The Crab Nebula, a stellar explosion, a little hard to put back into an ordered state. Photo: Robert Sullivan/ Hubble – creative commons @flickr.com

That brilliant and entertaining atheist Steven Pinker has defined ‘the ultimate purpose of life, mind, and human striving: to deploy energy and information to fight back the tide of entropy and carve out refuges of beneficial order.’

That might need a bit of explaining, not least to me. Entropy is, crudely, the measure of disorder in the universe. A low-entropy state is an ordered state; high entropy is a  disordered one. Because disorder is much more likely than order, disorder (high entropy) tends to be what everything leads to.