2017-10-03 07:40:02
2017 Nobel Prize in Physics Awarded to LIGO Black Hole Researchers

07:40, October 03 67 0

Rainer Weiss, a professor at the Massachusetts Institute of Technology, and Kip Thorne and Barry Barish, both of the California Institute of Technology, were awarded the Nobel Prize in Physics on Tuesday for the discovery of ripples in space-time known as gravitational waves, which were predicted by Albert Einstein a century ago but had never been directly seen.

In February 2016, when an international collaboration of physicists and astronomers announced that they had recorded gravitational waves emanating from the collision of a pair of massive black holes a billion light years away, it mesmerized the world. The work validated Einstein’s longstanding prediction that space-time can shake like a bowlful of jelly when massive objects swing their weight around, and it has put astronomers on intimate terms with the deepest levels of physical reality, of a void booming and rocking with invisible cataclysms.

Dr. Weiss, 85, Dr. Thorne, 77, and Dr. Barish, 81, were the architects and founders of that collaboration, known as LIGO, the Laser Interferometer Gravitational-wave Observatory, along with the late Ron Drever, also of Caltech, who died this year.

Dr. Barish, who directed the project from 1994 to 2005, reorganized what had been a brilliant and ambitious, but sputtering, project into a well-managed project of Big Science, laying the foundation for its eventual success.

Einstein’s General Theory of Relativity, pronounced in 1916, suggested that matter and energy would warp the geometry of space-time the way a heavy sleeper sags a mattress, producing the effect we call gravity. His equations described a universe in which space and time were dynamic. Space-time could stretch and expand, tear and collapse into black holes — objects so dense that not even light could escape them. The equations predicted, somewhat to his displeasure, that the universe was expanding from what we now call the Big Bang, and it also predicted that the motions of massive objects like black holes or other dense remnants of dead stars would ripple space-time with gravitational waves.

These waves would stretch and compress space in orthogonal directions as they went by, the same way that sound waves compress air. They had never been directly seen when Dr. Weiss and, independently, Dr. Drever, then at the University of Glasgow, following work by others, suggested detecting the waves by using lasers to monitor the distance between a pair of mirrors. In 1975, Dr. Weiss and Dr. Thorne, then a well-known gravitational theorist, stayed up all night in a hotel room brainstorming gravitational wave experiments during a meeting in Washington.

Dr. Thorne went home and hired Dr. Drever to help develop and build a laser-based gravitational-wave detector at Caltech. Meanwhile, Dr. Weiss was doing the same thing at M.I.T.

The technological odds were against both of them. The researchers calculated that a typical gravitational wave from out in space would change the distance between the mirrors by an almost imperceptible amount: one part in a billion trillion, less than the diameter of a proton. Dr. Weiss recalled that when he explained the experiment to his potential funders at the National Science Foundation, “everybody thought we were out of our minds.”

The foundation, which would wind up spending $1 billion over the next 40 years on the project, ordered the two groups to merge. The plan that emerged was to build a pair of L-shaped antennas, one in Hanford, Wash., and the other in Livingston, La., with laser light bouncing along 2.5-mile-long arms in the world’s biggest vacuum tunnels to monitor the shape of space.

In 1987, the original three-headed leadership of Drs. Weiss, Drever and Thorne was abandoned for a single director, Rochus Vogt of Caltech. But the project foundered until Dr. Barish, a Caltech professor with a superb pedigree in managing Big Science projects, was asked to step in as director in 1994. He reorganized the project so that it would be built in successively more sensitive phases, and he created a worldwide LIGO Scientific Collaboration of astronomers and physicists to study and analyze the data.

“Without him there would have been no discovery,” said Sheldon Glashow, a Nobel Prize-winning theorist now at Boston University.

The most advanced version of LIGO had just started up in September 2015 when the vibrations from a pair of colliding black holes slammed the detectors in Louisiana and Washington with a rising tone, or “chirp,” for a fifth of a second.

It was also the opening bell for a whole new brand of astronomy. Since then LIGO (recently in conjunction with a new European detector, Virgo) has detected at least four more black hole collisions, opening a window on a new, unsuspected class of black holes, and rumors persist of even more exciting events in the sky.

Dr. Weiss was born in Berlin in 1932 and came to New York by way of Czechoslovakia in 1939. As a high school student, he became an expert in building high-quality sound systems and entered M.I.T. intending to major in electrical engineering. He inadvertently dropped out when he went to Illinois to pursue a failing romance. After coming back, he went to work in a physics lab and wound up with a Ph.D. from M.I.T.

Dr. Thorne was born and raised in Utah, receiving a bachelor’s degree from Caltech and then a Ph.D. from Princeton under the tutelage of John Archibald Wheeler, an evangelist for Einstein’s theory who coined the term black holes, and who initiated Dr. Thorne into their mysteries. “He blew my mind,” Dr. Thorne later said. Dr. Thorne’s enthusiasm for black holes is not confined to the scientific journals. Now an emeritus professor at Caltech, he was one of the creators and executive producers of the 2014 movie “Interstellar,” about astronauts who go through a wormhole and encounter a giant black hole in a search for a new home for humanity.

Dr. Barish was born in Omaha, Neb., was raised in Los Angeles and studied physics at the University of California, Berkeley, getting a doctorate there before joining Caltech. One of the mandarins of Big Science, he had led a team that designed a $1 billion detector for the giant Superconducting Supercollider, which would have been the world’s biggest particle machine had it not been canceled by Congress in 1993, before being asked to take over LIGO.

Subsequently, Dr. Barish led the international effort to design the International Linear Collider, which could be the next big particle accelerator in the world, if it ever gets built.

The awarding of a Nobel to Drs. Weiss and Thorne completes a kind of scientific Grand Slam. In the last two years, along with Dr. Drever, they have shared a cavalcade of prestigious and lucrative prizes including the Kavli Prize for Astrophysics, the Gruber Cosmology Prize, the Shaw Prize in Astronomy and a Special Breakthrough Prize in Fundamental Physics. It is possible that had he lived, Dr. Drever would have shared in the Nobel as well, but he died last March, and the Nobel is not awarded posthumously.

Jeffrey C. Hall, Michael Rosbash and Michael W. Young were awarded the Nobel Prize in Medicine on Monday for discoveries about the molecular mechanisms controlling the body’s circadian rhythm.

David J. Thouless, F. Duncan M. Haldane and J. Michael Kosterlitz were recognized for research into the bizarre properties of matter in extreme states, including superconductors, superfluids and thin magnetic fields.

Four more will be awarded in the days to come:

■ The Nobel Prize in Chemistry will be announced on Wednesday in Sweden. Read about last year’s winners, Jean-Pierre Sauvage, J. Fraser Stoddart and Bernard L. Feringa.

■ The Nobel Prize in Literature will be announced on Thursday in Sweden. Read about last year’s winner, Bob Dylan.

■ The Nobel Peace Prize will be announced on Friday in Norway. Read about last year’s winner, President Juan Manuel Santos of Colombia.

■ The Nobel Memorial Prize in Economic Science will be announced on Monday, Oct. 9, in Sweden. Read about last year’s winners, Oliver Hart and Bengt Holmstrom.