Electromagnetic Waves
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Maxwell's Equations are as basic and fundamental and all-inclusive to ElectroMagnetism (E&M) as Newton's Laws of Motion are to Mechanics. Maxwell's Equations predict that a changing Electric field E creates a changing Magnetic field B. And a changing Magnetic field B creates a changing Electric field E.
Consider an electron moving up and down -- oscillating -- along a wire in an antenna. This electric charge has an electric field associated with it. As the electron oscillates, this causes an oscillation in the electric field E which causes an oscillation in the magnetic field B which causes an oscillation in the electric field E which causes an oscillation in the magnetic field B which causes an oscillation in the electric field E which causes an oscillation in the magnetic field B which causes an oscillation in the electric field E which causes an oscillation in the magnetic field B which causes an oscillation in the electric field E which causes an oscillation in the magnetic field B which causes . . . . . (well, I think you get the picture!).
This oscillation of the Electric and Magnetic fields continues on and on (and on and on and on). This is an Electromagnetic Wave (an E&M wave). Depending upon its wavelength, this may be a radio wave, a visible light wave, an X-ray, or a gamma ray.
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(c) Doug Davis, 2002; all rights reserved
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