A way of finding out how old volcanic rock is.
Potassium/argon dating
Fact of the Day
Both England and Russia imposed a tax on beards in the sixteenth and seventeenth centuries, making having a beard a status symbol.
Quote of the Day
"They are well named, for they have the countenance of angels, and as such should be coheirs with the angels in heaven.
"
~ Pope Gregory I on the Angles, recorded by Bede
On This Day
1282 The last native Prince of Wales, Llewelyn ap Gruffydd, died
1688 King James II tried to flee to France during the Glorious Revolution. He was captured but allowed to escape again later that month.
1936 Edward VIII abdicated in order to marry American divorcee and socialite Wallis Simpson.
1941 Germany and Italy declared war on the USA.
1972 Apollo 17 became the last mission to land on the moon.