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.
Leta 1919 je skoraj neznan nemški matematik Theodor Kaluza predlagal zelo drzno in dokaj nenavadno zamisel. Predpostavil je, da bi lahko naše vesolje v resnici imelo več kot tri dimenzije, ki se jih zavedamo. Torej, smerem levo-desno, nazaj-naprej in gor-dol, je Kaluza dodal možne dimenzije prostora, ki jih zaenkrat iz različnih razlogov še ne opazimo. Če se pojavi drzna in nenavadna zamisel, je včasih ta samo drzna in nenavadna, nima pa nič skupnega z resničnim svetom. Vendar je ta zamisel, o kateri govorim, čeprav še ne vemo zagotovo, če drži ali ne, in na koncu bom povedal o eksperimentih, ki nam lahko čez nekaj let povedo, če drži ali ne, ta zamisel je močno vplivala na razvoj fizike v prejšnjem stoletju in tudi zdaj navdihuje veliko vodilnih raziskav.
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.
Torej, rad bi vam povedal zgodbo o teh dodatnih dimenzijah. Kam se naj obrnemo? Za začetek potrebujemo uvod. Gremo v 1907. To je letnica, ko Einstein počiva na lovorikah, ker je odkril posebno teorijo relativnosti, in se odloči sprejeti nov izziv - poskusil bo popolnoma razumeti veliko, prodorno silo gravitacije. V tistem času je bilo veliko ljudi, ki so menili, da je ta projekt že rešen. Newton je v poznem 16. stoletju dal svetu teorijo gravitacije, ki dela dobro: opisuje gibanje planetov, gibanje Lune, in tako dalje, razlaga padec legendarnih jabolk z dreves ljudem na glave. In vse to je moč opisati s pomočjo Newtonovega dela. Ampak Einstein je ugotovil, da je Newton pustil nekaj ob strani,
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.
saj je Newton celo zapisal, da ni, čeprav je razumel, kako naj bi izračunal učinek gravitacije, nikakor mogel ugotoviti, kako zares deluje. Kako je mogoče, da Sonce, 150 milijonov kilometrov daleč, nekako vpliva na gibanje Zemlje? Kako Sonce vpliva skozi ta prazen, nedejaven prostor? In to je bila naloga, ki si jo je Einstein zadal - ugotoviti, kako deluje gravitacija. Naj vam pokažem, kaj je našel. Einstein je ugotovil, da je posrednik gravitacije sam prostor. Zamisel je taka: predstavljajte si, da je prostor temelj za vse, kar je.
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 je rekel, da je prostor brez snovi raven. Kadar pa v okolju snov je, denimo Sonce, povzroči, da se tkanina prostora zvije in ukrivi. In to prenaša silo gravitacije. Celo Zemlja ukrivi prostor okoli sebe. Poglejmo zdaj Luno. Luna vztraja v skladu s temi zamislimi v svoji orbiti zato, ker kroži po dolini ukrivljenega območja, ki ga s svojo prisotnostjo ustvarijo Sonce, Luna in Zemlja. Poglejmo zdaj veliko sliko. Tudi Zemlja sama se zadržuje v orbiti, ker kroži po območju, ki je ukrivljeno zaradi prisotnosti Sonca. To je nova zamisel o tem, kako gravitacija deluje.
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.
To teorijo so leta 1919 potrdili z astronomskimi opazovanji. Res dela. Opisuje podatke. Z njo se je Einstein uveljavil v svetu. Prav ta teorija je dala Kaluzi misliti. Kot Einstein je tudi on poskušal najti tisto, čemur se reče "poenotena teorija". To je ena teorija, ki bi opisovala vse naravne sile z enim naborom zamisli, z enim naborom načel, z eno ključno enačbo, če hočete. Kaluza si je rekel: Einsteinu se je posrečilo opisati gravitacijo z zvitostjo in ukrivljenostjo prostora - v resnici, bolj natančno, prostora in časa. Mogoče bi lahko storil enako s tisto drugo znano silo, takrat znano kot elektromagnetna sila - dandanes poznamo tudi druge, a tedaj je bila to edina druga sila, o kateri so ljudje razmišljali. Sila, pristojna za elektriko ter magnetno privlačnost, in tako naprej.
