1901 — Ernest Orlando Lawrence born August 8 in Canton, South Dakota.

1922 — earns B.A. in chemistry, University of South Dakota.

1923 — earns M.A. in physics, University of Minnesota.

1925 — earns Ph.D. in physics, Yale University.

1928 — Lawrence, an assistant professor of physics at Yale, is recruited as associate professor by the University of California.

1929 — conceives the principle of the cyclotron.

1930 — at 29, becomes UC's youngest professor; his student Edlefsen builds a working model of the cyclotron, and Lawrence describes the principle to the National Academy of Sciences.

1931 — in August, his student Livingston's 11-inch version of the cyclotron accelerates protons to 1.1 million MeV; that month UC President Sproul gives Lawrence the former Civil Engineering Test Facility on campus ("a shack") for use as a radiation laboratory.

1932 — marries Mary "Molly" Blumer in New Haven, Connecticut, in May (eventually they have six children); cyclotrons are first used for actual research, including the acceleration of deuterium nuclei (hydrogen-2).

1933 — attends the distinguished Solvay Congress in Brussels, the only American invited that year and only the eighth ever; he announces that deuterons are unstable but later retracts this.

1934 — Lawrence's "fruitful error" regarding deuterium inspires Alvarez's unexpected discovery, using the 60-inch cyclotron, that tritium (hydrogen-3) is unstable but helium-3 is stable.

1935 — Lawrence's younger brother John, a medical doctor, joins the laboratory and initiates research in nuclear medicine.

1936 — the Radiation Laboratory is officially established within the UC Physics Department with Lawrence as director; in Italy, Segrè examines an "invaluable gift" of material irradiated by the 27-inch cyclotron and discovers the first artificial element, later named technetium.

1937 — Seaborg joins the Rad Lab and "puts the chemistry in nuclear chemistry."

1939 — Lawrence wins the Nobel Prize for the invention of the cyclotron and his work on artificial radioactivity.

1940 — using cyclotrons, Kamen and Ruben discover carbon-14; McMillan and Abelson discover neptunium; Seaborg, McMillan, Kennedy, and Wahl discover plutonium; the foundation of the 184-Inch Cyclotron is poured in a cow pasture above the UC campus.

1941 — the Radiation Laboratory turns to defense work.

1946 — the 184-Inch Cyclotron is completed as the Synchro-Cyclotron.

1947 — Calvin uses carbon-14 as tracer to study photosynthesis.

1948 — the 184-Inch Synchro-Cyclotron produces muons and pions artificially; Alvarez invents the proton linac.

1950 — Anger invents the scintillation camera ("Anger camera"); Lawrence and Alvarez establish a research facility at Livermore Naval Air Station to convert uranium to plutonium with proton linacs.

1952 — the Livermore site of the Radiation Laboratory is established as the nation's second weapons laboratory (later the Berkeley site excludes classified research).

1953 — Glaser, inspired by bubbles in a glass of beer, invents the bubble chamber and detects cosmic-ray muons.

1954 — the Bevatron is completed and Alvarez's liquid-hydrogen version of the bubble chamber is installed.

1955 — at the Bevatron Segrè, Chamberlain, and others discover the antiproton; many other subatomic particles are detected.

1957 — the SuperHILAC is commissioned for heavy-ion research.

1958 — Eisenhower assigns Lawrence as technical advisor to nuclear test-ban talks in Geneva; he attends despite illness, is rushed back to U.S. and is hospitalized at Stanford, where he dies of complications of colitis on August 27. UC Regents name the "Lawrence Radiation Laboratory" in his honor.