Sean Carroll: Distant time and the hint of a multiverse

Prevoditelj: Janko Mihelić Recezent: Tilen Pigac - EFZG

The universe

Svemir

is really big.

je jako velik.

We live in a galaxy, the Milky Way Galaxy.

Živimo u galaksiji Mliječni put.

There are about a hundred billion stars in the Milky Way Galaxy.

U njoj ima oko sto milijardi zvijezda.

And if you take a camera

Ako uzmete kameru

and you point it at a random part of the sky,

i uperite je u nasumični komad neba,

and you just keep the shutter open,

i ostavite zatvarač otvorenim,

as long as your camera is attached to the Hubble Space Telescope,

i ako vam je kamera spojena na teleskop Hubble,

it will see something like this.

vidjet će ovakvo nešto.

Every one of these little blobs

Svaka mrlja je galaksija

is a galaxy roughly the size of our Milky Way --

veličine Mliječnog puta --

a hundred billion stars in each of those blobs.

u svakoj oko sto milijardi zvijezda.

There are approximately a hundred billion galaxies

Postoji oko sto milijardi galaksija

in the observable universe.

u vidljivom svemiru.

100 billion is the only number you need to know.

Sto milijardi je jedini broj.

The age of the universe, between now and the Big Bang,

Starost Svemira, od sad do Velikog Praska,

is a hundred billion in dog years.

je sto milijardi u psećim godinama.

(Laughter)

(Smijeh)

Which tells you something about our place in the universe.

Što vam govori nešto o našem značaju u svemiru.

One thing you can do with a picture like this is simply admire it.

Ovoj slici se divimo.

It's extremely beautiful.

Jako je lijepa.

I've often wondered, what is the evolutionary pressure

Pitao sam se, kakav evolucijski pritisak

that made our ancestors in the Veldt adapt and evolve

je natjerao naše pretke u Veldt ravnicama da evoluiraju

to really enjoy pictures of galaxies

da im se sviđaju slike galaksija

when they didn't have any.

dok ih nisu imali.

But we would also like to understand it.

Ali ih želimo razumjeti.

As a cosmologist, I want to ask, why is the universe like this?

Kao kozmolog se pitam, zašto je svemir ovakav?

One big clue we have is that the universe is changing with time.

Veliki trag je da se svemir mijenja s vremenom.

If you looked at one of these galaxies and measured its velocity,

Ako gledate jednu galaksiju, i mjerite joj brzinu,

it would be moving away from you.

ona se kreće od vas.

And if you look at a galaxy even farther away,

Ako gledate još dalju galaksiju

it would be moving away faster.

ona se kreće još brže.

So we say the universe is expanding.

Zato kažemo da se svemir širi.

What that means, of course, is that, in the past,

To znači da su u prošlosti

things were closer together.

stvari bile međusobno bliže.

In the past, the universe was more dense,

U prošlosti je svemir bio gušći,

and it was also hotter.

i topliji.

If you squeeze things together, the temperature goes up.

Ako nešto stisneš, temperatura raste.

That kind of makes sense to us.

To ima smisla.

The thing that doesn't make sense to us as much

Ono što nema smisla

is that the universe, at early times, near the Big Bang,

je da je svemir, jako rano, blizu Velikog Praska,

was also very, very smooth.

bio jako gladak.

You might think that that's not a surprise.

To nije iznenađujuće.

The air in this room is very smooth.

Zrak u ovoj sobi je jako gladak.

You might say, "Well, maybe things just smoothed themselves out."

Kažete, "Možda su se stvari izgladile."

But the conditions near the Big Bang are very, very different

Ali uvjeti blizu Velikog Praska su puno drugačiji

than the conditions of the air in this room.

nego uvjeti zraka u ovoj sobi.

In particular, things were a lot denser.

Stvari su bile puno gušće.

The gravitational pull of things

Gravitacijska privlačnost

was a lot stronger near the Big Bang.

je bila jaka blizu Velikog Praska.

What you have to think about

Morate znati

is we have a universe with a hundred billion galaxies,

da imamo svemir sa sto milijardi galaksija,

a hundred billion stars each.

svaka sa sto milijardi zvijeda.

