Henry Lin: What we can learn from galaxies far, far away

Prevoditelj: Davorin Jelačić Recezent: Tilen Pigac - EFZG

Here are some images of clusters of galaxies.

Slike prikazuju klastere galaksija.

They're exactly what they sound like.

Onakvi su kako i zvuče.

They are these huge collections of galaxies,

To su velike skupine galaksija,

bound together by their mutual gravity.

međusobno povezanih uzajamnom gravitacijom.

So most of the points that you see on the screen

Većina točkica koje vidite na ekranu

are not individual stars,

nisu pojedinačne zvijezde,

but collections of stars, or galaxies.

već skupovi zvijezda, odnosno galaksije.

Now, by showing you some of these images,

Dok vam pokazujem neke od ovih slika,

I hope that you will quickly see that

nadam se da ćete brzo uvidjeti

galaxy clusters are these beautiful objects,

da su klasteri galaksija prekrasni objekti,

but more than that,

ali i više od toga,

I think galaxy clusters are mysterious,

mislim da su klasteri galaksija tajanstveni,

they are surprising,

iznenađujući,

and they're useful.

i korisni.

Useful as the universe's most massive laboratories.

Korisni kao najmasivnije laboratorije svemira.

And as laboratories, to describe galaxy clusters

Kao i kod laboratorija, objasniti klastere galaksija

is to describe the experiments

znači objasniti eksperimente

that you can do with them.

koje s njima možete provoditi.

And I think there are four major types,

Mislim da postoje 4 glavne vrste,

and the first type that I want to describe

a prva vrsta je

is probing the very big.

ispitivanje vrlo velikog.

So, how big?

Koliko velikog?

Well, here is an image of a particular galaxy cluster.

Ovo je slika određenog klastera galaksija.

It is so massive that the light passing through it

Toliko je masivan da se svjetlost koja kroza nj prolazi

is being bent, it's being distorted

iskrivljava, deformira

by the extreme gravity of this cluster.

uslijed ekstremne gravitacije klastera.

And, in fact, if you look very carefully

Ako pogledate vrlo pažljivo

you'll be able to see rings around this cluster.

moći ćete vidjeti prstenove oko tog klastera.

Now, to give you a number,

Dat ću vam broj,

this particular galaxy cluster

ovaj određeni klaster galaksija

has a mass of over one million billion suns.

ima masu od jednog milijuna milijardi sunaca.

It's just mind-boggling how massive these systems can get.

Nepojmljivo je koliko ti sustavi mogu biti masivni.

But more than their mass,

Ali i više od svoje mase,

they have this additional feature.

oni imaju i dopunsko svojstvo.

They are essentially isolated systems,

Oni su, u suštini, izolirani sustavi,

so if we like, we can think of them

pa ako želimo, možemo na njih gledati

as a scaled-down version of the entire universe.

kao na umanjenu verziju čitavog svemira.

And many of the questions that we might have

I mnoga pitanja koja imamo

about the universe at large scales,

o svemiru na razini vrlo velikoga,

such as, how does gravity work?

na primjer, kako gravitacija djeluje?

might be answered by studying these systems.

možda će dobiti odgovor proučavanjem tih sustava.

So that was very big.

To je što se tiče velikoga.

The second things is very hot.

Druga vrsta predstavlja vrlo vrelo.

Okay, if I take an image of a galaxy cluster,

Ako uzmem sliku klastera galaksija,

and I subtract away all of the starlight,

i eliminiram svu svjetlost zvijezda,

what I'm left with is this big, blue blob.

ostaje mi ova velika, plava mrlja.

This is in false color.

Ovo nije prava boja.

It's actually X-ray light that we're seeing.

Vidimo zapravo svjetlost rendgenskih zraka.

And the question is, if it's not galaxies,

Pitanje je, ako nisu galaksije,

what is emitting this light?

što emitira tu svjetlost?

The answer is hot gas,

Odgovor je vreli plin,

million-degree gas --

plin od milijun stupnjeva --

in fact, it's plasma.

zapravo, plazma.

