Obesity rates among American women have stabilised, an early sign of a turning-point in the great fattening of society.

ECONOMIST: Can you be too rich?

So maybe, just maybe, the Great Smog of Beijing in recent days will mark a turning point.

BBC: Beijing smog: When growth trumps life in China

Indeed, it's arguable that if he does not do so and the president gives a great speech Thursday, Kerry's speech may be looked upon as a critical turning point in this election.

CNN: Playing to the base

The turning point was the decision taken on January 30th 1933 when Field Marshal Hindenburg, hero of the Great War, called Adolf Hitler, villain of the next, to be German Chancellor.

ECONOMIST: 20th-century history