Chaos theory takes a leap

GOD MIGHT not play dice, but he seems to enjoy messing around with mathematicians. Centuries after they thought they had wrapped up the science of prediction with the bell-shaped curve - which forecasts the likelihood of random events - they have discovered that the universe has another law up its cosmic sleeve.

This law applies to a huge class of events, including the weather and natural disasters such as earthquakes, floods and forest fires. Although statisticians use the bell-shaped curve to forecast the likelihood and severity of such events, the new curve is likely to supplant it.

That could have a significant effect on insurance premiums and disaster prevention, because the curve suggests that "rare" events - such as, say, a very powerful hurricane - will occur more frequently than the bell-shaped curve predicts.

The new curve, which does not have a name, was discovered independently by researchers into magnetism, ecosystems and fluid turbulence. That implies that it is universal among particular systems defined mathematically as both "chaotic" and "self-similar" - that is, their behaviour has the same form whether viewed close-up or from a distance.

Dr Steve Bramwell, a chemist at University College London who discovered the curve while studying metals' magnetic properties, said yesterday: "This is a breakthrough in bringing these systems into the mainstream of physics."

Now, scientists are seeking the curve's mathematical formula. The bell curve predicts in a random sample of independent events how often one will happen. The new curve, however, applies to a random sample in which the events are not independent, because chaotic systems have an interplay between their elements: famously, the weather is unpredictable to the extent that the flap of a butterfly's wing can mean the difference between sunshine or a hurricane in the future.