(1911-1988) US physicist who led the research team that discovered the X0 subatomic particle 1959. He also made many other breakthroughs in fundamental physics, accelerators, and radar. He worked on the US atomic bomb for two years, at Chicago and at Los Alamos, New Mexico, during World War II. Nobel Prize 1968.
In 1980 Alvarez was responsible for the theory that dinosaurs disappeared because a meteorite crashed into Earth 70 million years ago, producing a dust cloud that blocked out the Sun for several years, causing dinosaurs and plants to die. The first half of the hypothesis is now widely accepted.
Alvarez was born in San Francisco and studied at Chicago. In 1945 he became professor at the University of California, working at the Lawrence Livermore Radiation Laboratory there 1954–59. During World War II he moved to the Massachusetts Institute of Technology, where he developed the VIXEN radar for the airborne detection of submarines, phased-array radars, and ground-controlled approach radar that enabled aircraft to land in conditions of poor visibility. He also participated in creating the atomic bomb dropped on Hiroshima, Japan.
Alvarez built the first practical linear accelerator and an accelerator for breeding plutonium, and invented the tandem electrostatic accelerator. He also devised, but never built, the microtron for accelerating electrons.
In 1953 Alvarez met Donald Glaser, inventor of the bubble-chamber detector for subatomic particles. Alvarez decided to build a much larger chamber than Glaser had used, and to fill it with liquid hydrogen. He also developed automatic scanning and measuring equipment whose output could be stored on punched cards and then analyzed using computers. Alvarez and co-workers used the bubble chamber to discover a large number of new short-lived particles, including the K (the first meson) and the w meson. These experimental findings were crucial in the development of the “eightfold way” model of elementary particles and, subsequently, the theory of quarks.