Making sense of string theory | Brian Greene

Translator: Rok Vidmar Reviewer: Matej Divjak

In the year 1919,

Leta 1919

a virtually unknown German mathematician, named Theodor Kaluza

je skoraj neznan nemški matematik Theodor Kaluza

suggested a very bold and, in some ways, a very bizarre idea.

predlagal zelo drzno in dokaj nenavadno zamisel.

Predpostavil je, da bi lahko naše vesolje

He proposed that our universe

might actually have more than the three dimensions

v resnici imelo več kot tri dimenzije,

that we are all aware of.

ki se jih zavedamo.

Torej, smerem levo-desno, nazaj-naprej in gor-dol,

That is in addition to left, right, back, forth and up, down,

Kaluza proposed that there might be additional dimensions of space

je Kaluza dodal možne dimenzije prostora,

ki jih zaenkrat iz različnih razlogov še ne opazimo.

that for some reason we don't yet see.

Now, when someone makes a bold and bizarre idea,

Če se pojavi drzna in nenavadna zamisel, je včasih ta samo drzna in nenavadna,

sometimes that's all it is -- bold and bizarre,

nima pa nič skupnega z resničnim svetom.

but it has nothing to do with the world around us.

This particular idea, however --

Vendar je ta zamisel, o kateri govorim,

although we don't yet know whether it's right or wrong,

čeprav še ne vemo zagotovo, če drži ali ne,

in na koncu bom povedal o eksperimentih, ki nam lahko čez nekaj let

and at the end I'll discuss experiments which, in the next few years,

povedo, če drži ali ne,

may tell us whether it's right or wrong --

ta zamisel je močno vplivala na razvoj fizike v prejšnjem stoletju

this idea has had a major impact on physics in the last century

in tudi zdaj navdihuje veliko vodilnih raziskav.

and continues to inform a lot of cutting-edge research.

Torej, rad bi vam povedal zgodbo o teh dodatnih dimenzijah.

So, I'd like to tell you something about the story of these extra dimensions.

So where do we go?

Kam se naj obrnemo? Za začetek potrebujemo uvod. Gremo v 1907.

To begin we need a little bit of back story. Go to 1907.

This is a year when Einstein is basking in the glow

To je letnica, ko Einstein počiva na lovorikah,

ker je odkril posebno teorijo relativnosti,

of having discovered the special theory of relativity

in se odloči sprejeti nov izziv -

and decides to take on a new project,

poskusil bo popolnoma razumeti veliko, prodorno silo gravitacije.

to try to understand fully the grand, pervasive force of gravity.

V tistem času je bilo veliko ljudi,

And in that moment, there are many people around

ki so menili, da je ta projekt že rešen.

who thought that that project had already been resolved.

Newton je v poznem 16. stoletju dal svetu teorijo gravitacije,

Newton had given the world a theory of gravity in the late 1600s

that works well, describes the motion of planets,

ki dela dobro: opisuje gibanje planetov,

gibanje Lune, in tako dalje,

the motion of the moon and so forth,

the motion of apocryphal of apples falling from trees,

razlaga padec legendarnih jabolk z dreves ljudem na glave.

hitting people on the head.

In vse to je moč opisati s pomočjo Newtonovega dela.

All of that could be described using Newton's work.

But Einstein realized that Newton had left something out of the story,

Ampak Einstein je ugotovil, da je Newton pustil nekaj ob strani,

because even Newton had written

saj je Newton celo zapisal,

da ni, čeprav je razumel, kako naj bi izračunal učinek gravitacije,

that although he understood how to calculate the effect of gravity,

nikakor mogel ugotoviti, kako zares deluje.

he'd been unable to figure out how it really works.

Kako je mogoče, da Sonce, 150 milijonov kilometrov daleč,

How is it that the Sun, 93 million miles away,

nekako vpliva na gibanje Zemlje?

[that] somehow it affects the motion of the Earth?

Kako Sonce vpliva skozi ta prazen, nedejaven prostor?

How does the Sun reach out across empty inert space and exert influence?

And that is a task to which Einstein set himself --

In to je bila naloga, ki si jo je Einstein zadal -

to figure out how gravity works.

ugotoviti, kako deluje gravitacija.

Naj vam pokažem, kaj je našel.

And let me show you what it is that he found.

Einstein je ugotovil,

So Einstein found

that the medium that transmits gravity is space itself.

da je posrednik gravitacije sam prostor.

