Morton F. Kaplon, groundbreaking physicist and teacher, died Thursday, July 4. He was 81.

Kaplon, chair of the Department of Physics and Astronomy from 1964 to 1969, and Class of 1951 doctoral graduate of the University, was internationally known for his discoveries in cosmic radiation, elementary particles, and ultra-high energy interactions.

While still a graduate student, he co-discovered the "R-Star" (Rochester Star), which provided the first clear evidence of the production of a large number of mesons in nuclear collisions at the top of the earth's atmosphere. Kaplon lifted special Kodak photographic plates in a balloon to 100,000 feet to catch a glimpse of a very specific kind of particle collision that was theorized to occur in the upper atmosphere. The collisions left star-like images on the plate (hence the name, "R-Star") with a very specific pattern that provided the first evidence for a new particle called the neutral pi-meson (now called the neutral pion).

Kaplon went on to make the first measurement of the life of a neutral meson, which was the shortest of any elementary nuclear particle observed at the time.

As a teacher, Kaplon helped shape the minds of many promising students, including Masatoshi Koshiba, who was recently awarded the Wolf Prize for "achievements in the interest of mankind," and has since been nominated for the Nobel Prize as well.

Born in Philadelphia, Kaplon served as first lieutenant in the U.S. Army Air Corps, Pacific Theater, from 1941 to 1946. He earned both his bachelor's and master's degrees in physics from Lehigh University before gaining his doctorate from the University of Rochester. After receiving his doctorate, Kaplon remained with the University for 23 years.

Kaplon died at St. Luke's Hospital, Fountain Hill, near his home in Bethlehem, Pa. He is survived by his wife of 56 years, Anita H. Kaplon; son, Keith of New York City; daughters, Bryna and Drea of New Jersey.

Contributions are being accepted at Kaplon's favorite charity, the Salvation Army.