'We Can Hear the Universe': Scientists Detect Gravitational Waves...

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'We Can Hear the Universe': Scientists Detect Gravitational Waves, Predicted by Einstein - by Amina Khan/ Science/ Los Angeles Times/ latimes.com

"More than a billion years ago, in a galaxy far away, two black holes surrendered to one another’s inexorable attraction and collided with such force that it disturbed the very fabric of the universe.

On Thursday, scientists announced to the world that they had detected the ripple-like gravitational waves that still course from this violent event and simultaneously confirmed a prediction made by Albert Einstein a century ago.

The detection, made with the Laser Interferometer Gravitational-Wave Observatory, known as LIGO, is the culmination of a decades-long search for signs of this elusive phenomenon — and an achievement some said was on par with the discovery of the Higgs boson, which earned its theorists a Nobel Prize in 2013.

The discovery, described in a paper in Physical Review Letters, will open a new window onto the universe, said David Reitze, executive director of LIGO, which was designed and built by researchers at Caltech and the Massachusetts Institute of Technology..."

The collision of two black holes is depicted in a computer simulation. Scientists have detected evidence of gravitational waves that resulted from such a collision more than a billion years ago. (Simulating eXtreme Spacetimes)


Richard

 

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Einstein Nailed It! Gravitational Waves Do Exist. - by Michelle Starr/ C/Net/ Sci-Tech/ cnet.com

"Scientists just discovered Einstein's ripples in the fabric of spacetime.

A century ago, Albert Einstein's General Theory of Relativity changed human understanding of space and time. From a fixed speed of light to the existence of gravitational waves, the modern era of theoretical physics was born in 1916.

On Thursday, researchers on the Laser Interferometer Gravitational-Wave Observatory project announced they have solid evidence for the existence of gravitational waves, disturbances in the fabric of spacetime.

Beyond proving Einstein's theory, the discovery brings us one step closer to a grand unified theory -- the holy grail of physics that provides an all-encompassing explanation for the universe as we know it.

A team of LIGO scientists said Thursday that they had observed gravitational waves, created 1.3 billion years ago by a collision between two black holes. These waves were detected on September 14, 2015, just three days after the facility was turned back on after a five-year upgrade.

The discovery marks not just the first time that gravitational waves have been confirmed, but the first time researchers have observed binary black holes..."

Richard

 

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How Scientists Detected Gravitational Waves for the First Time - by Deborah Netburn/ Science Now/ Los Angeles Times/ latimes.com

"Scientists have announced the first detection of gravitational waves, a finding that will give astronomers an entirely new window to the universe. But how are these waves observed and why have we never seen them before?

Gravitational waves are ripples in the space-time continuum first predicted by Albert Einstein 100 years ago.

They can be produced in many ways, but their effect on time and space is so infinitesimal that it requires the motion of massive and dense objects like black holes and neutron stars to create gravitational waves strong enough to be observed by instruments on Earth.

Scientists say the first gravitational waves to be detected were caused by two black holes, each about 30 times the mass of the sun, smashing into each other and merging.

But even then, the resulting waves were barely perceptible. For example, they caused the arm of a 2.5-mile instrument designed to measure them to lengthen by just 1/1000th the diameter of a proton.

No wonder Einstein never thought they would be measured..."

An artist's impression of gravitational waves generated by binary neutron stars. (Caltech)


Richard

 

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What is General Relativity? - by Jonathan Corum and Jennifer Daniel/ Science/ International New York Times/ The New York Times/ nytimes.com

"In 1907, Albert Einstein had his “happiest thought” — people in free fall do not feel their own weight. This simple idea laid the foundation for his general theory of relativity, which Einstein presented 100 years ago this month..." (November)



Richard

 

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Gravitational Waves Will Unlock These 'Revolutionary' Secrets of the Universe - by Dave Mosher/ Tech Insider/Business Insider/ businessinsider.com

"Ripples in the fabric of space, called gravitational waves, are careening across the universe, right through everything and everyone.

Scientists from the Laser Interferometer Gravitational-Wave Observatory (LIGO) experiment have detected some of the waves — a feat Einstein thought impossible 100 years ago — emanating from two colliding black holes.

"The skies will never be the same," physicist Szabi Marka, a LIGO collaborator based at Columbia University, said via a webcam in Washington DC to a crowded lecture hall in New York. "[Gravitational waves] will let us listen to the music of the cosmos."

Tech Insider spoke with Marka, Imre Bartos, also a physicist at Columbia and LIGO, and other researchers about the "revolutionary" new era of astronomy they say has begun.

Here are just a handful of formerly impossible things astronomers can now do with gravitational waves..."

Richard

 

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After a Century of Searching, We Finally Detected Gravitational Waves - by Liz Kruesi in Livingston, Louisian/ Science/ SmithsonianMag.com

"Two merging black holes sent out a signal 1.3 billion years ago that now confirms a key prediction of Einstein's relativity.

Scientists have heard gravity’s aria for the first time.

As two black holes spiraled toward each other and merged, they created ripples in the fabric of the cosmos in exactly the form physicists have predicted for a century: gravitational waves. Unveiled today during a suite of international press conferences, the signal paves the way for a whole new understanding of the universe.

"This is the first time the universe has spoken to us through gravitational waves. Up until now we have been deaf," LIGO Laboratory Director David Reitze, of the University of Florida, said today at a press event in Washington, D.C.

At the root of gravitational waves is Albert Einstein’s theory of gravity, which says that anything with mass warps the very fabric of space-time. When massive objects move, they create distortions in the cosmic fabric, generating gravitational waves. These waves ripple through the universe like sound waves pulsing through the air.

Einstein's theory predicts that the universe is teeming with gravitational waves, but until now we hadn’t been able to detect them, in part because the waves are exceptionally faint. But even before its upgraded instruments came officially online last year, the Laser Interferometer Gravitational-Wave Observatory (LIGO) picked up a clear signal from the powerful collision of two black holes 1.3 billion light-years away.

“To have a gravitational wave signal detected while LIGO is still not near design sensitivity in the first science run is astonishing, it’s jaw-dropping, in a good way” says Joan Centrella, who headed up the Gravitational Astrophysics Laboratory at NASA's Goddard Space Flight Center before becoming the deputy director of the Astrophysics Science Division at Goddard..."

An aerial view of the LIGO detector in Livingston, Louisiana. (LIGO Laboratory)


An excellent article on how the gravitational waves were measured.

Richard