Larry Summers, Barack Obama's main economic adviser, has noted that current annualised vehicle sales of about 9m are well below the 14m necessary for replacement and rising population, while annualised housing starts are about a quarter of the rate needed to support the forming of new households.

ECONOMIST: The economy

The rate at which new businesses are forming is rising.

ECONOMIST: Venture capital

At a distance of about 400 million light-years, NGC 6240 is a prime example of a massive galaxy in which stars are forming at an exceptionally rapid rate due to a recent collision and subsequent merger of two smaller galaxies.

BBC: Black holes on collision course