Murray Gell-Mann: Beauty and truth in physics

Prevoditelj: Davorin Jelačić Recezent: Mislav Ante Omazić - EFZG

Thank you for putting up these pictures of my colleagues over here.

Hvala što ste postavili slike mojih kolega ovdje.

(Laughter) We'll be talking about them.

(Smijeh) Pričat ćemo o njima.

Now, I'm going try an experiment. I don't do experiments, normally. I'm a theorist.

Pokušat ću izvesti jedan eksperiment. Inače ne eksperimentiram, ja sam teoretičar.

But I'm going see what happens if I press this button.

Ali zanima me što će se dogoditi ako pritisnem ovo dugme.

Sure enough. OK. I used to work in this field of elementary particles.

Sigurno. OK. Nekad sam radio u ovom području elementarnih čestica.

What happens to matter if you chop it up very fine?

Što se događa s materijom ako je fino nasjeckate?

What is it made of?

Od čega se sastoji?

And the laws of these particles are valid throughout the universe,

A zakoni tih čestica vrijede širom svemira,

and they're very much connected with the history of the universe.

i uvelike su povezani s njegovom poviješću.

We know a lot about four forces. There must be a lot more,

Znamo mnogo o četiri sile. Mora ih biti puno više,

but those are at very, very small distances,

ali su na vrlo, vrlo malim udaljenostima,

and we haven't really interacted with them very much yet.

i još zapravo nismo ostvarivali puno interakcije s njima.

The main thing I want to talk about is this:

Glavno o čemu želim govoriti je sljedeće:

that we have this remarkable experience in this field of fundamental physics

da na polju fundamentalne fizike imamo izuzetno iskustvo

that beauty is a very successful criterion for choosing the right theory.

koje govori kako je ljepota uspješan kriterij za odabir prave teorije.

And why on earth could that be so?

Kako to, pobogu, može biti?

Well, here's an example from my own experience.

Evo primjera iz mojeg osobnog iskustva.

It's fairly dramatic, actually, to have this happen.

Prilično je dramatično, u stvari, kada se ovo dogodi.

Three or four of us, in 1957,

Nas trojica ili četvorica, godine 1957.,

put forward a partially complete theory of one of these forces, this weak force.

predložili smo djelomičnu teoriju jedne od tih sila, slabe sile.

And it was in disagreement with seven -- seven, count them, seven experiments.

Ona nije bila u skladu sa sedam – sedam, izbrojte, sedam eksperimenata.

Experiments were all wrong.

Svi su eksperimenti bili pogrešni.

And we published before knowing that,

Objavili smo teoriju prije nego što smo to znali,

because we figured it was so beautiful, it's gotta be right!

jer smo mislili da ako je tako lijepa, mora biti točna!

The experiments had to be wrong, and they were.

Eksperimenti su morali biti u krivu, i bili su.

Now our friend over there, Albert Einstein,

Naš prijatelj ondje, Albert Einstein,

used to pay very little attention when people said,

nije obraćao puno pažnje kad bi ljudi rekli,

"You know, there's a man with an experiment that seems to disagree with special relativity.

"Znate, imate čovjeka čiji eksperiment se izgleda ne slaže sa specijalnom relativnošću.

DC Miller. What about that?" And he would say, "Aw, that'll go away." (Laughter)

DC Miller. Što mislite o tome?" A on bi rekao, "O, to će proći." (Smijeh)

Now, why does stuff like that work? That's the question.

Zašto su takve stvari moguće? To je pitanje.

Now, yeah, what do we mean by beautiful? That's one thing.

Sad, što smatramo lijepim? To je jedno.

I'll try to make that clear -- partially clear.

Nastojat ću to razjasniti – djelomično razjasniti.

Why should it work, and is this something to do with human beings?

Zašto je tako, ima li to veze s ljudskim bićima?

I'll let you in on the answer to the last one that I offer,

Odgovorit ću vam na posljednje pitanje,

and that is, it has nothing to do with human beings.

a odgovor je nema, nema veze s ljudima.

Somewhere in some other planet, orbiting some very distant star,

Negdje, na nekom drugom planetu, u orbiti oko daleke zvijezde,

maybe in a another galaxy,

možda u drugoj galaksiji,

there could well be entities that are at least as intelligent as we are,

mogla bi postojati bića koja su inteligentna barem koliko i mi,

and are interested in science. It's not impossible; I think there probably are lots.

i koje zanima znanost. Nije nemoguće; mislim da ih je mnogo.

