第2集 【费曼访谈】想象的乐趣

[段 1]

It’s interesting that some people find science so easy and others find it kind of dull and difficult. Especially kids, you know, some of them just eat it up. And I don’t know why it is. It’s the same perhaps for all subjects. For instance, lots of people love music and I never could carry a tune. I lose a great deal of pleasure out of that. And I think people lose a lot of pleasure who find science dull. In the case of science, I think that one of the things that make it very difficult is it takes a lot of imagination. It’s very hard to imagine all the crazy things that things really are like. Nothing’s really as it seems. We’re used to get hot and cold and all that. Hot and cold is is the speeds that the atoms are jiggling. If they jiggle more, it corresponds to hotter, and colder is jiggling less. So if you have a bunch of atoms, a cup of coffee or something sitting on a table, and the atoms are jiggling a great deal in the coffee, and they bounce against the cup, and the cup then gets shaking, and the atoms in the cup shake, and they bounce against the saucer, and the heat heats the cup and heats everything else.

[译文 1]

有趣的是，有些人觉得科学轻而易举，而另一些人却觉得它枯燥乏味、晦涩难懂。尤其是孩子们，你知道，其中有些人简直对科学如饥似渴。我不明白为什么会这样。也许所有学科都是如此。比如说，很多人都热爱音乐，而我却从来唱不成调。这让我丧失了许多乐趣。我觉得，那些觉得科学枯燥的人同样丧失了很多乐趣。就科学而言，我认为让它变得非常困难的原因之一，是需要大量的想象力。要想象事物真实的面貌究竟有多么疯狂，是非常困难的。没有任何事物是它表面看起来的样子。我们已经习惯了冷和热之类的概念。热和冷其实就是原子振动的速度。原子振动越快，对应的温度就越高；振动越慢，温度就越低。所以如果你有一堆原子，比如桌上放着一杯咖啡什么的，咖啡里的原子在剧烈振动，它们撞击杯子，杯子就开始振动，杯子里的原子也跟着振动，它们又撞击碟子，热量就这样传给了杯子，传给了其他所有东西。

[段 2]

That hot thing spreads its heat into other things by mere contact, because the atoms that are jiggling a lot in the hot thing shake the ones that are jiggling only a little bit in the cold thing, so that the hot heat, we say, goes into the cold thing. It spreads. But what’s spreading is just jiggling and irregular motions, which is easy to understand. It brings up another thing that’s kind of curious. I say that things jiggle, and if you’re used to balls bouncing, you know they slow up and stop after a while. But we have to imagine with the atoms a perfect elasticity. They never lose any energy. Every time they bounce, they keep on bouncing all the time. They don’t lose anything. They’re perpetually moving. The things that happen when we say something loses energy, if a ball comes down and bounces, it shakes irregularly some of the atoms in the floor, and then when it comes up again, it leaves some of those atoms moving, jiggling. So as it bounces, it’s passing its extra energies, its extra motions, to little patches on the floor each time it bounces and loses a little each time, until it settles down, we say, as if all the motion has stopped.

[译文 2]

那个热的东西通过单纯的接触把热量传给其他东西，因为热物体中振动剧烈的原子，会摇动冷物体中振动微弱的原子，所以我们说热量传入了冷东西。热量在扩散。但扩散开去的只不过是振动和不规则的运动，这很容易理解。这引出了另一个有点奇妙的问题。我说物体在振动，如果你习惯了球的弹跳，你知道它们会减速并最终停下。但对于原子，我们必须想象一种完美的弹性。它们从不损失任何能量。每次弹跳，它们都会一直跳下去。它们没有任何损耗。它们在永不停歇地运动。当我们说某物损失了能量时发生的事情——比如一个球落下来弹跳，它会不规则地摇动地板中的一些原子，然后当它再弹起来时，它留下了一些原子在运动、振动。所以随着每次弹跳，它都在把自己多余的能量、多余的运动传递给地板的一小块区域，每次弹跳损失一点，直到我们说它停下来了，仿佛所有的运动都停止了。

[段 3]

But what’s left is the floor is shaking more than it was before, and the atoms in the ball are shaking more than they were before, that the organized motion of all these atoms moving the same way, falling down, and the quiet floor is now transformed into a ball sitting on the ground, but all that emotion is still there in a form, or the energy of motion, in the form of the jiggling of the floor, which is a little bit warmer. Unbelievable. But anybody who’s hammered a great deal on something knows that it’s true, that if you pound something and hit it a lot, you can feel the temperature difference. It heats up. It heats up simply because you’re jiggling it. This picture of atoms is a beautiful one that you can keep looking at all kinds of things this way. You see a little drop of water, a tiny drop. And the atoms attract each other. They like to be next to each other. They want as many partners as they can get. Now the guys that are at the surface have only partners on one side, here, in the air on the other side, so they’re trying to get in.

[译文 3]

但留下来的是地板比以前振动得更厉害了，球里的原子也比以前振动得更厉害了——所有原子朝着同一方向运动的、下落的整齐运动，和原本安静的地板，现在转变成了球静静地待在地面上，但所有的运动依然以某种形式存在，或者说运动能量，以地板振动的形式存在，地板稍微变热了一点。不可思议。但任何一个用力锤击过东西的人都知道这是真的，如果你反复敲打某个东西，你能感觉到温度的变化。它变热了。它变热仅仅是因为你在让它振动。原子的这幅图景是美丽的，你可以一直用这种方式去观察各种各样的事物。你看到一滴水，一小滴水。原子之间互相吸引。它们喜欢彼此待在一起。它们想要尽可能多的伙伴。现在，处于表面的原子只有一侧有伙伴，另一侧是空气，所以它们拼命想挤进去。

[段 4]

And you can imagine this team of people, these teeming people, all moving very fast, all trying to get to have as many partners as possible. And the guys at the edge are very unhappy and nervous. And they keep pounding in, trying to get in. And that makes it a tight ball instead of a flat. And that’s what, you know, surface tension. When you realize, when you see how sometimes a water drop sits like this on a table, then you start to imagine why it sits like that. Because everybody’s trying to get into the water. And at the same time while all this is happening, there are these atoms that are leaving the surface, and the water drop is slowly disappearing. Okay. I find myself trying to imagine all kinds of things all the time, and I get a kick out of it just like a runner gets a kick out of sweating. I get a kick out of thinking about these things. I can’t stop. I mean, I could talk forever. You’re cooled off the water, so the jiggling is less and less and the jiggle is slower and slower. Then the atoms get stuck in place.

[译文 4]

你可以想象这群人，这些熙熙攘攘的人，都在快速移动，都试图拥有尽可能多的伙伴。边缘的那些人非常不安和紧张。它们不断往里冲，试图挤进去。这使得水形成一个紧致的球体而不是扁平的形状。这就是所谓的表面张力。当你意识到，当你看到有时候一滴水在桌上保持这样的形状，你开始想象为什么它会那样。因为每个人都在试图进入水中。与此同时，在所有这些发生的过程中，有些原子正在离开水面，水滴在慢慢地消失。好吧。我发现自己在不断地想象各种各样的事情，而且我从中获得乐趣，就像跑步者从出汗中获得乐趣一样。我从思考这些事情中获得乐趣。我停不下来。我是说，我可以永远讲下去。你冷却了水，所以振动越来越少，振动越来越慢。然后原子就被固定在原地了。

[段 5]

They like to be with their friend. There’s a force of attraction, and they get packed together. They’re not rolling over each other. They’re in a nice pattern, like oranges in a crate, in a nice organized pattern, all just jiggling in place, but not having enough motion to get loose of their own place and to break the structure down. And that’s what I’m describing as a solid. It’s ice. It has a structure. If you held the atoms at one end in a certain position, all the rest are lined up in a position sticking out, and it’s solid at the end. Whereas if you heat that harder, then they begin to get loose and roll all over each other, and that’s the liquid. And if you heat that still harder and they bounce harder, then they simply bounce apart from each other, and they’re just individual, I say atoms, there’s really little groups of atoms, molecules, which come flying and hit, and although they have a tendency to stick, they’re moving too fast, their hands don’t grab, so to speak, as they pass, and they fly apart again, and this is the gas we call steam. You can get all kinds of understanding.

[译文 5]

它们喜欢和朋友待在一起。有一种吸引力，它们被紧密地排列在一起。它们不会互相翻滚。它们排列成整齐的图案，就像箱子里的橙子，一个整齐有序的图案，全都在原地振动，但没有足够的运动来挣脱自己的位置、破坏结构。这就是我所描述的固体。它是冰。它有结构。如果你把一端的原子固定在某个位置，其余的原子都排列在向外突出的位置，末端就是固体。而如果你进一步加热，它们就开始松动，互相翻滚，这就是液体。如果你再进一步加热，它们振动得更猛烈，就会彼此弹开，各自独立，我说的是原子，其实是小群原子，也就是分子，它们飞来飞去地碰撞，虽然它们有相互黏附的倾向，但它们运动太快，可以说，当它们彼此掠过时手抓不住对方，又飞开了，这就是我们所说的气体——蒸汽。你可以从中获得各种各样的理解。

[段 6]

When I was a kid with this air, which I was always interested in, I noticed that when I pumped up my tires on the bicycle – you can learn a lot by having a bicycle – I’d pump up the tires, and the pump would get hot. And that also understandably, as the pump handle comes down and the atoms are coming up against it and bouncing off, and it’s moving in, the ones that are coming off have a bigger speed than the ones that are coming in, so that as it comes down, each time they collide, it speeds them up. And so they’re hotter. When you compress the gas, it heats. And when you pull the piston back out, then atoms which are coming fast at the piston feel a receding or sort of a give, it gives, and it comes out with less energy. It’s like going up against something which is soft and yielding. It goes boom, boom, and it loses. So as you pull the piston out and the atoms are hit, they lose their speed and they cool off. And gas is cool when they expand. And the fun of it is that all these things which you see or notice in the world about it, the pump heats the gas, or the gas cools when it expands, or the steam evaporates, until you cover the cover, and all these things you can understand from these simple pictures.

[译文 6]

小时候，我对空气一直很感兴趣，我注意到当我给自行车轮胎打气时——拥有一辆自行车能学到很多东西——我打气的时候，打气筒会变热。这同样可以理解，当气筒手柄向下压时，原子撞击它然后弹回来，并且正在向内运动，弹回来的原子比进入时速度更大，所以每次碰撞都会让它们加速。因此它们温度更高了。当你压缩气体时，它会变热。当你把活塞向外拉时，快速撞击活塞的原子感觉到一个后退的、可以说是让步的东西，它以较少的能量出来。就像撞上一个柔软有弹性的东西。砰，砰，它就输了。所以当你把活塞拉出来，原子被撞击后，它们失去了速度，就冷却下来。气体膨胀时会变冷。有趣的是，你在世界上看到的或注意到的所有这些现象——气筒让气体变热，或者气体膨胀时冷却，或者蒸汽蒸发，直到你盖上盖子——所有这些你都能从这些简单的图景中理解。

[段 7]

And that’s kind of a lot of fun to think about. I don’t want to take this stuff seriously. I think we should just have fun imagining it and not worry about it. There’s no teacher going to ask you questions at the end. Otherwise, it’s a horrible subject. The atoms like each other, the different degrees. Oxygen, for instance, in the air would like to be next to carbon, and if they get in near each other, they snap together. If they’re not too close, though, they repel and they go apart, so they don’t know that they could snap together. It’s just as if you had a ball, it was trying to climb the hill, and there was a hole it could go into, like a volcano hole, a deep one. It’s rolling along, it doesn’t go down in the deep hole because if it starts to climb the hill and then rolls away again. But if you made it go fast enough, it’ll fall into the hole. And so if it’s something like wood in oxygen, there’s carbon in the wood from a tree, and the oxygen comes and hits it, carbon, but not hot enough, it just goes away again.

