Informed choices
Oct 12th 2000
From The Economist print edition

This year’s Nobel prizewinners have all benefited mankind. But they have had to wait a while for their invitations to Stockholm

IN ASPIRANT Nobel laureates, patience is undoubtedly a virtue. The passage in Alfred Nobel’s will which sets up the prizes refers to "those who, during the preceding year, shall have conferred the greatest benefit to mankind". This clause, presumably intended to inspire a sense of urgency, is honoured more frequently in the breach than in the observance. There is no question of the benefit conferred by this year’s winners. Few men, for example, have had a greater impact on the second half of the 20th century than Jack Kilby, one of three winners of the prize for physics. Dr Kilby invented the integrated circuit—the basis of the zillions of silicon chips found around the world in devices as diverse as computers and dishwashers. He did it, however, in 1958. Never say the Swedish Royal Academy of Sciences is not lengthy in its deliberations.

Dr Kilby shares his prize with two other undoubted benefactors of mankind, who also did their pioneering work four decades ago. Between them (though working independently) Zhores Alferov, in the Soviet Union, and Herbert Kroemer, in the United States, realised that interleaved layers of gallium and arsenic could semiconduct in the same way as silicon—and would, in addition, have the useful property of emitting light. Lasers working on this principle have become the basis of modern telecommunications, since they are used to generate the signals that are sent through fibre-optic cables. They are also used to read both CDs and the bar-codes without which it now seems impossible to make any purchase in a high-street shop.

The winners of the chemistry prize are, by comparison, mere striplings. Alan Heeger and Alan MacDiarmid, both Americans, and Hideki Shirakawa, a Japanese, did their prize-winning work at the end of the 1970s, also in the field of exotic electrical materials. The three were responsible for the development of the first electrically conductive plastics—a counter-intuitive idea, since until their work such polymers had been regarded purely as insulators. But Dr Heeger, Dr MacDiarmid and Dr Shirakawa found that certain so-called conjugated polymers (in which the carbon atoms forming the chain at the heart of the polymer are linked together by bonds whose component electrons are more than usually mobile) could, indeed, be induced to carry a current.

In this case the academy’s caution might be justified, since conductive polymers are only now starting to come into their own industrially. Over the next few years, though, they are likely to become important, particularly in a new generation of flexible display screens. Recent work has also demonstrated that at suitably low temperatures they can act as superconductors—transmitting an electric current indefinitely, without power loss.

The medicine prize is awarded not by the academy, but by the Karolinska Institute, Sweden’s leading medical university. But this organisation, too, clearly favours the long view. At the same time that Dr Kilby was demonstrating the first integrated circuit to his colleagues at Texas Instruments, Arvid Carlsson, a Swede, was carrying out the experiments that have won him a share in this year’s medicine prize. These were into the role of a chemical called dopamine in the transmission of signals across the synapses between nerve cells in the brain. He demonstrated that dopamine is, indeed, such a neurotransmitter; and he showed that it (or rather a lack of it) is involved in Parkinson’s disease. This paved the way for the treatment of Parkinson’s with a drug called L-dopa, a chemical precursor to dopamine.

This work was followed up by the second medicine laureate, Paul Greengard, another American, who showed how dopamine and several other neurotransmitters actually work. They do so by starting chain-reactions that result in the addition and subtraction of molecular sub-units known as phosphate groups from particular proteins in the nerve cell being stimulated. These changes alter a cell’s ability to conduct electrical signals, and thus to transmit messages along their lengths.

The third medicine laureate, Eric Kandel, is also an American, although of Austrian birth. He carried the baton a bit farther by looking at the biochemical changes involved in the formation of memory—first (because such experiments are unethical in people) in sea slugs, and then in mice.

Short-term memory, he discovered, relies on the phosphorylation mechanism described by Dr Greengard. He then went on to study permanent memories. These, he found, require the manufacture of proteins, and the rebuilding of synapses. But although the resulting circuits work on rather different principles from those invented by Dr Kilby, there is a sense in which all of this year’s winners are linked by the theme of information-processing. As the Nobel prizes enter their second century, their guardians have paid a fitting tribute to the first.