Thank you for putting up these pictures of my colleagues over here. (Laughter) We'll be talking about them. Now, I'm going try an experiment. I don't do experiments, normally. I'm a theorist. But I'm going see what happens if I press this button. Sure enough. OK. I used to work in this field of elementary particles. What happens to matter if you chop it up very fine? What is it made of? And the laws of these particles are valid throughout the universe, and they're very much connected with the history of the universe.
Hvala vam za postavljanje ovih slika mojih kolega ovde. (Smeh). Pričaćemo o njima. Sada ću izvesti eksperiment. Obično ne radim eksperimente, teoretičar sam. Ali sada ću videti šta se dešava kada pritisnem ovo dugme. Svakako. Ok. Radio sam u ovoj oblasti elementarnih čestica. Šta se događa sa materijom ako je veoma fino iseckate? Od čega je napravljena? I zakoni ovih čestica ispravni su u celom Univerzumu i veoma su povezani sa istorijom Univerzuma.
We know a lot about four forces. There must be a lot more, but those are at very, very small distances, and we haven't really interacted with them very much yet. The main thing I want to talk about is this: that we have this remarkable experience in this field of fundamental physics that beauty is a very successful criterion for choosing the right theory. And why on earth could that be so?
Znamo dosta o ove četiri sile. Mora ih biti mnogo više, ali one su na veoma, veoma malim daljinama i još uvek nismo zaista interagovali sa njima puno. Glavna stvar o kojoj želim da pričam je sledeće: da mi imamo ovo predivno iskustvo u oblasti fundamentalne fizike da je lepota veoma uspešan kriterijum za odabir ispravne teorije. Zašto bi to tako bilo?
Well, here's an example from my own experience. It's fairly dramatic, actually, to have this happen. Three or four of us, in 1957, put forward a partially complete theory of one of these forces, this weak force. And it was in disagreement with seven -- seven, count them, seven experiments. Experiments were all wrong.
Pa, evo primera iz mog sopstvenog iskustva. Veoma je dramatično, zapravo, da vam se ovo dogodi. Troje ili četvoro nas, 1957. godine, postavilo je delom kompletnu teoriju o jednoj od ovih sila, ovoj slaboj sili. I ona se nije slagala sa sedam - sedam, prebrojte ih, sedam eksperimenata. Eksperimenti su bili pogrešni.
And we published before knowing that, because we figured it was so beautiful, it's gotta be right! The experiments had to be wrong, and they were. Now our friend over there, Albert Einstein, used to pay very little attention when people said, "You know, there's a man with an experiment that seems to disagree with special relativity. DC Miller. What about that?" And he would say, "Aw, that'll go away." (Laughter)
I mi smo to objavili pre nego što smo to znali, zato što smo shvatili da zato što je tako lepo, mora biti ispravno! Eksperimenti su morali biti pogrešni i bili su. Naš prijatelj tamo, Albert Ajnštajn, obraćao je vrlo malo pažnje na ono što su ljudi govorili, "Znate, postoji čovek sa eksperimentom koji se izgleda ne slaže sa specijalnom relativnošću. DC Miler. Šta je sa tim?" On bi rekao:"O, to će nestati." (Smeh)
Now, why does stuff like that work? That's the question. Now, yeah, what do we mean by beautiful? That's one thing. I'll try to make that clear -- partially clear. Why should it work, and is this something to do with human beings? I'll let you in on the answer to the last one that I offer, and that is, it has nothing to do with human beings. Somewhere in some other planet, orbiting some very distant star, maybe in a another galaxy, there could well be entities that are at least as intelligent as we are, and are interested in science. It's not impossible; I think there probably are lots.
Sada, zbog čega takve stvari rade? To je pitanje. Sada, da, šta mi smatramo lepim? To je jedna stvar. Pokušaću to da objasnim - delom objasnim. Zašto bi to radilo i da li to ima neke veze sa ljudskim bićima? Daću vam svoj odgovor na ovo poslednje, a to je da, ovo nema nikakve veze sa ljudskim bićima. Negde na nekoj drugoj planeti, obrćući se oko neke jako daleke zvezde, možda u drugoj galaksiji, mogli bi biti entiteti koji su najmanje inteligentni koliko i mi i zainteresovani su za nauku. Nije nemoguće; ja mislim da ih verovatno ima mnogo.
