John Reppy

John David Reppy (born February 16, 1931) is a physicist and the John L. Wetherill Professor of Physics Emeritus at Cornell University. He studies the quantum properties of superfluids such as helium. His experiments demonstrated the first evidence of topological phase transitions in superfluids.

Reppy is also a notable rock climber of long standing. He established a number of widely known climbing routes particularly in the northeastern United States.