Is time travel possible? - Colin Stuart

Da li je putovanje kroz vreme moguće? - Kolin Stjuart (Colin Stuart)

Prevodilac: Miloš Milosavljević Lektor: Mile Živković

Have you ever daydreamed about traveling through time,

Da li ste ikada maštali

da putujete kroz vreme,

perhaps fast forward in the centuries and seeing the distant future?

možda brzo unapred kroz vekove

i da vidite daleku budućnost?

Well, time travel is possible,

Putovanje kroz vreme je moguće,

and what's more, it's already been done.

štaviše,

već se desilo.

Meet Sergei Krikalev,

Upoznajte Sergeja Krikaleva,

the greatest time traveler in human history.

najvećeg putnika kroz vreme u ljudskoj istoriji.

This Russian cosmonaut holds the record

Ovaj ruski kosmonaut drži rekord

for the most amount of time spent orbiting our planet,

u provedenom vremenu

u orbiti oko naše planete,

a total of 803 days, 9 hours, and 39 minutes.

ukupno 803 dana, 9 sati i 39 minuta.

U toku svog boravka u svemiru

During his stay in space,

he time traveled into his own future

otputovao je u sopstvenu budućnost

by 0.02 seconds.

za 0.02 sekunde.

Traveling at 17,500 miles an hour,

Putujući 28.000 kilometara sat,

he experienced an effect known as time dilation,

iskusio je efekat

poznat kao vremenska dilatacija

and one day the same effect

i jednog dana, ovaj efekat

će možda učiniti značajnije putovanje u budućnost

might make significant time travel to the future commonplace.

uobičajenim.

To see why moving faster through space affects passage of time,

Da bismo videli zašto brže kretanje kroz svemir

utiče na protok vremena,

we need to go back to the 1880s,

moramo da se vratimo u 1880.

when two American scientists,

kada su dva američka naučnika,

Albert Michelson and Edward Morley,

Albert Majklson i Edvard Morli

were trying to measure the effect of the Earth's movement around the Sun

pokušavali da izmere efekat

Zemljinog kretanja oko Sunca

on the speed of light.

na brzinu svetlosti.

When a beam of light was moving in the same direction as the Earth,

Kad se zrak svetlosti kretao

u istom smeru kao Zemlja,

očekivali su da svetlost putuje brže.

they expected the light to travel faster.

And when the Earth was moving in the opposite direction,

A kad se Zemlja kretala u suprotnom smeru,

they expected it to go slower.

očekivali su da putuje sporije.

But they found something very curious.

Ali otkrili su nešto vrlo interesantno.

The speed of light remained the same no matter what the Earth was doing.

Brzina svetlosti je ostala ista

bez obzira kako se Zemlja kretala.

Two decades later, Albert Einstein was thinking

Dve decenije kasnije, Albert Ajnštajn je razmišljao

about the consequences of that never-changing speed of light.

o posledicama

te nepromenljive brzine svetlosti.

And it was his conclusions,

I njegovi zaključci

formulated in the theory of special relativity,

formulisani u Specijalnoj teoriji relativnosti

that opened the door into the world of time travel.

su otvorili vrata

u svet putovanja kroz vreme.

Imagine a man named Jack,

Zamislite čoveka po imenu Džek

standing in the middle of a train carriage,

koji stoji u vagonu voza

traveling at a steady speed.

i putuje konstantnom brzinom.

Džeku je dosadno

Jack's bored and starts bouncing a ball up and down.

i počinje da tapše loptu.

What would Jill, standing on the platform, see through the window

Šta bi Džil, koja stoji na peronu,

videla kroz prozor

dok voz prolazi?

as the train whistles through?

Well, between Jack dropping the ball and catching it again,

Između Džekovog puštanja lopte

i ponovnog hvatanja,

Jill would have seen him move slightly further down the track,

Džil bi ga videla da se pomera

malo dalje duž pruge,

resulting in her seeing the ball follow a triangular path.

što bi za posledicu imalo da vidi loptu

koja pravi trougaonu putanju.

This means Jill sees the ball travel further than Jack does

To znači da Džil vidi duži put lopte

nego Džek

u istom vremenskom periodu.

in the same time period.

And because speed is distance divided by time,

A pošto je brzina jednaka dužini podeljenoj sa vremenom,

Džil u stvari vidi da se lopta kreće brže.

Jill actually sees the ball move faster.

But what if Jack's bouncing ball is replaced with two mirrors

Ali šta ako Džekovu loptu koja skakuće

zamenimo sa dva ogledala

which bounce a beam of light between them?

koja između sebe odbijaju zrak svetlosti?

Jack still sees the beam dropping down

Džek i dalje vidi zrak koji pada ravno nadole,

and Jill still sees the light beam travel a longer distance,

a Džil i dalje vidi zrak

koji prevaljuje duži put,

except this time Jack and Jill cannot disagree on the speed

osim što se, ovaj put, Džek i Džil

slažu u vezi sa brzinom

because the speed of light remains the same no matter what.

jer brzina svetlosti

ostaje ista bez obzira na sve.

