In the year 1919, a virtually unknown German mathematician, named Theodor Kaluza suggested a very bold and, in some ways, a very bizarre idea. He proposed that our universe might actually have more than the three dimensions that we are all aware of. That is in addition to left, right, back, forth and up, down, Kaluza proposed that there might be additional dimensions of space that for some reason we don't yet see. Now, when someone makes a bold and bizarre idea, sometimes that's all it is -- bold and bizarre, but it has nothing to do with the world around us. This particular idea, however -- although we don't yet know whether it's right or wrong, and at the end I'll discuss experiments which, in the next few years, may tell us whether it's right or wrong -- this idea has had a major impact on physics in the last century and continues to inform a lot of cutting-edge research.
1919. godine, gotovo nepoznat nemački matematičar Teodor Kaluza predstavio je vrlo smelu i na neki način bizarnu ideju. On je pretpostavio da naš Univerzum možda ima više od tri dimenzije, kojih smo svi svesni. Odnosno, da pored levo-desno, napred-nazad i gore-dole, mogu postojati dodatne prostorne dimenzije koje iz nekog razloga ne možemo da vidimo. Kada neko dođe do tako sulude i bizarne ideje, ponekad je ona samo to - suluda i bizarna i nema ništa zajedničko sa svetom oko nas. Ova ideja, međutim, iako još uvek ne znamo da li je ispravna ili pogrešna, a kasnije ću reći nešto o eksperimentima koji, u narednih nekoliko godina, mogu da nam pokažu da li je ispravna, ova ideja imala je ogroman uticaj na fiziku poslednjeg veka, i nastavlja da podstiče najsavremenija istraživanja.
So, I'd like to tell you something about the story of these extra dimensions. So where do we go? To begin we need a little bit of back story. Go to 1907. This is a year when Einstein is basking in the glow of having discovered the special theory of relativity and decides to take on a new project, to try to understand fully the grand, pervasive force of gravity. And in that moment, there are many people around who thought that that project had already been resolved. Newton had given the world a theory of gravity in the late 1600s that works well, describes the motion of planets, the motion of the moon and so forth, the motion of apocryphal of apples falling from trees, hitting people on the head. All of that could be described using Newton's work.
Zato bih voleo da vam ispričam nešto o ovim dimenzijama. Međutim, odakle početi? Za uvod u ovu priču vratićemo se u 1907. godinu. Te godine Ajnštajn je zablistao otkrivši specijalnu teoriju relativiteta, i odlučio da se posveti novom projektu: potpunom razmevanju veličanstvene sile gravitacije. U tom trenutku, mnogi su smatrali da je ta stvar već rešena. Njutn je svetu podario teoriju gravitacije krajem 17. veka, koja dobro radi, opisuje kretanje planeta, kretanje Meseca i tako dalje, nepotvrđenu priču o jabukama koje padaju sa drveća i udaraju ljude u glavu. Sve to se može opisati i objasniti rezultatima Njutnovog rada.
But Einstein realized that Newton had left something out of the story, because even Newton had written that although he understood how to calculate the effect of gravity, he'd been unable to figure out how it really works. How is it that the Sun, 93 million miles away, [that] somehow it affects the motion of the Earth? How does the Sun reach out across empty inert space and exert influence? And that is a task to which Einstein set himself -- to figure out how gravity works. And let me show you what it is that he found. So Einstein found that the medium that transmits gravity is space itself. The idea goes like this: imagine space is a substrate of all there is.
Ali, Ajnštajn je primetio da je Njutn nešto izostavio, jer i sam Njutn je pisao o tome kako iako zna da izračuna efekat gravitacije ne može sasvim da razume kako ona stvarno funkcioniše. Kako to da Sunce, 149 miliona kilometara daleko, nekako utiče na kretanje Zemlje? Na koji način Sunce kroz toliki prazan prostor utiče na Zemlju? I to je novi zadatak koji je Ajnštajn postavio sebi - da otkrije kako gravitacija funkcioniše. Pokazao bih vam sada šta je Ajnštajn otkrio. On je otkrio da je medijum koji provodi gravitaciju sam prostor. Ideja je sledeća: zamislite da je prostor supstrat svega što postoji.
