Martin Rees

"Post-human intelligence will develop hypercomputers with the processing power to simulate living things - even entire worlds. Perhaps advanced beings could use hypercomputers to surpass the best 'special effects' in movies or computer games so vastly that they could simulate a world, fully, as complex as the one we perceive ourselves to be in."

"Maybe the search for life shouldn't restrict attention to planets like Earth. Science fiction writers have other ideas: balloon-like creatures floating in the dense atmospheres of planets such as Jupiter, swarms of intelligent insects, nano-scale robots and more."