Very likely, none is close enough to interact with us. But they could be out there, very easily. And suppose they have, you know, very different sensory apparatus, and so on. They have seven tentacles, and they have 14 little funny-looking compound eyes, and a brain shaped like a pretzel. Would they really have different laws? There are lots of people who believe that, and I think it is utter baloney. I think there are laws out there, and we of course don't understand them at any given time very well -- but we try. And we try to get closer and closer.
Vrlo verovatno, nijedni nisu dovoljno blizu da bi nas kontaktirali. Ali mogli bi biti tamo, vrlo lako. I pretpostavimo da oni imaju, znate, veoma različit čulni aparat i tako dalje. Imaju sedam pipaka i 14 malih smešnih spojenih očiju i mozak u obliku perece. Da li bi oni zaista imali drugačije zakone? Mnogi ljudi veruju u to, a ja smatram da je to potpuna koještarija. Mislim da tamo negde postoje zakoni i da ih mi, naravno, ne razumemo u bilo kom trenutku vrlo dobro - ali pokušavamo. I pokušavamo da priđemo sve bliže i bliže.
And someday, we may actually figure out the fundamental unified theory of the particles and forces, what I call the "fundamental law." We may not even be terribly far from it. But even if we don't run across it in our lifetimes, we can still think there is one out there, and we're just trying to get closer and closer to it. I think that's the main point to be made. We express these things mathematically. And when the mathematics is very simple -- when in terms of some mathematical notation, you can write the theory in a very brief space, without a lot of complication -- that's essentially what we mean by beauty or elegance.
I jednog dana, mi bismo mogli zapravo otkriti fundamentalnu ujedinjenu teoriju čestica i sila, što ja nazivam "fundamentalnim zakonom". Možda čak nismo užasno daleko od njega. Ali čak i da ne naletimo na njega za vreme naših života, i dalje možemo smatrati da postoji tamo negde, a mi pokušavamo da priđemo bliže i bliže. Mislim da je to glavna poenta za izneti. Mi izražavamo ove stvari matematički. I kada je matematika veoma jednostavna - kada u smislu neke matematičke notacije možete zapisati teoriju na malo prostora, bez mnogo komplikacija - to je suštinski ono što mi smatramo lepotom ili elegancijom.
Here's what I was saying about the laws. They're really there. Newton certainly believed that. And he said, here, "It is the business of natural philosophy to find out those laws." The basic law, let's say -- here's an assumption. The assumption is that the basic law really takes the form of a unified theory of all the particles. Now, some people call that a theory of everything. That's wrong because the theory is quantum mechanical. And I won't go into a lot of stuff about quantum mechanics and what it's like, and so on. You've heard a lot of wrong things about it anyway. (Laughter) There are even movies about it with a lot of wrong stuff.
Evo šta sam govorio o zakonima. Oni su zaista tamo. Njutn je svakako verovao u to. On je rekao:"Posao je filozofije prirode da pronađe te zakone". Osnovni zakon, recimo - evo pretpostavke. Pretpostavka je da osnovni zakon zaista uzima oblik ujedinjene teorije o svim česticama. Sada, neki ljudi to nazivaju teorijom svega. To je pogrešno, jer je ta teorija kvantna mehanička. I ja neću ići i gomilu stvari o kvantnoj mehanici i kakva je ona i tako dalje. Čuli ste dosta pogrešnih stvari o njoj u svakom slučaju. (Smeh). Ima čak i filmova o njoj sa mnogo pogrešnih stvari.
But the main thing here is that it predicts probabilities. Now, sometimes those probabilities are near certainties. And in a lot of familiar cases, they of course are. But other times they're not, and you have only probabilities for different outcomes. So what that means is that the history of the universe is not determined just by the fundamental law. It's the fundamental law and this incredibly long series of accidents, or chance outcomes, that are there in addition.
Ali glavna stvar ovde je da ona predviđa verovatnoće. Sad, ponekad su te verovatnoće blizu sigurnosti. I u mnogo poznatih slučajeva, one to zaista jesu. Ali u nekim drugim prilikama nisu i imate samo verovatnoće za različite izlaze. Ono što to, dakle, znači je da istorija Univerzuma nije određena samo fundamentalnim zakonom. To su fundamentalni zakon i ovaj neverovatno dugački niz slučajnosti, ili mogućih rezultata, koji su tu sabrani.
