Neptune Discovered: Math Predicts a New World
French mathematician Urbain Le Verrier and British mathematician John Couch Adams predicted Neptune's existence through gravitational calculations before German astronomer Johann Gottfried Galle spotted it in 1846. This triumph proved Newton's laws could map the solar system with such precision that a planet remained invisible to the naked eye yet undeniable on paper.
September 23, 1846
180 years ago
Key Figures & Places
What Else Happened on September 23
Caligula elevated his late sister Drusilla to the status of a goddess, the first time a Roman woman received such an honor. By granting her divine rank, he asse…
Pope Callixtus II and Holy Roman Emperor Henry V signed the Concordat of Worms to resolve a decades-long struggle over who held the power to appoint bishops. Th…
French forces decimated an English fleet off the coast of Arnemuiden, capturing five ships and seizing a massive cargo of wool. This clash introduced gunpowder …
The English ship Christofer carried three iron cannons and one hand gun into the harbor at Arnemuiden in 1338 — and changed naval warfare before anyone knew wha…
Mongol forces crushed a Ming Chinese army at the Battle of Kherlen, securing their second major military triumph since the collapse of the Yuan Dynasty. This vi…
Yorkist forces under the Earl of Salisbury routed a larger Lancastrian army at Blore Heath in Staffordshire, the first major bloodshed of the Wars of the Roses.…
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