where , and are all constants. Since and have been defined from tallies of quarks, the orbital radius is thus established from quark counts too. But now we use it to make a rudimentary account of the expanse or extent of P.
Any non-rotating particle has no orbital radius because when . So particles that are shaped like points or lines are mathematically described by saying .
For photons, the angular momentum is always one. And the wavelength is related to the energy by . So the orbital radius of a photon can be written as
Then a circular perimeter of is the same as one wavelength.