Sunday, February 25, 2018

Richard Taylor, Nobel-winning physicist who helped discover quarks, dies at 88



Richard Taylor, who won the Nobel Prize in physics for his experiments that demonstrated the existence of quarks, constituents of matter even more fundamental than the protons and neutrons that are commonly regarded as composing the atomic nucleus, died Feb. 22 at his home in California. He was 88.

Dr. Taylor lived on the campus of Stanford University, where he carried out the high-energy experiments that brought him his share of the 1990 Nobel. The university announced his death. No cause of death could be learned.

By demonstrating through experiment the reality of quarks, Dr. Taylor helped lay the foundation of what scientists know as the Standard Model of particle physics. The model, with quarks at its heart, establishes the fundamental particles of the universe and the forces that govern their interactions.

In Dr. Taylor’s experiments, electrons, possessed of enormous energies imparted by a linear particle accelerator, were smashed into protons. By studying the angles and directions in which the electrons flew away from the protons, scientists were able to recognize what lay within the protons.

In one notable description, the experiments demonstrated that the proton was not some ball of nuclear jelly, homogeneous and without structure. Rather, in the words of former Stanford accelerator director Persis Drell, it was more like jam with seeds embedded. The seeds were the quarks.
Richard Taylor, shown above in 1990, helped lay the foundation of what scientists know as the Standard Model of particle physics. (Chuck Painter/Stanford University)

To a significant degree, the work of Dr. Taylor and other scientists represented a milestone on the long path to find out what is at the heart of all the objects, large and small, that can be seen around us.

Democritus, in ancient Greece, put forward the idea that at its smallest level, the universe was made of atoms. At one time, the entire atom was thought to be tiny, solid and homogeneous.

Groundbreaking experiments early in the 20th century discovered that the atom was largely empty space, with a tiny but solid nucleus at its core. The nucleus, in turn, was found to be composed of protons and neutrons.

It was Dr. Taylor and his two co-winners of the Nobel Prize, Jerome I. Friedman and Henry W. Kendall, both then at the Massachusetts Institute of Technology, who showed by experiment from 1967 to 1973 that even the protons and neutrons were not nature’s fundamental building blocks.

“Before that time, we had this vast collection of particles and did not know how they were put together,” said Martin Breidenbach, a professor at the Stanford Linear Accelerator Center National 
Accelerator Laboratory who participated in the work while at MIT.

Richard Edwin Taylor was born Nov. 2, 1929, in the town of Medicine Hat in the province of Alberta in western Canada. He eventually held dual citizenship in the United States and in Canada.

As a boy, he read “quite a bit” and was good in mathematics but was otherwise “not an outstanding student,” he wrote in his Nobel biography. An early interest in chemistry, he once said, was discouraged when an experiment with explosives in his basement laboratory blew off parts of three fingers.

After receiving undergraduate and master’s degrees at the University of Alberta, he entered Stanford to work for his PhD. Interrupting his studies, he spent the period from 1958 to 1961 at a linear accelerator laboratory in Paris. On his return to the United States, he completed his dissertation and received his doctorate from Stanford in 1962.
It was about then that construction of the Stanford Linear Accelerator Center was starting up. He began working there, and his principal contributions to the research that would win the Nobel were in designing the experiments and in collecting and analyzing the data, according to Les Cottrell, who worked with Dr. Taylor in 1967.

An enormous amount of teamwork is involved in large-scale scientific experiments. The Stanford Linear Accelerator was one of the world’s largest atom smashers. Its size and the energies it could impart offered one of the best chances available not only to see the basic building blocks of the universe, but also to see inside them.

Enthusiasm was infectious, and traditional labor hierarchies dissolved. “I lived in mortal fear that a union steward would drop in unannounced,” Dr. Taylor once wrote, “and find a millwright [steelworker] building a wooden scaffold, while a carpenter was operating the crane.”

As the head of a group of scientists and engineers, Dr. Taylor gave an example of hands-on leadership. “He was an integral part of the experiment, not just the boss,” Cottrell said. “He would show up at 5 in the morning to take his shift, and he would be there in the evening” when the lab director came around to check on progress.

Scientists studied what was within protons by scrutinizing the paths electrons followed when they were bounced off the protons. As the experiment developed, Cottrell said, “there were too many particles coming off at a large angle than expected.” It was puzzling. Perhaps the measurements were off, some thought.

But finally theory and experiment merged. The unexpected angles meant unexpected objects within the proton. These objects, scientists came to recognize, were the quarks that had been predicted by theorist Murray Gell-Mann. He took the name from a sentence in James Joyce’s “Finnegans Wake”: “Three quarks for Muster Mark!”

Dr. Taylor’s experiments made him something of a celebrity, and his work became the subject of a clue on the television game show “Jeopardy!”

Survivors include his wife, the former Rita Bonneau, and a son.

While so much of Dr. Taylor’s work involved the design and construction of massive pieces of equipment with the sensitivity needed for the most delicate and refined measurements, Dr. Taylor recognized their larger meaning to science and to humanity.

“The quarks and the stars were here when you came,” he once said, “and they will be here when you go.”



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