Delbrück Centennial

A day of science, remembrances, and partying marked the 100th anniversary of the birth of Nobel laureate, molecular biology pioneer, and Caltech professor Max Delbrück. The party, at the Delbrück home one block east of campus, was in keeping with the biologist’s penchant for high-spirited shenanigans—until his retirement in 1977, he was known as quite the campus prankster.

“That home became a second home to many of us,” recalled Seymour Benzer, the Boswell Professor of Neuroscience, Emeritus, who showed footage of a hike to the bottom of the Grand Canyon in 1949, hosted by Delbrück and his wife Manny. “I had never climbed more than two staircases in my life,” Benzer joked. “After 18 miles, I became a unit of tiredness.”

Former postdoc Gunther Stent, who went on to establish both the department of virology and the department of molecular biology at UC Berkeley, from where he retired in 1992, recounted Delbrück’s early scientific career. Delbrück trained as a theoretical physicist in Göttingen, Germany, but the discipline never fully captured his interest. Just before he came to Caltech in 1937 for a yearlong Rockefeller Fellowship, he was inspired by physicist Niels Bohr to explore the relation of atomic physics and biology, and thus began his foray into the biological realm. Delbrück commenced genetic work on Drosophila, a genus of fruit fly that was already becoming a workhorse of molecular genetics, but the forbidding-looking papers categorizing every one of the fly’s genotypes turned him off. By the time he returned to the Institute as a biology professor in 1947, he was fascinated by the question of how viruses infect bacteria, and founded the freewheeling “phage lab,” which essentially pioneered the field of bacterial genetics. This work led to a Nobel Prize in Physiology or Medicine in 1969, but according to Stent, accepting it was difficult for Delbrück. He felt the prize contradicted the “Copenhagen Spirit”—an ideal that stressed self-criticism and an egalitarian regard for scientific findings.

Remembrances of Delbrück’s early years gave way to today’s frontiers of biophysical research. After jokingly referring to himself as an “extinguished” fellow of the Salk Institute, molecular biologist and Nobel laureate Sydney Brenner, an occasional visitor to Caltech since 1960, challenged the audience to tackle biological complexity by returning to phage biology. “The best thing we can do in biology is what we’re damned good at: the forward problem. We can’t do the inverse problem—I call that the ‘low-input, high-throughput, no-output problem,’” he said. Howard Berg (BS ’56), now a professor of both physics and molecular and cellular biology at Harvard University, recalled how Delbrück’s influence led him to study E. coli. Delbrück once told Berg that if he had to do it over again he’d work with bacteria, but he didn’t know how to tame them. The word “tame” caught Berg’s interest, and the rest, as they say, is history. Berg gave a nod to the Caltech team that took 3-D pictures of a bacterium’s flagellar motor (see E&S, 2006, No. 3, p. 6); he himself studies the rotary motor of E. coli’s flagella. Max Delbrück’s son Tobi Delbrück (PhD ’93) came from Zurich, where he teaches neuroinformatics at the Eidgenössische Technische Hochschule (ETH), and showed off his new toy—a retina built like the human eye’s, but in the form of a silicon chip. He had been inspired to his current pursuits during his graduate work with the senior Delbrück’s colleague Carver Mead (BS ’56, MS ’57, PhD ’60), the Moore Professor of Engineering and Applied Science, Emeritus.

The celebration resonated even for those who had never met the legend. Rob Phillips, professor of applied physics and mechanical engineering, credited Delbrück for influencing his own career path, which has led to insights into how DNA is packed into viruses—like balls filling a bathtub and locking together to form hexagons. “He’s an abstraction, a myth, and a legacy in the same way Feynman or Gibbs might be,” Phillips said.

The centennial ended as one imagines it would have in Delbrück’s day, with movies and jokes. Professor emeritus and former chair of the biology division Ray Owen recalled the party that marked his last day of chairmanship in 1968. Delbrück presented to Owen an accurate metal sundial fabricated in the astrophysics shop, and then began scribbling on the board a lengthy equation of time demonstrating how it worked.

Finally, under Benzer’s direction, the audience joined in with recordings of Delbrück himself, singing a parody by former biology student Sandra Winicur (PhD ’71) of The First Lord’s Song from Gilbert and Sullivan’s HMS Pinafore. Imagining a Nobel laureate belting out this first verse might amuse many a Caltech grad:

When I was a youth, I wanted to be
A full Professor in Biology.
How I could become one was hard to see
Since my IQ was only ninety-three. —EN