And the fundamental theory doesn't include those chance outcomes; they are in addition. So it's not a theory of everything. And in fact, a huge amount of the information in the universe around us comes from those accidents, and not just from the fundamental laws. Now, it's often said that getting closer and closer to the fundamental laws by examining phenomena at low energies, and then higher energies, and then higher energies, or short distances, and then shorter distances, and then still shorter distances, and so on, is like peeling the skin of an onion. And we keep doing that, and build more powerful machines, accelerators for particles. We look deeper and deeper into the structure of particles, and in that way we get probably closer and closer to this fundamental law.
Fundamentalna teorija ne uključuje te moguće rezultate; oni su tu uzgredno. Dakle, to nije teorija svega. Zapravo, ogromna količina informacija u Univerzumu oko nas dolazi iz tih slučajnosti i ne samo iz fundamentalnih zakona. Sada, često je rečeno da je približavanje fundamentalnim zakonima izučavanjem fenomena na malim energijama i onda višim energijama i zatim višim energijama ili manjim rastojanjima i zatim manjim rastojanjima, a onda još manjim rastojanjima i tako dalje, jeste poput ljuštenja luka. I mi nastavljamo to da radimo i izgrađujemo moćnije mašine, akceleratore čestica. Posmatramo dublje i dublje strukturu čestica i time se verovatno približavamo sve više i više ovom fundamentalnom zakonu.
Now, what happens is that as we do that, as we peel these skins of the onion, and we get closer and closer to the underlying law, we see that each skin has something in common with the previous one, and with the next one. We write them out mathematically, and we see they use very similar mathematics. They require very similar mathematics. That is absolutely remarkable, and that is a central feature of what I'm trying to say today. Newton called it -- that's Newton, by the way -- that one.
Sada, ono što se dešava je da dok to radimo, dok ljuštimo ove slojeve luka i približavamo se zakonu ispod, mi vidimo da svaki sloj ima nešto zajedničko sa prethodnim i sa sledećim. Zapišemo ih matematički i vidimo da koriste veoma sličnu matematiku. Oni zahtevaju veoma sličnu matematiku. Ovo je apsolutno fascinanto i čini centralnu crtu onoga što pokušavam da kažem danas. Njutn je to nazivao - to je Njutn, uzgred - onaj tamo.
This one is Albert Einstein. Hi, Al! And anyway, he said, "nature conformable to herself" -- personifying nature as a female. And so what happens is that the new phenomena, the new skins, the inner skins of the slightly smaller skins of the onion that we get to, resemble the slightly larger ones. And the kind of mathematics that we had for the previous skin is almost the same as what we need for the next skin. And that's why the equations look so simple. Because they use mathematics we already have.
Ovaj je Albert Ajnštajn. Zdravo, Al! I u svakom slučaju, on je rekao "priroda dosledna sama sebi" - personifikujući prirodu kao žensko. Dakle, ono što se dešava je da novi fenomeni, novi slojevi, unutrašnji slojevi malo manjih slojeva luka na koje nailazimo, liče na one malo veće. Ona vrsta matematike koja nam je trebala za prethodni sloj je gotovo ista ona koja nam treba za naredni sloj. I to je razlog što jednačine izgledaju tako jednostavno. Zato što koriste matematiku koju već imamo.
A trivial example is this: Newton found the law of gravity, which goes like one over the square of the distance between the things gravitated. Coulomb, in France, found the same law for electric charges. Here's an example of this similarity. You look at gravity, you see a certain law. Then you look at electricity. Sure enough. The same rule. It's a very simple example. There are lots of more sophisticated examples. Symmetry is very important in this discussion. You know what it means. A circle, for example, is symmetric under rotations about the center of the circle. You rotate around the center of the circle, the circle remains unchanged. You take a sphere, in three dimensions, you rotate around the center of the sphere, and all those rotations leave the sphere alone. They are symmetries of the sphere. So we say, in general, that there's a symmetry under certain operations if those operations leave the phenomenon, or its description, unchanged.
