Will we ever be able to cross the universe with the ease of the Enterprise? As 'Star Trek into Darkness' prepares to blast into cinemas, Astronomer Royal Martin Rees offers some answers.
The best science fiction, from H G Wells onwards, can nourish everyone’s imagination. It can widen the perspective of astronomers too – that strange breed of which I’m a member. Many of us are avid consumers of the genre – though I think we’d expect aliens, if they exist, to be far stranger, and far less humanoid, than those portrayed in Star Trek. Indeed, possibilities once in the realms of science fiction have shifted into serious scientific debate – “cyborgs” and “post-humans”, alien life, and even parallel universes.
The stupendous time spans of the evolutionary past are now part of common culture (though maybe not in the United States Bible Belt, nor in parts of the Islamic world). Most people are at ease with the idea that our present biosphere is the outcome of four billion years of Darwinian evolution. But the even longer time-horizons that stretch ahead – familiar to every astronomer – haven’t permeated our culture to the same extent. Our Sun is less than halfway through its life. It formed 4.5 billion years ago, but it’s got six billion more before the fuel runs out. It will then flare up, engulfing the inner planets and vaporising any life that might then remain on Earth. But even after the Sun’s demise, the expanding universe will continue – perhaps for ever – destined to become ever colder, ever emptier. To quote Woody Allen, “eternity is very long, especially towards the end.”