UV Light: from sunshine to sunbeds

Consider your sunburn from those hot days in summer; from that time you fell asleep in the brilliant sun. Remember now? You blamed it on the sun screen not working. But what you didn’t know then was ultraviolet light is responsible for causing the painful, blistering-sensation on your skin known as a sun burn. Even though the Earth's atmosphere (stratosphere and ozone layer) shields the surface of the Earth from most of the ultraviolet rays that come from the sun, the rays can still peak through and leave an aching reminder. So be sure to use your sunscreen because those reminders could turn into something more dangerous: cancer. The light damages the skin and can become cancerous cells. The cells will have to be removed before they spread!

Ultraviolet light is created when an electron bounces from one level of energy to the next. The sun provides the main source of UV light for us, but there are other ways to have ultraviolet light. One way is in a sunbed. They are designed to leave the victim with a tan. The danger of a tanning bed is that it can also lead to health risks such as cancer. Another way you can see ultraviolet light is with a black light. It emits near ultraviolet light (you will learn about it later) to make objects under the light fluorescent (or glow in the dark).

The photo above was taken of the Earth in ultraviolet light. The basic definition for ultra violet light is light not visible to the human eye, which is why you can’t see yourself sun burning until you’re as red as a lobster! Interestingly enough, some animals can see the light, such as bumble bees. Animals use this light, or the resonace (when the natural and the forced frequencies match up at the same time) to communicate with eachother, such as a fish searching for his friend in an ocean. The ultraviolet light is only a portion of the electromagnetic spectrum, or “the range of all possible frequencies of electromagnetic radiation”. The frequency range for an ultraviolet light is 2.4 X 10^23 Hz to 1 kHz. The range of wavelengths is about 10nm to 400nm, or about the size of a single virus, like when you get sick. Although the wavelength is very small, scientists have determined there are three parts to the ultraviolet section of the spectrum: the near ultraviolet (NUV), the far ultraviolet (FUV), and the extreme ultraviolet (EUV). The difference between the three divisions can be distinguished by the wavelength of the ultraviolet light, and how energetic the radiation is. NUV is the closest portion of ultraviolet light to visible light. EUV is closest to X-rays type of light, and is the most energetic of all three types of ultraviolet light. FUV is in between EUV and NUV as far as energy, and has not been researched as well as the other two sections.

Picture One: Electromagnetic Spectrum

Picture Two: The Earth in UV Light

WORK CITED:

"The Electromagnetc Spectrum." National Aeronautics and Space Administration. N.p., n.d. Web. 17 

     Mar. 2010. . 

National Aeronautics and Space Administration. N.p., n.d. Web. 1 Apr. 2010. 

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Standford Solar Center. N.p., n.d. Web. 1 Apr. 2010. 
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