Walter R. Johnson: Personal recollections and his early work

摘要

Walter R. JohnsonnMy personal story and acknowledgement ofWalter Johnsonncomes from the period 1952–1957 when we were both studentsnin Physics and Mathematics at the University of Michigan,AnnnArbor. He was ahead of me and my classmates by a year orntwo, and very wisely guided several of us to important coursesnoffered by the Applied Mathematics group that otherwise wencould well have passed up. I and my beginning graduate studentncolleagues often abandoned the usual study halls in favornof the smoky cafeteria den of the Michigan Union, where wenwould talk, smoke, and drink gallons of coffee, working on ourngraduate-studies notes and difficult assignments in Electricitynand Magnetism, Quantum Mechanics, and so forth. And thatnis where we increasingly found ourselves inWalter’s company.nHe was a very generous teacher even then, tutoring us again andnagain on the material that we were wrestling with. So we camento rely on him as our most excellent mentor. Our distractions innthat setting were many, as the Union had big black and whitenTV sets that drew big crowds to view the Kefauver hearings,nHUAC, and the Army–McCarthy hearings. Indeed, those werenthe days. ButWalter’s steady scholarship tended to keep the restnof us in line. For example, he got us to organize a study group tongive group theory seminars to each other from Wigner’s booknthat was then still in German; in the end, I think his work onnthis cost him more time than it saved him!nI heard that Walter had accepted a research position withnProfessor Otto Laporte, so he asked me to come see what wasngoing on in that laboratory. Leading up to his Ph.D. dissertation,nhe was working on shock wave experiments and wantednto show me what he called a “shock tube”, where there wasna brilliant flash of light that arose simply from violent shocknwave compression, not from any electrical discharge.Well, thisnfascinated me at the time and then became a dominant interestnof mine for the next fifteen years. Otto Laporte’s laboratory andnseveral others (Western Ontario, Harvard College Observatory,