Theoretical physics is in trouble. At least that’s the impression you’d get from reading a spate of recent books on the continued failure to resolve the 80-year-old problem of unifying the classical and quantum worlds. The seeds of this problem were sewn eighty years ago when a dramatic revolution in physics reached a climax at the 1927 Solvay conference in Brussels. It’s the story of a rush to formalize quantum physics, the work of just a handful of men fired by ambition, philosophical...