Another Visit with Wolfgang Pauli

Karl von Meyenn and Engelbert Schucking provided many interesting facts and anecdotes about Wolfgang Pauli, but their article is marred by negative and inaccurate remarks about P. A. M. Dirac.

The authors make the astonishing claim that Pauli and Werner Heisenberg dismissed Dirac as a mere formalist. I have no knowledge of Heisenberg’s views, but as a close associate of Victor Weisskopf for 48 years, I often heard that Pauli was deeply impressed, even intimidated, by Dirac’s powers. And Weisskopf was Pauli’s assistant at the time when they were focused on understanding Dirac’s successful prediction of antiparticles.

I yield to no one in my admiration for Pauli, but it is unacceptable to denigrate Dirac while celebrating Pauli’s enormous contributions. The authors say that, in creating the relativistic wave equation, “Dirac repeated Pauli’s trick” of doubling the number of components of the wavefunction to incorporate spin. The Pauli two-component equation was an elegant restatement of what was already known about incorporating spin, as can be seen in the earlier calculation of the hydrogen fine structure by Heisenberg and Pascual Jordan. The discovery of the Dirac equation was one of the greatest achievements in the history of physics.

The authors’ attribution of Enrico Fermi’s golden rule to Pauli is also miscast; it was Dirac who developed time-dependent perturbation theory, including this formula, to calculate radiative transitions with his other great invention, the quantized radiation field. More than 20 years later, Fermi, in his Chicago lectures, called the formula a golden rule, and many physicists, with their habitual disregard for history, have ever since attributed it to Fermi.