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.
Kaluza je rekel, lahko bi naredil enako in opisal elektromagnetno silo kot zvitja in ukrivljenosti. Tu se je postavilo vprašanje: zvitja in ukrivljenosti v čem? Einstein je že porabil prostor in čas, zvitja in ukrivljenosti, da je opisal gravitacijo. Ni bilo videti, da bi se dalo še kaj zvijati ali ukrivljati. Zato je Kaluza rekel: no, mogoče pa obstaja več prostorskih razsežnosti. Rekel je: če hočem opisovati še eno silo, morda potrebujem še eno razsežnost. Zato si je zamislil, da ima svet štiri dimenzije, ne tri, in si je zamislil, da je elektromagnetizem zvijanje in ukrivljanje v tej četrti dimenziji. Zanimivo je pa to: ko je zapisal enačbe, ki so opisovale zvijanje in ukrivljanje v vesolju s štirimi prostorskimi dimenzijami, ne tremi, je našel stare enačbe, ki jih je Einstein že izpeljal v treh dimenzijah - te so bile za gravitacijo - pa še eno enačbo zaradi dodatne dimenzije. In ko je pogledal to enačbo, je bila to ravno tista enačba, za katero so znanstveniki že dolgo vedeli, da opisuje elektromagnetno silo. Neverjetno - kar skočila je ven. Tako je bil navdušen nad tem spoznanjem, da je začel tekati po hiši in kričati: "Zmaga!" - ker naj bi našel poenoteno teorijo.
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.
Očitno je, da je Kaluza bil človek, ki je teorijo jemal zelo resno. On je v bistvu - znana je zgodba o tem, da je, ko se je hotel naučiti plavati, prebral knjigo, razpravo o plavanju - (Smeh) - potem pa skočil v ocean. Ta človek bi tvegal življenje na podlagi teorije. A za tiste med nami, ki smo malo bolj praktičnega uma, se takoj zastavita dve vprašanji glede njegovega opažanja. Prvo: če je v prostoru več dimenzij, kje pa so? Kaže, da jih ne vidimo. In drugo: ali ta teorija res drži v potankostih, ko jo poskusiš uporabiti za opis sveta okoli nas? Odgovor na prvo vprašanje je leta 1926 našel mož, ki se je imenoval Oskar Klein. Predpostavil je, da obstajata dve vrsti razsežnosti - utegnejo biti velike in lahko opazne dimenzije, utegnejo pa biti tudi majcene, skodrane dimenzije, skodrane tako močno, da tudi če so vse naokrog nas, jih ne moremo videti.
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.
Naj vam to pokažem. Predstavljajte si, da gledate kabel, ki podpira semafor. To je Manhattan. Ste v Centralnem parku - kar niti ni važno - a kabel je od daleč videti enodimenzionalen, a mi vsi vemo, da ima neko debelino. No, zelo težko jo je videti od daleč. Če se približamo in pogledamo iz perspektive, denimo, majhne mravlje, ki se sprehaja naokoli - majhne mravlje so tako majhne, da pridejo do vseh dimenzij - do podolžne dimenzije, pa tudi do obeh smeri po obsegu. Upam, da to cenite. Mravlje smo res dolgo pripravljali do tega. (Smeh)
(Laughter)
To ponazarja dejstvo, da so dimenzije lahko dveh vrst: velike in male.
But this illustrates the fact that dimensions can be of two sorts: big and small. And the idea that maybe the big dimensions around us 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 --
In misel, da so morda velike dimenzije okrog nas tiste, ki jih z lahkoto vidimo, da pa so morda dodatne dimenzije skodrane, tako kot obseg tega kabla, tako majhne, da so doslej ostale nevidne. Naj vam pokažem, kako bi to izgledalo. Če zdaj pogledamo, recimo, na prostor sam - seveda lahko prikažem le dve dimenziji na zaslonu. Nekdo bo nekega dne to popravil, zaenkrat pa je vse, kar na zaslonu ni ravno, nova dimenzija, ki se manjša še in še in še, vse do mikroskopskih globin prostora samega, to je zamisel, lahko bi imel dodatne skodrane 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?
