CAS AS 102 Lecture Notes - Electric Field, Roygbiv, Electromagnetic Spectrum
Document Summary
Light is a messenger, it can tell us the temperature of objects, what they"re made od, and the speed they"re moving. Two people with lanterns stand on hills distant from one another. One person removes the shutter from their lantern, when the other sees the light they remove the shutter from their lantern. Galileo concluded that the speed of light must be very high. There fore, very large distances or very accurate clocks are needed. In 1850 fizeau and foucault experimented with light by bouncing it off a rotating mirror and meauring time for it to return. The light returned to its source at a slightly different position because the mirror has moved during the time light was traveling. In 1873, james maxwell wrote four famous equations describing electricity and magnetism, and predicted that em waves tavel at the speed c. C is exactly the same as the speed of light.