Trivijalan primer je ovaj: Njutn je pronašao zakon gravitacije, koji ide poput jedan kroz kvadrat rastojanja između stvari koje se privlače. Kulon, u Francuskoj, pronašao je isti zakon za naelektrisanja. Eto ga primer sličnosti. Pogledate gravitaciju, vidite određeni zakon. Zatim pogledate elektricitet. Dovoljno. Isto pravilo. To je veoma jednostavan primer. Postoji još mnogo sofisticiranijih primera. Simetrija je veoma važna u ovoj diskusiji. Znate šta to znači. Krug, na primer, simetričan je pod rotacijama oko svog centra. Rotirate ga oko centra kruga, krug ostaje nepromenjen. Uzmete sferu, u tri dimenzije, rotirate je oko centra sfere i sve te rotacije čine samo sferu. To su simetrije sfere. Pa mi kažemo generalno da postoji simetrija pod određenim operacijama, ako te operacije ostavljaju fenomen ili njegov opis nepromenjen.
Maxwell's equations are of course symmetrical under rotations of all of space. Doesn't matter if we turn the whole of space around by some angle, it doesn't leave the -- doesn't change the phenomenon of electricity or magnetism. There's a new notation in the 19th century that expressed this, and if you use that notation, the equations get a lot simpler. Then Einstein, with his special theory of relativity, looked at a whole set of symmetries of Maxwell's equations, which are called special relativity. And those symmetries, then, make the equations even shorter, and even prettier, therefore.
Maksvelove jednačine su, naravno, simetrične pod rotacijama celog prostora. Nije bitno da li obrnemo ceo prostor za neki ugao, to ne ostavlja - ne menja fenomene elektriciteta ili magnetizma. Postojala je nova notacija u 19. veku koja je izražavala ovo, i ukoliko koristite tu notaciju, jednačine postaju jednostavnije. Zatim je Ajnštajn, sa svojom specijalnom teorijom relativnosti, pogledao ceo niz simetrija Maksvelovih jednačina, koje se nazivaju specijalnom relativnošću. I te simetrije, zatim, čine jednačine još kraćim, još lepšim.
Let's look. You don't have to know what these things mean, doesn't make any difference. But you can just look at the form. (Laughter) You can look at the form. You see above, at the top, a long list of equations with three components for the three directions of space: x, y and z. Then, using vector analysis, you use rotational symmetry, and you get this next set. Then you use the symmetry of special relativity and you get an even simpler set down here, showing that symmetry exhibits better and better. The more and more symmetry you have, the better you exhibit the simplicity and elegance of the theory.
Pogledajmo. Ne morate znati šta ove stvari znače, ne čini nikakvu razliku. Ali možete samo pogledati izgled. (Smeh). Možete pogledati izgled. Vidite gore, na vrhu, nalazi se duga lista jednačina sa tri komponente za tri pravca u prostoru: x, y i z. Zatim, koristeći vektorsku analizu, koristite rotacionu simetriju, te dobijate sledeći skup. Zatim koristite simetriju specijalne relativnosti i dobijate još jednostavniji skup tamo dole, pokazujući da se simetrije pokazuju sve bolje i bolje. Što više simetrija imate, bolje ćete izraziti jednostavnost i elegantnost teorije.
The last two, the first equation says that electric charges and currents give rise to all the electric and magnetic fields. The next -- second -- equation says that there is no magnetism other than that. The only magnetism comes from electric charges and currents. Someday we may find some slight hole in that argument. But for the moment, that's the case.
Poslednje dve, prva jednačina govori da naelektrisanja i električne struje stvaraju sva električna i magnetna polja. Sledeća - druga - jednačina kaže da nema magnetizma van toga. Jedini magnetizam dolazi od naelektrisanja i električnih struja. Nekog dana ćemo možda naći sitnu rupu u tom članu. Ali za sada, to je slučaj.
Now, here is a very exciting development that many people have not heard of. They should have heard of it, but it's a little tricky to explain in technical detail, so I won't do it. I'll just mention it. (Laughter) But Chen Ning Yang, called by us "Frank" Yang -- (Laughter) -- and Bob Mills put forward, 50 years ago, this generalization of Maxwell's equations, with a new symmetry. A whole new symmetry. Mathematics very similar, but there was a whole new symmetry. They hoped that this would contribute somehow to particle physics -- didn't. It didn't, by itself, contribute to particle physics.
