Archive for History of Exact Sciences, Vol. 57, P. 395–431, 2003.
Although, since its discovery, the fine-structure constant has lost part of its magic, it is still a fundamental and unexplained number that physicists very much want to understand. Whatever its current status, it has an interesting history that goes back to the earliest days of quantum theory and illuminates important episodes in the history of modern physics. This essay examines the historical development of the fine-structure constant until about 1960 and the role it played in shaping parts of theoretical physics.Contents:
Introduction: The fine-structure constant.
Between Planck and Sommerfeld.
The fine-structure formula.
From quantum mechanics to Eddington.
Toward quantum electrodynamics.
A number derived a priori.
Responses to Eddington’s theory.
Alpharology.
Max Born and the number 137.
Does alpha vary in time?
Conclusion.