At early times, those hundred billion galaxies

U rana vremena, tih sto milijardi galaksija

were squeezed into a region about this big --

je bilo stješnjeno

literally -- at early times.

u ovoliki prostor.

And you have to imagine doing that squeezing

Zamislite to stješnjavanje

without any imperfections,

bez ikakvih nesavršenosti,

without any little spots

bez ikakvih točkica

where there were a few more atoms than somewhere else.

s više atoma nego drugdje.

Because if there had been, they would have collapsed under the gravitational pull

Jer da je bilo, sve bi se urušilo zbog gravitacije

into a huge black hole.

u veliku crnu rupu.

Keeping the universe very, very smooth at early times

Držanje svemira vrlo glatkim tako rano

is not easy; it's a delicate arrangement.

nije lako, to je osjetljiv raspored.

It's a clue

To je indicija

that the early universe is not chosen randomly.

da rani svemir nije odabran slučajno.

There is something that made it that way.

Nešto ga je takvim napravilo.

We would like to know what.

Željeli bi znati što.

So part of our understanding of this was given to us by Ludwig Boltzmann,

Dio shvaćanja ovoga nam je dao Ludwig Boltzmann,

an Austrian physicist in the 19th century.

Austrijski fizičar 19. stoljeća.

And Boltzmann's contribution was that he helped us understand entropy.

Boltzmanov doprinos je bio shvaćanje entropije.

You've heard of entropy.

Čuli ste za entropiju.

It's the randomness, the disorder, the chaoticness of some systems.

To je slučajnost, nered, kaotičnost sistema.

Boltzmann gave us a formula --

Boltzmann nam je dao formulu --

engraved on his tombstone now --

ugraviranu na njegov nadgrobni kamen --

that really quantifies what entropy is.

koja kvantificira entropiju.

And it's basically just saying

I ona kaže

that entropy is the number of ways

da je entropija suma načina na koji

we can rearrange the constituents of a system so that you don't notice,

možemo preurediti sustav da se to ne primjeti,

so that macroscopically it looks the same.

da makroskopski izgleda jednako.

If you have the air in this room,

Imamo zrak u ovoj sobi,

you don't notice each individual atom.

ne primjećujete zasebne atome.

A low entropy configuration

Kod konfiguracije niske entropije

is one in which there's only a few arrangements that look that way.

imamo tek nekoliko razmještaja koji izgledaju jednako.

A high entropy arrangement

Kod visoke entropije

is one that there are many arrangements that look that way.

imamo puno razmještaja koji izgledaju jednako.

This is a crucially important insight

Ovo je presudno važan uvid,

because it helps us explain

jer nam objašnjava

the second law of thermodynamics --

drugi zakon termodinamike --

the law that says that entropy increases in the universe,

zakon koji kaže da se entropija povećava u svemiru,

or in some isolated bit of the universe.

ili u izoliranom dijelu svemira.

The reason why entropy increases

Entropija se povećava

is simply because there are many more ways

jer ima puno više načina

to be high entropy than to be low entropy.

da budeš visoke nego niske entropije.

That's a wonderful insight,

Ovo je divan uvid,

but it leaves something out.

ali nešto izostavlja.

This insight that entropy increases, by the way,

Ovo mišljenje da se entropija povećava,

is what's behind what we call the arrow of time,

stoji iza vremenskog pravca,

the difference between the past and the future.

razlike između prošlosti i budućnosti.

Every difference that there is

Svaka promjena koja postoji

between the past and the future

između prošlosti i budućnosti

is because entropy is increasing --

jest uslijed povećanja entropije --

the fact that you can remember the past, but not the future.

činjenica da se možemo sjetiti prošlosti, a ne budućnosti.

The fact that you are born, and then you live, and then you die,

Činjenica da ste rođeni, pa živite, i onda umrete,

always in that order,

uvijek u tom slijedu,

that's because entropy is increasing.

jest zbog povećavajuće entropije.

Boltzmann explained that if you start with low entropy,

Boltzmann je objasnio da ako počnete s malom entropijom,

it's very natural for it to increase

prirodno je da se povećava,

because there's more ways to be high entropy.

jer postoji više načina da bude visoka entropija.

What he didn't explain

Ono što nije objasnio

was why the entropy was ever low in the first place.

jest zašto je entropija na početku bila niska.

