The German physicist, philosopher and peace researcher Carl Friedrich von Weizsäcker has died on 28th April at the age of 94. The brother of former German president Richard von Weizsäcker was born on 28th June 1912.
Carl Friedrich von Weizsäcker studied physics under Werner Heisenberg and Niels Bohr. Working with Hans Bethe in nuclear physics, he discovered the Bethe-Weizsäcker formula for nuclear masses and the Bethe-Weizsäcker cycle of nuclear fusion that powers the heavy stars. He also developed a model for the evolution of the solar system.
During the Second World War, von Weizsäcker was a member of the elite team of German physicists working on the unsuccessful attempt to develop a nuclear weapon for Nazi Germany; later, von Weizsäcker always maintained that the failure of that project was due to the physicists' unwillingness to develop such a devastating weapon for the Nazis, rather than a lack of ability to do so.
After the war, von Weizsäcker was a prominent opponent of plans for the nuclear armament of West Germany, signing the declaration of the Göttingen Eighteen that publicly exposed and rejected defence minister Franz-Josef Strauß's plan to arm the newly refounded German Army (Bundeswehr) with tactical nuclear weapons, and that created enough public opposition to end those plans once and for all.
Carl Friedrich von Weizsäcker's opposition to nuclear weapons and his interest in the responsibility of scientists for the use of their research led him into peace research, and to founding and directing the Max-Planck-Institute for research into living conditions in a scientific-technical world. He also worked as a philosopher, trying to unify all of physics into a coherent system of Natural Philosophy based on the idea of the quantum dynamics of primal logical alternatives (Uralternativen) underlying physical reality.