Einstein’s gravity ripples detected
WASHINGTON — In an announcement that electrified the world of astronomy, scientists said Thursday that they have finally detected gravitational waves, the ripples in the fabric of spacetime that Einstein predicted a century ago.
Some scientists likened the breakthrough to the moment Galileo took up a telescope to look at the planets.
The discovery of these waves, created by violent collisions of massive celestial objects, excites astronomers because it opens the door to a new way of observing the cosmos. For them, it’s like turning a silent movie into a talkie because these waves are the soundtrack of the universe.
“Until this moment we had our eyes on the sky and we couldn’t hear the music,” said Columbia University astrophysicist Szabolcs Marka, a member of the discovery team. “The skies will never be the same.”
An all- star international team of astrophysicists used a newly upgraded and excruciatingly sensitive $ 1.1 billion set of twin instruments known as the Laser Interferometer Gravitational- wave Observatory, or LIGO, to detect a gravitational wave from the crash of two black holes 1.3 billion light- years from Earth.
To make sense of the raw data, the scientists translated the wave into sound. At a news conference, they played what they called a “chirp” — the signal they heard on Sept. 14. It was barely perceptible even when enhanced.
Some physicists said the finding is as big a deal as the 2012 discovery of the subatomic Higgs boson, sometimes called the “God particle.” Some said this is bigger.
“It’s really comparable only to Galileo taking up the telescope and looking at the planets,” said Penn State physics theorist Abhay Ashtekar, who wasn’t part of the discovery team. “Our understanding of the heavens changed dramatically.”
Gravitational waves, first theorized by Albert Einstein in 1916 as part of his theory of general relativity, are extraordinarily faint ripples in space- time, the hard-to-fathom fourth dimension that combines time with the familiar up, down, left and right. When massive objects like black holes or neutron stars collide, they send gravity ripples across the universe.
Scientists found indirect proof of the existence of gravitational waves in the 1970s — computations that showed they ever so slightly changed the orbits of two colliding stars — and the work was honored as part of the 1993 Nobel Prize in physics. But Thursday’s announcement was a direct detection of a gravitational wave.