Alvarez, Luis Walter: 1911-1988: Nuclear Physicist, Inventor, Educator

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Luis Walter Alvarez: 1911-1988: Nuclear physicist, inventor, educator

One of the most versatile scientists and inventors of the 20th century, Luis Walter Alvarez used his expertise to impact optics, flight, warfare, and the tracking and measurement of subatomic particles. During World War II, he joined the Manhattan Project to further the creation of the atomic bomb. Upon return to research and teaching, he created a bubble chamber for studying subatomic particles, a device that won him the 1968 Nobel Prize in physics. Always committed to problem-solving, Alvarez also investigated the construction of the Egyptian pyramid of Kefren and proposed a theory explaining the extinction of dinosaurs 65 million years ago from the collision of a meteorite or comet with Earth.

Early Laboratory Experience

As a child, Alvarez gained valuable experience wiring electrical circuits while working in the shop of his father, Dr. Walter Clement Alvarez, a medical researcher in physiology at the University of California at San Francisco. When the family moved to Rochester, Minnesota, Luis Alvarez attended Rochester High School and apprenticed under a machinist at the instrument workshop at the Mayo Clinic, where his father was employed. In Alvarez's junior year at the University of Chicago, he changed majors from organic chemistry to physics, the source of his interest in optics. While taking twelve physics courses in five quarters, he worked with technicians in the optical lab of Albert Michelson and, on his own, devoured Michelson's articles. Alvarez's first published paper explained how to measure light wavelength using a lamp, phonograph record, and yardstick. By studying Hans Geiger's writings, Alvarez built one of America's first Geiger counters, a device to measure radioactivity.

Although Alvarez later criticized his basic education in the sciences, he appreciated having Nobel Laureate Arthur Compton for a mentor and learned on his own to build with glass and metal. Richard L. Garwin, who published a tribute to Alvarez's career in a 1987 issue of Physics Today, quoted Alvarez's version of how he learned to work independently by reading primary source materials: "I had the enormous self-confidence to be expected of a Robinson Crusoe who had spent three years on a desert island. I had browsed the library so thoroughly that I knew where to find the books I needed to learn almost anything I wanted to know." His humble reflection omits the fact that, years later, he could recite data, journal issue, author, and page on which information appeared.

At a Glance . . .

Born Luis Walter Alvarez on June 13, 1911, in San Francisco, California; died August 31, 1988 in Berkeley, California; married Harriet S. Smyth (divorced); married Janet Landis; children: (with Smyth)Walter, (with Landis) Donald, Helen. Education: University of Chicago, B.S., physics, 1932, M.S.,1934, Ph.D., 1936.

Career: University of California, faculty member, 1936-78; MIT, 1940-43; radar research and development, MIT, radar research and development, 1944-45; University of California, Berkeley, professor of physics, 1945-78; Lawrence Radiation Laboratory, associate director, 1945-59; University of California, Berkeley, professor emeritus, 1978-88.

Memberships: American Physical Society, president, 1969; Institut D'Egypt, associate; National Academy of Scientists, National Academy of Engineering; American Physical Society, American Academy of Arts and Sciences; Phi Beta Kappa; Sigma Xi.

Awards: National Aeronautical Associations's Collier Air Trophy, 1946; Medal for Merit, 1948; the city of Philadelphia's John Scott Medal and Prize, 1953; California Scientist of the Year, 1960; Einstein medal, 1961; Pioneer Award, 1963; National Medal of Science, 1964; Michelson Award, 1965; Nobel Prize in Physics, 1968; National Inventors Hall of Fame, 1978; Dudley Wright Prize in Interdisciplinary Science, 1981; Rockwell Medal, 1986; Enrico Fermi Award, U. S. Energy Department, 1987; honorary doctorates from the University of Chicago, 1967, Carnegie Mellon University, 1968, Kenyon College, 1969, Notre Dame University, 1976, Ain Shams University, Cairo, 1979, and Pennsylvania College of Optometry, 1982.

At age 23 Alvarez mastered aviation with the same passion with which he tackled other new skills. After only three hours of dual instruction, he flew solo. His license was the beginning of a half century of flying. In 1936 he and his wife, Harriet S. Smyth Alvarez, settled in Berkeley, California and reared a son, Walter. For most of his life, Alvarez worked in the Radiation Laboratory, a university atmosphere that suited him. Before beginning any projects, he read all the library's holdings on the subject of nuclear physics and memorized the equipment layout of every lab drawer and cabinet shelf. One of his first contributions to the laboratory was the reclamation of a neglected cyclotron, a device that accelerates charged particles. Nurturing his curiosity were Monday evenings spent with Nobel Prize-winning physicist Ernest Orlando Lawrence at the journal club and a subsequent introduction to Hans Bethe's overviews of nuclear physics in Reviews of Modern Physics, which challenged Alvarez to disprove them.

