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Electromagnetic Radiation. What is electromagnetic radiation ?. Transverse waves that transfer energy by radiation Examples: Gamma Rays, Visible Light, Infrared, Ultraviolet, Radio Waves, X-rays and Microwaves. How to Interpret the ElectroMagnetic Spectrum.
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What is electromagnetic radiation ? • Transverse waves that transfer energy by radiation • Examples: Gamma Rays, Visible Light, Infrared, Ultraviolet, Radio Waves, X-rays and Microwaves
How to Interpret the ElectroMagnetic Spectrum • As the wavelength increases the frequency decreases • Increased frequency means more energy
Radio Waves • Electromagnetic radiation which has the lowest frequency, the longest wavelength, and is produced by charged particles moving back and forth; the atmosphere of the Earth is transparent to radio waves with wavelengths from a few millimeters to about twenty meters.
Microwaves • Electromagnetic radiation which has a longer wavelength (between 1 mm and 30 cm) than visible light. Microwaves can be used to study the Universe, communicate with satellites in Earth orbit, and cook popcorn.
Infrared • We often think of this as being the same thing as 'heat', because it makes our skin feel warm. In space, IR light maps the dust between stars. http://gallery.spitzer.caltech.edu/Imagegallery/image.php?image_name=ssc2003-06v3
Visible Light • Electromagnetic radiation at wavelengths which the human eye can see. We perceive this radiation as colors ranging from red (longer wavelengths; ~ 700 nanometers) to violet (shorter wavelengths; ~400 nanometers.)
Ultraviolet or UV • Electromagnetic radiation at wavelengths shorter than the violet end of visible light; the atmosphere of the Earth effectively blocks the transmission of most ultraviolet light.
X-Ray • Electromagnetic radiation of very short wavelength and very high-energy; X-rays have shorter wavelengths than ultraviolet light but longer wavelengths than gamma rays. http://chandra.harvard.edu/photo/2005/gctr_bin/bh_swarm_sm.mov
Gamma Rays • The highest energy, shortest wavelengthelectromagnetic radiations. Usually, they are thought of as any photons having energies greater than about 100 keV. (It's "gamma-ray" when used as an adjective.)