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Superconductors – Electricity Without Resistance · Talking Science

0:00
Welcome to today's deep dive. I'm really glad
0:03
you could join us today because our mission is,
0:05
well, it's to explore something in physics that
0:08
sounds honestly like literal magic. It really
0:11
does. It sounds completely made up. Right. But
0:13
it's actually one of the most striking and frankly
0:16
useful discoveries of our time. We're talking
0:19
about superconductors. Which is just a massive
0:22
topic. It is, yeah. But to start, I want you
0:24
to picture yourself in a grocery store parking
0:27
lot. You grab the handle of your shopping trolley.
0:31
You line it up and you give it a really good
0:33
hard push across the asphalt. And I mean, we
0:36
all know exactly how that ends. Right. Rattles
0:38
forward for like a few feet, it slows down and
0:41
then it just clunks to a stop. Exactly. But I
0:44
want you to imagine a scenario where it doesn't
0:46
do that. You give that trolley a single push
0:48
and instead of scraping to a halt, it just keeps
0:50
rolling. Oh, wow. Just forever. Forever. It rolls
0:53
out of the parking lot, down the street, across
0:55
the whole city, and it never, ever slows down.
0:58
There's just absolutely zero friction. It coasts
1:02
for eternity on that initial burst of energy.
1:04
Which, obviously, in our everyday mechanical
1:06
world is just completely impossible. Yeah, friction
1:09
always wins in the real world. Always. But, so
1:12
we're looking into a phenomenon today where,
1:15
in the world of electricity, there is actually
1:17
a way to cheat friction entirely. Yeah, and it's...
1:21
One of the most astonishing behaviors in all
1:23
of physics, honestly. Under very specific conditions,
1:28
certain materials can carry an electric current
1:31
with zero resistance. Zero. Zero. Like you could
1:35
start a current flowing in a loop of this material
1:37
and it would theoretically just flow round and
1:39
round for millions of years without ever losing
1:42
even a fraction of its energy. Which is just
1:44
wild to think about. And these are called superconductors.
1:46
Exactly. Superconductors. OK, let's unpack this
1:49
because. If we are going to understand just how
1:53
monumental a zero resistance material is, we
1:56
first have to understand the invisible toll that
1:58
regular resistance takes on our world every single
2:01
day. Yeah, the tax we constantly pay. Right.
2:03
So I like to picture just ordinary copper wiring,
2:07
like the stuff running through the walls of your
2:09
house right now. Electricity is, at its most
2:13
basic level, just a flow of... Tiny, negatively
2:16
charged particles, which are electrons, moving
2:19
through that wire. And, you know, the mental
2:22
image most people have is that those electrons
2:24
are cruising down an empty, open highway. Like
2:27
a water pipe or something. Yeah, exactly. Like
2:29
water in an empty pipe. But the reality at the
2:32
microscopic level is... well, it's much more
2:35
chaotic, that copper wire is made of this dense
2:38
lattice of atoms. So it's less like an open highway
2:41
and more like trying to sprint through a really
2:44
dense jostling crowd. That's a perfect way to
2:46
put it. The wire is essentially an obstacle course.
2:49
As these tiny electrons try to move forward,
2:52
they just keep crashing into the copper atoms.
2:54
Right. And the problem is compounded, I guess,
2:56
because those copper atoms aren't even standing
2:58
perfectly still, are they? No, not at all. They
3:00
possess thermal energy. which means they're constantly
3:03
vibrating in place. Because they have heat. Right.
3:06
And the warmer the wire is, the more aggressively
3:08
those atoms vibrate, which creates an even more
3:11
chaotic environment for the electrons trying
3:13
to pass through. And every single one of those
3:16
microscopic crashes has a consequence, right?
3:18
Like something has to give. It does. When an
3:20
electron collides with one of these vibrating
3:23
atoms, it transfers a little bit of its kinetic
3:25
energy to that atom. Okay. And that actually
3:27
causes the atom to vibrate even harder. So in
3:30
our macro world, we experience those intense
3:33
atomic vibrations as heat. Oh, interesting. Yeah,
3:37
this is the mechanism of electrical resistance.
