Leon Lederman, 96, Explorer (and Explainer) of the Subatomic World, Dies

Leon Lederman, whose ingenious experiments with particle accelerators deepened science’s understanding of the subatomic world, died early Wednesday in Rexburg, Idaho. He was 96.

His wife, Ellen Carr Lederman, confirmed the death, at a care facility. She and Lederman, who had long directed the Fermi National Accelerator Laboratory outside Chicago, had retired to eastern Idaho.

Early in his career Leon Lederman and two colleagues demonstrated that there are at least two kinds of particles called neutrinos (there are now known to be three), a discovery that was honored in 1988 with a Nobel Prize in physics. He went on to lead a team at the Fermi laboratory, in Batavia, Illinois, that found the bottom quark, another fundamental constituent of matter.

For those baffled by such esoterica, Lederman was quick to sympathize.

“'The Two Neutrinos’ sounds like an Italian dance team,” he remarked in his Nobel banquet speech. But he was determined to spread the word about the importance of the science he loved:

“How can we have our colleagues in chemistry, medicine, and especially in literature share with us, not the cleverness of our research, but the beauty of the intellectual edifice, of which our experiment is but one brick?”

He used his share of the prize winnings (physicists Jack Steinberger and Melvin Schwartz were also awarded the Nobel in 1988) to buy a log house in Idaho, in the Teton Valley, where he would later retire. By that time he was known as a pre-eminent figure in both discovering new physics and explaining it to the rest of the world.

“We’re teaching high school science in the wrong order — biology, chemistry and then, for 20 percent of the students, eventually physics,” he told Claudia Dreifus in an interview with The New York Times in 1998. That, he contended, was upside down.

“The subjects are unrelated, to be learned and forgotten — in the order taken,” Lederman lamented. Much better, he said, would be to begin with physics, including a basic understanding of atoms. That would lay the groundwork for chemistry, in which atoms join to form molecules, and then biology, where the interaction of molecules gives rise to life. Maybe next could come psychology.

A curriculum like that, called Physics First, would reprise the history of the universe, Lederman said: “Atoms formed molecules, and the molecules formed things that crawled out of the ocean. And here we are, worrying about the whole thing!”

Joseph D. Lykken, a theoretical physicist at Fermilab, said he considered Lederman “the best ambassador of physics to the general public since Einstein.”

“Instead of intimidating people with fancy jargon and mathematical equations, Leon had the ability to convey the genuine joy and fun of doing science,” Lykken said in an interview. “He used his inexhaustible grab bag of jokes to burst the bubble of the scientist as dignified brainiac and bring modern science back to the human scale.”

Reaching for ways to make physics go down easier, he nicknamed the Higgs boson “the God particle,” to the consternation of some colleagues. That was also the name of his book — a popularization of physics published in 1993 — written with science journalist Dick Teresi.

“The publisher wouldn’t let us call it the God-damn particle,” they wrote, noting how successfully the Higgs was eluding capture in particle accelerator experiments. Its existence was not established until 2012. (The Higgs boson, which interacts with other particles to give them mass, was named after the British theoretical physicist Peter Higgs.)

The source of his humor, Lederman said in the Times interview, came “from a terror of taking myself seriously.”

Leon Max Lederman was born on July 15, 1922, in Manhattan, where his parents, Morris and Minna (Rosenberg) Lederman, Jewish immigrants from Russia, ran a laundry business. Leon grew up in the Bronx and graduated from James Monroe High School in 1939 and from City College of New York in 1943. His bachelor’s degree was in chemistry, but by then he was already finding himself drawn to physics.

After serving in France during World War II with the Army Signal Corps, he entered the graduate school of physics at Columbia University, where he received his Ph.D. in 1951. He was soon working at the school’s new particle accelerator, just up the Hudson River at the Nevis Laboratories in Irvington, New York. It was there in 1957 that he performed his first eye-catching experiment. Two theorists, Tsung-Dao Lee and Chen-Ning Yang (who shared the Nobel Prize that year), had speculated, amid widespread skepticism, that the weak nuclear force, which is involved in radioactive decay, might violate a law of physics called conservation of parity.

This idea is sometimes explained metaphorically with the example of a mechanical clock. Built in its mirror image — with the gears turning counterclockwise instead of clockwise and the numerals on the face reversed — it would still indicate the proper time.

