Dark matter: How does it explain a star's speed? - Don Lincoln

Kako se tamnom materijom objašnjava brzina zvezde? - Don Linkoln (Don Lincoln)

Transcriber: tom carter Reviewer: Bedirhan Cinar

Prevodilac: Tijana Mihajlović Lektor: Mile Živković

Of all the spectacles mankind has viewed through a telescope,

Od svih prizora koje je čovečanstvo videlo kroz teleskop,

there are few lovelier than a spiral galaxy.

malo njih je lepše od spiralne galaksije.

Majestic whirlpools of stars, they rotate in a stately and predictable dance.

Veličanstveni vrtlozi zvezda koji se kreću u svečanom, predvidivom plesu.

The fact that we see many billions of them in our telescopes

Činjenica da ih u našim teleskopima vidimo toliko milijardi

tells us they are both common and stable.

govori nam da su one česte i stabilne.

It is perhaps surprising that it is relatively easy to understand the inner workings of these cosmic pinwheels.

Možda iznenađuje to da je relativno lako

razumeti funkcionisanje ovih kosmičkih vetrenjača.

By combining physical principles worked out by Sir Isaac Newton in the late 17th century,

Kombinovanjem fizičkih principa koje je u 17. veku razradio Isak Njutn,

with the observed amount of mass in a galaxy,

sa posmatranom količinom mase u galaksiji,

scientists can calculate the rates at which these galaxies rotate.

naučnici mogu da izračunaju brzine po kojima se ove galaksije rotiraju.

Using these techniques, astronomers predict how fast stars at different distances from the center of the galaxy should move.

Uz ove tehnike, astronomi predviđaju koliko brzo treba da se pomeraju zvezde

na različitim udaljenostima od centra galaksije.

Stars very close to the center move slowly.

Zvezde blizu centra kreću se sporo.

That's because there is very little mass between them and the center of the galaxy to pull them along.

To je zbog toga što između njih i centra galaksije

ima veoma malo mase da ih razdvoji.

Stars a bit further away move faster,

Udaljenije zvezde kreću se brže

because they are being pulled by all of the stars in between them and the center.

zato što ih vuku sve zvezde između njih i centra.

As we get really far away, the stars are predicted to move slowly again.

Kako se više udaljavamo, predviđa se da će se zvezde opet kretati polako.

Their great distance reduces gravity to a gentle tug,

Njihova velika udaljenost gravitaciju smanjuje na blago guranje,

so they move leisurely in their orbits.

tako da se lagano kreću u svojim orbitama.

Knowing this, scientists looked at the galaxies and measured how fast stars were moving.

Znajući ovo, naučnici su posmatrali galaksije i merili brzinu kretanja zvezda.

Iznenadilo ih je što su otkrili da, iako se zvezde bliže centru

To their surprise, they found that while the stars closer to the center of the galaxy behaved as predicted,

ponašaju prema proračunima,

those further away moved far too quickly.

one dalje su se pomerale prebrzo.

Ovo zapažanje bilo je poražavajuće

This observation was devastating to the tradtional theories of gravity and motion.

po tradicionalne teorije gravitacije i pokreta.

If the stars were moving as fast as their measurement suggested,

Ako su se zvezde pomerale brzinom koju je merenje predvidelo,

galaxies should have torn themselves apart.

galaksije bi same sebe razorile.

It was a crisis, and astronomers and physicists scrambled to find a mistake in their calculation.

Bila je to kriza, a astronomi i fizičari razleteli su se

da nađu grešku u svojim proračunima.

Was Newton's theory of gravity wrong?

Da li je Njutnova teorija gravitacije pogrešna?

Was his theory of motion wrong?

Da li je teorija kretanja pogrešna?

Or was it possible that astronomers had incorrectly measured the galaxy's mass?

Da li je moguće da su astronomi pogrešno izračunali masu galaksije?

All options were investigated, and all were ruled out. Except one.

Sve opcije su istražene i sve su odbačene; sve osim jedne.

Today, scientists believe that the answer lies in a previously unknown kind of matter, called dark matter.

Danas, naučnici veruju da odgovor leži u prethodno nepoznatoj vrsti materije,

nazvanoj tamna materija.

This dark matter can be envisioned as a cloud which surrounds most galaxies.

Ova tamna materija se može zamisliti kao oblak koji okružuje većinu galaksija.

This matter is very unusual. It is affected by gravity,

Veoma je neobična. Na nju utiče gravitacija,

but it is invisible to visible light and all other forms of electromagnetic radiation.

ali je nevidljiva vidljivom svetlu

i svim drugim oblicima elektromagnetnog zračenja.

The name "dark matter" originates in this form of matter's inability to emit or absorb light.

Naziv „tamna materija” potiče iz nemogućnosti ove materije

da emituje ili apsorbuje svetlost.

Dark matter adds to the gravity of the galaxy

Tamna materija doprinosi gravitaciji galaksije

and explains the orbital speed of stars far from the galactic center.

i objašnjava brzinu kruženja zvezda udaljenih od galaktičkog središta.

Dark matter has not yet been directly observed,

Tamna materija još uvek nije direktno uočena,

but scientists believe that it is likely to be real,

ali naučnici veruju da je verovatno da postoji,

mostly because the other options have been ruled out.

mahom zbog toga što su druge opcije isključene.

Using dozens of approaches, astronomers and physicists continue to search for direct evidence

Koristeći desetak principa, astronomi i fizičari

nastavljaju da traže direktne dokaze

that would prove that the dark matter hypothesis is true.

koji bi potvrdili da je hipoteza o tamnoj materiji tačna.

This question is one of the most important physics research questions of the 21st century.

Ovo pitanje je jedno od najvažnijih istraživačkih pitanja fizike u 21. veku.