As a member of a Resistance group during the Second World War he flew to the UK in a small plane as part of a dangerous mission and was able to provide British intelligence with invaluable information.
There he met up with Charles de Gaulle who named him Director of Research in the Forces navales françaises libres (the Navy of Free France).
With the group of nuclear physicists around Werner Heisenberg and Otto Hahn he did not succeed because Samuel Abraham Goudsmit arrived at Hechingen earlier.
From 1947 he became a scientific advisor to the French military on the subject of atomic energy, eventually taking over from Frédéric Joliot-Curie after the latter was dismissed for political reasons.
His professional reputation eventually became tarnished by his increased focus on less conventional subjects such as biomagnetism, dowsing and UFOs.