Sunday, July 21, 2013

Donald Glaser, "Bubble Chamber" Inventor

Donald Glaser, Nobel Winner in Physics, Dies at 86



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Donald A. Glaser, who won the Nobel Prize in Physics in 1960 for inventing, at 25, an ingenious device called the bubble chamber to trace the paths of subatomic particles, died on Thursday at his home in Berkeley, Calif. He was 86.

Associated Press
Donald A. Glaser in 1960 with the bubble chamber invention that won him the Nobel Prize in Physics.
His death was confirmed by his wife, Lynn.
In creating the chamber, Dr. Glaser — a restless scientist who later turned to microbiology and developing cancer therapies — proved his most renowned skeptic, Enrico Fermi, a giant of 20th-century physics, wrong.
In the 1950s, physicists were becoming more adept at building powerful atom smashers to help decipher the building blocks of matter. But in breaking atoms apart they were often stymied in their efforts to identify the particles that flew out from the collisions.
Dr. Glaser’s bubble chamber generated data that enabled physicists to figure out that most particles of matter, like protons and neutrons, are composed of even smaller particles known as quarks.
“It was a very powerful technique,” said Nicholas Samios, a physicist at Brookhaven National Laboratory on Long Island. “It was very instrumental in that period of physics.”
Dr. Glaser, who was teaching at the University of Michigan at the time, was fortunate that he did not know that Fermi had calculated that a bubble chamber would never work. Only afterward, after Fermi had invited Dr. Glaser to the University of Chicago to give a talk about the bubble chamber, did Dr. Glaser look up Fermi’s calculation in a thermodynamics textbook. There he found an erroneous equation.
“It’s just a small error, but that error made it possible for him to prove that it couldn’t work,” Dr. Glaser said of the bubble chamber in an oral history conducted by the Bancroft Library at Berkeley. “And luckily I didn’t know about his book because it would have turned me off. Instead, I did my own calculation, and it was hard, but that was the critical difference.”
After winning the Nobel, Dr. Glaser, frustrated that particle physics was adopting huge atom smashers requiring large teams of scientists, switched to molecular biology and studied bacteria and viruses.
In 1971, with two others, he helped found one of the first biotechnology companies, the Cetus Corporation, which developed the cancer therapies interleukin-2 and interferon. The company was sold in 1991 to Chiron Corporation, which is now part of Novartis.
In the 1980s, Dr. Glaser switched fields again, this time to study the neurobiology of vision. He began conducting experiments to understand how humans perceive motion and then developed mathematical models that mimicked that process.
“A little bit naïve in the very right way,” Tomaso Poggio, a professor of brain and cognitive sciences at the Massachusetts Institute of Technology, said of Dr. Glaser. “Naïve enough to be really original.”
Donald Arthur Glaser was born on Sept. 21, 1926, in Cleveland, to William J. Glaser, a businessman, and his wife, Lena. After attending public schools, he received a bachelor’s degree in physics and mathematics in 1946 from the Case School of Applied Science, which later became part of Case Western Reserve University. He earned a doctorate from the California Institute of Technology. He joined the faculty at Michigan in 1949 and invented the bubble chamber in 1952, before his 26th birthday.
In the early ’50s, a gas-filled cloud chamber was the primary device for observing debris from atom smashers. As particles passed through the gas, which was on the verge of condensing, they left behind a trail of tiny droplets, which could be photographed.
But cloud chambers had limitations. “They’re harder to operate, and it wasn’t as easy to make them bigger,” Dr. Samios said.
Dr. Glaser replaced the gas with an unstable liquid. When a particle passed through, it left behind a trail of bubbles, which were then photographed. Because a liquid is denser than a gas, a bubble chamber could show a particle’s trajectory in greater detail than a cloud chamber could. “Fantastically better,” Dr. Samios said.
The first bubble chamber was just an inch wide, but physicists built larger and larger ones through the 1960s into the 1970s before other technologies superseded them.
In 1964, for example, Dr. Samios led a team that used an 80-inch bubble chamber at Brookhaven to discover a particle called the omega-minus, which helped confirm the quark theory.
Dr. Glaser moved from Michigan to the University of California, Berkeley, in 1959. He was 34 when he won the Nobel, in 1960.
Dr. Glaser’s first marriage, to Ruth Bonnie Thompson, ended in divorce. In addition to his wife, the former Lynn Bercovitz, he is survived by a daughter, Louise, and a son, William, both from his first marriage, and four grandchildren.
Dr. Glaser always denied popular accounts suggesting that he had been inspired to create the bubble chamber by staring at a glass of beer. “It’s totally wrong,” Dr. Glaser said in the oral history interview. “The story is perverted by journalists.”
But he did attempt to use beer in a bubble chamber as he looked for an alternative to the first liquid he used, an organic compound known as diethyl ether.
“Why fool around with all of these exotics?” Dr. Glaser recalled. “Water is probably out of the question, but I decided, ‘What the hell?’ ”
It didn’t work, but in heating the beer, it sprayed the ceiling, and the physics building stank of beer. That, he said, was a problem for two reasons. First, alcohol was not allowed within 500 yards of the campus.
“The other problem was that the chairman was a very devout teetotaler, and he was furious,” Dr. Glaser said. “He almost fired me on the spot.”

This article has been revised to reflect the following correction:
Correction: March 5, 2013
An earlier version of this obituary misidentified an organic compound that was the first liquid Dr. Glaser used in the bubble chamber. It was diethyl ether, not diethyl ester. Because of an editing error, the obituary also referred incorrectly to the college from which Dr. Glaser received his bachelor’s degree. It was the Case School of Applied Science, which later became part of Case Western Reserve University; it was not “what became the Case Western University.”

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