Nobel prize winners for science named

THE INVENTOR of the modern-day version of the 'cloud chamber' - one of the more fun experiments in school physics laboratories - has won this year's Nobel prize for physics.

The chemistry prize has gone to a Canadian-born scientist, Rudolph Marcus, 69, of the California Institute of Technology, for theoretical work on how electrons might hop from one molecule to another. Each prize is worth 6.5m Swedish kronor ( pounds 1.2m).

When Georges Charpak, 68, learnt he had won the physics prize, he said: 'Great, then I can buy a new pair of shoes this afternoon.'

The Royal Swedish Academy of Sciences cited Dr Charpak, a Polish-born Frenchman who has worked at Cern, the European Laboratory for Particle Physics, near Geneva, in Switzerland, for the past three decades, 'for his invention and development of particle detectors, in particular the multi-wire proportional chamber'.

Wire chambers are at the heart of all detectors used today to sift through the subnuclear debris produced in collisions at atom- smashing accelerator laboratories. Children are still taught the use of old-fashioned 'cloud chambers' to detect subnuclear particles. Thanks to Dr Charpak, these and the more sophisticated 'bubble chambers', which were used in particle physics experiments in the 1960s and early 1970s, have become redundant.

Cern has found a use for some of its old bubble chambers - as ornamental aquaria.

Dr Charpak's award falls into a consistent tradition. The inventor of the cloud chamber, C T R Wilson, and of the bubble chamber, D A Glaser, received Nobel prizes in 1927 and 1960 respectively for their inventions.

The key to Dr Charpak's invention is that wire chambers use electronics and can be connected directly to computers, for direct on-line readout and analysis of what has been produced in a subnuclear collision. This enables scientists to choose which reactions to analyse out of the hundreds of thousands taking place. 'Sometimes only one particle interaction in a billion is the one searched for,' the academy said.

Professor Rudolph Marcus developed his theories on electron transfer during the late 1950s and early 1960s, yet it took a further two decades until chemists were able to confirm his predictions experimentally. Electron transport underlies such disparate phenomena as photosynthesis - the ability of green plants to harness light energy - corrosion, and chemiluminesence or 'cold light'.

Professor Marcus realised that the rate at which such electron transfers could proceed depended not just on the two molecules but on the others in their immediate vicinity. In certain circumstances, his calculations predicted profoundly counter-intuitive results - the harder the driving force behind the reaction, the more slowly it would proceed.

(Photograph omitted)