Talk about a busy man, I have trouble achieving anything let alone breaking new ground in a scientific field that often:
January 6: Second anniversary of marriage to Mileva Maric.
Early March: Begins to submit one-paragraph reviews of recent scientific papers on heat theory to the Beiblätter zu den Annalen der Physik — mainly summaries, with occasional critical remarks. By the end of the year 21 of these reviews were published.
March 14: His 26th birthday.
March 17: Sends Annalen der Physik his photoelectricity paper, “On a Heuristic Point of View concerning the Production and Transformation of Light.” Received March 18, published June 9.
May 14: First birthday of son, Hans Albert.
April 30: Submits his University of Zurich doctoral dissertation, “A New Determination of Molecular Dimensions.” (Published in 1906.)
May: Sends Annalen der Physik his Brownian Motion paper, “On the Movement of Small Particles Suspended in Stationary Liquids Required by the Molecular-Kinetic Theory of Heat.” Received May 11, published July 18.
Mid-May: Conceives special relativity theory (he later recalled that he sent the paper in for publication five or six weeks after the idea came to him).
June: Sends Annalen der Physik his special relativity theory paper, “On the Electrodynamics of Moving Bodies.” Received June 30, published 26 September.
July 27: Doctorate is approved unanimously by University of Zurich Philosophy II faculty (the degree was formally awarded January 15, 1906).
August: Sends Annalen der Physik his doctoral dissertation on size of molecules, received August 19, published with slight revisions February 8, 1906. This would become one of Einstein’s most frequently cited papers. It shows how to use fluid phenomena to determine Avogadro’s Number, which is related to the size of atoms (and for skeptics, their reality).
Late summer: Travels to Serbia with Mileva and their son, visiting friends and Mileva’s family.
September: Sends Annalen der Physik his mass-energy equivalence paper, “Does the Inertia of a Body Depend upon Its Energy Content?” Received September 27, published November 21. This paper contains the concept which would later be written E=mc².
October-November: Earns a little money by tutoring a student on electricity.
December: Sends Annalen der Physik another paper “On the Theory of Brownian Motion,” received December 19, published February 8, 1906. This paper improves and extends his mathematical development of the theory.