The remaining 95 percent of the universe, we currently believe, is made up of dark matter or dark energy; theoretical entities that we’re only aware of because we have observed how their gravity affects things around them.
In a recently published paper, Oxford astrophysicist Jamie Farnes has proposed that dark energy and dark matter actually combine to form a “dark fluid” with negative mass that fills the universe.
Dark matter theory began development in the 1930s and the more recent dark energy theories began around 1998. These comprise our current version of the Standard Model – also known as the Lambda-CDM model – which is our ‘best guess’ as to what makes up the remaining 95 percent of our universe that we know little to nothing about. Lambda signifies dark energy as a universal constant and CDM stands for Cold Dark Matter.
“For example, electric charges (+ and −), magnetic charges (N and S), and even quantum information (0 and 1) all appear to be fundamentally polarized phenomena,” the paper states.
It could therefore be perceived as odd that gravitational charges – conventionally called masses – appear to only consist of positive monopoles.
Farnes’ new theory is based on the, as yet, hypothetical concept of negative mass, which is permissible under Newtonian physics.
Under negative mass, the rules of the game are switched: for example, if you push an object it accelerates towards you. Dark fluid would, at least theoretically, exert negative gravity, pushing things away rather than drawing them in.
With this in mind, the observed and ongoing expansion of the universe might be explained by this ‘negative gravity’ which would then essentially render galaxies of regular matter as ‘air bubbles’ trapped in a cosmos of this dark liquid.
“Previous approaches to combining dark energy and dark matter have attempted to modify Einstein’s theory of general relativity, which has turned out to be incredibly challenging,” says Farnes.
“This new approach takes two old ideas that are known to be compatible with Einstein’s theory – negative masses and matter creation – and combines them together. 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.”
“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.”
Farnes plans to use the Square Kilometer Array (SKA) telescope to compare existing observations of the universe with his own theorized predictions to test whether his dark fluid theory stands up to questioning.