From: utzoo!dciem!mmt Newsgroups: net.physics Title: Re: Query about "averaging" photons ... - (nf) Article-I.D.: dciem.167 Posted: Wed Feb 2 16:42:57 1983 Received: Wed Feb 2 16:50:36 1983 References: uiucdcs.1419 As you shorten the wavelength beyond the normally visible, near ultraviolet becomes less deep indigo, returning toward blue in hue, but also less saturated (greyer) than light of the same hue but longer wavelength. You can't see it very much further in the short wavelengths when you stimulate the retina than by just looking (don't try: it damages the (?) cornea). Martin Taylor