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The phenomenon you saw here for a brief moment

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is called quantum levitation and quantum locking.

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And the object that was levitating here

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is called a superconductor.

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Superconductivity is a quantum state of matter,

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and it occurs only below a certain critical temperature.

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Now, it's quite an old phenomenon;

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it was discovered 100 years ago.

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However, only recently,

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due to several technological advancements,

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we are now able to demonstrate to you

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quantum levitation and quantum locking.

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So, a superconductor is defined by two properties.

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The first is zero electrical resistance,

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and the second is the expulsion of a magnetic field from the interior of the superconductor.

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That sounds complicated, right?

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But what is electrical resistance?

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So, electricity is the flow of electrons inside a material.

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And these electrons, while flowing,

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they collide with the atoms, and in these collisions

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they lose a certain amount of energy.

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And they dissipate this energy in the form of heat, and you know that effect.

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However, inside a superconductor there are no collisions,

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so there is no energy dissipation.

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It's quite remarkable. Think about it.

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In classical physics, there is always some friction, some energy loss.

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But not here, because it is a quantum effect.

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But that's not all, because superconductors don't like magnetic fields.

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So a superconductor will try to expel magnetic field from the inside,

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and it has the means to do that by circulating currents.

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Now, the combination of both effects --

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the expulsion of magnetic fields and zero electrical resistance --

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is exactly a superconductor.

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But the picture isn't always perfect, as we all know,

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and sometimes strands of magnetic field remain inside the superconductor.

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Now, under proper conditions, which we have here,

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these strands of magnetic field can be trapped inside the superconductor.

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And these strands of magnetic field inside the superconductor,

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they come in discrete quantities.

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Why? Because it is a quantum phenomenon. It's quantum physics.

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And it turns out that they behave like quantum particles.

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In this movie here, you can see how they flow one by one discretely.

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This is strands of magnetic field. These are not particles,

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but they behave like particles.

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So, this is why we call this effect quantum levitation and quantum locking.

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But what happens to the superconductor when we put it inside a magnetic field?

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Well, first there are strands of magnetic field left inside,

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but now the superconductor doesn't like them moving around,

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because their movements dissipate energy,

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which breaks the superconductivity state.

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So what it actually does, it locks these strands,

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which are called fluxons, and it locks these fluxons in place.

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And by doing that, what it actually does is locking itself in place.

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Why? Because any movement of the superconductor will change their place,

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will change their configuration.

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So we get quantum locking. And let me show you how this works.

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I have here a superconductor, which I wrapped up so it'd stay cold long enough.

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And when I place it on top of a regular magnet,

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it just stays locked in midair.

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(Applause)

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Now, this is not just levitation. It's not just repulsion.

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I can rearrange the fluxons, and it will be locked in this new configuration.

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Like this, or move it slightly to the right or to the left.

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So, this is quantum locking -- actually locking -- three-dimensional locking of the superconductor.

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Of course, I can turn it upside down,

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and it will remain locked.

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Now, now that we understand that this so-called levitation is actually locking,

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Yeah, we understand that.

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You won't be surprised to hear that if I take this circular magnet,

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in which the magnetic field is the same all around,

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the superconductor will be able to freely rotate around the axis of the magnet.

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Why? Because as long as it rotates, the locking is maintained.

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You see? I can adjust and I can rotate the superconductor.

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We have frictionless motion. It is still levitating, but can move freely all around.

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So, we have quantum locking and we can levitate it on top of this magnet.

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But how many fluxons, how many magnetic strands are there in a single disk like this?

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Well, we can calculate it, and it turns out, quite a lot.

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One hundred billion strands of magnetic field inside this three-inch disk.

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But that's not the amazing part yet, because there is something I haven't told you yet.

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And, yeah, the amazing part is that this superconductor that you see here

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is only half a micron thick. It's extremely thin.

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And this extremely thin layer is able to levitate more than 70,000 times its own weight.

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It's a remarkable effect. It's very strong.

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Now, I can extend this circular magnet,

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and make whatever track I want.

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For example, I can make a large circular rail here.

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And when I place the superconducting disk on top of this rail,

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it moves freely.

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(Applause)

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And again, that's not all. I can adjust its position like this, and rotate,

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and it freely moves in this new position.

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And I can even try a new thing; let's try it for the first time.

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I can take this disk and put it here,

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and while it stays here -- don't move --

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I will try to rotate the track,

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and hopefully, if I did it correctly,

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it stays suspended.

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(Applause)

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You see, it's quantum locking, not levitation.

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Now, while I'll let it circulate for a little more,

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let me tell you a little bit about superconductors.

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Now -- (Laughter) --

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So we now know that we are able to transfer enormous amount of currents inside superconductors,

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so we can use them to produce strong magnetic fields,

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such as needed in MRI machines, particle accelerators and so on.

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But we can also store energy using superconductors,

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because we have no dissipation.

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And we could also produce power cables, to transfer enormous amounts of current between power stations.

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Imagine you could back up a single power station with a single superconducting cable.

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But what is the future of quantum levitation and quantum locking?

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Well, let me answer this simple question by giving you an example.

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Imagine you would have a disk similar to the one I have here in my hand,

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three-inch diameter, with a single difference.

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The superconducting layer, instead of being half a micron thin,

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being two millimeters thin, quite thin.

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This two-millimeter-thin superconducting layer could hold 1,000 kilograms, a small car, in my hand.

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Amazing. Thank you.

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(Applause)