It has been called the “coupling constant” - or the measure of the strength of the electromagnetic force which governs how electrically-charged elementary particles (e.g., electron, muon) and light (photons) interact. It was introduced in 1916 by physicist Arnold Sommerfeld, in order to explain the observed splitting (or fine structure) of the energy levels of the hydrogen atom.
It is a crucial factor in many of the fundamental calculations in quantum physics.
There is no explanation for the constant's value, other than calculations which show that if it deviated by more than ± 4% or so, the structure of the universe would by so radically different that life could not have evolved, and so no-one would be around to observe and quantify it.
A further mystery is that it appears not to be constant. When discrepancies were originally identified, it was assumed that they could be explained by experimental error. The predominant current view is that it is changing by a measurable amount each year. (Technical details here )
Further info : Introduction to the constants for nonexperts US NIST Physical Measurement Laboratory
Also see :
Ideas for new topics, and suggested additions / corrections for old ones, are always welcome.
If you have skills or interests in a particular field, and have suggestions for Wikenigma, get in touch !
Or, if you'd like to become a regular contributor . . . request a login password. Registered users can edit the entire content of the site, and also create new pages.
( The 'Notes for contributors' section in the main menu has further information and guidelines etc.)
You are currently viewing an auto-translated version of Wikenigma
Please be aware that no automatic translation engines are 100% accurate, and so the auto-translated content will very probably feature errors and omissions.
Nevertheless, Wikenigma hopes that the translated content will help to attract a wider global audience.