Donald A. Glaser

Physicist

• Born: September 21, 1926
• Birthplace: Cleveland, Ohio
• Died: February 28, 2013

During a career filled with diverse scientific achievements, Glaser invented the bubble chamber, which allowed scientists to observe high-energy beams of fundamental particles produced by particle accelerators.

Early Life

Born to William J. and Lena Glaser, Jewish emigrants to the United States from Russia, Donald A. Glaser (GLAY-zur) received his early education in the public schools of Cleveland Heights, Ohio, where he developed a love for science. He earned a bachelor’s degree in physics and mathematics from the Case Institute of Technology in 1946. His bachelor’s thesis was an electron diffraction study of the properties of thin metallic films evaporated onto crystalline metal substrates. In 1949, he completed his Ph.D. in physics at the California Institute of Technology. He officially received his degree in 1950. His doctoral thesis was an experimental study of the momentum spectrum of high-energy cosmic ray and mesons at sea level.

Glaser accepted a teaching and research faculty position at the University of Michigan in 1949, and he was promoted to full professor of physics in 1957. While at Michigan, Glaser worked on experiments associated with identifying the properties and the interactions of short-lived elementary particles known as strange particles. The most common tool used for tracking elementary particles at the time was the cloud chamber. Glaser’s graduate school experience had shown him that cloud chambers were inadequate for tracking strange particles. As the particles passed through a gas and collided with metal plates, the scientist’s view of the events was obscured.

Life’s Work

To overcome the problems associated with using cloud chambers, Glaser recognized that he needed a detector that contained a higher-density medium than the vapor in a cloud chamber. In the early 1950’s, he experimented with using superheated liquid in a glass chamber. High-energy elementary particles would leave a track of bubbles as they passed through the liquid. These tracks could be photographed. This led Glaser to his invention of the bubble chamber in 1952. He used ether as the working substance, and he showed that hydrogen would also work. The images he produced with his bubble chamber at Brookhaven National Laboratory in New York brought recognition for his invention and funding to produce larger chambers. The bubble chamber allowed physicists to observe what happens to high-energy beams of particles produced by high-energy accelerators.

In 1959, Glaser accepted a position as a professor of physics at the University of California, Berkeley (UCB). He worked on improvements to his bubble chamber by varying the liquid used in the chamber and the effects of using containers of varying shape and size. Along with Nobel laureate Luis Alvarez, he worked on the development of a hydrogen bubble chamber at UCB. Glaser conducted experiments in high-energy nuclear physics and determined lifetimes, decay modes, and spins for the neutral lambda hyperon, the neutral K-meson, and the neutral sigma hyperon as well as differential cross-sections for their production by pions. Other experiments provided information about pion-proton scattering, parity violation in nonleptonic hyperon decay, and the branching ratios in positive K-meson decay.

In 1962, Glaser changed his research focus to molecular biology. He studied the control of deoxyribonucleic acid (DNA) synthesis in bacteria and human skin cancer induced by ultraviolet radiation. In 1964, he added professor of molecular biology to his title at UCB. In 1971, Glaser and three friends cofounded Cetus Corporation, the first biotechnology company, to bring the results of microbiology research to applications in medicine and agriculture. Glaser then turned his talents to neurobiological research, particularly associated with the human visual system. He worked on computational models of human vision that can be used to predict human visual abilities that are testable by psychophysical and electrophysiological methods. Professor of neurobiology was added to his title in 1989.

For his contributions to a variety of scientific areas, Glaser has received many honors. He was awarded the Henry Russell Award from the University of Michigan (1953), the Charles Vernon Boys Prize of the London Physical Society (1958), and the American Physical Society Prize (1959). For his invention of the bubble chamber, Glaser was awarded the Nobel Prize in Physics in 1960.

Significance

For atomic physicists, Glaser’s bubble chamber became second in importance to only the cyclotron for detecting high-energy elementary particles and studying high-energy nuclear physics. Notable discoveries made by using a bubble chamber include the discovery of weak neutral currents, which confirmed the validity of the electroweak theory and paved the way for the discovery in 1983 of the W and Z bosons that mediate the weak nuclear force. Bubble chambers have also been used in researching weakly interacting massive particles as a possible solution to the dark matter problem.

Bibliography

Allison, Amy. Luis Alvarez and the Development of the Bubble Chamber. Newark, Del.: Mitchell Lane, 2002. An overview of Glaser’s invention of the bubble chamber. Details of his subsequent work with Alvarez at UCB in the development of the hydrogen bubble chamber are presented in a clear, concise manner.

Bettini, Alessandro. Introduction to Elementary Particle Physics. Cambridge, England: Cambridge University Press, 2008. This book presents a clear, insightful description of the standard model of elementary particle physics, which includes contributions made to this field through implementation of Glaser’s bubble chamber. The interplay between theoretical and experimental physicists in developing an understanding of the fundamental forces of nature is discussed. Some photographs of data obtained using the bubble chamber are shown.

Galison, Peter Louis. Image and Logic: A Material Culture of Microphysics. Chicago: University of Chicago Press, 1997. Galison probes the use of simple to complex apparatuses in experimental microphysics, and what it means to be a physicist and do experimental physics. The development of experimental tools, such as Glaser’s bubble chamber, is explored. Coordination among instrument makers, theoretical physicists, and experimental physicists is examined.