Einstein is proved once again – this time on the galactic scale

Once again, Albert Einstein's general theory of relativity stopped – this time in another galaxy.

Using data from NASA's Hubble Space Telescope and the Very Large Telescope of the Southern European Observatory, an international team of researchers discovered that gravity in a galaxy at millions of light-years behaved like predicted the famous theory of the physicist.

"It's so satisfying to use the best telescopes in the world to challenge Einstein, only to find out just how right he was," said researcher Bob Nichol of the University of Portsmouth in England.

The results of the team were published this week in the journal Science.

One property of gravity described by Einstein is that objects with a considerable mass can bend the light of distant objects. This was proven for the first time in the Milky Way during an eclipse in 1919, when astronomer Arthur Eddington saw the light deviated from a star appeared near the sun.

This phenomenon, called the "gravitational lens," can be quite dramatic when massive galaxies bend light from the galaxies behind them. This is known as "strong gravitational lens".

New research shows that Albert Einstein's general theory of relativity is true in a galaxy distant 500 million light-years away. (The Canadian Press)

Most of these strong gravitational lenses are too far away for astronomers to measure the mass of the galaxy responsible for the bending of light. But Nichol and the team decided to test the theory on one of the closest galaxies, ESO 325-G004, which is 500 million light-years away from Earth.

They measured the speed at which the stars were moving in the galaxy, which allowed them to calculate the mass of ESO 325-G004 in order to keep them in orbit (rather than throwing themselves into the air). space). They then compared the mass with the lens observed by the Hubble telescope.

Thomas Collett, astronomer at the University of Portsmouth in England and lead author of the study, explains the results.

The researchers found that the mass of the galaxy was nine percent of what the general theory of relativity predicted.

"The universe is an incredible place providing such lenses," Nichol said, "which we can use as our labs."