[Script Info]
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[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:09.75,0:00:14.07,Default,,0000,0000,0000,,The phenomenon you saw here for a brief moment
Dialogue: 0,0:00:14.07,0:00:20.46,Default,,0000,0000,0000,,is called quantum levitation and quantum locking.
Dialogue: 0,0:00:20.46,0:00:24.35,Default,,0000,0000,0000,,And the object that was levitating here
Dialogue: 0,0:00:24.35,0:00:26.35,Default,,0000,0000,0000,,is called a superconductor.
Dialogue: 0,0:00:26.35,0:00:31.94,Default,,0000,0000,0000,,Superconductivity is a quantum state of matter,
Dialogue: 0,0:00:31.94,0:00:36.20,Default,,0000,0000,0000,,and it occurs only below a certain critical temperature.
Dialogue: 0,0:00:36.20,0:00:38.54,Default,,0000,0000,0000,,Now, it's quite an old phenomenon;
Dialogue: 0,0:00:38.54,0:00:40.31,Default,,0000,0000,0000,,it was discovered 100 years ago.
Dialogue: 0,0:00:40.31,0:00:42.44,Default,,0000,0000,0000,,However, only recently,
Dialogue: 0,0:00:42.44,0:00:44.80,Default,,0000,0000,0000,,due to several technological advancements,
Dialogue: 0,0:00:44.80,0:00:47.47,Default,,0000,0000,0000,,we are now able to demonstrate to you
Dialogue: 0,0:00:47.47,0:00:51.22,Default,,0000,0000,0000,,quantum levitation and quantum locking.
Dialogue: 0,0:00:51.22,0:00:57.06,Default,,0000,0000,0000,,So, a superconductor is defined by two properties.
Dialogue: 0,0:00:57.06,0:01:00.52,Default,,0000,0000,0000,,The first is zero electrical resistance,
Dialogue: 0,0:01:00.52,0:01:07.41,Default,,0000,0000,0000,,and the second is the expulsion of a magnetic field from the interior of the superconductor.
Dialogue: 0,0:01:07.41,0:01:10.30,Default,,0000,0000,0000,,That sounds complicated, right?
Dialogue: 0,0:01:10.30,0:01:13.17,Default,,0000,0000,0000,,But what is electrical resistance?
Dialogue: 0,0:01:13.17,0:01:19.42,Default,,0000,0000,0000,,So, electricity is the flow of electrons inside a material.
Dialogue: 0,0:01:19.42,0:01:22.77,Default,,0000,0000,0000,,And these electrons, while flowing,
Dialogue: 0,0:01:22.77,0:01:25.46,Default,,0000,0000,0000,,they collide with the atoms, and in these collisions
Dialogue: 0,0:01:25.46,0:01:27.68,Default,,0000,0000,0000,,they lose a certain amount of energy.
Dialogue: 0,0:01:27.68,0:01:33.28,Default,,0000,0000,0000,,And they dissipate this energy in the form of heat, and you know that effect.
Dialogue: 0,0:01:33.28,0:01:39.20,Default,,0000,0000,0000,,However, inside a superconductor there are no collisions,
Dialogue: 0,0:01:39.20,0:01:43.89,Default,,0000,0000,0000,,so there is no energy dissipation.
Dialogue: 0,0:01:43.89,0:01:46.87,Default,,0000,0000,0000,,It's quite remarkable. Think about it.
Dialogue: 0,0:01:46.87,0:01:51.95,Default,,0000,0000,0000,,In classical physics, there is always some friction, some energy loss.
Dialogue: 0,0:01:51.95,0:01:55.98,Default,,0000,0000,0000,,But not here, because it is a quantum effect.
Dialogue: 0,0:01:56.02,0:02:04.70,Default,,0000,0000,0000,,But that's not all, because superconductors don't like magnetic fields.
Dialogue: 0,0:02:04.70,0:02:09.02,Default,,0000,0000,0000,,So a superconductor will try to expel magnetic field from the inside,
Dialogue: 0,0:02:09.02,0:02:15.14,Default,,0000,0000,0000,,and it has the means to do that by circulating currents.
