Fermi was certainly the last man who knew everything about physics, the study of matter, energy, time, and their relationships—the way the physical world works. He knew everything about how the physical world worked across subdisciplines and across theory and experiment as far as physicists were able to know these things during his lifetime. Our knowledge has evolved since he died, shaped by theory and experiment in ways that would have delighted Fermi had he lived. Even so, for one person to master all the physics of his day was a unique achievement. We may never see another like him.