Very likely, none is close enough to interact with us.

Vjerojatno nitko od njih nije dovoljno blizu da stupi u kontakt s nama.

But they could be out there, very easily.

Ali lako bi mogli biti ondje.

And suppose they have, you know, very different sensory apparatus, and so on.

Pretpostavimo da imaju sasvim različit skup osjetila.

They have seven tentacles, and they have 14 little funny-looking compound eyes,

Imaju sedam ticala, 14 malenih složenih očiju smiješnog izgleda,

and a brain shaped like a pretzel.

i mozak u obliku pereca.

Would they really have different laws?

Da li bi oni zaista imali drugačije zakone?

There are lots of people who believe that, and I think it is utter baloney.

Mnogi ljudi u to vjeruju, a ja mislim da je to glupost.

I think there are laws out there,

Mislim kako postoje zakoni,

and we of course don't understand them at any given time very well

i mi ih, naravno, ne shvaćamo dobro u bilo koje doba

-- but we try. And we try to get closer and closer.

-- ali se trudimo. I trudimo se doći sve bliže i bliže.

And someday, we may actually figure out the fundamental unified theory

Jednoga dana, mogli bismo otkriti fundamentalnu objedinjujuću teoriju

of the particles and forces, what I call the "fundamental law."

čestica i sila, koju nazivam "fundamentalnim zakonom".

We may not even be terribly far from it.

Možda nismo ni tako daleko od tog otkrića.

But even if we don't run across it in our lifetimes,

Ali čak i ako ne dođemo do njega u našem životnom vijeku,

we can still think there is one out there,

ipak možemo smatrati da ono postoji,

and we're just trying to get closer and closer to it.

i naprosto mu se pokušavamo što više približiti.

I think that's the main point to be made.

Mislim kako je to ono što je najvažnije istaknuti.

We express these things mathematically.

Mi to izražavamo matematički.

And when the mathematics is very simple --

A kada je matematika vrlo jednostavna --

when in terms of some mathematical notation,

kad, u smislu neke matematičke notacije,

you can write the theory in a very brief space, without a lot of complication --

možete napisati teoriju koja je kratka, bez mnogo komplikacija --

that's essentially what we mean by beauty or elegance.

to je, u suštini, ono što smatramo ljepotom ili elegancijom.

Here's what I was saying about the laws. They're really there.

Eto što sam govorio o zakonima. Oni stvarno postoje.

Newton certainly believed that.

Newton je svakako u to vjerovao.

And he said, here, "It is the business of natural philosophy to find out those laws."

Rekao je, "Zadaća je filozofije prirode otkriti te zakone."

The basic law, let's say -- here's an assumption.

Temeljni zakon, recimo – evo pretpostavke.

The assumption is that the basic law really takes the form

Pretpostavka je da temeljni zakon ima oblik

of a unified theory of all the particles.

objedinjavajuće teorije svih čestica.

Now, some people call that a theory of everything.

Neki ljudi to nazivaju teorijom svega.

That's wrong because the theory is quantum mechanical.

To je pogrešno jer je teorija kvantno-mehanička.

And I won't go into a lot of stuff about quantum mechanics and what it's like, and so on.

Neću ulaziti duboko u kvantnu mehaniku i njezina svojstva.

You've heard a lot of wrong things about it anyway. (Laughter)

Ionako ste čuli puno toga pogrešnog o njoj. (Smijeh)

There are even movies about it with a lot of wrong stuff.

Imate čak i filmove o njoj s puno pogrešaka.

But the main thing here is that it predicts probabilities.

Ali najvažnija stvar je da ona predviđa vjerojatnosti.

Now, sometimes those probabilities are near certainties.

Te su vjerojatnosti ponekad skoro izvjesnosti.

And in a lot of familiar cases, they of course are.

I u mnogim poznatim slučajevima, naravno da jesu.

But other times they're not, and you have only probabilities for different outcomes.

Ali u drugim slučajevima nisu, i imate samo vjerojatnosti različitih ishoda.

So what that means is that the history of the universe is not determined just by the fundamental law.

Pa se čini kako povijest svemira nije uvjetovana jedino fundamentalnim zakonom.

