In 1932, while the world at large was deep in the grips of an economic depression, those involved in the infinitely tiny worlds of quantum mechanics and nuclear physics were experiencing what would become known as their “miracle year.” With the discovery of the neutron, antimatter and the first artificially induced nuclear transmutations, physicists were on their way from the quantum revolution to the nuclear age. And they were having a whole lot of fun with it all.
Gino Segre’s Faust in Copenhagen: A Struggle for the Soul of Physics uses the annual meeting of physicists at Niels Bohr’s Copenhagen Institute as a framework for the story of the rise of quantum mechanics. In Copenhagen that year, the entertainment was a parody of Faust put on by the physicists. Faust was chosen due to the celebration of the centennial of Goethe’s death; later it became seen as a prescient choice that foreshadowed the deadly bargain that was struck by nuclear physicists—they had made discoveries that were tremendous, fascinating, even beautiful but that in time would be used to build instruments of destruction.
The main players in the world of quantum physics were used as characters in the play. Bohr, the beloved elder statesman of quantum physics, stood in for the Lord. Mephistopheles was the mischievous, sarcastic Wolfgang Pauli, who had long gleefully embraced his nickname, “the Scourge of God.” Einstein, estranged from the progress of these physicists and on his own path, was a cameo character. James Chadwick, who had just discovered the neutron was Wagner. The parody was mostly written by Max Delbruck, who later found his way into molecular biology. Audience members included Paul Dirac, Werner Heisenberg, and Lise Meitner. Paul Ehrenfest, a quiet, troubled Austrian, wasn’t a character himself, but played the role of Faust.
Segre keeps bouncing away from the Copenhagen meeting to tell about the lives and achievements of these physicists, most of whom had made their greatest discoveries in their early twenties. Pauli, for all his teasing and biting (sometimes mean) wit, was a careful and critical theoretician. Heisenberg was more daring, but had the talent and intellect to back up the leaps he was willing to take. Dirac had a quiet, unforced brilliance that gave his work grace.
These physicists, from the truly great to the students they inspired, are the heart of the story. Rather than isolated, cold lab rats, they come off as relentlessly collaborative—always writing to each other, proposing new ideas, arguing about others. Put them together and you get practical jokes, drinking, and theater.
Segre, a physicist himself and nephew of Emilio Segre, a Nobel Prize winner who started out working with Enrico Fermi, obviously has a great deal of affection for these scientists and the lives they lead. He describes the joy of seeing a professor surrounded by his students, now with their students, and those students’ new young followers; the moment when he, or any other physicist has an idea and quietly holds onto it for a few days or so, reveling in the joy of its potential before the real work must begin, and failure possibly follow.
Segre teaches at UPenn and it’s easy to imagine taking a class with him. He explains things in ways that even the scientifically uneducated (that would be me) can understand and that’s quite an achievement. The book jumps around from discovery to biography to Copenhagen, but it’s all logical and simple enough to follow.
The 1932 meeting was sort of a last hurrah for this moment in physics. Though other meetings took place throughout the 1930s, soon after the Faust Copenhagen, the physicists began to scatter, to escape the war. Einstein was already gone. Bohr would eventually get out and make his way to Los Alamos. Meitner, who went to Sweden would discover nuclear fission (though I use the word discover carelessly; to say that she and her nephew understood correctly the results of others work would be better, I think). Heisenberg stayed in Germany and became suspect on both sides, either for helping the German nuclear program or not trying hard enough. Pauli went to the Institute for Advanced Studies at Princeton, and then eventually to Zurich. Ehrenfest committed suicide not long after the 1932 meeting. The very young men who had formulated quantum mechanics suddenly found themselves the grown ups, no longer the rebels and rule breakers. Others came in to take up the next challenges. Physics seemed to be a young person’s game.
I always envy scientists and mathematicians, who are able to determine the worth of a solution in terms of beauty and elegance. How nice it must be to be able to see the world that way, but I don’t know how. There is something in an equation that they can see that I cannot, some kind of symmetry, some kind of line, some kind of grace… Dirac said:
“It was sort of an act of faith with us that any equation which describes fundamental laws of Nature must have great mathematical beauty in them. It was like a religion with us.”
And that is a beautiful idea. And I understand it, but I don’t see it, which, I think, is worse than not understanding.