Narrator: Listen to part of a discussion in a history of science class. The class is discussing the heliocentric theory.

旁白：请听一段科学史课上的部分讨论。这门课正在讨论日心说。

Male student: What I find really difficult to understand is why the heliocentric theory… Um, why it wasn't, like, believed by everybody right away.

男学生：我觉得难以理解的是为什么日心说……嗯，为什么人们并不是立刻就相信它。

Male professor: Well, one thing that's hard to do is to sort of see things from the perspective of someone who's hearing that theory for the first time.

男教授：嗯，很难做的一件事情就是从第一次听说这个理论的人的视角看问题。

I mean today we tend to assume that the moment the heliocentric theory was laid out,

我的意思是现在让我们试着假设，刚提出日心说的时候，

the idea that the Sun, not the Earth, was the center of the solar system, that, you know, you'd have to be in denial not to accept it.

即认为太阳，而不是地球，才是太阳系的中心，你们就必须否定这个观点而不去接受它。

But it really wasn't that easy.

但是这真的不是件容易的事情。

Male student: But the idea that the Earth wasn't the center of the universe… that had been tossed around for, like centuries, right?

男学生：但是地球并不是宇宙中心的这个观点……这个观点已经盛行了好几个世纪了，对吗？

I mean, lots of people had had the idea.

我的意思是，很多人都有过这样的想法。

Male professor: Yes, that's true, going all the way back to the ancient Greeks.

男教授：是的，是真的，一直可以追溯到古希腊时代。

But in Europe when Galileo championed it in the seventeenth century, due in part to his discoveries using a telescope, there still was some major resistance to it.

但是在欧洲，伽利略在17世纪支持日心说，但部分原因是因为他使用望远镜进行观察，还是有很多反对的声音的。

Male student: But I still don't understand why. I mean, isn't it obvious?

男学生：但是我还是不理解为什么，我的意思是，这（太阳是太阳系的中心）不是很明显的事吗？

Male professor: Well…, despite Galileo's ingenious arguments in support of the heliocentric theory, there were still a lot of reasons why people of that period couldn't buy into it.

男教授：嗯……尽管伽利略为支持日心说进行了富有独创性的论证，但那个时代的人们仍有许多理由不相信它。

Remember, we're talking about 400 years ago. So, uh, let's think about a few of those reasons, OK?

你们要记得，我们在谈论四百年前的人。所以呢，我们来看看这些原因都是什么吧，好吗？

So, first of all, they could work out that if the Earth was going around the Sun, then it had to be traveling at many thousands of kilometers per hour.

所以，首先，他们可以计算出如果地球绕着太阳转，那么它必须以每小时数千公里的速度运动。

And that was just beyond anything anyone could understand. You know, they could understand riding a horse or walking.

这个是超出任何人的理解范围的。你要知道，他们可以理解骑马或者步行。

Maybe they could get up to 30, 32 kilometers per hour, but tens of thousands of kilometers per hour?

也许它们可以达到一小时30或32公里的速度，但是一小时几万公里？

That was just crazy. So, to many people, whatever's going on, it couldn't be that.

这就是很疯狂的了。所以很多人无论如何是不能理解这个速度的。

Female student: Hmm. So people didn't believe the heliocentric theory… because it was so hard to believe?

女学生：嗯。所以人们不相信日心说……是因为日心说很难被人相信？

Male professor: Exactly. But there were more scientific kinds of reactions as well.

男教授：是的。但是也有更加具有科学性的回应。

Cause, look, if you've ever been on a carousel, or you're on a ride at an amusement park, and you're on something that is going round and round and round.

因为，听着，如果你曾经坐过旋转木马，或者你在游乐园里坐过过山车，你坐的东西在不停地旋转。

Two things, alright? One, you know you're moving, there's no doubt.

你会知道两件事，对吗？第一件，你知道你在移动，这个无可置疑。

And the other thing is, you know that unless you hold on tight, you're gonna go flying out because of centrifugal force, right?

第二件，你知道除非你抓得紧，不然你就会因为离心力而飞出去，对吗？

Female student: So, if I understand you, for the average person 400 years ago, there was no evidence that we're moving at high speed, right?

女学生：所以，如果我理解得对的话，对于400年前的普通人来说，没有证据表明我们正在高速运动，对吗？

Since everything was securely on the ground, and no one was flying off into space?

因为所有东西都好好地待在地面上，没有东西飞到空中？

Male professor: Yes. And in particular.

男教授：是的。就是这样。

And this was one specific difficulty for people in the period, even if they thought that there was some sort of force that maybe kept you and me and buildings and things on the surface of the Earth.

对当时的人而言，这是一个特定的困难，即使他们认为有某种力量可能把你、我、建筑物和其它东西都保持在地面上。

Their theory about the nature of the atmosphere was that nothing was holding it down.

他们关于大气性质的理论是，没有任何东西能阻止它。

So, if, if you can understand that way of thinking, then clearly, if the Earth, was moving at a great speed, we should have lost all our atmosphere a long time ago.

所以如果，如果你能理解这种思维方式，那么很明显，如果地球以很高的速度运动，我们早就失去了所有的大气层。

You know, it would be, like, trailing away behind us.

这就像是，大气层在我们身后逐渐消失。

And so I want to try a little thought experiment. Because, I, I think that what we'll find is that some of us have ideas about motion that actually fit with antiheliocentrism.

所以我想试着做一个小小的思维实验，因为，我，我觉得这个实验会显示出，我们中的一些人所持有的有关运动的观点还是符合反日心说的。

Male student: Antiheliocentrism! No way. This is the twenty-first century.

男学生：反日心说！不可能的。现在可是21世纪。

Male professor: Well, then, let's see. So, picture the following: you're at the equator moving at sixteen-hundred kilometers per hour, OK?

男教授：嗯，那我们就拭目以待吧。想象一下下面这个场景：你站在赤道上，以1600千米/小时的速度移动，好吧？

And you drop something, small and light, like a matchstick, for example. Where's it gonna land?

然后你扔出了又小又轻的什么东西，比如说一根火柴。那么火柴会掉在哪里呢？

Male student: That's easy. It'll be long gone. The matchstick is so light, it'll fly right out of my hand and end up way behind me somewhere.

男学生：很简单。会飞出很远。火柴太轻了，会从我的手里飞走然后落在我很后面的某个地方。

Male professor: Ahh…actually, that matchstick you dropped? It'll land right at your feet.

男教授：实际上，你丢下的那根火柴？它会刚好落在你的脚下。

Male student: What?!

男学生：什么？！

Male professor: Well, let's think about it. You forgot to consider that the Earth's rotating at sixteen-hundred kilometers per hour at the equator…

男教授：我们来看看这件事。你忘了考虑地球在赤道以每小时1600公里的速度自转……

And you, me, the air, and that matchstick, we're all moving together at the same speed, even though it doesn't seem or look or feel like we're moving.

你，我，还有空气，还有那根火柴，也会以相同的速度移动，即使确实看不出来也感觉不出来我们在移动。

So class, clearly, even today, we actually have some inclination to think that if the Earth were moving around at a great speed, we ought to see signs of it.

所以同学们，很显然，即使是今天，事实上，我们倾向于认为，如果地球以很高的速度运动，我们就应该看到它的痕迹。

Perhaps now you're less inclined to dismiss those who once found heliocentrism so hard to believe.

也许你们现在能够稍微理解一点那些曾经觉得日心说难以理解的人了。

OK, let's move on…

好吧，我们继续……