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When computers take overWhat if the current exponential increase in information-processing power could continue unabated?

The Singularity is Near: When HumansTranscend Biologyby Ray KurzweilViking/Duckworth: 2005. 672 pp.$29.95/£14.99

Paul DaviesI recall reading a statistic from my student daysto the effect that if physics journals continuedto grow at the same rate, then by the end of thetwentieth century, library bookshelves wouldhave to expand at the speed of light to accom-modate them. This absurdity is an illustrationof what one might call the exponential-growthfallacy. Examples drawn from technology arelegion. The Moon landing in 1969 was widelytouted as the first small step on an escalator tothe stars, with Arthur C. Clarke predictinghuge lunar bases and a Jupiter expedition by2001. The rapid uptake of robotics in the man-ufacturing industry after the Second WorldWar led to predictions of cyborg servants andandroid armies within a few decades. In theevent, these technologies became stuck oreven slid backwards.

The key point about exponential growth isthat it never lasts. The conditions for runawayexpansion are always peculiar and temporary(with the possible exception of the expandingUniverse). But this sobering fact has notstopped futurologist and author Ray Kurzweilfrom invoking exponential, and even hyper-exponential, growth in the realm of infor-mation processing. There is no doubt that therise and rise in computing power has dazzledus all. Gordon Moore, co-founder of Intel,famously predicted about 30 years ago thatcomputer processing power would doubleevery 18 months, and so far his prediction hascome true. Kurzweil invokes ‘Moore’s law’ as ifit were a law of nature, and extrapolates from itinto a not-so-distant future in which burgeon-ing information processing transforms andtranscends life as we know it. He refers to hisculmination point, at which familiar humanculture is obliterated by a tidal wave of unre-strained computation, as the ‘singularity’. Theword is loosely analogous to the mathemati-cian’s singularity, at which the rate of change ofa quantity becomes infinite.

If the sky’s the limit when it comes to pro-cessing information, it isn’t hard to think ofstartling applications. Tired of deciding whatto eat? Let a swarm of sensors patrol your

innards and order the right nutrients automat-ically through your personal wireless network.Concerned about dying? Then achieveimmortality by flooding your body with smartnanobots to monitor and maintain your failingbiosystems. Or better yet, ‘upload’ your mindinto cyberspace, where you can have more fun,untrammelled by a material body.

The question is not whether these wild ideasshould be taken seriously, but whether thepremise on which they are founded —unbounded exponential growth in informa-tion-processing power — somehow escapes thestrictures that eventually curtail all other casesof headlong expansion. One obvious reasonwhy accelerating growth in computation mightstall concerns the availability of resources. Whathappens when the Earth’s entire surface hasbeen converted into a gigantic information-garnering, bit-churning system? Kurzweil isready with the answer: we move into space.(“We” here is a generic term. The sentientbeings that will soon wrest control fromhumans, and which are destined to supervisethe cosmic phase of development, will be somesort of superdupercomputers.) But by theremorseless logic of exponentiation, pretty soonthereafter the resource-hungry system will finditself spreading across the galaxy so fast it hitsthe speed of light. Like the physics journals on

the bookshelves, exponential growth stops here.Or does it? Kurzweil toys with the idea that thespeed-of-light barrier is there to be broken,which opens up the giddy prospect of the entireUniverse being taken over by an omniscientsuperintelligence within just a few centuries.

Such exhilarating speculation is great fun toread, but needs to be taken with a huge dose ofsalt. The biggest lacuna in Kurzweil’s argumentis the tacit assumption that if we liberateenough information-processing power, thennature will succumb to all our desires. Controlthe Solar System? Just double the bit rate a fewtimes and it will be within our grasp. Createlife? Simulate consciousness? It all boils downto making a cheaper, faster processor. Unfor-tunately, the laws of physics may well dictateotherwise. Technology can harness physicallaws but it can’t bend them. No amount ofinformation processing will suspend the law ofgravity or create perpetual-motion machines.

When it comes to discussing the physicsthat underpins his predictions, Kurzweil is aptto be vague or even misinformed. The stupen-dous power demands implied by the rampantgrowth in computation and nanotechnologywill be met by a concomitant ‘law of accelerat-ing returns’ in power-generation technologies,such as fuel cells and high-temperature super-conductors. And if these run into technical

A giant leap: will increased computing power allow machines to take over, as in films like The Matrix?

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problems, well, just send in the nanobots to sortthem out. “All technologies,” claims Kurzweil,“will essentially become information technol-ogies, including energy.”

On the vexed issue of the speed of light,Kurzweil cites evidence that the fine-structureconstant, which expresses the strength of theelectromagnetic force and contains the speedof light as a factor, may have increased veryslightly over the past 6 billion years. The pri-mary evidence comes from an analysis ofquasar spectral lines by John Webb of the Uni-versity of New South Wales in Australia andhis collaborators, not from a study of the Oklonatural nuclear reactor in Gabon, as Kurzweilstates. Furthermore, even if the observationsopened the way to manipulating the value ofthe fine-structure constant, that is not the sameas increasing the speed of light and leaving

everything else unchanged. Indeed, the manip-ulation would involve a reduction of the fine-structure constant, which would slow the rateof information processing at the atomic level,and so prove self-defeating.