It's the fundamental law and this incredibly long series of accidents,

Tu su fundamentalni zakon i nevjerojatno dug niz slučajnosti,

or chance outcomes, that are there in addition.

slučajnih ishoda, koji također postoje.

And the fundamental theory doesn't include those chance outcomes; they are in addition.

A fundamentalna teorija ne uključuje te slučajne ishode; oni su dodatak.

So it's not a theory of everything. And in fact, a huge amount of the information

Zato to nije teorija svega. Zapravo, ogromna količina informacija

in the universe around us comes from those accidents,

u svemiru nastaje iz tih slučaja,

and not just from the fundamental laws.

a ne samo iz fundamentalnih zakona.

Now, it's often said that getting closer and closer

Često se tvrdi da približavanje

to the fundamental laws by examining phenomena at low energies, and then higher energies,

fundamentalnim zakonima putem ispitivanja fenomena pri niskim, a zatim i visokim energijama,

and then higher energies, or short distances, and then shorter distances,

pa još višim energijama, na kratkim udaljenostima, pa još kraćim,

and then still shorter distances, and so on, is like peeling the skin of an onion.

pa još kraćim, da je to poput ljuštenja luka.

And we keep doing that,

Mi to činimo

and build more powerful machines, accelerators for particles.

i gradimo sve moćnije uređaje, akceleratore čestica.

We look deeper and deeper into the structure of particles,

Poniremo sve dublje i dublje u strukturu čestica,

and in that way we get probably closer and closer to this fundamental law.

i na taj se način vjerojatno približavamo fundamentalnom zakonu.

Now, what happens is that as we do that, as we peel these skins of the onion,

No, dok ljuštimo taj luk

and we get closer and closer to the underlying law,

i dolazimo sve bliže i bliže temeljnom zakonu,

we see that each skin has something in common with the previous one,

vidimo da svaka ljuska ima nešto zajedničko s prethodnom,

and with the next one. We write them out mathematically,

a i sa narednom. Ispisujemo to matematički

and we see they use very similar mathematics.

i vidimo da koriste sličnu matematiku.

They require very similar mathematics.

To zahtijeva sasvim sličnu matematiku.

That is absolutely remarkable, and that is a central feature

To je apsolutno fenomenalno, i ono najvažnije

of what I'm trying to say today.

što vam pokušavam danas reći.

Newton called it -- that's Newton, by the way -- that one.

Newton je to nazvao – ovo je Newton, usput -- onaj.

This one is Albert Einstein. Hi, Al! And anyway,

Ovo je Albert Einstein. Pozdrav, Al! Kakobilo

he said, "nature conformable to herself" -- personifying nature as a female.

rekao je, "Priroda je u skladu sa samom sobom" – personificirajući prirodu kao ženu.

And so what happens is that the new phenomena,

Dakle, događa se da novi fenomeni,

the new skins, the inner skins of the slightly smaller skins of the onion

nove ljuske, unutarnje ljuske manjih ljuski luka

that we get to, resemble the slightly larger ones.

do kojih dopiremo, sliče na malo veće ljuske.

And the kind of mathematics that we had for the previous skin

I matematika koja nam treba za prethodnu ljusku

is almost the same as what we need for the next skin.

je skoro ista kao ona koju trebamo za sljedeću.

And that's why the equations look so simple.

I zato jednadžbe izgledaju tako jednostavne.

Because they use mathematics we already have.

Jer koriste matematiku koju već imamo.

A trivial example is this: Newton found the law of gravity,

Evo trivijalnog primjera: Newton je otkrio zakon gravitacije,

which goes like one over the square of the distance between the things gravitated.

koji glasi jedan nad kvadratom udaljenosti između gravitiranih subjekata.

Coulomb, in France, found the same law for electric charges.

Coulomb, u Francuskoj, otkrio je da isti zakon vrijedi za električne naboje.

Here's an example of this similarity.

Evo primjera te sličnosti.

You look at gravity, you see a certain law.

Gledate gravitaciju, vidite određeni zakon.

Then you look at electricity. Sure enough. The same rule.

Zatim gledate elekticitet. Sigurno. Isto pravilo.

It's a very simple example.

To je vrlo jednostavan primjer.

There are lots of more sophisticated examples.

Ima mnogo profinjenijih primjera.

