Mathematics and the wireless world
Résumé
One of the most remarkable technological developments of the 1920s was that of the vacuum tube. The crucial properties of the vacuum tube, as Balthasar Van der Pol pointed out with respect to the triode oscillator in 1920, stem from retention of nonlinear terms in the differential equation describing the circuit containing the triode. Solving the resulting equation, however, was a great challenge. My paper compares the techniques employed by Van der Pol, Alfred Liénard, and others to capture the behavior of vacuum tubes and other nonlinear oscillating systems in the 1920s.