While the findings certainly raise the specter that something other than general relativity runs the world, Li and his team emphasize they certainly do not claim to prove f(R) gravity is real, or disprove general relativity. The study’s simulations are just that: simulations. A “fifth force” might really exist and influence how things form in the universe, but until we have observations or data that prove such interactions are real, we’re just theorizing. The simulations themselves are built based on the data we’ve collected so far, and “one has to bear in mind that galaxy formation is an actively advancing research field, and there are still things which are uncertain,” says Li. False signals we’ve measured, holes in data, and other uncertain variables could easily produce flawed simulations. And just because we’ve never observed dark energy yet, doesn’t mean it’s cancelled.