A B-25 bomber airplane crashed into the 79th floor of the Empire State Building on July 28, 1945.
Clocks made before 1660 had only one hand - an hour hand.
Leonardo da Vinci was dyslexic, and he often wrote backwards.
In 1982, a high school student from Los Angeles, California unscrambled the Rubik's Cube in 22.95 seconds.
Grenades were invented in China over 1,000 years ago.