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The Large Hadron Collider – Smashing Atoms to Understand Everything · Talking Science

0:00
Picture this. You are 100 meters underground
0:02
right on the border of France and Switzerland.
0:04
Yeah, deep under the countryside there. Right.
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And there is this massive 27 kilometer circular
0:10
tunnel. I mean, it's literally big enough to
0:12
run a commercial train right through the middle
0:13
of it. Oh, easily. It's a massive physical space.
0:16
And down in this tunnel, it is maintained at
0:18
a temperature that is actually colder than the
0:20
vacuum of... deep space but uh here's the wild
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part at very specific points inside that freezing
0:27
ring humanity is routinely generating conditions
0:30
that are hotter than the center of the sun it
0:33
sounds like science fiction honestly yeah But
0:35
it's very real. It really does. And the goal
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here isn't just to, you know, see what happens
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when things get super hot. The mission of this
0:43
deep dive is to explore why scientists are using
0:46
this machine to do something that sounds almost
0:49
like ancient mythology. They're trying to recreate
0:52
the first microscopic fractions of a second right
0:55
after the Big Bang. Exactly. I mean, we are talking
0:58
about the largest, arguably the most complex
1:00
machine our species has ever engineered. The
1:03
Large Hadron Collider. operated by CERN. The
1:06
LHC. Right, the LHC. And what it does is it takes
1:09
the absolute smallest pieces of matter, accelerates
1:12
them to 99 .9999999 % of the speed of light,
1:16
and then deliberately crashes them head -on.
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Just smashing them together at unbelievable speeds.
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Smashing them together, yeah. And the motivation
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driving all of this extreme engineering is a
1:26
quest to answer really the oldest question we
1:28
have, which is, what is the universe actually
1:31
made of? Which is such a massive question. So,
1:34
okay, let's unpack this a bit, because if you
1:36
were listening to this, you might be wondering
1:37
why thousands of physicists and billions of dollars
1:40
are poured into an underground freezer just to
1:43
smash things. We first have to clarify what it
1:46
is we are actually smashing. Right, the ingredients.
1:48
Yeah. So the name Large Hadron Collider kind
1:51
of gives us the first clue. A hadron is basically
1:53
a composite particle, and the specific ones they
1:56
use most often are protons. Protons, yes. The
1:59
workhorses of the collider. Right. And you don't
2:01
need a background in quantum physics to know
2:03
what a proton is. They're the basic building
2:06
blocks sitting in the center of every single
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atom, including the ones making up the device
2:11
you're listening to this on right now. Exactly.
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What's fascinating here is that by choosing protons,
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scientists are deliberately choosing a very messy
2:21
collision. Messy how? Like they aren't just solid
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little spheres. No, not at all. A proton is not
2:27
a solid uniform ball. It is essentially a tiny
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chaotic bag of even smaller particles called
2:34
quarks. And those are held together by these
2:36
things called gluons. Okay, so it's a bag of
2:38
smaller stuff. Right. So when you throw two of
2:41
these composite bags at each other at almost
2:42
the speed of light, you're guaranteeing an incredibly
2:45
violent, incredibly complex interaction. You
2:47
aren't just, you know, bumping two billiard balls
2:50
together. You're initiating this chaos. catastrophic
2:52
disruption of matter. Exactly. A fundamental
2:55
disruption. And that disruption brings us to
2:57
the core mechanism of the whole project, which
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hinges on Einstein's famous equation, E equals
3:04
MC squared. The most famous equation in the world.
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Right. And that equation basically tells us that
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energy and mass, they aren't two separate things.
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They are two forms of the same exact thing. Right.
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They can be converted back and forth. Yeah. So
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this collider, it isn't just a giant sledgehammer
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trying to crack open a proton to see what's inside.
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It is quite literally an engine of creation.
