After earning his PhD at Berkeley, Lay Nam Chang was a resident associate at
MIT from 1967 to 1969. He next held a postdoctoral fellowship at the Enrico Fermi Institute of the University of Chicago from 1969 to 1971. Lay Nam Chang served as an assistant professor of physics at the
University of Pennsylvania from 1971 to 1978. During his time at Penn, he was a visiting scientist at the
Niels Bohr Institute in
Copenhagen, Denmark (1974),
Stanford University, and the
Brookhaven National Laboratory (1976, 1978). In 1976, during his time at Penn, Chang wrote pioneering articles on the foundations of
string theory, in collaboration with Freydoon Mansouri of
Yale University. For several years he served as chair of the Physics Department at Virginia Tech. From 2002 to 2003, he served as the last dean of Virginia Tech's College of Arts and Science, which, following a restructuring, split into a College of Liberal Arts and Human Sciences, and a College of Science. Lay Nam Chang continued to publish research articles in theoretical physics during his years as a dean. In 2005, he published a study called, "Hydrogen-Atom Spectrum under a Minimal-Length Hypothesis," with Sandor Benczik, Djordje Minic, and Tatsu Takeuchi; while in 2013, he wrote an article with Zachary Lewis, Djordje Minic, and Tatsu Takeuchi entitled, "Is Quantum Gravity a Super-Quantum Theory?" ==Death and legacy==