Arthur Erich Haas

Arthur Erich Haas (April 30, 1884, Brno - February 20, 1941, Chicago) was an Austrian physicist, noted for a 1910 paper he submitted in support of this habilitation as Privatdocent at the University of Vienna that outlined a treatment of the hydrogen atom involving quantization of electronic orbitals, thus anticipating the Bohr model (1913) by three years.

Haas’ paper, however, was initially rejected and even ridiculed. As noted in his autobiography, Haas recalls "When I lectured to the Chemical-Physical Society of Vienna... Lecher ...referred to the presentation during open discussion as a carnival joke" (The lecture was held during carnival time in Austria, February 1910). Soon thereafter, however, by September 1911 at a physical science convention in Karlsruhe, former detractors of Haas' work acknowledged it with greater enthusiasm as noted in a footnote: "We do not know what caused change of mind in 1911 and can merely suggest the general trend of thinking at the time: 1910 saw the beginning of a universal shift of opinion of the quantum concept."

The significance of Haas' work lay in the establishment of a relationship between Planck's constant and atomic dimensions, having been first to correctly estimate the magnitude of what is today known as the Bohr radius.