The Electromagnetic Spectrum: Inra-red Radiation, Visible Light, Ultraviolet Radiation
The middle of the Electromagnetic spectrum is comprised of Infra-red radiation, Visible Light, and Ultraviolet radiation. These types of waves have a wide range of usage from imaging in telescopes, to creating colors for our eyes, and to making our glowsticks glow.
Infra-red radiation has a wavelength range of 1 to 1000 micrometers and has a shorter wavelength and higher frequency than Microwaves, but a longer wavelength and lower frequency than Visible Light waves. Infra-red radiation was first discovered in 1800 by William Herschel through placing a thermometer beyond the red end of the visible light spectrum created by a prism. These waves are used in the Kepler Telescope, which is in outer space, by NASA to take picture of distant stars and galaxies.
Visible Light has a wavelength of 380 to 700 nanometers; it has a shorter wavelength and higher frequency than Infra-red radiation waves, but a longer wavelength and lower frequency than Ultraviolet Radiation waves. Visible Light waves can be seen by the naked human eye when light passes through a prism. When this happens we can see the colors of our world. This type of wave is important in our day to day lives, because it tells us which color traffic lights, rainbows, and stop signs are. Without Visible Light waves our lives would be colorless and dull.
Ultraviolet Radiation waves have a wavelength of 100 to 400 nanometers; they have a shorter wavelength and higher frequency than Visible Light waves, but a longer wavelength and lower frequency than X-ray waves. These types of waves were first found by Johann Ritter in 1801 through positioning a photographic plate past the violet part of the visible light spectrum created by a prism. Today our Sun emits the full range of Ultraviolet waves that can be deadly to humans if taken directly; however thankfully the ozone layer of the atmosphere reflects most if not all Ultraviolet waves.
Last on the Electromagnetic spectrum are X-ray waves, and Gamma ray waves. These can be harmful to the human body, be used in medical scanning, and tied to the creation of the Hulk.
Picture Source: archives.library.illinois.edu