The idea goes like this:

Zamisel je taka: predstavljajte si, da je prostor temelj za vse, kar je.

imagine space is a substrate of all there is.

Einstein said space is nice and flat, if there's no matter present.

Einstein je rekel, da je prostor brez snovi raven.

But if there is matter in the environment, such as the Sun,

Kadar pa v okolju snov je, denimo Sonce,

povzroči, da se tkanina prostora zvije in ukrivi.

it causes the fabric of space to warp, to curve.

In to prenaša silo gravitacije.

And that communicates the force of gravity.

Even the Earth warps space around it.

Celo Zemlja ukrivi prostor okoli sebe.

Now look at the Moon.

Poglejmo zdaj Luno.

Luna vztraja v skladu s temi zamislimi v svoji orbiti zato,

The Moon is kept in orbit, according to these ideas,

ker kroži po dolini ukrivljenega območja,

because it rolls along a valley in the curved environment

ki ga s svojo prisotnostjo ustvarijo Sonce, Luna in Zemlja.

that the Sun and the Moon and the Earth can all create by virtue of their presence.

We go to a full-frame view of this.

Poglejmo zdaj veliko sliko.

Tudi Zemlja sama se zadržuje v orbiti,

The Earth itself is kept in orbit

ker kroži po območju, ki je ukrivljeno zaradi prisotnosti Sonca.

because it rolls along a valley in the environment that's curved

because of the Sun's presence.

To je nova zamisel o tem, kako gravitacija deluje.

That is this new idea about how gravity actually works.

Now, this idea was tested in 1919 through astronomical observations.

To teorijo so leta 1919 potrdili z astronomskimi opazovanji.

It really works. It describes the data.

Res dela. Opisuje podatke.

And this gained Einstein prominence around the world.

Z njo se je Einstein uveljavil v svetu.

And that is what got Kaluza thinking.

Prav ta teorija je dala Kaluzi misliti.

Kot Einstein je tudi on poskušal najti tisto, čemur se reče "poenotena teorija".

He, like Einstein, was in search of what we call a unified theory.

That's one theory

To je ena teorija,

that might be able to describe all of nature's forces from one set of ideas,

ki bi opisovala vse naravne sile z enim naborom zamisli,

one set of principles, one master equation, if you will.

z enim naborom načel, z eno ključno enačbo, če hočete.

So Kaluza said to himself,

Kaluza si je rekel:

Einstein has been able to describe gravity

Einsteinu se je posrečilo opisati gravitacijo

in terms of warps and curves in space --

z zvitostjo in ukrivljenostjo prostora -

in fact, space and time, to be more precise.

v resnici, bolj natančno, prostora in časa.

Mogoče bi lahko storil enako s tisto drugo znano silo,

Maybe I can play the same game with the other known force,

takrat znano kot elektromagnetna sila - dandanes poznamo tudi druge,

which was, at that time, known as the electromagnetic force --

we know of others today, but at that time

a tedaj je bila to edina druga sila, o kateri so ljudje razmišljali.

that was the only other one people were thinking about.

You know, the force responsible for electricity

Sila, pristojna za elektriko

and magnetic attraction and so forth.

ter magnetno privlačnost, in tako naprej.

So Kaluza says, maybe I can play the same game

Kaluza je rekel, lahko bi naredil enako

in opisal elektromagnetno silo kot zvitja in ukrivljenosti.

and describe electromagnetic force in terms of warps and curves.

That raised a question: warps and curves in what?

Tu se je postavilo vprašanje: zvitja in ukrivljenosti v čem?

Einstein had already used up space and time,

Einstein je že porabil prostor in čas,

warps and curves, to describe gravity.

zvitja in ukrivljenosti, da je opisal gravitacijo.

There didn't seem to be anything else to warp or curve.

Ni bilo videti, da bi se dalo še kaj zvijati ali ukrivljati.

So Kaluza said, well, maybe there are more dimensions of space.

Zato je Kaluza rekel: no, mogoče pa obstaja več prostorskih razsežnosti.

He said, if I want to describe one more force,

Rekel je: če hočem opisovati še eno silo,

maybe I need one more dimension.

morda potrebujem še eno razsežnost.

