A detector buried a kilometre underground in Japan may have caught the faintest signal ever recorded: the combined whisper of every supernova that has ever exploded across the entire universe, a background hum of stellar death that scientists have been straining to hear for decades

Super-Kamiokande has reported the first indication of the diffuse supernova neutrino background, a predicted flux of neutrinos built up from core-collapse supernovae across cosmic history. The result was announced by the collaboration on 26 June 2026, a day a…