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.
Godine 1919. praktički nepoznat njemački matematičar po imenu Theodor Kaluza iznio je vrlo odvažnu i, na neki način, bizarnu ideju. Rekao je da bi naš svemir mogao imati više od tri dimenzije koje svi poznajemo. Pored lijevo, desno, naprijed, nazad i gore, dolje, Kaluza je predložio da bi mogle postojati dodatne prostorne dimenzije koje iz nekog razloga još ne vidimo. Naime, kada netko iznese odvažnu i bizarnu ideju, ona je nekad samo to -- odvažna i bizarna, ali nema nikakve veze sa svijetom oko nas. Međutim, ova ideja -- iako još ne znamo je li valjana ili ne, a na kraju ću razmotriti pokuse koji bi nam u sljedećih nekoliko godina, mogli reći je li valjana ili ne -- ova ideja imala je veliki utjecaj na fizičare u prošlom stoljeću i nadalje nadahnjuje mnoga najnaprednija 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.
Stoga bih vam htio ispričati nešto o ovim dodatnim dimenzijama. Dakle, kamo idemo? Za početak trebamo malo pozadine. Idemo u 1907. To je godina kad Einstein uživa slavu otkrivši specijalnu teoriju relativnosti i odlučuje prihvatiti se novog zadatka: -- potpuno shvatiti gravitaciju, tu veliku silu koja prožima sve. U to doba mnogi ljudi misle da je taj zadatak već riješen. Newton je podario svijetu teoriju gravitacije krajem 17. stoljeća koja dobro funkcionira, objašnjava gibanje planeta, gibanje mjeseca, gibanje jabuka koje padaju sa stabala, udarajući ljude po glavi. Sve to se može opisati pomoću Newtonova djela.
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 Einstein je shvatio da je Newton izostavio nešto iz cijele priče, jer je čak i Newton napisao da iako je shvatio kako izračunati utjecaj gravitacije, nije uspio shvatiti kako ona ustvari funkcionira. Kako to da Sunce, udaljeno 150 milijuna km, nekako utječe na gibanje zemlje? Kako Sunce prodire kroz prazan i trom prostor i vrši utjecaj? I to je zadatak koji si je Einstein zadao -- shvatiti kako funkcionira gravitacija. Dopustite da vam pokažem što je otkrio. Einstein je otkrio da je sâm prostor medij koji prenosi gravitaciju. Ideja je sljedeća: zamislite da je prostor podloga 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.
Einstein kaže da je prostor ravan ako na njemu nema nikakve materije. Ali ako postoji materija u prostoru, kao što je Sunce, ona uzrokuje zakrivljenost prostora. I to prenosi silu gravitacije. Čak i Zemlja zakrivljuje prostor oko sebe. Sad pogledajte Mjesec. Prema ovoj teoriji, Mjesec ostaje u orbiti jer se kotrlja po udolini u zakrivljenom prostoru koju Sunce, Mjesec i Zemlja mogu stvoriti svojom prisutnošću. Sad pogledajmo cijelu sliku. Sama Zemlja ostaje u orbiti jer se kotrlja po udolini u prostoru koji je zakrivljen zbog Sunčeve prisutnosti. To je nova ideja kako ustvari djeluje gravitacija.
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.
Naime, ova ideja je testirana 1919. astronomskim opažanjima. Zaista djeluje. Opisuje opažanja. I time je Einstein stekao ugled diljem svijeta. I to je navelo Kaluzu na razmišljanje. On je, kao i Einstein, bio u potrazi za tzv. "objedinjenom teorijom". Radi se o teoriji koja bi sama mogla opisati sve prirodne sile pomoću jednog skupa ideja, jednog skupa principa, takoreći jedne glavne formule. Stoga je Kaluza zaključio, Einstein je uspio opisati gravitaciju u odnosu na uvijanje i zakrivljenje prostora -- točnije, prostora i vremena. Možda ja mogu napraviti isto s drugom poznatom silom, koja je u to vrijeme bila poznata kao elektromagnetska sila. Danas znamo i za druge, ali u ono doba to je bila jedina druga o kojoj su ljudi razmišljali. Znate, sila odgovorna za struju, magnetsku privlačnost i slično.
