How a 1987 Supernova Proved Neutrinos Travel Faster Than Light—Sort Of

In the predawn hours of February 23, 1987, three underground instruments on three continents caught a whisper from a dying star 168,000 light years away — a whisper that arrived before the star's own light did. The particles were neutrinos, nearly massless and nearly invisible, and their early arrival confirmed what physicists had long theorized: that the true engine of a stellar death is not the blinding flash we see, but an invisible torrent of energy that escapes the collapsing core in seconds, long before light can claw its way to the surface. That handful of detections — fewer than thirty