Galison: My question is not how different scientific communities pass like ships in the night,'' he wrote in Image and Logic. ''It is rather how, given the extraordinary diversity of the participants in physics -- cryogenic engineers, radio chemists, algebraic topologists, prototype tinkerers, computer wizards, quantum field theorists -- they speak to each other at all."
Let me add my own little anecdote to Galison's observation. Years ago I was interviewed for an assistant professorship at Columbia (I ended up at Yale, but that's another story). After meeting T.D. Lee in his dilapidated office, I got a tour of Norman Christ's lab downstairs. Christ was originally a quantum field theorist. One of his early papers, on classical Yang-Mills solutions in Minkowski space, the index theorem, and anomaly nonconservation, had a big influence on my research at the time.
But Christ had turned away from formal theory to the use of supercomputers to solve quantum chromodynamics (QCD) in so-called lattice Monte Carlo simulations. In his lab he had built one of the fastest supercomputers in the world, specially designed to handle the 3x3 matrices that occur in QCD. I was impressed to see a workstation used for chip design (VLSI) in the corner of the lab, and to learn that many of the PhD students he trained ended up as chip designers at IBM or Intel.
I asked him about the decision to change fields. Christ smiled at me with a gleam in his eye and told me that physicists have always invented every tool they needed. He sniffed at scientists in other fields waiting for the development of x-ray microscopes or lasers or fast computers. Physicists would continue to build whatever they needed to make progress!