Dialogue: 0,0:02:15.14,0:02:18.13,Default,,0000,0000,0000,,Now, the combination of both effects --
Dialogue: 0,0:02:18.13,0:02:24.13,Default,,0000,0000,0000,,the expulsion of magnetic fields and zero electrical resistance --
Dialogue: 0,0:02:24.13,0:02:27.30,Default,,0000,0000,0000,,is exactly a superconductor.
Dialogue: 0,0:02:27.30,0:02:31.52,Default,,0000,0000,0000,,But the picture isn't always perfect, as we all know,
Dialogue: 0,0:02:31.52,0:02:38.90,Default,,0000,0000,0000,,and sometimes strands of magnetic field remain inside the superconductor.
Dialogue: 0,0:02:38.90,0:02:42.56,Default,,0000,0000,0000,,Now, under proper conditions, which we have here,
Dialogue: 0,0:02:42.56,0:02:47.64,Default,,0000,0000,0000,,these strands of magnetic field can be trapped inside the superconductor.
Dialogue: 0,0:02:47.64,0:02:53.90,Default,,0000,0000,0000,,And these strands of magnetic field inside the superconductor,
Dialogue: 0,0:02:53.90,0:02:56.75,Default,,0000,0000,0000,,they come in discrete quantities.
Dialogue: 0,0:02:56.75,0:03:00.39,Default,,0000,0000,0000,,Why? Because it is a quantum phenomenon. It's quantum physics.
Dialogue: 0,0:03:00.39,0:03:04.24,Default,,0000,0000,0000,,And it turns out that they behave like quantum particles.
Dialogue: 0,0:03:04.24,0:03:09.82,Default,,0000,0000,0000,,In this movie here, you can see how they flow one by one discretely.
Dialogue: 0,0:03:09.82,0:03:13.72,Default,,0000,0000,0000,,This is strands of magnetic field. These are not particles,
Dialogue: 0,0:03:13.72,0:03:18.01,Default,,0000,0000,0000,,but they behave like particles.
Dialogue: 0,0:03:18.01,0:03:22.20,Default,,0000,0000,0000,,So, this is why we call this effect quantum levitation and quantum locking.
Dialogue: 0,0:03:22.20,0:03:28.27,Default,,0000,0000,0000,,But what happens to the superconductor when we put it inside a magnetic field?
Dialogue: 0,0:03:28.27,0:03:32.85,Default,,0000,0000,0000,,Well, first there are strands of magnetic field left inside,
Dialogue: 0,0:03:32.85,0:03:36.97,Default,,0000,0000,0000,,but now the superconductor doesn't like them moving around,
Dialogue: 0,0:03:36.97,0:03:40.42,Default,,0000,0000,0000,,because their movements dissipate energy,
Dialogue: 0,0:03:40.42,0:03:43.37,Default,,0000,0000,0000,,which breaks the superconductivity state.
Dialogue: 0,0:03:43.37,0:03:47.72,Default,,0000,0000,0000,,So what it actually does, it locks these strands,
Dialogue: 0,0:03:47.72,0:03:53.48,Default,,0000,0000,0000,,which are called fluxons, and it locks these fluxons in place.
Dialogue: 0,0:03:53.48,0:03:59.76,Default,,0000,0000,0000,,And by doing that, what it actually does is locking itself in place.
Dialogue: 0,0:03:59.76,0:04:08.98,Default,,0000,0000,0000,,Why? Because any movement of the superconductor will change their place,
Dialogue: 0,0:04:08.98,0:04:10.79,Default,,0000,0000,0000,,will change their configuration.
Dialogue: 0,0:04:10.79,0:04:16.08,Default,,0000,0000,0000,,So we get quantum locking. And let me show you how this works.
Dialogue: 0,0:04:16.08,0:04:21.84,Default,,0000,0000,0000,,I have here a superconductor, which I wrapped up so it'd stay cold long enough.
Dialogue: 0,0:04:21.84,0:04:26.31,Default,,0000,0000,0000,,And when I place it on top of a regular magnet,
Dialogue: 0,0:04:26.31,0:04:30.18,Default,,0000,0000,0000,,it just stays locked in midair.
