Matrix-style virtual worlds 'a few years away'

Are supercomputers on the verge of creating Matrix-style simulated realities? Michael McGuigan at Brookhaven National Laboratory in Upton, New York, thinks so. He says that virtual worlds realistic enough to be mistaken for the real thing are just a few years away.

In 1950, Alan Turing, the father of modern computer science, proposed the ultimate test of artificial intelligence – a human judge engaging in a three-way conversation with a machine and another human should be unable to reliably distinguish man from machine.

A variant on this "Turing Test" is the "Graphics Turing Test", the twist being that a human judge viewing and interacting with an artificially generated world should be unable to reliably distinguish it from reality.

"By interaction we mean you could control an object – rotate it, for example – and it would render in real-time," McGuigan says.

Photoreal Animation

Although existing computers can produce artificial scenes and textures detailed enough to fool the human eye, such scenes typically take several hours to render. The key to passing the Graphics Turing Test, says McGuigan, is to marry that photorealism with software that can render images in real-time – defined as a refresh rate of 30 frames per second.

McGuigan decided to test the ability of one of the world's most powerful supercomputers – Blue Gene/L at Brookhaven National Laboratory in New York – to generate such an artificial world.

Blue Gene/L possesses 18 racks, each with 2000 standard PC processors that work in parallel to provide a huge amount of processing power – it has a speed of 103 teraflops, or 103 trillion "floating point operations" per second. By way of comparison, a calculator uses about 10 floating operations per second.

In particular, McGuigan studied the supercomputer's ability to mimic the interplay of light with objects – an important component of any virtual world with ambitions to mimic reality.

He found that conventional ray-tracing software could run 822 times faster on the Blue Gene/L than on a standard computer, even though the software was not optimised for the parallel processors of a supercomputer. This allowed it to convincingly mimic natural lighting in real time.

Not There Yet

"The nice thing about this ray tracing is that the human eye can see it as natural," McGuigan says. "There are actually several types of ray-tracing software out there – I chose one that was relatively easy to port to a large number of processors. But others might be faster and even more realistic if they are used in parallel computing."

Although Blue Gene/L can model the path of light in a virtual world both rapidly and realistically, the speed with which it renders high-resolution images still falls short of that required to pass the Graphics Turing Test.

But supercomputers capable of passing the test may be just years away, thinks McGuigan. "You never know for sure until you can actually do it," he says. "But a back-of-the-envelope calculation would suggest it should be possible in the next few years, once supercomputers enter the petaflop range – that's 1000 teraflops."

But others think that passing the Graphics Turing Test requires more than photorealistic graphics moving in real-time. Reality is not 'skin deep' says Paul Richmond at the University of Sheffield, UK. An artificial object can appear real, but unless it moves in a realistic way the eye won't be fooled. "The real challenge is providing a real-time simulation that includes realistic simulated behaviour," he says.

Fluid Challenge

"I'd like to see a realistic model of the Russian ballet," says Mark Grundland at the University of Cambridge. "That's something a photographer would choose as a subject matter, and that's what we should aim to convey with computers."

Grundland also points out that the Graphics Turing Test does not specify what is conveyed in the virtual world scene. "If all that is there is a diffusely-reflecting sphere sitting on a diffusely-reflecting surface, then we've been able to pass the test for many years now," he says. "But Turing didn't mean for his vision to come true so quickly."

McGuigan agrees that realistic animation poses its own problems. "Modelling that fluidity is difficult," he says. "You have to make sure that when something jumps in the virtual world it appears heavy." But he remains optimistic that animation software will be up to the task. "Physical reality is about animation and lighting," he says. "We've done the lighting now – the animation will follow."

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'Multiverse Theory' Holds That the Universe is a Virtual Reality Matrix

Comment: Isn't it amazing that scientists have finally had to admit that the design of the universe is so perfectly crafted so as to indicate intelligent design and yet they still try to avoid any explanation which includes the word God.

The multiverse theory has spawned another - that our universe is a simulation, writes Paul Davies.

If you've ever thought life was actually a dream, take comfort. Some pretty distinguished scientists may agree with you. Philosophers have long questioned whether there is in fact a real world out there, or whether "reality" is just a figment of our imagination.

Then along came the quantum physicists, who unveiled an Alice-in-Wonderland realm of atomic uncertainty, where particles can be waves and solid objects dissolve away into ghostly patterns of quantum energy.

