ml wrote in :

i was sorta wondering what a 'wave' looks like in 3d

what got me thinking was i know my microwave oven's door has a screen
such that the holes are supposed to me smaller than the microwave itself
so it dosn't leave the area

The explanation for why that screen works is that each hole is a very short
wavequide. If you calculate the attenuation in such a wavequide the
frequency involved, you have your answer as to why it works as it does.

Owen