(单词翻译:单击)
Living on a planet has a lot of advantages,
生活在一个星球上有很多好处,
like strong gravity to keep us from flying off into space,
比如，强大的引力能阻止我们飞向太空，
and the magnetic field and an atmosphere to protect us from damaging solar radiation.
磁场和大气层保护我们免受太阳辐射的伤害。
But what if an advanced civilization ran out of room to grow on their home planet?
但是，万一一个先进的文明把他们星球的空间用光了怎么办？
What if they ran out of energy and resources to keep themselves going?
万一他们把用于发展的能源用光了怎么办？
Well, their best bet might be to build settlements in space,
那么，他们最好的选择可能是在太空建造定居点，
so they could capture more of their star's energy, not another planet, though.
这样，他们就可以捕捉到更多的恒星能量，而不是另一颗行星的。
I mean, just sort of floating around out there.
我的意思是，定居点在外面漂浮。
There's a whole field of science that deals with how that might work. It's called astro-engineering.
有一整个科学领域都在研究它是如何运作的，这一领域叫做天体工程。
And it's full of really cool, though still very hypothetical ideas.
它充满很酷的想法，尽管有很多都是假设。
One of the most famous astro-engineering concepts is known as a Dyson Sphere.
其中最著名的天体工程概念被誉为戴森球体。
An object that captures more of the star's light, and converts it into useful energy.
戴森球体能捕捉更多的恒星能量，并把它转化成有用的能量。
It's named after Freeman Dyson, an astrophysicist who published a paper on this concept back in 1960.
它是以天体物理学家弗里曼·戴森的名字命名的，在他1960年发表的论文里被提及。
He pointed out that only a tiny amount of the sun's light output hits Earth.
戴森指出只有少量的太阳光照射到地球上。
Since the rest is emitted in other directions.
因为其余的都散发到了其他方向。
And he proposed that other civilizations might have had to build some kind of structure to harness more energy from their local star.
他提出，其他的文明可能已经建立了某种建筑来更多地利用本土恒星的能量。
And could now be using so much energy, that we'd be able to detect their waste heat from here, on Earth.
现在，既然他们使用了如此多的能量，我们就能从地球上检测到他们的废热。
But, he didn't go into detail about how that might work.
但他没有细讲运作过程。
Since then, astro-engineers have been developing the concept.
自那以后，太空工程师一直在发展这个概念。
And one of the more well-known possibilities, first showed up in the 1930's science fiction novel: Star Maker.
有一个更广为人知的可能性，最早出现在1930年的科幻小说《造星人》中。
And has been featured in lots of stories since then.
从那时起，有很多这类故事出现。
What if they had a huge spherical shell surrounding their sun, like some kind of cosmic egg?
如果他们在本土恒星周围有个像宇宙卵一样的巨大球形外壳会怎样？
If their home-star was similar to ours and they built it with a radius of one astronomical unit or AU, which is the distance from the Earth to the sun,
如果他们的本土恒星和我们的太阳类似，他们建造的球体半径是一个天文单位（AU，即地球到太阳的距离），
then, every point in that sphere would get the same amount of radiation as here on the Earth.
那么球面上的每一点都会得到与地球一样多的辐射。
Add up all the points on the shell and that's a lot of solar power, which would be great for a civilization that was low on energy.
把球面上所有的点加起来，就会得到很多的太阳能，这对于一个低能量的文明来说是很好的。
And there's a bonus!
这是红利！
If they fixed up the surface of the shell with a nice atmosphere and a comfortable habitat,
如果他们把球面固定在一个美好舒适的环境中，
it would also provide a much larger area to spread out into.
它还将有一个更大的扩展区域。
But, of course there are lots of obvious limitations.
当然，它有很多明显的限制。
A structure so huge would probably need more building material that exists in our entire solar system.
一个如此浩大的建筑可能需要更多来自整个太阳系的建筑材料，
Though, another solar system might have more to work with.
不过，另一个太阳系可能有更多的工作要做。
But then the sphere, constantly being exposed to sunlight, would be too hot for life, electronics, and maybe even the structure itself.