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.
I tako Kaluza kaže, možda i ja mogu napraviti isto i objasniti elektromagnetsku silu pomoću uvijanja i zakrivljenosti. To je postavilo pitanje uvijanje i krivljenje čega? Einstein je već iskoristio prostor i vrijeme, uvijanje i krivljenje, da opiše gravitaciju. Kao da nije ništa više ostalo za uvijanje i krivljenje. I tako Kaluza kaže, možda postoji više dimenzija prostora. Rekao je, ako želim opisati još jednu silu, možda mi treba još jedna dimenzija. Zamislio je da svijet ima četiri prostorne dimenzija, a ne tri, i da je elektromagnetizam uvijanje i krivljenje u toj četvrtoj dimenziji. Pazite sad ovo: kad je napisao formulu koja opisuje uvijanje i krivljenje u svemiru s četiri prostorne dimenzije, a ne tri, dobio je stare formule koje je Einstein već izveo u tri dimenzije -- za gravitaciju -- ali je dobio još jednu formulu zbog dodatne dimenzije. I kad je pogledao tu formulu, to nije bila ništa drugo nego formula za koju su znanstvenici već dugo znali da opisuje elektromagnetsku silu. Zadivljujuće -- samo se pojavila. Bio je toliko uzbuđen svojim otkrićem da je trčao oko kuće vičući "Pobjeda!" -- što je otkrio objedinjenu 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.
Naravno, Kaluza je bio čovjek koji vrlo ozbiljno shvaća teoriju. On, zapravo -- postoji priča da je, kad je htio naučiti plivati, pročitao knjigu, raspravu o plivanju -- (Smijeh) -- i zatim zaronio u ocean. On je čovjek koji bi riskirao svoj život prema teoriji. Ali za one među nama koji su više praktičnog uma, iz ovih promatranja odmah proizlaze dva pitanja. Prvo: ako je više dimenzija u prostoru, gdje su? Izgleda da ih ne vidimo. I drugo: djeluje li ova teorija doista precizno, kad ju primijenimo na svijet oko nas? Na prvo pitanje odgovor je dao 1926. mladić zvan Oskar Klein. On je iznio ideju da se dimenzije mogu pojavljivati u dvije varijante -- dimenzije mogu biti velike, lako vidljive, ali mogu biti i male, uvijene, uvijene tako sitno da ih, iako su svuda oko nas, ne možemo vidjeti.
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.
Dopustite da vam to prikažem vizualno. Zamislite da gledate u nešto kao kabel koji drži semafor. Nalazi se u Manhattanu. Vi ste u Central Parku -- nebitno je -- ali kabel izdaleka izgleda jednodimenzionalno, ali i vi i ja znamo da ima određenu debljinu. Koju je, doduše, teško vidjeti izdaleka. Ali ako se približimo i pogledamo iz perspektive, recimo, malog mrava koji hoda okolo -- mravi su tako mali da mogu pristupiti svim dimenzijama --- dimenziji dužine, ali također i smjeru kazaljke na satu i obrnuto. Nadam se da cijenite ovo. Dugo nam je trebalo da nagovorimo mrave da ovo izvedu.
(Laughter)
(Smijeh)
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 to ilustrira činjenicu da postoje dvije vrste dimenzija: velike i male. I ideju da su možda velike dimenzije oko nas one koje lako možemo vidjeti, ali da također postaje dodatne, uvrnute dimenzije, poput kružnog dijela kabela, tako sitne da su do sada bile nevidljive. Dopustite da vam pokažem kako bi to izgledalo. Ako pogledamo, recimo, prostore -- na ekranu mogu, naravno, prikazati samo dvije dimenzije. Neki od vas ovdje će riješiti taj problem jednog dana, ali sve što na ekranu nije ravno je nova dimenzija, postaje sve manja, i manja, i manja i u mikroskopskoj dubini samog prostora -- ovo je ideja: nalaze se dodatne, uvinute 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?