3:25
Yes. And that distinction is crucial. It completely
3:28
changes how we view the machine. Because when
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those two protons collide, an astonishing amount
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of kinetic energy, which is just the energy of
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motion, is suddenly concentrated into this tiny
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microscopic point in space. Just a massive amount
3:43
of raw energy in one spot. Right. And because
3:45
of the rules governing our universe, that concentrated
3:48
energy doesn't simply vanish. It has to go somewhere
3:51
or rather it has to become something. OK, so
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I was thinking about how to explain this. And
3:55
it's kind of like imagine crashing two perfectly
3:58
normal sedans together at top speed. OK, I like
4:01
where this is going. Right. But instead of just
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getting crumpled car parts and glass everywhere,
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the energy of the crash is so intense that a
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brand new glowing spaceship just pops out of
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the explosion. That is a brilliant analogy, actually,
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because normally. If you strike an anvil with
4:15
a hammer, the kinetic energy from your swing
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just dissipates. Yeah. Right. It becomes a loud
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noise and a little bit of heat. Right. Just bleeds
4:23
off into the room. But inside the LHC, there
4:25
is so much kinetic energy focused into such a
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tiny localized point that it can't just dissipate
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as heat. Instead, that raw energy. literally
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freezes into entirely new physical matter. It
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conjures it out of nowhere. It conjures brand
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new exotic particles into existence that absolutely
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were not there before the impact. That is just
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wild to me. It's essentially magic, but it's
4:50
physics. It really is. And these particles generated
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from that raw energy, they are highly unstable.
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They're incredibly heavy, and they are definitely
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not the kind of matter you find just floating
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around in the modern universe today. Right, because
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these are the original ingredients of the cosmos,
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right? Exactly. By generating these particles,
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scientists are basically rolling back the clock.
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You see, as the universe expanded over billions
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of years, it cooled down. And those heavy early
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particles, they decayed into the stable, boring
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matter we see today. The stuff that makes up
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us and the planet. Right. So if you want to study
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the original fabric of reality, you have to build
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a machine capable of baking those original ingredients
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all over again. Okay, but here's where it gets
5:34
really interesting. Because to recreate those
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primordial Big Bang conditions, you can't just
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set up like a... a standard laboratory laser
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on a desk, you need a machine that creates conditions
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more extreme than almost anywhere else in nature.
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The engineering constraints are just mind -boggling.
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They really are. Like, for starters, you have
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to condense these protons into a beam that is
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thinner than a single human hair. Thinner than
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a hair, yeah. And it's actually two beams traveling
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in opposite directions around that 27 -kilometer
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track. And they are circling millions of times
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every single second. Millions of times a second.
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Keeping a hair -thin beam of particles perfectly
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on track at that speed just sounds impossible.
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I mean, you can't just build a metal tube for
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them to travel through, right? Because they would
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just instantly drift and smash into the walls.
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Right. Any physical contact and the beam is lost.
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You have to steer them without touching them
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at all. So how do you wrangle moving charged
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particles? Without touching them. Magnets. It's
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the only way. Thousands of massive, incredibly
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powerful magnets line the entire perimeter of
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the tunnel. And their whole job is to constantly
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push, pull, and focus those protons, guiding
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them perfectly along the curve of that underground
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track. Okay, but the faster the protons move,
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the stronger the magnetic field needs to be to
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keep them from just flying off in a straight
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line, right? Exactly. And to bend a beam moving
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at 99 .9999999 % the speed of light, standard
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magnets aren't going to cut it. You need a magnetic
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field so intense that if you tried to run the
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necessary electrical current through, say, standard
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copper wire. It would just melt. Oh, instantly.
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The electrical resistance would generate enough
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heat to vaporize the wires and probably a good
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chunk of the machine along with them. Wow. So
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they use superconducting magnets. Yes. Superconductivity
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is this incredible state where a material conducts
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electricity with absolutely zero resistance.
