Prof. Emeritus Victor Barcilon, applied mathematician and geophysical scientist, died April 15. He was 81. A longtime professor at the University of Chicago, Barcilon showed a gift for using a type of mathematics called asymptotic analysis to improve understanding of the physical principles behind the world, from the mechanics of neurons to the behavior of oceans, glaciers and rock over time. “The basic laws of physics in their general primitive form are too hard to understand and solve in most natural phenomena,” wrote Prof. Douglas MacAyeal, a glaciologist in the Department of the Geophysical Sciences. “But with the gift of Victor’s deep, disciplined mathematical thinking, small physical understandings yield huge leaps and bounds of understanding (and forecast ability).”