Dialogue: 0,0:04:30.18,0:04:34.24,Default,,0000,0000,0000,,(Applause)
Dialogue: 0,0:04:34.24,0:04:38.29,Default,,0000,0000,0000,,Now, this is not just levitation. It's not just repulsion.
Dialogue: 0,0:04:38.29,0:04:43.41,Default,,0000,0000,0000,,I can rearrange the fluxons, and it will be locked in this new configuration.
Dialogue: 0,0:04:43.41,0:04:47.44,Default,,0000,0000,0000,,Like this, or move it slightly to the right or to the left.
Dialogue: 0,0:04:47.44,0:04:55.19,Default,,0000,0000,0000,,So, this is quantum locking -- actually locking -- three-dimensional locking of the superconductor.
Dialogue: 0,0:04:55.19,0:04:57.35,Default,,0000,0000,0000,,Of course, I can turn it upside down,
Dialogue: 0,0:04:57.35,0:05:00.25,Default,,0000,0000,0000,,and it will remain locked.
Dialogue: 0,0:05:00.25,0:05:09.48,Default,,0000,0000,0000,,Now, now that we understand that this so-called levitation is actually locking,
Dialogue: 0,0:05:09.48,0:05:13.79,Default,,0000,0000,0000,,Yeah, we understand that.
Dialogue: 0,0:05:13.79,0:05:18.05,Default,,0000,0000,0000,,You won't be surprised to hear that if I take this circular magnet,
Dialogue: 0,0:05:18.05,0:05:22.02,Default,,0000,0000,0000,,in which the magnetic field is the same all around,
Dialogue: 0,0:05:22.02,0:05:27.96,Default,,0000,0000,0000,,the superconductor will be able to freely rotate around the axis of the magnet.
Dialogue: 0,0:05:27.96,0:05:33.98,Default,,0000,0000,0000,,Why? Because as long as it rotates, the locking is maintained.
Dialogue: 0,0:05:33.98,0:05:40.00,Default,,0000,0000,0000,,You see? I can adjust and I can rotate the superconductor.
Dialogue: 0,0:05:40.00,0:05:46.67,Default,,0000,0000,0000,,We have frictionless motion. It is still levitating, but can move freely all around.
Dialogue: 0,0:05:46.67,0:05:55.95,Default,,0000,0000,0000,,So, we have quantum locking and we can levitate it on top of this magnet.
Dialogue: 0,0:05:55.95,0:06:02.44,Default,,0000,0000,0000,,But how many fluxons, how many magnetic strands are there in a single disk like this?
Dialogue: 0,0:06:02.44,0:06:05.32,Default,,0000,0000,0000,,Well, we can calculate it, and it turns out, quite a lot.
Dialogue: 0,0:06:05.32,0:06:12.69,Default,,0000,0000,0000,,One hundred billion strands of magnetic field inside this three-inch disk.
Dialogue: 0,0:06:12.69,0:06:16.80,Default,,0000,0000,0000,,But that's not the amazing part yet, because there is something I haven't told you yet.
Dialogue: 0,0:06:16.80,0:06:22.41,Default,,0000,0000,0000,,And, yeah, the amazing part is that this superconductor that you see here
Dialogue: 0,0:06:22.41,0:06:29.94,Default,,0000,0000,0000,,is only half a micron thick. It's extremely thin.
Dialogue: 0,0:06:29.94,0:06:39.50,Default,,0000,0000,0000,,And this extremely thin layer is able to levitate more than 70,000 times its own weight.
Dialogue: 0,0:06:39.50,0:06:45.33,Default,,0000,0000,0000,,It's a remarkable effect. It's very strong.
Dialogue: 0,0:06:45.33,0:06:48.91,Default,,0000,0000,0000,,Now, I can extend this circular magnet,
Dialogue: 0,0:06:48.91,0:06:53.69,Default,,0000,0000,0000,,and make whatever track I want.
Dialogue: 0,0:06:53.69,0:06:57.62,Default,,0000,0000,0000,,For example, I can make a large circular rail here.
Dialogue: 0,0:06:57.62,0:07:04.50,Default,,0000,0000,0000,,And when I place the superconducting disk on top of this rail,
Dialogue: 0,0:07:04.50,0:07:08.61,Default,,0000,0000,0000,,it moves freely.
