A simulation of the distribution of dark matter and dark energy in space. Image: © Peter Jurik/Stock.adobe.com
A new theory suggests mysterious dark matter and dark energy could be one and the same, potentially solving a 100-year-old mystery.
Given the sheer vastness of the universe, it isn’t surprising that we still have so much to learn about how it works. Yet it is incredible to think that with 95pc of everything we see, we have no idea what it is made of.
Often referred to as dark matter and dark energy, these two definitions were created as names to give to this empty space, only definable because of the gravitational effects they have on other, observable matter.
However, a team of leading scientists from the University of Oxford has published a new theory that, if true, could finally fill in the blank space on our astrophysical map of the universe. In fact, all that was missing was for physicists to have a more ‘negative’ look at it.
While our current model of the universe, LambdaCDM, tells us nothing about what dark matter and dark energy are made from, the research team’s new theory suggests that the two are not separate things, but one and the same: a unified fluid with negative mass. If negative mass was pushed against, it would actually accelerate it towards you, rather than moving the other way.
This astonishing theory could turn our understanding of modern physics on its head, while also proving yet another correct prediction made by Albert Einstein 100 years ago.
Previously, the existence of negative matter was ruled out by physicists because it was thought this material would become less dense as the universe expands. This runs contrary to our observations that show dark energy does not thin out over time.
However, with the application of a ‘creation tensor’, negative masses can be continuously created. It demonstrates that when more and more negative masses are continually bursting into existence, this negative mass fluid does not dilute during the expansion of the cosmos.
‘We had forgotten to include a simple minus sign’
In 1918, Einstein first hinted at the existence of a ‘dark universe’ after the discovery of a parameter in his equations known as the ‘cosmological constant’, which we now know to be synonymous with dark energy.
While famously self-described as his “biggest blunder”, Einstein would later write that “a modification of the theory is required such that ‘empty space’ takes the role of gravitating negative masses, which are distributed all over the interstellar space”. This would suggest he had predicted a negative-mass-filled universe.
“This new approach takes two old ideas that are known to be compatible with Einstein’s [theory of general relativity] – negative masses and matter creation – and combines them together,” said Dr Jamie Farnes of the research team.
“The outcome seems rather beautiful: dark energy and dark matter can be unified into a single substance, with both effects being simply explainable as positive mass matter surfing on a sea of negative masses.”
The next step for the research is to prove the theory right using a powerful radio telescope and running many more computer simulations.
“If real, it would suggest that the missing 95pc of the cosmos had an aesthetic solution: we had forgotten to include a simple minus sign,” Farnes said.
