Wave

Enhanced laser interferometer gravitational-wave observatory (LIGO) detectors, a US National Science Foundation (NSF)-funded project, have detected gravitational waves in space for the first time.

This confirms the prediction of Albert Einstein’s general theory of relativity after a hundred years.

LIGO researchers observed the merger of a pair of black holes through a transient gravitational-wave signal, more than a billion light years from Earth.

This is the first observation of a binary black hole merger that will offer information about their origins and the nature of gravity that cannot be found otherwise.

According to physicists, the detected gravitational waves were produced during the last fraction of a second of the union of two black holes to create a single,massive spinning black hole. This merger of two black holes had been predicted before, but never detected.

The latest discovery by two LIGO observatories has been published in the journal Physical Review Letters.

It was prepared by the LIGO Scientific Collaboration (LSC), which is a collaboration of several physics institutes and research groups worldwide dedicated to the search for gravitational waves using input from two LIGO detectors in the US.

"The field of gravitational wave astronomy is now a reality."

Known to be the first observation of gravitational waves, the new LIGO discovery was made by measuring tiny turbulences the waves make as they pass through the Earth.

During the 1970s and 80s, Joseph Taylor, Jr and his colleagues first demonstrated the existence of gravitational waves.

LIGO Laboratory executive director David Reitze said: "Our observation of gravitational waves accomplishes an ambitious goal set out over five decades ago to directly detect this elusive phenomenon and better understand the universe, and, fittingly, fulfills Einstein’s legacy on the 100th anniversary of his general theory of relativity."

The LIGO observatories were recently upgraded to an advanced level called Advanced LIGO, which increases the sensitivity of the instruments compared to the first generation LIGO detectors.

Louisiana State University physics and astronomy professor Gabriela Gonza´lez said: "This detection is the beginning of a new era.

"The field of gravitational wave astronomy is now a reality."

LIGO scientists estimate the black holes were 29 and 36 times the mass of the Sun, and the event took place 1.3 billion years ago.

Scientists added that three times the mass of the Sun was converted into gravitational waves in a fraction of a second with a peak power output 50 times that of the whole visible universe.

Max Planck Institute for Gravitational Physics, Hannover director professor Karsten Danzmann said: "Scientists have been looking for gravitational waves for decades, but we have only now been able to achieve the incredibly precise technologies needed to pick up these very, very faint echoes from across the universe."

Image: Gravitational waves have been observed in space. Photo: courtesy of Caltech / MIT / LIGO Laboratory