So he imagined that the world had four dimensions of space, not three,

Zato si je zamislil, da ima svet štiri dimenzije, ne tri,

and imagined that electromagnetism was warps and curves

in si je zamislil, da je elektromagnetizem zvijanje in ukrivljanje

v tej četrti dimenziji.

in that fourth dimension. Now here's the thing:

Zanimivo je pa to: ko je zapisal enačbe, ki so opisovale zvijanje in ukrivljanje

when he wrote down the equations describing warps and curves

v vesolju s štirimi prostorskimi dimenzijami, ne tremi,

in a universe with four space dimensions, not three,

je našel stare enačbe, ki jih je Einstein že izpeljal v treh dimenzijah -

he found the old equations that Einstein had already derived in three dimensions --

te so bile za gravitacijo -

those were for gravity --

but he found one more equation because of the one more dimension.

pa še eno enačbo zaradi dodatne dimenzije.

And when he looked at that equation,

In ko je pogledal to enačbo,

je bila to ravno tista enačba,

it was none other than the equation

za katero so znanstveniki že dolgo vedeli, da opisuje elektromagnetno silo.

that scientists had long known to describe the electromagnetic force.

Amazing -- it just popped out.

Neverjetno - kar skočila je ven.

He was so excited by this realization

Tako je bil navdušen nad tem spoznanjem,

that he ran around his house screaming, "Victory!" --

da je začel tekati po hiši in kričati: "Zmaga!" -

ker naj bi našel poenoteno teorijo.

that he had found the unified theory.

Now clearly, Kaluza was a man who took theory very seriously.

Očitno je, da je Kaluza bil človek, ki je teorijo jemal zelo resno.

On je v bistvu -

He, in fact --

there is a story that when he wanted to learn how to swim,

znana je zgodba o tem, da je, ko se je hotel naučiti plavati,

he read a book, a treatise on swimming --

prebral knjigo, razpravo o plavanju -

(Laughter)

(Smeh)

-- then dove into the ocean.

- potem pa skočil v ocean.

This is a man who would risk his life on theory.

Ta človek bi tvegal življenje na podlagi teorije.

Now, but for those of us who are a little bit more practically minded,

A za tiste med nami, ki smo malo bolj praktičnega uma,

two questions immediately arise from his observation.

se takoj zastavita dve vprašanji glede njegovega opažanja.

Number one: if there are more dimensions in space, where are they?

Prvo: če je v prostoru več dimenzij, kje pa so?

We don't seem to see them.

Kaže, da jih ne vidimo.

And number two: does this theory really work in detail,

In drugo: ali ta teorija res drži v potankostih,

ko jo poskusiš uporabiti za opis sveta okoli nas?

when you try to apply it to the world around us?

Now, the first question was answered in 1926

Odgovor na prvo vprašanje je leta 1926 našel mož, ki se je imenoval Oskar Klein.

by a fellow named Oskar Klein.

He suggested that dimensions might come in two varieties --

Predpostavil je, da obstajata dve vrsti razsežnosti -

there might be big, easy-to-see dimensions,

utegnejo biti velike in lahko opazne dimenzije,

but there might also be tiny, curled-up dimensions,

utegnejo pa biti tudi majcene, skodrane dimenzije,

skodrane tako močno, da tudi če so vse naokrog nas,

curled up so small, even though they're all around us,

jih ne moremo videti.

that we don't see them.

Naj vam to pokažem.

Let me show you that one visually.

So, imagine you're looking at something

Predstavljajte si, da gledate kabel, ki podpira semafor.

like a cable supporting a traffic light.

It's in Manhattan. You're in Central Park -- it's kind of irrelevant --

To je Manhattan. Ste v Centralnem parku - kar niti ni važno -

but the cable looks one-dimensional from a distant viewpoint,

a kabel je od daleč videti enodimenzionalen,

but you and I all know that it does have some thickness.

a mi vsi vemo, da ima neko debelino.

No, zelo težko jo je videti od daleč.

It's very hard to see it, though, from far away.

Če se približamo in pogledamo iz perspektive, denimo,

But if we zoom in and take the perspective of, say,

a little ant walking around --

majhne mravlje, ki se sprehaja naokoli -

little ants are so small that they can access all of the dimensions --

majhne mravlje so tako majhne, da pridejo do vseh dimenzij -

the long dimension,

do podolžne dimenzije, pa tudi do obeh smeri po obsegu.

but also this clockwise, counter-clockwise direction.

And I hope you appreciate this.

Upam, da to cenite.

Mravlje smo res dolgo pripravljali do tega.

It took so long to get these ants to do this.

(Smeh)

(Laughter)

To ponazarja dejstvo, da so dimenzije lahko dveh vrst: velike in male.

