A way of finding out how old volcanic rock is.
Potassium/argon dating
Fact of the Day
When the computer mouse was first mentioned in a publication in 1965, it was called an 'x-y position indicator'.
Quote of the Day
"What recreation tooke I? How lawfull was it? ... Was it not affected with too much delight?
"
~ Questions from the seventeenth-century puritan guidebook for women, 'A Fountaine of Tears'
On This Day
193 Roman emperor Didius Julianus was executed by his successor, Septimius Severus. He had been emperor for a mere nine weeks, having bought the position when it was auctioned off by the Praetorian Guard.
1533 Anne Boleyn, second wife of Henry VIII, was crowned Queen of England.
1939 Naval submarine HMS Thetis sank during trials in Liverpool Bay. Ninety-nine of her crew suffocated and there were just four survivors.
1962 Adolf Eichmann, organiser of the Holocaust, was executed at midnight (between 31 May and 1 June) for crimes against the Jewish people. He had evaded capture and justice for 15 years.