A new theory unifies the dark energy and dark matter that make up the vast majority of the universe. In this new model, the “dark fluid” exerts the gravitational force of the former and the repulsive force of the latter.

“Dark” refers to how these energies, matter, and fluid cannot be detected using electromagnetic means. They can only be evaluated based on their gravitational effects.

Dark matter is said to comprise most of the universe. Dark energy, on the other hand, is causing the universe to expand faster and faster.

University of Oxford (Oxford) researcher Jamie Farnes believes that these two seemingly separate and unrelated things are actually the same thing. He proposes dark fluid as the unifying term for this collection of negative masses.

(Related: Scientists are actually losing ground on their understanding of dark matter, as new research contradicts previous findings.)

Dark fluid is constantly being produced to fill the gaps of the universe

In his recently-published paper, Farnes modifies Einstein’s theory of gravity to explain the existence and the continuous creation of negative masses. This “matter creation” has previously been proposed by the discredited Steady State model of the universe.

While positive matter is most certainly not being constantly churned out to fill the gaps of the expanding universe, the same might not hold true for negative masses. Farnes suggests that dark fluid is constantly being produced so that its negative matter is never too thinly spread. That means it can behave like dark energy while also being made of dark matter.

Farnes says he ran this theoretical model on a computer. He hoped to find out if his idea could describe the physical characteristics of dark fluid.

Dark matter was originally conceived to explain why galaxies that are rotating much faster than expected are not tearing themselves apart. The force of this invisible matter is believed to prevent those galaxies from breaking apart.

The 3D computer model of dark liquid shows that the repulsive force of the fluid could perform the same job as dark matter. The negative masses are attracted to the gravitational force of the positive mass galaxy.

As the dark fluid draws closer to the galaxy, the negative mass applies stronger repulsive forces on the positive mass. The galaxy responds by speeding up its rotation.

Negative masses are easier to understand than you may think

Farnes says that negative masses are not as strange as they would seem to be. Even ordinary humans who are made of positive matter can grasp the idea of something invisible but palpable.

For example, a bubble of air is made of positive matter, the gases and particles that comprise the air. But if you put the air bubble inside a liquid, it can actually be described in terms of having negative mass. And some artificially-generated particles have also behaved as if they possessed negative mass.

The dark fluid model offers to resolve several long-standing issues in the field of physics. String theory, for instance, states that empty space possesses negative energy. This is compatible with negative mass dark fluid, which exerts the same repulsive force as dark energy.

String theory also happens to be the best bet at merging quantum physics and Einstein’s theory of general relativity. What researchers have seen of the universe seem to disprove string theory – but that only applies to the observable part.

Another problem that can be solved by the dark fluid theory is the expansion of the universe. In a dark fluid universe, the Hubble constant changes over time, which explains why measurements of the aforementioned constant keep changing.

Sources include:

LiveScience.com

ARXIV.org