Where did the Moon come from? A new theory | Sarah T. Stewart

Prevoditelj: Ines Rad Recezent: Sanda L

Nobody likes to make a mistake.

Nitko ne voli činiti pogreške.

And I made a whopping one.

A ja sam napravila ogromnu.

And figuring out what I did wrong led to a discovery

Moja je pogreška dovela do otkrića

that completely changes the way we think about the Earth and Moon.

koje u potpunosti mijenja način na koji razmišljamo o Zemlji i Mjesecu.

I'm a planetary scientist,

Planetarna sam znanstvenica

and my favorite thing to do is smash planets together.

i više od svega volim sudarati planete.

(Laughter)

(Smijeh)

In my lab, I can shoot at rocks using cannons like this one.

U laboratoriju mogu pucati u stijene iz topova kao što je ovaj.

(Cannon shot)

(Pucanj topa)

(Laughter)

(Smijeh)

In my experiments, I can generate the extreme conditions

Eksperimentima mogu stvoriti ekstremne uvjete

during planet formation.

za vrijeme formacije planeta.

And with computer models, I can collide whole planets together

A zahvaljujući računalnim modelima, mogu međusobno sudarati čitave planete

to make them grow,

da narastu

or I can destroy them.

ili da ih uništim.

(Laughter)

(Smijeh)

I want to understand how to make the Earth and the Moon

Želim shvatiti kako stvoriti Zemlju i Mjesec

and why the Earth is so different from other planets.

i zašto se Zemlja toliko razlikuje od drugih planeta.

The leading idea for the origin of the Earth and Moon

Prevladavajuća teorija o nastanku Zemlje i Mjeseca

is called the "giant impact theory."

naziva se "teorija velikog udara".

The theory states that a Mars-sized body struck the young Earth,

Teorija tvrdi da je tijelo veličine Marsa udarilo u mladu Zemlju,

and the Moon formed from the debris disk around the planet.

a Mjesec je nastao iz prstena krhotina koji je okružio planet.

The theory can explain so many things about the Moon,

Ova teorija može objasniti toliko toga o Mjesecu

but it has a huge flaw:

ali ima jedan veliki nedostatak:

it predicts that the Moon is mostly made from the Mars-sized planet,

po njoj je Mjesec većim dijelom nastao od planeta veličine Marsa,

that the Earth and the Moon are made from different materials.

po njoj su Zemlja i Mjesec građeni od različitih materijala.

But that's not what we see.

Ali dokazi pokazuju suprotno.

The Earth and the Moon are actually like identical twins.

Zemlja i Mjesec zapravo su poput identičnih blizanaca.

The genetic code of planets is written in the isotopes of the elements.

Genetski kôd planeta zapisan je u izotopima elemenata.

The Earth and Moon have identical isotopes.

Zemlja i Mjesec imaju identične izotope.

That means that the Earth and Moon are made from the same materials.

Dakle, Zemlja i Mjesec građeni su od istih materijala.

It's really strange that the Earth and the Moon are twins.

Prilično je čudno da su Zemlja i Mjesec blizanci.

All of the planets are made from different materials,

Svi su planeti građeni od različitih materijala,

so they all have different isotopes,

stoga imaju različite izotope,

they all have their own genetic code.

svaki ima svoj vlastiti genetski kôd.

No other planetary bodies have the same genetic relationship.

Niti jedno drugo nebesko tijelo nema ovakvu genetsku poveznicu.

Only the Earth and Moon are twins.

Samo su Zemlja i Mjesec blizanci.

When I started working on the origin of the Moon,

Kad sam počela raditi na postanku Mjeseca,

there were scientists that wanted to reject the whole idea of the giant impact.

bilo je znanstvenika koji su htjeli potpuno odbaciti ideju o velikom udaru.

They didn't see any way for this theory to explain the special relationship

Nisu vidjeli kako ovom teorijom objasniti

posebnu vezu Zemlje i Mjeseca.

between the Earth and the Moon.

We were all trying to think of new ideas.

Svi smo pokušavali smisliti nova rješenja.

