The Future of Gravitational Wave Astronomy: Pulsar Webs, Space Interferometers and Everything

A merging of two massive objects, sending ripples through the fabric of space and time.  Image credit: R. Hurt/Caltech JPL

It’s the hot new field in modern astronomy. The recent announcement of the direct detection of gravitational waves by the Laser Interferometer Gravitational-wave Observatory (LIGO) ushers in a new era of observational astronomy that is completely off the electromagnetic spectrum. This detection occurred on September 15th, 2015 and later earned itself the name GW150914. This occurred shortly after Advanced LIGO turned on in early September, a great sign concerning the veracity of the equipment.Expect more to come. Perhaps the second gravitational wave detection won’t be as ground breaking as the first, but it is certainly a strange universe out there. LIGO didn’t happen overnight. The original LIGO ran for about a decade starting in 2002, with nary a gravitational chirp heard that managed to pass scientific scrutiny. There were actually Vegas odds placed on the direct detection of gravitational waves (along with CERN’s discovery of the Higgs-boson particle) way back in 2013: we hope no one lost their shirt on that one.And yes, you could trace the tale all the way back to Einstein’s general theory of relativity a century ago in 1916, positing the existence of gravitational ripples in the fabric of space-time. Early attempts to detect gravitational waves using giant cylindrical Weber bars in the 1960s and 70s highlighted just how difficult the hunt for the little buggers would ultimately prove to be. The type of motion LIGO is looking for is tiny, on the order of a 1/1000th the diameter of a proton. Everything in LIGO’s local environment shakes it more than that, the prime reason two geographically separate detectors are needed. The indirect detection of gravitational waves seen in the timing glitches of binary pulsar PSR B1913+16 earned Russell Hulse and Joseph Taylor the Nobel Prize in Physics —> Read More