I saw a UFO once. I was eight or nine, playing in the street with a friend who was a couple of years older, and we saw a featureless silver disc hovering over the houses. We watched it for a few seconds, and then it shot away incredibly quickly. Even as a kid, I got angry it was ignoring the laws of physics. We ran inside to tell the grown-ups, and they were skeptical -- you'd be skeptical too, right? I got my own back a few years later: one of those grown-ups told me, "Last night I saw a flying saucer. I was coming out of the pub after a few drinks." I stopped him there. I said, "I can explain that sighting."
Video sam jednom NLO. Imao sam osam ili devet godina, igrao sam se na ulici sa drugom koji je bio par godina stariji, i videli smo običan srebrni disk kako lebdi iznad kuća. Gledali smo ga par sekundi, a onda je nestao neverovatno brzo. Čak i kao dete, iznervirao sam se jer je ignorisao zakone fizike. Utrčali smo unutra da kažemo odraslima, a oni su bili skeptični - vi biste isto bili skeptični, zar ne? Dobio sam svoje nekoliko godina kasnije, jedan od onih odraslih mi je rekao: "Sinoć sam video leteći tanjir. Izlazio sam iz paba nakon par pića." Zaustavio sam ga. Rekao sam: "Mogu ti objasniti to viđenje."
(Laughter)
(Smeh)
Psychologists have shown we can't trust our brains to tell the truth. It's easy to fool ourselves. I saw something, but what's more likely -- that I saw an alien spacecraft, or that my brain misinterpreted the data my eyes were giving it? Ever since though I've wondered: Why don't we see flying saucers flitting around? At the very least, why don't we see life out there in the cosmos? It's a puzzle, and I've discussed it with dozens of experts from different disciplines over the past three decades. And there's no consensus. Frank Drake began searching for alien signals back in 1960 -- so far, nothing. And with each passing year, this nonobservation, this lack of evidence for any alien activity gets more puzzling because we should see them, shouldn't we?
Psiholozi su pokazali da ne možemo da verujemo našim mozgovima da kažu istinu. Lako je da se prevarimo. Video sam nešto, ali šta je više verovatno - da sam video vanzemaljski svemirski brod, ili da je mozak loše protumačio podatke koje su mu moje oči davale? Još od tada se pitam: "Zašto ne vidimo leteće tanjire kako lete unaokolo?" Na kraju krajeva, zašto ne vidimo tragove života u kosmosu? To je zagonetka, a diskutovao sam sa desetinama eksperata iz različitih disciplina protekle tri decenije. I nema kosenzusa. Frenk Drejk je počeo potragu za vanzemaljskim signalima još 1960. - do sada, ništa. A sa svakom godinom koja prođe, ovo neposmatranje, nemanje dokaza ikakve vanzemaljske aktivnosti postaje još više zbunjujuće jer bi trebalo da ih vidimo, zar ne?
The universe is 13.8 billion years old, give or take. If we represent the age of the universe by one year, then our species came into being about 12 minutes before midnight, 31st December. Western civilization has existed for a few seconds. Extraterrestrial civilizations could have started in the summer months. Imagine a summer civilization developing a level of technology more advanced than ours, but tech based on accepted physics though, I'm not talking wormholes or warp drives -- whatever -- just an extrapolation of the sort of tech that TED celebrates. That civilization could program self-replicating probes to visit every planetary system in the galaxy. If they launched the first probes just after midnight one August day, then before breakfast same day, they could have colonized the galaxy. Intergalactic colonization isn't much more difficult, it just takes longer. A civilization from any one of millions of galaxies could have colonized our galaxy.
Univerzum ima 13,8 milijardi godina, manje više. Ako predstavimo starost univerzuma u jednoj godini, onda se naša vrsta stvorila oko 12 minuta pre ponoći, 31. decembra. Zapadna civilizacija postoji tek par sekundi. Vanzemaljske civilizacije su se mogle pokrenuti u letnjim mesecima. Zamislite letnju civilizaciju koja razvija tehnologiju napredniju od naše, ali tehnologiju zasnovanu na fizičkim zakonima, Ne govorim o crvotočini ili svetlosnim pogonima - bilo čemu - samo ekstrapolacija vrste tehnike koju TED slavi. Ta civilizacija bi mogla da isprogramira samokopirajuće sonde, da posete svaki planetarni sistem u galaksiji. Da lansiraju prve sonde posle ponoći jednog avgustovskog dana, pre doručka istog dana, bi oni mogli kolonizovati galaksiju. Intergalaktička kolonizacija nije mnogo teža, samo duže traje. Civilizacija iz bilo koje od miliona galaksija je mogla kolonizovati našu.