When it comes to left or right and clockwise or counterclockwise, the law of conservation of parity holds that the universe doesn’t care one way or the other. Physicists had widely assumed that this equivalence held true for all the forces of nature, whether at the scale of galaxies or on the subatomic realm.

During a regular Friday lunch at a Chinese restaurant near Columbia, Lee told Lederman and some other associates that physicist Chien-Shiung Wu had just completed an experiment that appeared to show that the weak force, unlike the others, indeed violated parity. During the decay of a nuclear isotope, gamma rays were more likely to be emitted in one direction than the other.

After heading upriver that evening to the Nevis Laboratories, Lederman and Richard Garwin, along with a graduate student, Marcel Weinrich, worked through the weekend and confirmed Wu’s discovery using a different experimental approach.

That clinched the deal, and the violation of parity caused a sensation. An exception had been found to a fundamental physical law. The universe was stranger than it seemed.

Lederman recalled the thrill of finding a new phenomenon in an interview in 1981 with Times science writer Malcolm W. Browne in Discover magazine. “The best discoveries always seem to be made in the small hours of the morning, when most people are asleep, where there are no disturbances and the mind becomes most contemplative,” he said.

“You’re out in a lonely spot somewhere, looking at the numbers on reams of paper spewing out of a computer,” he continued. “You look and look, and suddenly you see some numbers that aren’t like the rest — a spike in the data.

“You apply some statistical tests and look for errors, but no matter what you do, the spike’s still there. It’s real. You’ve found something. There’s just no feeling like it in the world.”

In 1962, his experiment at Brookhaven National Laboratory on Long Island with Schwartz and Steinberger demonstrated the existence of two kinds of neutrinos. One is associated with the electron and another with its heavier cousin, the muon. Later on, physicists found an even heftier version of the electron called the tau, which is accompanied by a tau-neutrino.

These discoveries ultimately helped form the scaffolding for the Standard Model, a crowning achievement of 20th-century physics. Everything is made from three families of subatomic particles, each of which also includes a pair of quarks.

It was one of these — the bottom quark — that Lederman and his Fermilab team discovered in 1977. (Quarks called up, down, strange and charm had already been confirmed by other scientists, and in 1995 the top quark was found, also at Fermilab.)

After leaving Columbia University, Lederman became director of Fermilab in 1979. There he oversaw the construction of the Tevatron, the most powerful accelerator of its day, capable of colliding particles at energies up to 1 trillion electron-volts. Probing deeper into the pieces of matter would require even more firepower, and throughout the 1980s Lederman was an avid promoter of government funding for the Superconducting Super Collider, which would have been the most powerful machine on the planet, to be built in Texas. The dream was dashed when Congress canceled funding in 1993.

By then Lederman had retired from Fermilab to become a professor of physics at the University of Chicago. He also continued to promote science education. In 1992 he served as president of the American Association for the Advancement of Science.

He and his wife, Ellen, moved to their place in Idaho, in Driggs, just before his 90th birthday. Found to have dementia, he was advised by his doctors to live in peaceful surroundings. In 2015 the couple agreed to let an online auction company sell his Nobel Prize medal. The proceeds, $765,002 before taxes, were set aside for future medical expenses.

By then he had forgotten his years as director of Fermilab, or what he had done to win the prize.

“I don’t have any real stories to tell about it,” he told The Associated Press in 2015. “I sit on my deck and look at the mountains.”

Lederman’s first wife, Florence Gordon Lederman, died in 1990. He married Ellen Carr in 1981. In addition to her, he is survived by three children from his first marriage: two daughters, Rena Lederman, a professor of anthropology at Princeton, and Rachel Lederman, a civil rights lawyer; and a son, Jess, a writer and the creator of a website devoted to the works of the Scottish novelist, poet and minister George MacDonald, as well as five grandchildren. “There’s always a place at the edge of our knowledge, where what’s beyond is unimaginable, and that edge, of course, moves,” Lederman told The Times in 1998.

In the beginning were the laws of physics. But where did the laws come from? At that point, he said, “You’re stuck.”

“I usually say, ‘Go across the street to the theology school, and ask those guys, because I don’t know.'”