[译文 7]

思考这些是很有趣的。我不想把这些东西看得太严肃。我觉得我们应该享受想象的乐趣，不必担心什么。不会有老师在最后提问你。不然的话，这就是一门可怕的课程。原子之间彼此喜欢，程度各不相同。比如说，空气中的氧气喜欢靠近碳，如果它们靠得很近，它们就会迅速结合。但如果它们不够近，它们就会排斥并分开，所以它们不知道自己其实可以迅速结合。就好像你有一个球，它正试图爬上一座山，山上有一个可以落入的坑，像一个火山口，很深的那个。它滚来滚去，并没有掉进深坑里，因为如果它开始爬山然后又滚开了。但如果你让它运动得足够快，它就会掉进坑里。所以如果是木头在氧气中，木头里有来自树木的碳，氧气过来撞击碳，但温度不够高，它就又离开了。

[段 8]

The air is always coming. Nothing’s happening. If you can get it faster by heating it up somehow, somewhere, somehow, get it started, a few of them come fast. They go over the top, so to speak. They come close enough to the carbon and snap in. And that gives a lot of jiggly motion, which might hit some other atoms, making those go faster so they can climb up and bump against other carbon atoms. And they jiggle and they make others jiggle, and you get a terrible catastrophe, which is one after the other. All these things are going faster and faster and snapping in, and the whole thing is changing. That catastrophe is a fire. It’s just a way of looking at it. And these things are happening. They’re perpetual. Once it gets started, it keeps on going. The heat makes the other atoms capable of reaching to make more heat, to make other atoms, and so on. So this terrible snapping is producing a lot of jiggling. And if I put, with all that activity of the atoms there, and I put a cup of coffee over that mess of wood that’s doing this, it’s going to get a lot of jiggling.

[译文 8]

空气一直在涌来。什么事也没发生。如果你能通过某种方式、在某个地方、以某种方法加热让它变快，让反应启动，一些原子就会快速运动。可以说，它们翻越了山顶。它们足够接近碳并迅速结合。这产生了大量的振动运动，可能撞击其他原子，使它们也加速，这样就能爬升并撞击其他碳原子。它们振动，又让其他原子振动，你得到了一场可怕的灾难，一个接一个地发生。所有这些东西越来越快地运动并结合，整个局面都在改变。那场灾难就是火。这只是看待它的一种方式。这些事情正在发生。它们是永恒的。一旦开始，就会持续下去。热量使其他原子有能力去产生更多热量，去影响其他原子，如此循环。所以这种可怕的结合产生了大量的振动。如果我放一杯咖啡在那堆正在发生所有这些原子活动的木头上方，它会获得大量的振动。

[段 9]

So that’s what the heat of the fire is. Then of course, you see this is what happens when you start to think, you just go on and on, you wonder where, how did it get started? Why is it that the wood’s been sitting around all this time with the oxygen all this time and it didn’t do this earlier or something? Where did I get this from? Well, it came from a tree. And the substance of a tree is carbon. Where did that come from? That comes from the air, carbon dioxide from the air. People look at trees and they think it comes out of the ground, that plants grow out of the ground. But if you ask where the substance comes from, you find out where do they come from? The trees come out of the air? They surely come out of the air. No, they come out of the air. The carbon dioxide in the air goes into the tree and it changes it, kicking out the oxygen and pushing the oxygen away from the carbon and leaving the carbon substances with water. Water comes out of the ground, you see. Only it had to get in there.

[译文 9]

这就是火的热量是怎么回事。然后当然，你看到当你开始思考的时候，你就会一直想下去，你想知道，它是怎么开始的？为什么木头一直在那里待了这么久，氧气也一直在那里待了这么久，它却没有早点发生这样的事？我从哪里得到这个东西的？嗯，它来自一棵树。而树的物质成分是碳。那碳又从哪里来？它来自空气，空气中的二氧化碳。人们看着树，以为它来自泥土，以为植物是从泥土里长出来的。但如果你问那些物质从哪里来，你会发现它们到底从哪里来？树是从空气中长出来的？它们确实是从空气中来的。不，它们就是从空气中的。空气中的二氧化碳进入树里面，然后树改变了它，把氧气踢出去，把氧气从碳那里推开，留下碳的物质和水。水是从地里面来的，你看。只是水必须得先进入树里面才行。

[段 10]

It came out of the air, didn’t it? It came down from the sky. So in fact, most of a tree, almost all of the tree, is out of the ground. I’m sorry, it’s out of the air. There’s a little bit from the ground, some minerals and so forth. Now of course I told you the oxygen, and we know the oxygen and carbon stick together very tight. How is it the tree is so smart as to manage to take the carbon dioxide, which is the carbon oxygen nicely combined, and undo that so easy? Ah, life, life has some mysterious force. No, the sun is shining. And it’s the sunlight that comes down and knocks this oxygen away from the carbon. So it takes sunlight to get the plant to work. And so the sun all the time is doing the work of separating the oxygen away from the carbon. Oxygen is some kind of terrible byproduct which it spits back into the air and leaves carbon and water and stuff to make the substance of the tree. Then when we take the substance of the tree and stick it in the fireplace, and there’s all the oxygen made by these trees and all the carbon would much prefer to be close together again, and once you let the heat to get it started, it continues and makes an awful lot of activity while it’s going back together again, and all this nice light and everything comes out and everything is being undone.

[译文 10]

它来自空气，不是吗？它是从天上降下来的。所以事实上，一棵树的大部分，几乎是全部，都来自地面。抱歉，是来自空气。有少量来自地面，一些矿物质等等。现在当然我告诉过你氧气，我们知道氧和碳结合得非常紧密。树怎么这么聪明，能够把二氧化碳——也就是碳和氧好好结合在一起的二氧化碳——这么容易就拆开？啊，生命，生命有一种神秘的力量。不，是太阳在照耀。是阳光照下来，把这个氧从碳那里打走。所以需要阳光才能让植物工作。所以太阳一直在做把氧从碳那里分离出来的工作。氧气是一种可怕的副产物，被树吐回空气中，留下碳和水和物质来构成树的物质。然后当我们把树的物质拿来放进壁炉里，那里有这些树制造出来的所有的氧，而所有的碳都非常想要重新再靠近一起，一旦你让热量引发了反应，它就会继续下去，在重新结合的过程中产生大量的活动，所有这些美好的光都释放出来，一切都在被逆转。

[段 11]

You’re going back from carbon and oxygen back to carbon dioxide, and the light and heat that’s coming out, that’s the light and heat of the sun that went in. So it’s sort of stored sun that’s coming out when you burn a log. Next question, how is it the sun is so jiggly, so hot? I got to stop somewhere. I’ll leave you something to imagine. Most elastic things like steel springs and so on is nothing but this electrical thing pulling back. You pull the atoms a little bit apart when you bend something, and then they try to come back together again. But rubber bands work on a different principle. There, there’s some long molecules like chains, and other little ones that are shaking all the time that are bombarding them, these chains. And the chains are all kind of kinky and knocked about and shake. When you pull open the rubber band, the strings get straighter. But these strings are being bombarded on the side by these other atoms trying to shorten them by kinking them. So it pulls back. It’s trying to pull back, and it’s pulling back only because of the heat. So if you heat a rubber band, it’ll pull more strongly, for instance.

[译文 11]

你从碳和氧回到二氧化碳，而释放出来的光和热，就是曾经进去的太阳的光和热。所以当你燃烧一根木头的时候，释放出来的可以说是储存起来的太阳。下一个问题，太阳为什么这么活跃，这么热？我得在某个地方停下来，留一些东西让你们去想象。大多数有弹性的东西，比如弹簧钢等等，无非就是这种电的东西在拉回来。当你弯曲什么东西的时候，你把原子稍微拉开了一点，然后它们就试图重新再靠近一起。但橡皮筋的工作原理不同。在那里，有一些像链条一样的长分子，还有其他一直在振动的小分子在不停地轰击这些链条。而这些链条都是扭结的、被撞来撞去的、抖动的。当你拉开橡皮筋的时候，这些链条变得更直了。但这些链条正在被其他原子从侧面轰击，这些原子试图通过扭结来使它们缩短。所以它就往回拉。它试图往回拉，它之所以往回拉完全是因为热。所以如果你加热一根橡皮筋，它会拉得更紧，比如说。

[段 12]

If you hang a weight with a rubber band and put a little match to it, it’s kind of fun to watch it rise, the way it heats more. And there’s another thing you can check that this idea is right, that it’s heat that drives a rubber band. If you pull the band out, just like when we push the piston in the gas, if you pull the band out, the tightening string hitting those molecules makes them move faster, and so it’s warmer. And if you take the band and let it in, then the molecules hitting the strings which sort of give as the thing hits, they give in to the soft like, and they lose energy when they hit these retiring strings. So it cools. And there is a little way you can do this. You’re not very sensitive. It’s a small effect. And if you take a fairly wide rubber band and put it between your lips and pull it out, you’ll certainly notice it’s hotter. And if you then hold it out and let it in, you’ll notice it’s cooler. At least you’ll notice a certain difference in what happens when you expand it, when you contract it.

[译文 12]

如果你用橡皮筋吊一个重物，然后拿一根火柴去加热它，看着它上升是很有趣的，因为它受热更多了。还有另一件事你可以验证这个想法是对的，就是热驱动了橡皮筋。如果你把橡皮筋拉开，就像我们把活塞推入气体中一样，如果你把橡皮筋拉开，收紧的链条撞击那些分子使它们运动得更快，所以它就更热。而如果你把橡皮筋让它收缩回来，那么撞击链条的分子——链条在撞击时有点像退让——它们在撞击这些退让的链条时失去能量。所以它冷却了。有一个小方法可以做到这个。你不是很敏感。这是一个很小的效果。如果你拿一根比较宽的橡皮筋放在嘴唇之间拉开，你肯定会注意到它更热了。然后如果你把它放在外面让它收缩回来，你会注意到它更凉了。至少你会在它膨胀和收缩的时候注意到一定的差异。

[段 13]

And I’ve always found rubber bands fascinating to think that when they’re sitting on an old package of papers for a long time, holding those papers together, it’s done by a perpetual pounding, pounding, pounding of the atoms against these chains, trying to kink them and trying to kink them year after year. Well, rubber bands don’t last that long, but anyhow, for a long time, trying to hold this whole thing together. The world is a dynamic mess of jiggling things if you look at it right. If you magnify it, you can hardly see anything anymore because everything is jiggling, and they’re all in patterns, and they’re all lots of little balls, and it’s lucky that we have such a large scale view of everything that we can see them as things without having to worry about all these little atoms all the time. If you get hold of two magnets and you push them, you can feel this pushing between them. Turn it around the other way and they slam together. Now, what is it, the feeling between those two magnets? What do you mean, what’s the feeling between the two magnets? Well, there’s something there, isn’t there?

[译文 13]

我一直觉得橡皮筋很引人入胜，想想看，当它们放在旧纸包上很长时间，把那些纸固定在一起的时候，是通过原子不停地、不停地、不停地轰击这些链条，试图扭结它们，年复一年地试图扭结它们。嗯，橡皮筋持续不了那么久，但不管怎样，在很长的时间里，试图把所有这些东西固定在一起。如果你正确地看这个世界，它是一团动态的混乱的振动的东西。如果你把它放大，你几乎什么都看不见了，因为一切都在振动，它们都有各种模式，它们都是很多小球，幸好我们有这么大尺度的视角来看待一切，把它们看作东西，而不用一直担心所有这些小原子。如果你拿两个磁铁推它们，你能感觉到它们之间的推力。换个方向它们就猛地吸在一起。那么，这两个磁铁之间的感觉是什么？你什么意思，两个磁铁之间的感觉是什么？嗯，那里有东西，不是吗？

[段 14]

I mean, the sensation is that there’s something there when you push these two magnets together. Listen to my question. What is the meaning when you say that there’s a feeling? Of course you feel it. Now, what do you want to know? What I want to know is what’s going on between these two bits of metal. The magnets repel each other. Well, then, what does that mean, or why are they doing that, or how are they doing it? You’re asking… I must say, I think that’s a perfectly reasonable question. Of course it’s a reason. It’s an excellent question. Okay? Right? But the problem that you’re asking… you see, when you ask why something happens, how does a person answer why something happens? For example, Aunt Minnie is in a hospital. Why? Because she slipped, she went out and she slipped on the ice and broke her hip. That satisfies it, people. It satisfies, but it wouldn’t satisfy someone who came from another planet, knew nothing about things. At first, you don’t understand why, when you break your hip, do you go to the hospital? How do you get to the hospital when the hip is broken?