3:39
It is literally the electrical equivalent of
3:41
friction, constantly sapping energy from the
3:43
current and bleeding it away as heat. Which totally
3:46
explains why, like, the glowing metal coils inside
3:49
a space heater or an old toaster get so intensely
3:53
hot. Exactly. That is electrical resistance working
3:56
by design. Yeah. We actually want those billions
3:59
of electron collisions to generate heat in that
4:01
case. Right. I want my toast to get toasted.
4:03
Right. But most of the time, we absolutely do
4:06
not want that heat. I mean, think about the global
4:08
power grid. When a power station generates electricity,
4:11
it has to send that current across hundreds of
4:14
miles of transmission lines just to reach a city.
4:17
And because of electrical resistance? Because
4:19
of resistance, yeah. A highly meaningful fraction
4:21
of all the electricity humanity generates is
4:23
simply lost in transit. That's incredibly frustrating.
4:26
It's massive. It just dissipates into the air
4:28
as waste heat before it ever even reaches your
4:30
light switch. So it really is like an unavoidable
4:33
universal tax. Resistance is just this tax we
4:36
pay on every single flow of current everywhere
4:38
on Earth. Until we introduce a superconductor.
4:41
OK, here we go. Because a superconductor doesn't
4:43
just lower that tax. It abolishes it completely.
4:47
And this is where the physics starts to sound
4:49
like literal magic to me. How can you possibly
4:52
abolish an unavoidable tax? Well, to understand
4:55
that, we have to go back to 1911. OK. To a Dutch
4:58
physicist. named Heike Kammerling -Owens. And
5:02
funny enough, he wasn't actually looking for
5:04
superconductors at all. What was he looking for?
5:06
He was just obsessed with extreme cold. He had
5:09
recently figured out how to liquefy helium, which
5:12
that allowed him to cool materials down closer
5:16
to absolute zero than anyone ever had before.
5:18
Wait, let's define absolute zero real quick.
5:20
That being the theoretical point where all thermal
5:22
energy is just gone, right? Yes. The temperature
5:24
where atoms literally stop vibrating entirely.
5:27
Exactly. It's roughly minus 273 degrees Celsius.
5:31
Literally the coldest temperature physically
5:33
possible in the universe. That is just incomprehensibly
5:36
cold. It really is. So, Oswald was cooling a
5:39
wire made of solid mercury down to within just
5:42
a few degrees of absolute zero. He just wanted
5:44
to see how its electrical resistance would behave.
5:46
OK. And what was the expectation there? That
5:50
as the mercury cooled and its atoms stopped vibrating
5:52
so aggressively, the resistance would just smoothly
5:55
and gradually decline. Right. Because going back
5:58
to your analogy, the jostling crowd is calming
6:01
down. So the electrons should have a much easier
6:03
time getting through. That was the logical assumption.
6:06
Yeah. But that isn't what happened. No. At a
6:09
very specific threshold, about four degrees above
6:12
absolute zero. The electrical resistance of the
6:16
mercury didn't just decline, it vanished instantly.
6:19
Like completely. It dropped to exactly zero.
6:22
Not some microscopic fraction like 0 .0001, exactly
6:27
zero. Exactly zero. The entire scientific community
6:30
was stunned. I mean, it actually took decades
6:33
and the development of the entirely new field
6:35
of quantum mechanics for physicists to finally
6:38
explain how the electrons were getting through
6:40
that lattice without a single collision. Because
6:42
it defies all common sense. I mean, even if the
6:45
atoms are practically frozen in place, they are
6:47
still physically sitting there in the wire. They're
6:49
still physical obstacles. So how do the electrons
6:52
avoid hitting them? Well, what's fascinating
6:54
here is that the electrons fundamentally change
6:57
how they behave. What do you mean? In an ordinary
7:00
copper wire at room temperature, electrons are
7:02
these independent, chaotic individuals. They
7:05
constantly repel each other because they all
7:07
have negative charges. Right, like magnets pushing
7:09
away from each other. Exactly. But when you cool
7:12
certain materials below their critical temperature,
7:15
something bizarre happens. The electrons pair
7:18
up. We call these Cooper pairs. Wait, wait, wait.
7:21
How does being freezing cold suddenly make chaotic
7:24
electrons agree to march in perfect lockstep?