Evo jedne u obliku malog kruga -- tako je malen da ga ne možemo vidjeti. Ali da ste mikroskopski mrav koji hoda naokolo, mogli biste hodati u velikim dimenzijama koje svi znamo -- to je nešto kao rešetkasti dio -- ali mogli biste pristupiti i maloj, uvinutoj dimenziji koja je toliko sitna da je ne možemo vidjeti golim okom, pa čak ni našom najrazvijenijom opremom. Ali duboko u građi samog svemira, kao što smo vidjeli, ideja kaže da bi moglo postojati još dimenzija. Dakle, to je objašnjenje kako svemir može imati više dimenzija nego što ih vidimo. Ali što je s drugim pitanjem koje sam postavio: djeluje li teorija kad se primijeni na stvarni svijet?
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, pokazalo se da su Einstein i Kaluza i mnogi drugi pokušavali usavršiti ovaj idejni okvir i primijeniti ga na fiziku svemira kako je bila shvaćena u to doba, ali to nije funkcioniralo u detaljima. Na primjer, na razini detalja nisu uspjeli postići da masa elektrona točno funkcionira u ovoj teoriji. Mnogo ljudi je radilo na tome, ali do 40-ih, a svakako 50-ih godina ova čudna, ali vrlo privlačna ideja -- kako ujediniti zakone fizike -- je nestala. Dok se nije desilo nešto čudesno u naše doba. U našoj eri, novi pristup unificiranju zakona fizike razvijaju fizičari poput mene, i mnogi drugi diljem svijeta. Zove se teorija superstruna, kao što se dalo naslutiti. I ono što je predivno je da teorija superstruna na prvi pogleda nema nikakve veze s idejom o više dimenzija, ali kad proučavamo teoriju superstruna, otkrivamo da oživljuje tu ideju u blistavom novom ruhu.
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.
Stoga mi dopustite da vam kažem kako glasi. Teorija superstruna -- što je to? To je teorija koja pokušava odgovoriti na pitanje: što su osnovni, nedjeljivi, sastojci koji sačinjavaju sve na svijetu oko nas? Ideja je sljedeća. Zamislite da gledamo poznati predmet, svijeću u svijećnjaku, i zamislite da želimo otkriti od čega se sastoji. Stoga krenemo na putovanje duboko u taj predmet i proučimo njegov sastav. Svi znamo da, ako odemo dovoljno duboko, nalazimo atome. Znamo i to da atomi nisu kraj priče. Imaju male elektrone koji kruže oko centralne jezgre sastavljene od neutrona i protona. Čak i neutroni i protoni imaju u sebi sitnije čestice, kvarkove. I tu tradicionalne ideje završavaju.
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.
Evo nove ideje o teoriji struna. U dubini tih čestica, postoji još nešto. To nešto je žareća nit energije. Izgleda kao vibrirajuća struna -- odatle ideja o teoriji struna. I kao što vibrirajuće strune, koje ste upravo vidjeli kod čela, mogu vibrirati na različite načine, tako i ove mogu vibrirati po različitim uzorcima. One ne proizvode različite muzičke note, već različite čestice koje sačinjavaju svijet oko nas. Stoga, ako su ove ideje točne, ovako izgleda ultra mikroskopski krajolik svemira. Sastoji se od velikog broja malih, sitnih niti vibrirajuće energije, koje vibriraju na različitim frekvencijama. Različite frekvencije stvaraju različite čestice. Različite čestice su odgovorne za svo bogatstvo na svijetu 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 se vidi objedinjenost, jer čestice materije, elektroni i kvarkovi, radijacijske čestice, fotoni, gravitoni, svi su građeni od jednog jedinog entiteta. Stoga su sva materija i sve prirodne sile svrstane zajedno u skupinu vibrirajućih struna. I to smatramo objedinjenom teorijom. Međutim, postoji kvaka. Kad se proučava matematika teorije struna, pokazuje se da ne funkcionira u svemiru koji ima samo tri prostorne dimenzije. Ne funkcionira niti u svemiru sa četiri prostorne dimenzije, niti pet, niti šest. Na kraju, proučavanje formula pokazuje da funkcionira samo u svemiru koje ima 10 prostornih dimenzija i jednu vremensku. I to nas vodi natrag do Kaluzine i Kleinove ideje da naš svijet, ispravno opisan, 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.
