Here is an uncomfortable fact. Quantum field theory — arguably the most successful framework in all of science — predicts that empty space should be crackling with so much energy that the cosmological constant, the number describing the universe's accelerating expansion, should be almost unimaginably large. Observations, however, tell a very different story. The measured value is fantastically, stubbornly tiny.

The gap between prediction and reality is so vast that physicists call it one of the worst mismatches in the history of science. How can a theory so brilliant be so spectacularly wrong? Now a team at Brown University in Rhode Island thinks it may have found a surprising answer — and the clue came from an entirely different corner of physics. Stephon Alexander, Aaron Hui, and Heliudson Bernardo noticed that the mathematics describing a proposed ground state of quantum gravity, called the Chern-Simons-Kodama state, looks strikingly similar to the mathematics behind the quantum Hall effect.

This is a condensed-matter phenomenon observed in laboratories across the world, from Tokyo to Zürich, in which electrical conductance locks onto precise values and refuses to budge — even when the material is full of imperfections.