But this illustrates the fact that dimensions can be of two sorts:

big and small. And the idea that maybe the big dimensions around us

In misel, da so morda velike dimenzije okrog nas

tiste, ki jih z lahkoto vidimo,

are the ones that we can easily see,

but there might be additional dimensions curled up,

da pa so morda dodatne dimenzije skodrane,

tako kot obseg tega kabla,

sort of like the circular part of that cable,

so small that they have so far remained invisible.

tako majhne, da so doslej ostale nevidne.

Let me show you what that would look like.

Naj vam pokažem, kako bi to izgledalo.

So, if we take a look, say, at space itself --

Če zdaj pogledamo, recimo, na prostor sam -

I can only show, of course, two dimensions on a screen.

seveda lahko prikažem le dve dimenziji na zaslonu.

Some of you guys will fix that one day,

Nekdo bo nekega dne to popravil,

zaenkrat pa je vse, kar na zaslonu ni ravno,

but anything that's not flat on a screen is a new dimension,

nova dimenzija, ki se manjša še in še in še,

goes smaller, smaller, smaller,

and way down in the microscopic depths of space itself,

vse do mikroskopskih globin prostora samega,

this is the idea,

to je zamisel,

you could have additional curled up dimensions --

lahko bi imel dodatne skodrane dimenzije.

here is a little shape of a circle -- so small that we don't see them.

Tu je majhna oblika kroga - tako so majhne, da jih ne vidimo.

But if you were a little ultra microscopic ant walking around,

A če bi vi bili ultramikroskopsko majcene mravlje, ki bi se sprehajale naokoli,

bi se sprehodili v znanih velikih dimenzijah -

you could walk in the big dimensions that we all know about --

that's like the grid part --

tukaj kot mreža -

a bi dosegali tudi majcene skodrane dimenzije,

but you could also access the tiny curled-up dimension

ki so tako majhne, da jih ne vidimo ne s prostim očesom,

that's so small that we can't see it with the naked eye

or even with any of our most refined equipment.

ne z nobeno najbolj izpopolnjeno opremo.

Toda globoko spodvihana v tkanino prostora samega,

But deeply tucked into the fabric of space itself,

the idea is there could be more dimensions, as we see there.

je zamisel, da bi lahko bilo več dimenzij, kar vidimo tukaj.

Now that's an explanation

No, to je razlaga

about how the universe could have more dimensions than the ones that we see.

o tem, kako bi vesolje lahko imelo več dimenzij, kot jih vidimo.

But what about the second question that I asked:

Kaj pa drugo vprašanje, ki sem ga postavil:

ali ta teorija dejansko deluje,

does the theory actually work

ko jo poskusiš uporabiti v resničnem svetu?

when you try to apply it to the real world?

Well, it turns out that Einstein and Kaluza and many others

Izkazalo se je, da so Einstein, Kaluza in mnogo drugih

worked on trying to refine this framework

poskušali izpopolniti ta okvir

in ga uporabiti v fiziki vesolja,

and apply it to the physics of the universe

kot so jo takrat razumeli, in v podrobnostih ni delovala.

as was understood at the time, and, in detail, it didn't work.

Ena podrobnost, na primer,

In detail, for instance,

they couldn't get the mass of the electron

po tej teoriji se jim izračuni za maso elektrona niso izšli prav.

to work out correctly in this theory.

So many people worked on it, but by the '40s, certainly by the '50s,

Ogromno ljudi je delalo na tem, ampak v 40-ih in zagotovo v 50-ih

je ta nenavadna, a zelo privlačna zamisel,

this strange but very compelling idea

kako poenotiti zakone fizike, že izginila.

of how to unify the laws of physics had gone away.

Until something wonderful happened in our age.

Dokler se ni nekaj prelepega zgodilo v naši dobi.

In our era, a new approach to unify the laws of physics

Nov pristop k poenotenju fizikalnih zakonov v našem času,

ki mu sledimo fiziki, vključno z mano

is being pursued by physicists such as myself,

many others around the world,

ter mnogimi drugimi po svetu.

se imenuje teorija superstrun, kot ste nakazovali.

it's called superstring theory, as you were indicating.

And the wonderful thing is that superstring theory

Najlepše je to, da teorija superstrun

na prvi pogled nima nič skupnega z zamislijo o dodatnih dimenzijah,

has nothing to do at first sight with this idea of extra dimensions,

but when we study superstring theory,

A ko preučujemo teorijo superstrun,

ugotovimo, da oživi to zamisel v iskrivi, novi obliki.

we find that it resurrects the idea in a sparkling, new form.

