Alvarez, Luis Walter
Luis Walter Alvarez, 1911–88, American physicist, b. San Francisco, grad. Univ. of Chicago, 1932, Ph.D. 1936. He was awarded the 1968 Nobel Prize in Physics for his discovery of a large number of residence states (subatomic particles that have very short lifetimes and that occur only in high-energy nuclear collisions), which was made possible through his development of the liquid-hydrogen bubble chamber (see particle detector). He also helped develop the ground-control approach system for aircraft in the 1940s and played an important part in the Manhattan Project, where he suggested the technique for detonating the implosion type of atomic bomb. A member of the National Inventor's Hall of Fame, Alvarez held the patents for more than 30 inventions, including three types of radar systems. His autobiography, Alvarez: Adventures of a Physicist, was published in 1987. He; his son, the geologist Walter Alvarez, 1940–, b. Berkeley, Calif.; and others proposed that unusually high levels of iridium at the boundary between Cretaceous and Tertiary rocks indicated a major meteor impact with the earth about 65 million years ago and that this might be the cause of the mass extinction of the dinosaurs.