Definition:Planck's Constant

Definition
Planck's constant is the physical constant $h$ whose value is defined as:


 * $h = 6 \cdotp 62607 \, 015 \times 10^{-34} \, \mathrm {J \, s}$

where the units $\mathrm {J \, s}$ are joule seconds.

Planck's constant defines the quantum nature of energy and relates the energy of a photon to its frequency. It is used for describing the behaviour of particles and waves at an atomic scale. Planck's constant also occurs in Heisenberg's uncertainty principle.

Physical quantities with the same dimension include angular momentum and action.

Also see

 * Definition:Planck's Reduced Constant