What are gravitational waves; why Einstein was right

Researchers Thursday announced they have proof of what Albert Einstein predicted more than 100 years ago – that “gravitational waves” exist in the universe, and as they ripple through galaxies they generate enough power to distort time.

The National Science Foundation announced Thursday that for decades researchers have searched for the waves but have been unable to prove their existence. That all changed when twin instruments — one  in Louisiana and one in Washington State — found evidence of the waves when they followed a sequence of events after two black holes merged.

The discovery helps to prove Einstein's General Theory Relativity in which he predicted the existence of the waves. The waves were described by Einstein as are faint ripples in spacetime, or the theoretical fourth dimension that combines time with direction.

Wondering what the fourth dimension is? Check it out here.

The discovery of the waves, believed to be caused by violent collisions in the universe, also offers evidence that black holes do exist.

According to a story from The Associated Press, scientists worldwide see the announcement as a life-changing event.

"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."

The discovery was made by a team numbering into the thousands, according to the announcement, working at the Laser Interferometer Gravitational-wave Observatory (LIGO).

See Stephen Hawking's reponse to the discovery

The observatory used a  air of gigantic instruments in Hanford, Wash., and Livingston, La. in making the discovery. Rumors of the find had circulated for the past few months in scientific circles.

“We did it!” says David Reitze, a physicist and LIGO executive director at the California Institute of Technology (Caltech) in Pasadena. “All the rumors swirling around out there got most of it right.”

“This is transformational,” said Prof. Alberto Vecchio, of the University of Birmingham, and one of the researchers at Ligo. “This observation is truly incredible science and marks three milestones for physics: the direct detection of gravitational waves, the first detection of a binary black hole, and the most convincing evidence to date that nature’s black holes are the objects predicted by Einstein’s theory.”

Einstein’s theory reasons that an object with mass warps the curvature of space and time -- imagine a bowling ball on a trampoline bed. The mass, in this case it was two black holes colliding, stirs space and time, generating "gravitational waves" that ripple out from the collision at the speed of light.

For a timeline of the search for evidence of gravitational waves, check out this post at sciencemag.org.