The trouble is that even some simple-sounding problems (such as working out whether it is possible to cover an infinite plane with a given set of patterned tiles) are mathematically proven to be inherently noncomputable.

ECONOMIST: Computer science

And the infinite emptiness of the brilliant sky above means that on the rare occasions when an object, such as a plane or a hot-air balloon, does pass through, the bright contrast lends it such a fierce intensity that it confuses the eye.

BBC: New Mexico��s alien nation