Planck: Driven by Vision, Broken by Warby Brandon BrownOxford University Press, 2015The great physicist Max Planck was born in Kiel in 1858, raised in an intellectually thriving household, and attracted powerfully to the field of theoretical physics even as a young man at the University of Munich in the 1870s. He was named an associate professor of physics at the University of Kiel in 1885 and was a full professor at the University of Berlin by 1892. In 1918 he won the Nobel Prize for his work in theoretical physics, specifically his groundbreaking exploration of quantum mechanics, a discovery that equaled the work of his friend Albert Einstein on general relativity and entirely revolutionized science's understanding of the world.Planck adored his first wife, Marie, with whom he had four children. Marie died in 1909, and Planck outlived all four of their children, including his son Karl, who was killed at Verdun during the First World War, and his son Erwin, who was shot by the Gestapo in 1945. With his second wife, Marga, he endured the rise of National Socialism, the insanity of the Nazi years, and the chaos of Germany's military defeat (the Planck home in Berlin was destroyed in 1944). He died at Gottingen in 1947.As even so brief an outline makes clear, Max Planck's life was bounded on all sides by both incomprehensible intellectual pursuits and incomprehensible personal tragedies. That – and the destruction of virtually all his personal papers and effects in 1944 – makes him a tough sell for biographers. Planck was brave but practical; his fundamental belief in the believable was traumatized by his encounter with the seething insanity of the Nazis. He didn't flee the country when Hitler came to power; instead, the world's most famous physicist stayed at his post and urged his colleagues to do likewise, urgent that the light of science not go out in Germany. He was not a charismatic exile like Einstein, nor was he a charismatic martyr like Bonhoeffer – in this too, he thwarts summary.His latest biographer, physics professor Brandon Brown, is his best: searching, sympathetic, and technically informed. This last is of course crucial: any popular biography of Planck must spend a good deal of its time trying to explain his work - a hopeless task, but still. Like Einstein, Planck is associated with a deceptively simple-looking formula, E = hv, but unlike general relativity, the concept of quantum physics makes no intuitive sense. As Richard Feynman used to quip, the more you know about it the less you know about it.Brown tries heroically to overcome this. He's a very lively writer and a first-rate explainer (and in his own field, he compensates the dorkiness of being a physics professor by being a physics professor who studies sharks), but there's only so much that can be done with quantum physics and black-body radiation and entropy oscillations and cavity radiators. Einstein had adorable hair and conceptual simplicity (matter is energy, time is relative, and all that jazz); Planck had perhaps the most hangdog tragic face in the annals of physics (don't be fooled by the pretty 20-year-old dandy on the cover of Brown's book – the day that photo was taken was the last day Max Planck was ever happy) and was wreathed all around with hard-edged gibberish so abstruse he had to invent most of the vocabulary for it from scratch – hence Planck's constant, Planck mass, Planck length, etc. As a result, posters of Einstein adorn college undergraduate dorm rooms around the world. If you found a poster of Max Planck in an undergraduate's room, you'd be will within your rights to inform social services.Planck: Driven by Vision, Broken by War, bless its nerdy heart, tackles these problems head-on. Planck was one of the towering scientific figures of the 20^th century and one of the most pivotal scientific thinkers of all human history, and Brown isn't willing to let these achievements fall prey to the notorious scientific ignorance and incuriosity of modern-day American reading audiences. Instead, he works to clarify Planck's thinking at every stage of its evolution, and he gamely dramatizes the controversies Planck stirred up. Take just one example:

[Planck] aimed to show that no matter what kind of light might fill the cavity initially, that the activity of the resonators would eventually yield the observed black-body radiation. He wanted to uncover a one-way arrow of physics from any starting point to the final one, so that he could explain how any object would arrive at the same experimental output. But doubts began to encircle him in late 1897.“Any unidirectionality which Hr. Planck finds,” [Austrian physicist Ludwig] Boltzmann wrote in a devastating critique, “Must … derive from his choice of unidirectional initial conditions.” Boltzmann's point was that Planck's attempts to show a universal and unstoppable series of events were not universal at all. Boltzmann correctly detected that Planck's theory had hidden training wheels. It wasn't quite ready to balance on its own. Nature clearly could start anywhere and arrive at the same endpoint. But Planck's theory needed a carefully selected starting point or it tumbled over.

You might not have the first idea what Planck and Boltzmann were arguing about, but you can feel the calculated heat of the exchange, and that's to Brown's credit. Planck re-wrote science's basic understanding of reality; it's only right that Brown should make such consistently energetic attempts to show his readers how much that mattered to the handful of physicists who grasped its implications.For most readers, however, the drama of Planck's non-professional life will likely trump talk of electromagnetic variation, and here Brown the teacher yields to Brown the storyteller, with very pleasing effect. About the stupendous tragedies Planck endured, Brown is of course sympathetic (“Contemplating the gaping tragedy of losing a wife and four children is a bit like standing on the rim of Arizona's Grand Canyon; most of us cannot hope to really absorb or understand it”) (although this is accompanied by a bizarrely bloodless observation that, life expectancies being what they were in the late nineteenth century, the really odd thing wasn't that four of Planck's children died so early but that he himself died so late – one doubts Hallmark Cards will be scooping up that sentiment any time soon). But the real high point of his narrative involves Planck's dealings with the barbaric Nazi regime that took over the most culturally and scientifically advanced country on Earth and steadily began reverting it to the Middle Ages.Planck met with Hitler in May of 1933, confident that rationality, not mathematics, was the true universal language. In this spirit he mentioned to the Fuhrer that new antiSemitic regulations, if carried to their logical extreme, would end up depriving German institutions of some of their best scientists, and surely that wasn't what anybody wan- and it was around this point that Hitler started screaming and ranting and pacing and didn't stop even after Planck had quietly backed out of the room. “As Hitler raised his voice,” Brown demurely writes, “Planck watched his most reliable instrument, reasonable discourse, being unplugged and tossed aside. Maybe he even apologized for upsetting his host.”There followed a dreary rearguard action of grudging accommodation. As Brown writes, Planck “requested exceptions to Nazi policies, but he said his 'Heil Hitlers,' saluted when appropriate, and dismissed nineteen Jewish assistants at the [Kaiser Wilhelm Society].” It wasn't bold; it wasn't principled; it wanted nothing so much as for the Nazis to simply go away – and as Brown rightly notes, it's sparked debate for the last seventy years:

In acquiescing to Hitler, Planck inspired divided reactions in 1933 just as he does today. Some saw Planck taking his best available route to protect people and change the situation. But, as the science historian Michael Eckert points out, Planck was also probably reluctant to step away from his accustomed access to power.

“While many academics dislike authority,” Brown shrewdly notices, “it pulled on Planck like a magnet.” This is not a pleasant thing to admit about a great man, but alongside admitting it, Brown also portrays the scattered instances when Planck defied his own nature in order to make minor stands against the Nazis. The reader is left certain that if Planck had emigrated to the United States in the 1930s (perhaps taking a berth at Columbia, where he'd given a triumphant series of lectures twenty years before), his professional life would have been a great deal easier – and that it was after all an act of dogged bravery, rather than conservative inertia, for him to stay in a bad Germany hoping for a better Germany.In short, a very complex life, here given a fittingly complex study. Certainly a worthwhile thing to read alongside the next 35 biographies of Einstein to come down the pike (although the latest of these, Steven Gimbel's short entry biography for the “Jewish Lives” series from Yale University Press, is an absolute gem and not to be missed). And perhaps follow up reading about Planck by spending an utterly fruitless afternoon trying to grasp quantum theory? Brown's book might help a bit with that as well.