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No friction, no heat, just a perfect unimpeded
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flow of energy. But the catch is materials only
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achieve that superconducting state under extremely
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specific freezing conditions, right? Very freezing.
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The entire magnetic ring is encased in a cooling
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system that pumps thousands of liters of liquid
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helium around the wiring. This drops the temperature
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of the magnets down to 1 .9 Kelvin. Which is
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just a fraction of a degree above absolute zero.
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Exactly. The theoretical limit of coldness in
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the universe where all atomic movement basically
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stops. See, that juxtaposition is what blows
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my mind. You have these localized collision points
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inside the machine generating temperatures hundreds
8:02
of thousands of times hotter than the center
8:04
of the sun. And those microscopic infernos are
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surrounded by magnets chilled colder than the
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void of deep space. And that extreme cold is
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the absolute fundamental prerequisite. for controlling
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the extreme heat it's a delicate balance if a
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magnet warms up by even a single degree it undergoes
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this process called a quench a quench what happens
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then it loses its superconductivity resistance
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returns instantly the heat spikes and the massive
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magnetic field just collapses the beam would
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be lost in a fraction of a second That's terrifying.
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The precision required to maintain that environmental
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balance across a 27 -kilometer ring is just a
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monumental achievement. It really is one of humanity's
8:46
greatest engineering feats. So all of this precision,
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the hair -thin beams, the liquid helium, the
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crazy electrical currents, it's all orchestrated
8:54
to force these two beams to cross paths and collide
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head -on at specific points. Right, at a handful
9:00
of very specific points around the track where
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we have detectors waiting. And calling them detectors
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feels like a massive understatement. Subterranean
9:07
structures the size of cathedrals, right? Just
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packed with layers of sensors. Cathedral -sized
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is accurate. They are gargantuan digital cameras,
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essentially. Okay, but when the beams cross and
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that energy freezes into new exotic particles,
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how do these giant cameras actually see anything?
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Because the new matter doesn't just hang around
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to pose for a picture. Right. It decays almost
9:31
instantly. Right. It falls apart incredibly fast.
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So they don't actually look for the exotic particles
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directly. They look for the shrapnel. The shrapnel.
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Yeah. As those heavy, short -lived particles
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decay, they explode into a cascade of lighter,
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more stable particles that blast outward through
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the layers of the detector. And the detectors
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build kind of like an onion. Okay. Layers of
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sensors. Exactly. The innermost layers are silicon.
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tracking the electrical charge of the passing
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particles. Outer layers measure the energy absorbed
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as the particles are stopped. So it's essentially
10:01
forensic reconstruction. By looking at the speed
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and the trajectory of all that microscopic shrapnel,
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they use supercomputers to trace the lines backward
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to the exact point of impact. Bingo. They calculate
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the mass and properties of whatever materialized
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in that one millionth of a second before it exploded.
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That is unbelievable. And this forensic capability,
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this is what the whole physics community spent
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decades preparing for, right? Because they had
10:26
a very specific target in mind. They did. It
10:29
was a massive, decades -long treasure hunt that
10:32
culminated in 2012 with the discovery of the
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Higgs boson. The famous God particle, though
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I know physicists hate that name. They really
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do despise that name, yes. But if you're wondering
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why they spent billions hunting for this one
10:45
specific particle, it comes down to a glaring
10:48
hole in our basic understanding of reality. Right,
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the standard model. Yeah, the standard model,
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which is basically the instruction manual for
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all the fundamental particles and forces in the
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universe. But for a very long time, this manual
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was missing a really crucial chapter. It was.
