That's why it's natural to point to the moment of star when we say that's when my death occurs.

所以很自然的，我就死在星号这里。

耶鲁公开课 - 死亡课程节选

But for now let's simply say that we have a diffraction which we know occurs only by wave-like behavior and it involves the use of x-rays. Why x-rays?

但现在让我们来简单假设一下,我们知道,只波才发生衍射,而且衍射涉及了X光的使用，为什么是X光？

麻省理工公开课 - 固态化学导论课程节选