Search results
Results From The WOW.Com Content Network
Average UV at noon 1996-2002 (European Space Agency) The ultraviolet index, or UV index, is an international standard measurement of the strength of the sunburn-producing ultraviolet (UV) radiation at a particular place and time. It is primarily used in daily and hourly forecasts aimed at the general public.
The latest TikTok tanning trend involves monitoring the UV index and timing sunbathing sessions to when it's high, but experts say that exposing yourself to strong ultraviolet rays is a bad idea.
Extreme UV and X-rays are produced (left of wavelength range) but comprise very small amounts of the Sun's total output power (area under the curve). Although the solar corona is a source of extreme ultraviolet and X-ray radiation, these rays make up only a very small amount of the power output of the Sun (see spectrum at right).
UV damaged polypropylene rope (left) and new rope (right) UV degradation is one form of polymer degradation that affects plastics exposed to sunlight. The problem appears as discoloration or fading, cracking, loss of strength or disintegration. The effects of attack increase with exposure time and sunlight intensity.
UV observations can also provide essential information about the evolution of galaxies. They can be used to discern the presence of a hot white dwarf or main sequence companion in orbit around a cooler star. [3] [4] The ultraviolet universe looks quite different from the familiar stars and galaxies seen in visible light.
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
In reflected UV photography the subject is illuminated directly by UV emitting lamps (radiation sources) or by strong sunlight. A UV transmitting filter is placed on the lens, which allows ultraviolet radiation to pass and which absorbs or blocks all light and infrared radiation. UV filters are made from special colored glass and may be coated ...
Two photographs showing the effect of applying sunscreens in visible light and in UVA. The photograph on the right was taken using ultraviolet photography shortly after application of sunscreen to half of the face. The sun protection factor (SPF rating, introduced in 1974) is a measure of the fraction of sunburn-producing UV rays that reach the ...