The Fermi Paradox — Where Are All The Aliens? (1/2) Das Fermi-Paradoxon - Wo sind all die Außerirdischen? (1/2) La paradoja de Fermi - ¿Dónde están los extraterrestres? (1/2) フェルミのパラドックス - エイリアンはどこにいるのか (1/2) Fermio paradoksas - kur yra visi ateiviai? (1/2) Paradoks Fermiego - gdzie są wszyscy kosmici? (1/2) O Paradoxo de Fermi - Onde estão os extraterrestres? (1/2) Парадокс Ферми - где все инопланетяне? (1/2) Fermi Paradoksu - Uzaylılar Nerede? (1/2) Парадокс Фермі - де всі інопланетяни? (1/2) 费米悖论——外星人都在哪里？ (1/2)

Are we the only living things in the entire universe? Seremos nós os únicos seres vivos em todo o universo? Мы единственные живые существа во всей вселенной? Tüm evrende yaşayan tek canlı biz miyiz?

The observable universe is about 90 billion light years in diameter. O universo observável tem cerca de 90 bilhões de anos-luz de diâmetro. Gözlemlenebilir evrenin çapı yaklaşık 90 milyar ışık yılıdır. 可观测宇宙的直径约为 900 亿光年。

There are at least one hundred billion galaxies, each with one hundred to one thousand billion stars. Existem pelo menos cem bilhões de galáxias, cada uma com cem a mil bilhões de estrelas. Есть по крайней мере сто миллиардов галактик, в каждой от ста до тысячи миллиардов звезд. Her birinde yüz ila bin milyar yıldız bulunan en az yüz milyar galaksi vardır.

Recently, we've learned that planets are very common too. Kürzlich haben wir erfahren, dass auch Planeten sehr häufig sind. Recently, we've learned that planets are very common too. Недавно мы узнали, что планеты тоже очень распространены. Son zamanlarda gezegenlerin de çok yaygın olduğunu öğrendik.

And, there are probably trillions and trillions of habitable planets in the universe. Et il y a probablement des billions et des billions de planètes habitables dans l'univers. E provavelmente existem trilhões e trilhões de planetas habitáveis no universo. Ve muhtemelen evrende trilyonlarca ve trilyonlarca yaşanabilir gezegen var.

Which means, there should be lots of opportunity for life to develop and exist, right? Bu da yaşamın gelişmesi ve var olması için çok fazla fırsat olması gerektiği anlamına geliyor, değil mi?

But where is it? Ama nerede?

Shouldn't the universe be teeming with spaceships? Shouldn't the universe be teeming with spaceships? L'univers ne devrait-il pas regorger de vaisseaux spatiaux ? O universo não deveria estar repleto de naves espaciais? Разве Вселенная не должна кишеть космическими кораблями? Evrenin uzay gemileriyle dolu olması gerekmez mi? 宇宙不应该充满宇宙飞船吗？

Let's take a step back. Vamos dar um passo para trás. Bir adım geri gidelim.

Even if there are alien civilizations in other galaxies, Başka galaksilerde uzaylı uygarlıklar olsa bile,

There's no way we'll ever know about them. Wir werden nie etwas über sie erfahren. Não há como sabermos sobre eles. Onları öğrenmemizin imkanı yok.

Basically, everything outside of our direct galactic neighborhood, Basicamente, tudo fora da nossa vizinhança galáctica direta, Temel olarak, doğrudan galaktik komşuluğumuzun dışındaki her şey,

the so called "Local Group", is pretty much out of our reach forever, el llamado "Grupo Local", está prácticamente fuera de nuestro alcance para siempre, o chamado "Grupo Local", está praticamente fora do nosso alcance para sempre, "Yerel Grup" olarak adlandırılan grup, sonsuza dek erişemeyeceğimiz bir yerde, 所谓的“本地组”，几乎是我们永远无法企及的，

because of the expansion of the universe. por causa da expansão do universo. Çünkü evren genişliyor.

