Scientists may have finally cracked a decades-long mystery surrounding the fabric of the cosmos.
As much as 95 percent of the known universe is “missing,” meaning it cannot be explained by scientists and a newly discovered “dark fluid” could solve the conundrum.
The material, which scientists say possesses negative mass, brings together dark energy and dark matter into a single phenomenon.
It has long been thought that dark matter and dark energy – invisible substances that have never been observed by scientists – make up the parts of the universe that modern physics cannot measure or explain.
But until now, scientists had no way to describe just how the pair fits into the theoretical jigsaw of the cosmos.
James Farnes, who led the team at the University of Oxford, said: “We now think that both dark matter and dark energy can be unified into a fluid which possesses a type of ‘negative gravity.’
“If real, it would suggest that the missing 95 percent of the cosmos had an aesthetic solution: We had forgotten to include a simple minus sign.” The findings were published in Astronomy & Astrophysics.
Our current model of the universe, called LambdaCDM, tells us nothing about what dark matter and dark energy are like physically.
We only know about them because of the gravitational effects they have on other, observable matter.
Scientists had previously suggested that the existence of negative matter could bring dark matter and energy together into one unifying theory.
The idea was ruled out because it was thought the material would become less dense as the universe expanded, something that was not supported by observations involving dark matter.
But the Oxford team added a new ingredient to the model: A “creation tensor,” which allowed for the continuous build-up of negative masses.
This meant that as the universe expanded, the new material – the negative mass fluid – did not become diluted and so slotted into calculations involving dark matter.
Computer simulations run by the team provided the first correct prediction of the behavior of dark matter halos, which are said to hold together the fabric of galaxies.
Most galaxies are rotating so rapidly they should be tearing themselves apart, which suggests that an invisible “halo” of dark matter must be holding them together.
Simulations run as part of the new study predicted the formation of dark matter halos matching ones picked out by modern radio telescopes.
Proof of Farnes’ theory will come from tests performed with cutting-edge radio telescopes, including the Square Kilometre Array (SKA), which the University of Oxford is helping to build.