The way the Earth changes its tilt. See 'A Brief History of Climate Change'.
Obliquity
Fact of the Day
A third of Hungarians are thought to have died during the Mongol invasions of the 13th century.
Quote of the Day
"Don't put your trust in revolutions. They always come around again. That's why they're called revolutions.
"
~ Terry Pratchett
On This Day
1787 The 'First Fleet' of 11 ships carrying convicts to Australia left England.
1888 Slavery was abolished in Brazil.