Ligo Project Site, Washington

LIGO (the Laser Interferometer Gravitational-wave Observatory) is a research facility on the grounds of the Hanford Reservation, built to record otherwise undetectable gravitational waves striking the earth. The facility consists of a control building, from which a pair of two mile long, ground-level tubes extend at a right angle from one another. A laser is projected through the near-perfect vacuum maintained within these long chambers, bouncing back to detectors in the control building. The facility acts like a giant optical microphone, tuned to gravity waves generated by distant celestial entities. It is a collaboration between Caltech and MIT, funded by the National Science Foundation, and is coupled with an identical facility in Louisiana.