Sada, ovde je veoma zanimljiv razvoj za koji mnogi ljudi nisu čuli. Trebalo bi da su čuli za to, ali je malo mučno objasniti to sa tehničkim detaljima, pa to neću uraditi. Samo ću spomenuti. (Smeh). Ali Čen Ning Jang, koga smo zvali "Frenk" Jang - (Smeh) - i Bob Mils postavili su, pre 50 godina, ovu generalizaciju Maksvelovih jednačina, sa novom simetrijom. Potpuno novom simetrijom. Matematika je veoma slična, ali je tu cela nova simetrija. Nadali su se da će ovo doprineti nekako fizici čestica - nije. Nije, samo po sebi, doprinelo fizici čestica.
But then some of us generalized it further. And then it did! And it gave a very beautiful description of the strong force and of the weak force. So here we say, again, what we said before: that each skin of the onion shows a similarity to the adjoining skins. So the mathematics for the adjoining skins is very similar to what we need for the new one. And therefore it looks beautiful because we already know how to write it in a lovely, concise way.
Ali onda su neki od nas ovo uopštili još više. I tada jeste! I dalo je veoma lep opis jake sile i slabe sile. Dakle ovde kažemo, ponovo, ono što smo rekli ranije: svaki sloj luka pokazuje sličnosti sa susednim slojevima. Dakle, matematika susednih slojeva je veoma slična onome što nam je potrebno za novi sloj. I zbog toga izgleda lepo. Zato što već znamo kako to da zapišemo na divni, koncizni način.
So here are the themes. We believe there is a unified theory underlying all the regularities. Steps toward unification exhibit the simplicity. Symmetry exhibits the simplicity. And then there is self-similarity across the scales -- in other words, from one skin of the onion to another one. Proximate self-similarity. And that accounts for this phenomenon. That will account for why beauty is a successful criterion for selecting the right theory.
Evo sadržaja. Verujemo da postoji ujedinjena teorija ispod svih zakonitosti. Koraci ka ujedinjenju ispoljavaju jednostavnost. Simetrija ispoljava jednostavnost. Zatim su tu i samosličnosti duž skala - drugim rečima, od jednog sloja luka do drugog. Približna samosličnost. I to objašnjava ovaj fenomen. To će objasniti zašto je lepota uspešan kriterijum za odabir ispravne teorije.
Here's what Newton himself said: "Nature is very consonant and conformable to her self." One thing he was thinking of is something that most of us take for granted today, but in his day it wasn't taken for granted. There's the story, which is not absolutely certain to be right, but a lot of people told it. Four sources told it. That when they had the plague in Cambridge, and he went down to his mother's farm -- because the university was closed -- he saw an apple fall from a tree, or on his head or something. And he realized suddenly that the force that drew the apple down to the earth could be the same as the force regulating the motions of the planets and the moon.
Evo šta je Njutn rekao: "Priroda je vrlo skladna i saglasna samoj sebi". Jedna od stvari na koje je mislio je ono što većina nas danas uzima zdravo za gotovo, ali u njegovim danima to nije bilo uzimano zdravo za gotovo. Postoji priča, za koju nije potpuno sigurno da je tačna, ali mnogi ljudi su je ispričali. Četiri izvora su je ispričala. Kada se kuga pojavila u Kembridžu i kada je on otišao na farmu svoje majke - jer je univerzitet bio zatvoren - video je jabuku da pada sa drveta ili na njegovu glavu ili tako nešto. I on je shvatio odjednom da bi sila koja je privukla jabuku dole ka zemlji mogla biti ista kao sila koja regulište kretanje planeta i meseca.
That was a big unification for those days, although today we take it for granted. It's the same theory of gravity. So he said that this principle of nature, consonance: "This principle of nature being very remote from the conceptions of philosophers, I forbore to describe it in that book, lest I should be accounted an extravagant freak ... " That's what we all have to watch out for, (Laughter) especially at this meeting. " ... and so prejudice my readers against all those things which were the main design of the book."
