IN THE summer of 1942, the second world war was raging in the Pacific, with no sign of progress for the Allies. A single feature of one radio transmission was to change that. When the Japanese used the code “AF” in a message, referring to Midway Island, US cryptographers at Pearl Harbor identified it as the target of an impending Japanese attack. The subsequent US defeat of the Japanese fleet turned the tide – and showed how information can literally “in form” or “give form to” the larger flow of events.
In Decoding the Universe, Charles Seife builds on this dramatic example to prove that while information science sounds like a topic for geeks, it may be the most fundamental of all sciences, in that the laws of information are so close to the deep laws of nature, or at least provide the logical fabric from which they flow.
This big idea has garnered wide attention. Biologists increasingly view the cell as a unit shaped by evolutionary processes for effective information processing, while physicists suspect that the laws of quantum physics may ultimately derive from some deeper laws of information. This is a timely book, and Seife does an excellent job with an undeniably difficult topic.
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So what is information? Anthropologist Gregory Bateson had a notable attempt to define it: “Information is any difference that makes a difference.” Put another way, it is any feature – in a string of symbols, or the markings on a human face – that stands out and can carry meaning.
Seife’s starts with the origins of “information theory”, brainchild of mathematician and engineer Claude Shannon. Emerging after the second world war, Shannon’s work set the foundations for communication theory, which measures the information in any signal. What he didn’t realise was how his concept would help resolve many thorny issues.
Take Maxwell’s “demon”. In 1867, Maxwell thought he had found a loophole in the second law of thermodynamics, which demands that entropy – a measure of the disorder in a system – should never decrease in any physical process. Maxwell imagined a tiny demon sitting in a box of air and sorting warmer and colder molecules from each other, then pushing them to different sides of the box, thereby lowering the entropy and violating the second law.
It took over a century, but in 1982 physicist Charles Bennett, building on Rolf Landaur’s work, showed that the demon has to process and store information in sorting the molecules, and must inevitably destroy information when he runs out of storage. This “destroying” process is irreversible and creates enough entropy that the net entropy increases.
This is a fine illustration of Seife’s theme: that the perspective of information can help explain what is otherwise puzzling in everything from quantum theory to molecular genetics. One such fundamental puzzle still to be resolved is why the smallest things, such as atoms and the like, can coexist in two or more states simultaneously (quantum superpositions), while big things like swimming pools or the moon seem to exist in definite states.
This is quantum theory’s famous “measurement problem”. Seife argues, and most physicists would agree, that information will be key to any answer because it provides a mechanism whereby superpositions of large objects inevitably get tangled up with their environment, and, for all practical purposes, washed away.
One extremely minor criticism is that Seife might have explored the role of information in the social arena, in the economics of “information asymmetries”. Why, for example, does the price of a new car plummet as it is driven off the lot? These oddities also find their origins in information, especially in the imbalances in the information people hold.
Also, the fairly wild subtitle (“How the new science of information is explaining everything in the cosmos, from our brains to black holes”) should have been axed. The book doesn’t need hype. Decoding the Universe is an admirable effort to bring to life a subject that is often written about in dreadfully dry terms. Seife makes a clear case that information runs deep, akin to logic and pure mathematics, and the laws that constrain the possibilities of our world.
Decoding the Universe
Viking