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The math of the... Standard Model was incredibly
11:06
accurate at describing how particles behave,
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but it couldn't explain one fundamental property,
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and that property is mass. Why things weigh anything
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at all. Exactly. The equations couldn't answer
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why a quark inside a proton is heavy, while a
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photon, which is a particle of light, has absolutely
11:25
zero mass and just zips around at the speed limit
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of the universe. If everything is just a fundamental
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particle, why do some have weight while others
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don't? Right. So nearly half a century before
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the LHC was even built, theorists came up with
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this radical idea. They suggested that the universe
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isn't just empty space. They theorized that everywhere,
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in every corner of the cosmos, there is this
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invisible, undetectable field permeating all
11:50
of reality. The Higgs field. Right. And to visualize
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how this invisible field actually gives things
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mass, let's use an analogy. Imagine moving through
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water. Okay. Like wading through a swimming pool.
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Yeah. If you were trying to walk through waist
12:03
-deep water, you have to push through it. The
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water drags on you. It slows you down. It makes
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you feel heavy and sluggish. It takes effort
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to move. Exactly. But if you compare that to
12:11
moving through the air, you don't feel that drag.
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You just move freely. So the drag in that scenario
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is how we can conceptualize mass. Precisely.
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The theory proposed that particles gain their
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mass solely based on how much they interact with
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this invisible Higgs field. A heavy particle
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interacts with the field deeply, so it feels
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a massive amount of drag, like walking through
12:35
water. Okay, and a particle of light. The photon
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doesn't interact with the field at all. It feels
12:40
no drag, like moving through empty air. And therefore,
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it has absolutely no mass. It just coasts right
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through. That is a brilliantly elegant theory.
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But I mean, in science, an elegant idea isn't
12:50
enough, right? You have to actually prove it.
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You do. And the problem is you can't see this
12:55
field. You can't measure it directly with a thermometer
12:58
or a ruler. Right. It's totally invisible water.
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But the mathematics offered one testable prediction.
13:03
Yes. The prediction was that if you hit this
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invisible field with enough concentrated energy,
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it would ripple. And if you jostle the field
13:11
hard enough, that localized vibration would actually
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manifest as a distinct particle. And that particle
13:17
is the Higgs boson. That's the one. So let me
13:20
make sure I have this straight. We couldn't see
13:23
the water of the universe directly. But by smashing
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protons together at near light speed, we basically
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made a massive splash. And that splash is the
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Higgs boson. That is a fantastic way to put it.
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Yes, we forced the field to reveal itself by
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making a splash. And the stakes here were monumental.
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Because if they didn't find it... If the machine
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ran at full power for years and failed to produce
13:47
the Higgs boson, it would indicate that our entire
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foundational framework for how reality operates
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was deeply, fundamentally flawed. Decades of
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physics would just have to go straight back to
13:58
the drawing board. Talk about pressure. But in
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2012, after sifting through the shrapnel of hundreds
14:04
of trillions of individual collisions, Two of
14:07
those cathedral -sized detectors spotted the
14:09
signature. And they were operating completely
14:11
independently, too, to ensure they didn't bias
14:13
each other's results. Right, which makes it even
14:15
more incredible. They both found the exact same
14:16
ripple. They proved the Higgs field is real.
