An Advanced Look

Caltech president Thomas Rosenbaum inspects a vacuum chamber at the Laser Interferometer Gravitational-wave Observatory (LIGO) in Hanford, Washington, during a tour lead by observatory head Frederick Raab (right) at the May 19 Advanced LIGO dedication. Inside the chamber, in an ultra-high vacuum environment, several pristine mirrors hang in carefully balanced suspension, directing laser light into the gravitational-wave detector’s 4-kilometer beam paths. LIGO was designed and is operated by Caltech and MIT, with funding from the National Science Foundation (NSF). Advanced LIGO, also funded by the NSF, is expected to begin its first searches for gravitational waves this fall, possibly as you are reading these pages. The Advanced LIGO Project is a major upgrade that should increase the sensitivity of the detector by a factor of 10 and provide a 1,000-fold increase in the number of astrophysical candidates for gravitational-wave signals. “Advanced LIGO represents a critically important step forward in our continuing effort to understand the extraordinary mysteries of our universe,” said NSF director France Córdova (PhD ’79) at the dedication. “It gives scientists a highly sophisticated instrument for detecting gravitational waves, which we believe carry with them information about their dynamic origins and about the nature of gravity that cannot be obtained by conventional astronomical tools."