In 1911 he emigrated with his wife Ruth Elisa Wendt to Argentina. There he worked at the geophysical and astronomical observatory in La Plata. Afterwards he obtained a leading position at a Physics Department in Buenos Aires. After accepting the Argentine nationality (with the Spanish first name variant "Jacobo Juan") he began to work in the Diplomatic service of Argentina. In 1947 he returned to Germany. In his new home town Freiburg he went into economic troubles and therefore sold a part of his correspondence with Einstein.[1][2][3]
Scientific Work
In 1905 he investigated cathode rays together with Wilhelm Wien. Afterwards he investigated some topics on special relativity and wrote in 1907 an important work on the optics of moving bodies. In 1908 he wrote several works together with Einstein on the basic electromagnetic equations, which was aimed to replace the four-dimensional formulation of the electrodynamics by Minkowski by a simpler, classical formulation. Both Laub and Einstein discounted the spacetime formalism as too complicated. However, it turned out that Minkowski's spacetime formalism was fundamental for the further development of special relativity. Laub also published some papers on relativistic effects within gases and in 1910 he wrote one of the first survey articles on relativity. Also in the following years Laub still wrote many scientific papers on different topics.
Einstein, A.; Laub, J. (1908), "Berichtigung zur Abhandlung: "Über die elektromagnetischen Grundgleichungen für bewegte Körper"", Annalen der Physik, 332 (11): 232, Bibcode:1908AnP...332..232E, doi:10.1002/andp.19083321115