Albert Einstein acquired Swiss citizenship in 1901, which he kept for the rest of his life. In 1905, he was awarded a PhD by the University of Zurich. The same year, he published four groundbreaking papers during his renowned "annus mirabilis" (miracle year) which brought him to the notice of the academic world at the age of 26. Einstein taught theoretical physics at Zurich between 1912 and 1914 before he left for Berlin, where he was elected to the Prussian Academy of Sciences. In 1933, while Einstein was visiting the United States, Adolf Hitler came to power. Because of his Jewish background,
Hans Albert Einstein recognition for more than twenty years of devoted and distinguished service to Applied Mechanics Reviews by the American Society of Mechanical Engineers (1972). In 1927 Hans Albert Einstein married Frieda Knecht. Albert disapproved of Frieda much as his parents had of Mileva. Einstein and Frieda had four children: Frieda died in 1958, and Hans Albert later married neurochemist Elizabeth Roboz (1904–1995). Einstein was an avid sailor, frequently taking colleagues and family out for excursions on the San Francisco Bay. On his many field trips and academic excursions, he took thousands of pictures, many of which he developed himself and presented