弗格森说：“鲁尼在赛季前的热身中表现很棒，目前他的体能很好，他从来坐不住，他有无穷无尽的能量，他是球队的一笔巨大财富，有趣的是要看看他与维尔贝克怎么搭档，目前他们做得不错，但是显然小豌豆回来了，我将面临选择的难题，因为他打入过很多进球，并且贝巴在赛季前也展示了比较不错的状态。”

"Rooney’s been flying in pre-season," said the boss. "His fitness is terrific, he has that restless energy, he never stands still.

youdao

相反，我们还要投入大量能量，这可要花上一大笔钱。

Instead we put a lot of energy in and it costs a lot of money.

youdao

我强调这点的原因是为了让你们理解在合理的时间内抵达那里所需要的巨大能量.你不仅必须飞得很快 还要快到接近物理定律所允许的极限.为了达到那种速度 你消耗的能量将超过当今整个人类文明一年所用的能量（减速时也一样）.所以底线是：钱 一大笔钱.

Almost as fast as the absolute laws of physics perm it. And you have to use more energy to reach that speed (and then slow back down) than all of human civilization is currently using in a year.

youdao

Also, what's the energy per photon of this red laser pointer, and then it's also worth trying a calculation dealing with intensity. So let's also try calculating the numbers of photons that would be emitted by this laser pointer, if, for example, we were to use it for 60 seconds and this were a one milliwatt laser.

同样，红色激光笔的,每个光子能量是多少，这也值得用处理强度的方法计算一下,让我们也计算一下,有多少光子会从这个激光笔射出，举个例子，如果我们使用它持续60秒,这里会有一毫瓦的激光。

麻省理工公开课 - 化学原理课程节选