But what is possible is to build many smaller dishes spaced a long way from one another, and to link them with clever computer algorithms so that they behave as if they were a single giant telescope.

ECONOMIST: The Square Kilometre Array: Divide and rule | The

In practice, a couple of widely spaced telescopes can take you a long way.

ECONOMIST: Pulsars: In a wink | The

So, for example, when it comes to forestry, there's nothing wrong with us cutting down some trees for timber, as long as you make sure that it's done in a sequence and is spaced properly so that the forest itself is sustained.

WHITEHOUSE: Town Hall in Arnold, Missouri

They created a material that excluded light with a wavelength of one millimetre (the long end of the infra-red spectrum), using an array of aluminium-oxide posts that were spaced evenly across a grid.

ECONOMIST: New-age crystals