Nobody likes to make a mistake. And I made a whopping one. And figuring out what I did wrong led to a discovery that completely changes the way we think about the Earth and Moon.
Niko ne voli da greši. A ja sam napravila ogromnu grešku. A razumevanje u čemu sam pogrešila je dovelo do otkrića koje u potpunosti menja način na koji razmišljamo o Zemlji i Mesecu.
I'm a planetary scientist, and my favorite thing to do is smash planets together.
Ja sam planetarna naučnica i omiljena aktivnost mi je da izazivam sudare planeta.
(Laughter)
(Smeh)
In my lab, I can shoot at rocks using cannons like this one.
U mojoj laboratoriji, mogu da pucam u stene pomoću ovakvih topova.
(Cannon shot)
(Pucanj topa)
(Laughter)
(Smeh)
In my experiments, I can generate the extreme conditions during planet formation. And with computer models, I can collide whole planets together to make them grow, or I can destroy them.
U mojim eksperimentima, mogu da stvorim ekstremne uslove prisutne tokom nastanka planete. A uz pomoć kompjuterskih modela, mogu da sudaram čitave planete kako bih izazvala njihov rast ili mogu da ih uništim.
(Laughter)
(Smeh)
I want to understand how to make the Earth and the Moon and why the Earth is so different from other planets.
Želim da razumem kako da napravim Zemlju i Mesec i zašto je Zemlja toliko različita od drugih planeta.
The leading idea for the origin of the Earth and Moon is called the "giant impact theory." The theory states that a Mars-sized body struck the young Earth, and the Moon formed from the debris disk around the planet. The theory can explain so many things about the Moon, but it has a huge flaw: it predicts that the Moon is mostly made from the Mars-sized planet, that the Earth and the Moon are made from different materials. But that's not what we see. The Earth and the Moon are actually like identical twins. The genetic code of planets is written in the isotopes of the elements. The Earth and Moon have identical isotopes. That means that the Earth and Moon are made from the same materials.
Vodeća ideja o nastanku Zemlje i Meseca se naziva „teorijom velikog udara”. Teorija tvrdi da je telo veličine Marsa udarilo mladu Zemlju i da je Mesec nastao od diska formiranog od otpadaka oko planete. Ova teorija može da objasni toliko toga u vezi s Mesecom, ali ima ogromni nedostatak: predviđa da se Mesec uglavnom sastoji od planete veličine Marsa i da su Zemlja i Mesec sačinjeni od različitih materijala. Međutim, to nije ono što vidimo. Zemlja i Mesec su zapravo poput identičnih blizanaca. Genetski kod planeta je zapisan u izotopima elemenata. Zemlja i Mesec imaju identične izotope. To znači da su Zemlja i Mesec sačinjeni od istog materijala.
It's really strange that the Earth and the Moon are twins. All of the planets are made from different materials, so they all have different isotopes, they all have their own genetic code. No other planetary bodies have the same genetic relationship. Only the Earth and Moon are twins.
Zaista je čudno da su Zemlja i Mesec blizanci. Sve planete su sačinjene od različitih materijala, stoga sve imaju različite izotope, sve imaju sopstvene genetske kodove. Ne postoje druga planetarna tela koja imaju istu genetsku vezu. Samo su Zemlja i Mesec blizanci.
When I started working on the origin of the Moon, there were scientists that wanted to reject the whole idea of the giant impact. They didn't see any way for this theory to explain the special relationship between the Earth and the Moon. We were all trying to think of new ideas. The problem was, there weren't any better ideas. All of the other ideas had even bigger flaws. So we were trying to rescue the giant impact theory.
Kada sam počela da radim na poreklu Meseca, postojali su naučnici koju su želeli da odbace čitavu ideju velikog udara. Nisu videli način na koji ova teorija može da objasni posebnu vezu između Zemlje i Meseca. Svi smo pokušavali da smislimo nove ideje. Problem je bio što nije bilo boljih ideja. Sve druge ideje su imale čak i krupnije nedostatke. Pa smo pokušavali da spasimo teoriju velikog udara.
