The largest map of the universe ever created revealed that the universe is filled with dark energy. Then reports sprouted that dark energy and dark matter could be the result of incorrect gravitational theory. Now, physicists from Geneva, Switzerland are saying that we might not need dark energy after all and that it may just be an illusion.

The quickening pace of the universe's expansion may not be caused by dark energy, but by the collapse of matter in small regions of space. This is according to Syksy Rasanen of CERN in Geneva. He adds that the overall expansion of the universe isn't affected by the properties of small regions inside it, but in any given region of space, the force of gravity between bits of matter acts as a brake on expansion.

So with that, expansion should slow down quickly in regions with lots of matter but it will go on without changes and glitches in mostly empty regions. This difference produces the illusion of dark energy according to him. He also points out that even if the expansion rate decreases or stays about the same in every region, the average rate of expansion for the universe as a whole can increase. But Harvard-Smithsonian's Niafesh Ashfordi says that the idea is very unlikely but it is an attractive possibility.

To that, Rasanen mentions that the reason for the accelerating expansion of the universe is still open for speculation. He adds that this is just a tip of the iceberg and that more studies about dark energy (or the illusion of it) is still needed for astronomers to come up with a concrete answer.