And the reason why it's so hot

A razlog zašto je tako vrela

goes back to the previous slide.

nalazimo u prethodnom slajdu.

The extreme gravity of these systems

Ekstremna gravitacija ovih sustava

is accelerating particles of gas to great speeds,

ubrzava čestice plina do velikih brzina,

and great speeds means great temperatures.

a velike brzine znače velike temperature.

So this is the main idea,

Ovo je glavna ideja,

but science is a rough draft.

ali znanost je tek grubi nacrt.

There are many basic properties about this plasma

Plazma ima mnogo osnovnih svojstava

that still confuse us,

koje nas još uvijek zbunjuju,

still puzzle us,

još uvijek smućuju,

and still push our understanding

i poguruju naše razumijevanje

of the physics of the very hot.

fizike vrlo vrelog.

Third thing: probing the very small.

Treća vrsta: ispitivanje vrlo malog.

Now, to explain this, I need to tell you

Da bih to objasnio, moram vam reći

a very disturbing fact.

vrlo uznemirujuću činjenicu.

Most of the universe's matter

Većina materije u svemiru

is not made up of atoms.

nije stvorena od atoma.

You were lied to.

Lagali su vam.

Most of it is made up of something very, very mysterious,

Većina je izgrađena od nečega vrlo, vrlo tajanstvenog,

which we call dark matter.

što nazivamo tamnom tvari.

Dark matter is something that doesn't like to interact very much,

Tamna tvar ne voli baš stupati u interakcije,

except through gravity,

osim putem gravitacije,

and of course we would like to learn more about it.

i, naravno, voljeli bismo znati više o njoj.

If you're a particle physicist,

Ako ste fizičar čestica,

you want to know what happens when we smash things together.

želite znati što se događa kada sudaramo stvari.

And dark matter is no exception.

Tamna tvar nije izuzetak.

Well, how do we do this?

Kako to radimo?

To answer that question,

Da bih na to odgovorio,

I'm going to have to ask another one,

moram postaviti još jedno pitanje:

which is, what happens when galaxy clusters collide?

što se događa kad se sudare klasteri galaksija?

Here is an image.

Evo slike.

Since galaxy clusters are representative

Kako su klasteri reprezentativni odsječci svemira,

slices of the universe, scaled-down versions.

umanjene verzije,

They are mostly made up of dark matter,

sastoje se pretežito od tamne tvari,

and that's what you see in this bluish purple.

i to vidite ovdje kao plavičasto-ljubičasto.

The red represents the hot gas,

Crvena predstavlja vreo plin,

and, of course, you can see many galaxies.

i, naravno, možete vidjeti mnoge galaksije.

What's happened is a particle accelerator

Ono što se tu dogodilo je ubrzivač čestica

at a huge, huge scale.

ali ogromnog, ogromnog reda veličine.

And this is very important,

To je vrlo važno,

because what it means is that very, very small

jer znači da se vrlo, vrlo mali učinci,

effects that might be difficult to detect in the lab,

koje bi moglo biti teško otkriti u laboratoriju,

might be compounded and compounded

mogu akumulirati

into something that we could possibly observe in nature.

u nešto što je moguće promatrati u prirodi.

So, it's very funny.

Zanimljivo je to.

The reason why galaxy clusters

Razlog zašto nas klasteri galaksija

can teach us about dark matter,

mogu naučiti nešto o tamnoj tvari,

the reason why galaxy clusters

razlog zašto nas klasteri galaksija

can teach us about the physics of the very small,

mogu naučiti nešto o fizici vrlo malog

is precisely because they are so very big.

je upravo to što su tako veliki.

Fourth thing: the physics of the very strange.

Četvrta vrsta: fizika vrlo čudnog.

Certainly what I've said so far is crazy.

Ovo što sam dosad pričao je svakako vrlo čudno.

Okay, if there's anything stranger

Ako postoji išta čudnije,

I think it has to be dark energy.

to bi morala biti tamna energija.

