NEWSWEEK
Albert Einstein’s theory of general relativity—which explains gravity as the product of the distortion of space and time—may not be universally applicable.
This is the conclusion of physicists from the University of Geneva (UNIGE), Switzerland, and the Paul Sabatier University in Toulouse, France, who studied data from a survey mapping the shape of hundreds of millions of galaxies from various points of cosmic history.
When the team analyzed how the mass of these galaxies distorts space-time, they found a slight deviation from Einstein’s predictions that they emerged between 5–6 million years ago.
This change coincides with an acceleration in the rate of expansion of the universe, and so may help shine a light on this puzzling phenomena.
Under Einstein’s theory of general relativity, objects with mass distort space and time—much like how your mattress would deform if you placed a bowling ball on your bed.
This deformation of the fabric of the universe, the physicist proposed, is what we experience as gravity.
The space-time distortions around objects—like, for example, planets or stars—sit in their own little “gravitational wells”.
And when light passes through these wells, it is bent as if passing through a magnifying glass, in a process known as gravitational lensing.
This aspect of general relativity was verified in 1919, four years after the concept was published, via experiments partly undertaken during a solar eclipse.
British astronomers Arthur Stanley Eddington and Frank Watson Dyson showed that the sun’s gravity well deflected light from distant stars (which were visible while the sun was blocked out during the eclipse) exactly as general relativity predicted.
This was around twice that of the deflection anticipated by Newtonian physics, which did not account for the curvature of time as well as of space.
The question remains, however, as to whether Einstein’s predictions remain correct on a universal scale.
In their study, the researchers used data from the Dark Energy Survey. This project is measuring the accelerating expansion of the universe, which is thought to be driven by a mysterious, invisible force dubbed dark energy…
