Is it all just a dream? Speculation that reality is nothing but an illusion, or simulation, or controlled environment, has been with us for thousands of years, most recently doled out as pop culture brain candy with the likes of the US film "The Matrix". But now two respected British scientists, physicist Martin Rees and mathematician John Barrow, are questioning whether all matter and mind we know is not the creation of some mega-supercomputer somewhere.
"A few decades ago, computers were only able to simulate very simple patterns. They can now create virtual worlds with a lot of detail," Rees told AFP. "In the future, we could imagine computers able to simulate worlds perhaps even as complicated as the one we think we're living in."
Martin, an astronomer at the prestigious Cambridge University, dares a thought that could have been deemed far-fetched among serious scientists only a while back: "The question is : Could we be in such a simulation?"
In this case, the universe would not be all-encompassing but only part of an ensemble Rees and Barrow call the "multiverse".
Barrow, who also teaches a Cambridge, described in an academic article that it was long known that a civilisation slightly more advanced than our own could simulate "universes in which self-conscious entities can emerge and communicate with one another".
In a much more computer-savvy society with vastly more advanced technology, "instead of merely simulating their weather or the formation of galaxies, like we do, they would be able to go further and watch the appearance of stars and planetary systems," he added.
"Then, having coupled the rules of biochemistry into their astronomical simulations, they would be able to watch the evolution of life and consciousness."
With the same ease that we humans watch the "life cycle of fruit flies", Barrow said, the machine masters of the universe could "watch the civilisations grow and communicate with each other, argue about whether there existed a Great Programmer in the Sky who could intervene at will in defiance of the laws of Nature they habitually observed".
The theory of the Cambridge pair of scientists has not met with widespread approval among peers, however. Seth Lloyd, professor of quantum mechanical engineering at the Massachusetts Institute of Technology (MIT), pointed out such a simulation would require an "unimaginably large" computer.
Lloyd, in comments published last week in The Sunday Times, gave a jab to the duo, comparing them to a science fiction book with a cult following - Douglas Adams' "The Hitchhiker's Guide to the Galaxy", which stars a supercomputer named Deep Thought.
"The Hitchhiker's Guide is a great book but it remains fiction," Lloyd said.