Seems far-fetched? Maybe it is, but wouldn't aliens engage in some recognizable activity -- put worldlets around a star to capture free sunlight, collaborate on a Wikipedia Galactica, or just shout out to the universe, "We're here"?
Izgleda neverovatno? Možda jeste, zar se ne bi vanzemaljci bavili nekom prepoznatljivom aktivnošću - stavljanjem malih svetova oko zvezde da uhvate slobodnu sunčevu svetlost, sarađivanjem na Vikipediji Galaktika, ili prosto da viknu svima: "Ovde smo"?
So where is everybody? It's a puzzle because we do expect these civilizations to exist, don't we? After all, there could be a trillion planets in the galaxy -- maybe more.
Pa gde su svi? Zagonetka je jer mi očekujemo da ove civilizacije postoje, zar ne? Uostalom, može postojati bilion planeta u galaksiji - možda i više.
You don't need any special knowledge to consider this question, and I've explored it with lots of people over the years. And I've found they often frame their thinking in terms of the barriers that would need to be cleared if a planet is to host a communicative civilization. And they usually identify four key barriers.
Ne treba vam nikakvo specijalno znanje da porazmislite o ovom pitanju, a ja sam istražio to sa dosta ljudi tokom godina. I ustanovio sam da oni često oblikuju svoje razmišljanje u smislu barijera koje bi se trebale probiti, ako je planeta ta koja ugošćava komunikativnu civilizaciju. A oni uglavnom identifikuju četiri ključne barijere.
Habitability -- that's the first barrier. We need a terrestrial planet in that just right "Goldilocks zone," where water flows as a liquid. They're out there. In 2016, astronomers confirmed there's a planet in the habitable zone of the closest star, Proxima Centauri -- so close that Breakthrough Starshot project plans to send probes there. We'd become a starfaring species. But not all worlds are habitable. Some will be too close to a star and they'll fry, some will be too far away and they'll freeze.
Habitabilnost - to je prva barijera. Treba nam suvozemna planeta na onaj "idealni" način, u kom voda struji kao tečnost. Oni su tamo. 2016. su astronomi potvrdili da postoji planeta u nastanjivoj zoni najbliže zvezde, Proksima Kentauri - toliko blizu da Brejktru Staršot projekat planira da pošalje sonde tamo. Postali bismo vrsta koja putuje svemirom. Ali nisu sve planete nastanjive. Neke će biti preblizu sunca i spržiće se, neke će biti predaleko i zalediće se.
Abiogenesis -- the creation of life from nonlife -- that's the second barrier. The basic building blocks of life aren't unique to Earth: amino acids have been found in comets, complex organic molecules in interstellar dust clouds, water in exoplanetary systems. The ingredients are there, we just don't know how they combine to create life, and presumably there will be worlds on which life doesn't start.
Abiogeneza - stvaranje života iz ne-života - to je druga barijera. Osnovni elementi života nisu jedinstveni za Zemlju: aminokiseline su pronađene u kometama, kompleksni organski molekuli u međuzvezdanim oblacima prašine, voda u egzoplanetarnim sistemima. Sastojci su tamo, samo ne znamo kako se kombinuju da bi se stvorio život, i po svojoj prilici biće planeta na kojima život ne počinje.
The development of technological civilization is a third barrier. Some say we already share our planet with alien intelligences. A 2011 study showed that elephants can cooperate to solve problems. A 2010 study showed that an octopus in captivity can recognize different humans. 2017 studies show that ravens can plan for future events -- wonderful, clever creatures -- but they can't contemplate the Breakthrough Starshot project, and if we vanished today, they wouldn't go on to implement Breakthrough Starshot -- why should they? Evolution doesn't have space travel as an end goal. There will be worlds where life doesn't give rise to advanced technology.
