Alpha, the fine structure constant.

In modern quantum physics, the non-dimensional constant,
alpha, shows up so often it is considered to be a fundamental physical constant in its own right.  Its official definition, however, is a rather cryptic composite of other constants:

The definition of alpha can be simplified, however, by considering the classical electron radius; the hypothetical distance between two quantum charges which would result in a potential energy of mec2.


Where lambda-C is the Compton wavelength of the electron.

This, more civilized, definition will be used in this web site.