Cosmic Exploration · discovery

Radioactivity

1896 · Henri Becquerel

Year
1896

Description

Uranium salts left on a wrapped photographic plate in a closed drawer, waiting for sunshine that never came, fogged the plate anyway. The energy was coming from the atom itself.

Discoverer

Referenced by

researcher

Open on the Cosmic Exploration shelf — the interactive card, the filters, and everything alongside it.

From the Discoveries database in Notion, last edited 2026-08-15. This page is the row, rendered by the build; nothing on it is written by hand.