Joseph Carl Hafele papers, 1955-2014

Joseph Carl Hafele was an American physicist, known for the Hafele–Keating experiment. In 1971, Joseph C. Hafele and Richard E. Keating, an astronomer, tested Einstein's theory of general relativity by taking four caesium-beam atomic clocks aboard commercial airliners and flying twice around the world. First, they flew eastward, then westward, and compared the clocks in motion to stationary clocks at the United States Naval Observatory. When reunited, the three sets of clocks were found to disagree with one another, and their differences were consistent with the predictions of special and general relativity.

Joseph Carl Hafele was born on July 25, 1933, in Peoria, Illinois, the son of Carl Louis Hafele and Thelma Loeb Hafele. In 1951, after serving in the US Army, he attended the University of Illinois at Urbana-Champaign, receiving his BS in engineering physics in 1959 and his PhD in nuclear physics in 1962. He married Carol Hessling in 1958, and they had four daughters. After graduation in 1964, he worked at the Los Alamos National Laboratory, where he conducted research in particle physics. From 1966–1972, he was a physics faculty member at Washington University in St. Louis, Missouri. From 1972 until retirement in 1996, Hafele conducted some developments for Caterpillar Inc., lectured at Eureca College (1985–1991), was a visiting researcher for NASA at Langley AFB in Hampton, Virginia, and lectured at Christopher Newport University in Newport News, Virginia. After retirement Hafele and his wife, Carol, moved to Laramie, Wyoming, where he continued theoretical work on the interpretation of experiments that might indicate anomalies in relativity. Joseph C. Hafele passed away on November 15, 2014, at 81 years old.