Our universe may in fact be a computer simulation, former Astronomer Royal Lord Martin Rees has said.
Speaking at the Wired 2013 conference in London, Rees said that in a "post-human" world, it would be possible - perhaps even likely - that simulations on the scale of worlds or universes could be created.
Indeed, a thought experiment has long held that if such a thing were possible, it is arguably more likely mathematically that we're inside one of the many simulations and not the single 'real' universe.
Lord Rees, who is also the former president of the Royal Society and former master of Trinity College, Cambridge, admitted it was "unwise" to speculate about the far future.
But forgoing his own advice, for a moment, he offered some thoughts about the future of mankind - including the prediction of advanced simulations containing their own form of life.
"Post-human intelligence will develop hypercomputers with the processing power to simulate living things," he said at the conference. "Even entire worlds, entire universes."
"So perhaps we are all 'artificial life' in a virtual universe."
Rees said that such technology might be beyond humanity, but it might be achievable by our successors.
"Post-humans will evolve from our species not via natural selection but by design. They could be silicon-based, or they could be organic creatures who had won the battle with death, or perfected the techniques of hibernation."
Rees also touched on the future of space travel, whether humans will ever reach Mars, and whether or not super-intelligent alien life might already exist.