然后就是大气，长期暴露在阳光下，对生命、电子甚至建筑本身来说都太热了。
They could try building a bigger one, so that the shell would be farther from the sun and wouldn't get as hot.
他们试着建造一个更大的建筑，这样的话，球面离太阳较远，就不会那么热了。
But, then they'd need even more stuff to build it.
但这样就需要更多的建筑材料。
Either way, they'd have some gravity problems.
不管怎样，他们都有一些重力问题。
Standing on the outside of the sphere, they would only feel the tiny pull of their home star.
站在球体外面，他们只能感觉到本土恒星的微弱拉力。
And if they were on the inside of that shell, they'd feel the same pull and start floating toward their sun.
如果他们在球体里面，他们会感受到同等的拉力并朝着本土恒星漂移。
You could try to get the sphere spinning to simulate gravity, but it would take a lot of energy.
你可以试着让球体旋转来模拟重力，但这需要很多能量。
And you'd still only get an Earth-like gravitational pull near the equator.
你只能在靠近赤道的地方得到类似地球的引力。
On top of everything else, on the inside of the sphere, the gravitiational attraction cancels out.
除此之外，在球体内部，重力抵消了。
So, it'd basically be free floating around their sun.
所以，它基本上可以自由漂浮在太阳周围。
Any minor nudge, like from an asteroid hit, would set the thing drifting and eventually, it would crash into the star.
任何轻推，就像小行星撞击地球一样，都会使物体漂移，最终撞到恒星上。
So, what if they built a swarm of smaller structures and spread them out around the sun, instead of one huge, rigid shell?
那么，万一他们没有建造巨大坚硬的外壳，而是建造了一群更小的建筑，并将它们散布在太阳周围呢?
That might be a little more doable.
这可能有点儿可行。
It's the same thing concept as the Dyson Sphere,
这和戴森球体的概念相同，
because they're spreading out around the sun to gather more of its energy.
因为他们都是散布在太阳周围，以收集更多的能量。
It's just... not a sphere.
只不过…它不是一个球体。
For example, they could try using solar collectors devices that capture the sun's energy.
比如，它们可以尝试使用太阳能收集器来收集太阳能。
Balanced on solar sails, thin mirrors designed to be pushed around by the pressure of the sun's radiation.
薄膜镜被太阳辐射压推动来平衡太阳帆。
Then, they could stick them right where the inward pull of their sun's gravity would be just as strong as the outward push of its radiation.
这样，它们在相同强度的内部太阳引力和外部辐射压力作用下能坚持住。
They'd be like space power plants, transferring the extra energy they collected to smaller, more self-contained space habitats.
它们就像太空发电厂，把它们收集的多余能量用于更小更独立的太空栖息地使用。
But with all these hurdles, humans are no where near being able to build a Dyson Sphere or anything like it.
但有这些障碍，人们就不能建造戴森球体或任何此类的东西。
But, we are looking for signs that other civilizations might have.
但是我们正在寻找其他文明可能存在的迹象，
In the process of gathering and using all that energy, they'd produce lots of extra heat, mostly in the infrared part of the spectrum.
在聚集和使用那种能量的过程中，它们会产生很多废热，这些废热大部分在光谱的红外部分。
That's why astronomers are scanning other galaxies for infrared spikes that seem like they shouldn't be there.
这就是为什么天文学家正在寻找其他星系中不应存在的红外峰值。
So, these huge astro-engineering projects might have to stay theoretical for now,
因此，这些大型的天体工程项目现在可能得停留在理论上,
but trying to figure out how they might work, gives us new ideas about how to look for other life that could be out there in the universe.
但是试着弄清楚他们的工作原理，使我们有了关于如何寻找宇宙中其他生命的新想法。
Thanks for watching this episode of SciShowSpace,
感谢您收看本期的太空科学秀，
and especially to our Patrons on Patreon who help make this show possible.
特别感谢Patreon对本节目的大力支持，
If you wanna help support this content, just go to Patreon.com/SciShow.
如果你想资助这类内容，请登录Patreon.com/SciShow。
And don't forget to go to YouTube.com/SciShowSpace and subscribe.
也不要忘了登录YouTube.com/SciShowSpace 点击订阅哦！
