OF COURSE you thought The Matrix was fiction. But only because you were meant to.

Do you think they're stupid enough to let us realize what's really going on?

It usually takes a conspiracy theorist to hatch such a far-fetched plot. But Nick Bostrom is a philosopher at Yale University, and he believes the Hollywood blockbuster is closer to the truth than many of us would care to believe. He's done the calculations, and he reckons that we could well be living inside a simulation.

That's right. Your life might actually be a computer program developed by a post-human society living in what you think of as the future.

In a paper submitted to the journal Mind, Bostrom has outlined exactly how he reached this chilling conclusion. The reasoning starts with one simple premise. At some point, civilisation will develop enormously powerful computers capable of mimicking what we call consciousness. And if that premise is true, the rest follows logically.

Outrageous? Not a bit of it. Look at it rationally. If it becomes technologically possible to mimic consciousness, the future can only pan out in one of three ways. First, some extinction event - maybe a powerful but deadly technology, maybe a natural disaster - will wipe us out before we actually do it. If that's true, then you can relax. What you're experiencing right now is real life.

The second scenario is also a comforting one: future humans won't be interested in running simulations. They might be too sophisticated to bother with such games, or there may be laws against it. But do either of those noble outcomes sound like a probable future of human civilisation to you? Thought not.

Which leaves us with the least palatable option: humans will one day simulate consciousness, and then go on to create simulated Universes for it to live in. If that's true then the chances are they've already done so, and you're living in one.

OK, it's just possible that you're part of the pre-simulation real world - what Bostrom calls the "original history". But given how many simulations there'll be, the probability of that is very slim. All things considered, Bostrom says, the probability that you're living in a simulation is "close to unity". "I think the argument is watertight," he says.

Any logical argument, of course, is only as good as its premises. But Bostrom has got that covered too. Imagine that we do indeed live in the "original history". How likely is it that we're on the trajectory leading to computers that can mimic consciousness?

According to Bostrom, very, very likely. All you need is to discover the particular type of computational processes that leads to what we call consciousness. "A computer running a suitable program would be conscious," Bostrom says. Roboticist Hans Moravec of Carnegie Mellon University in Pittsburgh has worked out that, whatever the "suitable program" turns out to be, emulating a mind would take about 1014 operations per second. That seems like a lot now - today's fastest computers struggle to get above 1012 operations per second - but we're heading in the right direction.

[link to www.fuchsiashockz.co.uk]