http://physicsworld.com/cws/article/news/3525 I was reading this article about the neutron drop experiment. And it says " According to the researchers, these heights correspond to the peaks in a standing wave created when the de Broglie wave of the neutron interferes with its reflection from the mirror. The first peak agreed well with theory, but the researchers still need to confirm the presence of the higher peaks. " What does it mean when they say that the neutron interacts with its reflection from the mirror. Is this something to do with method of images or maybe reflected and transmitted wave.