Einstein said space is nice and flat, if there's no matter present. But if there is matter in the environment, such as the Sun, it causes the fabric of space to warp, to curve. And that communicates the force of gravity. Even the Earth warps space around it. Now look at the Moon. The Moon is kept in orbit, according to these ideas, because it rolls along a valley in the curved environment 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. The Earth itself is kept in orbit because it rolls along a valley in the environment that's curved because of the Sun's presence. That is this new idea about how gravity actually works.
Ajnštajn je rekao da je prostor ravan i gladak ukoliko ne postoji materija. Ali, ukoliko postoji materija, kao što je Sunce, ona izaziva da se sam prostor uvija i krivi. I na taj način ispoljava se gravitaciona sila. Čak i Zemlja krivi prostor oko sebe. Setite se Meseca. Mesec ostaje u svojoj orbiti, prema ovoj ideji, zato što se kotrlja niz dolinu u savijenom prostoru, koju Sunce i Mesec i Zemlja prave samim svojim prisustvom. Pogledajmo celu sliku. Zemlja ostaje u svojoj orbiti zato što se "kotrlja" niz dolinu u prostoru koja nastaje usled toga što postoji Sunce. To je ta nova ideja koja objašnjava gravitaciju.
Now, this idea was tested in 1919 through astronomical observations. It really works. It describes the data. And this gained Einstein prominence around the world. And that is what got Kaluza thinking. He, like Einstein, was in search of what we call a unified theory. That's one theory that might be able to describe all of nature's forces from one set of ideas, one set of principles, one master equation, if you will. So Kaluza said to himself, Einstein has been able to describe gravity in terms of warps and curves in space -- in fact, space and time, to be more precise. Maybe I can play the same game with the other known force, which was, at that time, known as the electromagnetic force -- we know of others today, but at that time that was the only other one people were thinking about. You know, the force responsible for electricity and magnetic attraction and so forth.
Ta ideja testirana je 1919. godine astronomskim posmatranjima. I ona je stvarno tačna. Potpuno opisuje podatke dobijene posmatranjem. To je proslavilo Ajnštajna širom sveta. I to je navelo Kaluzu na razmišljanje. On, kao i Ajnštajn, je tragao za onim što nazivamo "ujedinjujuća teorija". To je ona teorija koja će moći da objasni sve sile u prirodi samo jednim setom ideja, jednim skupom principa... Jednom glavnom jednačinom, ako želite. Zato je Kaluza rekao sebi sledeće: "Ajnštajn je opisao gravitaciju preko zakrivljenja prostora, ustvari zakrivljenja prostora i vremena, da budemo precizni... Možda ja mogu da se na isti način poigram sa drugom poznatom silom", a u to vreme to je bila sila elektromagnetizma. Danas znamo za još neke osnovne sile, ali tada je to bila jedina za koju su ljudi znali. Znate je, sila odgovorna za elektricitet i privlačenje magneta i tako dalje.
So Kaluza says, maybe I can play the same game and describe electromagnetic force in terms of warps and curves. That raised a question: warps and curves in what? Einstein had already used up space and time, warps and curves, to describe gravity. There didn't seem to be anything else to warp or curve. So Kaluza said, well, maybe there are more dimensions of space. He said, if I want to describe one more force, maybe I need one more dimension. So he imagined that the world had four dimensions of space, not three, and imagined that electromagnetism was warps and curves in that fourth dimension. Now here's the thing: when he wrote down the equations describing warps and curves in a universe with four space dimensions, not three, he found the old equations that Einstein had already derived in three dimensions -- those were for gravity -- but he found one more equation because of the one more dimension. And when he looked at that equation, it was none other than the equation that scientists had long known to describe the electromagnetic force. Amazing -- it just popped out. He was so excited by this realization that he ran around his house screaming, "Victory!" -- that he had found the unified theory.
