Fine structure constant

The fine structure constant, a numerical dimensionless constant represented by the symbol α (alpha), of which the value is close to 1/137, is related to the electromagnetic interaction. Alpha governs the electromagnetic force, which is responsible for the cohesion of atoms and molecules, by "holding" the electrons together.

Its exact value was: 0.007297351 +/- 0.000000006, until a new measurement by Gerald Gabrielse improved the accuracy by a factor of 10: α -1 = 137.035 999 710 (96)