How do we study the stars? - Yuan-Sen Ting

Kako proučavamo zvezde? - Juan-Sen Ting (Yuan-Sen Ting)

Prevodilac: Tijana Mihajlović Lektor: Mile Živković

The city sky is, frankly, rather boring.

Gradsko nebo je, iskreno, prilično dosadno.

If you look up at the patches of murk between buildings,

Ako pogledate naviše u mračne delove između zgrada,

you might be able to pick out The Big Dipper,

možda ćete moći da uočite Velikog medveda

or perhaps, Orion's Belt.

ili Orionov pojas,

But hold on.

ali sačekajte.

Look at that murky patch again and hold our your thumb.

Pogledajte u taj tamni deo opet i ispružite palac.

How many stars do you think are behind it?

Šta mislite, koliko ima zvezda iza njega?

Ten, twenty? Guess again.

Deset, dvadeset? Pogađajte ponovo.

If you looked at that thumbnail-sized patch of sky

Ako pogledate u taj deo neba veličine nokta na palcu

with the Hubble Space Telescope,

kroz svemirski teleskop Habl,

instead of points of light, you'd see smudges.

umesto tačkica svetlosti, videćete mrlje.

These aren't stars.

Ovo nisu zvezde.

They're galaxies, just like our Milky Way.

To su galaksije kao što je naš Mlečni put.

Cities of billions of stars,

Gradovi od milijardu zvezda,

and more than 1,000 of them are hidden behind your thumb.

a više od hiljadu skriva se iza vašeg palca.

The universe is bigger than you can see from the city,

Svemir je veći nego što možete videti iz grada

and even bigger than the starry sky you can see from the countryside.

i mnogo je veći nego zvezdano nebo koje možete videti kada ste na selu.

This is the universe as astrophysicists see it,

Ovo je svemir kako ga vide astrofizičari,

with more stars than all the grains of sand on Earth.

sa mnogo više zvezda nego što ima zrna peska na Zemlji.

By staring up at the stars at night,

Dok zurite u zvezde noću,

you've taken part in the oldest science in human history.

učestvujete u najstarijoj nauci u ljudskoj istoriji.

The study of the heavens is older than

Proučavanje neba je starije

navigation, agriculture, perhaps even language itself.

od navigacije, poljoprivrede, možda čak i samog jezika.

Yet unlike other sciences, astronomy is purely observational.

Ipak, suprotno drugim naukama, astronomija je potpuno posmatračka.

We cannot control the parameters of our experiments from lab benches.

Ne možemo kontrolisati parametre naših eksperimenata

iz laboratorijskih klupa.

Our best technology can send man to the moon,

Naša najbolja tehnologija može poslati čoveka na Mesec

and probes to the edge of the solar system.

i istražuje do granica našeg Sunčevog sistema,

But these distances are vanishingly small

ali ove udaljenosti su relativno male

compared to the yawning gulfs between stars.

ako se uporede sa razjapljenim jazovima između zvezda.

So how can we know so much about other galaxies,

Kako onda znamo toliko mnogo o drugim galaksijama -

what they're made of, how many there are, or that they're even there at all?

od čega su sačinjene, koliko ih ima, ili da su uopšte tamo?

Well, we can start with the first thing we see when we look up at night: the stars.

Pa, možemo početi od prve stvari koju vidimo

kada gledamo naviše po noći - od zvezda.

What we are trying to learn is their properties.

Ono što pokušavamo da shvatimo su njihova svojstva.

What are they made of? How hot are they? How massive? How old?

Od čega su? Koliko su vrele? Koliko masivne? Koliko stare?

How far are they from Earth?

Koliko su udaljene od Zemlje?

And believe it or not,

Verovali ili ne,

we can learn all of these things simply from the light shining in the sky.

možemo da naučimo ove stvari kroz jednostavno sijanje svetla na nebu.

We can decipher one kind of stellar message by turning starlight into rainbows.

Možemo odgonetnuti jednu vrstu zvezdane poruke

kroz pretvaranje svetlosti zvezda u duge.

When you look at a rainbow on Earth,

Kada pogledate u dugu na Zemlji,

you're really looking at light from our Sun

zapravo gledate u svetlo sa Sunca

being scattered through water droplets in the atmosphere

koje je rasuto kroz vodene kapi iz atmosfere

into all the different wavelengths that make it up.

u sve te različite talasne dužine koje je čine.