Razvoj tehnološke civilizacije je treća barijera. Neki kažu da mi već delimo planetu sa vanzemaljskim inteligencijama. Studije iz 2011. su pokazale da slonovi mogu da sarađuju da bi rešili probleme. Studije iz 2010. su pokazale da hobotnica u zatočeništvu može da prepozna različite ljude. Studije iz 2017. pokazuju da gavranovi mogu da planiraju za buduće događaje - čudesna, pametna stvorenja - ali oni ne mogu da razmišljaju o Brejktru Staršot projektu, a ako mi nestanemo danas, oni ne bi nastavili sa izvršavanjem Brejktru Staršota - zašto bi? Evolucija nema putovanje kroz svemir kao kranji cilj. Biće planeta gde život ne dostiže do napredne tehnologije.
Communication across space -- that's a fourth barrier. Maybe advanced civilizations choose to explore inner space rather than outer space, or engineer at small distances rather than large. Or maybe they just don't want to risk an encounter with a potentially more advanced and hostile neighbor. There'll be worlds where, for whatever reason, civilizations either stay silent or don't spend long trying to communicate.
Komunikacija duž svemira - to je četvrta barijera. Možda napredne civilizacije biraju da istražuju unutrašnji svemir radije nego spoljašnji svemir, ili izgrađuju na manjim razdaljinama više nego na većim. Ili možda samo neće da rizikuju da se susretnu sa potencijalno naprednijim i neprijateljski nastrojenim susedom. Biće planeta gde, iz kog god razloga, civilizacije bivaju neme ili ne provode puno pokušavajući da komuniciraju.
As for the height of the barriers, your guess is as good as anyone's. In my experience, when people sit down and do the math, they typically conclude there are thousands of civilizations in the galaxy. But then we're back to the puzzle: Where is everybody? By definition, UFOs -- including the one I saw -- are unidentified. We can't simply infer they're spacecraft. You can still have some fun playing with the idea aliens are here. Some say a summer civilization did colonize the galaxy and seeded Earth with life ... others, that we're living in a cosmic wilderness preserve -- a zoo. Yet others -- that we're living in a simulation. Programmers just haven't revealed the aliens yet. Most of my colleagues though argue that E.T. is out there, we just need to keep looking, and this makes sense. Space is vast. Identifying a signal is hard, and we haven't been looking that long. Without doubt, we should spend more on the search. It's about understanding our place in the universe. It's too important a question to ignore.
Što se tiče visine barijera, vaša pretpostavka je dobra kao i bilo čija. Po mom iskustvu, kad ljudi sednu i izračunaju, obično zaključe da ima hiljade civilizacija u galaksiji. Ali onda se vraćamo na zagonetku: gde su svi? Po definiciji, NLO-i - uključujući i onog kog sam ja video - su neidentifikovani. Ne možemo zaključivati da je to svemirski brod. Možete se malo zabaviti idejom da su vanzemaljci ovde. Neki kažu da je letnja civilizacija kolonizovala galaksiju i posejala život na Zemlji... drugi, da živimo u kosmičkoj očuvanoj divljini - u zoološkom vrtu. Međutim drugi - da živimo u simulaciji. Programeri nisu otkrili vanzemaljce još uvek. Većina mojih kolega se prepire o tome da su vanzemaljci tamo negde, samo treba da nastavimo potragu, a ovo ima smisla. Svemir je ogroman. Identifikovati signal je teško, a ne tražimo toliko dugo. Bez sumnje, treba da uložimo više na potragu. Radi se o razumevanju našeg mesta u univerzumu. Previše je važno pitanje da bi se ignorisalo.
But there's an obvious answer: we're alone. It's just us. There could be a trillion planets in the galaxy. Is it plausible we're the only creatures capable of contemplating this question? Well, yes, because in this context, we don't know whether a trillion is a big number. In 2000, Peter Ward and Don Brownlee proposed the Rare Earth idea. Remember those four barriers that people use to estimate the number of civilizations? Ward and Brownlee said there might be more.
Ali ima očiglednog odgovora: sami smo. Samo smo mi tu. Može postojati bilion planeta u galaksiji. Da li je moguće da smo jedina stvorenja sposobna da razmišljaju o ovom pitanju? Pa, da, jer u ovom kontekstu, ne znamo da li je bilion velik broj. Piter Vord i Don Braunli su 2000. predložili ideju "retke Zemlje". Sećate se one četiri barijere koje ljudi koriste da odrede broj civilizacija? Vord i Braunli su rekli da ih može biti više.
