ULTRAVIOLET

Ultraviolet or often we hear by UV. UV light is a kind of invisible. Bees, birds, butterflies, and other animals can see UV. 

UV is not visible because its wavelength is shorter than other lights that could be seen men, the 100-400 nm (nanometers). While other light, wavelength 400-800 nm. 1 nanometer = 0.000001 mm. 

UV divided into 3 groups. There are UVA, UVB, and UVC. 320 nm wavelength UVA-400 nm, 290 nm -320 nm UVB, and UVC 100 nm-290 nm. The more short wavelength, the more threatening! 

UV comes from the sun. There is also coming from other light sources. For example, mercury vapor lamps and UV lamps. Kedatanagn UV can be prevented to Earth.That's because of the ozone layer in Earth's atmosphere. Unfortunately, there is just a pass, that is UVA and UVB rays! 

This light has a positive and negative effects. Positive, UV can be used to kill bacteria and viruses. So it used to sterilize medical equipment and decontaminate the products and drug makanana obatan.Negatifnya, UV is dangerous because he will burn human skin, causing skin cancer, and make eyes sore. 

There are tips to avoid the evil of the UV. When doing activities outside the hot sun, you should wear protectors. Can sunglasses, lotions, shampoos and anti-UV, long sleeves, paying, and hat. 

So, we must be vigilant! Prevention is better than cure right?