[译文 14]

我的意思是，当你把这两个磁铁推在一起的时候，感觉那里有东西。听我的问题。你说有感觉的时候是什么意思？你当然感觉到了。那么你想知道什么？我想知道的是这两块金属之间发生了什么。磁铁互相排斥。那么，那是什么意思，或者它们为什么这样做，或者它们是怎么做到的？你在问……我必须说，我认为这是一个完全合理的问题。当然有原因。这是一个很好的问题。好吗？对吧？但你问的问题是……你看，当你问为什么某件事发生的时候，一个人怎么回答为什么某件事发生呢？比如说，明妮阿姨在医院里。为什么？因为她滑倒了，她出去在冰上滑倒了，摔断了髋骨。这让人们满意了。这让人满意，但这不会让一个来自另一个星球、什么都不知道的人满意。首先，你不明白为什么，当你摔断髋骨的时候，你要去医院？髋骨断了你怎么去医院？

[段 15]

Well, because her husband, seeing that she had the hip broken, called the hospital up and sent somebody to get her. All that is understood by people. Now when you explain a why, you have to be in some framework that you allow something to be true. Otherwise you’re perpetually asking why. Why did the husband call up the hospital? Because husband is interested in his wife’s welfare. Not always, some husbands aren’t interested in their wife’s welfare, and they’re drunk and they’re angry. And so you begin to get a very interesting understanding of the world and all its complications. If you try to follow anything up, you go deeper and deeper in various directions. For example, you could go, why did she slip on the ice? Well, ice is slippery. Everybody knows that, no problem. But you ask, why is ice slippery? That’s kind of curious. Ice is extremely slippery. It’s very interesting. You say, how does it work? You could either say, I’m satisfied that you’ve answered me, ice is slippery, that explains it, or you could go on and say why is ice slippery, and then you’re involved with something because there aren’t many things as slippery as ice.

[译文 15]

嗯，因为她的丈夫，看到她的髋骨断了，打电话叫了医院，派人来接她。所有这些人们都理解。现在当你解释一个为什么的时候，你必须处于某个框架之内，你允许某些事情是真的。否则你就会一直问为什么。为什么丈夫打电话给医院？因为丈夫关心妻子的健康。不总是这样，有些丈夫不关心他们妻子的健康，他们喝醉了，很生气。所以你就开始对这个世界及其所有的复杂性有了一个非常有趣的理解。如果你试图追究任何事情，你就会越来越深入各个方向。比如，你可以问，她为什么在冰上滑倒？嗯，冰很滑。每个人都知道，没问题。但你问，为什么冰很滑？那有点好奇。冰极其非常滑。非常有趣。你说，它是怎么运作的？你可以说，我满意你的回答了，冰很滑，这就解释了，或者你可以继续问为什么冰很滑，然后你就被牵连进去了，因为没有多少东西像冰那么滑。

[段 16]

It’s very hard to get greasy stuff, but that’s sort of wet and slimy, but a solid that’s so slippery because it is, in the case of ice, that when you stand on it, they say momentarily the pressure melts the ice a little bit, so you got a sort of instantaneous water surface on which you’re slipping. Why on ice and not on other things? Because ice expands when it, water expands when it freezes, so the pressure tries to undo the expansion and melts it. It’s capable of melting it, but other substances contract when they’re freezing, and when you push them, they’re just satisfied to be solid. Why does water expand when it freezes and other substances don’t expand when they freeze. All right? I’m not answering your question, but I’m telling you how difficult the why question is. You have to know what it is that you’re permitted to understand and allow to be understood and known, and what it is you’re not. You’ll notice in this example that the more I ask why, it gets interesting after all. That’s my idea, that the deeper the thing is, the more interesting it is. And we could even go further and say, why did she fall down when she slipped?

[译文 16]

很难找到油腻的东西，但那种是湿的、黏糊糊的，但一种固体这么滑是因为，就冰来说，当你站在上面的时候，他们说压力瞬间融化了一点点冰，所以你有一个即时的水面上你在上面滑倒。为什么在冰上而不在其他东西上？因为冰膨胀，水结冰时会膨胀，所以压力试图逆转膨胀并融化它。它能够融化它，但其他物质结冰时会收缩，当你压它们的时候，它们就满意地保持固体状态。为什么水结冰时膨胀而其他物质结冰时不膨胀。好吗？我没有回答你的问题，但我告诉你为什么这个问题有多难。你必须知道什么是你被允许理解和允许了解和知道的，以及什么不是。你在这个例子中会注意到，我问的为什么越多，它终究变得有趣了。这就是我的想法，事物越深，它就越有趣。我们甚至还可以进一步问，她滑倒的时候为什么摔倒？

[段 17]

That has to do with gravity and involves in all the planets and everything else. Never mind. It goes on and on. Now when you ask, for example, why two magnets repel, there are many different levels. It depends on whether you’re a student of physics or an ordinary person who doesn’t know anything or not. If you’re somebody who doesn’t know anything at all about it, all I can say is that there’s a magnetic force that makes them repel, and that you’re feeling that force. You say, but that’s very strange because I don’t feel a kind of force like that in other circumstances. When you turn them the other way, they attract. There’s a very analogous force, electrical force, which is the same kind of a question, and you say that’s also very weird, but you’re not at all disturbed by the fact that when you put your hand on the chair, it pushes you back. But we found out by looking at it that that’s the same force, as a matter of fact, the electrical force, not magnetic exactly in that case, but it’s the same electrical repulsions that are involved in keeping your finger away from the chair because everything’s made out of, it’s electrical forces in minor and microscopic details.

[译文 17]

这与引力有关，涉及所有行星和其他一切。不必多说了。这些力无穷无尽。那么当你问，比如说，为什么两块磁铁会相互排斥，这有很多不同的解释层次。取决于你是一个物理学学生，还是一个什么都不懂的普通人。如果你对此一无所知，我所能说的就是存在一种磁力使它们相互排斥，而你感受到的就是那种力。你说，但这很奇怪，因为我在其他情况下并没有感受到这样的力。当你把磁铁换一个方向，它们就相互吸引。还有一种非常类似的力，即电力，也是同样的问题，你也会觉得那很奇怪，但你并不会因为你把手放在椅子上、椅子把你推回去而感到困扰。但我们通过观察发现，那其实就是同一种力，事实上就是电力，严格来说不完全是磁力，但正是同样的电力排斥在阻止你的手指靠近椅子，因为一切都是由——在微观细节上都是电力在起作用。

[段 18]

There’s other forces involved, but this is connected to electrical forces. It turns out that the magnetic and the electric force with which I wish to explain these things, this repulsion in the first place, is what ultimately is the deeper thing that we have to start, that we can start with to explain many other things that looked like they were, everybody would just accept them, you know. You can’t put your hand through the chair, that’s taken for granted, but that you can’t put your hand through the chair, when looked at more closely, why, it involves these same repulsive forces that involve these same repulsive forces that appear in magnets. The situation you then have to explain is why in magnets it goes over a bigger distance than ordinarily. And there it has to do with the fact that in iron all the electrons are spinning in the same direction. They all get lined up, and they magnify the effect of the force until it’s large enough at a distance that you can feel it. But it’s a force which is present all the time and very common, and is in a basic force of almost. I mean, I can go a little further back if I were more technical.

[译文 18]

还涉及其他力，但这与电力有关。事实证明，磁力和电力——我最初想用来解释这些现象的排斥力——最终才是更深层的东西，我们必须从它出发，用它来解释许多其他看起来大家都习以为常的现象。你无法把手穿过椅子，这被认为是理所当然的，但为什么你无法把手穿过椅子，仔细一看，这涉及的就是与磁铁中出现的相同的排斥力。那么你需要解释的是，为什么磁铁中的这种力能跨越比通常更大的距离。这与铁中所有电子都朝同一方向旋转有关。它们全部排列整齐，将力的效果放大，直到在远处变得足够大，你能感觉到它。但它是一种始终存在、非常基本的力。我是说，如果我从技术角度再深入一点的话。

[段 19]

But at an early level, I just have to tell you that’s going to be one of the things you’ll just have to take as an element in the world, the existence of magnetic repulsion or electrical attraction, magnetic attraction. I can’t explain that attraction in terms of anything else that’s familiar to you. For example, if we say the magnets attract like as if they were connected by rubber bands, I would be cheating you because they’re not connected by rubber bands. I shouldn’t be in trouble. You’d soon ask me about the nature of the bands. And secondly, if you were curious enough, you’d ask me why rubber bands tend to pull back together again, and I would end up explaining that in terms of electrical forces, which are the very things that I’m trying to use the rubber bands to explain. So I have cheated very badly, you see. So I’m not going to be able to give you an answer to why magnets attract each other, except to tell you that they do, and to tell you that that’s one of the elements in the world of different kinds of forces. There are electrical forces, magnetic forces, gravitational forces, and others, and those are some of the parts.

[译文 19]

但在初级阶段，我只能告诉你，你只能把它当作世界的一个基本要素来接受，即磁排斥或电吸引、磁吸引的存在。我无法用你熟悉的其他任何东西来解释那种吸引。比如说，如果我们说磁铁的吸引就像它们被橡皮筋连在一起，那我在欺骗你，因为它们并没有被橡皮筋连在一起。我不应该陷入困境。你很快就会问我橡皮筋的本质是什么。其次，如果你足够好奇，你会问我为什么橡皮筋倾向于收缩回来，我最终会用电力的性质来解释，而这恰恰是我试图用橡皮筋来解释的东西。所以你看，我作弊得非常厉害。所以我无法给你一个磁铁为什么相互吸引的答案，只能告诉你它们确实会相互吸引，并告诉你那是世界上不同类型力中的一种。有电力、磁力、引力等等，这些都是其中的一部分。

[段 20]

If you were a student, I could go further. I could tell you that the magnetic forces are related to the electrical forces very intimately, that our relationship between the gravity forces and electrical forces remains unknown, and so on. But I really can’t do a good job, any job, of explaining magnetic force in terms of something else that you’re more familiar with, because I don’t understand it in terms of anything else that you’re more familiar with. This stuff of fantasizing and looking at the world, imagining things, which really isn’t fantasizing because you’re only trying to imagine the way it really is, comes in handy sometimes. The other day I was at the dentist, and he’s getting ready with his electric drill to make holes, and I thought I better think of something fast or else it’s going to hurt. And then I thought about this little motor going around, and what was it that made it turn, and what was going on. And what’s going on is there’s a dam some distance away here, and water going over the dam turns a great big wheel. And this wheel is connected with long, thin pieces of copper, which split up into other pieces of copper and split up and spread all over the city.

[译文 20]

如果你是学生，我可以讲得更深入。我可以告诉你磁力与电力有着非常密切的关系，而引力与电力之间的关系仍然未知，等等。但我真的无法很好地——根本无法——用你更熟悉的其他东西来解释磁力，因为我自己也无法用你更熟悉的东西来理解它。这种幻想和观察世界、想象事物的做法，其实算不上幻想，因为你只是在试图想象事物真实的面貌，有时确实很有用。前几天我在牙医那里，他正准备用电钻给我钻洞，我想我最好赶快想点别的，不然会很疼。然后我就想到那个小马达在转动，是什么让它转动，发生了什么。发生的事情是，在远处有一个水坝，水流过水坝推动一个巨大的轮子。这个轮子由长长的细铜片连接，这些铜片分支成其他铜片，再分支、扩散到整个城市。

[段 21]

And then they’re connected back through another little gadget that makes wheels turn. All the wheels of the city are turning because this thing turns. If this thing stops, all the wheels stop. It starts again, they all start again. And I think that’s kind of a marvelous thing of nature. It’s kind of, it’s extremely curious, that phenomenon. I like to think about a lot because all it is is copper and iron, see. Sometimes we think it’s a man-made generator, it’s very complicated, the phenomenon is the result of some special something that we made, but it’s nature doing it, and it’s just iron and copper. And if you took a big long loop of copper and had iron at each end and moved a piece of iron here, the other iron moves at the other piece. And if you get it down to the nothing, just moving a piece of iron in a loop of copper and seeing another piece of iron move, you realize what a fantastic mystery nature is. You don’t even need the iron. You could, if you at least get this pump primed and started by jiggling copper strands around fast enough, knotting them and unknotting them and so forth, you can get other copper strands to move at the other end of a long connection.