So, let me just tell you how that goes.

Naj vam povem, kako to gre.

Teorija superstrun - kaj je to?

Superstring theory -- what is it?

To je teorija, ki skuša odgovoriti na vprašanje:

Well, it's a theory that tries to answer the question:

kaj so osnovni, temeljni, nedeljivi, nerazrezljivi sestavni deli,

what are the basic, fundamental, indivisible, uncuttable constituents

making up everything in the world around us?

ki sestavljajo vse na svetu okoli nas?

The idea is like this.

Zamisel je taka.

Predstavljajte si, da gledamo znan predmet, svečo v svečniku,

So, imagine we look at a familiar object, just a candle in a holder,

in predstavljajte si, da želimo ugotoviti, iz česa je narejena.

and imagine that we want to figure out what it is made of.

Odpotujmo v globine predmeta in si oglejmo sestavne delce.

So we go on a journey deep inside the object and examine the constituents.

So deep inside -- we all know, you go sufficiently far down, you have atoms.

Globoko znotraj - vsi vemo, če greš dovolj globoko, prideš do atomov.

We also all know that atoms are not the end of the story.

Vemo tudi, da atomi še niso konec zgodbe.

They have little electrons that swarm around a central nucleus

Imajo majhne elektrone, ki rojijo okrog jedra v sredi,

z nevtroni in protoni.

with neutrons and protons.

Even the neutrons and protons have smaller particles inside of them known as quarks.

Celo nevtroni in protoni vsebujejo manjše delce, ki so znani kot kvarki.

That is where conventional ideas stop.

Tu se običajne zamisli končajo.

Here is the new idea of string theory.

Tu pa je nova zamisel teorije strun.

Deep inside any of these particles, there is something else.

Globoko v vseh teh delcih je še nekaj drugega.

Tisto nekaj drugega je poplesujoča nit energije.,

This something else is this dancing filament of energy.

Izgleda kot struna, ki trepeče -

It looks like a vibrating string --

od tod prihaja zamisel, teorija strun.

that's where the idea, string theory comes from.

And just like the vibrating strings that you just saw in a cello

Tako kot lahko nihajoče strune, ki ste jih videli na čelu,

can vibrate in different patterns,

nihajo po različnih vzorcih,

lahko tudi te nihajo po različnih vzorcih.

these can also vibrate in different patterns.

They don't produce different musical notes.

Ne ustvarjajo različnih tonov,

temveč ustvarjajo različne delce, ki sestavljajo svet okoli nas.

Rather, they produce the different particles making up the world around us.

Če so te zamisli pravilne,

So if these ideas are correct,

this is what the ultra-microscopic landscape of the universe looks like.

je ultra-mikroskopska pokrajina vesolja videti tako.

It's built up of a huge number

Zgrajena je iz velikanskega števila

of these little tiny filaments of vibrating energy,

teh majcenih niti nihajoče energije,

vibrating in different frequencies.

ki nihajo na različnih frekvencah.

The different frequencies produce the different particles.

Različne frekvence ustvarjajo različne delce.

The different particles are responsible

Različni delci so odgovorni

for all the richness in the world around us.

za vsa bogastva v svetu okoli nas.

V tem vidiš poenotenje,

And there you see unification,

saj so snovni delci, elektroni in kvarki,

because matter particles, electrons and quarks,

delci sevanja, fotoni, gravitoni, vsi zgrajeni iz istega bistva.

radiation particles, photons, gravitons, are all built up from one entity.

So matter and the forces of nature all are put together

Tako so snov in sile narave povezane

under the rubric of vibrating strings.

pod rubriko nihajočih strun.

And that's what we mean by a unified theory.

In to je mišljeno s poenoteno teorijo.

Now here is the catch.

Pojavi pa se zagata.

When you study the mathematics of string theory,

Ko preučuješ matematiko teorije strun,

you find that it doesn't work

odkriješ, da teorija ne deluje v vesolju, ki ima le tri razsežnosti.

in a universe that just has three dimensions of space.

Ne dela niti v vesolju s štirimi, petimi ali šestimi dimenzijami.

It doesn't work in a universe with four dimensions of space, nor five, nor six.

Finally, you can study the equations, and show that it works

Končno, lahko proučuješ enačbe in pokažeš,

da delujejo v vesolju, ki ima 10 prostorskih razsežnosti

only in a universe that has 10 dimensions of space

in eno časovno.

and one dimension of time.

