Exquisite Sensitivity

LIGO interferometers around the world have been listening for weak signals from cosmic events for decades. So far they are more interesting for how they work than what they have found.

On September 18, 2015, Advanced LIGO became fully operational and began formal science operations at twice the sensitivity of the initial interferometers. wikipedia

"The one thing I personally like about Ligo is it's used every bit of physics I know, from the most arcane solid-state and surface physics to lasers, electronics, quantum mechanics - everything," said Vern Sandberg, the lead scientist at the Hanford lab. bbc

Within weeks after a 200 million dollar upgrade at Hanford, Washington, rumor has it that an event has been observed. Reports caution that this could be intentionally fictitious data injected to keep scientists and journalists from over reacting. nature

This has happened before. A rather strong signal was observed on September 16, 2010, within a minute or so of its apparent arrival at the detectors. The scientists on duty at the detector sites immediately recognized the tell-tale chirp signal expected from the merger of two black holes and/or neutron stars, and sprang into action. They knew that it could be a blind injection, but they also knew to act like it was the real thing. post

This quest to detect gravitational waves has consumed scientific lifetimes. Vern Sandberg could have also mentioned the socially innovative devices they have constructed. I feel some empathy having spent years to build a mechanism that could receive messages on another unexplored channel. See Unintended Product

See Commissioning Story for jargon filled quotes from a LIGO popular publication.

Gravitational-wave data show tentative signs of firewalls or other exotic physics. nature

Astrophysicists may have detected gravitational waves last week from the collision of two neutron stars in a distant galaxy — and telescopes trained on the same region might also have spotted the event. nature

PSR 1913+16 was the first binary pulsar to be discovered. It was discovered by Russell Alan Hulse and Joseph Hooton Taylor, Jr., of the University of Massachusetts Amherst in 1974. wikipedia

You can make all of the elements up to iron in massive stars, and the abundances found in the universe agree pretty well with the models of the life and death of these stars, but the heavier elements such as gold, lead, and uranium just didn’t compute. post

The rapid neutron capture process or r-process is a set of reactions in nuclear astrophysics that are responsible for the creation of approximately half the atomic nuclei heavier than iron. wikipedia