14:19
It was an absolute triumph. It finalized the
14:22
standard model and, of course, earned a Nobel
14:25
Prize for the theorists who had predicted it
14:27
50 years prior. Now, finding that ultimate missing
14:30
puzzle piece might sound like the end of the
14:32
story. You might assume the physicists just,
14:35
you know, packed up their superconducting magnets
14:37
and went home. Far from it. Right. Because finding
14:40
the Higgs actually highlighted just how much
14:42
of the universe we still do not understand. I
14:45
mean, the standard model might be finished, but
14:48
it leaves out some truly massive elements of
14:50
reality. The most glaring omission being dark
14:53
matter. Astronomical observations show us that
14:57
there is this mysterious, invisible substance
14:59
out in the cosmos that outweighs all the ordinary
15:03
visible matter, the stars, the planets, us, by
15:06
a staggering margin. And the standard model has
15:09
no particle that accounts for it. It's just entirely
15:11
missing from the math. Completely. Furthermore,
15:14
the model totally fails to incorporate gravity,
15:16
which is literally the most ubiquitous force
15:19
we experience every single day. So that's why
15:21
the collider didn't shut down after 2012. Scientists
15:23
are continually upgrading it, cranking up the
15:26
energy levels, looking for entirely new particles
15:28
that could explain dark matter or bridge that
15:32
gap with gravity. Exactly. They are actively
15:35
looking for cracks in their own theory. But so
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far, nature's been pretty stubborn, right? No
15:40
new surprises have really popped up. It is stubborn,
15:42
yes. Despite the higher energy collisions, no
15:46
wild new particles or physics -breaking surprises
15:48
have materialized. The standard model is holding
15:51
its ground flawlessly. Which, you know, to an
15:54
outsider, running a multi -billion dollar machine
15:56
and finding nothing new sounds kind of like a
15:58
failure. I get why people think that, but in
16:01
particle physics, a null result is actually a
16:03
profound result. Really? How so? Because the
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stubbornness of nature provides essential boundary
16:09
conditions. By meticulously proving that new
16:11
particles do not exist at these specific energy
16:13
levels, the collider systematically narrows down
16:16
the hiding places for new physics. Ah, okay,
16:19
so it tells you where not to look. Exactly. It
16:21
forces theorists to abandon dead -end ideas and
16:24
invent entirely new mathematical approaches.
16:27
That makes sense. Though, you know... pushing
16:29
the boundaries of known physics to hunt for unknown
16:31
forces it understandably causes some unease for
16:35
people who aren't quantum physicists which we
16:38
have to talk about this brings us to the public
16:41
panic from the late 2000s right before the machine
16:44
powered on oh the doomsday scenarios yeah i remember
16:48
this so clearly there were lawsuits protests
16:50
major news headlines claiming the lhc was going
16:54
to trigger the end of the world the primary fear
16:56
was that focusing that much energy into a microscopic
16:59
point could accidentally generate a miniature
17:01
black hole. Right. And the narrative was that
17:04
this tiny black hole would just sink to the Earth's
17:06
core and swallow the planet from the inside out.
17:09
Which, I mean, even if you like science, the
17:12
phrase manufacturing a black hole underground
17:14
is definitely going to trigger some primal anxiety.
17:17
It sounds alarming. Absolutely. So how do you
17:19
definitively put the listener's mind at ease?
17:21
How do we know this machine won't just end the
17:23
world tomorrow? We just point to the sky, really.
17:27
The debunking of that whole scenario relies on
17:29
cosmic rays. You see, our universe is constantly
17:32
operating as a giant naturally occurring particle
17:35
accelerator. Just constantly smashing things
17:37
together on its own. Exactly. For four and a
17:40
half billion years, high energy particles from
17:43
exploding stars and active galaxies have been
17:46
slamming into the molecules of Earth's upper
17:48
atmosphere. And those natural collisions happening
17:50
above our heads, they are occurring at energy
17:53
levels far exceeding anything we could ever generate
17:56
inside the collider, right? Far exceeding it,
17:58
yes. Nature has been running this exact same
18:01
high -energy collision experiment billions of
18:03
times a second for the entire history of the
18:05
solar system. And our planet remains firmly unswallowed
18:09
by black holes. Still here. Still here. The collider
18:12
isn't doing anything unnatural. It is merely
18:14
recreating these naturally occurring atmospheric
18:17
collisions in a highly controlled underground
18:20
environment where we happen to have specialized
18:22
digital cameras waiting to record the aftermath.
18:25
That is so reassuring to hear spelled out like
18:28
that. But, you know, looking past the microscopic
18:30
physics and the debunked black hole panics, there
18:33
is an entirely different reason to marvel at
18:36
this collider. And it has to do with the species
18:38
that actually built it. The human element. Yeah.
