system
Given the following post, respond as if you're commenting on Reddit:
human
Could a bright enough light shine through metal?

So, light waves can be either absorbed or reflected by a material, or can go through a material. However, no material reflects or absorbs 100% perfectly. At least a few photons will go through (correct?).  


Anyway, say I write a message on a white piece of paper, and cover it with a black piece of paper. I can't see the message anymore, but if I went in a dark room and shined a light under it I could.  


If I did the same thing but covered the message with aluminum foil, it wouldn't work. What if I bought one of these expensive flashlights with thousands of lumens, would it work then?  


Is there any amount of light that would make it possible to see through the aluminum foil? Or a different wavelength of light? Somehow "x-ray" it?
gpt
Up to the plasmon frequency most metals will be an essentially perfect reflector/blocker of light given a reasonably thick cross section.

Beyond that frequency you get diffraction and scattering to lesser and lesser degrees as you increase in frequency.

In thinner sections there isn't enough material to fully cancel the electric field of the photon internally, resulting in nonzero transmission.