krakatoa

On August 27, 1883, the island of Krakatoa in Indonesia exploded with a sound estimated at 310 decibels at source — the loudest sound ever produced on Earth's surface by any event in the historical record. The pressure wave circled the globe four times. It ruptured eardrums of sailors 64 kilometers away, was heard in Rodrigues Island near Mauritius 4,800 kilometers distant, and registered on barometers across the world. On January 15, 2022, the eruption of Hunga Tonga-Hunga Ha'apai produced the loudest infrasound event of the modern era, with pressure waves detectable globally. These events reveal something surprising: there is a hard physical ceiling on how loud a sound in air can ever be — 194 decibels — and Krakatoa probably exceeded it.

The asteroid that ended the Cretaceous period 66 million years ago released energy equivalent to roughly 100 million megatons of TNT — more than a billion times the bomb dropped on Hiroshima. That is not a metaphor. Scientists have calculated this from the crater geometry, the global debris layer, and the seismic signature preserved in rock. Understanding how energy scales from a hand grenade to a world-altering asteroid impact requires only arithmetic — and it reveals why some explosions leave no survivors within thousands of kilometers.