It leads us right back to this idea of Kaluza and Klein --

To nas pripelje nazaj k zamisli Kaluze in Kleina,

da ima naš svet, ko je ustrezno opisan,

that our world, when appropriately described,

več dimenzij, kot jih vidimo.

has more dimensions than the ones that we see.

Now you might think about that and say, well,

To lahko premisliš in reče, no,

prav, veste, če imaš dodatne dimenzije, in če so res na tesno skodrane,

OK, you know, if you have extra dimensions, and they're really tightly curled up,

yeah, perhaps we won't see them, if they're small enough.

gotovo, najbrž jih ne bomo videli, če so dovolj majhne.

A če se sprehaja tam spodaj drobcena civilizacija zelenih človečkov,

But if there's a little tiny civilization of green people walking around down there,

and you make them small enough, and we won't see them either. That is true.

in jih narediš dovolj majhne, tudi njih ne bomo videli. To je res.

Ena od drugih napovedi teorije strun -

One of the other predictions of string theory --

no, that's not one of the other predictions of string theory.

ne, ni to ena od drugih napovedi teorije strun.

(Laughter)

(Smeh)

But it raises the question:

Postavlja pa vprašanje:

ali le poskušamo skriti te dodatne dimenzije,

are we just trying to hide away these extra dimensions,

or do they tell us something about the world?

ali pa nam povedo kaj o svetu?

In the remaining time, I'd like to tell you two features of them.

V času, ki preostane, bi rad pojasnil dve njihovi značilnosti.

First is, many of us believe that these extra dimensions

Prva je, mnogi verjamemo, da te dodatne dimenzije

skrivajo odgovor na verjetno najgloblje vprašanje

hold the answer to what perhaps is the deepest question

in theoretical physics, theoretical science.

v teoretični fiziki, v teoretični znanosti.

And that question is this: when we look around the world,

In vprašanje je: ko se oziramo po svetu,

kot so se znanstveniki zadnje stoletje,

as scientists have done for the last hundred years,

kaže, da 20 številk dobro opiše naše vesolje.

there appear to be about 20 numbers that really describe our universe.

These are numbers like the mass of the particles,

To so številke, kot mase delcev,

denimo elektronov in kvarkov, moč gravitacije,

like electrons and quarks, the strength of gravity,

the strength of the electromagnetic force --

moč elektromagnetnih sil -

a list of about 20 numbers

seznam približno 20 številk,

that have been measured with incredible precision,

ki so bile izmerjene neverjetno natančno,

but nobody has an explanation

a nihče ne zna razložiti,

zakaj imajo številke take vrednosti, kot jih imajo.

for why the numbers have the particular values that they do.

Now, does string theory offer an answer?

Zdaj, ali teorija strun ponuja odgovor? Še ne.

Not yet.

But we believe the answer for why those numbers have the values they do

A verjamemo, da odgovor, zakaj so številke take, kot so,

morda zavisi od oblike dodatnih dimenzij.

may rely on the form of the extra dimensions.

In lepo je to, da če bi imele te številke vrednosti drugačne, kot jih poznamo,

And the wonderful thing is, if those numbers

had any other values than the known ones,

vesolja, kot ga poznamo, ne bi bilo.

the universe, as we know it, wouldn't exist.

To je globoko vprašanje.

This is a deep question.

Why are those numbers so finely tuned

Zakaj so te številke tako dobro uglašene,

to allow stars to shine and planets to form,

da omogočajo, da zvezde sijejo in se planeti tvorijo,

when we recognize that if you fiddle with those numbers --

ko razumemo, da če se igračkaš s temi številkami -

if I had 20 dials up here

če bi imel tu gori 20 številčnic

and I let you come up and fiddle with those numbers,

in bi pustil, da se pridete igračkat,

almost any fiddling makes the universe disappear.

bi skoraj vsaka sprememba povzročila, da vesolje izgine.

So can we explain those 20 numbers?

Ali lahko pojasnimo teh 20 številk?

And string theory suggests that those 20 numbers

Teorija strun kaže, da je teh 20 številk

have to do with the extra dimensions.

povezanih z dodatnimi dimenzijami.

Let me show you how.

Naj vam pokažem, kako.

So when we talk about the extra dimensions in string theory,

Torej, ko govorimo o dodatnih razsežnostih v teoriji strun,

it's not one extra dimension,

to ni ena dodatna razsežnost,

as in the older ideas of Kaluza and Klein.

kot v starih zamislih Kaluze in Kleina.

