotons and positrons. And to do that,
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they basically run Einstein's equation in reverse.
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I love that. Running it in reverse. It's true.
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If E equals mc squared tells us that mass can
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turn into an explosion of energy, the reverse
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is also theoretically true. A massive concentration
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of energy can condense into physical mass. So
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they take ordinary protons, accelerate them to
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nearly the speed of light in a massive ring,
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and just smash them into a block of metal. Yes.
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And the violence of that collision creates a
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microscopic concentration of pure kinetic energy.
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Wow. For a sleeting fraction of a second, the
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conditions actually mirror the extreme energy
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of the early universe. And out of that pure energy...
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New particles just condense into existence, including
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matter -antimatter pairs. But now they are flying
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out of the crash site. How do they catch them
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before they hit the walls of the machine? They
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use something called a penning trap. Because
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these particles carry electrical charges, scientists
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can manipulate them using incredibly strong,
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carefully tuned magnetic and electric fields.
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So it's like an invisible magnetic cage. Exactly.
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The antimatter particles are pushed and pulled
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by the magnetic field so that they hover perfectly
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in the center of a vacuum chamber. They just
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float there untouched. Right. And the vacuum
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is absolutely critical. They have to pump out
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essentially every single stray molecule of regular
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air. Because if an antiproton simply bumps into
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a random oxygen molecule wandering through the
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chamber... The experiment ends in a flash of
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gamma rays. Right. Back to annihilation. Yep.
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But by perfectly balancing this magnetic cage
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in a deep vacuum, they've managed to hold on
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to complex antimatter, like antihydrogen, for
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minutes at a time. Which, in the world of high
11:05
-energy physics, is an absolute eternity. It
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really is. It gives them the time they need to
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actually interrogate the mirror world. They can
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shine lasers on the antihydrogen to see how it
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absorbs light. They can test how it reacts to
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outside forces. Exactly. And one of the most
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fascinating tests is gravity. Physicists seriously
11:23
wondered if antimatter might fall, you know,
11:25
up. Wait, really? Fall up? Yeah. If it was a
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perfect mirror, maybe its gravitational interaction
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was mirrored too. It's a very valid hypothesis.
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That would be so weird. But what happened? Well,
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the experiments at CERN recently confirmed that
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antihydrogen falls downward, reacting to Earth's
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gravity exactly the same way regular hydrogen
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does. So at every turn, it seems to be a perfect
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symmetric reflection of our ordinary matter.
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It does. But physicists are utterly obsessed
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with finding a flaw in that reflection. Right.
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They keep running these incredibly difficult
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experiments looking for some microscopic difference
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in how antimatter behaves compared to matter.
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Why are they so desperate to find an asymmetry?
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Because if the mirror is truly perfect, then
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none of us should exist. Okay. That is a huge
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statement. It is. But the fact that you and I
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are having this conversation right now is a glaring
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violation of that perfect symmetry. Take us back
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to the moment the universe began to explain why.
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Okay, so in the first moments of the Big Bang,
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the universe was an unimaginably dense, incredibly
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hot soup of pure energy. Right. As the universe
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expanded and cooled, that pure energy began to
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condense into mass, just like what happens inside
12:35
the particle colliders at CERN, but on a massive
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cosmic scale. And based on everything we know
12:40
about physics, energy always condenses into equal
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pairs. If you make a particle of matter, you
12:46
must make a particle of antimatter. Which means
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the early universe should have contained exactly
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50 % ordinary matter and 50 % antimatter, a perfectly
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balanced ledger. But that is a catastrophic scenario.
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I mean, if everything is packed tightly together
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and every single particle of matter has a mirror
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twin of antimatter right next to it. They're
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all going to collide. They would mutually annihilate.
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Yes. The entire young universe would have spent
13:11
its first moments engaging in a blinding, complete
13:14
cancellation. The matter and antimatter would
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have converted each other entirely back into
13:20
light. Leaving nothing. Exactly. The universe
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would have continued expanding as an empty, featureless
13:25
void filled with nothing but radiation. No galaxies,
13:28
no carbon, no biological life. And yet we can
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look out our windows. We can look through telescopes.