Tu je majhna oblika kroga - tako so majhne, da jih ne vidimo. A če bi vi bili ultramikroskopsko majcene mravlje, ki bi se sprehajale naokoli, bi se sprehodili v znanih velikih dimenzijah - tukaj kot mreža - a bi dosegali tudi majcene skodrane dimenzije, ki so tako majhne, da jih ne vidimo ne s prostim očesom, ne z nobeno najbolj izpopolnjeno opremo. Toda globoko spodvihana v tkanino prostora samega, je zamisel, da bi lahko bilo več dimenzij, kar vidimo tukaj. No, to je razlaga o tem, kako bi vesolje lahko imelo več dimenzij, kot jih vidimo. Kaj pa drugo vprašanje, ki sem ga postavil: ali ta teorija dejansko deluje, ko jo poskusiš uporabiti v resničnem svetu?
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.
Izkazalo se je, da so Einstein, Kaluza in mnogo drugih poskušali izpopolniti ta okvir in ga uporabiti v fiziki vesolja, kot so jo takrat razumeli, in v podrobnostih ni delovala. Ena podrobnost, na primer, po tej teoriji se jim izračuni za maso elektrona niso izšli prav. Ogromno ljudi je delalo na tem, ampak v 40-ih in zagotovo v 50-ih je ta nenavadna, a zelo privlačna zamisel, kako poenotiti zakone fizike, že izginila. Dokler se ni nekaj prelepega zgodilo v naši dobi. Nov pristop k poenotenju fizikalnih zakonov v našem času, ki mu sledimo fiziki, vključno z mano ter mnogimi drugimi po svetu. se imenuje teorija superstrun, kot ste nakazovali. Najlepše je to, da teorija superstrun na prvi pogled nima nič skupnega z zamislijo o dodatnih dimenzijah, A ko preučujemo teorijo superstrun, ugotovimo, da oživi to zamisel v iskrivi, novi obliki.
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.
Naj vam povem, kako to gre. Teorija superstrun - kaj je to? To je teorija, ki skuša odgovoriti na vprašanje: kaj so osnovni, temeljni, nedeljivi, nerazrezljivi sestavni deli, ki sestavljajo vse na svetu okoli nas? Zamisel je taka. Predstavljajte si, da gledamo znan predmet, svečo v svečniku, in predstavljajte si, da želimo ugotoviti, iz česa je narejena. Odpotujmo v globine predmeta in si oglejmo sestavne delce. Globoko znotraj - vsi vemo, če greš dovolj globoko, prideš do atomov. Vemo tudi, da atomi še niso konec zgodbe. Imajo majhne elektrone, ki rojijo okrog jedra v sredi, z nevtroni in protoni. Celo nevtroni in protoni vsebujejo manjše delce, ki so znani kot kvarki. Tu se običajne zamisli končajo.
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.
Tu pa je nova zamisel teorije strun. Globoko v vseh teh delcih je še nekaj drugega. Tisto nekaj drugega je poplesujoča nit energije., Izgleda kot struna, ki trepeče - od tod prihaja zamisel, teorija strun. Tako kot lahko nihajoče strune, ki ste jih videli na čelu, nihajo po različnih vzorcih, lahko tudi te nihajo po različnih vzorcih. Ne ustvarjajo različnih tonov, temveč ustvarjajo različne delce, ki sestavljajo svet okoli nas. Če so te zamisli pravilne, je ultra-mikroskopska pokrajina vesolja videti tako. Zgrajena je iz velikanskega števila teh majcenih niti nihajoče energije, ki nihajo na različnih frekvencah. Različne frekvence ustvarjajo različne delce. Različni delci so odgovorni za vsa bogastva v svetu okoli 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.
