We have 266, as some of you might know who saw me counting ping-pong balls the other day in office hours.

看到了这些发泡胶球事实上,可以当作单层金原子核,我们有266个乒乓球。

麻省理工公开课 - 化学原理课程节选

So, 13 backscattered. TAs, if you can maybe pick up these ping-pong balls for me.

把这些球捡起来，我觉得如果，我摔倒一定很搞笑。

麻省理工公开课 - 化学原理课程节选

And again, you don't teach an animal to play Ping-Pong by waiting for it to play Ping-Pong and then rewarding it.

同样，你并不能通过等待动物打乒乓球,然后给其奖励,来使动物学会打乒乓球。

耶鲁公开课 - 心理学导论课程节选

It's not going to be a backscatter event if your ping-pong ball hits the frame or these strings, or the top part.

打到原子核了就是背散射,如果打到框上。

麻省理工公开课 - 化学原理课程节选

So, it'll be considered a backscatter event if your ping-pong ball hits one of the nuclei.

什么情况是背散射,如果你们的乒乓球。

麻省理工公开课 - 化学原理课程节选

All right. So, we'll come around and get ping-pong balls to the rest of you.

还有什么问题吗？如果你们,还没有乒乓球的话请举手，还有问题吗？

麻省理工公开课 - 化学原理课程节选

Those of you who have your ping-pong balls can now begin the experiment.

好，我们会到这边来把球给你们,已经拿到球的同学就可以开始试验了。

麻省理工公开课 - 化学原理课程节选

But in our case, the probability of backscattering is going to be the number of balls that backscatter, and that's going to be divided by the total number of ping-pong balls.

用20除以132000，但现在背散射,的概率是被散射回来的小球，除以总的小球数,你们记得。

麻省理工公开课 - 化学原理课程节选

More recreational, Skinner was fond of teaching animals to play Ping-Pong.

更好玩的是，斯金纳喜欢教动物们打乒乓球。

耶鲁公开课 - 心理学导论课程节选

PROFESSOR: So, as you're getting your ping-pong balls -- do not throw them yet.

如果你觉得，你的准心很好的话，你们现在都拿到乒乓球。

麻省理工公开课 - 化学原理课程节选

Raise your hand if you don't if you don't have a ping-pong ball yet.

这样就可以算,背散射的概率了。

麻省理工公开课 - 化学原理课程节选

We have 266 ping-pong balls, and we need someone, hopefully you, to be some radioactive material that are going to be emitting these ping-pong balls. And when the time comes, in just a minute, I'll ask the TAs to come down and hand these out very quickly to you, so we can do this experiment.

你们有些人那天，看到我在办公室数乒乓球，我们需要几个人,希望是你,来作为放射材料，放射这些乒乓球,等会我会让助教,把这些球发给你们。

麻省理工公开课 - 化学原理课程节选