无人知晓答案的问题

Questions No One Knows the Answers to
无人知晓答案的问题。

On a typical day at school, endless hours are spent learning the answers to questions, but right now, we’ll do the opposite.
在学校的日常生活中，我们花费无尽的时间去学习问题的答案，但此刻，我们将反其道而行之。

We’re going to focus on questions where you can’t learn the answers because they’re unknown.
我们将专注于那些你无法找到答案的问题，因为它们是未知的。

I used to puzzle about a lot of things as a boy, for example What would it feel like to be a dog?
我小时候常常对很多事情感到困惑，比如，成为一只狗会是一种什么感觉？

Do fish feel pain?
鱼会感到疼痛吗？

How about insects?
那么昆虫呢？它们会感到疼痛吗？

Was the Big Bang just an accident?
大爆炸仅仅是一个偶然事件吗？

And is there a God?
那么，真的有上帝存在吗？

And if so, how are we so sure that it’s a He and not a She?
如果有上帝，我们是如何确信它是男性而不是女性呢？

Why do so many innocent people and animals suffer terrible things?
为什么那么多无辜的人和动物要遭受如此可怕的事情？

Is there really a plan for my life?
我的生活真的有一个既定的计划吗？

Is the future yet to be written, or is it already written and we just can’t see it?
未来是尚未书写的，还是已经写好而我们只是无法看到它？

But then, do I have free will?
但是，我拥有自由意志吗？

I mean, who am I anyway?
我的意思是，不管怎样，我到底是谁？

Am I just a biological machine?
难道我只是一台生物机器吗？

But then, why am I conscious?
但是，为什么我有意识呢？

What is consciousness?
意识究竟是什么？

Will robots become conscious one day?
机器人有一天会变得有意识吗？

I mean, I kind of assumed that some day I would be told the answers to all these questions.
我的意思是，我有点想当然地认为总有一天我会被告知所有这些问题的答案。

Someone must know, right?
总有人知道答案，对吧？

Guess what? No one knows.
猜猜看？没有人知道。

Most of those questions puzzle me more now than ever.
现在，这些问题比以往任何时候都更让我感到困惑。

But diving into them is exciting because it takes you to the edge of knowledge, and you never know what you’ll find there.
但深入探究这些问题非常激动人心，因为这会将你带到知识的边缘，而你永远不知道会在那里发现什么。

So, two questions that no one on Earth knows the answer to.
那么，有两个问题，地球上的任何人都不知道答案。

How many universes are there?
到底存在多少个宇宙？

Sometimes when I’m on a long plane flight, I gaze out at all those mountains and deserts and try to get my head around how vast our Earth is.
有时，当我在长途飞行中，我会凝视着那些山脉和沙漠，试图理解我们地球的辽阔。

And then I remember that there’s an object we see every day that would literally fit one million Earths inside it the Sun.
然后我会想起，我们每天都能看到的一个天体，它的内部实际上可以容纳一百万个地球——那就是太阳。

It seems impossibly big.
它似乎大得难以想象。

But in the great scheme of things, it’s a pinprick, one of about billion stars in the Milky Way galaxy, which you can see on a clear night as a pale white mist stretched across the sky.
但在宏大的宇宙图景中，太阳不过是一个微不足道的点，它是银河系中大约一千亿颗恒星之一，在晴朗的夜晚，你可以看到它像一片淡淡的白色薄雾横跨在天空中。

And it gets worse.
而且情况还远不止如此。

There are maybe billion galaxies detectable by our telescopes.
通过我们的望远镜可能探测到的星系数量也许有上亿个。

So if each star was the size of a single grain of sand, just the Milky Way has enough stars to fill a -foot by -foot stretch of beach three feet deep with sand.
所以，如果每颗恒星的大小相当于一粒沙子，仅银河系中的恒星就足以填满一个长宽各英尺、深三英尺的沙滩。

And the entire Earth doesn’t have enough beaches to represent the stars in the overall universe.
而且整个地球上的沙滩加起来也不足以代表整个宇宙中的恒星数量。

Such a beach would continue for literally hundreds of millions of miles.
这样的沙滩实际上会延伸数亿英里之长。

Holy Stephen Hawking, that is a lot of stars.
天哪，这真是难以置信的恒星数量，简直令人敬畏如斯蒂芬·霍金。

But he and other physicist snow believe in a reality that is unimaginably bigger still.
但是他和其他物理学家现在相信，现实世界比我们所能想象的还要庞大得多。

I mean, first of all, the billion galaxies within range of our telescopes are probably a minuscule fraction of the total.
我的意思是，首先，我们望远镜所能观测到的数十亿个星系，可能只是总数中微不足道的一小部分。