Dakle, Kaluza kaže sebi da se poigra na isti način i opiše elektromagnetizam u okvirima zakrivljenja. Odmah se postavlja pitanje: zakrivljenja čega? Ajnštajn je već iskoristio prostor i vreme, njihovo zakrivljenje, kako bi opisao gravitaciju. Izgledalo je da ne postoji ništa više da se zakrivi. Pa je Kaluza rekao: "Pa, možda postoji još prostornih dimenzija. Ukoliko želim da opišem još jednu silu, možda mi treba još jedna dimenzija." Tako je zamislio svet sa četiri prostorne dimenzije, umesto tri i kako elektromagnetizam stvara zakrivljenja te četvrte dimenzije. Stvar je sada u sledećem: kada je stavio jednačine na papir, one koje opisuju zakrivljenja četvorodimenzionog prostora, dobio je iste one jednačine koje je Ajnštajn već ustanovio za trodimenzioni prostor, odnosno one za gravitaciju, ali je dobio još jednu jednačinu, zbog još jedne dimenzije. I kada ju je pogledao, to je bila ista ona jednačina koju su naučnici već mnogo vremena kotistili da opišu elektromagnetizam. Za divno čudo - ona je sama iskočila. Ovaj uvid ga je toliko uzbudio da je trčao po kući i vikao: "Pobeda!", jer je pronašao ujedinjujuću teoriju.
Now clearly, Kaluza was a man who took theory very seriously. He, in fact -- there is a story that when he wanted to learn how to swim, he read a book, a treatise on swimming -- (Laughter) -- then dove into the ocean. This is a man who would risk his life on theory. Now, but for those of us who are a little bit more practically minded, two questions immediately arise from his observation. Number one: if there are more dimensions in space, where are they? We don't seem to see them. And number two: does this theory really work in detail, when you try to apply it to the world around us? Now, the first question was answered in 1926 by a fellow named Oskar Klein. He suggested that dimensions might come in two varieties -- there might be big, easy-to-see dimensions, but there might also be tiny, curled-up dimensions, curled up so small, even though they're all around us, that we don't see them.
Kaluza je, očigledno, bio čovek koji je teoriju uzimao veoma ozbiljno. Zapravo, anegdota kaže da kada je hteo da nauči da pliva, pročitao je knjigu spisa o plivanju (Smeh) i zaronio u okean. To je čovek koji bi svoj život rizikovao za teoriju. Za nas ostale koji smo više orjentisani na praksu, iz njegovog predloga odmah su se pojavila dva pitanja. Prvo: ako postoji više dimenzija prostora - gde su? Izgleda da ih ne vidimo. I drugo: da li je ova teorija zaista ispravna, da li nepogrešivo radi kada pokušamo da je primenimo na svet oko nas? Odgovor na prvo pitanje dao nam je Oskar Klajn 1926. godine. On je pretpostavio da dimenzije mogu da postoje u dva oblika: velike - koje je lako uočiti i male, sitne, uvijene dimenzije, koje su toliko sitne da iako su oko nas jednostavno ne možemo da ih vidimo.
Let me show you that one visually. So, imagine you're looking at something like a cable supporting a traffic light. It's in Manhattan. You're in Central Park -- it's kind of irrelevant -- but the cable looks one-dimensional from a distant viewpoint, but you and I all know that it does have some thickness. It's very hard to see it, though, from far away. But if we zoom in and take the perspective of, say, a little ant walking around -- little ants are so small that they can access all of the dimensions -- the long dimension, but also this clockwise, counter-clockwise direction. And I hope you appreciate this. It took so long to get these ants to do this.
Pokazaću vam to sada. Zamislite da gledate u nešto, naprimer u kabl između semafora. Recimo da ste na Menhetnu, u Central Parku, što i nije važno sada, ali iz vaše tačke gledišta kabl izgleda jednodimenziono, ali i vi i ja znamo da on ima neku debljinu. Nju je jako teško videti iz daleka. Ali ako zumiramo pogled i zauzmemo perspektivu, recimo, malog mrava koji po njemu šeta - mali mravi su toliko sitni da mogu da pristupe svim dimenzijama - dimenziji dužine, ali i kretanja u pravcu kazaljke na satu i suprotno. Nadam se da ćete znati da cenite ovo. Trebalo je jako mnogo vremena da nateramo mrave da rade ovo.