Even if we had really fast spaceships,

it would literally take billions of years to reach these places, чтобы добраться до этих мест, потребуются буквально миллиарды лет,

traveling through the emptiest areas in the universe. viajando pelas áreas mais vazias do universo. путешествуя по самым пустынным областям Вселенной. 穿越宇宙中最空旷的区域。

So, let's focus on the Milky Way. 所以，让我们专注于银河系。

The Milky Way is our home galaxy. A Via Láctea é a nossa galáxia natal.

It consists of up to four hundred billion stars. Consiste em até quatrocentos bilhões de estrelas.

That's a lot of stars, roughly ten thousand for every grain of sand on earth. Das sind eine Menge Sterne, etwa zehntausend für jedes Sandkorn auf der Erde. Son muchas estrellas, unas diez mil por cada grano de arena de la Tierra. Cela fait beaucoup d'étoiles, environ dix mille pour chaque grain de sable sur terre. Isso é um monte de estrelas, cerca de dez mil para cada grão de areia na Terra. Это много звезд, примерно десять тысяч на каждую песчинку на земле.

There are about twenty billion sunlike stars in the Milky Way, La Voie lactée compte environ vingt milliards d'étoiles semblables à des soleils, Existem cerca de vinte bilhões de estrelas semelhantes ao Sol na Via Láctea,

and estimates suggest that a fifth of them, have an earth sized planet in it's habitable zone, et les estimations suggèrent qu'un cinquième d'entre elles possèdent une planète de la taille de la Terre dans sa zone habitable, e as estimativas sugerem que um quinto deles tem um planeta do tamanho da Terra em sua zona habitável, и по оценкам, пятая из них имеет планету размером с Землю в своей обитаемой зоне, 并且估计表明其中五分之一在其宜居带中有一个地球大小的行星，

the area with conditions that enable life to exist. a área com condições que permitem a existência de vida. 具有使生命存在的条件的区域。

If only 0.1% of those planets harbored life, there would be one million planets with life in the milky way. Se apenas 0,1% desses planetas abrigassem vida, haveria um milhão de planetas com vida na via láctea. 如果这些行星中只有 0.1% 存在生命，那么银河系中将有 100 万颗行星存在生命。

But wait, there's more.

The Milky Way is about thirteen billion years old. In the beginning, it would not have been a good place for life, La Voie lactée a environ treize milliards d'années. Au début, elle n'aurait pas été un endroit propice à la vie, 银河系大约有 130 亿年的历史。一开始，它不会是一个适合生活的地方，

because things exploded a lot. But after one to two billion years, the first habitable planet was born. denn es gab viele Explosionen. Aber nach ein bis zwei Milliarden Jahren wurde der erste bewohnbare Planet geboren. porque as coisas explodiram muito. Mas depois de um a dois bilhões de anos, nasceu o primeiro planeta habitável.

Earth is only four billions years old, so there have probably been trillions of chances for life to develop on other planets in the past. 地球只有四十亿年的历史，因此过去可能有数万亿次生命在其他星球上发展的机会。

If only a single one of them had developed into a space traveling super civilization, we would have noticed by now. Si una sola de ellas se hubiera convertido en una supercivilización que viajara por el espacio, ya nos habríamos dado cuenta. Si un seul d'entre eux s'était transformé en une super civilisation voyageant dans l'espace, nous l'aurions déjà remarqué. Se apenas um deles tivesse se desenvolvido em uma supercivilização espacial, já teríamos notado. 如果他们中只有一个人发展成为太空旅行的超级文明，我们现在已经注意到了。

What would such a civilization look like? ¿Cómo sería una civilización así? Como seria tal civilização?

There are three categories.

A type one civilization would be able to access the whole energy available on its planet. Una civilización de tipo uno sería capaz de acceder a toda la energía disponible en su planeta. Une civilisation de type 1 serait capable d'accéder à toute l'énergie disponible sur sa planète. Цивилизация первого типа сможет получить доступ ко всей энергии, доступной на ее планете. 第一类文明将能够获取其星球上可用的全部能量。

