It was arguably one of the biggest physics discoveries of all time, let alone in 2016. And yet the scientists who discovered gravitational waves went hom empty handed when the Royal Swedish Academy of Sciences announced the 2016 Nobel Prize in Physics.

Instead, the prize went to researchers working on exotic matter, and a shocking upset that most didn’t see coming. The founders of the Laser Interferometer Gravitational-wave Observatory were seen as the easy winners of this year’s prize after the bombshell February announcement that they had found ripples in spacetime from the merger of two black holes a billion years ago.

But they didn’t win it. Why? Perhaps it’s the fact that more than a thousand scientists work on LIGO, and a Nobel Prize can only be awarded to a maximum of three scientists. Of course, there were three founders of LIGO.

It’s also possible that the discovery came too late in the year to win this year’s awards, as the news was not publicly confirmed until Feb. 11 despite being rumored about back in September.

“This year’s Laureates opened the door on an unknown world where matter can assume strange states,” reads a RSAS statement on the winners. “They have used advanced mathematical methods to study unusual phases, or states, of matter, such as superconductors, superfluids or thin magnetic films. Thanks to their pioneering work, the hunt is now on for new and exotic phases of matter. Many people are hopeful of future applications in both materials science and electronics.

“The three Laureates’ use of topological concepts in physics was decisive for their discoveries. Topology is a branch of mathematics that describes properties that only change step-wise. Using topology as a tool, they were able to astound the experts. In the early 1970s, Michael Kosterlitz and David Thouless overturned the then current theory that superconductivity or suprafluidity could not occur in thin layers. They demonstrated that superconductivity could occur at low temperatures and also explained the mechanism, phase transition, that makes superconductivity disappear at higher temperatures.”