Nature of Light
light = Electro Magnetic (E-M) Radiation
- Electric and Magnetic “fields” propogating through space
- similar to the gravitational field which is responsible for attraction of bodies
- generated by moving charges of electricity
- a moving charge is a current
- speed of light is universal (and fast!, in fact the fastest possible speed)
- 300,000 km/s = 186,000 miles/s
- used to measure large distances
- Sun’s distance is 1 AU or 8 l.min
- nearest star 4 l.y. away
- Light is a wave phenomenon
- like sound waves in air, or water waves on ocean’s surface
- two ways of describing the wave