TED演讲:引力与人体(2)

（单词翻译）

　　You know, all life developed here on Earth with gravity being present, 你知道，地球上的生物在重力环境下生存，

　　so life evolved under the influence of gravity, and then we grow up with gravity being present, 你知道，地球上的生物在重力环境下生存，

　　so we learn how to walk and catch a ball and ice skate or whatever, all with gravity being present. 所以我们学会如何走路、如何接球，以及溜冰等等，这些都与重力的存在息息相关。

　　And what if you were to grow up without gravity? 那么如果你不是在重力环境下长大的呢？

　　What about the systems that depend on gravity, 那些依赖重力的身体系统，

　　like your muscles or your balance system or the heart and blood vessels¹? 比如肌肉、平衡系统或者心血管系统会怎么样呢？

　　Would they develop normally, or would they be different in some way? 它们会正常发展吗？或者会有所不同吗？

　　One reason why you might think that it would go down a different pathway is from an experiment 你可能觉得事情会朝另一个方向发展，

　　that was done some time ago by two neuroscientists called Hubel and Wiesel. 不久以前，两个叫做休博尔和维瑟尔的神经学家做的实验替你给出了理由。

　　And what they did is they had a kitten, and they put a patch over the eye of the kitten. 他们有一只小猫，他们给小猫的一只眼睛戴上眼罩。

　　And then the kitten grew up to be a cat, and they removed the patch. 小猫长大后，他们为其取下眼罩。

　　And so, the question is, can the cat see out of that eye? 那么，问题是它能用那只眼睛看到东西么？

　　Now, there's nothing wrong with the eye, right? 现在，眼睛本身没有任何问题，对吧？

　　But it just hasn't seen anything, there hasn't been any light coming in. 但是猫看不到任何东西，这只眼睛感知不见任何光线。

　　And the answer is that the cat can't see out of that eye 答案是，猫不能从那只眼睛看到任何东西，

　　because what happens is that the brain goes down a different pathway when it develops 因为它在大脑发育上出了岔子，

　　and the connections that would ordinarily develop to that eye don't develop. 本应该发育的那只眼睛的连接没有发育。

　　And that can't be undone², that's a permanent change. 而且这是不可逆的，是一个永久的改变。

　　So, the brain of that cat is fundamentally different from the brain of a cat that grew up seeing out of that eye. 所以，这只猫的大脑与通过那只眼睛视物长大的猫的大脑根本不一样。

　　That cat grew up with a different brain, in essence³. 本质上，那只猫长出了一颗不一样的大脑。

　　So, then you wonder, well, what about gravity? 然后，你会奇怪，好吧，那么重力怎么说？

　　What if you don't have the forces that gravity produces? 失去重力的影响会怎么样？

　　Is your balance organ going to develop in the same way, or will it be different? 你的平衡系统将会以同样的方式来发育吗？抑或是按另一种方式发育？

　　If somebody grew up in space, could they come back to Earth and function, or would they really be a different person? 如果有人在太空中长大，他们能回到地球上并且功能健全吗？又或者他们实际上会变成一个不一样的人？