In case you are wondering, we are currently around zero point seven three on the scale, Falls Sie sich wundern, wir stehen derzeit bei null Komma sieben drei auf der Skala, En caso de que se lo pregunte, actualmente estamos en torno al cero coma siete tres en la escala, Au cas où vous vous poseriez la question, nous nous situons actuellement à zéro virgule sept trois sur l'échelle, Caso você esteja se perguntando, estamos atualmente em torno de zero vírgula sete três na escala, Если вам интересно, в настоящее время мы находимся около нуля целых семь десятых десятых долей шкалы, 如果您想知道，我们目前的规模大约为零点七三，

and we should reach type one sometime in the next couple hundred years. y deberíamos alcanzar el tipo uno en algún momento de los próximos doscientos años. e devemos alcançar o tipo um em algum momento nos próximos duzentos anos. 我们应该在未来几百年的某个时候达到类型一。

Type two would be a civilization capable of harnessing all of the energy of its home star. El tipo dos sería una civilización capaz de aprovechar toda la energía de su estrella natal. Le deuxième type serait une civilisation capable d'exploiter toute l'énergie de son étoile d'origine. O tipo dois seria uma civilização capaz de aproveitar toda a energia de sua estrela natal. 第二类将是一个能够利用其母星所有能量的文明。

This would require some serious science fiction, but it is doable in principle. Cela nécessiterait un peu de science-fiction, mais c'est en principe faisable. Isso exigiria alguma ficção científica séria, mas é factível em princípio. Для этого потребуется серьезная научная фантастика, но в принципе это выполнимо. 这需要一些严肃的科幻小说，但原则上是可行的。

Concepts like the Dyson Sphere, a giant complex surrounding the sun, would be conceivable. Conceptos como la Esfera de Dyson, un complejo gigante que rodea al sol, serían concebibles. Des concepts tels que la sphère de Dyson, un complexe géant entourant le soleil, seraient concevables. Conceitos como a Esfera Dyson, um complexo gigante em torno do sol, seriam concebíveis. 像戴森球这样的概念，一个围绕太阳的巨大复合体，是可以想象的。

Type three is a civilization that basically controls it's whole galaxy and its energy Le troisième type est une civilisation qui contrôle l'ensemble de sa galaxie et son énergie. 第三类是一种基本控制整个银河系及其能量的文明

An alien race this advanced would probably be godlike to us. Una raza alienígena tan avanzada probablemente sería divina para nosotros. Une race extraterrestre aussi avancée serait probablement un dieu pour nous. Uma raça alienígena tão avançada provavelmente seria divina para nós. Столь развитая инопланетная раса, вероятно, была бы для нас богоподобной. 这种先进的外星种族对我们来说可能是神一样的。

But why should we be able to see such an alien civilization in the first place? Aber warum sollten wir überhaupt in der Lage sein, eine solche außerirdische Zivilisation zu sehen? Pero, ¿para qué íbamos a poder ver una civilización tan extraterrestre? Mais pourquoi devrions-nous être en mesure de voir une telle civilisation extraterrestre ? Mas por que deveríamos ser capazes de ver uma civilização tão alienígena em primeiro lugar?

If we were to build generation spaceships that could sustain a population for around one-thousand years, Si construyéramos naves espaciales generacionales que pudieran mantener una población durante unos mil años, Si nous construisions des vaisseaux spatiaux de nouvelle génération capables d'accueillir une population pendant environ mille ans, Se construíssemos naves espaciais de geração que pudessem sustentar uma população por cerca de mil anos, 如果我们要建造可以维持人口大约一千年的世代宇宙飞船，

we could colonize the whole galaxy in two million years. 我们可以在两百万年内殖民整个银河系。

Sounds like a long time, but remember, the milky way is huge. Похоже, давно, но помните, Млечный путь огромен.

So, if it takes a couple of million years to colonize the entire galaxy, 所以，如果殖民整个银河系需要几百万年，

and there are possibly millions, if not billions of planets that sustain life in the Milky Way, et il y a peut-être des millions, voire des milliards de planètes qui abritent la vie dans la Voie lactée, 银河系中可能有数百万甚至数十亿的行星维持生命，

and these other life forms have had considerably more time than we've had, then... 而这些其他生命形式比我们拥有的时间要多得多，那么……

Where are all the aliens? 所有的外星人都在哪里？

This, is the Fermi Paradox, and nobody has an answer to it. Это парадокс Ферми, и ни у кого нет ответа. 这就是费米悖论，没有人能回答。

But we do have some ideas. Pero tenemos algunas ideas.

