24 Facts About Paul Ehrenfest

Paul Ehrenfest befriended Albert Einstein on a visit to Prague in 1912 and became a professor in Leiden, where he frequently hosted Einstein.

Paul Ehrenfest died by murder-suicide in 1933, killing his disabled son, Wassik, and then himself.

Paul Ehrenfest was born on 18 January 1880 in Vienna to Jewish parents, who were originally from Lostice in Moravia.

Paul Ehrenfest excelled in grade school but did not do well at the Akademisches Gymnasium, his best subject being mathematics.

Paul Ehrenfest majored in chemistry at the Vienna Institute of Technology, but took courses at the University of Vienna, in particular from Ludwig Boltzmann on his kinetic theory of thermodynamics.

At the time, it was customary in the German-speaking world to study at more than one university, and in 1901, Paul Ehrenfest transferred to University of Gottingen, which until 1933 was an important site for mathematics and theoretical physics.

Paul Ehrenfest wrote his dissertation on Die Bewegung starrer Korper in Flussigkeiten und die Mechanik von Hertz and obtained his Ph.

Together with his wife, Paul Ehrenfest worked on it for several years; the article was not published until 1911.

In 1912, Paul Ehrenfest toured German-speaking universities in the hope of a position.

Paul Ehrenfest visited Berlin, where he saw Max Planck; Leipzig, where he met his old friend German mathematician Gustav Herglotz; Munich, where he met theoretical physicist Arnold Sommerfeld; Zurich; and Vienna.

Einstein recommended that Paul Ehrenfest succeed him in his position in Prague, but the plan failed since Paul Ehrenfest declared himself an atheist.

Sommerfeld offered him a position in Munich, but Ehrenfest received a better offer; at the same time there was an unexpected turn of events: H A Lorentz resigned his position at the University of Leiden, and on his advice, Ehrenfest was appointed as his successor.

In October 1912, Paul Ehrenfest arrived in Leiden, and on 4 December, he gave his inaugural lecture, Zur Krise der Lichtaether-Hypothese.

Paul Ehrenfest remained in Leiden for the rest of his career.

Paul Ehrenfest maintained close contact with prominent physicists in the country and abroad, and invited them to visit Leiden and give presentations in his lecture series.

Paul Ehrenfest was an outstanding debater, quick to point out weaknesses and summarize the essentials.

Paul Ehrenfest's classes were small, and he made an effort to get to know students who made use of the reading room.

Paul Ehrenfest was not merely the best teacher in our profession whom I have ever known; he was passionately preoccupied with the development and destiny of men, especially his students.

Paul Ehrenfest's assistants included Yuri Krutkov, Viktor Trkal, Adriaan Fokker, Paul Epstein, and Gregory Breit.

Paul Ehrenfest had ambivalent opinions about science, technological progress, and cultural and social issues.

Paul Ehrenfest's publications are renowned for their lucidity and directness, and for solving paradoxes by providing clearer descriptions.

Paul Ehrenfest's method is best illustrated by what he wrote to Robert Oppenheimer in the summer of 1928, after Oppenheimer invited himself for an extended stay in Leiden:.

Paul Ehrenfest made major contributions to quantum physics, including the theory of phase transitions and the Ehrenfest theorem, which states that expectation values of a quantum system conform to classical mechanics.

Paul Ehrenfest's name is given to the Ehrenfest paradox, an apparent paradox of relativity still discussed, to the Ehrenfest model, and to Ehrenfest time, the time characterizing the difference of quantum dynamics for observables from classical dynamics.