V tem vidiš poenotenje, saj so snovni delci, elektroni in kvarki, delci sevanja, fotoni, gravitoni, vsi zgrajeni iz istega bistva. Tako so snov in sile narave povezane pod rubriko nihajočih strun. In to je mišljeno s poenoteno teorijo. Pojavi pa se zagata. Ko preučuješ matematiko teorije strun, odkriješ, da teorija ne deluje v vesolju, ki ima le tri razsežnosti. Ne dela niti v vesolju s štirimi, petimi ali šestimi dimenzijami. Končno, lahko proučuješ enačbe in pokažeš, da delujejo v vesolju, ki ima 10 prostorskih razsežnosti in eno časovno. To nas pripelje nazaj k zamisli Kaluze in Kleina, da ima naš svet, ko je ustrezno opisan, več dimenzij, kot jih 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.
To lahko premisliš in reče, no, prav, veste, če imaš dodatne dimenzije, in če so res na tesno skodrane, gotovo, najbrž jih ne bomo videli, če so dovolj majhne. A če se sprehaja tam spodaj drobcena civilizacija zelenih človečkov, in jih narediš dovolj majhne, tudi njih ne bomo videli. To je res. Ena od drugih napovedi teorije strun - ne, ni to ena od drugih napovedi teorije strun.
(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.
Postavlja pa vprašanje: ali le poskušamo skriti te dodatne dimenzije, ali pa nam povedo kaj o svetu? V času, ki preostane, bi rad pojasnil dve njihovi značilnosti. Prva je, mnogi verjamemo, da te dodatne dimenzije skrivajo odgovor na verjetno najgloblje vprašanje v teoretični fiziki, v teoretični znanosti. In vprašanje je: ko se oziramo po svetu, kot so se znanstveniki zadnje stoletje, kaže, da 20 številk dobro opiše naše vesolje. To so številke, kot mase delcev, denimo elektronov in kvarkov, moč gravitacije, moč elektromagnetnih sil - seznam približno 20 številk, ki so bile izmerjene neverjetno natančno, a nihče ne zna razložiti, zakaj imajo številke take vrednosti, kot jih imajo.
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.
Zdaj, ali teorija strun ponuja odgovor? Še ne. A verjamemo, da odgovor, zakaj so številke take, kot so, morda zavisi od oblike dodatnih dimenzij. In lepo je to, da če bi imele te številke vrednosti drugačne, kot jih poznamo, vesolja, kot ga poznamo, ne bi bilo. To je globoko vprašanje. Zakaj so te številke tako dobro uglašene, da omogočajo, da zvezde sijejo in se planeti tvorijo, ko razumemo, da če se igračkaš s temi številkami - če bi imel tu gori 20 številčnic in bi pustil, da se pridete igračkat, bi skoraj vsaka sprememba povzročila, da vesolje izgine. Ali lahko pojasnimo teh 20 številk? Teorija strun kaže, da je teh 20 številk povezanih z dodatnimi dimenzijami. Naj vam pokažem, kako. Torej, ko govorimo o dodatnih razsežnostih v teoriji strun, to ni ena dodatna razsežnost, kot v starih zamislih Kaluze in Kleina. To govori teorija strun o dodatnih dimenzijah. Imajo zelo bogato, prepleteno geometrijo.
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?
To je primer nečesa, kar je znano kot oblika Calabi-Yau - ime ni tako pomembno. Vendar, kot vidite, se dodatne dimenzije zvijajo vase in se prepletajo v zelo zanimive oblike, v zanimivo strukturo. In zamisel je, da če tako izgledajo dodatne dimenzije, potem bi bila mikroskopska pokrajina našega vesolja vse okoli nas videti takole na najmanjših lestvicah. Ko zamahneš z roko, bi se kar naprej pomikal okoli teh dodatnih razsežnosti, a so tako majhne, da tega ne bi vedel. Kaj pa je potem fizikalna posledica, povezana s temi 20 številkami?
