The quantum of action, named after Max Planck, also known as the Planck constant, is a natural constant that frequently occurs in [[Quantum Mechanics|quantum physics]]. It is used, for example, to calculate the energy of [[Photon|photons]]. The quantum of action also appears in the [[Schrödinger Equation]].
In comparison to everyday quantities, Planck's constant is a tiny number. Its value is
$
h = 6.627 \cdot 10^{-34}\, \text{Js}
$
We used scientific notation for the number here to spare ourselves some writing. $10^{-34}$ stands for $0.0\dots\text{another 32 0s}\,1$. That is a really small number.
The small size of the Planck constant is one of the reasons why we rarely see quantum effects in everyday life.
>[!read]- Further Reading
>- [[Black Body Radiation]]
>- [[Schrödinger Equation]]
>[!ref]- References