Mozart wrote his first symphony at the age of 8.

Project Blue Book officially ended in 1969.

Operation CHAOS gathered intelligence on domestic protest movements in the 1960s.

The 16th Amendment authorized a federal income tax.

In Aztec mythology, the sun and moon were created when two gods threw themselves into a fire at Teotihuacan.

Ancient Norse mythology described the world as a giant tree — Yggdrasil — connecting nine different realms.

Ancient Greek athletes competed naked in the original Olympics — the word 'gymnasium' comes from the Greek for 'naked.'

The fastest recorded serve in tennis by a woman is 220 km/h by Georgina Garcia Perez.

Particles can exist in multiple states until observed.