Werner Heisenberg
Werner Karl Heisenberg (December 5, 1901 – February 1, 1976) was a celebrated physicist and Nobel laureate, one of the founders of quantum mechanics.
Quantum mechanics
As a student, he met Niels Bohr in Göttingen in 1922. A fruitful collaboration developed between the two.
He invented matrix mechanics, the first formalization of quantum mechanics in 1925. His uncertainty principle, discovered in 1927, states that the determination of both the position and momentum of a particle necessarily contains errors, the product of these being not less than a known constant. Together with Bohr, he would go on to formulate the Copenhagen interpretation of quantum mechanics.
He received the Nobel Prize in physics in 1932 "for the creation of quantum mechanics, the application of which has, inter alia, led to the discovery of the allotropic forms of hydrogen".
Work during the War
Nuclear fission was discovered in Germany in 1938. Heisenberg remained in Germany during World War II, working under the Nazi regime. He led Germany's nuclear weapon program, but the extent of his cooperation has been a subject of controversy.
He revealed the program's existence to Bohr at a conference in Copenhagen in September 1941. After the meeting, the lifelong friendship between Bohr and Heisenberg ended abruptly. Bohr later joined the Manhattan Project. Germany did not succeed in producing an atomic bomb.
It has been speculated that Heisenberg had moral qualms and tried to slow down the project. Heisenberg himself attempted to paint this picture after the war, and Thomas Power's book "Heisenberg's War" and Michael Frayn's play "Copenhagen" adopted this interpretation.
In February 2002, a letter written by Bohr to Heisenberg in 1957 (but never sent) emerged. In it, Bohr relates that Heisenberg, in their 1941 conversation, did not express any moral problems with the bomb making project, that Heisenberg had spent the past two years working almost exclusively on it, and that he was convinced that the atomic bomb would eventually decide the war. The context of this letter, however, was the publication of the journalist Robert Jungk's Brighter than a thousand suns, which painted Heisenberg as having single-handedly purposely derailing the German project. Jungk printed an excerpt from a personal letter from Heisenberg -- taken out of context -- to justify the claim (in the full letter, Heisenberg was more demure about whether he had taken a strong moral stance). Bohr was understandably flustered by this apparent claim as it did not match with his own perception of Heisenberg's war work at all.
Some historians of science take this as evidence that the previous interpretation of Heisenberg's resistance was wrong, but others have argued that Bohr profoundly misunderstood Heisenberg's intentions at the 1941 meeting, or an overly passionate reaction to Jungk's work. As a piece of evidence, it has had little effect on overall historical conclusions.
Looking back
He wrote a book called "The Part and The Whole" about his life, his friendship with Bohr, and the evolution of quantum physics.
"He lies somewhere here" has been his epitaph.
According to an apocryphal story, Heisenberg was asked what he would ask God, given the opportunity. His reply was: "When I meet God, I am going to ask him two questions: Why relativity? And why turbulence? I really believe he will have an answer for the first."
References
- James Glanz, "New Twist on Physicist's Role in Nazi Bomb". The New York Times, February 7, 2002.