[译文 21]

然后它们通过另一个小装置连接回去，使轮子转动。城市里所有的轮子都在转动，因为那个东西在转动。如果那个东西停了，所有的轮子都停。它重新启动，所有的轮子也重新启动。我觉得这是自然界一种非常奇妙的东西。这种现象极其有趣。我喜欢经常思考它，因为它不过是铜和铁，你知道吗。有时我们认为是人造发电机，很复杂，这种现象是我们制造出的某种特殊东西的结果，但这是自然界在做，仅仅是铁和铜。如果你拿一长圈铜线，两端各放一块铁，移动这边的一块铁，另一边的铁也会移动。如果你把它简化到极致，仅仅是在一圈铜线中移动一块铁，看到另一块铁移动，你会意识到自然界是多么不可思议的神秘。你甚至不需要铁。如果你至少能通过快速搅合铜线、打结再解开等方式让这个泵启动起来，你就能让另一端的铜线也动起来。

[段 22]

And what is it? It’s only copper and motion. And we’re so used to circumstances in which these electrical phenomena are all cancelled out. Everything’s sort of neutral, pushing and pulling. It’s really very dull. But nature has these wonderful things, magnetic forces and electrical, because you comb your hair with your comb and you get some strange condition. So you put it in front of a piece of paper and it lifts up the paper, where the paper jiggles at a distance far away. And that’s, in fact, turns out, that that is the thing that’s more deeper inside of everything than the things we’re used to. We’re used to forces that only act directly, right? You push with your finger, it only acts directly. But then you have to imagine what it is that’s pushing with the finger. Here’s this little finger made out of little balls and atoms. And it’s got another bunch of atoms that I’m pushing. And there’s a little space between those atoms. And this pushing is going through that space. And the only thing that happens with the comb and the paper is that circumstances have arisen, which make it possible to see that these forces go through a bigger distance than just the short distance between the atoms.

[译文 22]

那是什么？那不过是铜和运动。我们已经习惯了电力现象全部被抵消的情况。一切都是中性的，推和拉。真的很乏味。但自然界有这些奇妙的东西，磁力和电力，因为你用梳子梳头时会产生某种奇怪的状态。然后你把它放在一张纸片前面，它能把纸片吸起来，纸片在远处颤动。事实上，这证明它是比我们习以为常的事物更深层的、存在于一切事物内部的东西。我们习惯于只直接作用的力，对吧？你用手指推，它只直接作用。但你得想象是什么在推动手指。这个小小的手指由小球和原子组成。还有另一堆原子是我在推的。这些原子之间有一点间隙。这个推力穿过那个间隙。梳子和纸片所发生的情况只是，环境条件使得我们可以看到这些力穿过的距离比原子之间的短距离要大得多。

[段 23]

What it is, is they have charges like electrons that are both the same. They repel each other with a force. They’re little tiny particles. They’re a piece of the atom. And they repel each other with a force which is enormous. It’s inversely as the square of the distance, just like gravity is inversely as the square of the distance. But gravity is attractive. And this is repulsive. And for two electrons, the gravity is so weak compared to the electricity. Electricity is so much more enormous than the gravity. I can’t express it because I don’t know the name of the number. It’s one with 30 or 8 or 40 zeros after the one. Bigger is electricity. It’s so enormous that if I were all electrons, well, the numbers are too big. So if there’s also, however, for electrical things, other kind of charge, positive charges, an example of protons are positive. They’re inside the nucleus of the atom. And they attract electrons, opposite charges attract and like charges repel. So you have to imagine enormous forces where likes are trying to get away from likes and unlikes are trying to get near the opposite. What would happen if you had a lot of them?

[译文 23]

它们拥有相同的电荷，比如电子。它们以巨大的力相互排斥。它们是极小的粒子。它们是原子的一部分。它们相互排斥的力非常巨大。它与距离的平方成反比，就像引力也与距离的平方成反比一样。但引力是吸引的。而这个力是排斥的。对于两个电子来说，引力与电力相比极其微弱。电力比引力大得多。我无法表达，因为我不知道那个数字叫什么。它是1后面跟着30或8或40个零。电力更大。它是如此巨大，如果我不完全是电子的话——嗯，那些数字太大了。然而，对于电力来说，还有另一种电荷，正电荷，质子的例子就是正的。它们在原子核内部。它们吸引电子，异种电荷相吸，同种电荷相斥。所以你得想象巨大的力，同种电荷试图远离同种电荷，异种电荷试图靠近异种电荷。如果你有很多这样的电荷，会发生什么？

[段 24]

They’d be, all the likes would collect with unlikes. They attract each other. And they’d get an intimate mixture of pluses and minuses all on top of each other, very close together. You wouldn’t have a lot of pluses anywhere because they repel each other. They’ll all be compensated by minuses very close, and you get these little knots of plus and minus. The reason that the knots don’t get smaller and smaller is because they are particles and have quantum mechanical effects that we won’t discuss that makes it that you can’t get any smaller than a certain size. And so you get these little lumps, which are balls. They’re the atoms. The atoms have positive and negative charge, and they’re neutralized. They cancel their charge as nearly as they can. And because of this intimate, this force is so big, it ends up nowhere with very little left because it’s so big it cancels out. There’s always exactly the same pluses and minuses in any normal material. When you comb your hair, it rubs just a little bit extra or just a few extra minuses, say here, and somewhere else a few extra pluses, but the forces are so big, there’s just the extra ones which make a force that we can see that seems to be at a long range.

[译文 24]

它们会全部聚集在一起，同种与异种相互吸引。它们会形成正负电荷紧密混合的状态，彼此非常靠近。你不会在任何地方看到大量正电荷，因为它们相互排斥，它们都会被附近的负电荷抵消，你得到这些正负电荷的小结。这些结不会越来越小的原因是，它们是粒子，具有我们不会讨论的量子力学效应，使得你无法让它们小于某个特定尺寸。所以你得到这些小块，它们是球体。那就是原子。原子带有正电荷和负电荷，它们被中和了。它们尽可能抵消自己的电荷。因为这种紧密的作用，这种力如此巨大，最终几乎没有什么剩余，因为它太大了，抵消了。在任何正常材料中，正电荷和负电荷的数量始终完全相等。当你梳头时，它只是摩擦出一点点多余的——比如说这里多了几个负电荷，其他地方多了几个正电荷，但这些力是如此巨大，只有那些多余的电荷产生了一种我们能看到的长程力。

[段 25]

And that we find mysterious, and that we need an explanation for. And we try to find an explanation for it in terms of ideas like the forces that are inside of rubber bands or steel bars or twisted things. We would like to have some kind of puller at a distance, because we’re used to it, that we don’t get any push until we’re touching. But the fact is that the reason we don’t get any push until we’re touching is it’s the same force as you see in a long distance, only it’s come down to short because the pluses and minuses have canceled out so well that you don’t feel anything until it gets very, very close. When it gets close enough, of course, it makes the difference which is plus and which is minus and where they are, and they repel each other. So it’s kind of fun to imagine this intimate mixture of highly attractive opposites, which are so strong that they cancel out the effects. And it’s only sometimes, when you have an excess of one kind and another, that you get this mysterious electrical force. And how can I explain a mysterious electrical force in any other way?

[译文 25]

这令我们感到神秘，我们需要对此做出解释。我们试图用橡皮筋或钢棒或扭曲物体内部存在某种力这样的概念来解释它。我们倾向于认为存在某种远距离的拉力，因为我们已经习惯了这种模式——在接触之前我们感受不到任何推力。但事实是，我们在接触之前感受不到任何推力，其原因在于，这种力与你所见的远距离作用的力是同一种力，只是由于正负电荷相互抵消得非常好，以至于在距离不够近的时候你根本感觉不到任何东西。当然，当距离足够近时，哪个是正哪个是负、它们在哪里就变得重要起来，它们会相互排斥。因此，想象这种紧密混合的、具有高度吸引力的对立面是很有趣的，它们强大到足以相互抵消彼此的效果。只有在某种电荷过剩时，你才会感受到这种神秘的电力。我还能用其他什么方式来解释这种神秘的电力呢？

[段 26]

Why should I try to explain it in terms of something like jelly or other things which are made, and I understand, the other way around in terms of strong long-distance forces which have all cancelled out? So it’s the electrical forces, in fact, and the magnetic forces, in fact, that we have to accept as the base reality in which we’re going to explain all the other things. So again, it turns out it’s hard to understand. You have to do a lot of imagining. That the real world has as its base a force which acts at a long distance. That we haven’t got much experience with that force. We have peculiar phenomena here and there. But ordinarily, we don’t have much experience with that force is simply because that’s what requires explanation. That’s what requires imagination. The long-distance force we have no other picture for. And in the example of the generator, for instance, what happens is that the electrons, which are part of an atom, they’re pushed by the motion of the copper wires. And it’s wonderful to think that you push a few here and they get too close together, so they push the others because they repel at a long distance.

[译文 26]

为什么我要试图用果冻或其他类似的东西来解释它呢？反过来，我倒是理解用远距离强力——它们已经完全抵消——来解释的方式。所以事实上，电力和磁力才是我们必须接受的基本实在，我们要用它来解释所有其他事物。因此，结果发现这很难理解。你需要进行大量的想象。真实世界的基本力是一种远距离作用的力。我们对这种力没有太多经验。我们在某些地方观察到了一些奇特的现象。但通常我们对这种力缺乏经验，恰恰是因为它才需要解释，它才需要想象力。对于这种远距离的力，我们没有其他可以类比的东西。以发电机为例，所发生的情况是，作为原子一部分的电子被铜线的运动所推动。想到你在的这一端推动几个电子，它们靠得太近了，于是它们因为远距离排斥力而推动其他电子，这真是妙极了。

[段 27]

So it’s not just like water which repels at a short distance, but it’s a wonderful fluid which repels at a long distance, and the effects, therefore, can go very quickly through the wire. If there’s a little concentration, it goes zing through the wire all over the city at once. You can use that stuff to make signals. You can push a few electrons here and there by talking in a telephone. At the other end of the line, a long line of copper across the city, the electrons respond because of these very rapid interactions over these long distances to what you’re saying in this room. And to discover experimentally the existence of these long forces and these rapid motion actions and so forth was a tremendous thing for human beings. I think that the discovery of electricity and magnetism and the electromagnetic effects, which were finally worked out, the full equations for everything was worked out by Maxwell in 1873, is probably the most fundamental transformation of the most remarkable thing in history, the biggest change in history. I went to a scientific school at MIT, and in fraternity, when you first join, they try to keep you from being, if you think you’re smart, from feeling that you’re too smart by giving of what looked like simple questions to try to figure out what actually happens.

[译文 27]

所以它不仅仅像水那样在短距离内排斥，而是一种在远距离内排斥的神奇流体，因此效应可以非常迅速地通过导线传播。如果有一小团聚集，它会一下子嗖地传遍整座城市。你可以利用这种东西来制造信号。你可以通过打电话说话来推动这里的几个电子、那里的几个电子。在线路的另一端，一条横跨城市的长长铜线中，电子会因为这些远距离的快速相互作用而对你在这个房间里说的话做出回应。通过实验发现这些长距离力的存在以及这种快速的运动作用等，对人类来说是一件了不起的事情。我认为，电和磁的发现以及电磁效应的发现——最终的完整方程由麦克斯韦在1873年完成——可能是历史上最根本的转变、最了不起的事情、最大的变革。我在麻省理工学院读科学学校时，在兄弟会里，当你刚加入时，他们会给你一些看似简单的问题来试图弄清楚实际发生了什么，以防止你觉得自己很聪明就自以为是。

[段 28]

And it’s like training for imagination. It’s kind of fun, and I thought I’d tell you some of them that I remember. I learned them. Of course, once you learn them, the next time somebody comes along with this wonderful puzzle, you look at them kind of quietly. You wait two or three seconds or five seconds to show whiz that you were thinking, and then you come up with this answer to astonish your friends. But the fact was, of course, that you were trained by your fraternity brothers as to how to answer these things early on. One of the questions we got was the problem about the mirror. It’s an old-fashioned, it’s an old problem. You look in a mirror, and let’s say you part your hair on the right side. And you look in the mirror, and the image has got its hair part on the left side. So the image is left to right mixed up. It’s not top and bottom mixed up, because the top of the head of the image is up there at the top, and the bottom of the feet are at the bottom. And the question is, how does a mirror know to get the left and right mixed up and not the up and down?

[译文 28]

这就像是对想象力的训练。这很有趣，我想告诉你一些我记得的问题。我学会了它们。当然，一旦你学会了，下次有人带着这个精彩的谜题走过来时，你会安静地看着他们。你等上两三秒或五秒钟来表明你在思考，然后你给出答案来让你的朋友们大吃一惊。但事实是，你早就被你的兄弟们训练过如何回答这些问题了。我们遇到的问题之一是关于镜子的问题。这是一个老式的问题，一个古老的问题。你看着镜子，比如说你在右侧分了头发。你看着镜子，影像的头发分在了左侧。所以影像是左右颠倒的。它不是上下颠倒的，因为影像的头顶在上面，脚底在下面。问题是，镜子怎么知道要弄乱左右而不是上下？

[段 29]

You get a better idea of the problem if you think of lying down and looking at the mirror. All right, your hair is still on the left side, and now the left and right was the up and down, whereas the up and down, which look okay, was the right and left before. The mirror somehow figured out what you’re going to do when you’re looking at it. To describe in a sort of symmetrical way what a mirror does, that it doesn’t look lopsided, and then it takes left and mixes it up with right, and it doesn’t do the same with up and down. And after a lot of fiddling, gradually I knew we worked out the answer to that one. You see, if you wave this hand, then the hand in the mirror that waves is right opposite it. The hand on the east is the hand on the east, and the hand on the west is the hand on the west, and the head that’s up is up, and the feet that are down are down. Everything’s really all right. But what’s wrong, as if this is north. Your nose is to the north of the back of your head, but in the image the nose is to the south of the back of the head.