Space itself is expanding at an accelerating pace.
宇宙空间本身正在以加速的速度膨胀。

The vast majority of the galaxies are separating from us so fast that light from them may never reach us.
绝大多数星系正以如此快的速度远离我们，以至于它们的光可能永远无法到达我们这里。

Still, our physical reality here on Earth is intimately connected to those distant, invisible galaxies.
然而，我们地球上物理现实与那些遥远、不可见的星系紧密相连。

We can think of them as part of our universe.
我们可以将它们视为我们宇宙的一部分。

They make up a single, giant edifice obeying the same physical law sand all made from the same types of atoms, electrons, protons, quarks, neutrinos, that make up you and me.
它们构成了一个单一的、巨大的结构，遵循着相同的物理定律，而且都是由构成你我的相同类型的原子、电子、质子、夸克和中微子等组成。

However, recent theories in physics, including one called string theory, are now telling us there could be countless other universes built on different types of particles, with different properties, obeying different laws.
然而，物理学中的最新理论，包括所谓的弦理论，现在告诉我们可能存在无数其他由不同类型的粒子构建的宇宙，它们具有不同的属性，遵循不同的定律。

Most of these universes could never support life, and might flash in and out of existence in a nanosecond.
这些宇宙中的大多数可能永远无法支持生命，它们可能在纳秒之间闪现然后消失。

But nonetheless, combined, they make up a vast multiverse of possible universes in up to dimensions, featuring wonders beyond our wildest imagination.
但尽管如此，它们结合起来构成了一个广阔的多宇宙，其中可能存在高达维度不同的宇宙，展现了超乎我们最狂野想象之外的奇迹。

The leading version of string theory predicts a multiverse made up of to the universes.
弦理论的主要版本预测了一个由多达宇宙组成的多元宇宙。

That’s a one followed by zeros, a number so vast that if every atom in our observable universe had its own universe, and all of the atoms in all those universes each had their own universe, and you repeated that for two more cycles, you’d still be at a tiny fraction of the total, namely, one trillion trillion trilliontrillion trillion trillion trilliontrillion trillion trillion trilliontrillion trillion trillion trillionth.
这是一个1后面跟着个0的数字，如此庞大，以至于如果我们的可观测宇宙中的每一个原子都有自己的宇宙，并且所有那些宇宙中的每一个原子又都有自己的宇宙，如果你将这个过程再重复两次，你得到的总数仍然只是总量的一个小小部分，具体来说，是千万亿分之一的千万亿分之一的千万亿分之一的千万亿分之一的千万亿分之一的千万亿分之一的千万亿分之一的千万亿分之一。

But even that number is minuscule compared to another number infinity.
但即使这个数字与另一个数字——无穷大相比，也是微不足道的。

Some physicists think the space-time continuum is literally infinite and that it contains an infinite number of so-called pocket universes with varying properties.
一些物理学家认为，时空连续体实际上是无限的，并且它包含无限多个所谓的口袋宇宙，这些宇宙具有不同的属性。

How’s your brain doing?
你的大脑感觉如何？是不是被这些概念弄得有些晕头转向？

Quantum theory adds a whole new wrinkle.
量子理论又增添了全新的复杂性。

I mean, the theory’s been proven true beyond all doubt, but interpreting it is baffling, and some physicists think you can only un-baffle it if you imagine that huge numbers of parallel universes are being spawned every moment, and many of these universes would actually be very like the world we’re in, would include multiple copies of you.
我的意思是，这个理论已经被证明是毫无疑问的正确，但解释它却令人困惑，一些物理学家认为，只有想象在每一刻都在产生大量的平行宇宙，你才能解开这个困惑。许多这样的宇宙实际上会非常像我们所在的这个世界，甚至会包括你的多个副本。

In one such universe, you’d graduate with honors and marry the person of your dreams, and in another, not so much.
在这样一个宇宙中，你可能会以优异的成绩毕业，并与你梦想中的伴侣结婚；而在另一个宇宙中，情况可能就大不相同了。

Well, there are still some scientists who would say, hogwash.
嗯，仍有一些科学家会说，这些都是胡说八道。

The only meaningful answer to the question of how many universes there are is one.
关于宇宙数量的问题，唯一有意义的答案就是只有一个。

Only one universe.
只有一个宇宙。

And a few philosophers and mystics might argue that even our own universe is an illusion.
一些哲学家和神秘主义者可能会争论说，甚至我们自己的宇宙都是一个幻象。

So, as you can see, right now there is no agreement on this question, not even close.
所以，正如你所看到的，关于这个问题，目前还没有达成任何共识，甚至相差甚远。

