Our fundamental circuit limits work plus many discussions with Prof. Paul Penfield, Jr., helped me uncover the only time I was able to predict new physics, another thing one does not generally get to do too often in a career. I was working as a visiting senior researcher at Hitachi Central Labs in the western suburbs of Tokyo on superconducting transistors. These are really charge-controlled Josephson junctions. What I discovered was that if the gate charge controls the magnetic flux between the source and the drain, then passivity requires that the flux also control the gate voltage, which was a new concept. The paper is, Prediction of magnetic flux-controlled gate voltage in superconducting field-effect transistors.