'The amount of computing you can do with one machine is increasing exponentially,' he said. 'In the next 15 to 20 years the increase in technology will be faster and faster until computers can process information as fast and then faster than the human brain.'

Mr Tan has already done his part to push forward the relentless march of technology.

As project manager for IBM's Deep Blue supercomputer, Mr Tan did what many thought impossible and built a machine that defeated grandmaster Garry Kasparov in a game of chess.

Some believe the 1997 match sent humanity a clear message that our days of intellectual supremacy were numbered.

'Deep Blue marked a turning point.

'For the first time it brought an awareness to the public about how far technology has gone,' Mr Tan said.

The processing power of computers doubles every 18 months, and industry analysts predict this meteoric rise will not slow down for at least another two decades.

High-powered supercomputers will soon be put to work folding protein and cracking DNA - work that would take hundreds of years to complete at processing speeds available now.

IBM is working on a US$100 million project to build a successor to Deep Blue called Blue Gene. It will be a petraflop computer capable of more than a quadrillion operations per second. That is 1,000 times more powerful than Deep Blue and about two million times more powerful than the latest PCs.

Deep Blue managed more than one teraflop - one trillion - operations per second when it dispatched Mr Kasparov on the chessboard.

United States inventor and technology visionary Ray Kurzweil estimates that a lizard's brain operates at about 10 teraflops, equal to the most powerful computers operating today.

In five years, he believes machines will hit 100 teraflops - or mouse-level brain operations.

Between 2010 and 2015, a team of scientists will create a computer that will reach 10,000 teraflops, equal to the operations of the human brain.

So what will it mean when, one morning, electricity runs through a mass of silicon and copper and something awakens that thinks faster than people?

In his book The Age of Spiritual Machines, Mr Kurzweil predicts people will become more integrated with their machines as we embark on a brave new era in which a person's brain can be mapped and their memories, skills and experiences loaded into an electronic computer brain.

Even if computers start thinking as fast as humans, the question remains as to whether they will make the final leap and become intelligent.

Mr Tan said until we fully understood how the brain worked, all the speculation was little more than science fiction.

'Right now we can mimic anything we can break down into mathematical processes, like playing chess.

'But we cannot quantify things like intuition, emotions and perception,' Mr Tan said.

But Mr Kurzweil said scientists would eventually learn how to use the tremendous processing power at their disposal to solve the mysteries of the brain.

He sees a time when we will have relationships with automated personalities and use them as teachers, companions and lovers.

Mr Kurzweil said before the middle of this century, thinking robots would run factories and farms, and planes, trains and cars would operate themselves.

But not everyone - even in the scientific world - is welcoming the thought of super-smart machines. Popular culture has inevitably portrayed intelligent computers as diabolical maniacs bent on destroying inferior humans.

Who can forget the demented Hal from 2001: A Space Odyssey?

Hugo de Garis, a Belgium-based scientist who has spent his career developing silicon brains, predicts his creations will lead to the end of the world as society disintegrates under the strain of dealing with the tremendous change supercomputers will bring.

'I believe that 21st-century technologies will allow the creation of artilects [ultra-intelligent machines], with intellectual capacities zillions of times greater than those of human beings,' Mr de Garis said.

'The question most thinking people will be asking themselves within a few decades will be: 'is humanity prepared to see its status as dominant species on our planet undermined by the artilects?' '

Mr de Garis said computers would destabilise the world to the point of causing a global war because people would constantly live with the fear of machines turning against them.

Other researchers dismiss those fears, saying we should not assume that intelligent machines will have human flaws or display emotions that will lead to conflict with people.

Mr Tan said he had moved on to find a different kind of conquest of machine over man.

'We don't need to play chess any more because we've already beat a grand master.

'May be someday I can build a computer that will play golf with Tiger Woods,' Mr Tan said.