GRAVITATION, THERMODYNAMICS, AND THE FINE-STRUCTURE CONSTANT

The dimensionless fine-structure constant alpha e(2)/(h) over barc similar or equal to 1/137.036 has fascinated many scientists since its introduction by Sommerfeld almost a century ago. Dirac and Feynman have conjectured that this important physical constant may be composed of fundamental mathematical quantities like pi. In this essay we argue that, the interplay between gravity, quantum theory, and thermodynamics may shed much light on the origins of this mysterious constant. In particular, we show that a unified quantum theory of gravity may set a lower bound on the value of the fine-structure constant, alpha > ln 3/48 pi similar or equal to 1/137.3.