18:41
We are talking about a laboratory design constructed
18:44
and operated by thousands of scientists, engineers,
18:48
and technicians. from dozens of different nations
18:51
around the globe. It operates continuously across
18:53
geopolitical borders, across language barriers
18:56
and deep cultural divides. And what I find so
18:58
exceptional about it is the complete lack of
19:01
a conventional payoff. There's no military application
19:04
for a Higgs boson. No, you can't weaponize the
19:06
fundamental laws of mass. Right. And there's
19:08
no commercial product to patent and sell to consumers.
19:11
The absolute only reason all these rival nations
19:14
pooled their massive budgets and their brightest
19:16
minds is just this collective desire. to understand
19:20
nature, to satisfy human curiosity. And that
19:23
collaborative effort, it extends way beyond the
19:26
physical tunnel in Switzerland. This raises an
19:29
important point about the data itself. When the
19:31
beams are crossing, there are up to a billion
19:34
individual proton collisions happening every
19:37
single second. A billion a second? Yes. And the
19:41
sensors produce a torrent of raw data that would
19:44
fill thousands of commercial hard drives every
19:47
single day. No single supercomputing facility
19:49
on Earth could possibly process or store that
19:53
much information. So how do they even sift through
19:55
all that noise to find the shrapnel of something
19:57
like a Higgs boson? They built a decentralized
20:00
global infrastructure. It's called a worldwide
20:02
LHC computing grid. The data from the detectors
20:06
in Europe is instantly beamed out to a tiered
20:09
network of over 170 computing centers located
20:12
in more than 40 countries. Oh, wow. So it's a
20:14
massive distributed network. Exactly. Institutions
20:17
from all around the world take fragments of the
20:19
data, crunching the complex mathematics collectively.
20:21
That is just beautiful. It proves that human
20:24
knowledge scales exponentially when we actually
20:26
choose collaboration over competition. In an
20:29
era where so much of the modern world just feels
20:31
hopelessly fractured, you have tens of thousands
20:34
of people seamlessly sharing petabytes of data
20:37
purely for the sake of discovery. Knowledge really
20:41
is most valuable when we collaborate. The LHC
20:43
stands as a monument to what humanity can accomplish
20:46
when we unite behind a shared question. It really
20:49
does. So to recap the scope of what we've explored
20:52
today, we started with a 27 kilometer cryogenic
20:55
ring buried deep underground, navigating the
20:58
absolute extremes of cold and the blazing heat
21:01
of the early cosmos. We looked at how kinetic
21:03
energy crystallizes into brand new matter. Right.
21:06
Tracking that microscopic shrapnel to finally
21:08
prove the existence of an invisible field, the
21:11
water of the universe that gives everything its
21:13
mass. And we saw how a global network of humans
21:16
works in pure harmony to process. the secrets
21:18
hidden inside a single proton. All of this to
21:21
answer one simple question. What is the world
21:23
made of? It is the ultimate refusal to stop asking
21:26
what lies one level deeper. Which leaves us with
21:29
a final thought for you to mull over. The collider
21:32
is still running. It's still hunting for that
21:35
invisible dark matter holding our galaxies together,
21:38
still searching for the missing pieces of gravity.
21:41
But let's imagine a future where the machine
21:43
succeeds completely. Okay. let's say we finally
21:46
complete the standard model we find the dark
21:49
matter particles and we map out the absolute
21:51
final laws of physics will that actually be the
21:54
end of the scientific journey or by cracking
21:57
those ultimate mysteries will we simply realize
21:59
that our grand finished puzzle is really just
22:02
one tiny corner of an even larger entirely different
22:05
game we haven't even begun to conceive of yet
22:08
Given the history of science, there's almost
22:10
certainly a deeper layer waiting to be found.
22:12
Always another layer. Thank you for joining us
22:15
on this deep dive into the absolute limits of
22:17
human engineering and cosmic knowledge. We'll
22:19
leave you to think about that invisible field
22:21
giving weight to the world all around you. Until
22:23
next time.