摘要：Because the James Webb Space Telescope is a telescope large enough to be able to catch light from planets like ours, as small as o

We live in an incredible time of exploration, on the verge of finding out whether we are alone in the cosmos or not.

我们生活在一个令人难以置信的探索时代，即将发现我们在宇宙中是否孤独。

This is one of the biggest questions humankind has ever asked.

这是人类迄今为止提出的最大问题之一。

And now, for the first time, we have a tool that could find out.

现在，我们第一次有了可以找出答案的工具。

Because the James Webb Space Telescope is a telescope large enough to be able to catch light from planets like ours, as small as ours, but circling other stars light-years away.

因为詹姆斯韦伯太空望远镜足够大， 能够捕捉到像我们的行星一样的行星发出的光，这些行星和我们的行星一样小， 但却围绕着数光年外的其他恒星运行。

Because this search is a search over vast cosmic distances, even light needs years to travel these trillions of miles between stars.

由于这次搜索是在广阔的宇宙距离上进行的，即使是光也需要数年的时间才能在恒星之间行进数万亿英里。

So when you look up at the sky at night, you look back in time.

因此，当你仰望夜空时，你会回顾过去。

Let's imagine you were on a planet circling our neighboring star, about four light-years away.

假设你在一颗围绕我们邻近恒星运行的行星上，距离我们约四光年。

Then you would see the Earth tonight, like it was four years ago.

那么你今晚就会看到地球，就像四年前一样。

On a planet 70 million light-years away, you could still see the dinosaurs roam here.

在距离我们7000万光年的星球上，你仍然可以看到恐龙在这里漫步。

And it also means that out in the sky, there is a star whose light arrives tonight, that was sent out when you were born.

这也意味着，今晚天空中有一颗星星发出的光芒，正是在你出生时发出的。

Your personal connection to the cosmos.

您与宇宙的个人联系。

So these distances are vast, but astronomers, throughout time, have managed to unravel and reveal mysteries of the cosmos, because light and matter interact.

这些距离是巨大的，但天文学家始终能够解开并揭示宇宙的奥秘，因为光和物质相互作用。

So light carries energy, and if it hits a molecule with just the right energy, that molecule will start to swing and rotate.

因此， 光携带能量， 如果它以适当的能量撞击分子，该分子就会开始摆动和旋转。

So it's really the missing light, the light that doesn't make it to my telescope, that tells me which molecules the light encountered before it got to me.

因此， 实际上是缺失的光， 即未到达望远镜的光，告诉我光到达我这里之前遇到了哪些分子。

It's a little bit like a passport stamp that tells you where a traveler was before arriving here.

它有点像护照上的印章，告诉你旅行者在抵达这里之前在哪里。

So when you look at this incredible image of the Pillars of Creation taken by the James Webb Space Telescope, it is gorgeous.

所以， 当你看到詹姆斯韦伯太空望远镜拍摄的这张令人难以置信的创生之柱图像时，你会觉得它非常美丽。

But if you analyze the light, you realize that we are watching a stellar nursery, where we see stars emerge and ignite.

但如果你分析光，你就会意识到我们正在观察一个恒星的摇篮，在那里我们看到恒星的出现和点燃。

And when you look at stars in our night sky, you reveal another astonishing truth -- that you and me, all of us, are made of ancient stardust.

当你仰望夜空中的星星时，你会发现另一个惊人的事实——你和我，我们所有人都是由古老的星尘构成的。

Because it took the heat in the core of a star and the violent explosion at the end of its lifetime to make the atoms that made you and me.

因为需要恒星核心的热量和其生命末期的剧烈爆炸才能形成构成你和我自身的原子。

So on a fundamental level, we are connected to each other and to the cosmos around us.

因此，从根本上来说，我们彼此相连，并与我们周围的宇宙相连。

And now, for the first time, we get to search for other organisms somewhere else that might be made of ancient stardust, too.

现在，我们第一次可以在其他地方寻找可能也是由古老星尘构成的其他生物。

But when you try to find life in the universe, it is incredibly hard, because planets are so much smaller, and they are close to their bright and big stars.

但是当你尝试在宇宙中寻找生命时，这是非常困难的， 因为行星太小了，而且它们靠近明亮而巨大的恒星。

And we don't only want to find planets like ours, we want to look in their air and on their surface for signs of life.

我们不仅想找到像我们这样的行星，我们还想在它们的大气层和表面寻找生命的迹象。

So what we do is we wait until the planet crosses our line of sight to its star, and the light from its star hits, smashes into the atmosphere of the planet before it gets to my telescope.

因此，我们要做的就是等待行星穿过我们的视线到达其恒星，然后其恒星发出的光撞击行星大气层，然后才到达我的望远镜。

So I can look for these passport stamps to figure out what's in the air of planets very far away, and the light fingerprint.

所以我可以寻找这些护照印章来弄清楚遥远行星的空气中有什么，以及光指纹。

The best light fingerprint we have for life on the Earth is the combination of oxygen and methane for carbon-based life, with a water solvent, on a planet in the temperate zone around its star.

我们所掌握的地球生命的最佳光指纹是，在其恒星周围温带地区的行星上，碳基生命的氧气和甲烷与水溶剂的结合。

But I was really curious: How long could this light fingerprint tell you that there's life on our planet?

但我真的很好奇：这种光指纹多久能告诉你我们的星球上存在生命？

And so I figured out that, for about two billion years, the biosphere has painted signs of life into our atmosphere.

