Bose-Einstein Condensation

Abstract

The basis underlying the great advance of the Planck distribution law for black body radiation in 1901 was a mystery in the era before the development of quantum mechanics in the late 1920s. Early attempts to calculate this spectrum using classical statistical mechanics had failed dismally, resulting in the catastrophe of the Rayleigh-Jeans law. In 1924 S. Bose found the correct way to evaluate the distribution of identical entities such as Planck’s radiation quanta that allowed him to calculate the Planck spectrum using the methods of statistical mechanics. Within a year Einstein had seized upon this idea, and generalized it to identical particles with discrete energies. The result was the Bose-Einstein (BE) statistical mechanics of identical particles, even before the idea of wavefunctions had appeared. The Fermi-Dirac statistics, and their contrast with BE statistics, came after the advent of quantum mechanics and the Pauli exclusion principle (antisymmetrization postulate).