Now cosmologists have got in on the act, suggesting that what we perceive as the universe might in fact be nothing more than a gigantic simulation.

The story behind this bizarre suggestion began with a vexatious question: why is the universe so bio-friendly? Cosmologists have long been perplexed by the fact that the laws of nature seem to be cunningly concocted to enable life to emerge. Take the element carbon, the vital stuff that is the basis of all life. It wasn't made in the big bang that gave birth to the universe. Instead, carbon has been cooked in the innards of giant stars, which then exploded and spewed soot around the universe.

The process that generates carbon is a delicate nuclear reaction. It turns out that the whole chain of events is a damned close run thing, to paraphrase Lord Wellington. If the force that holds atomic nuclei together were just a tiny bit stronger or a tiny bit weaker, the reaction wouldn't work properly and life may never have happened.

The late British astronomer Fred Hoyle was so struck by the coincidence that the nuclear force possessed just the right strength to make beings like Fred Hoyle, he proclaimed the universe to be "a put-up job". Since this sounds a bit too much like divine providence, cosmologists have been scrambling to find a scientific answer to the conundrum of cosmic bio-friendliness.

The one they have come up with is multiple universes, or "the multiverse". This theory says that what we have been calling "the universe" is nothing of the sort. Rather, it is an infinitesimal fragment of a much grander and more elaborate system in which our cosmic region, vast though it is, represents but a single bubble of space amid a countless number of other bubbles, or pocket universes.

Things get interesting when the multiverse theory is combined with ideas from sub-atomic particle physics. Evidence is mounting that what physicists took to be God-given unshakeable laws may be more like local by-laws, valid in our particular cosmic patch, but different in other pocket universes. Travel a trillion light years beyond the Andromeda galaxy, and you might find yourself in a universe where gravity is a bit stronger or electrons a bit heavier.

The vast majority of these other universes will not have the necessary fine-tuned coincidences needed for life to emerge; they are sterile and so go unseen. Only in Goldilocks universes like ours where things have fallen out just right, purely by accident, will sentient beings arise to be amazed at how ingeniously bio-friendly their universe is.

It's a pretty neat idea, and very popular with scientists. But it carries a bizarre implication. Because the total number of pocket universes is unlimited, there are bound to be at least some that are not only inhabited, but populated by advanced civilisations - technological communities with enough computer power to create artificial consciousness. Indeed, some computer scientists think our technology may be on the verge of achieving thinking machines.

It is but a small step from creating artificial minds in a machine, to simulating entire virtual worlds for the simulated beings to inhabit. This scenario has become familiar since it was popularised in The Matrix movies.

Now some scientists are suggesting it should be taken seriously. "We may be a simulation ... creations of some supreme, or super-being," muses Britain's astronomer royal, Sir Martin Rees, a staunch advocate of the multiverse theory. He wonders whether the entire physical universe might be an exercise in virtual reality, so that "we're in the matrix rather than the physics itself".

Is there any justification for believing this wacky idea? You bet, says Nick Bostrom, a philosopher at Oxford University, who even has a website devoted to the topic ( http://www.simulation-argument.com). "Because their computers are so powerful, they could run a great many simulations," he writes in The Philosophical Quarterly.

So if there exist civilisations with cosmic simulating ability, then the fake universes they create would rapidly proliferate to outnumber the real ones. After all, virtual reality is a lot cheaper than the real thing. So by simple statistics, a random observer like you or me is most probably a simulated being in a fake world. And viewed from inside the matrix, we could never tell the difference.

Or could we? John Barrow, a colleague of Martin Rees at Cambridge University, wonders whether the simulators would go to the trouble and expense of making the virtual reality foolproof. Perhaps if we look closely enough we might catch the scenery wobbling.

He even suggests that a glitch in our simulated cosmic history may have already been discovered, by John Webb at the University of NSW. Webb has analysed the light from distant quasars, and found that something funny happened about 6 billion years ago - a minute shift in the speed of light. Could this be the simulators taking their eye off the ball?

I have to confess to being partly responsible for this mischief. Last year I wrote an item for The New York Times, saying that once the multiverse genie was let out of the bottle, Matrix-like scenarios inexorably follow. My conclusion was that perhaps we should retain a healthy scepticism for the multiverse concept until this was sorted out. But far from being a dampener on the theory, it only served to boost enthusiasm for it.

Where will it all end? Badly, perhaps. Now the simulators know we are on to them, and the game is up, they may lose interest and decide to hit the delete button.

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