01 April 1998

Lateral thoughts both large and small

It is Babbage’s view that any fact might ultimately be useful, whether it be the heart rate of a pig, the proportion of sexes amongst poultry, or the tabulated causes of breakage of plate glass windows. Trivia, some may think. But a wealth of random knowledge is the basis for serendipity - chance associations that lead to fruitful discoveries - and Babbage was recently musing on the nature of such happy accidents in relation to the Analytical Engine.

The problem-solving power of chance association, whether called "intuition" or "lateral thinking", has been a vital ingredient in our evolutionary success. Its value has been immortalised in mythology, from Herakles’ idea of diverting a river to clean the Augean stables, to the tales of Archimedes’ bath-time “Eureka!” and Isaac Newton’s apple. It is a prime example of a role where the human brain bests the Analytical Engine; yet logically it seems an area in which the Engine could supersede us in seeking unsuspected correlations between facts.

In theory, this needs three components: huge data stores; repeated trial-and-error associations between items; and rapid probability-based assessment of the worth of any trial. These, however, give contradictory requirements of size and speed. For conventional chips, the Moore’s Law model - an annual doubling of manufacturable circuit density - is already running into physical constraints. To achieve the necessary performance, the options are larger devices, or new miniaturisation techniques.

A truly colossal device is already with us: the Internet. But what is waiting to be born is a vast distributed Analytical Engine whose parts spontaneously compare and process data among themselves, just as social animals (humans included) share knowledge and decision-making across their group. Babbage dubs this “metamachine” the Gaia Engine, in whimsical homage to Mr James Lovelock.

At the other extreme, we see the portents of engineering on the microscopic scale of animal nervous systems: for instance, the neurology of the locust’s flight control is well understood as a servomechanism; and Israeli scientists have produced short lengths of silver-plated DNA wire. Who can doubt that logic gates, then large scale integration - the ‘biochips’ of Mr William Gibson’s novels - will follow?

With such developments combined, Babbage's informants predict, we may soon see the day when the Gaia Engine will stir, try out a hunch and intuition or two, then settle down to some truly serendipitous lateral thinking.