Friday, October 9, 2009

Did Bohr keep thinking critically?

A widely circulated story (especially on the internet!, see here, for example) features an undergraduate student giving "creative" answers to a standard physics exam question about how to use a barometer to find the height of a building. The punch line is:
[The examiners] asked the student if he knew the standard answer to the question. “Of course,” he replied. “But I am fed up with high school and university teachers trying to tell me how to think.”

And the name of the student of this perhaps apocryphal story? Niels Bohr, the Danish physicist who won the Nobel Prize for his contributions to quantum theory.
On reflection, there is great irony here, because later in life, Bohr himself "told people how to think", in ways that I consider significantly impeded a range of endevours.

First, the Copenhagen interpretation of quantum mechanics, seems to have been accepted by physicists largely by the force of Bohr's status and personality, rather than by its scientific merits. This is chronicled by James T. Cushing in, Quantum Mechanics: Historical Contingency and the Copenhagen Hegemony.

Second, this "hegemony" led to a dismissal of Einstein's objections to quantum theory and slowed the development of theory and experiments to test the foundations of quantum physics. John S. Bell was a "rebel" who pursued implications of the Einstein, Podolsky, Rosen paradox alone in the 1960's. His work and Aspect's experiments in the early 1980's eventually led to the whole new field of quantum information and many new interpretations of quantum theory, including decoherence based approaches.

Third, Bohr made many highly speculative statements about the implications of quantum theory to other disciplines (including politics and religion) that were accepted uncritically and used inappropriately by some postmodernists. Mara Beller, has chronicled these excesses in a provocative Physics Today article "The Sokal Hoax: At Whom Are We Laughing?", and a book, Quantum Dialogue: the making of a revolution.

I thank Ben Myers and Kim Fabricus for bringing this anecdote to my attention.

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