All we know is the answer is somewhere between zero and infinity.
我们所知道的是，答案在零和无穷大之间。

Well, I guess we know one other thing.
嗯，我想我们还知道另一件事。

This is a pretty cool time to be studying physics.
这是一个研究物理学非常酷的时代。

We just might be undergoing the biggest paradigm shift in knowledge that humanity has ever seen.
我们可能正在经历人类历史上知识领域最大的范式转变。

Why can’t we see evidence of alien life?
为什么我们看不到外星生命的证据？

Somewhere out there in that vast universe there must surely be countless other planets teeming with life.
在那广阔的宇宙中的某个地方，肯定有无数其他的行星充满了生命。

But why don’t we see any evidence of it?
但为什么我们看不到任何外星生命的证据呢？

Well, this is the famous question asked by Enrico Fermi in Where is everybody?
嗯，这就是恩里科·费米提出的著名问题：“大家都在哪儿呢？”

Conspiracy theorists claim that UFOs are visiting all the time and the reports are just being covered up, but honestly, they aren’t very convincing.
阴谋论者声称不明飞行物（UFOs）一直在访问地球，而这些报告只是被掩盖了，但老实说，这些说法并不怎么令人信服。

But that leaves a real riddle.
但这留下了一个真正的谜团。

In the past year, the Kepler space observatory has found hundreds of planets just around nearby stars.
在过去的几年里，开普勒太空望远镜已经在附近的恒星周围发现了数百颗行星。

And if you extrapolate that data, it looks like there could be half a trillion planets just in our own galaxy.
如果你对这些数据加以外推，看起来在我们的银河系中可能会有五百亿颗行星。

If any one in , has conditions that might support a form of life, that’s still million possible life-harboring planets right here in the Milky Way.
如果在这些行星中的任何一个，有支持某种生命形式的条件，那仍然意味着在我们的银河系中可能有上百万个可能存在生命的行星。

So here’s the riddle our Earth didn’t form until about nine billion years after the Big Bang.
所以这里就是谜团：我们的地球直到大爆炸之后大约90亿年才形成。

Countless other planets in our galaxy should have formed earlier, and given life a chance to get underway billions, or certainly many millions of years earlier than happened on Earth.
我们银河系中的无数其他行星应该更早形成，并且给生命以数十亿年，或者至少数百万年的时间来发展，比地球上生命出现的时间要早得多。

If just a few of them had spawned intelligent life and started creating technologies, those technologies would have had millions of years to grow in complexity and power.
如果其中只有少数几个行星孕育出了智能生命并开始创造技术，那么这些技术就会有数百万年的时间来增长其复杂性和能力。

On Earth, we’ve seen how dramatically technology can accelerate in just years.
在地球上，我们已经看到技术如何在短短几年内急剧加速发展。

In millions of years,an intelligent alien civilization could easily have spread out across the galaxy, perhaps creating giant energy-harvesting artifacts or fleets of colonizing spaceships or glorious works of art that fill the night sky.
在数百万年的时间里，一个智能外星文明可能已经轻易地遍布整个银河系，或许创造了巨大的能量收集器、殖民宇宙的舰队，或者充满夜空的辉煌艺术作品。

At the very least, you’d think they’d be revealing their presence, deliberately or otherwise, through electromagnetic signals of one kind or another.
至少，你会认为他们会在有意或无意间通过一种或多种电磁信号揭示他们的存在。

And yet we see no convincing evidence of any of it.
然而，我们看不到任何令人信服的证据。

Why?
为什么？

Well, there are numerous possible answers, some of them quite dark.
嗯，有许多可能的答案，其中一些相当阴暗。

Maybe a single, super intelligent civilization has indeed taken over the galaxy and has imposed strict radio silence because it’s paranoid of any potential competitors.
也许有一个超级智能文明确实已经控制了银河系，并且实施了严格的无线电静默，因为它对任何潜在的竞争者都感到偏执。

It’s just sitting there ready to obliterate anything that becomes a threat.
它就在那里，随时准备消灭任何成为威胁的东西。

Or maybe they’re not that intelligent, or perhaps the evolution of an intelligence capable of creating sophisticated technology is far rarer than we’ve assumed.
或者也许它们并没有那么智能，又或许能够创造出精密技术的智能生命的进化比我们假设的要罕见得多。

After all, it’s only happened once on Earth in four billion years.
毕竟，在地球四十亿年的历史中，这样的智能生命只出现过一次。

