The ultraviolet catastrophe

Book Review: Planck – Driven by vision, Broken by war, by Brandon R Brown
This was the last of the books I picked up in the Libreria sale in January last year. Planck is one of the figures in the history of science who awkwardly straddles “classical” and modern physics. One of the most fundamental physical constants of nature bears his name, emerging from his work on black-body radiation, but he found quantum theory disturbing and even after encouraging Einstein’s early work on relativity he wondered whether it was going too far.

Brown’s biography takes an equally awkward chronology. Chapters are titled for events in Planck’s life between 1943 and 1945, but they trace back and forth across his entire life. This does not confuse the reader, but at the same time, I’m not sure any benefit really derives from it.

Brown described Planck’s ability to keep abreast of new developments across the physical sciences in such a time of transition, and his open-mindedness to new ideas. Solving the black-body radiation problem (the ultraviolet catastrophe is the more exciting name given to earlier failed theories) produced the revolutionary idea in 1900 that energy might exist in discrete quanta, rather than as a continuous quantity. For Planck this was just a mathematical necessity to provide a solution that fitted observations, offered without explanation or justification.

Yet Planck comes over as politically and socially conservative, and is regularly described as “Prussian” although he was born in Kiel. There is quite an amount of family tragedy with losses in childbirth and war, though as Brown notes, quite typical for Germans of this generation, and Planck, living well into his eighties, was something of an exception. Brown gives a sympathetic portrayal to his increasingly out-of-line views in the 1920s and 1930s as “German” science became explicitly anti-Semitic. (The notion that “mathematical” physics was worthless and incorrect, and associated with “Jewish” physics, seems bizarre. Yet, this book was written in 2015, before the rise of “alternative facts” and the dismissal of “experts” in our own time, which now makes these reality-denying ideas more contemporarily relevant and disturbing).

Planck, already of retirement age, chose to remain in Germany after 1933, believing that the Nazi regime would quickly pass and a more normal state of affairs would return. Yet he was also quite compliant with the regime; among the photographs in the book is one of Planck offering a lecture at a Swastika-draped podium. One of his sons was implicated (somewhat distantly) in the 1944 Operation Valkyrie plot to assassinate Hitler, and was later executed. Towards the end of the war, Planck was a refugee in his own land, and was fortunate to be taken into protective custody by an American military unit who snatched him from what was arguably the putative Soviet sector. It’s interesting to read about an example of what many politically indifferent Germans must have done in accommodating themselves to their circumstances.