In Berlin in 1933, Fritz London was building quantum physics with Erwin Schrödinger. Hitler's rise to power and the enactment of anti-Semitic laws forced him to flee to Oxford and then Paris, where he arrived in September 1936. There, he met another physicist, Laszlo Tisza, who was fleeing political persecution in Hungary. Tisza and Tisza's collaboration at the Institut Henri Poincaré and the Collège de France respectively led to a major discovery: quantum physics not only explains the microscopic structure of atoms. It is visible to the naked eye, governing, for example, the macroscopic properties of a liter of liquid helium at low temperature.
A number of scientists associated with the Front Populaire and the "Comité d'accueil et d'organisation du travail des savants étrangers" (Committee for the Reception and Organization of the Work of Foreign Scientists) (Paul Langevin, Jean Perrin, Edmond Bauer, Louis Rapkine, Frédéric and Irène Joliot-Curie, Jacques Hadamard and his daughter Jacqueline...) were instrumental in bringing the two refugees together in France, as well as their new exile in the United States - London in September 1939, Tisza in March 1941.
The story of this meeting and discovery illustrates the conditions under which the lives of these very special emigrants - leading scientists - were saved in France, England and the United States. We will see that the defense of human rights joined the war effort of the Western Allies, since many of the refugee scientists were recruited to develop the atomic bomb before the Nazis.