A young scientist in my group suggested that we try changing the spin of the giant impact. Maybe making the Earth spin faster could mix more material and explain the Moon. The Mars-sized impactor had been chosen because it could make the Moon and make the length of Earth's day. People really liked that part of the model. But what if something else determined the length of Earth's day? Then there would be many more possible giant impacts that could make the Moon. I was curious about what could happen, so I tried simulating faster-spinning giant impacts, and I found that it is possible to make a disk out of the same mixture of materials as the planet. We were pretty excited. Maybe this was the way to explain the Moon.
Mladi naučnik iz moje grupe je predložio da pokušamo da izmenimo obrtanje prilikom velikog udara. Možda je Zemljino brže okretanje moglo da izmeša više materijala i tako objasni Mesec. Odabran je sudarač veličine Marsa jer je mogao da napravi Mesec i da uzrokuje dužinu dana na Zemlji. Ljudima se zaista sviđao taj deo modela. Međutim, šta ako je nešto drugo odredilo dužinu dana na Zemlji? Onda bi postojalo mnogo više mogućih velikih udara koji su mogli da stvore Mesec. Zanimalo me je šta bi moglo da se desi, pa sam pokušala da simuliram velike udare brže rotacije i otkrila sam da je moguće napraviti disk od iste smeše materijala kao u slučaju planete. Bili smo prilično uzbuđeni. Možda je ovo bio način da se objasni Mesec.
The problem is, we also found that that's just not very likely. Most of the time, the disk is different from the planet, and it looked like making our Moon this way would be an astronomical coincidence, and it was just hard for everyone to accept the idea that the Moon's special connection to Earth was an accident. The giant impact theory was still in trouble, and we were still trying to figure out how to make the Moon.
Problem je bio što smo takođe otkrili da to nije naročito verovatno. Većinu vremena, disk je različit od planete i činilo se da bi ovakav nastanak Meseca bio astronomska slučajnost, a bilo je prosto svima teško da prihvate ovu ideju da je Mesečeva posebna veza sa Zemljom slučajna. Teorija o velikom udaru je i dalje bila u nevolji, a mi smo i dalje pokušavali da otkrijemo kako da napravimo Mesec.
Then came the day when I realized my mistake. My student and I were looking at the data from these fast-spinning giant impacts. On that day, we weren't actually thinking about the Moon, we were looking at the planet. The planet gets super-hot and partially vaporized from the energy of the impact. But the data didn't look like a planet. It looked really strange. The planet was weirdly connected to the disk. I got that super-excited feeling when something really wrong might be something really interesting.
Onda je došao dan kad sam uvidela svoju grešku. Moj student i ja smo posmatrali podatke o ovim brzorotirajućim velikim udarima. Tog dana, zapravo nismo razmišljali o Mesecu, posmatrali smo planetu. Planeta postaje veoma vrela i delimično isparava od energije udarca. Međutim, podaci nisu ličili na planetu. Izgledali su veoma čudno. Planeta je neobično bila povezana s diskom. Javio mi se onaj superuzbudljivi osećaj kada nešto krajnje pogrešno može da bude nešto krajnje zanimljivo.
In all of my calculations, I had assumed there was a planet with a separate disk around it. Calculating what was in the disk as how we tested whether an impact could make the Moon. But it didn't look that simple anymore. We were making the mistake of thinking that a planet was always going to look like a planet. On that day, I knew that a giant impact was making something completely new.
U svim mojim proračunima, pretpostavila sam postojanje planete sa odvojenim diskovima oko sebe. Računanjem sastava diska smo testirali da li je udar mogao da stvori Mesec. Međutim, više se nije činilo tako prosto. Pravili smo grešku smatrajući da će planeta uvek da izgleda kao planeta. Tog dana, znala sam da veliki udar stvara nešto sasvim novo.