The fact that the entropy of the universe was low

Ta činjenica

was a reflection of the fact

ogledava činjenicu

that the early universe was very, very smooth.

da je rani svemir bio gladak.

We'd like to understand that.

Želimo to razumjeti.

That's our job as cosmologists.

To je posao kozmologa.

Unfortunately, it's actually not a problem

Tom problemu

that we've been giving enough attention to.

nismo davali dosta pažnje.

It's not one of the first things people would say,

To nije stvar koju bi prvu rekao

if you asked a modern cosmologist,

da ste pitali kozmologa

"What are the problems we're trying to address?"

"Koje probleme pokušavate rješiti?"

One of the people who did understand that this was a problem

Jedan od ljudi koji su to razumjeli

was Richard Feynman.

bio je Richard Feynman.

50 years ago, he gave a series of a bunch of different lectures.

Prije 50 godina, dao je niz predavanja.

He gave the popular lectures

Popularna predavanja

that became "The Character of Physical Law."

koja su postala "Osobitosti fizikalnih zakona."

He gave lectures to Caltech undergrads

Davao je predavanja studentima Caltecha

that became "The Feynman Lectures on Physics."

koja su postala "Feynmanova predavanja o fizici."

He gave lectures to Caltech graduate students

Davao je predavanja diplomcima

that became "The Feynman Lectures on Gravitation."

koja su postala "Feynmanova predavanja o gravitaciji."

In every one of these books, every one of these sets of lectures,

I u svakom predavanju

he emphasized this puzzle:

naglašavao je zagonetku:

Why did the early universe have such a small entropy?

Zašto je rani svemir imao malu entropiju?

So he says -- I'm not going to do the accent --

Pa kaže -- neću imitirati naglasak --

he says, "For some reason, the universe, at one time,

kaže, "Iz nekog razloga je svemir,

had a very low entropy for its energy content,

imao malu entropiju za istu količinu energije,

and since then the entropy has increased.

i entropija se povećavala.

The arrow of time cannot be completely understood

Pravac vremena se ne može shvatiti

until the mystery of the beginnings of the history of the universe

dok se misterij početaka povijesti svemira

are reduced still further

ne svede s nagađanja

from speculation to understanding."

na razumjevanje."

So that's our job.

To je naš posao.

We want to know -- this is 50 years ago, "Surely," you're thinking,

To je bilo prije 50 godina, mislite

"we've figured it out by now."

"sigurno smo to već shvatili."

It's not true that we've figured it out by now.

Još nismo shvatili.

The reason the problem has gotten worse,

Razlog zašto se problem

rather than better,

još pogoršao

is because in 1998

je zato što smo 1998.

we learned something crucial about the universe that we didn't know before.

naučili nešto presudno o svemiru.

We learned that it's accelerating.

Naučili smo da se ubrzava.

The universe is not only expanding.

Ne samo to.

If you look at the galaxy, it's moving away.

Galaksije se odmiču.

If you come back a billion years later and look at it again,

Nakon milijardu godina opet pogledaš,

it will be moving away faster.

odmiču se još brže.

Individual galaxies are speeding away from us faster and faster

Galaksije se odmiču sve brže i brže.

so we say the universe is accelerating.

Kažemo da se svemir ubrzava.

Unlike the low entropy of the early universe,

Za razliku od male entropije ranog svemira,

even though we don't know the answer for this,

makar ne znamo odgovor na to,

we at least have a good theory that can explain it,

imamo dobru teoriju koja to objašnjava,

if that theory is right,

ako je točna

and that's the theory of dark energy.

a to je teorija tamne energije.

It's just the idea that empty space itself has energy.

Kaže da prazan prostor ima energiju.

In every little cubic centimeter of space,

U svakom kubičnom centimetru,

whether or not there's stuff,

bilo ili ne bilo stvari,

whether or not there's particles, matter, radiation or whatever,

čestica, materije, zračenja, svejedno,

there's still energy, even in the space itself.

ima energije, u samom prostoru.

And this energy, according to Einstein,

Ova energija, po Einsteinu,

exerts a push on the universe.

vrši guranje na svemir.

It is a perpetual impulse

To je neprekidan impuls

that pushes galaxies apart from each other.

koji gura galaksije jednu od druge.

