LIVINGSTON — Tucked away in a pine forest north of Livingston, an enclave of scientists continues to push forward in its quest to find “ripples in space-time.”
The Laser Interferometer Gravitational-Wave Observatory, or LIGO, is undergoing a massive upgrade to cast a wider net as it scours the universe. The scientists at LIGO hope to be the first to observe a gravitational wave as it passes through Earth.
“It would be amazing. It would be first-page news in newspapers across the world. … This is a very exciting prediction,” said Gabriela Gonzalez, LSU professor of physics and astronomy and spokeswoman for the LIGO Scientific Collaboration.
Violent cosmic events such as the collision of stars and the vibrations of black holes send light-speed ripples of gravitational waves.
If researchers can track the waves as they pass through the planet, they can begin to pinpoint where such phenomena are, how many of them are in space and how they formed, said Senior Staff Specialist Brian O’Reilly, of the California Institute of Technology. It also allows them to look for objects that do not produce or reflect light, such as a black hole, he added.
“We are just another kind of telescope,” said Joe Giaime, LSU physics and astronomy professor and the observatory head.
While light that contacts objects creates a shadow, gravitational waves pass through objects relatively unchanged, he said.
If a wave passed between two people, it would increase the distance between them without either moving, Gonzalez explained.
LIGO works by shooting a laser into perpendicular mirrors, each 21/2 miles away. Scientists measure how long it takes photons from the lasers to travel the distance, and a variation in the time could be evidence of a gravitational wave, she said.
The first-generation LIGO was built in the late ’90s and early 2000s and could pick up signals from about 50 million light-years away, Giaime said. But in the vast expanses of space, researchers didn’t pick up any signals, and it became clear they would need a more sensitive device.
“We hadn’t really stood a chance with initial LIGO,” Giaime said.
The old detector was removed in 2010, and scientists have been implementing Advanced LIGO ever since with improvements to multiple systems.
The new setup is 10 times more sensitive. It will be able to detect a variation one-ten-thousandth the diameter of a proton. Increased sensitivity means scientists can troll for fainter signs from 10 times farther away in space, where there are more phenomena.
Over the summer, staff finished setting up the laser and are now working to tune the equipment. They have to make adjustments to allow for disruptions that create “noise,” or irrelevant data that can affect readings. Seismic activity from earthquakes to trains can shake the setup. O’Reilly described more esoteric issues — “shot noise, radiation pressure and quantum noise” among them.
They hope to complete the process by next year, though it will take a few more years for Advanced LIGO to reach its full potential.
Giaime isn’t sure when the device will reach its goal of detecting a gravitational wave.
“We have to be sensitive and nature has to start sending us the sources,” he said.
Gonzales hopes the discovery will come in the next few years.
“There’s a lot of different scientists working together to get the results,” she said.
About 50 people work on-site from day to day, but hundreds of scientists from over a dozen countries have collaborated on the project.
LIGO, which is funded by the National Science Foundation and operated through Cal Tech and the Massachusetts Institute of Technology, has a sister site in Richland, Washington, that also will continue combing the skies when it finishes upgrading. There are talks of installing another sister facility in India.
Livingston was chosen because it had enough available land in a rural site near a university and because it was far from the other facility in Washington, Giaime said.
“We’re definitely one of the weirdest things in Livingston Parish,” O’Reilly said.
Gravitational waves of a different sort have been making a splash in recent months. In March, a team from Harvard and the Smithsonian claimed it found evidence of the waves affecting light in the early universe, though the assertion has not been confirmed.
LIGO scientists remain interested in the potential discovery but emphasize their work is of a very different kind.
“No, it’s not a space race at all,” Giaime said.
Rather, they are interested in the present and how gravitational waves might help them map the cosmos.
“It’s really opening a window to the universe,” Gonzalez said.
“We are working on the very frontier of technology and science.”