And we study the light from other stars,

Proučavamo svetlo sa drugih zvezda

we can create rainbows on demand using not water droplets,

tako što stvaramo duge prema potrebi koristeći ne vodene kapi,

but other specific instruments that disperse light.

već druge specifične instrumente koji raspršuju svetlost.

When we look at the scattered light from our sun,

Kada pogledamo raspršenu svetlost sa našeg Sunca,

we see something strange: dark lines in our rainbow.

vidimo nešto čudno - crne linije u dugi.

These lines are the characteristic fingerprints of atoms.

Ove linije su karakteristični otisci prstiju atoma.

Each type of atom in the solar atmosphere soaks up light at specific wavelengths,

Svaki tip atoma u Sunčevoj atmosferi upija svetlost

na specifičnim talasnim dužinama,

and the amount of absorption depends on how many of these atoms there are.

a količina apsorpcije zavisi od toga koliko ima atoma.

So by observing how much light is missing at these characteristic wavelengths,

Kroz posmatranje koliko svetlosti fali

na ovim karakterističnim talasnim dužinama,

we can tell not only what elements are in the Sun's atmosphere,

možemo znati koji se elementi nalaze u Sunčevoj atmosferi,

but even their concentrations.

ali čak i njihovu koncentraciju.

And the same idea can be applied to study other stars.

Ista ideja može se primeniti na proučavanje zvezda.

Make a spectral rainbow, see what's missing,

Napravite spektralnu dugu, vidite šta nedostaje

and figure out which elements are present.

i shvatite koji su elementi prisutni.

Bingo. Now you know what stars are made of.

Bingo! Sada znate od čega se zvezde sastoje.

But we aren't restricted to just the wavelengths that our eyes perceive.

Nismo, međutim, ograničeni samo na talasne dužine koje naše oko uočava.

Consider radio waves.

Uzmite u obzir talasne dužine radija.

Yes, they can bring the Billboard Top 100 to your car,

Da, mogu doneti „Bilbord top 100" u vaša kola,

but they can also travel almost unimpeded through space.

ali mogu i da skoro neometano putuju kroz svemir.

Because they've come so far,

Zato što su došli do ovolike udaljenosti,

radio waves can tell us the very early history of the universe,

mogu nam reći veoma ranu istoriju svemira,

from just a few thousand years after The Big Bang.

od pre samo nekoliko hiljada godina posle Velikog praska.

We can also study the infrared light, emitted by colder objects,

Možemo proučavati i infracrveno svetlo koje emituju hladniji objekti,

like the gas and dust clouds in space,

kao što su oblaci od gasa i prašine u svemiru

and the ultraviolet light from the hot stars recently born from those clouds.

i ultraljubičasto svetlo sa vrelih zvezda koje su se nedavno rodile iz ovih oblaka.

Studying different wavelengths not only gives us

Proučavanje različitih talasnih dužina

a more complete picture of any single object

ne samo da nam daje

kompletniju sliku o bilo kom pojedinačnom objektu,

but also different views of the universe.

već i različite poglede na svemir.

For this reason, astrophysicists use several different kinds of telescopes

Zbog ovoga, astrofizičari koriste nekoliko različitih vrsta teleskopa

covering the spectrum from the infrared to the ultraviolet to the X-ray,

pokrivajući spektar od infracrvenih preko ultraljubičastih do x-zraka,

from giant radio dishes to giant silver mirrors to space satellites,

od ogromnih radio antena preko ogromnih srebrnih ogledala do svemirskih satelita,

detecting light that would be otherwise blocked by the Earth's atmosphere.

detektujući svetlo koje bi u suprotnom blokirala Zemljina atmosfera.

Astrophysicists don't just see

Astrofizičari ne vide samo

the billions of stars among the billions of galaxies in the universe.

milijarde zvezda među milijardama galaksija u svemiru.

They hear, feel and sense them through many channels,

Oni ih čuju, osećaju i naslućuju kroz mnogobrojne kanale,

each revealing a different story.

od kojih svaki otkriva različitu priču.

But it all begins with light, the kind we can see and the kind we can't.

Sve, međutim, počinje sa svetlošću, onom koju vidimo i ne vidimo.

Want to know the secrets of the Universe?

Želite da znate tajne svemira?

Just follow the light.

Samo pratite svetlo.