7:27
If two negative electrons naturally repel each
7:29
other, what unseen force is suddenly binding
7:32
them together? It's actually the lattice of atoms
7:35
itself doing the binding. Really? Yeah. Picture
7:37
a heavy bowling ball rolling across a soft mattress.
7:40
Okay, I'm picturing it. As it rolls, it presses
7:42
down, right? Yeah. It creates a depression in
7:45
the mattress. Now, if another bowling ball is
7:47
nearby... it will naturally roll into that depression.
7:50
Right. It kind of falls into the gravity well.
7:52
That makes perfect sense visually. So in a superconductor,
7:56
an electron moves through the lattice of positively
7:58
charged atoms. Because the electron is negative,
8:01
it pulls the positive atoms slightly inward toward
8:05
itself as it passes by. Oh, I see. This creates
8:07
a tiny temporary area of concentrated positive
8:11
charge, like a microscopic depression in the
8:14
lattice. A second electron is intensely attracted
8:17
to that concentrated positive pocket, and it
8:20
gets pulled in right behind the first one. So
8:22
even though they technically hate each other,
8:24
the way they warp the environment around them
8:26
forces them into a couple? Exactly. And by forming
8:30
these Cooper pairs, they unlock a purely quantum
8:33
mechanical effect. All the countless millions
8:35
of Cooper pairs in the material synchronize.
8:37
They sync up. Yeah, they stop acting as individual
8:40
particles bouncing around and they merge into
8:42
a single unified quantum state. Going back to
8:46
our crowd analogy earlier, it's like a chaotic
8:49
mob of people suddenly grabbing a partner, organizing
8:52
into a synchronized marching band, and moving
8:55
through the hallway in perfect lockstep rhythm.
8:57
That is a brilliant way to visualize it. Yes.
8:59
Because they are moving as a single coordinated
9:02
quantum wave, they just glide. through the lattice
9:04
in perfect harmony with the structure of the
9:06
atoms. That is amazing. No individual electron
9:09
can accidentally veer off and crash into an atom.
9:12
And, as we know, no crashes mean no lost energy.
9:16
Resistance drops to zero. That is just mind -bending.
9:20
The individual particles couldn't survive the
9:22
obstacle course on their own, but by pairing
9:24
up and moving collectively, they literally rewrite
9:27
the rules of movement. It really is one of the
9:30
most elegant demonstrations that when you assemble
9:33
enough particles under the right conditions,
9:35
the collective behaves in ways the individual
9:38
never could. Wow. Now, zero electrical resistance
9:41
is a world -changing property all on its own.
9:44
But superconductors actually have a second major
9:47
capability, right? They do, yes. And it is incredibly
9:50
visual. Honestly, if you look up videos of it,
9:52
it looks like a special effect from a science
9:54
fiction movie. You're talking about the expulsion
9:56
of magnetic fields? known as the Meissner effect.
9:59
Yes, the Meissner effect. Let me paint a picture
10:02
of this for you if you haven't seen it. If you
10:04
take a chunk of superconducting material and
10:06
you drop it in a bath of liquid helium so it
10:09
gets freezing cold. So it hits that zero resistance
10:11
state. Right. And then you take a regular, everyday
10:14
magnet and drop it on top of it. The magnet won't
10:17
touch the material. No, it won't. It just stops
10:19
in midair. It just hovers there, floating on
10:22
an invisible cushion. You can even tap it, and
10:24
it will spin frictionlessly in thin air. It is
10:27
wild to watch. It looks exactly like anti -gravity,
10:31
but the underlying mechanism is pure electromagnetism.
10:34
How does it work? Well, when you bring a magnet
10:36
near a superconductor, the magnetic field tries
10:39
to penetrate the material. But the superconductor
10:42
responds by spontaneously generating these microscopic
10:46
frictionless electric currents all along its
10:49
surface. And because it has zero resistance,
10:52
those surface currents can just spin up effortlessly,
10:54
right? There's nothing holding them back. Exactly.
10:56
And any electric current generates a magnetic
10:59
field. So the surface currents on the superconductor
11:01
create a magnetic field that perfectly mirrors
11:04
and opposes the field of the external magnet.