To govori teorija strun o dodatnih dimenzijah.

This is what string theory says about the extra dimensions.

Imajo zelo bogato, prepleteno geometrijo.

They have a very rich, intertwined geometry.

This is an example of something known as a Calabi-Yau shape --

To je primer nečesa, kar je znano kot oblika Calabi-Yau -

name isn't all that important.

ime ni tako pomembno.

But, as you can see,

Vendar, kot vidite,

se dodatne dimenzije zvijajo vase

the extra dimensions fold in on themselves

and intertwine in a very interesting shape, interesting structure.

in se prepletajo v zelo zanimive oblike, v zanimivo strukturo.

And the idea is that if this is what the extra dimensions look like,

In zamisel je, da če tako izgledajo dodatne dimenzije,

potem bi bila mikroskopska pokrajina našega vesolja vse okoli nas

then the microscopic landscape of our universe all around us

videti takole na najmanjših lestvicah.

would look like this on the tiniest of scales.

Ko zamahneš z roko,

When you swing your hand,

you'd be moving around these extra dimensions over and over again,

bi se kar naprej pomikal okoli teh dodatnih razsežnosti,

but they're so small that we wouldn't know it.

a so tako majhne, da tega ne bi vedel.

So what is the physical implication, though, relevant to those 20 numbers?

Kaj pa je potem fizikalna posledica, povezana s temi 20 številkami?

Consider this. If you look at the instrument, a French horn,

Razmislite o tem.

Če pogledate instrument, francoski rog,

notice that the vibrations of the airstreams

opazite, da so nihanja zračnih tokov

odvisna od oblike instrumenta.

are affected by the shape of the instrument.

Now in string theory,

V teoriji strun

so vse številke odraz načina, kako strune lahko nihajo.

all the numbers are reflections of the way strings can vibrate.

So just as those airstreams

Prav tako, kot na zračne tokove

are affected by the twists and turns in the instrument,

vplivajo zavoji in obrati v instrumentu,

strings themselves will be affected

bodo na strune same vplivali

by the vibrational patterns in the geometry within which they are moving.

vzorci nihanj v geometriji, v kateri se gibljejo.

So let me bring some strings into the story.

Naj vnesem nekaj strun v zgodbo.

And if you watch these little fellows vibrating around --

In če gledate te male stvarce, kako vibrirajo naokoli

they'll be there in a second -- right there,

- vsak hip bodo tu - so že,

boste opazili, da so načini, kako vibrirajo,

notice that they way they vibrate is affected

odvisni od geometrije dodatnih dimenzij.

by the geometry of the extra dimensions.

So, if we knew exactly what the extra dimensions look like --

Torej, če bi vedeli, kako dodatne dimenzije izgledajo -

we don't yet, but if we did --

mi še ne, ampak če bi -

we should be able to calculate the allowed notes,

bi morali biti sposobni, da izračunamo dovoljene tone,

the allowed vibrational patterns.

dovoljene vzorce nihanja.

And if we could calculate the allowed vibrational patterns,

In če bi lahko izračunali dovoljene vzorce nihanja,

bi morali biti sposobni izračunati teh 20 številk.

we should be able to calculate those 20 numbers.

And if the answer that we get from our calculations

In če bi se odgovor, dobljen z našimi izračuni

agrees with the values of those numbers

ujemal z vrednostmi teh številk,

that have been determined

ki so bile določene

through detailed and precise experimentation,

s podrobnim in natančnim eksperimentiranjem,

this in many ways would be the first fundamental explanation

bi to v mnogih pogledih bila prva temeljna razlaga,

for why the structure of the universe is the way it is.

zakaj je struktura vesolja taka, kot je.

Zdaj, druga zadeva, ki jo želim dodelati je:

Now, the second issue that I want to finish up with is:

how might we test for these extra dimensions more directly?

kako bi lahko testirali te dodatne razsežnosti bolj neposredno?

Is this just an interesting mathematical structure

Ali je to le zanimiva matematična struktura,

that might be able to explain

ki bi lahko pojasnila

some previously unexplained features of the world,

nekatere prej nepojasnjene značilnosti sveta,

ali lahko dejansko preverimo te dodatne razsežnosti?

or can we actually test for these extra dimensions?

