Boaz Almog "levitates" a superconductor

Translator: Morton Bast Reviewer: Thu-Huong Ha

Translator: Irma Sutlic Reviewer: Miha Helbl

The phenomenon you saw here for a brief moment

Pojav, ki ste ga tu na kratko videli,

is called quantum levitation and quantum locking.

se imenuje kvantno lebdenje in kvantna vklenjenost.

And the object that was levitating here

Predmet, ki je tu lebdel,

is called a superconductor.

pa se imenuje superprevodnik.

Superconductivity is a quantum state of matter,

Superprevodnost je kvantno stanje snovi,

and it occurs only below a certain critical temperature.

ki se pojavi le izpod določene kritične temperature.

Now, it's quite an old phenomenon;

Gre za precej star pojav,

it was discovered 100 years ago.

ki so ga odkrili pred 100 leti.

However, only recently,

Ampak šele v zadnjem času,

due to several technological advancements,

po zaslugi tehnološkega napredka,

we are now able to demonstrate to you

vam lahko pokažemo

quantum levitation and quantum locking.

kvantno lebdenje in kvantno vklenjenost.

So, a superconductor is defined by two properties.

Superprevodnik označujeta dve lastnosti.

The first is zero electrical resistance,

Prva: električna upornost je enaka nič,

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

in druga: magnetno polje je izrinjeno iz notranjosti superprevodnika.

That sounds complicated, right?

Sliši se zapleteno, kajne?

But what is electrical resistance?

Torej, kaj je električna upornost.

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

No, elektrika je tok elektronov v snovi.

And these electrons, while flowing,

Ti elektroni med svojim tokom

they collide with the atoms, and in these collisions

trkajo z atomi in ob teh trkih

they lose a certain amount of energy.

izgubijo nekaj energije.

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

To energijo razsipajo v obliki toplote, saj poznate ta efekt.

However, inside a superconductor there are no collisions,

Znotraj superprevodnika pa ni trkov

so there is no energy dissipation.

in zato se tudi energija ne razsipa.

It's quite remarkable. Think about it.

To je nekaj posebnega, kar pomislite.

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

V klasični fiziki je vedno nekaj trenja, nekaj izgube energije.

But not here, because it is a quantum effect.

Tukaj pa ne, ker gre za kvantni efekt.

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

A to še ni vse, saj superprevodniki ne marajo magnetnega polja.

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

Tako bo superprevodnik poskušal izriniti magnetno polje iz notranjosti

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

in sicer s pomočjo krožnih tokov.

Now, the combination of both effects --

No, kombinacija obeh efektov --

the expulsion of magnetic fields and zero electrical resistance --

izrinjeno magnetno polje in električna upornost enaka nič --

is exactly a superconductor.

pa je točno superprevodnik.

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

Vendar vemo, da stvari niso vedno tako popolne

and sometimes strands of magnetic field remain inside the superconductor.

in včasih silnice magnetnega polja ostanejo v notranjosti superprevodnika.

Now, under proper conditions, which we have here,

No, pod določenimi pogoji, kot jih imamo tukaj,

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

so te silnice magnetnega polja lahko ujete znotraj superprevodnika.

And these strands of magnetic field inside the superconductor,

Te silnice magnetnega polja znotraj superprevodnika

they come in discrete quantities.

se pojavljajo kot diskretne količine.

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

Zakaj? Zato, ker gre za kvantni pojav. To je kvantna fizika.

And it turns out that they behave like quantum particles.

Izkaže se, da se vedejo kot kvantni delci.

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

V tem filmčku lahko vidite, kako tečejo diskretno, ena po ena.

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

To so silnice magnetnega polja. To niso delci,

but they behave like particles.

vendar se vedejo kot delci.

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

No, zato ta efekt imenujemo kvantno lebdenje in kvantna vklenjenost.

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

A, kaj se zgodi s superprevodnikom, če ga postavimo v magnetno polje?

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

Kot prvo, nekaj silnic magnetnega polja je ostalo znotraj,

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

vendar superprevodnik ne mara, da bi se pomikale naokoli,

because their movements dissipate energy,

saj njihovi premiki razsipajo energijo,

which breaks the superconductivity state.

to pa prekine stanje superprevodnosti.

So what it actually does, it locks these strands,

Dejansko vklene te silnice,

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

ki se imenujejo fluksoni, in jih drži vklenjene na mestu.

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

S tem pa pravzaprav sebe vklene v določen položaj.

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

Zakaj? Ker bi katerikoli premik superprevodnika spremenil njihov položaj,

will change their configuration.

oziroma spremenil njihovo razporeditev.

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

Na ta način dobimo kvantno vklenjenost. Naj vam pokažem, kako to deluje.

