Scientists show Einstein's theory of general relativity applies to cosmic scales

Washington, March 16 (ANI): A team led by Princeton University scientists has tested Albert Einstein's theory of general relativity to determine that it applies to cosmic scales, much beyond our solar system.

After two years of analyzing astronomical data, the scientists have concluded that Einstein's theory, which describes the interplay between gravity, space and time, works as well in vast distances as in more local regions of space.

The scientists' analysis of more than 70,000 galaxies demonstrates that the universe - at least up to a distance of 3.5 billion light years from Earth - plays by the rules set out by Einstein in his famous theory.

Ever since the physicist Arthur Eddington measured starlight bending around the sun during a 1919 eclipse and proved Einstein's theory of general relativity, the scientific world has accepted its tenets.

But until now, according to the team, no one had tested the theory so thoroughly and robustly at distances and scales that go beyond the solar system.

Reinabelle Reyes, a Princeton graduate student in the Department of Astrophysical Sciences, along with co-authors Rachel Mandelbaum, an associate research scholar, and James Gunn, the Eugene Higgins Professor of Astronomy, made an assessment.

The team used data from the Sloan Digital Sky Survey, a long-term, multi-institution telescope project mapping the sky to determine the position and brightness of several hundred million celestial objects.

By calculating the clustering of these galaxies, which stretch nearly one-third of the way to the edge of the universe, and analyzing their velocities and distortion from intervening material, the researchers have shown that Einstein's theory explains the nearby universe better than alternative theories of gravity.

The Princeton scientists studied the effects of gravity on these objects over long periods of time.

They observed how this elemental force drives galaxies to clump into larger collections of themselves and how it shapes the expansion of the universe.

According to the researchers, the results are important because they shore up current theories explaining the shape and direction of the universe, including ideas about "dark energy," and dispel some hints from other recent experiments that general relativity may be wrong.

"All of our ideas in astronomy are based on this really enormous extrapolation, so anything we can do to see whether this is right or not on these scales is just enormously important," Gunn said. (ANI)