The problem was, there weren't any better ideas.

Problem je bio što nije bilo boljih rješenja.

All of the other ideas had even bigger flaws.

Sva su druga rješenja imala još veće nedostatke.

So we were trying to rescue the giant impact theory.

Stoga smo pokušali spasiti teoriju velikog udara.

A young scientist in my group suggested that we try changing the spin

Mladi znanstvenik u mojoj grupi predložio je da pokušamo promijeniti

rotaciju velikog udara.

of the giant impact.

Maybe making the Earth spin faster could mix more material

Kad bi se Zemlja vrtjela brže, možda bi se pomiješalo više materijala

and explain the Moon.

i objasnilo Mjesec.

The Mars-sized impactor had been chosen

Tijelo veličine Marsa odabrano je

because it could make the Moon

jer objašnjava i Mjesec

and make the length of Earth's day.

i duljinu Zemljinog dana.

People really liked that part of the model.

Ljudima se doista sviđao taj dio modela.

But what if something else determined the length of Earth's day?

Ali što kada bi nešto drugo određivalo duljinu Zemljinog dana?

Then there would be many more possible giant impacts that could make the Moon.

Otvorila bi se mogućnost drugačijih velikih udara kojima bi nastao Mjesec.

I was curious about what could happen,

Zanimalo me što bi se dogodilo

so I tried simulating faster-spinning giant impacts,

pa sam pokušala simulirati velike udare brže rotacije

and I found that it is possible

i otkrila da je moguće da prsten nastane

to make a disk out of the same mixture of materials as the planet.

od iste mješavine materijala kao i planet.

We were pretty excited.

Bili smo prilično uzbuđeni.

Maybe this was the way to explain the Moon.

Možda je to način da objasnimo Mjesec.

The problem is, we also found that that's just not very likely.

No također smo otkrili i da je vjerojatnost za to vrlo mala.

Most of the time, the disk is different from the planet,

Prsten se u većini slučajeva razlikuje od planeta

and it looked like making our Moon this way

i činilo se da bi pokušaj da na ovaj način izgradimo Mjesec

would be an astronomical coincidence,

bio tek astronomska slučajnost,

and it was just hard for everyone to accept the idea

a svima je bilo teško prihvatiti ideju

that the Moon's special connection to Earth was an accident.

da je Mjesečeva posebna povezanost sa Zemljom samo slučajnost.

The giant impact theory was still in trouble,

Teorija velikog udara i dalje je bila u problemima,

and we were still trying to figure out how to make the Moon.

a mi smo i dalje pokušavali otkriti kako napraviti Mjesec.

Then came the day when I realized my mistake.

Zatim je došao dan kada sam shvatila gdje sam pogriješila.

My student and I were looking at the data from these fast-spinning giant impacts.

Moj učenik i ja pregledavali smo podatke tih velikih udara brze rotacije.

On that day, we weren't actually thinking about the Moon,

Toga dana nismo razmišljali o Mjesecu,

gledali smo planet.

we were looking at the planet.

The planet gets super-hot and partially vaporized

Planet se ekstremno zagrije i dijelom pretvori u plin

from the energy of the impact.

od energije udara.

But the data didn't look like a planet.

Ali podaci nisu davali sliku planeta.

It looked really strange.

Izgledalo je čudno.

The planet was weirdly connected to the disk.

Planet i prsten bili su spojeni na čudan način.

I got that super-excited feeling

Obuzeo me onaj intenzivan osjećaj uzbuđenja,

when something really wrong might be something really interesting.

kad znate da bi nešto potpuno krivo moglo biti nešto jako zanimljivo.

In all of my calculations,

U svim sam izračunima

I had assumed there was a planet with a separate disk around it.

pretpostavila postojanje planeta s odvojenim prstenom koji ga okružuje.

Calculating what was in the disk as how we tested

Izračunima sastava prstena testirali smo mogućnost

whether an impact could make the Moon.

da udarcem nastane Mjesec.

But it didn't look that simple anymore.

Ali više nije bilo tako jednostavno.

