This isn't primarily the standard form of a scientific biography. The book does, of course, mention Planck's science, but it doesn't focus on giving us an in-depth understanding of entropy, blackbody radiation and the emergence of the quantum. What we have here is a study of Planck as a human being, family man and conflicted nationalist who found the Nazi Party, with whom he reluctantly collaborated in, for instance, the removal of Jewish scientists from German academia, uncomfortable and unsophisticated bedfellows.
What the book does well - better than any other book on Planck that I have read - is fill in the detail of his family life, both the positive, loving side and the disasters that saw Planck lose his first wife and all four of the children they had together, from eldest son dying in the First World War to his favourite Erwin, killed by the Nazis for possible involvement in a plot to assassinate Hitler. We see a loving family, at odds with Planck's old-fashioned stiffness in public affairs. And Brown does not hold back from some of the oddity of that family life - the way, for instance, his son-in-law married one of Planck's daughters, then married her twin when the first daughter died (only for the twin to die too). Or what might now raise an eyebrow or two when Planck married his wife's niece soon after his first wife died.
However there are some issues with the approach. The science isn't particularly well explained, not helped by a tendency to overuse florid similes. Planck's letter to Hitler, trying to prevent his son's execution, for instance, is described as being 'like a pick to the mountainside, his best shot to halt a steep slide.' Although the writing style is mostly light and approachable (sometime a little too colloquial, such as in the irritating habit of using 'passed' instead of 'died') the readability of the book is reduced by the jumpiness of the timeline. The first three chapters focus on 1944, 1905 and 1943 respectively. As Brown continues, each chapter then tends to start in 1944, gradually heading towards Erwin, the son's execution, but then in the body of the chapter jumps around all over the place chronologically.
I understand the urge to avoid writing a biography steadily along the timeline, as this can seem a little dull. But this attempt goes too far the other way with far too much flashing back, forwards and for all I know sideways. It's bad enough in any biography, but where there's science involved such a fluid chronology makes it harder to follow the development of the scientific content. The approach just didn't work for me.
Overall, certainly very interesting on Planck as a character. I think his role in Nazi physics is best captured by putting it alongside others as we see in Philip Ball's Serving the Reich, though Brown does an excellent job of bringing out the inner struggle between Planck's powerful love of the Fatherland and the difficulties he had with what was happening around him and to Jewish friends like Einstein. However, I can't rate the book any higher for the reasons mentioned above.
Review by Brian Clegg