Inside an exploding supernova, an unimaginable number of neutrinos are born — ghost particles that pass through almost everything without a trace. But when gathered together, they start influencing each other and lightning-fast changing their role — physicists call it 'flavor.' Previously, calculations of these transformations relied on a uniform medium or smoothed-out randomness. But a real supernova is like a dance floor with jerky music: matter density jumps unpredictably, and each such jolt can set the particle's next move.
The authors proposed describing this chaos as a chain dance, where each step depends on the previous one, and a random touch changes the entire motion. Mathematically, this boiled down to simple formulas without hours-long simulations. It turned out that the rhythm of the dance is set by the intermittency of matter: the sharper the density jumps, the more often neutrinos change roles. Whether they heat the star or cool it depends on which of the three neutrino types is the lightest — and that remains a mystery in physics.
Neutrinos are so light and elusive that trillions pass through us every second — and almost nobody notices.