During John Cahn’s remarkable career, materials science underwent a first-order phase transformation. Along with Mullins, Hilliard, Serkerka, Frank, Herring and others, materials science transformed from a mostly empirical discipline to a new one that embodies the rigor and richness of physics and mathematics. Cahn was a driving force for this paradigm shift.
The breadth of Cahn’s contributions is breathtaking. The depth of his contributions is remarkable. Several enduring papers from the earliest years of Cahn’s career set the stage for a lifetime of productive tangents: elasticity, crystallography, thermodynamics, kinetics, mathematics. These tangents led to delightful innovations in the interstices of several disciplines—and often with insights that were only possible because Cahn was the quintessential polymath.