Planck-Einstein Relation

Discovered by: Max Planck, received the Nobel Prize in Physics in 1918.

What is it? The formula states that the energy of a photon, E, is proportional to its frequency, v.

Why is it important? Integral to quantum mechanics, it accounts for the quantised nature of light, and plays a key role in understanding phenomena such as the photoelectric effect, and Planck's law of black body radiation.