SCIENCE: LAB NOTES

Bi-weekly news from the world of science

Dangerous currency

When 11 member nations of the European Union moved to adopt the euro as their single currency last May, computer managers everywhere issued a collective groan. They now must refit every financial system that handles data tabulated in the traditional Continental currencies. Moreover, they need to be ready in just a few months, by January 1999, when the phase-in to the euro begins. Some experts worry that this software crisis could rival the notorious "millennium bug".

The European Commission in Brussels has also published strict rules for financial computers. Converting between currencies could soon require "triangulation", so that francs are first converted to euros, and then into marks. Some software will have to display both the local currency and the euro during the transitional period (1999 to 2002).

Faced with these bugs, "a lot of companies in Europe will find themselves in dire straits," says Achi Racov, chief information officer of the London-based NatWest Group. He expects his firm will spend in excess of pounds 200m to handle the euro and the millennium-dating problems. All told, the cost of modifying systems in Europe is expected to run between pounds 90bn and pounds 250bn.

Mars awash!

Proof continues to accumulate that the Red Planet was once a much wetter, warmer place than the barren, freezing world visited by recent probes. Philip Christensen of Arizona State University has analysed data collected by the Mars Global Surveyor, a spacecraft that has orbited Mars for several months. In measurements taken by an instrument called a thermal emission spectrometer (TES), he found signs that the planet's surface contains deposits of coarse-grained hematite, a mineral formed in bodies of water or at sites where there are high levels of thermal activity.

Geologists hope to mount a more direct examination of the hematite deposit, which measures some 300 miles in diameter, when a new mission that includes a lander heads to Mars in 2001.

Brainstorm

Epileptic seizures are often described as a storm of chaotic electrical activity that grips the brain. But new research suggests that epilepsy may actually involve too little chaos.

Klaus Lehnertz and Christian Elger of the University of Bonn collected 68 electroencephalograms (readings of electrical brain activity), then estimated normal levels of electrical fluctuation in terms of "dimension" - a mathematical property in chaos theory that describes the complexity of the observed pattern.

They observed that approximately 11 minutes before the onset of a seizure, the part of the brain where seizures usually begin loses a level of complexity. Investigators have previously hypothesised that low levels of chaos in organs that perform regular tasks, such as the heart, may help make those organs more reliable; their tiny fluctuating errors make their overall behaviour more robust. Perfectly timed systems, in contrast, can be permanently desynchronised by even small perturbations. Therefore, loss of chaos in part of the brain may leave those cells vulnerable to huge swings in disorganized activity, such as are seen in epilepsy.

! All items are adapted from `Scientific American' magazine. Copyright 1998, Scientific American, Inc. Visit the `SA' website at www.sciam.com. All rights reserved