HE Nobel prize in physics is usually bestowed for an abstract theoretical insight or esoteric experimental technique that deepens science's comprehension of the world. And physics being physics, it is often a challenge to explain to anyone but specialists just what the laureates are being honored for. Last year two Dutch physicists were recognized, in the Nobel committee's words, "for elucidating the quantum structure of electroweak interactions." The year before two Americans and a German bagged the prize "for their discovery of a new form of quantum fluid with fractionally charged excitations."
In contrast, this year's award, announced last week in Stockholm, seemed surprisingly down to earth. The three winners will share the prize for the invention of microelectronic chips and other components that lie at the heart of laptop computers, CD players, cell phones, fiber-optic transmission lines and other wonders of the digital age.
But the honor, especially when considered alongside the other big science prizes — for medicine or physiology and for chemistry — was striking in another way. There is no Nobel Prize for computer science. But obliquely and perhaps unconsciously, the judges were using the tools at their disposal to recognize how formidable the notion of information has become, pervading not just the technologies we devise but the way we think about ourselves.
While the physics prize went to three architects of the computer revolution, the chemistry prize went to the inventors of a technique for making plastic conduct electricity — a technology that might one day be used to design cheap, low-energy video displays that can be folded like sheets of stationery. And the physiology prize went to a trio of researchers who helped develop the modern view of the brain as a kind of computer, its neurons trading data as though they were biological chips.
The timing of the awards, each worth about $913,000, was probably coincidental, but the message was hard to miss: The notion of information has become indispensable for both manipulating and understanding nature.
Half the physics prize will go to Jack S. Kilby, a 76-year-old retired engineer for Texas Instruments, for his major role in inventing integrated circuits, in which millions of tiny transistors, trading streams of digital data, are now etched onto a single silicon computer chip. The other half of the money will be split by a Russian and an American physicist — Dr. Zhores I. Alferov and Dr. Herbert Kroemer — for devising tiny devices called semiconductor heterostructures, used in the high- speed processing of electronic and optical signals, blips of electricity and light.
The research that won the chemistry prize, given to two Americans and a Japanese, Dr. Alan J. Heeger, Dr. Alan G. MacDiarmid and Dr. Hideki Shirakawa, opens up numerous possibilities for data processing, including not just flexible video screens but powerful chips in which single molecules process bits of information.
All these inventions grew from the now commonplace realization that numbers, words, sounds and images — anything that can be described precisely — can be translated into a simple binary code of ones and zeroes and manipulated rapidly and almost flawlessly by machine.
But new technologies are just the beginning of the information revolution. The most intellectually fruitful development has been the cross-fertilization between computer science and neuroscience. Thinking of computers anthropomorphically has become second nature: A programming code is a language; an array of silicon chips is a memory. The prize for medicine or physiology, given to Dr. Arvid Carlsson, Dr. Paul Greengard and Dr. Eric Kandel, is a reminder that the commerce in ideas flows both ways.
The researchers, each in his own manner, have clarified how data circulate inside the brain. Molecules called neurotransmitters ferry signals from neuron to neuron, the information processors of the nervous system. There are obvious differences between electronic and biological circuitry. Computer chips communicate through simple metal wires. Neurons send their molecular data streams across complex junctions called synapses. And the language of the brain seems to be more complex than the simple binary chattering of computerese. But viewed at the most abstract level, both brains and computers operate the same way, by translating phenomena — sounds, images and so forth — into a code that can be stored and manipulated, giving both creature and their creations a firmer grip on the world.
Dr. Kandel has drawn an especially vivid link between the nervous system and electronic circuitry. In classic experiments he showed how learning causes changes in the neurological wiring of a sea slug called Aplysia, whose nervous system is so simple that experimenting with it is like tinkering with an old radio. Training the creature to react vigorously to a stimulus, like an annoying squirt of water, causes an increase in the flow of neurotransmitters — biochemical information — across certain synapses, a tweaking of the neurological volume controls. The implication is that more complex brain functions are built from millions of these kinds of processes, what Dr. Kandel has called "letters in the cellular alphabet of learning."
Next to the brain, the most obvious biological information processor is the genetic machinery of the cell. The design of an organism is encoded into the chemical alphabet of DNA and manipulated to direct the assembly of proteins. Again the trade in ideas flows in both directions: scientists have recently made DNA computers that carry out simple computations inside test tubes.
And in the physics labs, experimenters are playing with simple quantum computers in which individual atoms manipulate bits of data. True to form, some theorists argue that it's not only in captivity that matter behaves this way: All the quarks and electrons in the cosmic wilds are exchanging information each time they interact.
Alfred Nobel's prizes, paid for by the fortune he made from dynamite, began in an age when matter and energy seemed to explain nearly everything. (The first physics prize, in 1901, went to Wilhelm Conrad Roentgen for discovering X-rays.) Last week's prizes finally commemorated science's move into a new era, the information age.