Before the war, Oppenheimer had spent part of each year teaching at California Institute of Technology (Caltech). Christy was one of Oppenheimer's Berkeley students who made the trip down to Pasadena, California, each year to continue studying with Oppenheimer. After the war, Oppenheimer decided that with his additional responsibilities he could no longer continue this arrangement. The head of the W. K. Kellogg Radiation Laboratory at Caltech, Charles Lauritsen therefore asked Oppenheimer for the name of a theoretical physicist that he would recommend as a replacement. Oppenheimer recommended Christy. Willy Fowler then approached Christy with an offer of a full-time position at Caltech at $5,400 per annum, and Christy accepted. He remained at Caltech for the rest of his academic career. The drawback to working at Caltech was that neither Lauritsen nor Fowler was a theoretical physicist, so a heavy workload fell on Christy. This was recognised by a pay raise to $10,000 per annum in 1954.