Eli5 Why does the wavelength instead of the amplitude prevent some radiation from penetrating a small hole or screen?

Question

For examples the screen on a microwave that lets light through, but not microwaves. I am having trouble visualizing it.

In: 31

Answer 1

The amplitude is not the physical size. It is the strength – a higher amplitude does not make it wider or taller or anything. It’s how strong it is.

Higher amplitude means more light, so if half makes it through then more light will make it through, but that’s all.