I've had eureka moments. This was not one of them.
Imala sam trenutke eureke. Ovo nije bio jedan od njih.
(Laughter)
(Smeh)
I really didn't know what was going on. I had this strange, new object in front of me and the challenge to try and figure it out. What do you do when faced with the unknown? How do you even start?
Zaista nisam znala šta se zbivalo. Imala sam taj čudni, novi objekat ispred sebe, kao i izazov da pokušam da ga razumem. Šta radite kada se suočite sa nepoznatim? Kako uopšte da otpočnete?
We questioned everything: What is a planet? When is a planet no longer a planet anymore? We played with new ideas. We had to get rid of our old way of thinking, and by playing, I could throw away all of the data, all of the rules of the real world, and free my mind to explore. And by making a mental space where I could try out outrageous ideas and then bring them back into the real world to test them, I could learn. And by playing, we learned so much. I combined my lab experiments with computer models and discovered that after most giant impacts, the Earth is so hot, there's no surface. There's just a deep layer of gas that gets denser and denser with depth. The Earth would have been like Jupiter. There's nothing to stand on. And that was just part of the problem. I wanted to understand the whole problem. I couldn't let go of the challenge to figure out what was really going on in giant impacts. It took almost two years of throwing away old ideas and building new ones that we understood the data and knew what it meant for the Moon.
Sve smo dovodili u pitanje: šta je planeta? Kada planeta više nije planeta? Poigravali smo se s novim idejama. Morali smo se otarasiti starog načina razmišljanja i poigravajući se, mogla sam da odbacim sve podatke, sva pravila stvarnog sveta i oslobodim um da istražuje. A stvarajući mentalni prostor na kom sam mogla da isprobavam skandalozne ideje i da ih potom vratim u stvarni svet radi testiranja, bila sam u stanju da učim. A poigravajući se, naučili smo toliko toga. Kombinovala sam eksperimente iz laboratorije sa kompjuterskim modelima i otkrila sam da je nakon većine velikih udara Zemlja toliko vrela da nema površinu. Postoji samo duboki sloj gasa koji postaje sve gušći sa dubinom. Zemlja bi izgledala kao Jupiter. Bez ičega na šta biste stali. A to je tek bio deo problema. Želela sam da razumem čitav problem. Nisam mogla da odustanem od izazova razumevanja šta se zaista zbiva tokom velikih udara. Trebalo nam je skoro dve godine odbacivanja starih ideja i stvaranja novih da razumemo podatke i shvatimo šta to znači za Mesec.
I discovered a new type of astronomical object. It's not a planet. It's made from planets. A planet is a body whose self-gravity is strong enough to give it its rounded shape. It spins around all together. Make it hotter and spin it faster, the equator gets bigger and bigger until it reaches a tipping point. Push past the tipping point, and the material at the equator spreads into a disk. It's now broken all the rules of being a planet. It can't spin around together anymore, its shape keeps changing as it gets bigger and bigger; the planet has become something new.
Otkrila sam novi tip astronomskog objekta. Ne radi se o planeti. Sačinjen je od planeta. Planeta je telo čija je sopstvena gravitacija dovoljno jaka da mu podari sferni oblik. Vrti se u celosti oko sebe. Ukoliko postane toplija i vrti se brže, ekvator postaje sve veći dok ne dosegne prelomnu tačku. Pogurajte je preko prelomne tačke i materijal u predelu ekvatora se širi i postaje disk. U tom trentuku krši sva pravila koja je čine planetom. Više ne može u celosti da se obrće oko sebe, oblik joj se sve više menja kako postaje sve veća; planeta je postala nešto sasvim novo.
We gave our discovery its name: synestia. We named it after the goddess Hestia, the Greek goddess of the hearth and home, because we think the Earth became one. The prefix means "all together," to emphasize the connection between all of the material. A synestia is what a planet becomes when heat and spin push it over the limit of a spheroidal shape.