Možete o tome razmišljati i reći, dobro, ako imamo dodatne dimenzija i one su čvrsto uvinute da, možda ih nećemo vidjeti ako su jako sitne. Ali ako postoji mala sitna civilizacija zelenih ljudi koja hoda tamo dolje, i ako su oni jako sitni, istina je, nećemo vidjeti ni njih. Jedno od drugih predviđanja teorije struna -- ne, to nije jedno od drugih predviđanja teorije struna.
(Laughter)
(Smijeh)
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: pokušavamo li samo sakriti te dodatne dimenzije, ili nam one nešto govore o svijetu? U preostalom vremenu htio bih vam predstaviti dva njihova svojstva. Kao prvo, mnogi među nama vjeruju da ove dodatne dimenzije sadrže odgovor na možda najozbiljnije pitanje teorijske fizike, teorijske znanosti. A to pitanje glasi: kad pogledamo uokolo po svijetu, kao što znanstvenici rade zadnjih sto godina, čini se da postoji nekih 20 brojeva koji uistinu opisuju svemir. To su brojevi poput mase čestica, poput elektrona i kvarka, jačine gravitacije, jačine elektromagnetske sile -- lista od dvadesetak brojeva koji su izmjereni s nevjerojatnom preciznošću, no nitko ne može objasniti zašto ti brojevi imaju baš tu vrijednost.
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.
Nudi li teorija struna odgovor? Ne još. Ali vjerujemo da bi odgovor na pitanje zašto ti brojevi imaju vrijednosti koje imaju mogao ovisiti o obliku dodatnih dimenzija. I čudesna činjenica je da kad bi ti brojevi imali neku drugu vrijednost od ovih znanih, svemir kakav poznajemo ne bi postojao. Ovo je ozbiljno pitanje. Zašto su ti brojevi tako fino podešeni da omogućuju zvijezdama da sjaje i planetima da nastaju, kad shvaćamo da ako se poigramo s tim brojevima -- kad bih ovdje imao 20 brojčanika i kad bih vam dao da smislite i poigrate se s tim brojevima, bilo kakvo poigravanje rezultiralo bi nestankom svemira. Dakle, možemo li objasniti tih 20 brojeva? Teorija struna sugerira da tih 20 brojeva ima veze s dodatnim dimenzijama. Dopustite da vam pokažem kako. Dakle, kad govorimo o dodatnim dimenzijama u teoriji struna, ne govorimo o jednoj dodatnoj dimenziji, kao u starim idejama Kaluze i Kleina. Evo što teorija struna kaže o dodatnim dimenzijama. Imaju bogato isprepletenu geometriju.
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 primjer nečeg poznatog pod nazivom "oblik Calabi-Yau", no ime i nije tako važno. Ali kao što možete vidjeti, dodatne dimenzije se savijaju same u sebe i isprepliću se u vrlo zanimljiv oblik, zanimljivu strukturu. Ideja je da ako dodatne dimenzije izgledaju ovako, onda bi mikroskopski krajolik svemira oko nas izgledao ovako u najsitnijem mjerilu. Kad zamahnete rukom, uvijek biste iznova prolazili kroz ove dodatne dimenzije, ali one su toliko male da toga ne biste bili svjesni. Koja je, dakle, fizikalna implikacija relevantna za tih 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.
