bach2roq science courses

light 1 - speed, frequency and wavelength

Light is very fast. It is one of the fastest things that we know in the universe, and arguably the fastest by some under certain circumstances.

Light is currently thought of as a wave and a particle, in a form known as a photon.

The speed of light in a vacuum is 3 X 10^8 m/sec and is given the symbol c.

The frequencies (f) of visible light range from 4 X 10^14 Hz to 7.5 X 10^14 Hz (or 400 to 750 GHz)

Hence the wavelength of light is for red light of frequencey 4.74 X 10^14 Hz is

3 X 10^8 / 4.74 X 10^14 = 6.33 X 10^-7 m = 633 nm