Electromagnetic Wave Facts



  • The electromagnetic spectrum is the complete range of radiation sent out by electrons. It is given off in tiny packages of energy called photons, which can be either particles or waves.
  • Electromagnetic waves vary in length and frequency. The shorter the wave, the higher its frequency (and also its energy).
  • The longest waves are over 100 kilometers long; the shortest are less than a billionth of a millimeter long.
  • All electromagnetic waves travel at 300,000 kilometers per second, which is the speed of light.
  • Visible light is just a small part of the spectrum.
  • Radio waves, including microwaves and television waves, and infrared light, are made from waves that are too long for human eyes to see.
  • Long waves are lower in energy than short waves. Long waves from space penetrate the Earth’s atmosphere easily (but not solids, like short waves).
  • Ultraviolet light, x-rays and gamma rays are made from waves that are too short for human eyes to sec.
  • Short waves are very energetic.
  • The range of waves from space are blocked out by Earth’s atmosphere – which is fortunate because penetrate some solids, and UV rays can they are dangerous. X-rays and gamma rays spectrum. The waves are shown emerging from the Sun, as the Sun actually emits almost the full range of radiation in the electromagnetic radiation. Fortunately, the atmosphere damage living tissue, causing skin cancers. protects us from the dangerous ones
  • The shortest ultraviolet rays in sunshine are dangerous, but longer ones give you a sunlit small doses. In large doses even long UV my, cause cancer. Visible light varies in wavelength from violets (shortest) through all the colors of light to red (longest). Infrared light is the radiation given out by objects. This is why infrared-sensitive imaging cameras can see hot objects like people in the dark.