fine-structure constant | has symbol α | ![2001-09-27 09:33:08.0 2001-09-27 09:33:08.0](facet.gif) |
has symbol α | ![2001-09-27 09:33:08.0 2001-09-27 09:33:08.0](facet.gif) |
has value 7.297352533 × 10-3 | ![has URL: http://physics.nist.gov/cgi-bin/cuu/Value?eqalph, 2001-09-27 09:33:08.0 has URL: http://physics.nist.gov/cgi-bin/cuu/Value?eqalph, 2001-09-27 09:33:08.0](facet.gif) |
has equation ![](http://physics.nist.gov/cuu/Constants/Value/gif/eqalph.gif) | ![2001-09-27 09:33:08.0 2001-09-27 09:33:08.0](facet.gif) |
has uncertainty 0.000000027 × 10-3 | ![2001-09-27 09:33:08.0 2001-09-27 09:33:08.0](facet.gif) |
has definition A "coupling constant," e2 / h bar c, approximately 1/137, that measures the strength of an interaction between a charged particle and the electromagnetic field. It gives a rough measure of the relative importance of relativistic and spin effects in the spectra of atoms. | ![has source: Hopkins, J. 1976 Glossary of Astronomy and Astrophysics, University of Chicago Press, 2001-09-27 09:33:08.0 has source: Hopkins, J. 1976 Glossary of Astronomy and Astrophysics, University of Chicago Press, 2001-09-27 09:33:08.0](facet.gif) |
has definition A parameter that measures the strength of the electromagnetic force. The fine-structure constant is a combination of other fundamental constants of nature - the electrical charge of the electron, the speed of light, and Planck's constant of quantum mechanics. | ![has source: Lightman, A., Brawer, R. 1990 The Lives and Worlds of Modern Cosmologists, Harvard University Press, 2001-09-27 09:33:08.0 has source: Lightman, A., Brawer, R. 1990 The Lives and Worlds of Modern Cosmologists, Harvard University Press, 2001-09-27 09:33:08.0](facet.gif) |
has definition A coupling constant e2 / h bar c, approximately equal to 1/137 (where e is the electron charge, h bar is Plancks constant, and c is the speed of light), that measures the strength of the interaction between a charged particle and the electromagnetic field. | ![has source: Silk, J. 1990 The Big Bang, W. H. Publishers, New York, 2001-09-27 09:33:08.0 has source: Silk, J. 1990 The Big Bang, W. H. Publishers, New York, 2001-09-27 09:33:08.0](facet.gif) |
is an instance of atomic constant | ![2001-09-27 09:33:08.0 2001-09-27 09:33:08.0](facet.gif) |
fundamental physical constant | has accuracy | ![2001-09-27 09:32:59.0 2001-09-27 09:32:59.0](facet.gif) |
has unit | ![2001-09-27 09:32:59.0 2001-09-27 09:32:59.0](facet.gif) |