Ultraviolet B radiation converts skin precursors into vitamin D, essential for calcium metabolism and bone health.

Friedrich Nietzsche wrote “God is dead” in *The Gay Science* (1882), reflecting on decline of religion in modern society.

Alfred Wegener proposed continental drift in 1912, suggesting continents once formed a supercontinent Pangaea, later separating.

The Black Death (1347–51) killed about one-third of Europe’s population, spread by fleas on rats. This is a well-documented historical or scientific.

Yuri Gagarin, a Soviet cosmonaut, became the first human in space on April 12, 1961, aboard Vostok 1.

Jupiter rotates in under 10 hours, making it the fastest-spinning planet, contributing to its flattened shape at the poles.

The Battle of Hastings saw William the Conqueror defeat King Harold II, bringing Norman rule and cultural transformation to England.

Gold has atomic number 79 and symbol Au; its rarity and properties have made it historically valuable for currency and jewelry.

Magna Carta established legal limits on King John of England, becoming a foundation for constitutional law and parliamentary rule.

Amelia Earhart completed her solo flight across the Atlantic in 1932, becoming a symbol of aviation and women’s achievement.