In honor of the centennial anniversary of Albert Einstein’s general theory of relativity, members of the National Science Foundation and Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO) in Livingston announced Thursday the detection of gravitational waves arriving at Earth, thereby confirming the existence of gravitational waves as predicted in the famed scientist’s 1916 theory.
LIGO, an experiment co-founder Kip Thorne called a “half-century quest,” signifies two identical detectors strategically placed in Hanford, Washington and Livingston, Louisiana. The detectors record vibrations in space time for everyone to hear.
David Reitze, LIGO executive director at the California Institute of Technology, said as time progressed, the frequency increased.
“This is the first time the universe has spoken to us through gravitational waves,” Reitze said.
According to a video from the presentation, gravitational waves, or “dynamical perturbations in the fabric of space time,” stretch space in one direction and compress it in the other. These waves are produced by two colliding black holes, Reitze said.
As the small black holes spin around one another, they slowly morph into one larger hole, thus creating a binary black hole merger.
He said the burst of gravitational waves, which stretch each detector by approximately 1/1000 the diameter of a proton, travel 1.3 billion years until they reach Earth.
NSF director France Cordova said her organization’s 1992 funding of LIGO marked the largest investment NSF made. She said her organization has funded trailblazers since the mid-1970s.
“Opening a new observational window would allow us to see our universe, and some of the most violent phenomena within it, in an entirely new way,” Cordova said.
Gabriela Gonzalez, LIGO scientific collaboration spokesperson from the University, said the A-shaped detectors, spanning 4 kilometers on each arm, starting showing promising signals Sept. 14 from the Livingston location when it measured distortions from the gravitational waves.
Just seven milliseconds later, Gonzalez said the same pattern was seen in Hanford.
While she said the coincidence was “remarkable,” Gonzalez also said the waveforms fall within the human hearing range.
“That’s the chirp we’ve been looking for,” she said.
Rainer Weiss, LIGO co-founder from the Massachusetts Institute of Technology, said the discovery would not have been possible had it not been for Einstein’s finding of strains in space 100 years ago.
Until Sept. 14, Thorne said humans had never seen “the ocean roiled in a storm with crashing waves.” He said the discovery prompts new searches for gravitational waves in supernovae and cosmic streams, to name a few.
Over the next decade or two, Thorne said LIGO will have four gravitational wave windows open for the universe. Reitze said the groundbreaking discovery paves the way for new technologies and possibilities.
“What’s really exciting is what comes next,” Reitze said.