These technical hiccups are irritating, but the book should not be read as a scientific treatise. Rather, it is a futuristic and somewhatbreathless romp across the outer reaches oftechnological possibility, limited only byhuman imagination. Kurzweil coins the horri-ble term ‘singularitarian’ for someone whoembraces his vision with alacrity. If Kurzweil is to be believed, we will all be singularitarians in just 29 years’ time. Hang in there. ■

Paul Davies is at the Australian Centre forAstrobiology, Macquarie University, Sydney, New South Wales 2109, Australia. His latest bookis How to Build a Time Machine.

weary way to the butchers, and thence to din-ner tables. Many would have been especiallyweary, having been driven hundreds of miles tourban markets. If they couldn’t make it undertheir own steam, they were not permitted to besold. Those that could walk the last mile wouldbe inspected, slaughtered and consumedquickly. The idea of allowing meat to age afterslaughter is a recent luxury. So is the tendencyto eat younger animals, rather than those pasttheir capacity to provide milk or wool.

Ferrières also considers other foodstuffs,notably fruit, vegetables and grain. Theseinvoked their own fears, especially unripe fruitand mouldy bread, but most legislationrevolved around meat, which was a centralpart of diets half-a-millennium ago. Economiccircumstance determined whether one atetripe or rotten meat with one’s bread, notwhether vegetable stew was the main dish. The

poor were often given, or sold cheaply, animalsdeemed unfit for commercial consumption.

Social fears often generate fantasies of agolden age, when football hooliganism wasunknown, crime was low, nuclear familiesfeasted on wholesome food, and everyone goton well with their neighbours. There is none of that in this volume: the poor struggled, atebadly and died young. Ferrières argues con-vincingly, I think, that the nineteenth centurycreated the modern food dilemma. Canning,transportation and, eventually, refrigerationextended the food chain. People who wouldtraditionally have seen, touched and smelledthe food they were buying now needed only toread the labels. Instead of trusting themselves,they had to trust others. Food inspectiondeclined as political and economic liberalismgrew. At the same time, more widespreadaffluence put a premium on taste, often at theexpense of safety. Miasmatic theories of dis-ease and bourgeois sensibilities ensured thatthe slaughtering was done outside the city centres. Animals no longer had to be able towalk to their destinies.

Ferrières concentrates primarily on France,although there are insights into other culturalexperiences, including the persisting Britishpolicy of stamping out disease using wholesaleslaughter, which is a clumsy tool of diseasecontrol. She has a fine sense of the dramatic,faithfully conveyed in the translation, which issometimes literal at the expense of easy flu-ency. Away from France, some of the detailsbecome fuzzy: a London suburb appears asIssington, rather than Islington, and GeorgeBarker has transmuted into someone calledThomas Halwek.

This book is not for the squeamish, but thoseinterested in the culture of the table, or the historical intersections of health, taste and diet, will find plenty here to satisfy their appetites. ■

W. F. Bynum is at the Wellcome Trust Centre forthe History of Medicine, University CollegeLondon, London NW1 2BE, UK.

A taste of a rotten pastSacred Cow, Mad Cow: A History of Food Fearsby Madeleine FerrièresColumbia University Press: 2005. 416 pp.$29.50

W. F. BynumAmong the formidable list of modern anxi-eties, those related to food safety loom large.Mad cow disease, genetically modified crops,factory farming, residual pesticides, additives— we read about them daily and are remindedof them when we shop by labels assuring usthat we don’t need to worry when buying thisparticular product. We are, after all, what weeat; or more to the point, we are defined bywhat we do not eat.

All these contemporary concerns giveMadeleine Ferrières’ monograph a powerfultopicality. To her credit, she never panders tothe worried well, but sticks to a rich and well-exploited range of historical sources: advicemanuals, legal records, statutes, court cases,medical textbooks and imaginative literature.Her running theme is boldly stated: food fearsare perennial, although they take differentforms depending on the cultural milieu. Butthe subsidiary theme is also amply demon-strated: fear about food quality varies inverselywith fear about food quantity, both temporallyand through social strata. If your belly isempty, you don’t worry too much about addi-tives or saturated fatty acids.

The title of the original French edition high-lights the book’s chronological coverage, whichranges from the Middle Ages to the beginningof the twentieth century. So there is nothingabout mad cow disease here, despite the allu-sion in the title of the English version. Instead,in earlier generations, domestic animals withtuberculosis, trichinosis, foot-and-mouth dis-ease and a variety of other ailments made their Food to die for? Good food was available to previous generations, but not all of it reached this standard.

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