Because dark energy, unlike matter or radiation,

Tamna energija se, za razliku od materije ili zračenja,

does not dilute away as the universe expands.

ne razrjeđuje kako se svemir širi.

The amount of energy in each cubic centimeter

Količina energije u svakom kubičnom centimetru

remains the same,

ostaje ista,

even as the universe gets bigger and bigger.

kako se svemir povećava.

This has crucial implications

Ovo ima presudne implikacije

for what the universe is going to do in the future.

na to što će svemir napraviti u budućnosti.

For one thing, the universe will expand forever.

Kao prvo, svemir će se širiti zauvijek.

Back when I was your age,

Kad sam bio vaših godina,

we didn't know what the universe was going to do.

nismo znali što će svemir napraviti.

Some people thought that the universe would recollapse in the future.

Neki su mislili da će se svemir u budućnosti sažeti.

Einstein was fond of this idea.

Einsteinu se sviđala ova ideja.

But if there's dark energy, and the dark energy does not go away,

Ali ako imamo tamnu energiju, i ona ne odlazi,

the universe is just going to keep expanding forever and ever and ever.

svemir će se širiti sve više.

14 billion years in the past,

Prošlih 14 milijardi godina,

100 billion dog years,

100 milijardi psećih godina,

but an infinite number of years into the future.

i bezbroj godina u budućnost.

Meanwhile, for all intents and purposes,

U međuvremenu, nama,

space looks finite to us.

svemir izgleda konačno.

Space may be finite or infinite,

Konačan ili beskonačan,

but because the universe is accelerating,

pošto se ubrzava,

there are parts of it we cannot see

djelove ne možemo vidjeti

and never will see.

i nećemo nikad vidjeti.

There's a finite region of space that we have access to,

Imamo pristup dijelu svemira,

surrounded by a horizon.

zaokruženog horizontom.

So even though time goes on forever,

Dakle iako vrijeme ide zauvijek,

space is limited to us.

svemir nam je ograničen.

Finally, empty space has a temperature.

Na kraju, prazan svemir ima temperaturu.

In the 1970s, Stephen Hawking told us

U 1970-ima, Stephen Hawking je rekao

that a black hole, even though you think it's black,

kako crna rupa

it actually emits radiation

emitira zračenje,

when you take into account quantum mechanics.

kad uzmete u obzir kvantnu mehaniku.

The curvature of space-time around the black hole

Zakrivljenost vrijeme-prostor oko crne rupe

brings to life the quantum mechanical fluctuation,

oživljava kvantnomehaničku fluktuaciju,

and the black hole radiates.

i crna rupa zrači.

A precisely similar calculation by Hawking and Gary Gibbons

Sličan račun Hawkinga i Gary Gibbonsa je pokazao

showed that if you have dark energy in empty space,

da ako imamo tamnu energiju u praznom prostoru,

then the whole universe radiates.

onda cijeli svemir zrači.

The energy of empty space

Energija praznog prostora

brings to life quantum fluctuations.

oživljava kvantne fluktuacije.

And so even though the universe will last forever,

Dakle iako će svemir trajati vječno,

and ordinary matter and radiation will dilute away,

obična materija i zračenje će se razrijediti,

there will always be some radiation,

uvijek će biti nešto zračenja,

some thermal fluctuations,

nešto termičkih fluktuacija,

even in empty space.

čak i u praznom prostoru.

So what this means

To znači

is that the universe is like a box of gas

da je svemir kao kutija plina

that lasts forever.

koja traje zauvijek.

Well what is the implication of that?

Koje su implikacije toga?

That implication was studied by Boltzmann back in the 19th century.

Te implikacije je proučavao Boltzmann još u 19. stoljeću.

He said, well, entropy increases

Rekao je da se entropija povećava

because there are many, many more ways

jer ima puno više načina

for the universe to be high entropy, rather than low entropy.

za svemir da bude više, nego niže entropije.

But that's a probabilistic statement.

To je vjerojatnosna izjava.

It will probably increase,

Vjerojatno će se povećati,

and the probability is enormously huge.

i vjerojatnost je golema.

It's not something you have to worry about --

Ne treba se brinuti da će se

the air in this room all gathering over one part of the room and suffocating us.

zrak u ovoj sobi skupiti na jednu stranu sobe i ugušiti nas.

