Planck's constant cultural definition

A universal constant, first discovered by Max Planck, that states the mathematical relationship between the frequency of an electromagnetic wave and the energy in that wave. Planck's discovery unifies the seemingly contradictory observations that energy sometimes acts like a wave and at other times acts as if it is made up of particles.

• Knowing Planck's constant sets the scale of energy for events in which the atom and subatomic particles take part.