(Laughter)
(Smeh)
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 are the ones that we can easily see, but there might be additional dimensions curled up, sort of like the circular part of that cable, so small that they have so far remained invisible. Let me show you what that would look like. So, if we take a look, say, at space itself -- I can only show, of course, two dimensions on a screen. Some of you guys will fix that one day, but anything that's not flat on a screen is a new dimension, goes smaller, smaller, smaller, and way down in the microscopic depths of space itself, this is the idea, you could have additional curled up dimensions --
Ali ovo ilustruje činjenicu da može da postoji dve vrste dimenzija: velike i male. A ideja je da su velike dimenzije oko nas one koje možemo da vidimo i da mogu da postoje dodatne dimenzije, uvijene kao sam taj kabl, i tako male da su do danas nevidljive. Pokazaću vam kako bi to moglo da izgleda. Ako pogledamo, recimo, sam prostor, a na ekranu mogu da vam pokažem samo dve dimenzije, neko će to jednog dana ispraviti, ali sve što nije ravno na ekranu jeste nova dimenzija. I ako idemo ka sitnijim i sitnijim i sitnijim, sve do mikroskopskih dubina samog prostora, ovo je ta ideja: mogu postojati dodatne uvijene dimenzije.
here is a little shape of a circle -- so small that we don't see them. But if you were a little ultra microscopic ant walking around, you could walk in the big dimensions that we all know about -- that's like the grid part -- but you could also access the tiny curled-up dimension that's so small that we can't see it with the naked eye or even with any of our most refined equipment. But deeply tucked into the fabric of space itself, the idea is there could be more dimensions, as we see there. Now that's an explanation about how the universe could have more dimensions than the ones that we see. But what about the second question that I asked: does the theory actually work when you try to apply it to the real world?
Ovde je mali krug, toliko mali da ga ne vidimo. Ali ako biste bili ultramikroskopski mrav koji tuda šeta, mogli biste da se krećete po velikim dimenzijama, koje poznajemo, to je kao mreža, ali mogli biste i da pristupite malim uvijenim dimenzijama koje su toliko male da ne mogu da se vide ni golim okom ni najfinijom opremom kojom raspolažemo danas. Ali, duboko uronjene u strukturu samog prostora mogu da postoje dodate dimenzije, pored ove tri. Na taj način objašnjavamo kako svemir može da ima dodatne dimenzije. Ali šta je sa drugim pitanjem koje sam postavio: da li teorija zapravo "radi" kada pokušamo da je primenimo na realan svet?
Well, it turns out that Einstein and Kaluza and many others worked on trying to refine this framework and apply it to the physics of the universe as was understood at the time, and, in detail, it didn't work. In detail, for instance, they couldn't get the mass of the electron to work out correctly in this theory. So many people worked on it, but by the '40s, certainly by the '50s, this strange but very compelling idea of how to unify the laws of physics had gone away. Until something wonderful happened in our age. In our era, a new approach to unify the laws of physics is being pursued by physicists such as myself, many others around the world, it's called superstring theory, as you were indicating. And the wonderful thing is that superstring theory has nothing to do at first sight with this idea of extra dimensions, but when we study superstring theory, we find that it resurrects the idea in a sparkling, new form.
Pa, ispostavlja se da su Ajnštajn i Kaluza i mnogi drugi radili na usklađivanju ove ideje i njenoj primeni u fizici tog vremena, odnosno tadašnjem razumevanju univerzima i u detaljima, ona nije radila. Na primer, nisu mogli da izračunaju tačnu masu elektrona preko ove teorije. Jako mnogo ljudi je radilo na tome, ali do 40-ih i svakako 50-ih ova čudna ali izazovna ideja o ujedinjenju zakona fizike je nestala. Sve dok se u naše vreme nešto sjajno nije dogodilo. Danas imamo novi pristup ujedinjenju zakona fizike, i time se bavimo ja i drugi fizičari, mnogi fizičari širom sveta. To nazivamo teorijom superstruna, kao što ste mogli da pretpostavite. Sjajna stvar je da ova teorija na prvi pogled nema ništa sa dodatnim dimenzijama, ali kada je proučavamo, uviđamo da ona tu ideju oživljava na jedan sasvim drugi način.
