Learn More About Physics

American theoretical physicist Val Fitch won the Nobel Prize in physics in 1980. Fitch showed that the K-mesons resulting from proton collisions did not obey the absolute principle of symmetry.
Val Logsdon Fitch, born in 1923, American experimental physicist and Nobel Prize winner. Fitch is noted for his studies of subatomic particles and for the discovery that one of the elementary particles, the neutral K-meson (now called the kaon), does not always follow the principles of symmetry, which were once thought to be universal traits. For their discovery of the violations of fundamental symmetry principles in the decay of neutral K-meson particles, Fitch and American physicist James Watson Cronin together were awarded the 1980 Nobel Prize in physics.

Fitch was born on a cattle ranch in Cherry County, Nebraska. His career as a physicist began during World War II (1939-1945) when, as a United States soldier, he was stationed in Los Alamos, New Mexico, to work on the Manhattan Project to design and build the atomic bomb. He developed excellent research skills and worked with future Nobel Prize winners, although he still had to complete his undergraduate degree, which he did in 1948 at McGill University in Montréal, Québec, Canada. Fitch earned his Ph.D. degree in 1954 at Columbia University in New York City. That same year, he joined the faculty at Princeton University in New Jersey, where he remained throughout his career.

At Princeton, Fitch teamed with Cronin to explore the characteristics and behavior of subatomic particles. Until the 1950s physicists believed that there was perfect balance, or symmetry, between matter and antimatter. This symmetry was described as CP, both a balance of positive and negative electrical charges (C) and parity, or equality, between left-handed and right-handed orientation (P). Fitch and Cronin found that this is not always true. In 1964 they observed that on rare occasions, the decay of neutral K-meson particles violates CP symmetry. The scientists modified the CP symmetry principle and confirmed CPT (charge, parity, time-reversal) symmetry, where there is a balance between matter and antimatter moving forward and backward in time, respectively.

Fitch and Cronin's research forced physicists to reexamine a number of theories. In particular, their discovery may explain the formation of sufficient matter to create our universe following the theoretical explosion known as the big bang. Without the violation of CP symmetry, matter and antimatter would have canceled each other out, and the big bang would have produced only gamma radiation, not our known universe.