Tom Tombrello dies at 78; longtime Caltech physics professor

Caltech physics professor Tom Tombrello, right, speaks with a student in his Physics 11 class in 1994. Tombrello taught at the school for more than 50 years.
(Los Angeles Times)

Tom Tombrello, a Caltech physics professor for more than 50 years and an inspiration for freshmen who had to grapple with diabolically complex riddles to enter his legendary class on scientific thinking, has died. He was 78.

Tombrello collapsed Tuesday on a bus between terminals at London’s Heathrow airport, his wife, Stephanie, said. The cause of his death has not yet been determined.

As a researcher, Tombrello was known for his work in low-energy nuclear physics, but he delved into many other fields. One of his latest passions involved the biogenetics of cancer — an area of special interest following the 2008 death from pancreatic cancer of his daughter Kerstin Arusha.

Still an active faculty member, Tombrello was chair of Caltech’s Division of Physics, Mathematics and Astronomy from 1998 to 2008.


“He wasn’t just the DNA, but the heart and soul of Caltech,” said Sandra Tsing Loh, a 1983 graduate who went on to become a Los Angeles writer as well as the host of a radio feature called “Loh Down on Science.”

In 2005, Loh became the first alumna to give a Caltech commencement speech — an especially unusual achievement, given that her degree was, as she told the graduates, “entirely made of partial credit … glued together, faintly pulsing with radioactivity, graded less on a curve than on a kind of wild hyperbola asymptotically approaching some imaginary answer.”

Tombrello, who nurtured students both inside and outside the box, had been a big booster of Loh in her undergrad years. “Otherwise,” she said, “I would just be yet another defeated, unconfident student who grabbed their shaky diploma and ran from the place!”

Steven E. Koonin, Caltech’s former provost and currently head of New York University’s Center for Urban Science and Progress, was one of Tombrello’s undergraduate students in the early 1970s.


“Probably his greatest contribution to Caltech was the identification and mentoring of generations of promising undergraduate physicists,” said Koonin, who later became chief scientist for BP and a science official with the U.S. Department of Energy. “I was among the first of those. The process later became formalized through the Physics 11 course, which neatly embodied Tom’s enthusiasm and delight for helping younger scientists.”

Tombrello accepted only a handful of students for each year’s session of Physics 11.

Applicants had to address two screening questions — Tombrello called them “sort of a caricature of science” — and express their answers mathematically. A 1993 problem, slightly altering the old song “Mairzy Doats,” was typical: “Mares eat oats and does eat oaks and little lambs eat ivy.” Assume a small, equal number of each type of animal and type of vegetation, and assume that all are competing for space, Tombrello instructed. Now describe the evolution of the ecosystem.

Another problem: An interstellar expedition runs out of food and its members must turn to each other. How do the voyagers decide whom to eat first and still maintain an optimum population at journey’s end?


In a 2010 oral history, Tombrello said he turned down an attractive 1972 job offer from the University of Texas after he and a Caltech freshman had an hour-long conversation about a tough problem in accelerator design.

“It strikes me during this conversation that if I go to the University of Texas, I’m never going to have a conversation like this with an undergrad. I may never have a conversation like this with a grad student, not even with my colleagues. How can I possibly leave this place?”

Thomas Anthony Tombrello Jr. was born Sept. 20, 1936, in Austin, Texas. He received his bachelor’s, master’s and doctoral degrees in physics from Rice University in Houston.

Starting in 1961, he spent his career at Caltech, except for a 1963-64 stint as an assistant professor at Yale and leaves that included running a lab for the oil technology company Schlumberger.


Tombrello was an early champion of the planned, intensely powerful Thirty-Meter Telescope, formerly known as the California Extremely Large Telescope. He also explored earthquake prediction, focusing for a time on the possibility that increased levels of radon in the soil could foretell imminent quakes. Among other recent professional activities, he consulted on a musical about the inventor Nikola Tesla.

In addition to Stephanie Merton Tombrello, his wife of 37 years, Tombrello’s survivors include son Christopher Tombrello, daughters Susan Tombrello and Karen Burgess, and seven grandchildren. An earlier marriage ended in divorce.

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