11:07
Oh, I see. It pushes back with the exact same
11:09
amount of force causing the magnet to levitate.
11:12
But the really crazy part is... When the magnet
11:15
isn't just hovering but gets locked in place.
11:17
I've seen demonstrations where you can turn the
11:19
superconductor entirely upside down and the levitating
11:22
magnet doesn't fall. No, it stays right there.
11:25
Stay suspended underneath it, pinned in three
11:27
-dimensional space. That happens because, well,
11:30
most superconductors aren't entirely perfect,
11:33
right? They have microscopic impurities in their
11:36
structure. Okay. So instead of repelling 100
11:38
% of the magnetic field, tiny... thread -like
11:42
strands of the magnetic field manage to pierce
11:45
through these imperfections. Like little needles
11:47
of magnetism. Yeah, we call them flux tubes.
11:50
The superconductor essentially grabs onto these
11:52
penetrating threads of magnetism and refuses
11:55
to let them move. It literally locks the magnet
11:57
at that exact distance and angle. So what does
11:59
this all mean for us? I mean, a hovering quantum
12:02
-locked magnet is an incredible party trick for
12:05
a physics lab. But how are we actually using
12:08
this outside the lab? Well, the most famous application
12:11
you might have heard of is maglev trains magnetic
12:13
levitation. By building a track lined with electromagnets
12:18
and putting superconducting magnets on the train,
12:20
you can lift an entire passenger train off the
12:23
rails. It just floats a few inches in the air.
12:26
Meaning there are no wheels grinding on steel
12:28
rails, zero mechanical friction whatsoever. Which
12:32
removes almost all the wear and tear that usually
12:34
plagues traditional rail systems, while allowing
12:37
the trains to safely glide at. like hundreds
12:40
of miles an hour. That's incredible. But the
12:42
applications go far deeper into everyday life.
12:45
Like, if you have ever undergone an MRI scan
12:48
at a hospital, you've relied on a superconductor.
12:51
Wait, really? Inside the scanner itself? Yeah,
12:53
inside the scanner. To see inside the human body
12:56
with that level of clarity, an MRI needs a massive,
12:59
incredibly stable magnetic field. Generating
13:03
a magnetic field that powerful requires a colossal
13:06
amount of electric current. If you tried to push
13:09
that much current through ordinary copper wires,
13:11
the electrical resistance would generate a lethal
13:13
amount of heat. Oh, because of all the collisions
13:15
we talked about. Exactly. The machine would literally
13:18
melt itself from the inside out. So they use
13:20
a coil of superconducting wire instead. Precisely.
13:23
They use liquid helium to keep the coil near
13:26
absolute zero. Once the current is flowing through
13:30
that superconducting loop, it just circulates
13:32
continuously with zero resistance, zero heat,
13:36
and zero energy loss. And that creates a perfect,
13:39
unwavering magnetic field to scan the patient.
13:42
That immediately changes the perspective, honestly,
13:45
because this isn't just theoretical physics.
13:46
This is a working tool saving lives in hospitals
13:49
every single day. It really is. And it scales
13:52
up to the absolute limits of human engineering,
13:54
too. The Large Hadron Collider at CERN, you know.
13:57
the massive particle accelerator spanning the
14:00
border of France and Switzerland that runs on
14:02
this principle too. Without superconductors,
14:04
the Large Hadron Collider literally could not
14:06
exist. They used thousands of massive superconducting
14:10
electromagnets to steer beams of protons around
14:12
a 17 -mile ring at nearly the speed of light.
14:15
Unbelievable. They also used them to contain
14:17
the superheated plasma in experimental nuclear
14:19
fusion reactors. These are the tools that are
14:22
driving the next century of innovation. Which,
14:25
I mean, brings up a very obvious question. If
14:27
this technology is so miraculous, if it can power
14:30
MRIs, float trains, and carry endless electrical
14:33
currents without wasting a single drop of energy
14:35
to heat, Why aren't the power lines outside my
14:39
house made of superconductors? Why are we still
14:41
losing massive amounts of energy on our grids?