If I throw a ball into the air,

Ako bacim loptu u zrak,

I expect it to go up.

očekujem da se diže.

What I don't expect is that it go up

Ono što ne očekujem je da se diže

at an ever-increasing rate.

i pritom sve više ubrzava.

Similarly, cosmologists understand why

Slično, kozmolozi razumiju

the universe is expanding.

zašto se svemir širi.

They don't understand why it's expanding

Ne razumiju zašto se širi

at an ever-increasing rate.

sve većom i većom brzinom.

They give the cause of this

Uzrok te ubrzavajuće ekspanzije

accelerated expansion a name,

ima ime,

and they call it dark energy.

zovu to tamna energija.

And, again, we want to learn more about it.

Opet, želimo naučiti više o njoj.

So, one particular question that we have is,

Jedno konkretno pitanje koje imamo je,

how does dark energy affect the universe

kako tamna energija utječe na svemir

at the largest scales?

najvećeg reda veličine?

Depending on how strong it is,

Ovisno o tome koliko je snažna,

maybe structure forms faster or slower.

možda strukture nastaju brže ili sporije.

Well, the problem with the large-scale structure

Problem s vrlo velikim strukturama svemira

of the universe is that it's horribly complicated.

je u njihovoj užasnoj kompliciranosti.

Here is a computer simulation.

Evo računalne simulacije.

And we need a way to simplify it.

Treba nam način da to pojednostavimo.

Well, I like to think about this using an analogy.

Volim o tome razmišljati pomoću analogije.

If I want to understand the sinking of the Titanic,

Ako želim razumjeti potonuće Titanica,

the most important thing to do

nije najvažnije modelirati

is not to model the little positions

sitne pozicije

of every single little piece of the boat that broke off.

baš svakog brodskog komadića koji se odlomio.

The most important thing to do is

Najvažnija stvar je

to track the two biggest parts.

pratiti dva najveća dijela.

Similarly, I can learn a lot about the universe

Slično, mogu naučiti puno o svemiru

at the largest scales

na razini vrlo velikog

by tracking its biggest pieces

prateći najveće objekte,

and those biggest pieces are clusters of galaxies.

a ti najveći komadi su klasteri galaksija.

So, as I come to a close,

Kako se približavam kraju govora,

you might feel slightly cheated.

možda se osjećate pomalo prevareni.

I mean, I began by talking about

Mislim, počeo sam priču o tome

how galaxy clusters are useful,

kako su klasteri galaksija korisni,

and I've given some reasons,

i naveo čak i neke razloge,

but what is their use really?

ali koja je stvarna korist od njih?

Well, to answer this,

Da bih vam odgovorio,

I want to give you a quote by Henry Ford

dat ću vam navod Henryja Forda

when he was asked about cars.

kad su ga pitali o automobilima.

He had this to say:

Rekao je ovo:

"If I had asked people what they wanted,

"Da sam pitao ljude što žele,

they would have said faster horses."

rekli bi da žele brže konje."

Today, we as a society are faced

Danas, naše se društvo suočava

with many, many difficult problems.

s brojnim teškim problemima.

And the solutions to these problems are not obvious.

Rješenja tih problema nisu očigledna.

They are not faster horses.

Rješenja nisu brži konji.

They will require an enormous amount of

Zahtijevat će ogromnu količinu

scientific ingenuity.

znanstvene kreativnosti.

So, yes, we need to focus,

Dakle, moramo se usredotočiti,

yes, we need to concentrate,

da, moramo se koncentrirati,

but we also need to remember that

ali također i upamtiti

innovation, ingenuity, inspiration --

da inovacije, kreativnost, inspiracija --

these things come

one dolaze

when we broaden our field of vision

kada proširimo naš vidokrug,

when we step back

kada učinimo korak unatrag,

when we zoom out.

kada se udaljimo.

And I can't think of a better way to do this than

A ja ne mogu smisliti bolji način da to postignemo

by studying the universe around us. Thanks.

od proučavanja svemira oko nas. Hvala.

(Applause)

(Pljesak)