Symmetry is very important in this discussion.

Simetrija je vrlo važna za ovu diskusiju.

You know what it means. A circle, for example,

Znate što to znači. Krug, na primjer,

is symmetric under rotations about the center of the circle.

je simetričan po rotacijama oko središta kruga.

You rotate around the center of the circle, the circle remains unchanged.

Rotirate oko središta kruga i krug ostaje nepromijenjen.

You take a sphere, in three dimensions, you rotate around the center of the sphere,

Uzmite kuglu. U tri dimenzije rotirate oko središta,

and all those rotations leave the sphere alone.

i sve te rotacije ne mijenjaju kuglu.

They are symmetries of the sphere.

To su simetrije kugle.

So we say, in general, that there's a symmetry

Pa kažemo, općenito, da postoji simetrija

under certain operations if those operations leave the phenomenon,

u okviru određenih postupaka ako ti postupci,

or its description, unchanged.

ne mijenjaju fenomen ili njegov opis.

Maxwell's equations are of course symmetrical

Maxwellove jednadžbe su simetrične

under rotations of all of space.

u rotacijama svega prostora.

Doesn't matter if we turn the whole of space around by some angle,

Nije važno okrećemo li cijeli prostor pod nekim kutom,

it doesn't leave the -- doesn't change the phenomenon of electricity or magnetism.

to ne mijenja fenomen elektriciteta ili magnetizma.

There's a new notation in the 19th century that expressed this,

U 19. stoljeću se pojavljuje nova notacija koja to iskazuje

and if you use that notation, the equations get a lot simpler.

i ako koristite tu notaciju, jednadžbe postaju puno jednostavnije.

Then Einstein, with his special theory of relativity,

Pa Einstein, koji je, sa svojom specijalnom teorijom relativnosti,

looked at a whole set of symmetries of Maxwell's equations,

promotrio cijeli skup simetrija Maxwellovih jednadžbi,

which are called special relativity.

koje zovemo specijalna relativnost.

And those symmetries, then, make the equations even shorter, and even prettier, therefore.

I te simetrije su još skratile jednadžbe i učinile ih ljepšima nego ranije.

Let's look. You don't have to know what these things mean, doesn't make any difference.

Pogledajmo. Ne morate znati što ovo znači, uopće nije važno.

But you can just look at the form. (Laughter) You can look at the form.

Ali gledajte samo oblik. (Smijeh) Možete gledati oblik.

You see above, at the top, a long list

Vidite gore, na vrhu, dugi popis

of equations with three components for the three directions of space: x, y and z.

jednadžbi s tri komponente za tri prostorna smjera: x, y i z.

Then, using vector analysis, you use rotational symmetry, and you get this next set.

Zatim, pomoću vektorske analize, koristite rotacijsku simetriju i dobijete sljedeći skup.

Then you use the symmetry of special relativity and you get an even simpler set

Zatim koristite simetriju specijalne relativnosti i dobijete jednostavniji skup

down here, showing that symmetry exhibits better and better.

ovdje dolje, što pokazuje da se simetrija vidi sve bolje.

The more and more symmetry you have, the better you exhibit the simplicity and elegance of the theory.

Što više simetrije imate, to bolje pokazujete jednostavnost i eleganciju teorije.

The last two, the first equation says that electric charges and currents

Posljednje dvije, prva jednadžba kaže da električni naboj i struja

give rise to all the electric and magnetic fields.

povećavaju sva električna i magnetna polja.

The next -- second -- equation says that there is no magnetism other than that.

Sljedeća – druga – kaže kako nema drugog magnetizma osim toga.

The only magnetism comes from electric charges and currents.

Jedini magnetizam dolazi od električnog naboja i struje.

Someday we may find some slight hole in that argument.

Jednoga dana ćemo možda pronaći rupicu u tom argumentu.

But for the moment, that's the case.

Ali, trenutno, to je tako.

Now, here is a very exciting development that many people have not heard of.

Evo jednog vrlo uzbudljivog otkrića za koje mnogi nisu čuli.