Let's look at one possible barrier. It's a recent suggestion by David Waltham, a geophysicist. This is my very simplified version of Dave's much more sophisticated argument. We are able to be here now because Earth's previous inhabitants enjoyed four billion years of good weather -- ups and downs but more or less clement. But long-term climate stability is strange, if only because astronomical influences can push a planet towards freezing or frying. There's a hint our moon has helped, and that's interesting because the prevailing theory is that the moon came into being when Theia, a body the size of Mars, crashed into a newly formed Earth. The outcome of that crash could have been a quite different Earth-Moon system. We ended up with a large moon and that permitted Earth to have both a stable axial tilt and a slow rotation rate. Both factors influence climate and the suggestion is that they've helped moderate climate change. Great for us, right? But Waltham showed that if the moon were just a few miles bigger, things would be different. Earth's spin axis would now wander chaotically. There'd be episodes of rapid climate change -- not good for complex life. The moon is just the right size: big but not too big. A "Goldilocks" moon around a "Goldilocks" planet -- a barrier perhaps.
Pogledajmo jednu moguću barijeru. To je skorašnji predlog Dejvida Volthema, geofizičara. Ovo je veoma pojednostavljena verzija Dejvidovog mnogo sofisticiranijeg argumenta. Mi smo u mogćnosti da budemo ovde sada jer su prethodni Zemljini stanovnici uživali u 4 milijarde godina lepog vremena - usponi i padovi ali manje više blago. Ali dugoročna klimatska stabilnost je čudna, zbog toga što astronomski uticaji mogu pogurati planetu ka zamrzavanju ili prženju. Ima nagoveštaja da je Mesec pomogao, a to je interesantno, jer je preovlađujuća teorija da se mesec pojavio kad se Tea, telo veličine Marsa, sudarila sa novoformiranom Zemljom. Ishod tog sudara mogao je da bude dosta drugačiji za sistem Zemlje i Meseca. Završili smo sa velikim mesecom, a to je dopustilo Zemlji da ima oba, stabilni nagib ose i sporu brzinu rotacije. Oba faktora utiču na klimu, a predlog je da su ti faktori pomogli u ublažavanju klimatskih promena. Odlično za nas, zar ne? Ali Volthem je pokazao da, u slučaju da je mesec veći, stvari bi bile drugačije. Zemljina rotaciona osa bi onda lutala haotično. Bilo bi epizoda brzih klimatskih promena - loše za kompleksni život. Mesec je baš prave veličine: velik, ali ne prevelik. "Idealni" Mesec oko "idealne" planete - možda je to barijera.
You can imagine more barriers. For instance, simple cells came into being billions of years ago ... but perhaps the development of complex life needed a series of unlikely events. Once life on Earth had access to multicellularity and sophisticated genetic structures, and sex, new opportunities opened up: animals became possible. But maybe it's the fate of many planets for life to settle at the level of simple cells.
Možete zamisliti još barijera. Na primer, jednoćelijski organizmi su se ostvarili pre milijardu godina... ali možda je za razvoj kompleksnog života potreban niz neizvesnih događaja. Čim je život na Zemlji pristupio višećelijskim organizmima, sofisticiranim genetskim strukturama, i seksu, nove mogućnosti su se otvorile: životinje su postale moguće. Ali možda je to sudbina mnogih planeta, da se život nastani na stepenu jednoćelijskih organizama.
Purely for the purposes of illustration, let me suggest four more barriers to add to the four that people said blocked the path to communicative civilization. Again, purely for the purposes of illustration, suppose there's a one-in-a-thousand chance of making it across each of the barriers. Of course there might be different ways of navigating the barriers, and some chances will be better than one in a thousand. Equally, there might be more barriers and some chances might be one in a million. Let's just see what happens in this picture.
Čisto radi ilustracije, dozovlite mi da predložim četiri dodatne barijere na one četiri, za koje ljudi kažu da blokiraju put ka komunikativnoj civilizaciji. Ponovo, čisto radi ilustracije, pretpostavimo šanse jedan naprema hiljadu za prevazilaženje svake od barijera. Naravno, možda postoje drugačiji načini upravljanja barijerama, i neke će šanse biti bolje od jedan naprema hiljadu. Podjednako, može biti još barijera, a neke su šanse možda i jedan u milion. Da vidimo šta se dešava u ovom slučaju.