It's very, very unlikely.

To je vrlo nevjerojatno.

Except if they locked the doors

Osim ako

and kept us here literally forever,

nas drže ovdje zauvijek,

that would happen.

to bi se dogodilo.

Everything that is allowed,

Sve što je moguće,

every configuration that is allowed to be obtained by the molecules in this room,

svaka postava koju je moguće postići molekulama u sobi,

would eventually be obtained.

će se jednom postići.

So Boltzmann says, look, you could start with a universe

Boltzmann kaže, možeš početi sa svemirom

that was in thermal equilibrium.

koji je u termičkoj ravnoteži.

He didn't know about the Big Bang. He didn't know about the expansion of the universe.

On nije znao o Velikom Prasku. Nije znao o širenju svemira.

He thought that space and time were explained by Isaac Newton --

Mislio je da je prostor i vrijeme objasnio Isaac Newton --

they were absolute; they just stuck there forever.

da su apsolutni; zaglavljeni zauvijek.

So his idea of a natural universe

Njegova ideja o prirodnom svemiru

was one in which the air molecules were just spread out evenly everywhere --

kaže da su molekule zraka raspoređene jednoliko --

the everything molecules.

molekule svega.

But if you're Boltzmann, you know that if you wait long enough,

Ali Boltzmann zna da ako dovoljno čekaš,

the random fluctuations of those molecules

slučajne fluktuacije molekula

will occasionally bring them

će ih ponekad dovesti

into lower entropy configurations.

u konfiguraciju niske entropije.

And then, of course, in the natural course of things,

Tada će se, prirodno,

they will expand back.

natrag proširiti.

So it's not that entropy must always increase --

Ne treba se entropija uvijek povećavati --

you can get fluctuations into lower entropy,

ponekad će fluktuirati u nižu entropiju,

more organized situations.

organiziraniju situaciju.

Well if that's true,

Ako je to istina,

Boltzmann then goes onto invent

Boltzmann nadalje nalazi

two very modern-sounding ideas --

dvije moderne ideje --

the multiverse and the anthropic principle.

multisvemir i antropički princip.

He says, the problem with thermal equilibrium

Kaže, problem s termičkom ravnotežom

is that we can't live there.

jest da ne omogućuje život.

Remember, life itself depends on the arrow of time.

Život ovisi o pravcu vremena.

We would not be able to process information,

Ne bi mogli procesirati informacije,

metabolize, walk and talk,

metabolirati, hodati i pričati,

if we lived in thermal equilibrium.

da živimo u termičkoj ravnoteži.

So if you imagine a very, very big universe,

Zamislite velik svemir,

an infinitely big universe,

beskonačno velik

with randomly bumping into each other particles,

sa česticama koje se sudaraju,

there will occasionally be small fluctuations in the lower entropy states,

ponekad će biti malo fluktuacija u stanju niske entropije,

and then they relax back.

i onda se opet smire.

But there will also be large fluctuations.

Ali bit će i velikih fluktuacija.

Occasionally, you will make a planet

Ponekad će nastati planet

or a star or a galaxy

ili zvijezda ili galaksija

or a hundred billion galaxies.

ili sto milijardi galaksija.

So Boltzmann says,

Boltzmann kaže,

we will only live in the part of the multiverse,

živimo u dijelu multisvemira,

in the part of this infinitely big set of fluctuating particles,

u dijelu tog beskonačno velikog seta čestica,

where life is possible.

gdje je život moguć.

That's the region where entropy is low.

To je predio gdje je entropija niska.

Maybe our universe is just one of those things

Možda je naš svemir događaj

that happens from time to time.

koji se desi s vremena na vrijeme.

Now your homework assignment

Za zadaću

is to really think about this, to contemplate what it means.

malo razmislite o tome.

Carl Sagan once famously said

Carl Sagan je rekao

that "in order to make an apple pie,

"kako bi napravili pitu od jabuke,

you must first invent the universe."

prvo morate napraviti svemir."

But he was not right.

Ali nije bio u pravu.

In Boltzmann's scenario, if you want to make an apple pie,

Po Boltzmannu, ako želite napraviti pitu od jabuke,

you just wait for the random motion of atoms

samo čekajte nasumično gibanje atoma

to make you an apple pie.

da složi pitu od jabuke.

