Dark energy is much more complex than you think.

Scientists have always been uncertain about the expansion of the universe. One of the theories suggests that it will continue to expand forever. On the other hand, some scientists believe that a time will come when it will collapse into a tiny speck. Timm Wrase, a Physicist at the University of Vienna, published a study in June 2018 which indicated that infinite expansion is impossible. Given the fact that the theory of continuous expansion is quite popular in the scientific community, this research created huge waves. Wrase acknowledged that by saying,

“People get very, kind of, emotional about it because if it’s true and [is] discovered, it would be spectacular.”

The idea that the universe will not expand forever and will collapse into the size it was before the Big Bang didn’t survive for too long as the scientists found problems with it almost immediately. Wrase himself realized that there is a massive hole in this argument and his team presented another separate study to verify that. The paper published in the journal Physical Review D mentioned that the original conjecture of the researching team couldn’t be true because the existence of the Higgs boson can’t be explained through that. Thanks to the Large Hadron Collider, scientists have a unanimous agreement that this amazing particle does exist.

The Higgs boson is an elementary particle in the Standard Model of Particle Physics. It is produced by the Quantum Excitation of the Higgs field. The name of Higgs boson comes from Peter Higgs who suggested the existence of this particle in 1964 along with 6 other scientists. In 2013, both Higgs and Francois Englert were awarded Nobel Prize in Physics for their remarkable theoretical predictions.

Despite their recent paper, Wrase told the world that the theory of collapsing-universe could well be possible by making some theoretical adjustments to it. According to the conventional, ever-expanding theory, dark energy pushes the universe outwards at a constant rate. Contrary to that, the researching team of Wrase showed that this unseen force changes over time. Wrase elaborated that the theory of everything (string theory) must incorporate dark energy in order to offer a viable explanation of the universe.

Wrase compared this dark energy with a ball in a landscape of mountains and valleys. If we place a ball on top of a mountain, it will start rolling down even after a slightest of pushes. On the other hand, a ball is in a stable universe and poses less energy while it is residing in a valley. He mentioned that the believers of the string theory long assumed that the ball is staying in the valleys all the time as it is not changing through time. However, the conjecture put forward in June suggested that the string theory could only be true if we have no mountains or valleys above sea level. Talking about that, Wrase said,

“While it is rolling downwards the dark energy becomes smaller and smaller. The height of the ball corresponds to the amount of dark energy in our universe.”

This means that the ball will continue to roll downwards due to the presence of a slope and the dark energy might start pulling the universe back to its pre-Big Bang form. This is the point where the Higgs boson jumps into the equation. Experiments have proved that this revolutionary particle can exist on these unstable mountain-tops. Wrase acknowledged that in the following words:

“We have showed that such unstable mountain tops have to exist.”

Cumrun Vafa, a Senior Author of the paper from June who is a String Theorist at the Harvard, agreed that unstable universes did create some difficulties for them. Having said that, he claimed that the revised conjecture will tackle all the limitations pointed out by Wrase and his colleagues.

In response to that, Wrase explained that the revised conjecture will not put us in a stable universe because it only proves the existence of mountaintops and fails to incorporate stable valleys. He stressed the fact that the dark energy will still change in the revised version of the conjecture. Eventually, Vafa agreed to him and expressed hope that the satellites may offer some sound experimental evidence about the change of the dark energy in the coming years.