Let's talk about filters. Hablemos de filtros.

A filter in this context represents a barrier that is really hard for life to overcome. Dans ce contexte, un filtre représente un obstacle que la vie a beaucoup de mal à franchir. Um filtro neste contexto representa uma barreira muito difícil de ser superada pela vida. 在这种情况下，过滤器代表了生命真正难以克服的障碍。

They come in various degrees of scary. Los hay de varios grados de miedo. Eles vêm em vários graus de assustador. 他们有不同程度的可怕。

One: There are Great Filters and we've passed them. Erstens: Es gibt große Filter, und wir haben sie überwunden. Uno: Hay Grandes Filtros y los hemos pasado. Premièrement : il existe de grands filtres et nous les avons dépassés. Um: Existem Grandes Filtros e nós passamos por eles. Первый: есть отличные фильтры, и мы их прошли. 一：有很棒的过滤器，我们已经通过了它们。

Maybe it is way harder for complex life to develop then we think. Tal vez sea mucho más difícil que se desarrolle vida compleja de lo que pensamos. Il est peut-être beaucoup plus difficile de développer une vie complexe que nous ne le pensons. 也许复杂的生命比我们想象的更难发展。

The process, allowing life to begin, hasn't yet been completely figured out, Der Prozess, der die Entstehung von Leben ermöglicht, ist noch nicht vollständig erforscht, El proceso que permite que comience la vida aún no se ha descifrado por completo, Le processus qui permet à la vie de commencer n'a pas encore été complètement élucidé, Процесс, позволяющий зародиться жизни, еще полностью не выяснен, 这个过程，让生命开始，还没有完全弄清楚，

and the conditions required may be really complicated. und die erforderlichen Bedingungen können sehr kompliziert sein. 而且所需的条件可能真的很复杂。

Maybe in the past, the Universe was way more hostile, and only recently things have cooled down to make complex life possible. Vielleicht war das Universum in der Vergangenheit viel lebensfeindlicher, und erst in jüngster Zeit haben sich die Dinge abgekühlt, so dass komplexes Leben möglich wurde. Talvez no passado, o Universo fosse muito mais hostil, e só recentemente as coisas esfriaram para tornar a vida complexa possível. Возможно, в прошлом Вселенная была более враждебной, и только недавно все остыло, чтобы сделать возможной сложную жизнь. 也许在过去，宇宙更加敌对，直到最近事情才冷却下来，使复杂的生命成为可能。

This would also mean that we may be unique, or at least one of the first, if not the first civilization in the entire Universe. 这也意味着我们可能是独一无二的，或者至少是第一个，如果不是整个宇宙中的第一个文明。

Two: There are Great Filters and they are ahead of us. Dos: Hay Grandes Filtros y van por delante de nosotros. Dois: Existem Grandes Filtros e eles estão à nossa frente. Второй: есть отличные фильтры, и они впереди нас. 二：有很棒的过滤器，它们在我们前面。

This one, would be really really bad. 这一个，真的很糟糕。

Maybe life on our level exists everywhere in the Universe but it gets destroyed when it reaches a certain point, a point that lies ahead of us. Tal vez la vida a nuestro nivel exista en todas partes del Universo, pero se destruye cuando llega a cierto punto, un punto que está por delante de nosotros. Talvez a vida no nosso nível exista em todo o Universo, mas é destruída quando chega a um certo ponto, um ponto que está à nossa frente. Возможно, жизнь на нашем уровне существует повсюду во Вселенной, но она разрушается, когда достигает определенной точки, точки, которая находится впереди нас. 也许我们这个层次的生命存在于宇宙中的任何地方，但是当它到达某个点时，它就会被摧毁，这个点就在我们面前。

For example, awesome future technology exists, but when activated, it destroys the planet. Par exemple, une technologie future géniale existe, mais lorsqu'elle est activée, elle détruit la planète. Por exemplo, existe uma incrível tecnologia futura, mas quando ativada, destrói o planeta. 例如，存在令人敬畏的未来技术，但一旦被激活，它就会摧毁地球。

The last words of every advanced civilization would be: 每一个先进文明的遗言都是：

"This new device will solve all of our problems, once I push this button!" "Ce nouvel appareil résoudra tous nos problèmes, une fois que j'aurai appuyé sur ce bouton ! “这个新设备将解决我们所有的问题，只要我按下这个按钮！”

If this is true, then we are closer to the end then the beginning of human existence. Wenn das stimmt, dann sind wir näher am Ende als am Anfang der menschlichen Existenz. Se isso for verdade, então estamos mais perto do fim do que do começo da existência humana.

