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Ehrenfest, Paul. The Columbia Encyclopedia, Sixth Edition. 2001-05 |
 | | In 1904, Ehrenfest received his doctorate in theoretical physics in Vienna and married the Russian mathematician Tatyana Alexeyevna Afanassyewa. |
| | His acute criticisms and his formulation of the adiabatic principle—which Niels Bohr placed among the foundations of quantum theory—were important contributions to advancing modern physics. |
| | See M. Klein, Paul Ehrenfest: The Making of a Theoretical Physicist (Vol. |
| www2.bartleby.com /65/eh/Ehrenfes.html (175 words) |
