Letter from Birmingham Jail

Recreation of Martin Luther King Jr. 's cell in Birmingham Jail at the National Civil Rights Museum

Langton's ant after 11,000 steps. A red pixel shows the ant's location.

Temperature map of the cosmic microwave background measured by the Planck spacecraft

01The pigeons roosting inside the horn antenna were trapped and relocated twice before the engineers accepted the hiss was cosmic.
02Penzias and Wilson won the 1978 Nobel Prize in Physics — accidentally, while testing satellite communication equipment.
03Princeton cosmologist Robert Dicke had been building a detector specifically to find this radiation; Penzias called him first, and Dicke told his team: 'We've been scooped.'

Written in margins of smuggled newspaper and on scraps of paper, King's letter from Birmingham Jail on April 16, 1963 answered eight clergymen by name. It circulated in millions of copies within the year.