So, let me just tell you how that goes. Superstring theory -- what is it? Well, it's a theory that tries to answer the question: what are the basic, fundamental, indivisible, uncuttable constituents making up everything in the world around us? The idea is like this. So, imagine we look at a familiar object, just a candle in a holder, and imagine that we want to figure out what it is made of. 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. We also all know that atoms are not the end of the story. They have little electrons that swarm around a central nucleus with neutrons and protons. Even the neutrons and protons have smaller particles inside of them known as quarks. That is where conventional ideas stop.
Reći ću vam kako to ide. Šta je to teorija superstruna? Pa, to je teorija koja pokušava da odgovori na sledeće pitanje: koji su bazični, fundamentalni, nedeljivi činioci koji izgrađuju apsolutno sve oko nas? Ideja je sledeća. Zamislite da posmatramo poznati objekat, recimo sveću u svećnjaku, i zamislite da pokušavamo da shvatimo od čega je sastavljena. Tako krećemo na put duboko u sam objekat kako bismo ispitali sastavne delove. Jako duboko, ovo svi znamo, dolazimo do atoma. Isto tako znamo da atomi nisu kraj priče. Oni imaju male elektrone koji se kreću oko jezgra izgrađenog od protona i neutrona. Čak i protoni i neutroni sadrže manje čestice, koje smo nazvali kvarkovima. Ovde prestaje konvencionalna ideja.
Here is the new idea of string theory. Deep inside any of these particles, there is something else. This something else is this dancing filament of energy. It looks like a vibrating string -- that's where the idea, string theory comes from. And just like the vibrating strings that you just saw in a cello can vibrate in different patterns, these can also vibrate in different patterns. They don't produce different musical notes. Rather, they produce the different particles making up the world around us. So if these ideas are correct, this is what the ultra-microscopic landscape of the universe looks like. It's built up of a huge number of these little tiny filaments of vibrating energy, vibrating in different frequencies. The different frequencies produce the different particles. The different particles are responsible for all the richness in the world around us.
Sada nastupa teorija struna. Duboko u svakoj od ovih čestica postoji još nešto. To nešto su male energetske niti. Izgledaju kao strune koje vibriraju - iz te ideje proističe ova teorija. I kao što strune koje vidite na violončelu mogu da vibriraju na različite načine, tako mogu i ove. One ne proizvode različite tonove, već na taj način izgrađuju različite čestice od kojih je izgrađen svet. Tako da, ukoliko su ove ideje tačne, ovako izgledaju ultramikroskopski pejzaži univerzuma. On je izgrađen od ogromnog broja ovih malih končića vibrirajuće energije, koja vibrira različitim frekvencijama. Različitim frekvencijama izgrađuju se raziličte čestice. A različite čestice odgovorne su za sve bogatstvo sveta oko nas.
And there you see unification, because matter particles, electrons and quarks, radiation particles, photons, gravitons, are all built up from one entity. So matter and the forces of nature all are put together under the rubric of vibrating strings. And that's what we mean by a unified theory. Now here is the catch. When you study the mathematics of string theory, you find that it doesn't work in a universe that just has three dimensions of space. 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 only in a universe that has 10 dimensions of space and one dimension of time. It leads us right back to this idea of Kaluza and Klein -- that our world, when appropriately described, has more dimensions than the ones that we see.