To je bilo veliko ujedinjenje za te dane, iako danas to uzimamo zdravo za gotovo. To je ista teorija gravitacije. Pa je on rekao da je ovaj princip prirode, harmonija: "Ovaj princip prirode daleko je od shvatanja filozofa, te sam se suzdržavao da ga opišem u toj knjizi, jer bih mogao biti smatran za ekstravagantnog čudaka..." I to je ono na šta svi moramo da pazimo. (Smeh). Naročito na ovom okupljanju. "... i tako stvoriti predrasude svojih čitalaca protiv svih onih stvari koje su bile glavne ideje knjige."
Now, who today would claim that as a mere conceit of the human mind? That the force that causes the apple to fall to the ground is the same force that causes the planets and the moon to move around, and so on? Everybody knows that. It's a property of gravitation. It's not something in the human mind. The human mind can, of course, appreciate it and enjoy it, use it, but it's not -- it doesn't stem from the human mind. It stems from the character of gravity. And that's true of all the things we're talking about. They are properties of the fundamental law. The fundamental law is such that the different skins of the onion resemble one another, and therefore the math for one skin allows you to express beautifully and simply the phenomenon of the next skin.
Sad, ko bi danas tvrdio da je to puka uobrazilja ljudskog uma? Da je sila koja izaziva pad jabuke na zemlju ista sila koja je uzrok kruženja planeta i meseca, i tako dalje? Svako to zna. To je osobina gravitacije. To nije nešto u ljudskom umu. Ljudski um može, naravno, to poštovati i uživati, koristiti, ali to nije - to ne vuče korenje iz ljudskog uma. To vuče korenje iz osobina gravitacije. I to je istina za sve stvari o kojima pričamo. One su osobine fundamentalnog zakona. Fundamentalni zakon je takav da različiti slojevi luka liče jedan na drugi i tako matematika jednog sloja dozvoljava da se izraze lepota i jednostavnost fenomena sledećeg sloja.
I say here that Newton did a lot of things that year: gravity, the laws of motion, the calculus, white light composed of all the colors of the rainbow. And he could have written quite an essay on "What I Did Over My Summer Vacation." (Laughter) So we don't have to assume these principles as separate metaphysical postulates. They follow from the fundamental theory. They are what we call emergent properties. You don't need -- you don't need something more to get something more. That's what emergence means.
Kažem ovde da je Njutn uradio dosta stvari te godine: gravitacija, zakoni kretanja, kalkulus, belo svetlo sastoji se od svih boja duge. Mogao je napisati dosta u eseju na temu "Šta sam radio na letnjem raspustu". (Smeh). Dakle ne moramo posmatrati ove principe kao odvojene metafizičke postulate. Oni proizlaze iz fundamentalne teorije. Oni su ono što zovemo proizlazećim osobinama. Nije vam potrebno - nije vam potrebno nešto više da biste dobili nešto više. To je ono što proizlaženje znači.
Life can emerge from physics and chemistry, plus a lot of accidents. The human mind can arise from neurobiology and a lot of accidents, the way the chemical bond arises from physics and certain accidents. It doesn't diminish the importance of these subjects to know that they follow from more fundamental things, plus accidents. That's a general rule, and it's critically important to realize that. You don't need something more in order to get something more. People keep asking that when they read my book, "The Quark and the Jaguar," and they say, "Isn't there something more beyond what you have there?" Presumably, they mean something supernatural. Anyway, there isn't. (Laughter) You don't need something more to explain something more. Thank you very much. (Applause)
Život može proizići iz fizike i hemije, plus mnogo slučajnosti. Ljudski um može proizići iz neurobiologije i mnogo slučajnosti, načinom na koji hemijske veze proizlaze iz fizike i određenih slučajnosti. To ne umanjuje značaj ovih predmeta da se zna da oni proizlaze iz fundamentalnijih stvari, plus slučajnosti. Postoji opšte pravilo i veoma je važno da se to shvati. Nije vam potrebno nešto više da biste dobili nešto više. Ljudi nastavljaju da postavljaju pitanja kad pročitaju moju knjigu, "Kvark i Jaguar". Oni kažu:"Nema li nečeg više iza onoga što imate tamo?" Po svoj prilici, oni misle na nešto natprirodno. U svakom slučaju, nema ga. (Smeh). Nije vam potrebno nešto više da biste objasnili nešto više. Hvala vam puno. (Aplauz)