AN EINSTEIN CHRONOLOGY 523
Early in the year, J J. Laub becomes E.'s first scientific collaborator.
They publish two joint papers.
December 21. Maja receives the PhD degree in Romance languages
magna cum laude from the University of Bern.
1909 March and October. E. completes two papers, each of which contains a con-
jecture on the theory of blackbody radiation. In modern terms, these two
conjectures are complementarity, and the correspondence principle. The
October paper is presented at a conference in Salzburg, the first physics
conference E. attended.
July 6. E. submits his resignation (effective October 15) to the patent
office. He also resigns from his Privatdozent position.
July 8. E. receives his first doctorate honoris causa, at the University of
Geneva.*
October 15. E. starts work as associate professor at the University of
Zurich with a beginning salary of SF 4500/annum.
1910 March. Maja marries Paul Winteler, son of Jost Winteler.
July 28. Birth of E.'s second son, Eduard ('Tede' or 'Tedel,' d. 1965 in
psychiatric hospital Burgholzli).
October. E. completes a paper on critical opalescence, his last major work
in classical statistical physics.
1911 Emperor Franz Joseph signs a decree appointing E. full professor at the
Karl-Ferdinand University in Prague, effective April 1.
March. E. moves to Prague.
June. E. recognizes that the bending of light should be experimentally
detectable during a total solar eclipse. He predicts an effect of 0".83 for the
deflection of a light ray passing the sun (half the correct answer).
October 30-November 3: the first Solvay Conference. E. gives the con-
cluding address, 'The Current Status of the Problem of Specific Heats.'
1912 Early February. E. is appointed professor at the ETH.
August. E. moves back to Zurich.
1912-13 E. collaborates with Grossmann (now professor of mathematics at the
ETH) on the foundations of the general theory of relativity. Gravitation is
described for the first time by the metric tensor. They believe that they have
shown that the equations of the gravitational field cannot be generally
covariant.
1913 Spring. Planck and Nernst visit E. in Zurich to sound him out about coming
to Berlin. The offer consists of a research position under the aegis of the
Prussian Academy of Sciences, a professorship without teaching obligations
at the University of Berlin, and the directorship of the (yet to be established)
Kaiser Wilhelm Institute for Physics.
June 12. Planck, Nernst, Rubens, and Warburg formally propose E. for
membership in the Prussian Academy in Berlin.*In later years, Einstein also received honorary degrees from Zurich, Rostock, Madrid, Brussels,
Buenos Aires, the Sorbonne, London, Oxford, Cambridge, Glasgow, Leeds, Manchester, Harvard,
Princeton, New York State at Albany, and Yeshiva. This list is most probably incomplete.