The January 2013 issue of Physics Today contained informative and enjoyable articles on Norman Ramsey’s separated oscillatory field method and its continuing impact on precision spectroscopy research (pages 25, 27, and 36). However, a photo on the cover may be misleading. The molecular-beam apparatus labeled as “1949” was actually constructed by Tom Gallagher (now at the University of Virginia) and me as part of our thesis projects done under Norman’s guidance at Harvard University in 1969–70.
Although originally designed for high-precision measurements of hyperfine structure in molecules, the apparatus was later used for a search for P- and T-violating effects in molecules.1 After Norman closed down his Harvard laboratory in the 1980s, the apparatus was transported to St. Olaf College in Minnesota, where Jim Cederberg, another Ramsey graduate student, used it for undergraduate research projects for more than 25 years. During that time, according to Jim’s website, more than 70 students worked with the apparatus to study the hyperfine structure of polar molecules; that work resulted in 16 published papers. A few years after Jim retired from St. Olaf, the apparatus was moved to Georgia’s Southern Polytechnic State University; under the direction of Lu Kang, it will, I hope, inspire another generation of students in the joys of atomic and molecular spectroscopy.
Not only does Norman’s intellectual legacy live on, but at least in this case, the physical apparatus itself continues to be productive after more than 40 years of active use.
