Biography UV
image of the solar corona as seen in deep ultraviolet light at 17.1 nm by
the Extreme ultraviolet Imaging Telescope instrument aboard the SOHO
spacecraft]] astronauts.]]
Ultraviolet (UV) light is electromagnetic radiation with a wavelength
shorter than that of visible light, but longer than soft X-rays. It is so
named because the spectrum consists of electromagnetic waves with
frequencies higher than those that humans identify as the color violet
(purple).
UV light is typically found as part of the radiation received by the Earth
from the Sun. Most humans are aware of the effects of UV through the
painful condition of sunburn. The UV spectrum has many other effects,
including both beneficial and damaging changes to human health.
Discovery The discovery of UV radiation was intimately associated with
the observation that silver salts darken when exposed to sunlight. In 1801
the German physicist Johann Wilhel
