Officer in the patent office (1900–1909)

Einstein’s wonder year 1905

While the other graduates from his year took up their posts at the Polytechnic Institute, Einstein tried unsuccessfully to gain a position as an assistant lecturer at various universities in Switzerland, Germany, the Netherlands and Italy. Nevertheless, the friendships he had made with his former fellow students continued beyond their studies, as is reflected in his correspondence with Jakob Ehrat, or rather Ehrat's mother. During the summer semester of 1901, Einstein had the opportunity to teach the Mathematics course at the Technical College in Winterthur for two months. He then went on to accept a post as a private tutor in Schaffhausen. However, he had been waiting for some time for a position at the Patent Office in Bern, for which Marcel Grossmann had recommended him, to be advertised. When a post at the Federal Office for Intellectual Property was announced in the "Bundesblatt" on 11 December 1901, Einstein did not hesitate to apply, and on 19 June 1902 he was appointed Technical Expert, III Class.

In 1899 Einstein had begun to apply for Swiss citizenship. On 21st February 1901 Einstein became officially a citizen of Switzerland.

The year 1905 became an "annus mirabilis" for Einstein. Altogether he wrote five significant works on three areas of application, namely on the reality and size of the atom, about photons and about the theory of special relativity. Four of these works are mentioned by him in a Download letter (PDF, 535 KB) to Conrad Habicht. The brilliant concept of special relativity occurred to Einstein in May 1905 in a discussion with Michele Besso in Berne. During the following six weeks he wrote his essay, which appeared three months later in the "Annalen der Physik” under the inconspicuous title of "Zur Elektrodynamik bewegter Körper" and which would revolutionise physics as well as the established ideas about space and time.

In 1907 Einstein had the first crucial idea about the theory of general relativity.