They should have heard of it, but it's a little tricky to explain in technical detail,

Trebali su čuti za to, ali malo je zeznuto objasniti tehničke detalje,

so I won't do it. I'll just mention it. (Laughter)

pa neću ni ja. Samo ću vam spomenuti. (Smijeh)

But Chen Ning Yang, called by us "Frank" Yang -- (Laughter)

Ali Chen Ning Yang, koga mi zovemo "Frank" Yang -- (Smijeh)

-- and Bob Mills put forward, 50 years ago,

-- i Bob Mills su to predložili, prije 50 godina,

this generalization of Maxwell's equations, with a new symmetry.

uopćavanje Maxwellovih jednadžbi, s novom simetrijom.

A whole new symmetry.

Cijelom novom simetrijom.

Mathematics very similar, but there was a whole new symmetry.

Matematika je vrlo slična, ali s cijelom novom simetrijom.

They hoped that this would contribute somehow to particle physics

Nadali su se da će to nekako doprinijeti fizici čestica

-- didn't. It didn't, by itself, contribute to particle physics.

-- ali nije. Sama po sebi, nije doprinijela fizici čestica.

But then some of us generalized it further. And then it did!

A zatim su to neki od nas još poopćili. I tada je doprinijelo!

And it gave a very beautiful description of the strong force and of the weak force.

I dalo prelijep opis jake sile i slabe sile.

So here we say, again, what we said before:

Pa opet kažemo, što smo već rekli:

that each skin of the onion shows a similarity to the adjoining skins.

da svaka ljuska luka pokazuje sličnost sa susjednom ljuskom.

So the mathematics for the adjoining skins is very similar to what we need for the new one.

Pa je matematika susjednih ljuski slična onoj kakvu trebamo za novu ljusku.

And therefore it looks beautiful

I zato to izgleda lijepo,

because we already know how to write it in a lovely, concise way.

jer već znamo kako je napisati na lijep, sažet način.

So here are the themes. We believe there is a unified theory underlying all the regularities.

Ovo su teme. Vjerujemo da postoji jedinstvena teorija u podlozi svih regularnosti.

Steps toward unification exhibit the simplicity.

Koraci prema objedinjavanju iskazuju jednostavnost.

Symmetry exhibits the simplicity.

Simetrija iskazuje jednostavnost.

And then there is self-similarity across the scales -- in other words,

A postoji i međusobna sličnost na svim razinama – drugim riječima,

from one skin of the onion to another one.

od jedne ljuske luka do druge.

Proximate self-similarity. And that accounts for this phenomenon.

Približna međusobna sličnost. A to objašnjava ovaj fenomen.

That will account for why beauty is a successful criterion for selecting the right theory.

To objašnjava zašto je ljepota uspješan kriterij za odabir prave teorije.

Here's what Newton himself said:

Evo što je Newton rekao:

"Nature is very consonant and conformable to her self."

"Priroda je harmonična i u skladu sama sa sobom."

One thing he was thinking of is something that most of us take for granted today,

On je razmišljao o nečemu što većina nas danas uzima zdravo za gotovo,

but in his day it wasn't taken for granted.

ali u njegovo doba se nije uzimalo zdravo za gotovo.

There's the story, which is not absolutely certain to be right, but a lot of people told it.

Ima priča, za koju nije sasvim sigurno da je istinita, ali se puno puta prepričavala.

Four sources told it. That when they had the plague in Cambridge,

Četiri izvora ju je pričalo. U vrijeme kuge u Cambridgeu,

and he went down to his mother's farm -- because the university was closed --

kad je otišao na majčinu farmu – jer je sveučilište zatvoreno --

he saw an apple fall from a tree, or on his head or something.

vidio je kako jabuka pada sa stabla, ili mu je pala na glavu.

And he realized suddenly that the force that drew the apple down to the earth

I iznenada je shvatio da bi sila koja je povukla jabuku prema zemlji

could be the same as the force regulating the motions of the planets and the moon.

mogla biti ista ona sila koja upravlja kretanjem planeta i Mjeseca.

That was a big unification for those days, although today we take it for granted.

To je bila objedinjujuća teorija onih dana, premda je danas uzimamo zdravo za gotovo.

It's the same theory of gravity.

To je ta teorija gravitacije.

So he said that this principle of nature, consonance:

Pa je rekao za taj prirodni princip, harmoniju:

"This principle of nature being very remote from the conceptions of philosophers,

"Taj je prirodni princip jako daleko od filozofskih koncepata,

I forbore to describe it in that book,

i suzdržavam se da ga opišem u knjizi,

lest I should be accounted an extravagant freak ... "

da ne bih bio smatran ekstravagantnom nakazom ... "

That's what we all have to watch out for, (Laughter) especially at this meeting.

