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Willard Libby

1908–1980 · 72 years Tier III

A Colorado farm boy who used the bomb's leftovers to date the past

Portrait of Willard Libby — Willy Pragher — 1974 — CC BY 3.0 de via Wikimedia Commons

Libby grew up on farms in Colorado and then California, the son of parents who worked the land, and started school in a two-room Colorado schoolhouse. He put himself through a Berkeley chemistry doctorate on radioactivity, finishing in 1933, and spent the 1930s in the physics building a reputation for sensitive, homemade Geiger counters. He volunteered for war work the day after Pearl Harbor, joining Harold Urey's uranium-enrichment group at Columbia, and spent three years chasing barrier materials that would let gaseous uranium hexafluoride pass through metal without corroding it. The plant his work helped design, K-25 in Tennessee, produced the enriched uranium that went into the Hiroshima bomb in August 1945. He was 36 when the war ended and had never worked on anything but weapons chemistry.

At the University of Chicago after the war, Libby built on a stranger's 1939 discovery — that cosmic rays striking the atmosphere continuously make a radioactive form of carbon — into a working theory that any once-living thing carries a fading clock in its own tissue. He tested the idea against tree rings and Egyptian artifacts of known age and published the method in 1946: measure the decay, read off how long ago the organism died. Archaeologists and geologists adopted radiocarbon dating almost immediately, and it remade both fields inside a decade. The Nobel committee gave him the 1960 Chemistry prize for it, alone, unusual for a technique so quickly built on other people's physics.

The same government that gave him a Nobel-worthy peacetime method also made him one of five commissioners of the Atomic Energy Commission in 1954, the only scientist on the panel, and there he spent his conservative political instincts on the wrong side of the record. He sided with Edward Teller over Robert Oppenheimer on building the hydrogen bomb, ran a secret 1953 study of fallout from atmospheric testing called Project Sunshine that stayed classified until 1956, and told the public for years that the radiation risk from weapons tests was smaller than a chest X-ray. He did not reverse that position until 1958, near the end of his term, when he began supporting limits on the very testing he had spent years defending.

Radiocarbon dating outgrew the controversy entirely and became one of the least contested tools in modern science, refined since Libby's death with mass spectrometry that can date a sample from a fraction of what he needed. His AEC record reads differently: Project Sunshine is remembered as an early case study in a government scientist minimizing public risk from nuclear testing, not as a footnote to the Nobel Prize. He spent his last two decades at UCLA, directing its geophysics institute through the Apollo years and starting one of the country's first environmental engineering programs, and died in 1980 of a blood clot after pneumonia. Sebastopol, California, where he went to high school, named a park after him.

Lifespan

15401700180019002030

Willard Libby's life against the full span of the corpus.

Notable works

K-25 gaseous diffusion barrier invention
Manhattan Project uranium-enrichment work at Columbia 1945
Radiocarbon dating discovery
Published theory and method at the University of Chicago 1946
Radiocarbon Dating book
Full scientific monograph on the method 1955
Project Sunshine other
Classified AEC study of radioactive fallout, kept secret until 1956 1953
UCLA Environmental Engineering program company
One of the first such programs in the country 1972

Life in brief

with age at each point

1933 aged ~25 Earns a Ph.D. in chemistry at UC Berkeley
December 8, 1941 aged 32 Volunteers for Manhattan Project uranium-enrichment work Joined Harold Urey's group at Columbia the day after Pearl Harbor.
August 6, 1945 aged 36 K-25 enriched uranium his group helped produce is used in the Hiroshima bomb
1946 aged ~38 Publishes the theory behind radiocarbon dating
1953 aged ~45 Launches the classified fallout study Project Sunshine
1954 aged ~46 Appointed to the Atomic Energy Commission by President Eisenhower
1960 aged ~52 Awarded the Nobel Prize in Chemistry
1962 aged ~54 Becomes director of UCLA's Institute of Geophysics and Planetary Physics
September 8, 1980 aged 71 Dies in Los Angeles of a pulmonary blood clot