Einstein contributed more than any other scientist to the modern vision of physical reality. His theory of relativity is held as human thought of the highest quality. In 1894 Einstein's family moved to Milan and Einstein decided officially to relinquish his German citizenship in favour of Swiss. In 1895 Einstein failed an examination that would have allowed him to study for a diploma as an electrical engineer at Zurich. After attending secondary school at Aarau, Einstein returned (1896) to the Zurich Polytechnic, graduating (1900) as a secondary school teacher of mathematics and physics. He worked at the patent office in Bern from 1902 to 1909 and while