I tu vidite ujedinjenje - zato što čestice materije, elektroni i kvarkovi, čestice zračenja - fotoni; gravitoni - sve su izgrađene od jedne stvari. Tako su sile prirode i materija spojene, određene samo vibrirajućim strunama. To je ono što podrazumevamo pod ujedinjujućom teorijom. E sad, stvar je u sledećem. Kada izučavamo matematiku teorije struna, uviđamo da ona ne funkcioniše u trodimenzionalnom prostoru. Ona ne funkcioniše ni u prostoru sa četiri dimenzije, ni pet, ni šest. Konačno, jednačine imaju smisla samo u prostoru koji ima 10 prostornih i jednu vremensku dimenziju. To nas vraća na ideju Kaluza i Klajna, da naš svet, kada se ispravno opiše, ima više dimenzija od onih koje vidimo.
Now you might think about that and say, well, 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. 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. One of the other predictions of string theory -- no, that's not one of the other predictions of string theory.
Vi sada možete da razmislite o tome i kažete sledeće - OK, ako imamo dodatne dimenzije i ako su jako uvijene, da, onda možda ne možemo da ih vidimo jer su mnogo male. Ali ako postoji civilizacija malih zelenih ljudi koja hoda tamo dole, i ako su i oni toliko mali da ne možemo da ih vidimo, onda je to tačno. Još jedno od predviđanja teorije struna. Ne, to nije još jedno od predviđanja ove teorije.
(Laughter)
(Smeh)
But it raises the question: are we just trying to hide away these extra dimensions, or do they tell us something about the world? In the remaining time, I'd like to tell you two features of them. First is, many of us believe that these extra dimensions hold the answer to what perhaps is the deepest question in theoretical physics, theoretical science. And that question is this: when we look around the world, as scientists have done for the last hundred years, there appear to be about 20 numbers that really describe our universe. These are numbers like the mass of the particles, like electrons and quarks, the strength of gravity, the strength of the electromagnetic force -- a list of about 20 numbers that have been measured with incredible precision, but nobody has an explanation for why the numbers have the particular values that they do.
Ali postavlja se pitanje: da li samo pokušavamo da sakrijemo te dimenzije, to jest, da li nam one govore nešto o svetu? U vremenu koje nam je preostalo, želeo bih da vam predstavim i dve njihove karakteristike. Prva: mnogi od nas veruju da postojanje ovih dimenzija krije odgovor na jedno od najdubljih pitanja teoretske fizike i nauke uopšte. A to pitanje je sledeće: kada gledamo svet oko nas, kao što to naučnici rade poslednjih sto godina, čini se da postoji dvadesetak brojeva koji opisuju naš Univerzum. Ti brojevi su mase pojedinih čestica, elektrona i kvarkova naprimer, jačina gravitacije, elektromagnetne sile - lista dvadesetak brojeva koji su izmereni sa neverovatnom preciznošću. Ali niko ne može da objasni zašto ti brojevi imaju baš te vrednosti.
Now, does string theory offer an answer? Not yet. But we believe the answer for why those numbers have the values they do may rely on the form of the extra dimensions. And the wonderful thing is, if those numbers had any other values than the known ones, the universe, as we know it, wouldn't exist. This is a deep question. Why are those numbers so finely tuned to allow stars to shine and planets to form, when we recognize that if you fiddle with those numbers -- if I had 20 dials up here and I let you come up and fiddle with those numbers, almost any fiddling makes the universe disappear. So can we explain those 20 numbers? And string theory suggests that those 20 numbers have to do with the extra dimensions. Let me show you how. So when we talk about the extra dimensions in string theory, it's not one extra dimension, as in the older ideas of Kaluza and Klein. This is what string theory says about the extra dimensions. They have a very rich, intertwined geometry.
Da li teorija struna nudi odgovor? Ne još. Ali verujemo da odgovor može da se krije u formi tih dodatnih dimenzija. I sjajna stvar je sledeća: kada bi ti brojevi bili drugačiji ovakav Univerzum ne bi postojao. Ovo je duboko pitanje. Zašto su te vrednosti tako fino podešene, da imamo zvezde koje sijaju i planete oko njih, kada znamo da ako se ti brojevi malo izmene - ako biste izmenili bilo koji od tih brojeva na bilo koji način, onda ceo Univerzum prestaje da postoji. Dakle, možemo li da objasnimo tih 20 brojeva? Teorija struna predlaže da su vrednosti tih brojeva u vezi sa dodatnim dimenzijama. Pokazaću vam kako. Kada govorimo o dodatnim dimenzijama u teoriji struna, ne radi se o jednoj dimenziji, kao što su mislili Kaluza i Klajn. Teorija struna nam govori sledeće o dimenzijama: njihova geometrija je prilično bogata i isprepletana.
