8.S.III.2

The electromagnetic spectrum From long waves, to radio waves, to light waves, to x-rays, to gamma rays Called “electromagnetic” because the radiation is created by an oscillating electric field which creates an oscillating magnetic field at right angles to it, which in turn creates an oscillating electric field at right angles, and so on, with both fields perpendicular to each other and the direction the wave is moving. The light spectrum: from infrared (longest) to red, orange, yellow, green, blue, violet (shortest) Speed in a vacuum of all electromagnetic waves including light: 300,000 km per second, or 186,000 miles per second; a universal constant, called c