Construction of Advanced LIGO reaches milestone early

BBC : The Laser Interferometer Gravitational-Wave Observatory (LIGO) attempted to detect gravitational waves by looking for variations in long beams of laser light. Gravitational waves are predicted to be caused by the rotation of binary neutron star or black hole systems as the extreme masses create ripples in spacetime. The original LIGO project, which ran from 2001 to 2010, saw no sign of gravitational waves. For the past four years, the facility has been undergoing upgrades to increase its sensitivity by a factor of 10. That will allow the observatory to look for gravitational waves that originate within 200 Mpc (600 million light-years) of Earth. The facility achieved “full lock"—it turned on and maintained operation for 10 minutes—in June, a year before originally scheduled to do so. While not yet fully upgraded, the observatory is already 30% more sensitive than it was on its original run. Because of the success with the upgrades, project leader Andreas Freise of the University of Birmingham in the UK expects the facility to begin observations next summer.