Maybe even that was incredibly lucky.
也许这本身就是难以置信的幸运。

Maybe we are the first such civilization in our galaxy.
也许我们是银河系中第一个这样的文明。

Or, perhaps civilization carries with it the seeds of its own destruction through the inability to control the technologies it creates.
或者，也许文明本身就携带了自我毁灭的种子，因为它无法控制自己创造的技术。

But there are numerous more hopeful answers.
但也有许多更加乐观的答案。

For a start, we’re not looking that hard, and we’re spending a pitiful amount of money on it.
首先，我们的搜寻工作并不那么尽力，我们在这一领域投入的资金少得可怜。

Only a tiny fraction of the stars in our galaxy have really been looked at closely for signs of interesting signals.
我们银河系中只有极小一部分恒星被仔细搜寻过是否有有趣的信号。

And perhaps we’re not looking the right way.
也许我们的搜寻方式并不正确。

Maybe as civilizations develop, they quickly discover communication technologies far more sophisticated and useful than electromagnetic waves.
也许随着文明的发展，它们很快就会发现比电磁波更复杂、更有用的通信技术。

Maybe all the action takes place inside the mysterious recently discovered dark matter, or dark energy, that appear to account for most of the universe’s mass.
也许所有活动都在最近发现的神秘的暗物质或暗能量中进行，这些物质和能量似乎构成了宇宙大部分的质量。

Or, maybe we’re looking at the wrong scale.
或者，也许我们的关注点规模不对。

Perhaps intelligent civilizations come to realize that life is ultimately just complex patterns of information interacting with each other in a beautiful way, and that that can happen more efficiently at a small scale.
也许智能文明最终会意识到，生命归根结底只是复杂的信息模式以美丽的方式相互作用，而这种相互作用在小尺度上可以更高效地进行。

So, just as on Earth, clunky stereo systems have shrunk to beautiful, tiny iPods, maybe intelligent life itself, in order to reduce its footprint on the environment, has turned itself microscopic.
所以，就像在地球上，笨重的立体声音响系统已经缩小成了美丽的小型iPods，也许智能生命本身为了减少对环境的影响，已经变得微不足道。

So the Solar System might be teeming with aliens, and we’re just not noticing them.
因此，太阳系可能充满了外星人，而我们只是没有注意到他们。

Maybe the very ideas in our heads are a form of alien life.
也许我们头脑中的想法本身就是一种外星生命的形态。

Well, okay, that’s a crazy thought.
好吧，这个想法确实有点疯狂。

The aliens made me say it.
是外星人让我这么说的。

But it is cool that ideas do seem to have a life all of their own and that they outlive their creators.
但有趣的是，想法似乎确实拥有自己的生命，并且它们比创造者本身更长久。

Maybe biological life is just a passing phase.
也许生物生命只是一个短暂的阶段。

Well, within the next years, we could start seeing real spectroscopic information from promising nearby planets that will reveal just how life-friendly they might be.
在未来几年内，我们可能会开始看到来自附近有前景行星的真实光谱信息，这将揭示它们对生命有多么友好。

And meanwhile, SETI, the Search for Extra terrestrial Intelligence, is now releasing its data to the public so that millions of citizen scientists, maybe including you, can bring the power of the crowd to join the search.
同时，搜寻外星智能生命（SETI）现在正在向公众发布其数据，以便数百万名公民科学家，也许包括您，可以利用众人的力量加入到搜寻工作中。

And here on Earth, amazing experiments are being done to try to create life from scratch, life that might be very different from the DNA forms we know.
在地球上，人们正在进行惊人的实验，试图从零开始创造生命，这种生命可能与我们所知的DNA形式大不相同。

All of this will help us understand whether the universe is teeming with life or whether, indeed, it’s just us.
所有这些都将帮助我们理解宇宙是否充满了生命，或者实际上只有我们存在。

Either answer, in its own way, is awe-inspiring, because even if we are alone, the fact that we think and dream and ask these questions might yet turn out to be one of the most important facts about the universe.
无论哪个答案，都以它自己的方式令人敬畏，因为即使我们独自存在，我们思考、梦想和提出这些问题的事实，可能最终会成为关于宇宙最重要的真相之一。

And I have one more piece of good news for you.
还有一条好消息要告诉您。

The quest for knowledge and understanding never gets dull.
对知识和理解的追求永远不会变得乏味。

It doesn’t. It’s actually the opposite.
确实不会。实际上恰恰相反。

The more you know, the more amazing the world seems.
你知道得越多，世界就显得越神奇。

And it’s the crazy possibilities, the unanswered questions, that pull us forward.
正是这些疯狂的可能性，这些未解答的问题，推动着我们不断前进。

So stay curious.
所以，保持好奇心。