This is an example of something known as a Calabi-Yau shape -- name isn't all that important. But, as you can see, the extra dimensions fold in on themselves and intertwine in a very interesting shape, interesting structure. And the idea is that if this is what the extra dimensions look like, then the microscopic landscape of our universe all around us would look like this on the tiniest of scales. When you swing your hand, you'd be moving around these extra dimensions over and over again, but they're so small that we wouldn't know it. So what is the physical implication, though, relevant to those 20 numbers?
Ovo je primer nečega što je poznato kao Calabi-Yau oblik. Ime nije naročito važno. Ali kao što možete da vidite, dodatne dimenzije se upliću oko sebe i prepliću u interesantne oblike i strukture. Mi mislimo da ukoliko te dimenzije izgledaju ovako, onda bi ovako izgledao i Univerzum, uveličan veliki broj puta. Kada zamahnete rukom, prolazili biste kroz ove dimenzije iznova i iznova, ali ih ne biste osetili. Kakve su, onda, fizičke posledice u vezi sa onih 20 brojeva?
Consider this. If you look at the instrument, a French horn, notice that the vibrations of the airstreams are affected by the shape of the instrument. Now in string theory, all the numbers are reflections of the way strings can vibrate. So just as those airstreams are affected by the twists and turns in the instrument, strings themselves will be affected by the vibrational patterns in the geometry within which they are moving. So let me bring some strings into the story. And if you watch these little fellows vibrating around -- they'll be there in a second -- right there, notice that they way they vibrate is affected by the geometry of the extra dimensions.
Obratite pažnju na ovo. Ako pogledate ovaj instrument, hornu, vidite da vibracije vazdušnih struja zavise od oblika samog instrumenta. U teoriji struna, svi ti brojevi su posledica načina na koji strune vibriraju. Pa kao što na vazdušne struje utiču zakrivljenja samog instrumenta, tako će i strune biti pod uticajem načina na koji vibriraju unutar geometrije u kojoj se pokreću. Pogledajmo sada neke od struna. Ako gledate kako one vibriraju, a sad ćete da ih vidite, evo ih, osmotrite kako je to njihovo vibriranje pod uticajem geometrije dodatnih dimenzija.
So, if we knew exactly what the extra dimensions look like -- we don't yet, but if we did -- we should be able to calculate the allowed notes, the allowed vibrational patterns. And if we could calculate the allowed vibrational patterns, we should be able to calculate those 20 numbers. And if the answer that we get from our calculations agrees with the values of those numbers that have been determined through detailed and precise experimentation, this in many ways would be the first fundamental explanation for why the structure of the universe is the way it is. Now, the second issue that I want to finish up with is: how might we test for these extra dimensions more directly? Is this just an interesting mathematical structure that might be able to explain some previously unexplained features of the world, or can we actually test for these extra dimensions? And we think -- and this is, I think, very exciting -- that in the next five years or so we may be able to test for the existence of these extra dimensions.
Pa kada bismo znali kako tačno te dimenzije izgledaju, što još uvek ne znamo, ali kada bismo znali, mogli bismo i da izračunamo moguće note, odnosno načine na koji mogu da vibriraju. A kada bismo to mogli da izvedemo, onda bismo dobili onih dvadesetak brojeva. I ako se vrednosti koje bismo dobili tim proračunima slažu sa vrednostima tih brojeva, koje smo ranije odredili kroz detaljne i precizne eksperimente, to bi na mnoge načine bilo prvo fundamentalno objašnjenje toga zašto je Univerzum takav kakav je. Drugi problem i sa time ću završiti, jeste kako možemo da testiramo postojanje tih dimenzija? Da li je ovo samo interesantan matematički model, koji može da objasni ranije neobjašnjiva svojstva sveta, ili zapravo možemo da dokažemo postojanje tih dimenzija eksperimentalno? Mi smatramo, i ja smatram, da je ovo jako uzbudljivo i da ćemo u narednih pet godina moći da testiramo postojanje tih dodatnih dimenzija.
