The Universe is likely to continue expanding forever, according to research out Friday which offers new insights into the mysterious “dark energy” that keeps it growing.
A team of astronomers has used a distant galaxy as a cosmic “magnifying glass” to measure dark energy more precisely than before, with results that appear to confirm predictions that it will continue to drive the expansion of the Universe indefinitely.
The findings, published in the journal Science, suggest that all the matter in the Universe will gradually be drawn apart until all that remains is a cold and inert cosmic desert.
Only about 4 percent of the mass of the Universe is made up of visible matter, with another 24 percent composed of dark matter which can be detected indirectly from its influence on normal matter, but not seen. Another 72 percent is the dark energy -- something more mysterious still, which is known from its effects on the observed expansion of the Universe.
In the new research, the section of news in The Astronomical Research Center (A.R.C) mentioned that a team led by Professor Eric Jullo, of NASA’s Jet Propulsion Laboratory in Pasadena, California, used the Hubble Space Telescope to examine how light from 34 distant galaxies is distorted as it passes around a bright galaxy cluster called Abell 1689.
The way in which the light is bent depends on three factors: the distance at which it was emitted, the mass of Abell 1689, and the nature of dark energy. As the first two were known, from observations by the European Southern Observatory’s Very Large Telescope, the “gravitational lensing” effect of the galaxy cluster could be used to measure the extent of dark energy.
Priyamvada Natarajan, of Yale University, a member of the astronomy team, said that the results supported the continued expansion of the Universe. “The content, geometry and fate of the Universe are linked, so if you can constrain two of those things you learn something about the third,” he said.
Jullo said the gravitational lensing technique would offer further insights into the nature of dark energy.
“We have to tackle the dark energy problem from all sides,” he said. “It’s important to have several methods, and now we’ve got a new, very powerful one.
“What I like about our new method is that it’s very visual. You can literally see gravitation and dark energy bend the images of the background galaxies into arcs.”
Natarajan said: “We can now apply our technique to other gravitational lenses. We’re exploiting a beautiful phenomenon in nature to learn more about the role that dark energy plays in our Universe.”