There may be a fifth force of nature, a new study suggests.

“If true, it’s revolutionary,” study lead author Jonathan Feng, a professor of physics and astronomy at the University of California, Irvine, said in a statement.

“For decades, we’ve known of four fundamental forces: gravitation, electromagnetism, and the strong and weak nuclear forces,” Feng added. “If confirmed by further experiments, this discovery of a possible fifth force would completely change our understanding of the universe, with consequences for the unification of forces and dark matter.” [8 Baffling Astronomy Mysteries]

Feng and his colleagues analyzed data gathered recently by experimental nuclear physicists at the Hungarian Academy of Sciences, who were trying to find “dark photons” — hypothetical indicators of mysterious dark matter. Dark matter is thought to make up about 85 percent of all matter in the universe, but it neither absorbs nor emits light, so it’s impossible to detect directly. (Scientists have inferred its existence from its gravitational effects on “normal” matter.)