1895 - Moved to Switzerland
1897 - Enrolled in the mathematics and physics teaching diploma program at the Swiss Federal polytechnic school in Zürich
1900 - Graduated from the mathematics and physics teaching diploma program at the Swiss Federal polytechnic school
1901 - Became a Swiss citizen
1903 - Started a permanent position at the Swiss Patent Office in Bern
1905 - Awarded a PhD by the University of Zurich
1914 - Moved to Berlin to join the Prussian Academy of Sciences and the Humboldt University of Berlin
1917 - Became the director of the Kaiser Wilhelm Institute for Physics
1917 - Became a German citizen again
1933 - Settled in the United States
1940 - Became an American citizen