Razmislite o ovome: ako pogledate instrument, francuski rog, vidjet ćete da vibracije zraka ovise o obliku instrumenta. U teoriji struna, svi brojevi su odrazi načina na koje strune mogu vibrirati. Dakle, kao što su i ta strujanja zraka ovisna o zakrivljenosti instrumenta, i same strune će ovisiti o vibrirajućim uzorcima u geometriji unutar koje se gibaju. Dopustite da unesem malo struna u priču, Ako pogledate ove male "momke" koji vibriraju uokolo -- sad će se pojaviti -- evo ovdje, pogledajte kako način na koji vibriraju ovisi o geometriji 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.
Stoga, kad bismo točno znali kako te dodatne dimenzije izgledaju -- još ne znamo, ali kad bismo znali -- trebali bismo moći izračunati dozvoljene note, dozvoljene uzorke vibriranja. A kad bismo mogli izračunati dozvoljene uzorke vibriranja, trebali bismo biti u stanju izračunati onih 20 brojeva. I ako se rezultati koje dobijemo iz naših proračuna slažu s vrijednostima tih brojeva, koje su određene detaljnim i preciznim eksperimentiranjem, to bi na mnoge načine bilo prvo fundamentalno objašnjenje zašto je struktura svemira onakva kakva je. Nadalje, drugi problem, s kojim bih htio zaključiti, je: kako bismo izravnije mogli testirati postojanje dodatnih dimenzija? Je li to samo zanimljiva matematička struktura koja bi mogla objasniti prethodno neobjašnjiva svojstva svijeta, ili stvarno možemo testirati postojanje tih dodatnih dimenzija? Mislimo -- i ovo je, po mom mišljenju, vrlo uzbudljivo -- da bismo u sljedećih pet godina, ili tu negdje, mogli provjeriti 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.
to izgleda. U CERN-u, u Ženevi, u Švicarskoj, gradi se stroj nazvan veliki hadronski sudarač. To je uređaj koji će poslati čestice duž kružnog tunela, u obrnutim smjerovima, brzinom bliskom brzini svjetlosti. Svako malo čestice će biti usmjerene jedna prema drugoj tako da dođe do izravnog sudara. Ako sudar stvori dovoljno energije, možda izbaci neke ostatke sudara iz naših dimenzija i natjera ih da uđu u druge dimenzije. Kako ćemo to znati? Pa, izmjerit ćemo količinu energije nakon sudara, usporediti je s količinom prije, i ako nakon sudara energije bude manje nego prije to će biti dokaz da je energija nekamo otišla. I ako ode u pravom uzorku koji možemo izračunati, to će biti dokaz da postoje dodatne dimenzije.
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.
Dopustite da vam pokažem tu ideju vizualno. Zamislite da imamo određenu česticu zvanu graviton -- to je ostatak kakav očekujemo da bude izbačen ako dodatne dimenzije postoje. Evo kako bi eksperiment izgledao. Uzmete ove čestice. Međusobno ih sudarite. I, ako smo u pravu, nešto energije od sudara će otići u ostatak koji odleti u dodatne dimenzije. Dakle to je tip eksperimenta koji ćemo provoditi u sljedećih pet, sedam do 10 godina ili tu negdje. I ako ovaj eksperiment urodi plodom, ako budemo vidjeli izbacivanje takve čestice jer će biti manje energije u našoj dimenziji nego prije početka, pokazat će se da dodatne dimenzija stvarno 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 to stvarno izvanredna priča i izvanredna prilika. Vraćanje Newtonu s apsolutnim prostorom -- nije pružilo ništa osim pozornice na kojoj se odvijaju događaji svemira. Dolazi Einstein i kaže: prostor i vrijeme se mogu uvijati i kriviti, to je gravitacija. A sad dolazi teorija struna i kaže: da, gravitacija, kvantna mehanika, elektromagnetizam -- sve je zajedno u jednom paketu, ali samo ako svemir ima više dimenzija nego što ih vidimo. Ovo je eksperiment koji bi to mogao provjeriti u toku našeg života. Čudesne mogućnosti. Hvala puno.
(Applause)
(Pljesak)