Krakatoa 1883: The Loudest Sound in Human History

The loudest sound in the history of the world. August twenty-seventh, 1883. A small volcanic island between Java and Sumatra, called Krakatoa, tears itself apart. You are a sailor on the Norham Castle, forty miles away. When the island goes, the sound does not just reach you. It ruptures the eardrums of half the crew. Forty miles away. The captain writes it in the log. And this is not a figure of speech. A sound this loud stops being sound. At the source it passes the limit of what air can carry, and becomes a shockwave you can see, racing out across the ocean. Three thousand miles away, near Madagascar, an officer on Rodrigues Island hears what he swears is a naval battle, heavy guns, over the horizon. There is no battle. It is Krakatoa, a quarter of the way around the planet. And here is the part we can prove. The pressure wave from the blast raced around the entire Earth, and then kept going. Barometers in fifty cities, from Calcutta to Washington, twitched every thirty-four hours as it passed. Again. And again. Three to four times around the globe, in each direction. We did not work that out later. They wrote it down in 1883, in the Royal Society report. The eruption killed more than thirty-six thousand people, almost all by the sea it threw at them. But the sound went around the world four times, and then it was gone. Comment RECEIPTS and we will send you the Royal Society records.