That will happen much more frequently

To će se dogoditi češće

than the random motions of atoms

nego da nasumično gibanje atoma

making you an apple orchard

napravi voćnjak od jabuka

and some sugar and an oven,

i šećer i pećnicu,

and then making you an apple pie.

i onda vam napravi pitu od jabuke.

So this scenario makes predictions.

Taj scenarij predviđa

And the predictions are

da su fluktuacije

that the fluctuations that make us are minimal.

koje nas stvaraju minimalne.

Even if you imagine that this room we are in now

Ako zamislite da ova soba postoji

exists and is real and here we are,

i stvarna je, i mi smo tu,

and we have, not only our memories,

i imamo, ne samo sjećanje,

but our impression that outside there's something

nego utisak da vani ima nečega

called Caltech and the United States and the Milky Way Galaxy,

kao Caltech i Sjedinjene države i Mliječni put,

it's much easier for all those impressions to randomly fluctuate into your brain

puno je lakše da ti utisci nasumično fluktuiraju u naš mozak

than for them actually to randomly fluctuate

nego da nasumično fluktuiraju

into Caltech, the United States and the galaxy.

u Caltech, Sjedinjene države i galaksiju.

The good news is that,

Dobra je vijest

therefore, this scenario does not work; it is not right.

da ovaj scenarij ne radi, nije točan.

This scenario predicts that we should be a minimal fluctuation.

On predviđa da smo minimalna fluktuacija.

Even if you left our galaxy out,

I ako dobimo galaksiju,

you would not get a hundred billion other galaxies.

ne bi dobili sto milijardi drugih galaksija.

And Feynman also understood this.

Feynman je to razumio.

Feynman says, "From the hypothesis that the world is a fluctuation,

On kaže, "Od hipoteze da je svijet fluktuacija,

all the predictions are that

svi predviđaju da ako pogledamo

if we look at a part of the world we've never seen before,

dio svijeta koji prije nismo vidjeli,

we will find it mixed up, and not like the piece we've just looked at --

bit će zbrkan i neće biti poput dijela koji smo sada pogledali --

high entropy.

visoka entropija.

If our order were due to a fluctuation,

Da je red tu uslijed fluktuacije,

we would not expect order anywhere but where we have just noticed it.

ne bi očekivali red nigdje drugdje.

We therefore conclude the universe is not a fluctuation."

Tako zaključujemo da svemir nije fluktuacija."

So that's good. The question is then what is the right answer?

To je dobro. Ali koji je onda odgovor?

If the universe is not a fluctuation,

Ako svemir nije fluktuacija,

why did the early universe have a low entropy?

zašto je rani svemir imao nisku entropiju?

And I would love to tell you the answer, but I'm running out of time.

Volio bih vam odgovoriti, ali ponestaje mi vremena.

(Laughter)

(Smijeh)

Here is the universe that we tell you about,

Ovo je svemir o kojem vam govorimo,

versus the universe that really exists.

nasuprot svemira koji jest.

I just showed you this picture.

Pokazao sam ovu sliku.

The universe is expanding for the last 10 billion years or so.

Svemir se širi posljednjih 10 milijardi godina.

It's cooling off.

Hladi se.

But we now know enough about the future of the universe

Ali sad znamo puno više

to say a lot more.

o budućnosti svemira.

If the dark energy remains around,

Ako tamna energija ostane,

the stars around us will use up their nuclear fuel, they will stop burning.

zvijezde oko nas će iskoristiti svoje gorivo, ugasiti će se.

They will fall into black holes.

Past će u crne rupe.

We will live in a universe

Živjet ćemo u svemiru

with nothing in it but black holes.

s ničim osim crnih rupa.

That universe will last 10 to the 100 years --

Takav svemir će trajati 10 do 100 godina --

a lot longer than our little universe has lived.

puno duže nego je dosada živio.

The future is much longer than the past.

Budućnost je puno duža od prošlosti.

But even black holes don't last forever.

Ni crne rupe ne traju zauvijek.

They will evaporate,

Isparit će,

and we will be left with nothing but empty space.

i ostat će nam samo prazan svemir.

That empty space lasts essentially forever.

Taj prazan prostor traje zauvijek.