We were making the mistake

Naša je pogreška bila

of thinking that a planet was always going to look like a planet.

što smo mislili da će planet uvijek izgledati kao planet.

On that day, I knew that a giant impact was making something completely new.

Toga dana, znala sam da je velikim udarom nastalo nešto potpuno novo.

I've had eureka moments.

Doživjela sam prije aha trenutke.

This was not one of them.

Ovo nije bio jedan od njih.

(Laughter)

(Smijeh)

I really didn't know what was going on.

Doista nisam shvaćala što se događa.

I had this strange, new object in front of me

Gledala sam u to čudno novo tijelo

and the challenge to try and figure it out.

i pokušavala ga shvatiti.

What do you do when faced with the unknown?

Što učiniti kad ste suočeni s nepoznatim?

How do you even start?

Odakle uopće početi?

We questioned everything:

Preispitivali smo sve:

What is a planet?

Što je planet?

When is a planet no longer a planet anymore?

U kojem trenutku planet više nije planet?

We played with new ideas.

Igrali smo se novim idejama.

We had to get rid of our old way of thinking,

Morali smo odbaciti stari način razmišljanja,

and by playing, I could throw away all of the data,

a igrajući se, mogla sam odbaciti sve podatke,

all of the rules of the real world,

sva pravila stvarnog svijeta

and free my mind to explore.

i osloboditi um da istražuje.

And by making a mental space

Izgradivši mentalni prostor

where I could try out outrageous ideas

u kojem sam mogla ispitivati nevjerojatne ideje

and then bring them back into the real world to test them,

pa ih prenijeti u stvarni svijet i testirati ih,

I could learn.

mogla sam učiti.

And by playing, we learned so much.

Igrajući se, toliko smo toga naučili.

I combined my lab experiments with computer models

Spojila sam laboratorijske eksperimente s računalnim modelima

and discovered that after most giant impacts,

i otkrila da je nakon većine velikih udara

the Earth is so hot, there's no surface.

Zemlja toliko vruća, da nema površine.

There's just a deep layer of gas that gets denser and denser with depth.

Postoji samo debeli sloj plina koji s dubinom postaje sve gušći.

The Earth would have been like Jupiter.

Zemlja je bila poput Jupitera.

There's nothing to stand on.

Bez čvrstog tla pod nogama.

And that was just part of the problem.

Ali to je bio samo dio problema.

I wanted to understand the whole problem.

Htjela sam potpuno razumjeti.

I couldn't let go of the challenge to figure out what was really going on

Nisam mogla odustati od izazova da otkrijem

što se zaista dogodi pri velikim udarima.

in giant impacts.

It took almost two years

Bile su potrebne gotovo dvije godine

of throwing away old ideas

odbacivanja starih rješenja

and building new ones

i stvaranja novih,

that we understood the data

da shvatimo podatke

and knew what it meant for the Moon.

i što to znači za Mjesec.

I discovered a new type of astronomical object.

Otkrila sam novu vrstu nebeskog tijela.

It's not a planet.

Nije planet.

It's made from planets.

Nastalo je od planeta.

A planet is a body whose self-gravity

Planet je tijelo čija je gravitacija

is strong enough to give it its rounded shape.

dovoljno snažna da mu daje okrugli oblik.

It spins around all together.

Sve zajedno rotira.

Make it hotter and spin it faster,

Ako mu povećavaš temperaturu i brzinu rotacije,

the equator gets bigger and bigger until it reaches a tipping point.

ekvator raste do točke u kojoj izgubi ravnotežu.

Push past the tipping point,

Ako ustrajemo iza te točke,

and the material at the equator spreads into a disk.

materijal na ekvatoru raširi se u prsten.

It's now broken all the rules of being a planet.

Prekršena su sva pravila kojima definiramo planet.

It can't spin around together anymore,

Ne može više rotirati zajedno,

its shape keeps changing as it gets bigger and bigger;

kako raste i raste, oblik mu se mijenja;

the planet has become something new.

planet preraste u nešto novo.

We gave our discovery its name:

Svom smo otkriću dali ime:

synestia.

sinestija.

