Gravitational lens reveals dark energy
Astronomers may have found a way to better understand dark energy, by observing the way gravity bends light reaching the Earth.
By peering at the distant reaches of the universe through a galactic magnifying lens, astronomers may have found a way to better understand mysterious dark energy, which is thought to be speeding up the expansion of the cosmos.
Though scientists don't know what dark energy is – nor have they proven definitively that it exists – they think it is the force causing galaxies to stray away from each other at an ever-quickening pace. Dark energy is the name given to whatever stuff is permeating the universe and causing this surprising accelerated expansion..
In the new study, astronomers used a massive galaxy cluster called Abell 1689 as a giant cosmic lens to study how mass warps space and time around it. When light from even more distant galaxies passes near the cluster on its way to our telescopes on Earth, the light appears magnified and distorted because of this effect. [Photo of the cosmic lens around Abell 1689]
The researchers examined 34 pictures of these far-away galaxies, taken by the Hubble Space Telescope and ground-based observatories, to study the geometry of space-time. This property is thought to be influenced by dark energy, which makes up about 72 percent of all the mass and energy in the universe, scientists think.