Inventor and Researcher

Some of Alvarez's most significant contributions to physics were the process of K-electron capture, by which he discovered that nuclei gobble up their own electrons, and the development of the mercury vapor lamp, which produced a light wavelength that the U.S. Bureau of Standards adopted as its official measure of length. Among his breakthroughs was the discovery of the east-west effect of cosmic rays, which he and Arthur Compton studied while occupying the roof of Mexico City's Geneva Hotel with a Geiger telescope mounted on a wheelbarrow. In collaboration with Nobel Prize-winning physicist Felix Block of Stanford University, Alvarez produced slow-moving neutrons to determine their magnetic moment.

World War II placed Alvarez at an historic place and time and allowed him the opportunity to assist the war effort through research and invention. He introduced heavy-ion physics by identifying tritium, a radioactive form of hydrogen, and by deducing that helium-3 stabilized ordinary helium. In 1940 he developed radar systems for the U.S. military at the Massachusetts Institute of Technology radiation laboratory. He also developed a narrow radar beam to aid the landing of aircraft by a ground-based controller and produced Vixen, a system that diminished returning radar messages to convince German U-boat commanders that an attack plane was flying out of range. He created the Eagle high-altitude bombing system, a radar-guided means of sighting and dropping bombs on objects out of the pilot's range of vision. His microwave early-warning system solved the problem of sighting aircraft through fog, dust, or heavy cloud banks.

Two years before the end of World War II, as American scientists raced to outmaneuver the Germans in creating deadlier bombs, Alvarez joined the Manhattan Project, a team effort located at Los Alamos, New Mexico. His contribution was a detonator to set off the first plutonium bomb. During the initial atomic test at Alamogordo, New Mexico, on July 16, 1945, he flew with observers in a B-29 bomber. When the army dropped the "Fat Man" bomb on Hiroshima, Japan, on August 6, 1945, Alvarez observed from the B-29 that followed the bomber Enola Gay. The terrifying destruction of the unsuspecting city below alarmed Alvarez, but he maintained that the device was essential to end the war before Japan inflicted lasting harm on the United States. He also supported the creation of a hydrogen bomb to ensure national security.

A Professor Once More

After WWII, Alvarez returned to Berkeley to assume a full professorship and research high-energy nuclear physics. Applying the methods of Ernest Lawrence and Ernest Rutherford, he developed LINEAC, also called the Alvarez accelerator, which increased proton velocity. He tinkered with the mechanism until it became operational in 1947 and used it and the university's Bevatron to advance post-war physics. His advancement of nuclear physics distinguished Berkeley as a center of subatomic particle study. In the college laboratory, he constructed a synchrocyclotron, which boosted particulate speed to new levels.

After meeting with physicist Donald Glaser of the University of Michigan in 1953, Alvarez increased the capabilities of the first bubble chamber, a one-inch container of superheated ether in which observers could track the paths of subatomic particles. After replacing ether with liquid hydrogen, he invented equipment that recorded particle movements to within one billionth of a second. Within five years, he enlarged the bubble chamber to 72 inches and initiated its use in 1959, when he recorded a series of observations of baryons, mesons, and other minute particles in resonance states. As he worked on projects affecting national security, Alvarez received access to National Security Agency data, a trust that made him proud. His skillful problem-solving in the study of subatomic particles within cloud chambers earned him the 1968 Nobel Prize for physics, which he accepted in the company of his second wife, Janet Landis Alvarez, mother of their children, Donald and Helen. Sten von Friesen of the Swedish academy of Science credited Alvarez with opening paths to a whole field of discoveries in high-energy physics.

Alvarez applied highly theoretical research to unusual problems. He joined the Warren Commission in 1963 to establish that President John F. Kennedy was assassinated by a lone gunman rather than a team of shooters. In 1965 he aided paleontologists of an American and Egyptian expedition in a study of King Kefren's pyramid at Giza. By channeling subatomic particles called muons through the stone tomb, he deduced that there is no hidden burial chamber in the structure.

In 1980 Alvarez worked with his son, Walter, a professor of geology at the University of California Berkeley, to determine and explain the existence of an inch-deep sediment of iridium-laced clay on rocky hillsides in Italy.

The presence of the rare metal convinced the two scientists that an asteroid or comet deposited it after colliding with earth 65 million years ago. They theorized that the impact raised so thick a cloud of dust and smoke that it blocked out sunlight and lowered temperatures, causing plants to shrivel and herbivorous dinosaurs to die of starvation and extreme cold. They surmised that the event obliterated 70 percent of earth's species. Highly debated at first, the theory was eventually corroborated by scientists who located the Chiczulub crater in the Yucatan, Mexico. Good-humoredly, Alvarez tweaked paleontologists for missing the telltale layer and called them poor scientists more suited to stamp collecting.

A Lifetime of Useful Work

At his death from cancer in Berkeley on August 31, 1988, Alvarez left numerous discoveries and 22 patents, including a radio distance and direction indicator and the Tandem van de Graaff generator, a charge-altering electrostatic accelerator that was later produced commercially. He devised a color television system, a stabilizer for the binoculars and cameras marketed by Schwem Technologies, a variable-power lens for Polaroid and Humphrey Instruments, and President Dwight D. Eisenhower's personal indoor golf practice machine. He directed projects for Hewlett-Packard and served IBM's Science Advisory Committee. The Nobel-Prize winner's contributions to American science were profound, and his many awards reflect the appreciation of the scientific community in which he found his intellectual home.