Svi se mi moramo toga čuvati, (Smijeh) naročito na ovom skupu.

" ... and so prejudice my readers against all those things which were the main design of the book."

" ... i izazvao predrasude u čitatelja protiv svih teza koje su temelj ove knjige."

Now, who today would claim that as a mere conceit of the human mind?

Tko bi danas tvrdio da je to izmišljotina ljudskog uma?

That the force that causes the apple to fall to the ground

Da je sila uslijed koje jabuka pada na tlo

is the same force that causes the planets and the moon to move around,

ista ona sila koja vodi kretanje planeta i Mjeseca?

and so on? Everybody knows that. It's a property of gravitation.

Svi to znaju. To je svojstvo gravitacije.

It's not something in the human mind. The human mind can, of course, appreciate it

Ta ideja nije u ljudskom umu. Ljudski um je, naravno, može cijeniti

and enjoy it, use it, but it's not -- it doesn't stem from the human mind.

i uživati u njoj, rabiti je, ali ona nije samo plod ljudskog uma.

It stems from the character of gravity.

Ona proistječe iz svojstava gravitacije.

And that's true of all the things we're talking about.

Isto vrijedi za sve o čemu pričamo.

They are properties of the fundamental law.

Sve su to svojstva fundamentalnog zakona.

The fundamental law is such that the different skins of the onion resemble one another,

Fundamentalni zakon je takav da različite ljuske luka sliče jedna na drugu,

and therefore the math for one skin allows you to express beautifully and simply

i zato vam matematika jedne ljuske omogućava da lijepo i jednostavno

the phenomenon of the next skin.

objasnite fenomen sljedeće ljuske.

I say here that Newton did a lot of things that year:

Newton je otkrio puno stvari te godine:

gravity, the laws of motion, the calculus, white light composed of all the colors of the rainbow.

gravitaciju, zakone gibanja, račun, da se bijela svjetlost sastoji od duginih boja.

And he could have written quite an essay on "What I Did Over My Summer Vacation."

I mogao je napisati popriličan esej na temu "Što sam radio tijekom ljetnih ferija.“

(Laughter)

(Smijeh)

So we don't have to assume these principles as separate metaphysical postulates.

Znači, ne moramo tretirati te principe kao zasebne metafizičke postulate.

They follow from the fundamental theory.

Oni proistječu iz fundamentalne teorije.

They are what we call emergent properties.

Oni su ono što nazivamo pojavna svojstva.

You don't need -- you don't need something more to get something more.

Ne trebate nešto više da biste dobili nešto više.

That's what emergence means.

To je ono što pojavnost znači.

Life can emerge from physics and chemistry, plus a lot of accidents.

Život se može pojaviti iz fizike i kemije, plus mnogo slučajnosti.

The human mind can arise from neurobiology and a lot of accidents,

Ljudski um može nastati iz neurobiologije i mnogih slučajnosti,

the way the chemical bond arises from physics and certain accidents.

isto kao što se kemijske veze rađaju iz fizike i određenih slučajnosti.

It doesn't diminish the importance of these subjects

Važnost tih stvari ne umanjuje spoznaja

to know that they follow from more fundamental things, plus accidents.

da proistječu iz fundamentalnijih stvari, plus slučaja.

That's a general rule, and it's critically important to realize that.

To je opće pravilo i kritično je važno to shvatiti.

You don't need something more in order to get something more.

Ne trebate nešto više da biste dobili nešto više.

People keep asking that when they read my book, "The Quark and the Jaguar,"

Ljudi uvijek pitaju čitajući moju knjigu, "Kvark i jaguar,"

and they say, "Isn't there something more beyond what you have there?"

"Ne postoji li i nešto povrh ovoga što spominjete ovdje?"

Presumably, they mean something supernatural.

Za pretpostaviti je da misle na nešto nadnaravno.

Anyway, there isn't. (Laughter)

Bilo kako bilo, ne postoji. (Smijeh)

You don't need something more to explain something more.

Ne treba vam nešto više da biste objasnili nešto više.

Thank you very much. (Applause)

Hvala vam lijepa. (Pljesak)