Scientists detect Einstein’s gravity ripples

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 space-time that Einstein predicted a century ago.

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.

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.

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.

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.