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Otto Hahn

Otto Hahn (1879–1968) was a German chemist who was a pioneer in the field of radiochemistry. He is referred to as the father of nuclear chemistry. Working with Lise Meitner at the Kaiser Wilhelm Institute for Chemistry in the building that now bears their names, they discovered isotopes of the radioactive elements radium, thorium, protactinium and uranium. He also discovered the phenomena of atomic recoil and nuclear isomerism, and pioneered rubidium–strontium dating. In 1938, Hahn, Meitner, Otto Robert Frisch and Fritz Strassmann discovered nuclear fission, for which Hahn alone was awarded the 1944 Nobel Prize in Chemistry. He worked on the German nuclear program during World War II; at the end of the war he was arrested by the Allied forces and detained in Farm Hall. After the war, he became the founding president of the Max Planck Society and one of the most influential and respected citizens of post-war West Germany. (Full article...)

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Chester A. Arthur

Chester A. Arthur (October 5, 1829 – November 18, 1886) was the 21st president of the United States, serving from 1881 to 1885. He was a Republican from New York who previously served as the 20th vice president under President James A. Garfield. Assuming the presidency after Garfield's assassination, Arthur's presidency saw the largest expansion of the U.S. Navy, the end of the so-called "spoils system", and the implementation of harsher restrictions for migrants entering from abroad. Suffering from poor health, Arthur made only a limited effort to secure the Republican Party's nomination in 1884, and he retired at the end of his term. He has been described as one of the least memorable presidents in the history of the United States. This photograph by Abraham Bogardus shows Arthur around 1880.

Photograph credit: Abraham Bogardus; restored by Adam Cuerden

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