[译文 29]

如果你想想躺下来看镜子，你会对这个问题有更清楚的理解。好吧，你的头发仍然在左侧，现在左右变成了上下，而看起来没问题的上下之前却是左右。镜子不知怎么预见到你看着它时会做什么。要对称地描述镜子做了什么——它看起来并不偏斜，然后把左和右弄混了，却没有对上下做同样的事情。经过大量的摸索，逐渐地我知道我们得出了那个答案。你看，如果你挥动这只手，那么镜子里挥动的手正好在相对的位置。东边的手是东边的手，西边的手是西边的手，向上的头是向上的，向下的脚是向下的。一切其实都没问题。但问题出在这里，假设这是北方。你的鼻子在头的后部的北边，但在影像中，鼻子在头的后部的南边。

[段 30]

So what happens really in the image is neither the right nor left mix up with the top and bottom, but the front and back have been reversed, you see. That which is the nose on the thing is on the wrong side of the head, if you want to, all right? Now ordinarily when we think of the image, we think of it as another person. And we think of the normal way that a person would get into that condition over there. It’s a psychological thing. We don’t think of the idea that the person has been squashed and pushed backwards, forwards, with his nose and his head because that’s not what ordinarily happens to people. A person gets to look like he looks in the mirror by walking around and facing you. And because people when they walk around don’t turn their head for their feet, we leave that part alone, but they get their right and left hands swung about, you see, when they turn around, and so we say that it’s left and right interchange, but really the symmetrical way it’s along the axis of the mirror that things get interchanged. Well, that’s kind of an easy one.

[译文 30]

所以影像中真正发生的既不是左右与上下弄混了，而是前后被颠倒了，你明白吗。鼻子所在的那一侧到了头的错误的一侧，如果你愿意这么说的话。通常当我们想到影像时，我们把它想象成另一个人。我们想到的是一个人正常地走到那边变成那个样子。这是一种心理作用。我们不会想到那个人被压扁了、被推着前进后退，鼻子和头换了位置，因为那不是通常发生在人身上的事。一个人走到镜子里看起来那样，是通过走到你面前转身面对你。而当人们转身时，他们不会把头和脚对调，所以我们不管那部分，但他们的左右手在转身时会互换，你看，所以我们说是左右互换，但实际上对称的方式是沿着镜子的轴线发生了互换。嗯，这个算是简单的。

[段 31]

A harder one and very entertaining was what keeps a train on the track? And of course the answer is, as everyone thinks, the flanges on the wheels. You know, the wheels have some kind of flange on them. But that’s not the answer. Those flanges are just safety devices. If the flanges rub against the tracks, you hear a terrible squealing. They’re just in case the real mechanism doesn’t work. There’s another problem with trains that’s connected to it. People all know this about their automobile, that when you go around a corner, the outside wheels have to go further than the inside wheels. And if the front, if the wheels were connected on a solid shaft, you couldn’t do that. You can’t turn the outside wheels further than the inside wheels. And so the shaft is broken in the middle with a gear system, it’s called a differential. Did you ever see the differential on a railroad train? No, you look at those wheels under a freight car, and there are the two wheels, and there’s a solid steel rod going from one wheel to the other. There’s nothing, one turns the same as the other. So now how does it go around the corner, a curve, when the outside wheel has to go further than the inside wheel?

[译文 31]

一个更难的、非常有趣的问题是什么让火车保持在轨道上？当然，答案是，每个人都会说是轮子的轮缘。你知道，轮子上有一种轮缘。但这不是答案。那些轮缘只是安全装置。如果轮缘摩擦轨道，你会听到可怕的尖叫声。它们只是在真正机制失灵时的备用装置。火车还有另一个与之相关的问题。人们都知道自己汽车的情况，当你转弯时，外侧车轮必须比内侧车轮走得更远。如果车轮连接在一根实心轴上，你做不到这一点。你无法让外侧车轮比内侧车轮转得更多。所以轴在中间被一个齿轮系统断开了，这叫做差速器。你见过铁路列车上的差速器吗？没有，你看那些货车下面的车轮，有两个车轮，有一根实心钢棒从一个车轮连接到另一个车轮。什么也没有，一个转多少另一个就转多少。那么当外侧车轮必须比内侧车轮走得更远时，它是怎么转弯的？

[段 32]

And the answer is that the wheels are flanged like this, I mean not flanged, they’re cones this way, that is, they’re a little fatter closer to the train and a little thinner further out. If you look closely, you’ll see they’ve got this beveled edge. And it’s all very simple. When they go around a curve, they slide out on the track a bit, so that this wheel travels on a fatter part, a bigger diameter, and this on a smaller diameter. So when they both turn one turn, this swings further than the other. And that’s what keeps it on the track also, the same way. Suppose a train’s running along on this thing, on the track, and the track’s here and here, and the two wheels are exactly balanced and it’s nice and even. Suppose accidentally it gets a bump or something and slides out this way. Then this wheel is on a bigger circumference than this one, but they’re on a solid shaft. So when it turns once around, it carries this wheel forward, relatively, and steers the train back on the track. Of course, if it gets too far off on the other side, it goes back and forth, and it stays on the track because the wheels are tapered, and the flange is safety.

[译文 32]

答案是轮子像这样是带凸缘的，我的意思不是带凸缘，它们是锥形的，也就是说，靠近火车的地方稍微粗一些，往外的地方稍微细一些。如果你仔细看，你会发现它们有这种斜边。这一切非常简单。当它们转弯时，它们会在轨道上向外滑动一点，所以这个轮子在更粗的部分、更大的直径上行驶，而这个在更小的直径上行驶。所以当它们都转一圈时，这个比那个摆动得更多。它也以同样的方式保持在轨道上。假设火车沿着这个东西行驶，轨道在这里，两个车轮完全平衡，一切平稳。假设它偶然受到碰撞或什么的，向外滑动了一点。那么这个轮的周长比那个大，但它们在一根实心轴上。所以当它转一圈时，它相对地带动这个轮子向前，把火车引导回轨道上。当然，如果它偏离太远到另一边，它会来回摆动，它之所以能保持在轨道上是因为车轮是锥形的，而轮缘是安全装置。

[段 33]

Well, we had a lot of stuff like that that we had to learn, you know, to get straightened out before we could become full-fledged members of the fraternity. If I’m sitting next to a swimming pool, somebody dives in, and she’s not too pretty, so I can think of something else. I think of the waves and things that have formed in the water. And when lots of people have dived in the pool, there’s a very great choppiness of all these waves all over the water. And to think that it’s possible, maybe, that in those waves is a clue as to what’s happening in the pool. That some sort of insect or something with sufficient cleverness could sit in the corner of the pool and just be disturbed by the waves. And by the nature of the irregularities and bumping of the waves, have figured out who jumped in, where and when, and what’s happening all over the pool. And that’s what we’re doing when we’re looking at something. The light that comes out is waves, just like in the swimming pool, except in three dimensions instead of the two dimensions of the pool, as they’re going in all directions.

[译文 33]

嗯，我们有很多类似的东西需要学习，你知道，在成为兄弟会正式成员之前必须先搞清楚这些。如果我坐在游泳池旁边，有人跳入水中，而她长得不太好看，那我就可以想点别的。我想到了水中形成的波纹和各种东西。当很多人跳进游泳池时，水面上就会产生非常剧烈的所有这些波纹的搅动。然后想到，也许在这些波纹中可能包含着关于游泳池里正在发生什么的线索。某种昆虫或什么足够聪明的家伙可以坐在游泳池的角落里，仅仅被波纹所扰动，然后根据波纹的不规则性和碰撞方式，就能推断出谁跳进了水里、在什么地方、什么时候跳的，以及整个游泳池里正在发生什么。这就是我们在观察某个东西时所做的事情。射出的光就像游泳池里的波纹一样，只不过它是在三维空间中传播，而不是游泳池那样的二维，因为它向四面八方传播。

[段 34]

And we have an eighth of an inch black hole into which these things go, which is particularly sensitive to the parts of the waves that are coming in a particular direction. It’s not particularly sensitive when they’re coming in at the wrong angle, which we say is from the corner of our eye. And if we want to get more information in the corner of our mind, we swivel this ball about so that the whole will move from place to place. Then it’s quite wonderful that we can figure out so easy. That’s really because the white waves are easier than the waves in the water, a little bit more complicated. It would have been harder for the bug than for us, but it’s the same idea to figure out what the thing is that we’re looking at at a distance. And this is kind of incredible because when I’m looking at you, someone standing to my left could see somebody who’s standing at my right. That is, the light could be going right across this way. The waves are going this way. The waves are going this way. The waves are going this way. It’s just a complete network.

[译文 34]

而我们有一个八分之一英寸的小黑洞，这些东西会进入其中，它对从特定方向传来的波的某些部分特别敏感。当波从错误的角度传来时，它就不那么敏感了，我们称之为从眼角余光看到的。如果我们想从脑海的角落获取更多信息，我们就转动这个球体，使整个视野从一个地方移动到另一个地方。然后我们就能非常轻松地搞明白这一切，这真的很了不起。这实际上是因为光波比水中的波要容易一些，但也稍微复杂一些。对于那只虫子来说，这比对我们来说要难一些，但搞清楚远处我们正在看的东西是什么，这个想法是一样的。这有点令人难以置信，因为当我在看你的时候，站在我左边的人可能能看到站在我右边的人。也就是说，光可能直接穿过这边。波朝这个方向传播。波朝这个方向传播。波朝这个方向传播。这完全是一个完整的网络。

[段 35]

Now, it’s easy to think of them as arrows passing each other, but that’s not the way it is because all it is is something shaking. It’s called the electric field, but we don’t have to bother with what it is. It’s just like the water height is going up and down. So there’s some quantities shaking about here, and in a combination of motions that’s so elaborate and complicated that that result is to produce an influence which makes me see you, at the same time completely undisturbed by the fact that there are influences that represent the other guy seeing him on this side. So that there’s this tremendous mess of waves all over in space, which we call, which is the light bouncing around the room and going from one thing to the other. Because of course most of the room doesn’t have eighth inch black holes. It’s not interested in that light, but the lights there anyway. I mean, it bounces off this and it bounces off that. Anyway, I mean it bounces off this and it bounces off that, that all this is going on and yet we can sort it out with this instrument.

[译文 35]

现在，很容易把它们想象成互相穿过的箭头，但实际情况并非如此，因为这一切不过是在振动。它叫做电场，但我们不必纠结于它到底是什么。它就像水面高度在上下起伏。所以这里有一些量在振动，以一种极其精密复杂的运动方式组合在一起，最终产生了一种效应，使我能够看到你，同时完全不受另一边那个家伙看到他的影响所干扰。所以空间中有这一大团乱七八糟的波，我们称之为在房间里到处弹来弹去的光，从一样东西传到另一样东西。因为当然，房间里大部分地方并没有八分之一英寸的小黑洞。它对那种光不感兴趣，但光还是在那里。我是说，它从这个弹开，又从那个弹开。总之，我是说它从这个弹开，又从那个弹开，所有这一切都在发生，而我们却能用这个仪器把它们分辨出来。

[段 36]

But beside all that, you see, those waves that I was talking about in the water, maybe they’re so big some of them, and then you could have slower swashes which are longer and shorter. Perhaps our animal who’s making his study is only using waves between this length and that length. So it turns out that the eye is only using waves between this length and that length, except those two lengths are hundred millionths, hundred thousandths of an inch, hundred thousandth of an inch. And what about the slowest swashes, the waves that go more slowly, that have a longer distance from crest to trot? Those represent heat. We feel those, but our eye doesn’t see them focused very well. We don’t, in fact, at all. The shorter waves are blue, and the longer waves are red. But when it gets longer than that, we call it infrared. All this is in there at the same time. That’s the heat. Pit vipers that you’ve got down here in the desert, they have a little thing that they can see the longer waves and pick out mice, which are radiating their heat, their longer waves, by their body heat, by looking at them with this eye, which is the pit of the pit viper.