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

Tukaj imam superprevodnik, ki sem ga zavil, da bi dovolj dolgo ostal hladen.

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

Ko ga postavim na navaden magnet,

it just stays locked in midair.

kar ostane vklenjen v zraku.

(Applause)

(Aplavz)

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

To ni le lebdenje. To ni le odboj.

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

Fluksone lahko prerazporedim in potem ostane vklenjen v novi razporeditvi.

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

Takole. Ali pa ga pomaknem desno ali levo.

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

To je torej kvantna vklenjenost - dejansko vklenjenost -

tridimenzionalna vklenjenost superprevodnika.

Of course, I can turn it upside down,

Seveda ga lahko obrnem na glavo

and it will remain locked.

in bo spet vklenjen.

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

No, sedaj razumemo, da ja to t. i. lebdenje dejansko vklenjenost.

Yeah, we understand that.

Ja, to razumemo.

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

Ne bo vas presenetilo, da ko bomo vzeli ta krožni magnet,

in which the magnetic field is the same all around,

po katerem je magnetno polje povsod enako,

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

se bo superprevodnik lahko prosto vrtel okrog osi magneta.

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

Zakaj? Dokler se vrti, se vklenjenost vzdržuje.

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

Vidite? Superprevodnik lahko premaknem in lahko ga vrtim.

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

Imamo gibanje brez trenja. Še vedno lebdi, vendar lahko prosto potuje okrog.

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

Torej imamo kvantno vklenjenost in lahko dosežemo, da lebdi nad magnetom.

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

Koliko fluksonov, koliko magnetnih silnic pa je v posameznem disku, kot je ta?

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

No, to lahko izračunamo in izkaže se, da jih je kar precej.

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

Sto milijard magnetnih silnic je v tem disku premera 7,5 cm.

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

Ampak to še ni tisti osupljivi del, nečesa vam namreč še nisem povedal.

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

Osupljivo je, da je superprevodnik pred vami

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

debel le pol mikrona. Zelo tanek je.

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

Ta izredno tanka plast je sposobna v lebdenju nositi več kot svojo 70.000-kratno težo.

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

To je izreden učinek. Velika moč.

Now, I can extend this circular magnet,

Ta krožni magnet lahko razširim

and make whatever track I want.

in naredim kakršnokoli progo.

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

Na primer, lahko naredim veliko krožno progo tukaj.

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

In ko superprevodni disk položim na to progo,

it moves freely.

se prosto giblje.

(Applause)

(Aplavz)

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

In to še ni vse. Njegov položaj lahko spremenim, takole, in ga zavrtim

and it freely moves in this new position.

in se prosto giblje v tem položaju.

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

In lahko poskusim še nekaj novega - pa poskusimo to, prvič.

I can take this disk and put it here,

Ta disk lahko postavim sem

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

in medtem ko je tu -- miruj --

I will try to rotate the track,

bom poskusil obrniti progo

and hopefully, if I did it correctly,

in upam da bo, če sem vse naredil prav,

it stays suspended.

obvisel v zraku.

(Applause)

(Aplavz)

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

Vidite, gre za kvantno vklenjenost, ne za lebdenje.

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

Medtem naj še malo kroži,

let me tell you a little bit about superconductors.

jaz pa vam povem še nekaj o superprevodnikih.

Now -- (Laughter) --

No -- (Smeh) ---

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

Vemo že, da znamo prenašati velikanske količine tokov znotraj superprevodnikov

so we can use them to produce strong magnetic fields,

in zato z njimi lahko naredimo močna magnetna polja,

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

takšna, kot jih potrebujejo MRI-naprave, pospeševalniki delcev itd.

But we can also store energy using superconductors,

Ampak s pomočjo superprevodnikov lahko tudi shranjujemo energijo,

because we have no dissipation.

saj ni izgub.

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

Lahko bi izdelali električne kable za prenos velikanskih tokov med elektrarnami.

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

Predstavljajte si, da bi posamezno elektrarno ob izpadu

lahko nadomestili prek enega samega superprevodnega kabla.

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

A, kaj je prihodnost kvantnega lebdenja in kvantne vklenjenosti?

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

Naj na to preprosto vprašanje odgovorim s primerom.

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

Predstavljajte si, da imate podoben disk, kot je ta v moji roki,

three-inch diameter, with a single difference.

premera 7,5 cm, a z eno razliko.

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

Superprevodna plast bi bila namesto pol mikrona debela

being two millimeters thin, quite thin.

dva milimetra, kar je še vedno tanko.

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

Ta dvo-milimetrska superprevodna plast bi lahko nosila

1.000 kilogramov, majhen avto, v moji roki.

Amazing. Thank you.

Osupljivo. Hvala.

(Applause)

(Aplavz)