However, you notice, since empty space gives off radiation,

Ali prazan svemir zrači,

there's actually thermal fluctuations,

ima termičke fluktuacije,

and it cycles around

i vrti se

all the different possible combinations

u svim mogućim kombinacijama

of the degrees of freedom that exist in empty space.

koje su moguće u praznom svemiru.

So even though the universe lasts forever,

Iako svemir traje vječno,

there's only a finite number of things

postoji konačan broj stvari

that can possibly happen in the universe.

koje se mogu dogoditi u njemu.

They all happen over a period of time

Sve se dogode u vremenu

equal to 10 to the 10 to the 120 years.

od 10 na 10 na 120 godina.

So here's two questions for you.

Evo pitanja.

Number one: If the universe lasts for 10 to the 10 to the 120 years,

Prvo: ako svemir toliko traje,

why are we born

zašto se rađamo

in the first 14 billion years of it,

u prvih 14 milijardi godina,

in the warm, comfortable afterglow of the Big Bang?

u toplom rumenilu nakon Velikog Praska?

Why aren't we in empty space?

Zašto nismo u praznom svemiru?

You might say, "Well there's nothing there to be living,"

Reći ćete, "Tamo ništa ne živi,"

but that's not right.

to nije točno.

You could be a random fluctuation out of the nothingness.

Mogli bi biti nasumična fluktuacija iz ničega.

Why aren't you?

Zašto nismo?

More homework assignment for you.

Više zadaće za vas.

So like I said, I don't actually know the answer.

Ja ne znam odgovor.

I'm going to give you my favorite scenario.

Ovo je moj najdraži scenarij.

Either it's just like that. There is no explanation.

Ili je tako, bez objašnjenja.

This is a brute fact about the universe

To je činjenica o svemiru

that you should learn to accept and stop asking questions.

koju trebate naučiti.

Or maybe the Big Bang

Ili Veliki Prasak

is not the beginning of the universe.

nije početak svemira.

An egg, an unbroken egg, is a low entropy configuration,

Nerazbijeno jaje ima malu entropiju,

and yet, when we open our refrigerator,

ali kad otvorimo frižider

we do not go, "Hah, how surprising to find

ne kažemo, "Kako iznenađujuće

this low entropy configuration in our refrigerator."

konfiguracija niske entropije u mom frižideru."

That's because an egg is not a closed system;

To je zato što jaje nije zatvoreni sustav;

it comes out of a chicken.

ono dolazi od kokoši.

Maybe the universe comes out of a universal chicken.

Možda svemir dolazi iz svemirske kokoši.

Maybe there is something that naturally,

Možda nešto prirodno

through the growth of the laws of physics,

kroz rast zakona fizike,

gives rise to universe like ours

rađa svemir kao naš

in low entropy configurations.

u konfiguracijama niske entropije.

If that's true, it would happen more than once;

Ako je to istina, desilo se više puta;

we would be part of a much bigger multiverse.

i mi smo dio većeg multisvemira.

That's my favorite scenario.

To mi je najdraži scenarij.

So the organizers asked me to end with a bold speculation.

Tražili su me da završim s odvažnom špekulacijom.

My bold speculation

Ona je

is that I will be absolutely vindicated by history.

da će me povijest opravdati.

And 50 years from now,

Za 50 godina

all of my current wild ideas will be accepted as truths

sve moje lude ideje će prihvatiti

by the scientific and external communities.

znanstvene zajednice.

We will all believe that our little universe

Svi ćemo vjerovati da je svemir

is just a small part of a much larger multiverse.

dio većeg multisvemira.

And even better, we will understand what happened at the Big Bang

Razumjet ćemo što se desilo kod Velikog Praska

in terms of a theory

teorijom

that we will be able to compare to observations.

koju ćemo moći ispitati.

This is a prediction. I might be wrong.

To je predviđanje.

But we've been thinking as a human race

Kao ljudska rasa smo razmišljali

about what the universe was like,

kakav je svemir,

why it came to be in the way it did for many, many years.

i zašto je ispao ovakav, puno godina.

It's exciting to think we may finally know the answer someday.

Uzbudljivo je misliti da bi mogli naći odgovor.

Thank you.

Hvala.

(Applause)

(Pljesak)