14:43
You've hit on the greatest bottleneck in modern
14:45
material science. What's the catch? The catch
14:47
is the cold. For decades after Arno Wynn's discovery,
14:51
superconductivity was only found at temperatures
14:53
near absolute zero. And building an MRI machine
14:57
that requires liquid helium is one thing, but
14:59
keeping hundreds of miles of neighborhood power
15:02
lines chilled to minus 270 degrees Celsius is,
15:05
well, impossible. It's totally impossible. Liquid
15:08
helium is incredibly expensive, it's difficult
15:10
to handle, and it's super prone to boiling away.
15:12
It simply doesn't scale to global infrastructure.
15:15
However, the paradigm shifted drastically in
15:18
the late 1980s. Scientists discovered this bizarre
15:21
class of ceramic materials called cuprates that
15:24
achieved... superconductivity at much higher
15:26
temperatures. And I think we need to put higher
15:29
in massive quotation marks here, just for context.
15:32
Very true, yeah. These ceramics became superconductors
15:35
at around minus 195 degrees Celsius. Which is
15:39
still freezing. To a human being, that is still
15:42
lethally, instantly freezing. But to an engineer,
15:45
it was a revolution. Because minus 195 degrees
15:49
Celsius happens to be the boiling point of liquid
15:51
nitrogen. Exactly. which changed the economics
15:54
of the field overnight. Liquid nitrogen is super
15:57
cheap to manufacture. It's actually often described
16:00
as being cheaper than milk. Really? Cheaper than
16:02
milk? Yeah. And it's far easier to handle than
16:05
liquid helium. Discovering materials that could
16:08
be cooled by liquid nitrogen was such a colossal
16:11
leap toward practical applications that the researchers
16:14
were awarded a Nobel Prize almost immediately.
16:17
But even liquid nitrogen requires heavy insulation
16:19
and constant cooling systems, right? You can't
16:21
just leave it out. Right. Which brings us to
16:24
the ultimate prize, the holy grail of physics
16:27
and material science, a room temperature ambient
16:30
pressure superconductor. A material you could
16:32
hold in the palm of your hand, sitting in a normal
16:35
room at normal atmospheric pressure that carries
16:38
electricity with absolutely zero resistance.
16:42
No cooling jackets, no liquid nitrogen required.
16:45
Here's where it gets really interesting, though.
16:47
Because if you pay attention to science news,
16:49
every few years the Internet just explodes with
16:53
a viral headline. Oh, yeah. A lab somewhere claims
16:56
they've finally done it. They found the room
16:59
temperature superconductor and everyone freaks
17:02
out. And then, like, a few months later, the
17:04
hype quietly vanishes. What is actually going
17:08
on behind those headlines? This raises an important
17:10
question about how scientific progress is actually
17:12
made versus how it is reported to the public.
17:15
Right. The stakes are so astronomically high
17:17
that excitement often outpaces rigorous verification.
17:21
For instance, some of the most famous recent
17:23
claims involve materials that did technically
17:25
reach superconductivity near room temperature.
17:28
But there was a massive asterisk attached to
17:31
the data. They were using diamond anvils to crush
17:33
the material, right? Yes. They had to squeeze
17:36
the material between the tips of two diamonds
17:39
to create pressures approaching what you would
17:41
find near the center of the Earth. Wait, why
17:43
does crushing it help? Remember how heat causes
17:47
the atoms in the lattice to vibrate and break
17:50
apart those delicate Cooper pairs we talked about?
17:53
Yeah, the vibration ruins the pairs. Well, if
17:56
you apply immense crushing pressure... to the
17:59
material. You force the atoms so tightly together
18:02
that they physically can't vibrate wildly even
18:05
at room temperature. It basically mimics the
18:08
stabilizing effects of extreme cold. Ah, I see.
18:11
But from an engineering standpoint, that's practically
18:14
useless. I mean, you can't build an electric
18:16
motor or a cross -country power line if every
18:19
single inch of the wire has to be encased in
18:21
a planetary pressure diamond vice. Exactly. It
18:23
is entirely impractical. And beyond the high
18:25
-pressure caveats, there have been claims of
18:28
true ambient pressure superconductors that simply
18:30
evaporated under scrutiny. Very high -profile
18:33
papers have been formally retracted recently
18:35
because when other independent laboratories around
18:38
the world followed the recipe, and tried to recreate
18:40
the material, they found ordinary resistance.