[译文 36]

但除此之外，你看，我在水中谈到的那些波，也许其中一些非常大，然后你可能有更慢的涌动，有长有短。也许我们那位正在做研究的动物只使用介于这个长度和那个长度之间的波。结果发现，眼睛也只使用介于这个长度和那个长度之间的波，只不过这两个长度是百万分之一英寸、万分之一英寸、十万分之一英寸。而那些最慢的涌动、传播更慢的波，波峰到波谷之间的距离更长。那些代表热量。我们能感觉到它们，但我们的眼睛无法很好地聚焦看到它们。事实上，我们根本看不到。较短的波是蓝色的，较长的波是红色的。但当它比那更长时，我们就称之为红外线。所有这些都同时存在于其中。那就是热量。你们在沙漠里有的响尾蛇，它们有一个小器官，能看到更长的波，找到正在散发热量——它们更长的波——的老鼠，通过体热，用它们的那个眼睛——响尾蛇的颊窝——来观察它们。

[段 37]

But we can’t, we aren’t able to do that. And then these waves get longer and longer, and all through the same space, all these things are going on at the same time, so that in this space there’s not only my vision of you, but information from Moscow radio that’s being broadcast at the present moment, and the singing of somebody from Peru. All the radio waves are just the same kind of waves, only longer waves. And there’s the radar from the airplane, which is looking at the ground to figure out where it is, which is coming through this room at the same time, plus the X-rays, cosmic rays, and all these other things, which are the same kind of waves, exactly the same waves, but shorter, faster, or longer, slower. It’s exactly the same thing. So this big field, this area of irregular motions of this electric field, this vibration, contains this tremendous information, and it’s all really there. That’s what gets you. If you don’t believe it, then you pick a piece of wire and connect it to a box. And in the wire, the electrons will be pushed back and forth by this electric field, sloshing just at the right speed for a certain kind of long ways.

[译文 37]

但我们做不到，我们没有这个能力。然后这些波变得越来越长，在同一个空间里，所有这一切都在同时发生，所以在这个空间里，不仅有我对你的视觉，还有此刻正在播出的莫斯科广播电台的信号，以及来自秘鲁的某人的歌声。所有的无线电波都是同一种波，只是波长更长。还有来自飞机的雷达波，它正在观察地面以确定自己的位置，也同时穿过这个房间，再加上X射线、宇宙射线和所有其他这些东西，它们都是同一种波，完全相同的波，只是更短更快，或者更长更慢。完全是一样的。所以这个大电场区域，这个电场的无规则运动区域，这个振动，包含了巨大的信息，而这一切都真的在那里。这就是让你震撼的地方。如果你不信，那就拿一根电线，把它接到一个盒子上。电线中的电子会被这个电场来回推动，以某种特定长波的恰当速度来回晃动。

[段 38]

And you turn some knobs on the box to get the sloshing just right, and you hear Radio Moscow. You know that it was there. How else did it get there? It was there all the time. It’s only when you turn on the radio that you notice it. But then all these things are going through the room at the same time, which everybody knows. But you’ve got to stop and think about it to really get the pleasure about the complexity, the inconceivable nature of nature. When we were talking about the atoms, one of the troubles that people have with the atoms is that they’re so tiny, and it’s so hard to imagine the scale, that the size of the atoms are in size compared to an apple, it’s the same scale as an apple is to the size of the Earth. And that’s a kind of a hard thing to take, and you have to go through all these things all the time, and people find these numbers inconceivable, and I do too, and the only thing you do is you just change your scale. I mean, you’re just thinking of small balls, but you don’t try to think of exactly how small they are too often, or you get kind of a bit nutty.

[译文 38]

然后你转动盒子上的旋钮，把晃动的频率调得恰到好处，你就听到了莫斯科广播电台。你知道它一直在那里。不然它怎么会在那里的？它一直都在那里。只是当你打开收音机时你才注意到它。但所有这些东西同时穿过房间，这是大家都知道的。但你得停下来好好想想，才能真正体会到这种复杂性，大自然的不可思议之处。当我们谈论原子时，人们对原子的困扰之一就是它们太小了，很难想象那个比例——原子的大小与苹果的比例，就像苹果的大小与地球的比例一样。这有点让人难以接受，而且你不得不一直面对这些，人们觉得这些数字不可思议，我也觉得，你唯一能做的就是改变你的尺度。我是说你只是把它们想象成小球，但不要试图去精确地想它们到底有多小，否则你会变得有点疯疯癫癫的。

[段 39]

All right, but in astronomy you have the same thing in reverse because the distances to these stars are so enormous. You know that light goes so fast that it takes a few seconds to go to the moon and back, or it goes around the earth seven and a half times in a second. And it goes for a year, two years, three years before it gets to the nearest other star that there is to us. But all our stars are in the stars that are nearby in a great galaxy, a big mass of stars, which is called a galaxy, a group. But this galaxy is, what is it, something a hundred thousand light years, like a hundred thousand years, and then there’s another patch of stars. It takes a million years for the light to get here, going at this enormous rate. And you just go crazy trying to make too real that distance. You have to do everything in proportion. It’s easy to save the galaxies, the little patches of stars, and they’re ten times as far apart as they are big. So that’s an easy picture. It only gets it. But you just go to a different scale.

[译文 39]

好吧，但在天文学中情况正好相反，因为这些恒星的距离是如此之远。你知道光传播得如此之快，以至于往返月球只需要几秒钟，或者在一秒内绕地球七圈半。而光需要一年、两年、三年才能到达离我们最近的另一颗恒星。但所有的恒星都在我们附近的一个巨大星系中，一大团恒星，叫做星系，一个群体。但这个星系，它是什么来着，大约十万光年，就像十万年的距离，然后还有一片恒星。光以这个巨大的速度传播，需要一百万年才能到达这里。你试图把这些距离想象得太真实，简直要发疯。你必须按比例来处理一切。很容易把星系想象成小片恒星，它们之间的距离是自身大小的十倍。这样画面就容易理解了。它只能理解到这里。你只是换了一个不同的尺度。

[段 40]

That’s easier. Once in a while you try to come back to Earth’s scale to discuss the galaxies. But it’s kind of hard. The number of stars that we see at night is only about 5,000. But the number of stars in our galaxy, the telescopes have shown when you improve the instrument, oh, we look at a galaxy, we look at the stars, all the light that we see, the little tiny influence, spreads from the star over this enormous distance of three light years from the nearest star. On, on, on, this light from the star is spreading. The wave fronts are getting wider and wider, weaker and weaker, weaker and weaker out into all of space, and finally the tiny fraction of it comes in one square, weight of an inch, tiny little black hole, and does something to me so I know it’s there. Well, to know a little bit more about it, I’d rather gather a little more of this little, this tiny fraction of this front of light. And so I make a big telescope, which is a kind of funnel, that the light that comes over this big area, 200 inches across, is very carefully organized so it’s all concentrated back so it can go through a pupil, actually.

[译文 40]

这样更容易。偶尔你会试图回到地球的尺度来讨论星系。但这有点难。我们在夜晚看到的恒星数量大约只有五千颗。但我们星系中的恒星数量，当望远镜改进了仪器，哦，我们观察一个星系，我们观察恒星，我们看到的所有光，那种微小的影响，从恒星传播开来，跨越了巨大的距离——离最近的恒星三光年。不断地，不断地，恒星的光在扩散。波前越来越宽，越来越弱，越来越弱，扩散到整个空间中，最终极微小的一部分进入一平方英寸的小小黑洞，产生某种作用，让我知道它的存在。那么，为了多了解它一点，我宁愿多收集一点这束光波前的极微小的一部分。于是我造了一个大望远镜，它就像一个漏斗，从大片区域——200英寸宽——传来的光被非常精细地组织起来，全部重新汇聚，以便真正通过瞳孔。

[段 41]

It’s better to photograph it. Or nowadays, they use photocells. They’re a better instrument. But anyway, the idea of the telescope is to focus the light from a bigger area into a smaller area so that we see things that are weaker, less light. And in that way we find there’s a very large number of stars in the galaxy. There’s so many that if you tried to name them, one a second, naming all the stars in our galaxy – I don’t mean all the stars in the universe, just this galaxy here – it takes 3,000 years. And yet that’s not a very big number because if those stars were to drop one dollar bill on the Earth during a year, each star dropping one dollar bill, they might take care of the deficit which is suggested for the budget of the United States. We’ll see what kind of numbers we have to deal with. At any rate, I think that the numbers are a problem in astronomy, the sizes and numbers. And the best thing to do is to relax and enjoy the tininess of us and the enormity of the rest of the universe. Of course, if you’re feeling depressed by that, you can always look at it the other way and think of how big you are compared to the atoms and the parts of atoms, and then you’re an enormous universe through those atoms.

[译文 41]

最好还是用照片把它拍下来。或者现在人们用的是光电管，那是更好的仪器。但无论如何，望远镜的原理就是把更大区域的光聚焦到更小的区域，这样我们就能看到更暗、光更弱的东西。通过这种方式我们发现银河系中有非常多的星星。星星的数量太多了，如果你试图每秒钟给它们命名一个，把我们银河系里所有的星星都命名——我说的不是宇宙中所有的星星，仅仅是这个银河系——那需要花上3000年。然而这个数字还不算大，因为如果那些星星每年往地球上扔一张美元钞票，每颗星星扔一张，它们或许就能弥补美国预算中提出的赤字。我们来看看我们要面对的是什么样的数字。不管怎样，我认为在天文学中，数字和尺度是一个问题。最好的做法就是放松下来，享受我们自身的渺小和宇宙其余部分的浩瀚。当然，如果你因此感到沮丧，你总可以换个角度想想，想想你比起原子和原子内部的微粒有多么庞大，那么你就是那些原子构成的一个巨大宇宙。

[段 42]

So you can sort of stand in the middle and enjoy everything both ways. But the real, the great part of astronomy is the imagination that’s been necessary to guess what kinds of structures, what kinds of things can be happening to produce the light and the effects of the light of the stars that we do see. And I could take an example, a historical example. See, many times in science, by using imagination, you’ve imagined something which could be, according to all the known knowledge of the laws, and you don’t know whether it is yet or not. And that’s very interesting. There’s a creative imagination, you like to call it, not just imagining things that are relatively easy, but something different. And to take an example of a star, as we understand it, an ordinary star like the Sun is a great big ball of gas, of hydrogen. It’s burning up the hydrogen and so forth, and it’s an enormous mass of gas. And it’s held together by gravity. You don’t have to always understand gravity as curved space. It’s good enough for this purpose that force inversely is square of the distance. When things are closer together, the force is stronger, and it pulls everything together.

[译文 42]

所以你可以站在中间，两个方向都享受一下。但天文学真正伟大之处在于想象力——需要想象力去猜测可能存在什么样的结构、什么样的事件，才能产生我们所观察到的恒星的光和光的效应。我可以举一个历史上的例子。你看，在科学中很多时候，通过想象力，你想象了某种可能存在的东西，根据所有已知的物理定律它可能存在，但你还不确定它是否真的存在。这非常有趣。这是一种创造性的想象力，你可以这么叫，不只是想象那些相对容易想象的东西，而是想象不一样的东西。举一个恒星的例子，按照我们的理解，一颗普通的恒星，比如太阳，是一个巨大的氢气球。它在燃烧氢等等，它是一个巨大的气体球。它靠引力聚在一起。你不必总是把引力理解为弯曲的空间。在这个用途上，引力与距离的平方成反比就够了。物体越近，引力就越强，它把所有东西拉在一起。

[段 43]

By the way, that’s why the world is round, because the globe of Earth is pulled together as much as possible, and if it had a great mountain and an irregularity of a bump, so it would be pulled in by gravity, and it all gets smooth. Rocks aren’t strong enough to hold a bump much bigger than a few miles, and Mount Everest is our biggest bump, but on the moon where the gravity is less, the bumps are higher, the mountains are bigger on the moon. Anyway, to get back to the star, it’s all held together by gravity, and it’s got a nuclear fuel which we’ve not, haven’t been talking about, that’s burning up the hydrogen and generating energy, which keeps things going. And after a while, I would use the fuel up. People began to think about what would happen then. And it would be possible to just be gas sort of hanging around, held together by gravity, but quiet. But another possibility was to think, if I push the stuff together closer, the gravity is stronger. Would it hold together? Well, if you push a little bit together, the pressure increases. When you push gas together, there are more atoms and they pound harder, so the pressure is higher, but the gravity stronger, and it turns out the pressure wins, so it would just come out again.

