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

You are thinking of a physical wriggly worm of continuous particles radiating from the magnetron.

When in reality it’s more like waves on a shallow pond.

The screen more or less isn’t really blocking that radiation. Its kind of just chopping it up into a bunch of pieces so it’s more like a random fuzz

The waves are organized inside the microwave and “fuzzy” and ineffective outside the microwave.