I agree with Lawrence Crowell it would be wise to stick with dimensionless units. They're not many non integer constants in physics without a obvious purely mathematical definition such as PI and e have but the Fine Structure Constant is one of that rare breed of pure dimensionless numbers that mathematicians have never found anything special about but physicists have.

If you place 2 electrons a distance d apart they will repel each other because they will both have a negative charge; call the energy needed to overcome that repulsion Er and let's call the energy in one photon of light with a wavelength of (2PI)*d Er. Er/Ep is the Fine Structure Constant (FSC), the ratio of 2 energies is obviously a pure number and is very close to 1/137 but not exactly so, the reciprocal of the FSC obtained experimentally is 137.035999139 plus or minus 31 in the last two digits. It can also be calculated theoretically using Feynman Diagrams and the result is 137.035999173 plus or minus 35 in the last two digits. Another physical interpretation is the ratio of the velocity of a electron in the innermost orbit of the Bohr model of the Hydrogen atom to the velocity of light in a vacuum. Is the Fine Structure Constant a rational number? Is it a algebraic number? Is it a transcendental number? Nobody knows. John K Clark -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.