Brian D Williams writes:
> This of course is why you have a perforated metal screen in the
> front of your microwave oven, the wavelength is larger than the
> openings in the mesh, so they can't escape and you can safely watch
> so you don't burn your mac'n'cheese.....
Microwaves are not so easy. Things can be blocked by a mesh, yet radiate like crazy through a loose rivet.