|Fig. 1: Bohr (far left) and Einstein (third from left) with physicsts James Frank and Isador Rabi. (Source: Wikimedia Commons)|
Human capital flight is the term used to describe the movement of highly-skilled and highly-educated workers in and out of their respective countries.  Brain Drain is used to describe the costs of a country, or the losing of these highly-talented people, and brain gain is used to describe the gaining of the highly-talented people.  While there have been multiple brain drain occurrences over the course of history, one of the most famous instances occurred before and during World War II, caused by both the fear and destruction of the Nazis and because of their anti-Semitic agenda. Many educated and talented people emigrated Europe and found their way in the United States, where they could freely pursue their intellectual passions free of fear from the Nazi regime.
Among the many people involved in the WWII Brain Drain, there were also some famous physicists who came to the US to escape anti-Semitism. The most notable physicist to come to America during this time was Albert Einstein, who renounced his German citizenship in order to remain free in America.  After leaving Germany permanently at the age of 54, Einstein had already established himself as one of the world's great minds, and Germany's loss now became America's gain. Another physicist to exit Europe in the brain drain was Enrico Fermi, who left Italy in 1938 to avoid to new Jewish laws that affected his wife, Laura.  He had studied neutrons during his time in Europe, and he used this information to further his studies in America. Niels Bohr is another physicist who would not have moved to America had it not been for the rise of Nazi Germany. Already famous for his creation of the Bohr Model, Bohr, shown in Fig. 1 with other physicists, was forced to flee Denmark and eventually found himself working in Britain as a part of the nuclear weapons project.  While these are just three examples of people involved in the brain drain, there were countless great minds forced to leave Europe as part of the thousands of immigrants trying the escape the cruelty of the Nazis.
These three physicists had an enormous impact in their new countries, with all three of them directly aiding in the Manhattan Project and the development of a nuclear bomb that would help end the war that caused them to leave their respective homes. Albert Einstein, with his knowledge of what the Germans scientists were attempting to develop, wrote a letter to US President Franklin Roosevelt advising him to have the US begin research similar to that of the Germans regarding nuclear weaponry.  The ideas in the letter convinced Roosevelt, and eventually the Manhattan Project was founded to develop these nuclear weapons. Einstein, while stating his discomfort with the idea of using nuclear energy in the form of weaponry, believed that the defense of the Allied Forces was more important.  Enrico Fermi worked on the Manhattan Project as the head of the team that developed Chicago-Pile 1, the world's first nuclear reactor.  The reactor was huge; it contained 45,000 graphite blocks that had to be fueled by around five and a half tons of uranium metal.  Fermi spent his time after the war continuing to research nuclear topics. He died in 1954 and his memorialized in many ways, one of which through the element fermium, which is named after him.  Finally, Niels Bohr, who fled to Great Britain, was a part of the British mission to the Manhattan Project.  Bohr worked with many scientists on the project, acting as a leader of the younger researchers more so than being actively involved in the work himself. Bohr believed that the secrecy of the project should be shared with the Russians in order to speed up the process, but he was unable to convince British leaders of his ideas; he eventually returned to Copenhagen after the war and lived out the rest of his life studying there. 
© Brendan Beck. The author warrants that the work is the author's own and that Stanford University provided no input other than typesetting and referencing guidelines. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.
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 A. Yu. "The Inception of the Manhattan Project," Physics 241, Stanford University, Winter 2017.
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