New instrument extends LIGO’s reach
Just a year ago, the National Science Foundation-funded Laser Interferometer Gravitational-wave Observatory, or LIGO, was picking up whispers of gravitational waves every month or so. Now, a new addition to the system is enabling the instruments to detect these ripples in space-time nearly every week. Since the start of LIGO’s third operating run in April, a new instrument known as a quantum vacuum squeezer has helped scientists pick out dozens of gravitational wave signals, including one that appears to have been generated by a binary neutron star — the explosive merging of two neutron stars. The squeezer, as scientists call it, was designed, built, and integrated with LIGO’s detectors by MIT researchers, along with collaborators from Caltech and the Australian National University, who detail its workings in a paper published today in the journal Physical Review Letters. What the instrument “squeezes” is quantum noise — infinitesimally small fluctuations in the vacuum of space...