Or, maybe there is an ancient type three civilization, that monitors the universe, Ou, talvez haja uma antiga civilização tipo três, que monitora o universo, Или, может быть, существует древняя цивилизация третьего типа, которая следит за вселенной,

and once a civilization is advanced enough, it gets eliminated, in an instant. Und sobald eine Zivilisation weit genug fortgeschritten ist, wird sie im Handumdrehen eliminiert. et une fois qu'une civilisation est suffisamment avancée, elle est éliminée en un instant. e uma vez que uma civilização é avançada o suficiente, ela é eliminada, em um instante. и как только цивилизация становится достаточно развитой, она мгновенно уничтожается. 一旦一个文明足够先进，它就会在瞬间被淘汰。

Maybe there is something out there, that it would be better not to discover. Il existe peut-être quelque chose qu'il vaut mieux ne pas découvrir. 也许那里有一些东西，最好不要发现。

There is no way for us to know. Nous n'avons aucun moyen de le savoir.

One final thought: maybe we are alone. 最后一个想法：也许我们是孤独的。

Right now, we have no evidence that there's any life besides us. No momento, não temos evidências de que haja vida além de nós. 目前，我们没有证据表明除了我们之外还有其他生命。

Nothing. The Universe appears to be empty and dead.

No ones sending us messages, no one answering our calls.

We may be completely alone, trapped on a tiny moist mud ball in an eternal Universe. Podemos estar completamente sozinhos, presos em uma pequena bola de lama úmida em um Universo eterno. Мы можем быть совершенно одни, пойманные на крошечный влажный комочек грязи в вечной Вселенной. 我们可能完全孤独，被困在永恒宇宙中一个微小的潮湿泥球中。

Does that thought scare you? If it does, you are having the correct emotional reaction. Erschreckt Sie dieser Gedanke? Wenn ja, dann haben Sie die richtige emotionale Reaktion. ¿Le asusta ese pensamiento? Si es así, tu reacción emocional es la correcta. Эта мысль вас пугает? Если это так, у вас правильная эмоциональная реакция.

If we let life on this planet die, perhaps there would be no life left in the Universe. Life would be gone, maybe forever. Si dejáramos morir la vida en este planeta, quizá no quedaría vida en el Universo. La vida desaparecería, quizá para siempre. Если мы позволим жизни на этой планете умереть, возможно, во Вселенной не останется жизни. Жизнь ушла бы, может быть, навсегда.

If this is the case, we just have to venture to the stars and become the first Type Three civilization, Wenn das der Fall ist, müssen wir nur zu den Sternen aufbrechen und die erste Zivilisation vom Typ Drei werden, Se for esse o caso, temos apenas que nos aventurar nas estrelas e nos tornar a primeira civilização do Tipo Três, 如果是这样，我们只需要冒险去星际，成为第一个三类文明，

To keep the delicate flame of life existing, and to spread it until the universe breathes its final breath, Um die zarte Flamme des Lebens am Leben zu erhalten und sie zu verbreiten, bis das Universum seinen letzten Atemzug getan hat, Maintenir la délicate flamme de la vie et la répandre jusqu'à ce que l'univers rende son dernier souffle, Para manter a delicada chama da vida existindo e espalhá-la até que o universo dê seu último suspiro, Чтобы тонкое пламя жизни сохранялось и распространялось до тех пор, пока вселенная не испустит свой последний вздох, 为了保持生命的微妙火焰存在，并将其传播到宇宙呼吸最后一口气，

and vanishes into oblivion. e desaparece no esquecimento. 并消失在遗忘之中。

The universe is too beautiful not to be experienced by someone. O universo é lindo demais para não ser experimentado por alguém. Вселенная слишком прекрасна, чтобы никто не мог ее испытать. 宇宙太美了，没有人可以体验。

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