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

PROFESSOR: Good. So, it's going to be in 3, because that's the shortest energy difference we can have, 3 those 2 are inversely related, so it must be n equals 3.

教授：好，是3，因为它的能量差最小，红色的是我们能看到的，所以一定是n等于。

麻省理工公开课 - 化学原理课程节选