Physics

The Sound That Broke the Sky I thought I knew the story of Krakatoa. Volcanic island explodes in 1883. Loudest sound in recorded history. People heard it 3,000 miles away. The end. But the real story is stranger than that. Krakatoa didn’t just make a loud noise — it created a pressure wave so powerful that it pushed the very definition of “sound” to its breaking point. And then, for five days afterward, that wave kept circling the planet like a ghost, detectable only by the delicate instruments of 19th-century meteorologists who had no idea what they were witnessing....