[译文 43]

顺便说一下，这就是为什么地球是圆的，因为地球球体被尽可能地拉在一起，如果有一座大山或者一个不规则的凸起，它就会被引力拉进去，一切就变得光滑了。岩石不够坚硬，无法支撑超过几英里的凸起，珠穆朗玛峰就是我们最大的凸起，但在月球上引力较小，凸起就更高，月球上的山脉更大。总之，回到恒星，它完全靠引力聚在一起，它有核燃料，我们还没谈到过，它在燃烧氢并产生能量，维持一切运转。过一段时间，燃料就会用完。人们开始思考那之后会发生什么。一种可能只是气体靠引力聚在一起，但很安静。但另一种可能性是，如果我把物质压得更紧，引力就会更强。它还能聚在一起吗？嗯，如果你稍微压紧一点，压力就会增大。当你压缩气体时，原子更多了，它们撞击更猛烈，所以压力更高，但引力也更强，结果发现压力赢了，所以气体又会散开。

[段 44]

If you’re pushing a star and like that, it oscillates, and there are some stars that are oscillating and vibrating and so on. But then, but it turns out if you keep on analyzing and you push it together very far, to the incredible concentration that the whole mass of the Sun is down to the size of the Earth or smaller, then it turns to all the nuclear matter, all the nuclei of the atoms are all stuck next to each other tight, the electrons are in spaces where the electrons are, and it’s all squashed out, and it comes out, that when you get to that far, the gravity is strong enough, has overpowered the pressure again, even though the pressure’s got to be enormous, the gravity’s got to be even more enormous, and the thing will stay steady at a different size, and be nothing but a neutron’s nuclear matter, nothing, solid nuclear matter. And this is a possibility that was worked out by Oppenheimer and Volkoff, and it’s called a neutron star. And people waited to see if there were any such neutron stars for years, until recently they found these strange pulsars which emit flashes of radio waves, and later they found light which can go 30 times a second, for instance the fastest ones, or maybe 10 times a second or one a second.

[译文 44]

如果你像那样压缩一颗恒星，它就会振荡，确实有一些恒星在振荡和振动等等。但是，如果你继续分析，把它压缩到难以置信的密度——整个太阳的质量压缩到地球那么大或更小——那么它就变成了所有的原子核物质，所有原子核都紧紧地挤在一起，电子在电子所在的空间里，一切都被压扁了，结果发现，当你压缩到那种程度时，引力足够强大，再次压倒了压力，尽管压力已经极其巨大，引力更加巨大，天体会稳定在不同的大小上，完全变成中子的核物质，纯粹的固体核物质。这是奥本海默和沃尔科夫提出的一种可能性，叫做中子星。人们等了很多年想看看有没有这样的中子星，直到最近他们发现了这些奇怪的脉冲星，它们发射无线电波闪光，后来他们发现光每秒可以闪30次，比如最快的那些，或者每秒10次或每秒1次。

[段 45]

And at first that’s very mysterious. You’re used to stars being big and slow, and how can anything in a star move in a 30th of a second? Well, these things are very small neutron stars, and they’re spinning very fast. And there’s some, for reasons not yet understood, they’re emitting a beam of radio waves like a searchlight in an airport or something, and those things go around. Boop, boop, boop. So we get the flashes. Tick, tick, tick, tick, tick, tick, tick, tick, tick. That fast. To imagine a star the mass of the Sun doing something, turning so fast as 30 times a second, is another one of these big number hard to conceive imaginary things, okay? And the whole idea that there could be a star of such enormous density that a teaspoon would weigh so much of the matter that if you put it down on the Earth’s surface, it’s so heavy it’ll just plow right through to the center of the Earth, and things like that. It took a lot of imagination. It comes out of the mathematics and the analysis and all this that helped you to make sure you’re not making a mistake.

[译文 45]

一开始这非常神秘。你已经习惯了恒星又大又慢，恒星中的什么东西怎么可能在三十分之一秒内运动？嗯，这些是非常小的中子星，它们旋转得非常快。由于某些尚未理解的原因，它们像机场的探照灯一样发射无线电波束，这些东西在转。噗、噗、噗。所以我们接收到闪光。嘀、嘀、嘀、嘀、嘀、嘀、嘀、嘀、嘀。那么快。想象一颗质量相当于太阳的恒星每秒旋转30次，这是另一个难以想象的巨大数字，好吗？整个概念是可能存在一颗密度如此之大的恒星，一茶匙的物质重到如果放在地球表面，它会直接钻到地心，诸如此类的事情。这需要大量的想象力。它来自数学和分析，以及所有那些帮助你确保自己不出错的东西。

[段 46]

And it turns out that such a star was possible, and it turned out later in fact they do exist. And that’s a good example of how imagination is a useful thing and produces a guessing ahead of time, and how we make advances by using it. Beside just the very difficult thing of imagining all the things that might be up there to explain the things we see. In the case of astronomy, we have a large number of things that we see that we have not yet quite clearly got the imagination to see what it is that’s producing them. Quasars are very powerful sources of light and radio waves from very great distances. We can see them because they’re so bright. The exact cause of their sources is only gradually being recently understood in terms of another nutty concept of imagination, the black hole, which is something that comes from following the logic of the gravity theory of Einstein to its ultimate, working out the consequences in crazy circumstances. Suppose you had an amount of matter so great that the gravity forces so much that even light trying to get out falls back. Nothing can go faster than light, and nothing could escape.

[译文 46]

结果证明这样的恒星是可能的，后来事实证明它们确实存在。这是一个很好的例子，说明想象力是有用的东西，能够提前做出猜测，以及我们如何通过想象力取得进展。除了想象那里可能存在的一切东西来解释我们所看到的事物这个非常困难的任务之外。在天文学中，我们有很多看到的东西，我们还没有足够的想象力去想象是什么在产生它们。类星体是非常强大的光和无线电波来源，来自非常遥远的距离。我们能看到它们是因为它们非常亮。它们的确切成因直到最近才逐渐被理解，用另一个疯狂的想象概念来说，就是黑洞，它来自把爱因斯坦的引力理论按照其逻辑推向极致，在极端情况下推导出其后果。假设你有一团物质，质量极大，引力极强，以至于连试图逃逸的光都会掉回去。没有什么比光更快，没有什么能逃出去。

[段 47]

You couldn’t see it. How would you get there? If you had a lot of matter to start with, it could fall together and get into this condition that no longer could the light come out. So you would have this thing which would continue to attract things to it. Things would go in and nothing would come out. That’s called the black hole. And you say, well, how can a black hole, which is absorbing everything, make all this energy that we see? Is that an explanation of the quasar? Actually, it may well be, because if the things are falling in, don’t go plonk in, but go around, falling in by swirling, then as they fall in, and irregularly and so forth, and in the fast motions that it produces, they go down this whirlpool, they generate a lot of energy and friction and so forth, and different kinds of effects, magnetic and electric effects, that could make the jets of matter that come out of the quasar and the radio galaxies in ways that are not really understood. We don’t have a real picture of why there are jets of radio waves and so matter emitting radio waves in galaxies.

[译文 47]

你看不到它。你怎么到达那里呢？如果你一开始就有大量物质，它可能坍缩到一起，进入光再也无法逃逸的状态。于是你就有了一个不断吸引东西的天体。东西进去，但没有什么出来。这叫做黑洞。你会说，嗯，一个黑洞在吸收所有东西，它怎么能产生我们看到的所有这些能量？这是类星体的解释吗？实际上，很可能是，因为如果东西掉进去，不是直接掉进去，而是旋转着螺旋式掉进去，那么在掉进去的过程中，由于不规则等等，在它产生的快速运动中，它们沿着这个漩涡下去，产生大量能量和摩擦等等，以及各种效应，磁效应和电效应，这可能产生类星体和射电星系中喷射出的物质喷流，尽管方式还不完全理解。我们还没有一个真正的图像来解释为什么星系中有无线电波喷流和发射无线电波的物质。

[段 48]

There are galaxies which great jets have come out of, big clouds of matter on each side which are emitting radio waves. So there’s some kind of a source in there that sort of gets wound up and then shoots these jets of material out with tremendous energy, and it’s guessed that maybe that’s a black hole somehow or other. And the somehow or other is the challenge of imagination which has not yet been answered by anybody with any great confidence. You ask me if an ordinary person, by studying hard, would get to be able to imagine these things like I imagine. Of course, I was an ordinary person who studied hard. There’s no miracle people. It just happens they got interested in this thing and they learned all this stuff. They’re just people. There’s no talent, a special miracle ability to understand quantum mechanics or a miracle ability to imagine electromagnetic fields that comes without practice and reading and learning and study. So if you say you take an ordinary person who’s willing to devote a great deal of time and study and work and thinking and mathematics and time and time, then he’s become a scientist.

[译文 48]

有些星系从中喷射出巨大的喷流，两侧有大片物质云在发射无线电波。所以里面一定有某种东西，它不知怎么被激发，然后以巨大的能量把这些物质喷流射出去，人们猜测也许那不知怎么的是一个黑洞。而"不知怎么"正是想象力的挑战，还没有任何人带着充分的信心回答这个问题。你问我，一个普通人通过努力学习，能不能像我一样想象这些东西。当然，我就是一个通过努力学习的普通人。没有什么奇迹般的人。他们只是对这东西感兴趣，然后学会了所有这些知识。他们就是普通人。没有什么天赋，没有什么不经过练习、阅读、学习和研究就能理解量子力学或想象电磁场的特殊奇迹能力。所以如果你说一个普通人愿意投入大量的时间、学习、工作、思考、数学和时间，那么他就成为了一个科学家。

[段 49]

When I’m actually doing my own things and I’m working in the high, you know, deep and esoteric stuff that I worry about, I don’t think I can describe very well what it’s like. First of all, it’s like asking a centipede which leg comes after which. It happens quickly, and I’m not exactly sure what flashes and stuff go in the head. But I know it’s a crazy mixture of partially equations, partial solving the equation, then having some sort of picture of what’s happening that the equation is saying is happening, but they’re not that well separated as the words I’m using. And it’s a kind of a nutty thing. It’s very hard to describe, and I don’t know that it does any good to describe it. And that is something that struck me that’s very curious. I suspect that what goes on in every man’s head might be very, very different, the actual imagery or semi-imagery which comes, and that when we’re talking to each other at these high and complicated levels, and we think we’re speaking very well and we’re communicating, but what we’re really doing is having some kind of big translation scheme going on for translating what this fellow says into our images, which are very different.

[译文 49]

当我在做自己的事情，研究那些高深、晦涩的领域时，我觉得自己很难描述那种体验究竟是什么样的。首先，这就像问一条蜈蚣哪条腿跟在哪条腿后面一样。一切发生得很快，我也不太清楚脑海中闪过的是什么、发生了什么。但我知道那是一种疯狂的混合体——部分是方程，部分是解方程的过程，然后产生某种关于正在发生什么的图像——也就是方程所描述的那个画面——但它们并不像我使用的语言那样彼此分明。这真是一种疯狂的东西。很难描述，我也不知道描述它有什么好处。这让我觉得非常好奇。我怀疑每个人头脑中实际发生的图像或半图像可能非常、非常不同，而当我们以这些高深复杂的层面彼此交谈时，我们以为自己说得很清楚、沟通得很好，但实际情况是，我们的大脑一直在进行某种庞大的翻译过程——把对方说的话翻译成我们各自非常不同的内心图像。

[段 50]

I found that out because at the very lowest level, I won’t go into the details, but I got interested in, well, I was doing some experiments and I was trying to figure out something about our time sense. And so what I would do is I would count, trying to count to a minute. Actually, say I’d count to 48, and it would be one minute. So I’d calibrate myself, and I would count a minute and 48, think I was counting seconds, but it’s close enough. And then it turns out if you repeat that, you can do very accurately. When you get to 48 or 47 or 49, not far off, you’re very close to a minute. And I would try to find out what affected that time sense, and whether I could do anything at the same time as I was counting. And I found that I could do many things. I could… There were some things that not. For example, I had great difficulty. I was in the university. I had to get my laundry ready, and I was putting the socks out, and I had to make a list how many socks. And it was something like six or eight socks, and I couldn’t count them because the counting machine was being used, and I couldn’t count them until I found that I could put them in a pattern and recognizing the number.

