How to detect a supernova - Samantha Kuula

Kako otkriti supernovu - Samanta Kula (Samantha Kuula)

Prevodilac: Tijana Mihajlović Lektor: Ivana Krivokuća

Just now, somewhere in the universe, a star exploded.

Upravo sada, negde u svemiru, eksplodirala je zvezda.

There goes another one.

Evo još jedne.

In fact, a supernova occurs every second or so in the observable universe,

U stvari, supernova se javlja svake sekunde

ili približno u uočljivom svemiru,

and there is one on average every 25 to 50 years

dok se jedna u proseku javlja u periodu od 25 do 50 godina

in a galaxy the size and age of the Milky Way.

u galaksiji veličine i starosti Mlečnog puta.

Yet we've never actually been able to watch one happen

Ipak, nikada nismo mogli da posmatramo neku dok se dešava

from its first violent moments.

počevši od prvih silovitih trenutaka.

Of course, how would we?

Naravno, i kako bismo mogli?

Postoji stotine milijardi zvezda koje su dovoljno blizu

There are hundreds of billions of stars close enough

that we could watch the supernova explosion

da bismo mogli da posmatramo eksploziju supernove

break through the surface of the star.

kako izbija na površinu zvezde.

But we'd have to have our best telescopes focused on the right one

Međutim, morali bismo da fokusiramo najbolje teleskope na pravu zvezdu

at precisely the right time to get meaningful data.

u baš to vreme da bismo dobili smislene podatke.

Dovoljno je reći da su šanse da se to desi astronomski male.

Suffice it to say, the odds of that happening are astronomically low.

But what if we could anticipate a supernova before its light reached us?

Šta ako bismo, međutim, mogli predvideti supernovu

pre nego što njeno svetlo stigne do nas?

That may seem impossible.

To može delovati nemoguće.

After all, nothing travels faster than the speed of light, right?

Na kraju krajeva, ništa ne putuje brže od brzine svetlosti, zar ne?

As far as we know, yes.

Prema onome što znamo - da,

But in a race, fast doesn't matter if you take a detour

ali u trci, brzina nije važna ako skrenete sa puta

while someone else beelines it for the finish line.

dok neko drugi ide pravo do cilja.

For exactly that reason,

Iz istih razloga,

photons don't win the supernova race to Earth.

fotoni ne pobeđuju u supernova trci do Zemlje.

Neutrinos do.

Neutrini pobeđuju.

Here's why.

Evo i zašto.

There are two types of supernova.

Postoje dve vrste supernove.

Type 1 is when a star accumulates so much matter from a neighboring star,

Prva vrsta je kada zvezda nakupi toliko materije sa susedne zvezde

that a runaway nuclear reaction ignites and causes it to explode.

da se preuzeta nuklearna energija pali i uzrokuje da eksplodira.

In type 2, the star runs out of nuclear fuel,

Kod druge vrste, zvezdi nestane nuklearnog goriva,

so the gravitational forces pulling in

pa gravitacione sile koje vuku unutra

overwhelm the quantum mechanical forces pushing out,

preplavljuju sile kvantne mehanike koje vuku prema van,

and the stellar core collapses under its own weight in a hundredth of a second.

a jezgro zvezde se urušava pod sopstvenom težinom

u stotom delu sekunde.

While the outer reaches of the star are unaffected by the collapsed core,

Dok spoljašnji delovi zvezde nisu pogođeni urušenim jezgrom,

the inner edges accelerate through the void,

unutrašnji delovi ubrzavaju kroz prazninu,

smash into the core, and rebound to launch the explosion.

udaraju u jezgro i odbijaju se kako bi započeli eksploziju.

In both of these scenarios,

U oba ova scenarija,

the star expels an unparalleled amount of energy,

zvezda izbacuje ogromnu energiju,

as well as a great deal of matter.

kao i ogromnu količinu materije.

In fact, all atoms heavier than nickel, including elements like gold and silver,

U stvari, svi atomi teži od nikla, uključujući i elemente

kao što su zlato i srebro,

only form in supernova reactions.

formiraju se samo pri hemijskim reakcijama supernove.

In type 2 supernovae,

U drugoj vrsti supernove,

about 1% of the energy consists of photons,

oko 1% energije sastoji se od fotona,

which we know of as light,

koje prepoznajemo kao svetlo,

while 99% radiates out as neutrinos,

dok se 99% isijava kao neutrini,

the elementary particles that are known for rarely interacting with anything.

elementarne čestice koje su poznate po tome

da veoma retko ulaze u interakciju sa bilo čime.

Starting from the center of the star,

Počevši od centra zvezde,

the exploding matter takes tens of minutes, or even hours,

materiji koja je eksplodirala treba deset minuta, ili čak sati,

or in rare cases, several days, to reach and break through the surface of the star.

ili, u retkim slučajevima, nekoliko dana

da stigne i probije se kroz površinu zvezde.

However, the neutrinos, thanks to their non-interactivity,

Neutrini, međutim, zahvaljujući nepostojanju interakcije,

take a much more direct route.

imaju mnogo direktniji pravac.

By the time there is any visible change in the star's suface,

Do trenutka vidljive promene na površini zvezde,

the neutrinos typically have a several hour head start over the photons.

neutrini obično imaju nekoliko sati prednosti nad fotonima.

That's why astronomers and physicists

Zbog toga su astronomi i fizičari

have been able to set up a project called SNEWS,

uspeli da pokrenu projekat pod imenom „SNEWS" –

the Supernova Early Warning System.

„Rani sistem upozorenja o supernovi".

When detectors around the world pick up bursts of neutrinos,

Kada detektori širom sveta pokupe signale eksplozije neutrina,

they send messages to a central computer in New York.

šalju poruke centralnom kompjuteru u Njujorku.

If multiple detectors receive similar signals within ten seconds,

Ako više detektora primi slične signale tokom deset sekundi,

SNEWS will trigger an alert warning that a supernova is imminent.

„SNEWS" će pokrenuti znak za uzbunu da se supernova bliži.

Aided by some distance and direction information from the neutrino detectors,

Uz pomoć udaljenosti i informacija o pravcu iz detektora neutrina,

the amateur astronomers and scientists alike

amaterski astronomi i slični naučnici

will scan the skies and share information

skeniraće nebo i razmeniti informacije

to quickly identify the new galactic supernova

da bi brzo identifikovali novu galaktičku supernovu

and turn the world's major telescopes in that direction.

i okrenuli glavne svetske teleskope u tom pravcu.

The last supernova that sent detectable neutrinos to Earth was in 1987

Poslednja supernova koja je poslala primetne neutrine na Zemlju

bila je 1987. godine, na rubu magline Tarantula

on the edge of the Tarantula Nebula

in the large Magellanic Cloud, a nearby galaxy.

u velikom Magelanovom oblaku, obližnjoj galaksiji.

Its neutrinos reached Earth about three hours ahead of the visible light.

Njeni neutrini su stigli do Zemlje otprilike tri sata pre vidljivog svetla.

We're due for another one any day now, and when that happens,

Svakoga dana očekujemo još jednu, a kada se to desi,

SNEWS should give you the opportunity to be among the first to witness something

„SNEWS" bi trebalo da vam da priliku da budete među prvima

koji će prisustvovati nečemu što nijedno ljudsko biće nikada nije videlo.

that no human has ever seen before.