03/09/2009 07:00:00

New Gift Allows Caltech and Cornell Scientists to Continue Simulating Warped Space-time

PASADENA, Calif.—The Sherman Fairchild Foundation has awarded $3.1 million to the California Institute of Technology (Caltech) to support the Caltech-Cornell Program for Simulation of eXtreme Spacetimes (SXS) through 2013. Earlier funding from the foundation, along with federal grants, built the renowned, eight-year-old SXS program, in which then-postdoctoral student Frans Pretorius achieved the first complete simulation of the collision and merger of two black holes by solving Einstein’s relativity equations on supercomputers (“numerical relativity”).

Under the auspices of Caltech’s Kip Thorne, the Richard P. Feynman Professor of Theoretical Physics, and the hands-on leadership of Drs. Lee Lindblom and Mark Scheel at Caltech and Professor Saul Teukolsky and Dr. Larry Kidder at Cornell, the SXS team is perfecting a computer code that employs a highly accurate, but challenging mathematical technique called the “spectral method.”  With their Spectral Einstein Code (SpEC), as they call it, the SXS team is simulating neutron stars being ripped apart by black holes, and the collisions of black holes. These cataclysmic events create wild oscillations in the fabric of space and time, and send gravitational waves rippling through the universe, phenomena that the team simulates with exquisite detail.

These simulations are the theory side of a theoretical and observational collaboration aimed at revealing the roles of highly warped spacetime in our universe.  The observational side includes the gravitational waves.  They will be observed by the Caltech-led Laser Interferometer Gravitational-Wave Observatory (LIGO) and by a future gravitational-wave detector in space, called LISA.  When searching for waves in LIGO’s or LISA’s noisy data, gravitational astronomers need to know what wave shapes to look for--and when interpreting observed waves, the scientists must know precisely what wave shapes are produced by each of a myriad of possible wave sources.  Computer simulations provide the answers.

In their black-hole simulations, the SXS team has already achieved the high accuracies that will ultimately be needed by LIGO scientists (3/1000 of a wave cycle out of hundreds or thousands of cycles), but only for holes that are not spinning, or have spins in special directions.  By contrast, other physicists in Europe and the United States, using a more conventional technique called “finite differencing,” are able to simulate robustly a wider range of black holes, but with accuracies much worse than LIGO’s ultimate requirements.

The Fairchild Foundation’s gift, together with continuing federal funding, will pay supercomputing costs and the salaries for the SXS team’s talented young researchers as they make their SpEC code fully robust, carry out thousands of simulations in support of LIGO, and begin simulating other warped-spacetime phenomena, such as the cores of supernovae, the “singular” cores of black holes, and the collapse of wormholes.

“The Sherman Fairchild Foundation is a core supporter of science and scholarship and a great friend to Caltech," says Caltech president Jean-Lou Chameau. "The foundation’s investments in Caltech have advanced science and engineering in several fields. Its pivotal early support for the SXS research program changed the face of numerical relativity. With gravitational-wave detection and supercomputing capabilities accelerating, the foundation’s new gift is timed to once again spur dramatic breakthroughs in theoretical physics.”

Says Thorne, “With this grant, our talented team will simulate the phenomena that LIGO observes, and will gain insights, for the first time, into how warped space and warped time behave when thrown into wild motions like the ocean in a storm.  This has become my own personal research passion.”

Saul Teukolsky, the leader of the Cornell part of the SXS team, says, “Until recently, I was worried that the experimenters might detect gravitational waves from black holes and we theorists would not be able to say whether the observations agreed with the predictions of Einstein’s theory or not. But now I’m confident that we’ll be ready when the waves are detected.”

A supporter of Caltech for many years, the Sherman Fairchild Foundation has also endowed the Sherman Fairchild Postdoctoral Scholars Program and provided vital funding for the Cahill Center for Astronomy and Astrophysics, the Center for Computational Research in Biology, and the Sherman Fairchild Library of Engineering and Applied Science.


 About Caltech:
Caltech is recognized for its highly select student body of 900 undergraduates and 1,200 graduate students, and for its outstanding faculty. Since 1923, Caltech faculty and alumni have garnered 32 Nobel Prizes and five Crafoord Prizes.

In addition to its prestigious on-campus research programs, Caltech operates the W. M. Keck Observatory on Mauna Kea, the Palomar Observatory, the Laser Interferometer Gravitational-Wave Observatory (LIGO), and the Jet Propulsion Laboratory. Caltech is a private university in Pasadena, California. For more information, visit http://www.caltech.edu.

Written by Jon Weiner