ultra voilet light

[mr_pointment]

how does glass block it?

[jake-the-peg]

Ultra violet light is just part of the electromagnetic spectrum from radio waves up to x and gamma rays.

If you think about it a bit you'll probably see that different materials transmit or absorb different frequencies of radiation.

Photons of light have a specific frequency, and that equates to a certain discrete energy, if the material the photon hits can be excited to a new energy state by exactly that amount then it can absorb that photon.

Most metals will reflect or absorb most frequencies - they effectively have a sea of electrons that can be excited by almost any energy.

Non metals tend to have fewer possible energy states and absorb more specific energy ranges.

Few materials have energy bands that can block frequencies as small (and hence energies as high) as x or gamma rays

[morbidstorm]

Jake the peg - are you a science teacher by any chance?!!!

[jake-the-peg]

(Checks jacket elbows for patches) Nope

I was a physicist once but made the fundamental discovery that there's more money in computers!

[mr_pointment]

i'm agassed by your answer jake but i'll take your word for it.it's allways baffled me

[mr_pointment]

Light beyond the visible

[heathfield]

Jake - where's the money in computers? I took mine to bits, but didn't find any. (You'll note i've managed to re-assemble it and so far it still $*55#~%�...