Scientists discover that universe is awash in gravitational waves
The Hindu
Scientists unveiled evidence that gravitational waves, the ripples in the fabric of space-time, are permeating the universe at low frequencies - creating a cosmic background hum
Scientists on Wednesday unveiled evidence that gravitational waves, the ripples in the fabric of space-time predicted by Albert Einstein more than a century ago, are permeating the universe at low frequencies - creating a cosmic background hum.
The new findings show that space is awash with these gravitational waves, which oscillate over years or longer and appear to originate primarily from pairs of supermassive black holes spiraling together before merging.
"Gravitational waves are created by astronomically dense objects in our universe, usually in orbit around each other. The gravitational waves actually stretch and compress space-time itself as they travel through the universe," said Oregon State University astrophysicist Jeff Hazboun, a member of the scientific collaboration that conducted the research and lead author of one of the papers describing the findings in the Astrophysical Journal Letters.
Einstein in 1916 proposed the existence of gravitational waves as an outgrowth of his ground-breaking general theory of relativity, which depicted gravity as the distortion of space and time by matter. Until their detection in 2016, scientists had found only indirect evidence of their existence, beginning in the 1970s.
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Objects called pulsars - the extremely dense cores of exploded stars that spin at the speed of kitchen blenders - were crucial in the new research. Sixty-eight pulsars were used in gathering the evidence.
"We see the passage of the gravitational waves as changes in the arrival time of pulses from an array of pulsars in our galaxy," Hazboun said.