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Infared Waves
==     When infared waves hit our body we feel heat. Infared waves are a type of electromagnetic waves, meaning they pass can pass through empty space. With wavelengths between about one thousandth and 0.7 millionths of a meter, they can be very strong and dangerous like the ones eminating from the sun or they can also be weak and  let off so little energy that you can't feel them. Electromagnetic waves are emitted by every object and special infared detectors have bee created to see them. There different uses for infared technology, such as scanners that are used to create maps with by scanning a forest. When a infared image appears on srceen the more heat an object has the brighter it is. Forests and vegitation are cooler than there surroundings so they are recognizable on a infared screen. Night vision googles used by the military, in the dark, also use infared technology. Infared radiation was first noticed by William Herschel a astronomer in the 1800's. This kind of technology has become an important tool and utility in many situations. ==

X-Rays
X-rays are electromagnetic waves with very high frequencies. Their wavelengths are short than UV rays but longer then Gamma rays. With frequencies between 30 petahertz a 30 exahertz an X-ray has enough energy to go through bone and muscle. However dense metals such as lead is strong enough to stop X-rays. X-rays are put to use by doctors who use them to see if the bones or cartilage in someones body is damaged. X-rays are able to see bones because when a X-ray goes through your body the more dense material such as bone leaves behind a shadow. Doctors have learned to use this method to diagnose medical and dental conditions. The discovery of X-rays is credited to Wilhem Rontgen. He discovered it when he was working with a cathode light tube, which he noticed when he charged it with electricity was able to go through a black sheet of paper. X-rays and Gamma rays are the two strongest waves. Their main differences are wavelength, frequency, and that X-rays originate from electron and Gamma rays come from atomic nuclei.