Here's how it goes. In CERN, Geneva, Switzerland, a machine is being built called the Large Hadron Collider. It's a machine that will send particles around a tunnel, opposite directions, near the speed of light. Every so often those particles will be aimed at each other, so there's a head-on collision. The hope is that if the collision has enough energy, it may eject some of the debris from the collision from our dimensions, forcing it to enter into the other dimensions. How would we know it? Well, we'll measure the amount of energy after the collision, compare it to the amount of energy before, and if there's less energy after the collision than before, this will be evidence that the energy has drifted away. And if it drifts away in the right pattern that we can calculate, this will be evidence that the extra dimensions are there.
Ovako će to da izgleda. U CERN-u, u Ženevi, pravimo mašinu koja se zove Veliki sudarač čestica. Ta mašina će čestice slati kroz tunel u suprotnim pravcima i približno brzinom svetlosti. Te čestice ćemo zatim tako usmeravati da se čeono sudaraju. Nadamo se da će ti sudari biti dovoljne energije i da će moći da neke stvari iz naših dimenzija ubace u druge dimenzije. Kako ćemo znati da se to dogodilo? Pa, merićemo energiju posle sudara i uporediti je sa energijom pre sudara i ako bude bilo manje energije posle, to će biti dokaz da je deo energije sklonjen. A ako to budemo mogli da opišemo jednačinama, to će biti dokaz da dodatne dimenzije postoje.
Let me show you that idea visually. So, imagine we have a certain kind of particle called a graviton -- that's the kind of debris we expect to be ejected out, if the extra dimensions are real. But here's how the experiment will go. You take these particles. You slam them together. You slam them together, and if we are right, some of the energy of that collision will go into debris that flies off into these extra dimensions. So this is the kind of experiment that we'll be looking at in the next five, seven to 10 years or so. And if this experiment bears fruit, if we see that kind of particle ejected by noticing that there's less energy in our dimensions than when we began, this will show that the extra dimensions are real.
Pogledajte kako će to da izgleda. Zamislite česticu koja se zove graviton, to je jedna od stvari koju očekujemo da dobijemo pri sudarima, ako dodatne dimenzije postoje. Ovako će eksperiment da izgleda. Uzmete čestice i sudarite ih jako. Ako smo u pravu, deo energije tih sudara otići će na prebacivanje u druge dimenzije. Ovakave eksperimente radićemo u narednih pet, sedam ili desetak godina. I ako budu uspešni i ako vidimo taj tip čestica i ustanovimo manjak energije u našim dimenzijama, u odnosu na energiju na početku, to će biti dokaz da dodatne dimenzije zaista postoje.
And to me this is a really remarkable story, and a remarkable opportunity. Going back to Newton with absolute space -- didn't provide anything but an arena, a stage in which the events of the universe take place. Einstein comes along and says, well, space and time can warp and curve -- that's what gravity is. And now string theory comes along and says, yes, gravity, quantum mechanics, electromagnetism, all together in one package, 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. Amazing possibility. Thank you very much.
Za mene je ovo neverovatna priča, i neverovatna prilika. Vratimo se na Njutna i apsolutistički prostor - koji je samo arena, pozornica na kojoj se dešava sve u svemiru. Onda dolazi Ajnštajn i kaže sledeće: prostor i vreme mogu da se zakrivljuju i to je gravitacija. Zatim dolazi teorija struna koja kaže: da - gravitacija, kvantna mehanika, elektromagnetizam - sve zajedno su u jednom paketu, ali samo ako Univerzum ima više dimenzija od onih koje vidimo. Ovaj eksperiment će to testirati za vreme naših života. Neverovatna mogućnost. Hvala vam mnogo.
(Applause)
(Aplauz)