You’ve probably heard before that the universe is expanding, but new data suggests our galaxy is actually being pushed — and scientists are unable to see what exactly is doing the pushing.
Science has long known that our galaxy, the Milky Way, and our neighboring galaxy, Andromeda, were hurtling toward the edges of the universe at great speed, but they didn’t know exactly what was causing it. Now, new research indicates that a mysterious intergalactic void, dubbed the Dipole Repeller, is actually pushing the galaxies along their path to the tune of 1.4 million miles per hour compared to the rate of the rest of the universe’s expansion. The discovery of this void was first published in Nature Astronomy, and researchers located it by creating a 3D map of our corner of the universe that tracks the galaxies’ movements. It was there where they noticed a vast, low density area of space that seemed to be dictating the journey of our galaxy.
The Dipole Repeller is a massive, non-dense area of the universe with few galaxies of its own. It measures over a billion light years across, and because of its relative emptiness and massive size, it emits an unseen force that seems to act in almost the opposite way that gravity does.
“We found a flow pattern reminiscent of streams of water that are organized by gravity to run downhill,” one of the study’s authors, Brent Tully of the Institute for Astronomy in Honolulu, told CNN. “In detail, we played a mathematical trick by inverting the sense of gravity to see where flows would terminate in this altered case. Flows ended at our Dipole Repeller.“
Scientists had previously theorized that our group of galaxies, known as the Laniakea Supercluster, was just being pulled by the gravitational force exuded by a very dense collection of galaxies 750 million light-years away known as the Shapley Attractor. Now, they believe that the push from the Dipole Repeller is just as strong as the pull from the Shapley Attractor, and both forces are working in conjunction to set our galaxy in motion.
I guess it’s good news that the Dipole Repeller is pushing us away from it at super high speed, because being swallowed up by a giant void of nothingness doesn’t really sound so great.