The accident of life...

• 15 billion years ago accident of space-time, matter and energy happened (pre-existence apparently unconceivable).

• The earth happened 4.5 billion years ago. And the ozone layer (which protects it) happened 3 billion years ago.

• Life happened 1.5 billion years ago. Humans (homo sapiens - HS) evolved 0.45 billion years ago.

• The biosphere is the only known habitat for HS.