whales

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.

Humpback whales sing songs that can last 30 hours and travel hundreds of kilometers. Fin whales produce calls at 20 Hz — below the threshold of human hearing — that propagate across entire ocean basins. Sperm whales use click-based dialects specific to family groups. Whale communication is not simple signaling. Biologists now argue it bears hallmarks of culture, the transmission of learned behaviors across generations.