We named it after the goddess Hestia,

Nazvali smo ga po božici Hestiji,

the Greek goddess of the hearth and home,

grčkoj božici ognjišta i doma,

because we think the Earth became one.

jer smatramo da je Zemlja postala upravo to.

The prefix means "all together,"

Prefiks ima značenje "zajedno",

to emphasize the connection between all of the material.

naglašava poveznicu čitavog materijala.

A synestia is what a planet becomes

Planet postane sinestija kad ga temperatura i rotacija

when heat and spin push it over the limit of a spheroidal shape.

izguraju izvan granica sferoidnog oblika.

Would you like to see a synestia?

Želite li vidjeti sinestiju?

(Cheers)

(Klicanje)

In this visualization of one of my simulations,

Na ovom prikazu jedne od mojih simulacija,

the young Earth is already spinning quickly from a previous giant impact.

mlada Zemlja već rotira brzo zbog prethodnog velikog udara.

Its shape is deformed, but our planet would be recognizable

Oblik joj je deformiran, ali moguće ju je prepoznati

by the water on its surface.

po vodi na njenoj površini.

The energy from the impact vaporizes the surface,

Energija udara pretvara u plin

površinu, vodu, atmosferu

the water, the atmosphere,

and mixes all of the gases together in just a few hours.

i izmiješa sve plinove za samo nekoliko sati.

We discovered that many giant impacts make synestias,

Otkrili smo da mnogi veliki udari stvaraju sinestije,

but these burning, bright objects don't live very long.

ali ova sjajna užarena tijela ne opstaju dugo.

They cool down, shrink and turn back into planets.

Ohlade se, stisnu i ponovno postanu planeti.

While rocky planets like Earth were growing,

Dok nastaju, stjenoviti planeti kao Zemlja

they probably turned into synestias one or more times.

vjerojatno se barem jednom pretvore u sinestiju.

A synestia gives us a new way to solve the problem of the origin of the Moon.

Sinestija nam pruža novo rješenje za problem postanka Mjeseca.

We propose that the Moon formed inside a huge, vaporous synestia.

Mi predlažemo da je Mjesec nastao unutar ogromne plinovite sinestije.

The Moon grew from magma rain

Nastao je iz kiše magme,

that condensed out of the rock vapor.

nastale kondenzacijom vaporiziranih stijena.

The Moon's special connection to Earth

Zemlja i Mjesec posebno su povezani

is because the Moon formed inside the Earth

jer je Mjesec nastao unutar Zemlje

when Earth was a synestia.

dok je Zemlja bila sinestija.

The Moon could have orbited inside the synestia for years,

Mjesec je mogao godinama orbitirati unutar sinestije,

hidden from view.

skriven.

The Moon is revealed by the synestia cooling and shrinking

Otkrilo ga je sinestijino hlađenje i stiskanje

inside of its orbit.

unutar vlastite orbite.

The synestia turns into planet Earth

Sinestija postaje planet Zemlja

only after cooling for hundreds of years longer.

tek nakon stotina godina hlađenja.

In our new theory,

Po našoj novoj teoriji,

the giant impact makes a synestia,

velikim udarom nastala je sinestija

and the synestia divides into two new bodies,

koja se razdijelila u dva nova tijela,

creating our isotopically identical Earth and Moon.

stvorivši izotopski identične Zemlju i Mjesec.

Synestias have been created throughout the universe.

Sinestije su nastajale po čitavom svemiru.

And we only just realized that by finding them in our imagination:

Shvatili smo to tek sada, pronašavši ih u našoj mašti.

What else am I missing in the world around me?

Što mi je još promaklo u svijetu koji me okružuje?

What is hidden from my view by my own assumptions?

Što još ne vidim zbog vlastitih pretpostavki?

The next time you look at the Moon,

Kada sljedeći put pogledate u Mjesec,

remember:

sjetite se:

the things you think you know

ono što mislite da znate

may be the opportunity to discover something truly amazing.

može biti prilika da otkrijete nešto stvarno nevjerojatno.

(Applause)

(Pljesak)