And if the speed is the same while the distance is different,

A ako je brzina ista

dok je udaljenost različita,

this means the time taken will be different as well.

to znači da će vreme takođe biti različito.

Thus, time must tick at different rates for people moving relative to each other.

Zbog toga, vreme mora da otkucava različitim tempom

za ljude koji se kreću jedan u odnosu na drugog.

Imagine that Jack and Jill have highly accurate watches

Zamislite da Džek i Džil imaju izuzetno tačne satove

that they synchronize before Jack boards the train.

koje su sinhronizovali pre nego što se Džek ukrcao na voz.

Tokom eksperimenta i Džek i Džil bi videli

During the experiment, Jack and Jill would each see

their own watch ticking normally.

svoje satove koji kucaju normalno.

Ali kad bi se ponovo sreli

But if they meet up again later to compare watches,

da uporede satove,

less time would have elapsed on Jack's watch,

na Džekovom satu bi proteklo manje vremena,

balancing the fact that Jill saw the light move further.

što bi izbalansiralo činjenicu

da je Džil videla svetlost koja putuje duže.

This idea may sound crazy,

Ova ideja možda zvuči ludo,

but like any good scientific theory,

ali, kao svaka dobra naučna teorija,

it can be tested.

može biti proverena.

1970-ih, naučnici su ukrcali u avion

In the 1970s, scientists boarded a plane

with some super-accurate atomic clocks

nekoliko super tačnih atomskih časovnika

that were synchronized with some others left on the ground.

koji su bili sinhronizovani

sa nekoliko drugih koji su ostali na zemlji.

Pošto je avion obleteo Zemlju,

After the plane had flown around the world,

časovnici u avionu su pokazivali različito vreme

the clocks on board showed a different time

od onih koji su ostali na zemlji.

from those left behind.

Of course, at the speed of trains and planes,

Naravno, pri brzinama aviona i vozova

the effect is minuscule.

ovaj efekat je minimalan.

But the faster you go, the more time dilates.

Ali, što brže idete

vreme se više rasteže.

For astronauts orbiting the Earth for 800 days,

Za astronaute koji kruže oko Zemlje 800 dana,

it starts to add up.

ono se nagomilava.

But what affects humans also affects machines.

Ali ono što utiče na ljude, utiče i na mašine.

Satellites of the global positioning system

GPS sateliti

are also hurdling around the Earth

takođe preskaču na putu oko Zemlje

at thousands of miles an hour.

pri brzini od nekoliko hiljada kilometara na sat.

So, time dilation kicks in here, too.

Tako da se vremenska dilatacija javlja i ovde.

In fact, their speed causes the atomic clocks on board

U stvari, njihova brzina prouzrokuje

da se atomski časovnici na njima

to disagree with clocks on the ground

ne slažu sa časovnicima na zemlji

by seven millionths of a second daily.

za 7 milionitih delova sekunde dnevno.

Left uncorrected,

Ako se ovo ne bi ispravljalo,

this would cause GPS to lose accuracy

prouzrokovalo bi da GPS izgubi tačnost

by a few kilometers each day.

za nekoliko kilometara svakog dana.

So, what does all this have to do with time travel

Kakve sve ovo ima veze sa putovanjem kroz vreme

to the far, distant future?

u daleku budućnost?

Well, the faster you go, the greater the effect of time dilation.

Pa, što brže idete,

veći je efekat rastezanja vremena.

If you could travel really close

Kad biste mogli da putujete brzinom

to the speed of light, say 99.9999%,

blizu brzine svetlosti, recimo 99,9999%,

on a round-trip through space

kroz svemir i da se vratite,

for what seemed to you like ten years,

vama bi izgledalo da je prošlo 10 godina,

you'd actually return to Earth

a u stvari biste se vratili na Zemlju

around the year 9000.

oko 9000. godine.

Who knows what you'd see when you returned?!

Ko zna šta biste zatekli kad biste se vratili?!

Humanity merged with machines,

Ljude spojene sa mašinama,

extinct due to climate change or asteroid impact,

istrebljenje prouzrokovano klimatskim promenama

ili udarom asteroida,

or inhabiting a permanent colony on Mars.

ili naseljavanje stalne kolonije na Marsu.

But the trouble is,

Ali problem je to što bi ubrzavanje

težih stvari kao što su ljudi,

getting heavy things like people, not to mention space ships,

a da ne pominjemo svemirske brodove,

up to such speeds requires unimaginable amounts of energy.

do brzine svetlosti

zahtevalo nezamislive količine energije.

It already takes enormous particle accelerators

Već su potrebni ogromni ubrzavači čestica,

like the Large Hadron Collider

kao što je Veliki hadronski sudarač,

to accelerate tiny subatomic particles to close to light speed.

da bi se ubrzale male subatomske čestice

do blizu brzine svetlosti.

But one day, if we can develop the tools to accelerate ourselves to similar speeds,

Ali jednog dana, ako razvijemo alate

da ubrzamo sebe do približnih brzina,

then we may regularly send time travelers

onda bismo mogli da redovno šaljemo putnike kroz vreme

into the future,

u budućnost

bringing with them tales of a long, forgotten past.

i da preko njih prenosimo poruke iz davno zaboravljene prošlosti.