The Secret of Three Notes: Supernova to Reveal Neutrino Mass Ordering ✛ ✦

Neutrinos are three particles with three masses, like the three notes of a chord. Their order changes the 'melody' of cosmic events, but which sound is correct remains unknown. The answer will come from the next supernova: in the first milliseconds, the neutrino signal will indicate whether the masses increase or decrease. Detectors like DUNE and Hyper-Kamiokande will catch this difference, upon which a crucial mystery depends: why matter survived the Big Bang while antimatter vanished.

When a star collapses, almost all energy goes into neutrinos (an idea of Pauli). If the core exceeds the Chandrasekhar limit, a black hole appears, otherwise a neutron star. The explosion scatters cosmic dust to form new stars, while chaos reigns with entropy — a measure of disorder. The neutrino 'melody' connects dark matter and the expansion of the universe, and its echo is heard in the cosmic microwave background. The method traces back to Wheeler.