Our universe is not as special as previously thought, according to new research.
A team of scientists from the UK and Australia studying “dark energy,” the mysterious force accelerating the expansion of the universe, found that varying amounts of dark energy can support life—a conclusion that goes against currently held views on the issue, and opens up the possibly that a Multiverse, if it exists, could be hospitable to life.
Current theories posit that our universe has just the right amount of dark energy to support life. Any more would cause a rapid expansion leading to the breakdown of matter before life could be formed.
However, the new study suggests that variations in the amount of dark energy only have a modest impact on star and planet formation, meaning that the conditions for support life are not as narrow as previously thought.
Cosmologists from Durham University in the UK, and Australia’s University of Sydney, Western Sydney University, and the University of Western Australia used huge computer simulations of our observed universe to examine how different levels of dark energy might affect the development of life.
In two papers published in the journal Monthly Notices of the Royal Astronomical Society, researchers found that even with dark energy levels dialed to extremely high or small amounts, life still formed.
“For many physicists, the unexplained but seemingly special amount of dark energy in our Universe is a frustrating puzzle.
“Our simulations show that even if there was much more dark energy or even very little in the Universe then it would only have a minimal effect on star and planet formation, raising the prospect that life could exist throughout the Multiverse,” said co-author Jaime Salcido, a researcher at Durham University’s Institute for Computational Cosmology, in a press release.
The researchers ran simulations under the EAGLE (Evolution and Assembly of GaLaxies and Environments) project, which is one of the most realistic simulations of the known Universe.
“We asked ourselves how much dark energy can there be before life is impossible?
“Our simulations showed that the accelerated expansion driven by dark energy has hardly any impact on the birth of stars, and hence places for life to arise. Even increasing dark energy many hundreds of times might not be enough to make a dead universe,” said co-author Dr. Pascal Elahi, Research Fellow at the University of Western Australia.
The results also cast doubt on the ability of the Multiverse theory to explain the amount of dark energy in our universe, said the researcher.
The theory that our universe is one of possibly an infinite number of possible universe, advanced in the 1980s, in part sought to explain why our universe had the “luckily small” amount of dark energy that enabled it to produce life. If there were an infinite number of realities, then chances are there would be one where the conditions were ripe to sustain life.
“The Multiverse was previously thought to explain the observed value of dark energy as a lottery – we have a lucky ticket and live in the Universe that forms beautiful galaxies which permit life as we know it,” said co-author Dr. Luke Barns, Research Fellow at Western Sydney University.
“Our work shows that our ticket seems a little too lucky, so to speak. It’s more special than it needs to be for life. This is a problem for the Multiverse; a puzzle remains.”
While the results do not rule out the Multiverse, the researchers noted that the small amount of dark energy in our cosmos should be explained by a new law of physics, yet to be discovered.
“The formation of stars in a universe is a battle between the attraction of gravity, and the repulsion of dark energy,” said co-author Professor Richard Bower at Durham University’s Institute for Computational Cosmology.
“We have found in our simulations that universes with much more dark energy than ours can happily form stars. So why such a paltry amount of dark energy in our Universe?
“I think we should be looking for a new law of physics to explain this strange property of our Universe, and the Multiverse theory does little to rescue physicists’ discomfort.”