Introduction: Electromagnetic waves are waves which can travel through the vacuum of outer space. The electromagnetic spectrum is the range of all possible frequencies of electromagnetic radiation. The first discovery of electromagnetic radiation other than visible light was in the 1800’s, when William Herschel discovered infrared light. He was studying the temperature of different colors when he noticed that the highest temperature was beyond red. Although there are two types of waves, transverse and longitudinal, all the waves in the spectrum are transverse. The electromagnetic spectrum consists of radio waves, microwaves, x-rays, gamma rays ultraviolet rays, infrared rays and visible light.