[译文 50]

我之所以发现这一点，是因为在最基础的层面上——我就不细说了——我对一些事情产生了兴趣，当时我在做实验，试图弄清我们时间感知的某些特征。我的做法是数数，试着数到一分钟。实际上，我数到48大概就是一分钟。所以我先给自己校准一下，数一分钟就是48，我本以为自己在数秒，但也差不多了。结果发现，如果你反复这样做，可以非常准确地做到。当你数到48、47或49时，误差不大，非常接近一分钟。然后我想找出是什么影响了这种时间感知，以及我在数数的同时是否还能做其他事情。我发现我可以做很多事。有些事不行。比如，我遇到了很大的困难。当时我在大学里，要整理衣物，我把袜子摆出来，需要列个清单看有多少只。大概有六到八只袜子，但我数不出来，因为那个"计数机器"正在运转，直到我发现可以把它们摆成某种图案，通过识别图案来知道数量。

[段 51]

And so I learned a way after practicing by which I could go down the lines of type in newspapers and see them in groups, 3-3-3-1, that’s a group of 10, 3-3-3-1, without saying the numbers, just seeing the groupings. I could therefore count the lines of type I practiced in the newspaper at the same time I was counting internally the seconds. And so I would come, I could do this fantastic trick of saying, 48, that’s one minute, and there are 67 lines of type, you see. It was quite wonderful. And I discovered many things I could read while I was… No, excuse me. Yes. Yes, I could read perfectly all right while I was counting and get an idea of what it was about. But I couldn’t speak, I couldn’t say anything. Because, of course, when I count, I sort of spoke to myself inside. I would say one, two, three sort of in the head. Well, I went down to the breakfast, and there was a junk two, and there was John Tukey, was a mathematician down at Princeton at the same time, and we had many discussions, and I was telling him about these experiments and what I could do, and he says that’s absurd, he says, I don’t see why you would have any difficulty talking whatsoever, and I can’t possibly believe that you could read.

[译文 51]

于是我学会了一种方法，经过练习后，我可以沿着报纸的版面逐行看，把它们看成一组一组的，3-3-3-1，那就是10，3-3-3-1，不用说数字，直接看出分组。因此我可以在内心数秒的同时，数出报纸上我练习过的那版面的行数。于是我就能耍这个奇妙的把戏：数到48，就是一分钟，然后说一共有67行字，你看。这真是棒极了。我发现了很多事情可以在……不，抱歉。是的。是的，我在数数的同时完全可以阅读，并且能理解内容。但我不能说话，什么都说不出来。因为，当然啦，当我数数时，我会在心里默默地对自己说。我会在心里说一、二、三之类的。后来我去吃早餐，约翰·图基也在那里，他是当时普林斯顿的一位数学家，我们经常讨论。我告诉他这些实验和我能做到的事情，他说这太荒谬了，他说我不明白你说话怎么会有任何困难，而且我根本不相信你能阅读。

[段 52]

So I couldn’t believe all this, but we calibrated him. It was 52 for him to get to 60 seconds, or whatever, I don’t remember the numbers now, and then he’d say, all right, he said, what do you want me to say, Mary had a little lamb, I can speak about anything, blah blah blah blah blah, 52, it’s a minute. And he was right, and I couldn’t possibly do that. And he wanted me to read because he couldn’t believe it, and then we compared notes, and it turned out that when he thought of counting, what he did inside his head when he counted was he saw a tape with numbers that when clink clink clink the tape would change with the numbers printed on it. He could see. Well, since it’s sort of an optical system that he’s using and not voice, he could speak as much as he wanted, but if he had to read, then he couldn’t look at his clock. Whereas for me it was the other way, and that’s where I discovered, at least in this very simple operation of counting, the great difference in what goes on in the head when people think they’re doing the same thing.

[译文 52]

我简直不敢相信这些，但我们给他做了校准。他数到52就是60秒，或者别的什么数字，我现在记不清了，然后他说，好吧，你想让我说什么？“玛丽有只小羊羔”，我可以随便说什么，吧啦吧啦吧啦，52，一分钟到了。他说得对，而我根本做不到。他想让我读东西，因为他不敢相信，然后我们交流了各自的发现，结果发现，当他想到数数时，他内心在数数时看到的是一条印有数字的纸带，当咔嗒咔嗒咔嗒时，纸带上的数字会变化。他能看到。由于他使用的是某种视觉系统而不是声音系统，所以他想怎么说都行，但如果他需要阅读，那就没法看他的"时钟"了。而对我来说恰好相反，正是在这个非常简单的数数操作中，我发现了当人们以为自己在做同样的事情时，头脑中发生的事情有多么不同。

[段 53]

And so it struck me, therefore, if that’s already true at the most elementary level, when we learn the mathematics and the Bessel functions and the exponentials and the electric fields and all these things, that the imageries and method by which we’re storing it all and the way we think about it could be really, if we could get it through each other’s heads, entirely different. And in fact, why somebody sometimes has a great deal of difficulty understanding a point which you see as obvious, and vice versa, it may be because it’s a little hard to translate what you just said into his particular framework and so on. Now I’m talking like a psychologist, and you know I know nothing about this. Suppose that little things behaved very differently than anything that was big, anything that you’re familiar with. Because you see, as the animal evolves and so on, as the brain evolves, it gets used to handling, and the brain is designed for ordinary circumstances. But if the gut particles and the deep inner workings were by some other rules and some other character, they behaved differently, they were very different than anything on a large scale, then there would be some kind of difficulty in understanding and imagining reality.

[译文 53]

因此这让我意识到，如果最基础的层面已经如此，那么当我们学习数学、贝塞尔函数、指数函数、电场以及所有这些东西时，我们存储信息和思考方式所用的图像和方法，如果我们能看透彼此的大脑，可能会完全不同。事实上，为什么有时候某人很难理解一个在你看来显而易见的观点，反之亦然，可能就是因为把你刚才说的话翻译成他特定的思维框架有些困难。现在我说起话来像个心理学家，你知道我对这方面一无所知。假设微小的东西的行为与你所熟悉的任何大尺度东西的行为非常不同。因为你知道，随着动物的进化等等，随着大脑的进化，它变得习惯于处理日常事务，大脑是为普通情况而设计的。但如果微观粒子和深层机制遵循的是另一种规则、另一种特性，它们的行为与大尺度上的任何东西都截然不同，那么理解和想象现实就会遇到某种困难。

[段 54]

And that difficulty we are in. The behavior of things on a small scale is so fantastic, it’s so wonderfully different, so marvelously different than anything that behaves on a large scale. You say, electrons act like waves. No, they don’t exactly. They act like particles. No, they don’t exactly. They act like a kind of a fog around the nucleus. No, they don’t exactly. And if you would like to get a clear, sharp picture of an atom so that you can tell exactly how it’s going to behave correctly, have a good image, in other words, a really good image of reality, I don’t know how to do it. Because that image has to be mathematical. We have a mathematical expression. Strange, it’s mathematics. I don’t understand how it is. But we can write mathematical expressions and calculate what the thing is going to do without actually being able to picture it. It would be something like a computer that you put certain numbers in, and you have the formula for at what time the car will arrive at different destinations, and the thing does the arithmetic to figure out what time the car arrives at the different destinations, but cannot picture the car.

[译文 54]

而我们正处于这种困难之中。微观事物的行为如此奇妙，与大尺度事物的行为如此美妙地不同、奇妙地不同。你说电子表现得像波。不，不完全是。它们表现得像粒子。不，不完全是。它们表现得像原子核周围的某种雾。不，不完全是。如果你想获得一个清晰、准确的原子图像，以便正确预测它的行为，换句话说，就是获得一个真正好的现实图像，我不知道该怎么做。因为那个图像必须是数学的。我们有一个数学表达式。很奇怪，是数学。我不理解这是怎么回事。但我们可以写出数学表达式来计算事物的行为，却无法真正想象出它的样子。它就像一台计算机，你输入某些数字，它有公式可以计算汽车在不同时间到达不同目的地，这台机器通过运算算出汽车到达各目的地的时间，但无法想象汽车的样子。

[段 55]

It’s just doing the arithmetic. So we know how to do the arithmetic, but we cannot picture the car. It’s not 100% because for certain situations a certain kind of approximate picture works, that it’s simply a fog around the nucleus that when you squeeze it, it repels you, is very good for understanding the stiffness of material, that it’s a wave which does this and that is very good for some other phenomenon. So when you’re working with certain particular aspects of the behavior of atoms, for instance, when I was talking about temperature and so forth, that they’re just little balls is good enough, and it gives a very nice picture of temperature. But if you ask more specific questions and you get down to questions like, how is it that when you cool helium down, even to absolute zero where there’s not supposed to be any motion, it’s a perfect fluid that hasn’t any viscosity, has no resistance, flows perfectly, and isn’t freezing? Well, if you want to get a picture of atoms that has all of that in it, I can’t do it, you see. But I can explain why the helium behaves as it does by taking my equations and showing that consequences of them is that the helium will behave as it is observed to behave.

[译文 55]

它只是在运算。所以我们会运算，但无法想象汽车的样子。这也不是百分之百的，因为对于某些情况，某种近似的图像是有效的——比如原子核周围的某种雾，当你挤压它时它会排斥你，这非常适合理解物质的刚性；而它是一种波，做这做那，又非常适合解释其他某些现象。所以当你研究原子行为的某些特定方面时，比如我刚才谈到的温度等等，把它们看作小球就足够了，它能很好地描述温度。但如果你问更具体的问题，深入到比如：氦气被冷却时，即使冷却到绝对零度——按理说不应该有任何运动——它却是一种完美的流体，没有黏度，没有阻力，完美地流动，而且不凝固？好吧，如果你想获得一个能包含所有这些性质的原子图像，我做不到，你看。但我可以通过我的方程来解释氦气为什么会这样行为，并展示方程的推论与氦气的实际观测行为一致。

[段 56]

So we know we have the theory right, but we haven’t got the pictures that will go with the theory. And is that because we’re limited and haven’t caught on to the right pictures? Or is that because there aren’t any right pictures for people who have to make pictures out of things that are familiar to them? Well, let’s suppose it’s the last one, but there’s no right pictures in terms of things that are familiar to them. Is it possible then to develop a familiarity with those things that are not familiar on hand, by study, by learning about the properties of atoms and quantum mechanics, by practicing with the equations until it becomes a kind of second nature, just like it’s second nature to know that if two balls came toward each other, they’d smash into bits. You don’t say the two balls when they come toward each other turn blue. You know what they do. So the question is whether you could get to know what things do better than we do today. As the generations develop, will they invent ways of teaching so that the new people will learn the tricky ways of looking at things and be so trained, so well trained, that they won’t have our troubles with the atom picturing.

[译文 56]

所以我们的理论是对的，但我们还没有与理论相匹配的图像。这是因为我们有限制，还没有找到正确的图像？还是因为对于必须从熟悉事物中构建图像的人来说，根本就不存在正确的图像？让我们假设是后者，但确实不存在基于熟悉事物的正确图像。那么有没有可能通过研究、通过学习原子和量子力学的性质、通过反复练习方程直到它成为一种第二天性来培养对不熟悉事物的熟悉感——就像知道两个球相撞时会碎成碎片是第二天性一样。你不会说两个球相向而行时会变成蓝色。你知道它们会怎样。所以问题在于，我们是否能比现在更好地了解事物的行为方式。随着一代代人的发展，他们是否会发明新的教学方法，使新人学会看待事物的巧妙方式，训练得如此出色、如此熟练，以至于他们不会像我们现在这样在想象原子时遇到困难。

[段 57]

There’s still a school of thought that cannot believe that the atomic behavior is so different than large-scale behavior. I think that’s a deep prejudice. It’s a prejudice from being so used to large-scale behavior. And they’re always seeking to find, to waiting for the day that we discover that underneath the quantum mechanics there’s some mundane, ordinary balls hitting or particles moving and so on. I think they’re going to be defeated. I think nature’s imagination is so much greater than man’s, she’s never going to let us relax. Thank you.

[译文 57]

仍有一派学者无法相信原子层面的行为竟与宏观层面的行为如此不同。我认为这是一种根深蒂固的偏见。这种偏见源于我们对宏观行为太过习以为常。他们一直在寻找，一直在等待有一天我们发现量子力学背后不过是一些寻常的、普通的球体碰撞或粒子运动之类的。我认为他们终将失败。大自然的想象力远胜人类，她绝不会让我们安于现状。谢谢。