Carl Friedrich von Weizsäcker

Carl Friedrich von Weizsäcker bigraphy, stories - German physicist

Carl Friedrich von Weizsäcker : biography

June 28, 1912 – 28 April 2007

Carl Friedrich Freiherr von Weizsäcker (June 28, 1912 – April 28, 2007) was a German physicist and philosopher. He was the longest-living member of the research team which performed nuclear research in Germany during the Second World War, under Werner Heisenberg’s leadership. There is ongoing debate as to whether he, and the other members of the team, actively and willingly pursued the development of a nuclear bomb for Germany during this time.

He was son of the diplomat Ernst von Weizsäcker, elder brother of the former German President Richard von Weizsäcker, father of the physicist and environmental researcher Ernst Ulrich von Weizsäcker, and father-in-law of the former General Secretary of the World Council of Churches Konrad Raiser.

Weizsäcker made important theoretical discoveries regarding energy production in stars from nuclear fusion processes. He also did influential theoretical work on planetary formation in the early Solar System.

In his late career, he focussed more on philosophical and ethical issues, and was awarded several international honors for his work in these areas.

Theory of ur-alternatives

Weizsäcker developed the theory of ur-alternatives (archetypal objects), publicized in his book Einheit der Natur (literal translation Oneness of Nature, 1971) and further developed through the 1990s. The theory axiomatically constructs quantum physics from the distinction between empirically observable, binary alternatives. Weizsäcker used his theory, a form of digital physics, to derive the 3-dimensionality of space and to estimate the entropy of a proton falling into a black hole.

Work on atomic weapons

As a theoretical physicist, Weizsäcker (and by his own estimate, 200 other physicists) had recognized immediately after nuclear fission had become known (cf. Otto Hahn) in 1938 that nuclear weapons could potentially be built. He discussed the upsetting implications in February 1938 with philosopher friend Georg Picht.

During World War II, Weizsäcker joined the German nuclear energy project, participating in efforts to construct an atomic bomb. As early as August 1939, Albert Einstein had warned U.S. President Franklin D. Roosevelt about this research and that: "… the son of the German Under-Secretary of State, von Weizsäcker, is attached to the Kaiser-Wilhelm-Institut in Berlin where some of the American work on uranium is now being repeated."

As a protégé of Werner Heisenberg, Weizsäcker was present at a crucial meeting at the Army Ordnance headquarters in Berlin on 17 September 1939, at which the German atomic weapons program was launched.John Cornwell, Hitler’s Scientists (Viking 2003), 232 Early during the war -possibly until 1942-, he had been hoping for political influence growing out of participation in a successful nuclear weapons project. In July 1940 he was co-author of a report to the Army on the possibility of "energy production" from refined uranium. The report also predicted the possibility of using plutonium for the same purpose including the production of a new type of explosives.Cornwell, Hitler’s Scientists, 235 During summer 1942 Weizsäcker filed a patent on a transportable "process to generate energy and neutrons by an explosion … e.g., a bomb". The patent application was found in the 1990s in Moscow.

Historians have been divided as to whether Heisenberg and his team were sincerely trying to construct a nuclear weapon, or whether their failure reflected a desire not to succeed because they did not want the Nazi regime to have such a weapon. This latter view, largely based on postwar interviews with Heisenberg and Weizsäcker, was put forward by Robert Jungk in his 1957 book Brighter Than a Thousand Suns. In a 1957 interview with the German weekly Der Spiegel, Weizsäcker frankly admitted to the scientific ambitions of those years "We wanted to know if chain reactions were possible. No matter what we would end up doing with our knowledge – we wanted to know."Der Spiegel, "…und führe uns nicht in Versuchung: Vom gespaltenen Atom zum gespaltenen Gewissen – Die Geschichte einer menschheitsgefährdenden Waffe (…and do not lead us into temptation: From the split atom to the split conscience – the history of a mankind-endangering weapon)", vol. 11(19) (Mai 8, 1957), p. 52 Only by "divine grace", Weizsäcker said, were they spared the temptation to build the bomb – grace, as the German war economy was unable to mobilize the necessary resources.