If the galaxy contains a trillion planets, how many will host a civilization capable of contemplating like us projects such as Breakthrough Starshot? Habitability -- right sort of planet around the right sort of star -- the trillion becomes a billion. Stability -- a climate that stays benign for eons -- the billion becomes a million. Life must start -- the million becomes a thousand. Complex life forms must arise -- the thousand becomes one. Sophisticated tool use must develop -- that's one planet in a thousand galaxies. To understand the universe, they'll have to develop the techniques of science and mathematics -- that's one planet in a million galaxies. To reach the stars, they'll have to be social creatures, capable of discussing abstract concepts with each other using complex grammar -- one planet in a billion galaxies. And they have to avoid disaster -- not just self-inflicted but from the skies, too. That planet around Proxima Centauri, last year it got blasted by a flare. One planet in a trillion galaxies, just as in the visible universe.
Ako galaksija sadrži bilion planeta, koliko njih će ugostiti civilizaciju sposobnu da razmišlja poput nas, projekte kao što je Brejktru Staršot? Habitabilnost - prava vrsta planete oko prave vrste zvezde - bilion postaje milijarda. Stabilnost - klima koja ostaje benigna eonima - milijarda postaje milion. Život mora početi - milion postaje hiljadu. Kompleksni oblici života moraju izniknuti - hiljadu postaje jedan. Prefinjeno korišćenje alatki se mora razviti - to je jedna planeta u hiljadu galaksija. Da bi razumeli univerzum, moraće da razviju tehnike nauke i matematike - to je jedna planeta u milion galaksija. Da bi doprli do zvezda, moraće da budu socijalna bića, u stanju da diskutuju o apstraktnim konceptima među sobom koristeći kompleksnu gramatiku - jedna planeta u milijardu galaksija. I moraju da izbegavaju nepogode - ne samo koje su sami sebi naneli, nego i one sa neba takođe. Ona planeta oko Proksima Kentauri, prošle godine ju je bljesak razneo. Jedna planeta u bilion galaksija, baš kao u vidljivom univerzumu.
I think we're alone. Those colleagues of mine who agree we're alone often see a barrier ahead -- bioterror, global warming, war. A universe that's silent because technology itself forms the barrier to the development of a truly advanced civilization. Depressing, right?
Ja mislim da smo sami. Te moje kolege koje se slažu da smo sami, često vide barijeru unapred - bioteror, globalno zagrevanje, rat. Univerzum koji je nem, jer sama tehnologija formira barijeru razvitku zaista napredne civilizacije. Obeshrabrujuće, zar ne?
I'm arguing the exact opposite. I grew up watching "Star Trek" and "Forbidden Planet," and I saw a UFO once, so this idea of cosmic loneliness I certainly find slightly wistful. But for me, the silence of the universe is shouting, "We're the creatures who got lucky." All barriers are behind us. We're the only species that's cleared them -- the only species capable of determining its own destiny. And if we learn to appreciate how special our planet is, how important it is to look after our home and to find others, how incredibly fortunate we all are simply to be aware of the universe, humanity might survive for a while. And all those amazing things we dreamed aliens might have done in the past, that could be our future.
Ja argumentujem potpuno suprotno. Odrastao sam gledajući "Star Trek" i "Zabranjenu planetu", i video sam NLO jednom, stoga ideju kosmičke usamljenosti smatram pomalo sumornom. Ali za mene, tišina univerzuma viče: "Mi smo bića kojim se posrećilo." Sve barijere su iza nas. Jedina smo vrsta koja ih je probila - jedina vrsta sposobna da odredi sopstvenu sudbinu. I ako naučimo da cenimo koliko je posebna naša planeta, koliko je važno da pazimo našu kuću, i da nađemo ostale, koliki smo svi mi neverovatni srećnici da prosto budemo svesni univerzuma, čovečanstvo možda preživi još neko vreme. I sve te zapanjujuće stvari koje smo sanjali da su vanzemaljci možda uradili u prošlosti, bi mogle biti naša budućnost.
Thank you very much.
Hvala vam puno.
(Applause)
(Aplauz)