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The universe is incredibly full of ordinary matter.
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The stars, the planets, the dust clouds. Right.
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But as far as we can measure, it is practically
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devoid of antimatter. Which forces physicists
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to a mind -bending conclusion. It does. In the
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absolute earliest fractions of a second of creation,
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some unknown mechanism broke the symmetry. The
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scales tipped. The analogy that helps me picture
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this is a massive cosmic dance. Oh, I like this
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one. Yeah. Imagine a dance floor with a billion
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women representing antimatter and a billion and
14:06
one men representing ordinary matter. Okay. The
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music stops and everyone is told to find a partner.
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So a billion pairs form. Exactly. A billion pairs
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find each other and they mutually leave the dance
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floor in a flash of light. But there is one man
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left standing alone. Because there's no partner
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for me. Right. One single particle of ordinary
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matter out of a billion that had no mirror twin
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to annihilate with. And that single leftover
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dancer is the foundation of reality as we know
14:34
it. Every single star in the Milky Way, every
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grain of sand on Earth and every single atom
14:38
in your body is built entirely from that faint
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surviving leftover surplus. It's just staggering
14:45
to think about. We are basically a rounding error
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in the cosmos. We are the microscopic residue
14:50
that survived the Great Annihilation. Yeah. But
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do we actually know the mechanism? Do we know
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what tipped the scales to create that extra particle
14:59
of ordinary matter? We don't. It is known as
15:02
the baryon asymmetry problem, and it remains
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one of the most profound open questions in modern
15:09
physics. Wow. Our current theoretical models
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simply do not produce an imbalance large enough
15:15
to explain why a whole universe of matter survived.
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And that perfectly explains the obsession at
15:20
CERN. Exactly. If they can find just one tiny
15:23
flaw in the mirror, maybe antihydrogen decays
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at a slightly different rate than regular hydrogen,
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it might be the breadcrumb that leads us to understand
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why the universe favored matter. They're hunting
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for the glitch in the reflection that allowed
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existence to happen. It is the ultimate existential
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detective story. Beautifully said. But as grand
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and cosmic as all of this is, we should point
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out that antimatter is not just locked away in
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Swiss laboratories or theories about the Big
15:47
Bang. No, not at all. It is deeply practical
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and is being used right now in local hospitals.
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This part is amazing. It is incredibly grounded
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when you look at medical diagnostics. There's
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a very good chance that you... Or someone you
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know has had antimatter directly injected into
16:04
their bloodstream to save their life. When I
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first read about this in the sources, it completely
16:08
threw me. We are talking about the PET scan.
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The PET scan, yeah. The P and the E stand for
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positron emission. Positron emission tomography.
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A machine literally named after antimatter. But
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how does this actually work without causing a
16:22
catastrophic explosion inside the patient? Well,
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it relies on the precise mechanism of annihilation
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we talked about earlier. When a patient goes
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in for a PETES scan, usually to locate a tumor
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or see how cancer is spreading, they're given
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an injection of a specialized radioactive tracer.
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Okay. Crucially, this tracer is attached to a
16:40
simple sugar, like glucose. And this is where
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the biology meets the physics. Why attach it
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to glucose? Because fast -growing, highly active
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cells like cancer cells consume vastly more energy
16:51
than healthy tissue. They're absolutely starving
16:54
for sugar. Oh, I see. So the patient's body naturally
16:56
shuttles that radioactive glucose straight to
16:59
the site of the disease. Exactly. The cancer
17:01
effectively paints a target on itself by hoarding
17:04
the sugar. That is brilliant. Now, the radioactive
17:07
isotope that was attached to that sugar is unstable.
17:10
As it naturally decays inside the tumor, it emits
17:13
impositron. Wow. So a particle of antimatter
17:16
is born right there inside the diseased tissue.
17:19
Yes. But it can't last long. Because the patient's
17:22
body is made entirely of ordinary matter. Right.
