6.32 A&G•December2008•Vol.49

The end of World War II marked a special time. A massive scientific and techno-logical build up, driven by war-time urgency, had occurred. After the war many of the young people who had been caught up in the war went back to their interrupted studies at a time when work at the frontiers of atomic and nuclear physics had produced real machines. Both Don Osterbrock and Mike Seaton had been involved in active service and were part of the wave of returning youth. They were brought into similar academic environments where the physics was at least as important as the astron-omy. Although they did not meet for nearly 20 years, their collaboration, which began in the mid-1950s, changed the way we understand the emission produced by an ionized gas. Don Osterbrock was born and raised in Cin-ncinati, Ohio, a Midwestern town with a large German population. The son of a university professor, he picked up a love for learning and hard work from his parents and environment. Pearl Harbor, which marked the entry of the United States into World War II, occurred near the end of Don’s high-school years and he found himself in the US Army soon after graduation. His training as an air corps weather observer took him to the University of Chicago to do the first half of an undergraduate physics degree. He returned to Chicago after service in the Pacific to complete his undergraduate physics degree, where he was befriended by Enrico Fermi, who took an interest in his career. He then entered the Chicago astrophysics gradu-ate programme, where he did a PhD (1952) on mathematical properties of interstellar cloud