Boltzmanns Atom: The Great Debate That Launched A Revolution In Physics

Born in Austria and something of a bumpkin by nature, the 19th-century physicist Ludwig Boltzmann did not fit in easily in the highly cultured German universities at which he taught for many years. To add to his difficulties, Boltzmann stirred up controversy by proposing that scientists could make intelligent guesses about the behavior of atoms, which, though they moved randomly, could be described by certain probabilistic generalizations. His suggestion, hinging on novel interpretations of statistical theory, was not immediately acclaimed. "To an audience of physicists raised in the belief that scientific laws ought to encapsulate absolute certainties and unerring rules," writes scientist and journalist David Lindley, "these were profound and disturbing changes."

Opposed by the then-influential physicist and philosopher Ernst Mach, who urged that scientists stick to classical thermodynamics, Boltzmann was hard-pressed to convince his colleagues that the behavior of atoms could be explained by laws thought to apply only to the gaming table. Mach objected, and with some cause, that "the fact that the theory worked was not enough to prove that the assumptions on which the theory rested were true." It would take the next generation of scientists, among them Albert Einstein, to provide more solid proof for Boltzmann's hunches. And, while Mach's contributions to physics have largely been superseded, Boltzmann's endure in quantum mechanics and the Maxwell-Boltzmann distribution for the velocities of atoms in a gas. In this lively account, David Lindley tells the story of Boltzmann's many failures, and of his eventual success. --Gregory McNamee