Imenovali smo naše otkriće: sinestija. Imenovali smo ga po boginji Hestiji, grčkoj boginji ognjišta i doma jer smatramo da je Zemlja postala dom. Prefiks znači „sveukupno”, kako bi se naglasila veza između svih materijala. Sinestija je ono što planeta postaje kada je toplota i obrtanje odgurnu mimo granica sfernog oblika.
Would you like to see a synestia?
Da li biste želeli da vidite sinestiju?
(Cheers)
(Klicanje)
In this visualization of one of my simulations, the young Earth is already spinning quickly from a previous giant impact. Its shape is deformed, but our planet would be recognizable by the water on its surface. The energy from the impact vaporizes the surface, the water, the atmosphere, and mixes all of the gases together in just a few hours. We discovered that many giant impacts make synestias, but these burning, bright objects don't live very long. They cool down, shrink and turn back into planets. While rocky planets like Earth were growing, they probably turned into synestias one or more times.
U ovoj vizualizaciji jedne od mojih simulacija, mlada Zemlja se već obrće brzo zbog prethodnog velikog udara. Izobličena je, ali je naša planeta i dalje prepoznatljiva po vodi na površini. Zbog energije od udara, njena površina isparava, voda, atmosfera. I svi gasovi se međusobno izmešaju za svega nekoliko sati. Otkrili smo da mnogi veliki udari stvaraju sinestije, ali ovi plamteći, jarki objekti ne žive dugo. Hlade se, skupljaju i ponovo postaju planete. Dok su stenovite planete, poput Zemlje, rasle, verovatno su postajale sinestije jednom ili više puta.
A synestia gives us a new way to solve the problem of the origin of the Moon. We propose that the Moon formed inside a huge, vaporous synestia. The Moon grew from magma rain that condensed out of the rock vapor. The Moon's special connection to Earth is because the Moon formed inside the Earth when Earth was a synestia. The Moon could have orbited inside the synestia for years, hidden from view. The Moon is revealed by the synestia cooling and shrinking inside of its orbit. The synestia turns into planet Earth only after cooling for hundreds of years longer. In our new theory, the giant impact makes a synestia, and the synestia divides into two new bodies, creating our isotopically identical Earth and Moon. Synestias have been created throughout the universe. And we only just realized that by finding them in our imagination: What else am I missing in the world around me? What is hidden from my view by my own assumptions?
Sinestija nam pruža novi način rešavanja problema nastanka Meseca. Naša je pretpostavka da je Mesec oblikovan unutar ogromne, isparavajuće sinestije. Mesec je rastao zbog kiša od magme koje su se kondenzovale iz isparavanja stena. Mesečeva posebna veza sa Zemljom postoji zato što je Mesec nastao unutar Zemlje kada je Zemlja bila sinestija. Mesec je mogao da kruži unutar sinestije godinama, skriven od pogleda. Mesec je otkriven tokom sinestijinog hlađenja i skupljanja unutar njene orbite. Sinestija se pretvorila u planetu Zemlju tek nakon što se hladila još stotinama godina. U našoj novoj teoriji, veliki udar stvara sinestiju, a sinestija se cepa u dva nova tela, stvarajući našu Zemlju i Mesec koji su izotopski identični. Sinestije su nastajale širom univerzuma. A mi smo to tek sad shvatili, otkrivajući ih u našoj mašti. Šta mi i dalje promiče u svetu koji me okružuje? Šta mi se skriva od pogleda zbog mojih sopstvenih pretpostavki?
The next time you look at the Moon, remember: the things you think you know may be the opportunity to discover something truly amazing.
Sledeći put kada pogledate u Mesec, setite se: stvari koje mislite da znate mogu da budu prilike da otkrijete nešto istinski zadivljujuće.
(Applause)
(Aplauz)