A naturalist convinced the world that Europe was once buried under ice

In 1837, Louis Agassiz proposed that Switzerland's odd boulders, scratched rocks and U-shaped valleys weren't relics of a biblical flood but evidence of a vast ice age, when glaciers once covered much of Europe. Scientists mocked the idea at first, but Agassiz's fieldwork gradually convinced geologists that Earth had swung through repeated ice ages.

— Louis Agassiz, Études sur les glaciers — 1840 (theory first presented 1837)