The different types of radiation, or the electromagnetic spectrum, is energy that can travel through a vacuum or matter in waves. This type of wave does not need a medium. The specific types are radio, which are the longest, and then in between visible, infrared, ultraviolet, x-rays,microwaves, and gamma-rays being the shortest. But for now, that's all just names. Each wave in the spectrum names a different portion of wavelength, with the waves traveling from places like the earth to the universe! But the lengths are also very important, I mentioned earlier that the radio waves are the longest starting around 8x10^6m to 3x10^0m, and then going down in the order microwaves, infrared, visible, ultraviolet, x-rays, and then gamma-rays with the starting length of about 1x10^-10m.
radio tower |
black hole |
The other wave that I think is also cool is infrared. Infrared waves are just past the visible spectrum and we use it for so many cool things like changing the channel on the TV, but also for thermal imaging and astronomy. We use infared in termal imaging because usually, infared waves show heat, when used by a special sensor. Things, such as ourselves, lamps, and fire are found with these sensors. That is one way we can see the stars otherwise hidden behind the dust in that nebula. The infrared wave is very useful to other things besides looking at far away nebulas. It is very useful for short distance signals, such as a remote and TV as metioned earlier, and even walkie-talkie head sets.
The Electromagnetic Spectrum is a variety of waves and clasifications, letting us learn about the secrets of the universe and other things.
http://missionscience.nasa.gov/ems/01_intro.html
http://school.discoveryeducation.com/lessonplans/interact/electromagneticspectrum.html
http://www.darvill.clara.net/emag/index.htm