While the crew of Futurama figured out what dark matter is, and the sinister secret behind how it was harnessed as starship fuel, scientists haven’t been as successful. What we do know is that it makes up nearly a quarter of the universe while all but 4% of the remaining mass is attributed to a force called dark energy, so we can’t just ignore it while we study the cosmos. And with so many experiments ruling out hypothesis after hypothesis as to what these two might be, some researchers are asking whether dark matter exists and if instead of running in circles, we should try to answer a question that’s also stumped us for a long time: how does gravity work?