Date: Wed, 10 Dec 1997 20:10:41 -0800
Reply-to: phys-l@mailer.uwf.edu
From: fredb@teleport.com
To: phys-l@atlantis.uwf.edu
Subject: lite questions
I have a couple of questions related to a light unit we are
doing.
1) If glass blocks ultraviolet light, why do glasses
need to be uv
protected.
2) If black lights are give off ultraviolet light,
why aren't they
harmful to our eyes? Or if they are harmful, why are they
used so much?
I guess I should answer that glass blocks some ultraviolet
light--knocks down the intensity some. The amount of
attenuation depends on the wavelength of the ultraviolet
light. Also, black light is harmful to unprotected eyes.
Tanning lamps with a lot of ultraviolet used in
environments with very little visible light can burn the
eyes and make them very painful. Don't ask me how I know!
wbn
Barlow Newbolt
Department of Physics and Engineering
Washington and Lee University
Lexington, VA 24450
Telephone and Phone Mail: 540-463-8881
Fax: 540-463-8884
e-mail: NewboltW@madison.acad.wlu.edu
"Prediction is very difficult, especially about the future."