Dialogue: 0,0:07:08.61,0:07:17.99,Default,,0000,0000,0000,,(Applause)
Dialogue: 0,0:07:17.99,0:07:22.73,Default,,0000,0000,0000,,And again, that's not all. I can adjust its position like this, and rotate,
Dialogue: 0,0:07:22.73,0:07:29.17,Default,,0000,0000,0000,,and it freely moves in this new position.
Dialogue: 0,0:07:29.17,0:07:33.61,Default,,0000,0000,0000,,And I can even try a new thing; let's try it for the first time.
Dialogue: 0,0:07:33.61,0:07:39.56,Default,,0000,0000,0000,,I can take this disk and put it here,
Dialogue: 0,0:07:39.56,0:07:42.54,Default,,0000,0000,0000,,and while it stays here -- don't move --
Dialogue: 0,0:07:42.54,0:07:49.10,Default,,0000,0000,0000,,I will try to rotate the track,
Dialogue: 0,0:07:49.10,0:07:51.40,Default,,0000,0000,0000,,and hopefully, if I did it correctly,
Dialogue: 0,0:07:51.40,0:07:53.54,Default,,0000,0000,0000,,it stays suspended.
Dialogue: 0,0:07:53.54,0:08:02.99,Default,,0000,0000,0000,,(Applause)
Dialogue: 0,0:08:02.99,0:08:09.83,Default,,0000,0000,0000,,You see, it's quantum locking, not levitation.
Dialogue: 0,0:08:09.83,0:08:13.96,Default,,0000,0000,0000,,Now, while I'll let it circulate for a little more,
Dialogue: 0,0:08:13.96,0:08:17.67,Default,,0000,0000,0000,,let me tell you a little bit about superconductors.
Dialogue: 0,0:08:17.67,0:08:23.21,Default,,0000,0000,0000,,Now -- (Laughter) --
Dialogue: 0,0:08:23.21,0:08:30.24,Default,,0000,0000,0000,,So we now know that we are able to transfer enormous amount of currents inside superconductors,
Dialogue: 0,0:08:30.24,0:08:35.46,Default,,0000,0000,0000,,so we can use them to produce strong magnetic fields,
Dialogue: 0,0:08:35.46,0:08:40.65,Default,,0000,0000,0000,,such as needed in MRI machines, particle accelerators and so on.
Dialogue: 0,0:08:40.65,0:08:45.21,Default,,0000,0000,0000,,But we can also store energy using superconductors,
Dialogue: 0,0:08:45.21,0:08:47.10,Default,,0000,0000,0000,,because we have no dissipation.
Dialogue: 0,0:08:47.10,0:08:54.28,Default,,0000,0000,0000,,And we could also produce power cables, to transfer enormous amounts of current between power stations.
Dialogue: 0,0:08:54.28,0:09:03.28,Default,,0000,0000,0000,,Imagine you could back up a single power station with a single superconducting cable.
Dialogue: 0,0:09:03.28,0:09:07.76,Default,,0000,0000,0000,,But what is the future of quantum levitation and quantum locking?
Dialogue: 0,0:09:07.76,0:09:14.90,Default,,0000,0000,0000,,Well, let me answer this simple question by giving you an example.
Dialogue: 0,0:09:14.90,0:09:21.31,Default,,0000,0000,0000,,Imagine you would have a disk similar to the one I have here in my hand,
Dialogue: 0,0:09:21.31,0:09:25.19,Default,,0000,0000,0000,,three-inch diameter, with a single difference.
Dialogue: 0,0:09:25.19,0:09:30.38,Default,,0000,0000,0000,,The superconducting layer, instead of being half a micron thin,
Dialogue: 0,0:09:30.38,0:09:33.46,Default,,0000,0000,0000,,being two millimeters thin, quite thin.
Dialogue: 0,0:09:33.46,0:09:44.20,Default,,0000,0000,0000,,This two-millimeter-thin superconducting layer could hold 1,000 kilograms, a small car, in my hand.
Dialogue: 0,0:09:44.20,0:09:47.49,Default,,0000,0000,0000,,Amazing. Thank you.
Dialogue: 0,0:09:47.49,0:10:02.57,Default,,0000,0000,0000,,(Applause)