Adrian Cho The Long Road to LIGO Science 353, 534-535, August 5, 2016
Physics: Will Nobel Prize overlook LIGO’s master builder? Barry Barish assembled the gravitational wave detectors but hasn’t shared the glory.
Adrian Cho
Next week, the 20th Nobel Prize in Physics will be announced, and many scientists expect it to honor the detection of ripples in space called gravitational waves, reported in February. If other prizes are a guide, the Nobel will go to the troika of physicists who 32 years ago conceived of LIGO, the duo of giant detectors responsible for the discovery: Ranier Weiss of the Massachusetts Institute of Technology (MIT) in Cambridge, and Ronald Drever and Kip Thorne of the California Institute of Technology (Caltech) in Pasadena. But some influential physicists, including previous Nobel laureates, say the prize, which can be split three ways at most, should include someone else: Barry Barish.
Barish, a particle physicist at Caltech, didn’t invent LIGO, the laser interferometer Gravitational-Wave Observatory. But he made it happen. The hardware at LIGO’s two observatories in Hartford, Washington, and Livingston, Louisiana; the structure of the collaboration; even the big-science character of gravitational research—all were molded by Barish, who is now 80. “Without him there would have been no discovery,” says Sheldon Glashow, a Nobel prize-winning theorist at Boston University, who has written to some members of the Nobel Committee arguing the case for Barish. “It would be an enormous injustice” if he didn’t share in the Nobel, Glashow says.
When Barish took over as the second director of the LIGO in 1994, he inherited a project that was “dead in the water,” says Richard Issacson, the National Science Foundation (NSF’s) program director for gravitational physics from 1973 to 2002. LIGO had hatched a decade earlier, when NSF began funding Weiss and Drever to marry their work on using interferometers—the L-shaped assemblages of lasers and mirrors—to detect the stretching of space set off by, say, two massive black holes spiraling together. But with Weiss, Drever and Thorne tripping over one another, the project remained larval. By 1987, NSF wanted a single director for the project, and Caltech appointed Rochus “Robbie” Vogt.
Decisive but volitile, Vogt pulled the team together to write a coherent proposal for twin interferometers with 4-kilometer-long arms. He won crucial support in Washington, D.C., says
Stanley Whitcomb, a LIGO physicist at Caltech. “Robbie was very effective in conveying to members of Congress the excitement of LIGO’s science,” he says. In 1980 the members of the National Science Board (NSB), which sets policy for the NSF approved construction of the observatory, priced at $250 million, the biggest thing that NSF had ever attempted.
But Vogt disdained bureaucratic oversight and vexed NSF officials. He kept the LIGO team unworkably small and refused to supply a detailed work plan or document researchers’ progress, Isaacson says. Things got so bad that in 1993 NSF asked Congress to hold back $43 million that the agency had requested for LIGO the following year. By the end of the year, Caltech eased Vogt out of leadership.
Barish brought swift and sweeping changes. Lank, soft-spoken, and even-tempered, he was born in Omaha, Nebraska, and raised in Los Angeles, California, where he attended public schools. He already had experience with big collaboration, having worked in a group of 140 physicists searching for particles called magnetic monopoles at Italy’s underground Gran Sasso National Laboratory. He had also worked on the biggest of big-science projects, the $10 billion Superconducting Super Collider in Waxahachie, Texas, which Congress canceled mid-construction in 1993.
First off, Barish reorganized LIGO management, expanding the team and delegating authority. Within months, he developed the detailed work plan that NSF wanted. Whereas Vogt stressed unfettered innovation, Barish likened LIGO to building a bridge —one that would be very long, complicated and expensive. He revised the project to improve infrastructure, such as the vacuum chambers that hold the interferometers. He also established permanent scientific staff at the two LIGO outposts and a steady R&D program for future upgrades. These changes required a budget boost to $292 million, Isaacson says, which NSB approved.
Barish and his deputy, Caltech’s Gary Sanders, also shook up the culture of the collaboration. Caltech physicists had a prototype interferometer and relied on experienced individuals to restart it daily. Barish and Sanders prodded them to run it steadily 24 hours a day and to study it methodically, eliminating what Sanders calls the “guru mentality.” The factorylike approach galled many of LIGO’s leading lights, who felt devalued and quit.
Meanwhile, Barish expanded LIGO beyond the bounds of Caltech and MIT. In 1997, he brought in new expertise by establishing the independent LIGO Scientific Collaboration (LSC), the group of external scientists who would use LIGO. “I don’t think we would have made the discovery in the time we did without that massive accumulation of intellect,” says David Berley, NSF’s project manager for LIGO from 1992 to 2000. Sanders says the decision to create LSC was initially unpopular among physicists who feared that big science was taking over their field. (It was.)
Key technical aspects of the LIGO interferometers reflect Barish’s touch, too. He decided to change the lasers that pump light into the instruments from ones that squeeze light from argon gas to more powerful and reliable solid-state lasers, then just coming to market. He also pushed to switch from analog to digital controls.
Construction of LIGO finished in 1999, and it began taking data 3 years later. Barish stepped down in 2005 to head up design of the International Linear Collider, a proposed 30-kilometer, straight-shot accelerator that some particle physicists say is the future of their field. But before giving up the reins, he ushered through plans for a crucial upgrade to the interferometers that ensured LIGO’s almost immediate success in detecting gravitational waves when the machine turned on a year ago. LIGO collaborators say Barish set a high standard for fairness and integrity. “I always felt appreciated and respeced by him,” says Gabriela Gonzalez of Louisiana State University, Baton Rouge, spokesperson for the 1100-member LSC.
Ironically, Barish recently tarnished his own sterling reputation. In May, at a meeting in Pittsburgh, Pennsylvania, he began an after-dinner talk with a slide showing a man writing on a woman’s bare back and next to her, a stage prop in the form of a cartoonish racial caricature. The incident ignited a Twitterstorm, and in a statement LSC disavowed the image as “inherently very offensive.” Barish says he found the photograph, from an early 20th century Broadway playbill, on the internet and was trying to make a play on the term “back story.” He says he hadn’t noticed the sexist and racist content. “I made a mistake, I should have been more careful,” he says.
Barish apologized to the entire LIGO collaboration by email. But Elizabeth Simmons, a theorist from Michigan State University in East Lansing, says she questioned Barish about the image at the dinner and that he dismissed her objection, saying “This [slide] is not my talk.” Tova Holmes, a graduate student at the University of California, Berkeley, who also attended the dinner, says, “Anybody who had ever thought about what it is like not to be a white man in physics would never have chosen that image.”
Other prizes suggest Barish is long-shot for the Nobel. Several awards have already honored LIGO’s discovery, including the Gruber Cosmology Price, the Kavli Prize in Astrophysics, the Shaw Prize in Astronomy, and the Special Breakthrough Prize in Fundamental Physics. All lauded Weiss, Drever, and Thorne, but not Barish.
The situation highlights a problem for prizes: They favor ideas over execution. “There isn’t a way to recognize good managment,” Gonzalez says. Whitcomb says that the U.S. National Medal of Science, honoring science in service to the nation, would be “well, well deserved” for Barish.
Of the Nobel, Barish says, “I think there’s a bit of truth that LIGO wouldn’t be here if I didn’t do it, so I don’t think I’m undeserving.” He’s hoping that the Nobel Committee takes the time to learn LIGO’s history. “If they wait a year and give it to these three guys, at least I’ll feel that they thought about it,” he says. “If they decide [to give it to them] this October, I’ll have more bad feelings because they won’t have done their homework.”
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