因此我发现， 大约二十亿年来，生物圈已经在我们的大气层中留下了生命的迹象。

So for half of Earth's existence, you could tell that there is life on our planet.

因此，在地球存在的一半时间里，你可以看出我们的星球上存在生命。

And if life does this somewhere else too, for the first time, we have now a chance to spot it.

如果其他地方的生命也存在这样的情况，我们现在就有机会第一次发现它。

And so searching for life in the universe actually made me see our planet completely differently.

因此，在宇宙中寻找生命实际上让我对我们的星球有了完全不同的看法。

Here, for example, you see biota that colors these amazing hot sulphur springs in New Zealand this gorgeous orange color, and it lets you start to think about how different these other planets could be.

比如， 在这里， 你可以看到生物群落将新西兰令人惊叹的硫磺温泉染成了华丽的橙色，这让你开始思考其他星球可能有多么不同。

There could be could be planets completely covered in oceans, with waves that never break on a shore.

可能存在完全被海洋覆盖的行星，海浪永远不会冲击海岸。

Or planets half in eternal sunlight and half in perpetual night.

或者行星一半处于永恒的阳光下，一半处于永恒的黑夜中。

Or planets that are covered with a purple landscape.

或者是被紫色景观覆盖的行星。

Because purple bacteria is very sturdy, it can thrive under red sunlight.

由于紫色细菌非常顽强，它能在红色阳光下茁壮成长。

So eight out of ten stars out there are actually small red stars.

因此，实际上十颗星星中有八颗都是小红星。

So purple might be the new green, when searching for life in the cosmos.

因此，在寻找宇宙生命时，紫色可能成为新的绿色。

But we know that one out of five sun-like stars has a planet that could potentially be like ours.

但我们知道，五分之一的类太阳恒星中，有一颗可能拥有与我们相似的行星。

So with 200 billion stars in our Milky Way alone, that means we have billions and billions of possibilities.

因此，仅我们的银河系就有 2000 亿颗恒星，这意味着我们拥有数十亿种可能性。

I founded the Carl Sagan Institute at Cornell to bring thinkers and creative minds from many different fields and backgrounds and ways of life together to create the toolkit to find life in the cosmos.

我在康奈尔大学创立了卡尔萨根研究所，旨在将来自不同领域、背景和生活方式的思想家和富有创造力的人才聚集在一起，创造出寻找宇宙生命的工具包。

And so we created a spectral database, a light-fingerprint database for habitable worlds.

因此我们创建了一个光谱数据库，一个适合居住星球的光指纹数据库。

And in case you're wondering, actually, Jurassic worlds, where space dinosaurs might roam somewhere else, are actually easier to find than a modern Earth, because there was more oxygen when the dinosaurs lived here.

如果你想知道的话，实际上，侏罗纪世界（太空恐龙可能在其他地方漫游）实际上比现代地球更容易找到，因为恐龙生活在这里时氧气更多。

I'm not saying there are space dinosaurs, but I'm just saying if you ever wanted there to be, I'm giving you options.

我并不是说有太空恐龙，我只是说如果你希望有太空恐龙，我会给你提供选择。

(Laughter) But when you search, then one of the questions that came was also if there's life in the cosmos.

（笑声）但是当你探索的时候，随之而来的一个问题是，宇宙中是否存在生命。

Of course, I don't know that yet.

当然，我还不知道。

But if there's life in the cosmos, could somebody be looking at us with just the same technology we have?

但是如果宇宙中存在生命，有人能用我们所拥有的技术来观察我们吗？

And there's a space in the sky, a strip where you have just the right vantage point to see the Earth go in front of the Sun.

天空中有一片空间，一条狭长地带，从那里你可以看到地球在太阳前面运行的景象。

And it encapsulates about 1,000 stars within 300 light-years, what's really our cosmic background.

它涵盖了 300 光年内的大约 1,000 颗恒星，这才是我们真正的宇宙背景。

And so the question is, where could we be the aliens?

那么问题来了，我们可能是外星人吗？

Is there life in the cosmos?

宇宙中存在生命吗？

I don't know.

我不知道。

We don't know yet, but I really want to find out, because the cosmos is 13.8 billion years old, but we all get to live in the most exciting time, where the search for life on other planets went from impossible to possible.

我们还不知道， 但我真的想找到答案，因为宇宙已有 138 亿年的历史，但我们都生活在最激动人心的时代，寻找其他星球上的生命从不可能变成了可能。

And it's at the edge of technical capability, but we're already designing larger telescopes that could catch more light of these planets to find out if there's life out there calling another planet home.

这还处于技术能力的前沿，但我们已经在设计更大的望远镜， 可以捕捉到更多行星的光线， 以查明外星上是否有生命。

From a tiny town in Austria, when I looked up at the stars and wondered if they could be suns to their planets, to now sitting in Carl Sagan's old office at Cornell, the journey has been challenging, inspiring and full of wonder, because those thousands of new stars, new suns [in] the sky, hold a breathtaking promise that our adventure of exploration has just begun.

我从奥地利的一个小镇仰望星空， 思考它们是否能成为行星的太阳，到现在坐在康奈尔大学卡尔萨根的旧办公室里，这段旅程充满挑战、鼓舞人心和奇迹，因为天空中数以千计的新星星、新太阳，承载着令人惊叹的希望， 预示着我们的探索之旅才刚刚开始。

So go out at night and find your favorite star, and allow yourself to wonder, what if we're not alone?

因此， 晚上出去寻找你最喜欢的明星，并允许自己思考， 如果我们并不孤单会怎样？

Thank you.

谢谢。

来源：英语东