In mislimo - in to je, mislim, zelo razburljivo -

And we think -- and this is, I think, very exciting --

that in the next five years or so we may be able to test

da bomo v naslednjih petih letih ali kaj takega

lahko preverili obstoj teh dodatnih dimenzij.

for the existence of these extra dimensions.

Tako bo to šlo.

Here's how it goes. In CERN, Geneva, Switzerland,

V CERN-u, Ženeva, Švica,

a machine is being built called the Large Hadron Collider.

gradijo stroj, ki se imenuje Veliki hadronski trkalnik.

To je stroj, ki bo poslal delce po krožnem predoru,

It's a machine that will send particles around a tunnel,

v nasprotnih smereh, blizu svetlobne hitrosti.

opposite directions, near the speed of light.

Every so often those particles will be aimed at each other,

Vsake toliko časa bodo ti delci usmerjeni drug proti drugemu,

tako da se bodo čelno trčili.

so there's a head-on collision.

Upati je, da če bodo imela trčenja dovolj energije,

The hope is that if the collision has enough energy,

da bo izvrglo nekaj ostankov trka

it may eject some of the debris from the collision

from our dimensions, forcing it to enter into the other dimensions.

iz naših dimenzij v druge dimenzije.

How would we know it?

Kako bi to vedeli?

No, izmerili bomo količino energije po trčenju,

Well, we'll measure the amount of energy after the collision,

jo primerjali s količino energije prej,

compare it to the amount of energy before,

in če je energije po trčenju manj kot prej,

and if there's less energy after the collision than before,

bo to dokaz, da je energija odšla drugam.

this will be evidence that the energy has drifted away.

And if it drifts away in the right pattern that we can calculate,

Če bo odšla tako, da bomo to lahko izračunali,

bo to dokaz, da dodatne dimenzije so.

this will be evidence that the extra dimensions are there.

Naj vam pokažem to zamisel vizualno.

Let me show you that idea visually.

Imamo določeno vrsto delca, ki se imenuje graviton -

So, imagine we have a certain kind of particle called a graviton --

that's the kind of debris we expect to be ejected out,

to pa je vrsta razbitin, za katere pričakujemo, da se izvržejo,

if the extra dimensions are real.

če dodatne dimenzije res so.

Tu je, kako bo poskus potekal.

But here's how the experiment will go.

You take these particles. You slam them together.

Vzameš te delce. Treščiš jih skupaj.

Treščiš jih skupaj, in če smo imeli prav,

You slam them together, and if we are right,

some of the energy of that collision

bo nekaj energije tega trka

will go into debris that flies off into these extra dimensions.

šlo v razbitine, ki odletijo v dodatne dimenzije.

So this is the kind of experiment

To je torej take vrste eksperiment,

that we'll be looking at in the next five, seven to 10 years or so.

na katerega bomo pozorni naslednjih pet, sedem do 10 let ali kaj takega.

And if this experiment bears fruit,

In če bo ta poskus obrodil sadove,

if we see that kind of particle ejected

če opazimo, da je bil izvržen tak delec,

da obstaja manj energije v naših dimenzijah,

by noticing that there's less energy in our dimensions

than when we began,

kot na začetku,

to bo dokazalo, da dodatne dimenzije obstajajo.

this will show that the extra dimensions are real.

And to me this is a really remarkable story,

In zame je to res izjemna zgodba in izjemna priložnost.

and a remarkable opportunity. Going back to Newton with absolute space --

Če se vrnemo k Newtonu z absolutnim prostorom -

ni zagotovil nič, samo areno, oder,

didn't provide anything but an arena, a stage

in which the events of the universe take place.

kjer dogodki v vesolju potekajo.

Einstein comes along and says,

Pa pride Einstein in pravi,

v redu, prostor in čas se lahko zvijata in krivita - to je gravitacija.

well, space and time can warp and curve -- that's what gravity is.

And now string theory comes along and says,

Pa pride zdaj še teorija strun in pravi,

seveda, gravitacija, kvantna mehanika, elektromagnetizem,

yes, gravity, quantum mechanics, electromagnetism,

vse skupaj v enem paketu,

all together in one package,

a le, če je v vesolju več dimenzij, kot je tistih, ki jih vidimo.

but only if the universe has more dimensions than the ones that we see.

And this is an experiment that may test for them in our lifetime.

In to je poskus, ki to lahko preizkusi za našega življenja.

Amazing possibility.

Neverjetna možnost.

Najlepša hvala.

Thank you very much.

(Ploskanje)

(Applause)