Ultraviolet Rays

What are ultraviolet rays?

• A type of electromagnetic wave with a shorter wave length. They are invisible to the naked eye, and typically come from the suns radiation to the earth.

• Ultraviolet means beyond violet, and violet is the color of the shortest wavelength of visible light.

The DiscovererThe Discoverer

Johann Wilhelm Johann Wilhelm RitterRitter

Dec 16 1776- Jan 23 1810Dec 16 1776- Jan 23 1810 German chemist and German chemist and

physicistphysicist Died at a young age, they Died at a young age, they

believe it was because he believe it was because he used his own body in his used his own body in his electrical experiments.electrical experiments.

How did he discover it?How did he discover it?

After hearing of Hershel's discovery After hearing of Hershel's discovery of Infrared light, and it being non of Infrared light, and it being non visible, he decided to conduct visible, he decided to conduct experiments as well.experiments as well.

Ritter realized that silver salts/silver Ritter realized that silver salts/silver chloride darkened when it was chloride darkened when it was exposed to sunlightexposed to sunlight

He called them de-oxidizing rays He called them de-oxidizing rays (taking the effects of oxygen away)(taking the effects of oxygen away)

Frequency and WavelengthFrequency and Wavelength

750-30,000 THz = 750-30,000 THz = frequency rangefrequency range

400-10 nm = 400-10 nm = wavelengthwavelength

How is it used?• In medicine it kills bacteria and

viruses• Disinfecting water, food

processing• Sun tanning• security (credit cards, passports,

drivers license)• Black lights• Fire Detectors• Sterilization• Lasers• Determining substance abuse in

public placesA bird shows up on many Visa cards when placed under UV lights

Does it have any effects?Does it have any effects? Therapeutic purposes Therapeutic purposes

(such as treating skin (such as treating skin disease)disease)

It is the biggest cause It is the biggest cause for skin cancer.for skin cancer.

Ages skin fasterAges skin faster Trigger allergic Trigger allergic

reactionsreactions Long exposures can Long exposures can

result in blindness over result in blindness over timetime

SunburnsSunburns

Malignant melanoma-one of the three skin cancers you can get.

Interesting…• Ultraviolet tattoo• Suntans come from

after they have killed your skin cells, and damaged others.

• On average around 70 - 80% of a person’s life time exposure to the sun occurs by the age of 18.

• Approximately 80 - 85% of UV rays pass through clouds.

• Cat urine, and scorpions both glow in black light

Does this work?

You can buy it on ebay…

sourcessources

http://en.wikipedia.org/wiki/Ultraviolet_Rayhttp://en.wikipedia.org/wiki/Ultraviolet_Rayss

www.spacebuffs.com/glossarywww.spacebuffs.com/glossaryGoogle images: UV raysGoogle images: UV rays information from the BG health department information from the BG health department

www.hvbg.de/e/bia/fac/strahl/uv_str_e.pdfwww.hvbg.de/e/bia/fac/strahl/uv_str_e.pdfhttp://simun.inspiringteachers.com/customhttp://simun.inspiringteachers.com/custom

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