Val Fitch dies at 91; Nobel laureate studied matter, antimatter

Obituary: Val Fitch offered a partial explanation for why the universe is made of matter, not antimatter

Physicist Val Fitch was not a lawbreaker, but he is famous for broken laws.

In a classic 1960s series of experiments, Fitch and his Princeton University colleague James Cronin proved that one of the key laws of physics hitherto thought immutable — that matter and antimatter operate by the same set of rules — could sometimes be broken.

Their feat won them the 1980 Nobel Prize in physics and offered the first partial explanation for why we live in a universe made of normal matter instead of antimatter. According to conventional laws of physics, the equal amounts of matter and antimatter produced in the Big Bang that created the cosmos should have annihilated each other, leaving only a shower of gamma radiation.

The pair's findings suggested that, after the primeval explosion, antimatter could have decayed slightly more rapidly than matter, leaving behind the normal matter that constitutes the universe as we know it.

Fitch, 91, died Feb. 5 at his home in Princeton, N.J., according to an announcement from the university. No cause was given.

Fitch and Cronin's conclusion "is one of the most important in the 20th century to show the laws of physics actually change with time," said fellow physics Nobel laureate Samuel Ting of MIT.

It was "a very fundamental discovery, because what we see in the universe is only matter, and that helps explain why we don't have galaxies made of antimatter," said Princeton physicist Pierre Pirou.

Using the newly built Alternating Gradient Synchrotron accelerator at the Brookhaven National Laboratory on New York's Long Island and a special detector designed and built by Fitch, the Princeton duo were studying the decay of elementary particles called kaons, produced by the collision of protons. Kaons, made up of two different types of quarks, have a lifetime of only fractions of a second, but during that life they oscillate rapidly between kaons and their antimatter counterpart, antikaons.

According to the laws of physics as they were then understood, the transitions from kaon to antikaon and from antikaon to kaon should be identical. The particles should undergo the same number of transitions in each direction before they decayed.

To their surprise, however, Fitch and Cronin discovered that the transition from antikaon to kaon occurred about half a percent less frequently. This small deviation from the laws of physics was the beginning of understanding how only matter survived the Big Bang, but only the beginning. Even 50 years later, the preponderance of matter today "remains one of the profound mysteries of the early universe," said Princeton physicist A.J. Stewart Smith.

Fitch and Cronin's 1964 paper was not initially widely accepted, but subsequent experiments in other labs confirmed their unexpected findings.

Val Logsdon Fitch was born March 10, 1923, on a cattle ranch near the town of Merriman, Neb. His experiences on the ranch, according to his family, demonstrated an early propensity for making and repairing mechanical and electrical devices.

In his acceptance speech at the Nobel ceremony, Fitch conceded that "It is highly improbable, a priori, to begin life on a cattle ranch and then appear in Stockholm to receive the Nobel Prize in Physics. But it is much less improbable to me when I reflect on the good fortune I have had in the ambience provided by my parents, my family, my teachers, colleagues and students."

Fitch graduated from high school in 1940 and enrolled at Chadron State College in Nebraska but was drafted by the Army in 1943. He was sent to what is now the Los Alamos National Laboratory to work on the Manhattan Project for the development of the atomic bomb. He developed the timing devices that triggered the bomb and witnessed the first test detonation there.

Fitch's experiences at Los Alamos and interaction with famous nuclear physicists of the time convinced him that a knowledge of electronics was crucial to experimental physics, and after the war he enrolled at McGill University in Montreal to study electrical engineering, receiving his bachelor's degree in 1948. He entered graduate school at Columbia University, receiving a doctorate in physics in 1954, and then began his research at Princeton.

After his retirement, Fitch became active in social causes. He was a sponsor of the Coalition for Peace Action, which advocates global abolition of nuclear weapons and a halt to weapons trafficking. He joined with other Nobel laureates in 1999 to urge the Senate to approve the Comprehensive Test Ban Treaty; in 2000 to urge President Clinton not to deploy the antiballistic missile system, which they thought would not be effective; in 2001 to issue a call for environmental and social reform to achieve world peace; and in 2003 to oppose the U.S. going to war with Iraq without broad international support.

Fitch was fond of bonsai gardening, baking bread, playing Scrabble and sailing in Nova Scotia, which he did each summer.

Fitch's first wife, the former Elise Cunningham, who was a secretary in his laboratory during the Manhattan Project, died in 1972. He is survived by his wife of 39 years, the former Daisy Harper; his son; a stepson; two stepdaughters; eight grandchildren; two great-grandchildren; and a half-sister, Judi Fitch Singleton.

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