by: Tami O’Connor
The sun is our primary source of ultraviolet radiation, however, there are a number of artificial sources of UV light including black lights, tanning beds and mercury vapor lamps. Ultraviolet radiation is usually considered to be a bad thing for very good reasons.
Generally speaking, there are three types of UV radiation here on Earth: UVA, UVB and UVC. Though the most destructive, UVC is almost never seen in nature because the earth’s atmosphere absorbs all of it. Though less destructive, overexposure to UVB can lead to all kinds of maladies including sunburn, some forms of skin cancer and cataracts. Read the rest of this entry »
Posted by Tami O'Connor 
by: Norm Barstow
Photographing Science