Saturday, May 14, 2011

Heisenberg Re-read

Some books you get acquainted with during school days you should absolutely re-read when being old and gray. Into this category, among many others, belong the Bible and Goethe's Faust. Up to now I didn't count Werner Heisenberg's The Part and the Whole (Published in an English translation titled rather commonplace: Physics and Beyond), a book that I read as a young physisist, among those but admittedly I was mistaken.

This year my annual bicycle tour will take me to Franconia. Wulf, a former classmate, retired College teacher for German and biology, organizes these yearly trips. He does a marvelous job not only in preparing these tours but while cycling during the day we learn about birds and plants along the way and for the evenings Wulf has prepared a reading choosing always an author and topic with relevance to the region we are cycling.

Apparently there are no famous regional authors connected with Würzburg but Werner Heisenberg, Nobel prize winner in physics, was born in this town in 1901. Since I had contributed to the evening entertainment on past bicycle tours too - although with mixed success - Wulf asked me whether I would be willing to read something written by Heisenberg. To this end I took his autobiography from the shelf and noticed it had been published in 1969 making it more than 40 years that I first read the book.

What is comprehension in physics? Are we satisfied with the understanding of a phenomenon when it is possible to describe it by a mathematical formalism? Although such an understanding will allow us to do calculations and hence make predictions the situation remains quite unsatisfactory. It turns out that terms and definitions of our daily experience will break down when we try to describe phenomena in the atomic world.

A cartoon by N. Harding showing Erwin Schrödinger clueless. His equation named after him allows to calculate discrete quantum states by using wave mechanics. 
One famous example is the physical description of light. Whilst Christiaan Huygens in the 17th Century forwarding the wave theory of light had beaten Isaac Newton's corpuscular theory modern physics eventually englobed both ideas and talks about a particle-wave duality. This is not a fight between scientists but an attempt to explain the physics of light with pictures taken from our everyday experience where we need both complementary descriptions. The problem of comprehension and that our language is incapable of describing the phenomena in atomic physics in an inherently consistent way is one of Heisenberg's leitmotifs. Following my 40 year experience in the subatomic world it is just fascinating to read his book again.

1 comment:

  1. Thankyou for pointing out that the book was translated as Physics and Beyond. The Wikipedia article on the book "The Part and the Whole" confuses the matter.

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