It’s embarrassing, but astrophysicists are the first to admit it. Our best theoretical model can only explain 5 percent of the universe. The remaining 95 percent is famously made up almost entirely of invisible, unknown material dubbed dark energy and dark matter. So even though there are a billion trillion stars in the observable universe, they are actually extremely rare.
The two mysterious dark substances can only be inferred from gravitational effects. Dark matter may be an invisible material, but it exerts a gravitational force on surrounding matter that we can measure. Dark energy is a repulsive force that makes the universe expand at an accelerating rate. The two have always been treated as separate phenomena. But my new study, published in Astronomy and Astrophysics, suggests they may both be part of the same strange concept — a single, unified “dark fluid” of negative masses.
Negative masses are a hypothetical form of matter that would have a type of negative gravity — repelling all other material around them. Unlike familiar positive mass matter, if a negative mass was pushed, it would accelerate towards you rather than away from you.
Negative masses are not a new idea in cosmology. Just like normal matter, negative mass particles would become more spread out as the universe expands — meaning that their repulsive force would become weaker over time. However, studies have shown that the force driving the accelerating expansion of the universe is relentlessly constant. This inconsistency has previously led researchers to abandon this idea. If a dark fluid exists, it should not thin out over time.