A new model of the universe has revealed it may collapse on itself ‘remarkably’ sooner than we think.
The universe is currently expanding at an accelerated speed.
However, in as soon as 100 million years time, it could start contracting.
The acceleration of the universe could come to an end sooner than anticipated because of a ‘dynamical form of energy (known as quintessence)’.
According to the study, after finishing its acceleration phase, the universe is then expected to pass ‘into a phase of slow contraction’.
The study states: “The scenario is not far-fetched. In fact, it fits naturally with recent theories of cyclic cosmology and conjectures about quantum gravity.”
As opposed to billions of years ago, the space between galaxies has grown larger and larger, and the universe has expanded significantly within the extra space, an observation cited in multiple studies from the 1990s.
While many researchers have theorised the universe will just expand forever – due to the constant amount of dark energy per unit volume of space being a ‘cosmological constant’ – other researchers have contested the hypothesis.
Instead, some scientists have suggested dark energy is made up of something called the quintessence field and isn’t constant.
Dark energy is a theoretical form of energy which works in opposition to gravity. It accelerates the universe’s expansion.
Dark energy has been called ‘the most mysterious fact in all of physical science, the fact with the greatest potential to rock the foundations’ by Nobel laureate Frank Wilczek, from the Massachusetts Institute of Technology.
If dark energy is instead considered as having a dynamic field called quintessence, it means dark energy’s opposition to gravity may go away and the strength of its energy could weaken over time.
This would mean the universe could eventually stop expanding, or even stop expanding and then start contracting.
While the ‘big bang’ began the universe, the ‘big crunch’ could subsequently take place, with the universe collapsing on itself.
Theoretical physicist at the California Institute of Technology in Pasadena, Sean Carroll, told Nature: “If dark energy is a quintessence, its push on the expansion could slowly wither or disappear, or could even reverse to become an attractive force, causing the Universe to collapse into a ‘Big Crunch’.”
Using the model, scientists worked out how long such an occurrence may take. Features within the known universe were described in the model using actual data.
The model revealed the universe’s expansion may already be slowing – if the theory surrounding quintessence is true, that is.
It showed it could take around 65 million years for the expansion to come to a halt, and that it could begin contracting ‘less than 100 million years from now’, which the researchers reviewed as ‘surprisingly soon’.
While 100 million years may feel pretty far away – especially when what you had for breakfast yesterday morning seems like a distant enough memory – one of the researchers, Paul Steinhardt from Princeton University, New Jersey, explained how the time period isn’t really that long.
“Going back in time 65 million years, that’s when the Chicxulub asteroid hit the Earth and eliminated the dinosaurs. On a cosmic scale, 65 million years is remarkably short,” he explained.
However, it could take millions of years to prove the theory as scientists would need to analyse signals from light-years away. So there’s no need to panic just yet.
The research article, titled, ‘Rapidly descending dark energy and the end of cosmic expansion,’ is published in the Proceedings of the National Academy of Sciences of the United States of America.