Physicist Luis Alvarez, 77, Nobel Prize Winner, Dies

Luis W. Alvarez, who won the 1968 Nobel Prize in physics for his work on the fundamental particles of the universe, but who became much better known for his controversial theory that the dinosaurs became extinct after an asteroid collided with Earth, died Wednesday night at the age of 77.

His wife, Janet, said his health had been in decline since he underwent surgery last fall for a benign brain tumor. After the surgery, he developed cancer of the esophagus. His death was caused by complications of a series of operations to treat the cancer, according to officials at the Lawrence Berkeley Laboratory, where Alvarez spent most of his professional career.

“Luis Alvarez was a stunningly creative individual,” said Lawrence Berkeley Laboratory Director David A. Shirley. “His discoveries and inventions spanned an amazing range of the frontiers of man’s knowledge over more than half a century. . . . He will be sorely missed and long remembered by his colleagues and proteges.”

When Alvarez began his career in physics in 1936, scientists thought there were only three fundamental particles--the proton, the neutron and the electron. Alvarez and others shattered this notion by showing that these so-called fundamental particles could themselves be shattered into much smaller particles, a veritable “zoo” of exotic particles with names like leptons, quarks and muons.

One of the primary thrusts of physics today is the use of ever more massive and expensive particle accelerators to develop a better understanding of these simple particles that Alvarez and his contemporaries discovered using primitive particle accelerators and “bubble chambers.”

The latter, refined by Alvarez, were tanks of liquid hydrogen with a viewing window. As high-energy particles produced by accelerators or cosmic rays passed through the liquid hydrogen, they left characteristic trails of bubbles that allowed their identification. Collisions between particles within the chambers also created new particles, whose characteristics could also be inferred by their bubble trails.

At the beginning of World War II, Alvarez went temporarily to the Massachusetts Institute of Technology, where he developed an electronic ground approach system used to guide planes into airfields. The system, known as GCA, was used by flight controllers to guide pilots in landings made in the dark or under adverse conditions. It also made possible the high density of landings necessary for the Berlin Airlift after the war.

Work on Atomic Bomb

He also invented a super-accurate high-altitude bombing system and a radar early-warning system before transferring to Los Alamos, N. M., in 1943 to work on the Manhattan Project, which developed the atomic bomb.

Alvarez invented the detonators that were used to set off the bombs and flew as an observer in the B-29s that dropped the devices on Hiroshima and Nagasaki.

At the war’s end, he returned to Berkeley and developed a variety of “atom smashers,” including one now called the Alvarez Linear Accelerator, as well as the tandem version of the Van de Graaf accelerator. He also developed new high-speed techniques for analysis of the data produced by nuclear collisions in the bubble chambers.

Alvarez received the 1968 Nobel for his “decisive contributions to elementary particle physics, particularly his discovery of a large number of (particles), made possible through his development of the technique of using hydrogen bubble chamber and data analysis.” But his fertile mind was not content to study only high-energy physics. In his spare time, in the early 1970s, he X-rayed Chephren’s pyramid in Egypt using only natural cosmic radiation, but was disappointed to find no hidden chambers inside. He lent his expertise to the Warren Commission’s study of the John F. Kennedy assassination, demonstrating through elementary physics that it could have been accomplished by a single gunman.

He also founded two successful companies that specialize in making clever optical devices. Among other things, he developed a gyroscopic stabilizer that makes it easier to use optical devices such as binoculars in aircraft and a range-finder for golfers.

Controversial Theory

But his name today is perhaps most often associated with the highly publicized, controversial theory, developed in 1980 with his geologist son, Walter, that the extinction of the dinosaurs 65 million years ago was caused by the collision of a massive asteroid with the Earth.

Such a collision, they postulated, would have spread massive amounts of dust and smoke throughout the Earth’s atmosphere, creating a miniature ice age that killed off plants and thereby destroyed the dinosaurs and many other species that fed on the plants. That theory was the progenitor of the concept of a “nuclear winter” that would be caused by an atomic war.

The father and son based their theory on their discovery of a thin layer of iridium, an element found in abundance only in comets and asteroids, in sediments laid down 65 million years ago. While most scientists now agree that a celestial body did strike the Earth then, the theory that it was responsible for the dinosaurs’ demise has been the subject of a vociferous dispute, complete with much unscientific name-calling, between the Alvarezes and paleobiologists who favor less dramatic explanations.

Alvarez was born in San Francisco in 1911, the son of Walter C. Alvarez, the famous Mayo Clinic physician and medical columnist. He planned a career in chemistry until he achieved a string of seven straight Bs in chemistry courses at the University of Chicago. Because he considered the grades unsatisfactory, he changed his major to physics. In less than a year, he had published his first scholarly paper.

Sister’s Influence

When he received his doctorate from Chicago in 1936, his sister was a secretary to physicist Ernest Lawrence in Berkeley and arranged for him to receive a $1,000-a-year research assistantship there. Except for the war years, he never left.

Alvarez credited the war with bringing prominence to physics, a field that previously was unknown to most people.

Before then, he said, “If I went to a party, I always said I was a chemist because nobody knew what a physicist was.”

Alvarez was an avid flier who owned a plane and flew several times a week. He included the Collier Air Trophy among his awards. He also golfed weekly, shooting in the 80s, and spent much of his spare time inventing devices to help other golfers and fliers. He was also a great booster of UC Berkeley, according to Chancellor Ira M. Heyman, and a football fan who rarely missed home games.

He served throughout his life on dozens of government committees, the most prominent of which was the President’s Science Advisory Committee. Recently he was appointed by President Reagan to serve on the National Commission on Space.

His autobiography, “Alvarez, Adventures of a Physicist,” was published last year. Many of his papers also were published last year by the University of Chicago Press under the title of “Discovering Alvarez.”

He is survived by his wife, Janet Landis Alvarez, four children, two sisters and a brother.