18:43
The original results just couldn't be replicated.
18:45
Exactly. They couldn't be replicated. And when
18:47
people read about retractions, it's very easy
18:49
to become cynical, right? To think that science
18:51
is failing or just full of false promises. But
18:55
it's crucial to realize that this isn't science
18:58
failing. This is the scientific method working
19:01
exactly as designed. Science is a self -correcting
19:04
mechanism. When someone makes a monumental claim,
19:07
like discovering the holy grail of physics, the
19:09
entire global community immediately tries to
19:12
break that claim. They test it from every possible
19:15
angle. Right. And if the data was flawed or the
19:18
measurement tools were calibrated poorly, the
19:20
community finds out very quickly and the claim
19:22
is rejected. It demands patience. Which means
19:25
the next time a viral headline claims a room
19:27
temperature superconductor has been found, we
19:30
should probably all practice extreme patience.
19:33
Highly recommend it, yeah. Wait for the independent
19:35
labs to verify it before we start planning the
19:39
utopian future. But the reason laboratories all
19:41
over the globe continue to throw billions of
19:44
dollars and thousands of brilliant minds at this
19:47
problem, despite all the retractions and the
19:49
heartbreak, is because that utopian future is
19:52
entirely within reach. if we find the right material.
19:55
Let's talk about those stakes as we wrap up today.
19:58
Why does this matter to you listening to this
20:00
right now? Imagine a world where a cheap room
20:03
temperature superconductor is discovered. The
20:06
entire architecture of the modern world changes
20:09
overnight. Oh, absolutely. The global power grid
20:12
would become completely lossless. Think about
20:14
what that means. You could build a massive solar
20:16
farm in the deserts of Australia or North Africa
20:19
and transmit that electricity thousands of miles
20:22
to densely populated cities in Asia. or Europe
20:25
without losing a single watt to heat along the
20:28
way. That alone would change the geopolitical
20:30
map of energy. And every piece of technology
20:33
that uses an electric motor, from the fan in
20:36
your laptop to the engine in an electric car
20:39
to industrial turbines, they would become drastically
20:43
smaller, lighter, and vastly more efficient because
20:47
they wouldn't have to manage heat waste anymore.
20:49
And think about the energy storage crisis. Oh,
20:51
right. The hardest part of renewable energy is
20:54
storing the power for when the wind stops blowing
20:57
or the sun goes down. With a room temperature
20:58
superconductor, you could inject massive amounts.
21:01
of electricity into a giant loop of superconducting
21:04
wire. And it would just stay there. It would
21:06
just circulate there frictionlessly, storing
21:08
the energy indefinitely with zero degradation
21:11
until the city needs to tap into it. It's the
21:13
perfect battery. It is rare to find a single
21:16
technology that would so fundamentally upgrade
21:18
almost every aspect of human civilization at
21:20
once. Now, we don't know for certain if the laws
21:23
of chemistry and physics will actually allow
21:25
a room temperature normal pressure superconductor
21:29
to exist. Right. That's the big unknown. The
21:31
universe might simply demand that we pay the
21:33
tax of extreme cold or extreme pressure to get
21:36
zero resistance. But I want to leave you with
21:39
this final thought. Please. Think back to that
21:41
shopping trolley rolling frictionlessly out of
21:43
the parking lot. The simple, undeniable fact
21:46
that superconductivity exists at all, that the
21:50
universe does allow matter under the right conditions
21:52
to carry energy with perfect, frictionless grace,
21:56
is an incredible source of optimism. It proves
22:00
that the barrier isn't impossible. It's just
22:02
an engineering challenge. Exactly. The ultimate
22:04
energy solution to humanity's power grid and
22:07
climate challenges might just be a matter of
22:09
finding the right exotic recipe of elements waiting
22:11
quietly in a crucible somewhere right now, just
22:14
waiting for us to discover it. That is a really
22:17
profound reminder of how much of the natural
22:19
world we still have left to explore. It really
22:22
is. Well, thank you so much for joining us on
22:24
this deep dive into the bizarre, friction -free
22:27
quantum world of superconductors. Keep questioning
22:30
the everyday world around you, and we will catch
22:32
you next time.