Last Wednesday, 200 adventurers descended on Waterloo. Armed with pens and pads of paper, they came from all over the world to engage in fiery debate, actively trying to convince each other on subtle aspects of what the world is really like, and what it means.

Politicians? Poets? Business gurus? Metaphysicians? Not exactly. Last week marked the beginning of Quantum Information Processing 2004, a global conference to further development in quantum computing, quantum cryptography and other scientific initiatives to harness the remarkable capabilities of quantum theory.

Slightly over 20 years ago, the great American physicist Richard Feynman gave a landmark speculative seminar that, for many people, virtually launched the field of quantum computing. If, as many people maintained, all information is truly physical (that is, a fundamental reflection of the physical world around us), then it was definitely worth noting that the laws of nature are not, at their deepest core, those of Newton's classical mechanics, but rather those of quantum mechanics.

Electrons and protons (and more generally atoms), the building blocks of everything from tables and chairs to cellphones and computers, subscribe to a strikingly different set of physical laws than those of their larger collections (computers, tables and so forth).

Perhaps, then, it might be worth exploring what the physics of information really meant at this deeper level, in particular how the entire concept of quantum information might differ from its classical counterpart and how it might be harnessed. Feynman said it would definitely be worth exploring if one day physicists might be able to build a computer that was fundamentally modelled on the laws of quantum theory, rather than those of classical physics.

That day is already here. In laboratories across the world, experimental quantum information scientists are building baby quantum computers that can do a few simple tasks, while passionately debating which technology is best suited to move to the next level.

Meanwhile, mathematicians and theorists move relentlessly forward, pursuing a companion avenue. Unconcerned with how a quantum computer will actually be built, they concern themselves with chasing what can be done with it once it is built, and how it will differ from our current computers.

When the experimentalists get to the point where they develop quantum computers that are sufficiently powerful to be useful, the theorists will already have a remarkably good idea as to how we can use them.

Science fiction? Speculation? Perhaps. But consider this: every year, computers are getting faster at an alarming rate while the transistors on which they depend for their calculations increase in number and correspondingly shrink in size.

This celebrated march of technological progress, where the processing power of a microchip effectively doubles every 18 months, was first predicted in the 1970s by Intel co-founder Gordon Moore and is now simply known as Moore's Law

Of course, Moore's Law is not a law in the strict sense of being necessary (one could certainly imagine engineering advancement occurring at a considerably slower pace), but it has proven to be a remarkably accurate description of the pace of progress.

The problem is, however, that by 2020, if Moore's Law continues, transistors will be the size of atoms and dealing with the subtleties of the quantum world won't just be an interesting thought experiment -- it will be an absolute necessity for further progress. And even if Moore's Law doesn't hold, that day will definitely occur sometime in the relatively near future.

In short, the era of quantum technologies is coming. So 15 years from now, when you fire up your quantum computer, remember to spare a thought for the young, energetic physicists who are now walking through Waterloo. They will have made it all possible.