My early days in photobiology with Philip Hanawalt.

Phil and I started our careers on somewhat similar scientific paths. I had an undergraduate degree in physics from Swarthmore College and a Ph.D. degree in physics from Yale for research in the field for ultraviolet spectroscopy. Phil received an undergraduate degree in Physics from Oberlin College, joined the Yale Physics Department in 1954, and transferred to the new Biophysics Department in 1955. We began our interactions then by virtue of the fact that Phil had to take a Laboratory Course in Experimental Physics, one part of which was spectroscopy in which I was the instructor. One of my principal interests was in the effects of different wavelengths of ultraviolet (UV) radiation on proteins, viruses and bacterial cells. So what was more natural than for Phil to dream up a Ph.D. research project to investigate the effects of different wavelengths of UV on macromolecular synthesis in Escherichia coli. I became his mentor with expertise in UV, whereas he did most of the microbiological/biochemical work. Thus began a collaboration and a communicating friendship, the latter going on for 50 years. That communication was essential in elucidating some of the important steps in nucleotide excision repair-a field in which Phil is a pre-eminent scholar and investigator.