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 tem. Če pogledate instrument, francoski rog, opazite, da so nihanja zračnih tokov odvisna od oblike instrumenta. V teoriji strun so vse številke odraz načina, kako strune lahko nihajo. Prav tako, kot na zračne tokove vplivajo zavoji in obrati v instrumentu, bodo na strune same vplivali vzorci nihanj v geometriji, v kateri se gibljejo. Naj vnesem nekaj strun v zgodbo. In če gledate te male stvarce, kako vibrirajo naokoli - vsak hip bodo tu - so že, boste opazili, da so načini, kako vibrirajo, odvisni od geometrije dodatnih dimenzij.
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.
Torej, če bi vedeli, kako dodatne dimenzije izgledajo - mi še ne, ampak če bi - bi morali biti sposobni, da izračunamo dovoljene tone, dovoljene vzorce nihanja. In če bi lahko izračunali dovoljene vzorce nihanja, bi morali biti sposobni izračunati teh 20 številk. In če bi se odgovor, dobljen z našimi izračuni ujemal z vrednostmi teh številk, ki so bile določene s podrobnim in natančnim eksperimentiranjem, bi to v mnogih pogledih bila prva temeljna razlaga, zakaj je struktura vesolja taka, kot je. Zdaj, druga zadeva, ki jo želim dodelati je: kako bi lahko testirali te dodatne razsežnosti bolj neposredno? Ali je to le zanimiva matematična struktura, ki bi lahko pojasnila nekatere prej nepojasnjene značilnosti sveta, ali lahko dejansko preverimo te dodatne razsežnosti? In mislimo - in to je, mislim, zelo razburljivo - da bomo v naslednjih petih letih ali kaj takega lahko preverili obstoj teh dodatnih dimenzij.
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.
Tako bo to šlo. V CERN-u, Ženeva, Švica, gradijo stroj, ki se imenuje Veliki hadronski trkalnik. To je stroj, ki bo poslal delce po krožnem predoru, v nasprotnih smereh, blizu svetlobne hitrosti. Vsake toliko časa bodo ti delci usmerjeni drug proti drugemu, tako da se bodo čelno trčili. Upati je, da če bodo imela trčenja dovolj energije, da bo izvrglo nekaj ostankov trka iz naših dimenzij v druge dimenzije. Kako bi to vedeli? No, izmerili bomo količino energije po trčenju, jo primerjali s količino energije prej, in če je energije po trčenju manj kot prej, bo to dokaz, da je energija odšla drugam. Če bo odšla tako, da bomo to lahko izračunali, bo to dokaz, da dodatne dimenzije so.
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.
Naj vam pokažem to zamisel vizualno. Imamo določeno vrsto delca, ki se imenuje graviton - to pa je vrsta razbitin, za katere pričakujemo, da se izvržejo, če dodatne dimenzije res so. Tu je, kako bo poskus potekal. Vzameš te delce. Treščiš jih skupaj. Treščiš jih skupaj, in če smo imeli prav, bo nekaj energije tega trka šlo v razbitine, ki odletijo v dodatne dimenzije. To je torej take vrste eksperiment, na katerega bomo pozorni naslednjih pet, sedem do 10 let ali kaj takega. In če bo ta poskus obrodil sadove, če opazimo, da je bil izvržen tak delec, da obstaja manj energije v naših dimenzijah, kot na začetku, to bo dokazalo, da dodatne dimenzije obstajajo.
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.
In zame je to res izjemna zgodba in izjemna priložnost. Če se vrnemo k Newtonu z absolutnim prostorom - ni zagotovil nič, samo areno, oder, kjer dogodki v vesolju potekajo. Pa pride Einstein in pravi, v redu, prostor in čas se lahko zvijata in krivita - to je gravitacija. Pa pride zdaj še teorija strun in pravi, seveda, gravitacija, kvantna mehanika, elektromagnetizem, vse skupaj v enem paketu, a le, če je v vesolju več dimenzij, kot je tistih, ki jih vidimo. In to je poskus, ki to lahko preizkusi za našega življenja. Neverjetna možnost. Najlepša hvala.
(Applause)
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