The small world of science

M y recent contact with small worlds and degrees of separation caused me to examine my scientific lineage and seek for the connectivity within that domain. I found this to be a fascinating recreation, revealing the roots and shoots of 20-century science. I apologize that this is clearly a name-dropping exercise, but I make an effort to indicate the varied nature of the connections. The reader may decide whether this is a parlor game or an approach to the history of science. In my third term as an undergraduate, my physics instructor was Henry Margenau, who later became a mentor and friend. I still turn to three of his authored and coauthored books on my shelves. He had studied with Erwin Schroedinger, knew Werner Heisenberg, and had spent some time with Albert Einstein at the Institute for Advanced Study at Princeton. As a sophomore at college, I was thus two or three degrees of separation from that entire generation of physicists who had given us relativity and quantum mechanics. My links to the future of physics were being formed through my association with Murray Gell-Mann, my laboratory partner in sophomore physics lab. The next instructor to put me in contact with the classical world of science was Alois Kovarik, who taught a course in Modern Physics. (We students did not regard it as modern, as it stopped before quantum mechanics.) On the last day of class, Professor Kovarik showed us slides of himself with Marie Curie, Ernest Rutherford, James Chadwick, and many others. Kovarik had been one of the first to determine the age of the earth from thorium-lead and uranium-lead ratios in a variety of rocks. I remember his office filled with geological samples. By the time he retired, health physics had been developed and the technicians entering that office found their radioactivity counters were driven off-scale by the pitchblende and who knows what else. (All of which reminds me that Kovarik also knew Johannes Geiger.) Our professor also told us of Jean Baptiste Perrin, whose 1913 book Les Atomes I consider to be the extreme example of connectivity in science. Perrin demonstrated the atomicity of matter by showing 16 different experimental methods of determining Avogadro’s number, all in agreement. And there he is, only two degrees of separation from this student. By junior year I was studying philosophy with Filmer S. C. Northrop, who had obtained his Ph.D. at Harvard under the direction of Alfred North Whitehead and Lawrence Henderson. The former had coauthored Principia Mathematica with Bertrand Russell, and the latter was well known in physical chemistry for the Henderson-Hasselbach equation. So I was thus three degrees removed from Russell and HAROLD MOROWITZ