17:25
The environment is hostile to it. The positron
17:27
travels barely a fraction of a millimeter before
17:30
it crashes into an ordinary electron inside the
17:32
patient's tissue. And they mutually annihilate.
17:34
They do. Their mass vanishes and turns into pure
17:37
energy. E equals mc squared happening inside
17:40
the human body. Exactly. But on a microscopic,
17:43
entirely safe scale. Now remember the physics
17:46
of that annihilation. When the electron and positron
17:49
destroy each other, they release energy in the
17:51
form of two gamma rays. And because of the laws
17:54
of momentum, those two gamma rays shoot out of
17:57
the body in exactly opposite directions. A perfect
18:00
180 degree line. And the patient is laying inside
18:03
a giant ring of detectors. Yes. The PE scanner
18:07
ring detects those two flashes of gamma radiation
18:09
hitting opposite sides of the machine at the
18:12
exact same time. Oh, wow. So the computer simply
18:14
draws a line between those two hits. It triangulates
18:17
the explosion. Millions of times over. Exactly.
18:19
And by mapping exactly where these microscopic
18:22
antimatter annihilations are happening, doctors
18:25
can build a highly detailed, real -time, three
18:28
-dimensional image of exactly where the cancer
18:31
is metabolizing sugar. That is just a beautiful
18:33
piece of engineering. It really is. The exact
18:35
same physical process matter violently annihilating
18:39
antimatter that science fiction writers use as
18:41
a doomsday weapon to blow up alien spaceships
18:44
is quietly, safely, and routinely being used
18:47
by oncologists to target cancer and save human
18:50
lives. It perfectly illustrates how moving from
18:52
fiction to real physics doesn't make a concept
18:55
less interesting. It makes it infinitely more
18:57
profound. It really does. I mean, looking at
19:00
the journey we've just charted, antimatter began
19:03
as a bizarre quirk in the math on Paul Dirac's
19:06
chalkboard, an impossible positive electron that
19:09
basically demanded to exist. Right. Then we recognized
19:12
it as a violently destructive force, the purest
19:15
expression of Einstein's energy mass equivalence.
19:18
From there, we learned how to engineer it, suspending
19:21
atoms of anti -reality in invisible magnetic
19:24
cages inside deep vacuums. And finally... We
19:28
harnessed that violent annihilation into a life
19:30
-saving medical tool. It has transitioned from
19:33
a mathematical ghost to an everyday tool. It's
19:35
incredible. But I think the most compelling thing
19:38
about antimatter, even what we know about it,
19:40
but what we still don't know. Oh, what do you
19:43
mean? Well, we talked about the asymmetry, the
19:45
idea that all the antimatter in the early universe
19:48
was annihilated, leaving only our ordinary matter
19:50
behind. Right, the one leftover dancer. But there
19:53
is another highly provocative theory that physicists
19:56
occasionally entertain. What if the imbalance
19:59
wasn't universal? What if the universe simply
20:01
sorted itself out? Sorted itself out? You mean,
20:05
what if there are pockets of antimatter that
20:07
survived? Exactly. The laws of physics allow
20:10
for anti -chemistry, anti -stars, anti -planets.
20:13
Okay. What if... far beyond the reach of our
20:16
current telescopes in the deepest reaches of
20:19
the cosmos there are entire primordial anti galaxies
20:23
galaxies burning with anti stars orbited by anti
20:27
-planets. That is terrifying and amazing. And
20:30
to a telescope, the light they emit would look
20:32
exactly like ordinary light. We wouldn't know
20:35
the difference just by looking at them. We would
20:37
only know if an ordinary star wandered into that
20:40
anti -galaxy. Exactly. The boundary line where
20:42
those two domains meet would be an absolute inferno
20:45
of annihilation radiation. Yeah. We haven't seen
20:47
evidence of those boundaries yet, so if anti
20:49
-galaxies exist, they are incredibly far away.
20:52
But the mathematics that started with Dirac on
20:54
a chalkboard still leaves the door open so next
20:57
time you look up at the night sky just think
20:58
about that somewhere out there floating in the
21:02
dark a perfect mirror image of our universe might
21:05
be waiting in the distance