_Midway through Mapping The Next Millennium: The Discovery of New Geographies (Random House, $30.00, cloth) Stephen S. Hall visits a pair of Russian emigre brothers, Gregory and David Chudnovsky, who live in an eighth-floor apartment on the Upper West Side of Manhattan. Their room, he says, looks “like a makeshift and disheveled electronic brain that has burst out of its architectural housing and spilled into what once must have been a living room, its memory and its synapses cobbled together from four or five monitors, a few central processing units, data storage packs, cables crisscrossing the parquet floor, and of course the telephone lines, metallic axons of modern computer networks, linking this monastic cell and its nimble-minded homebodies with the most powerful computing machines in the world, which the Chudnovskys use to explore the imaginary terrain of pure numbers.” None purer than pi, which the Chudnovsys figured out a new way to calculate to more places than anyone who had gone before them. To perform the calculations, they needed to borrow computer time from labs and research centers around the country—fifteen minutes here, an hour there. They had to “beg for invaluable electronic warehouse space in which to store their millions of digits.” They had to cope with numerous crashes, where millions of those digits simply disappeared. It was, one of the brothers told Hall, like “doing mathematics at a laundromat—the next day you come and maybe you find what you left.” They persevered, however, and by September of 1989 they had computed pi to 1,011,196,691 digits. At the moment, they’re planning to calculate an additional nine billion digits that may help them see some pattern.

The Chudnovskys are typical characters in Hall’s book—marvelously vivid, reasonably comprehensible, somewhat socially awkward, and full of fascinating information from the frontiers of the their particular field. Hall chose his topic well—his hunt for the explorers who are making this century’s “maps” allows him to rove broadly through the laboratory corridors, knocking on almost any door. Some are analyzing the data that Voyager 2 sends back from the edges of the solar system, while others are using gravitational anomalies to figure out the geography of the sea bottom, or studying seismic waves to chart the layers of the earth’s core. He interviews the CAT scanners and magnetic resonance imagers who are taking the sharpest pictures of human innards, and the neurologists figuring out which continents in the brain are on speaking terms with each other. The mappers of the human genome are included, of course, and those building new microscopes that can see atoms, and the pioneers of chaos (Hall’s book owes a certain debt of inspiration, I would guess, to Jim Gleick’s masterful Chaos), and the egomaniacal subatomic heroes fighting for federal funds to build ever-faster supercolliders and find ever-smaller particles. From the small he heads fearlessly for the big—to the astronomers’ mapping of the Milky Way and the Great Attractor and the Great Wall and the other somewhat enormous phenomena that either prove or don’t prove that it all started with a Big Bang.

Hall, who has written for Omni and Smithsonian makes sure the academic never crowds out the anecdotal—if I really cared about how precisely to map pi to a billion places, or if there was any possibility I would understand, then this might be a drawback. But almost every reader will prefer the locker-room interviews he provides, where scientists condense the impossibly complex to the equivalent of “he was throwing a mean curve tonight.” Some of his subjects turn philosophical (the astronomer John Huchra says, “The two most important sentences to learn in the English language are ‘I don’t know’ and ‘I am wrong.’ If you learn to speak those words without trepidation, life will be much easier”). Others tell jokes—his ocean-floor geographer, for instance, has a sign on the door that says: “Gravity. It Isn’t Just A Good Idea. It’s the Law.” A few hours of pleasant reading and you have a pretty good map yourself: A guide to the envelopes that scientists are currently pushing, the boundaries between knowledge and ignorance they are currently busting through. The command with which he moves from subject to subject proves he’s done his homework; he rarely goes too deep, he never skims too high above the surface. All in all, a long and engrossing magazine article.

At the beginning and the end of his book, however, Hall goes beyond reportage to philosophizing. And while his philosophizing is not very good, without knowing it he does manage to bring up what seems to me the great problem of science in this day. Hall thinks that the problem is that scientific advance may allow us to act irresponsibly. Clearly exploration usually proceeds exploitation—that is true to the point of being a cliche. But while he is right to warn that the human genome map might chart the way towards eugenics, and perhaps even to fear wars over the mineral resources of Venusian moons, he misses what I think is a greater danger, a danger linked squarely to his notion of maps. That danger, fostered in this book, is the belief that all the frontiers of science are equally relevant and important.

In the old days, he says, the editors of the eleventh edition of the Britannica defined a map as a “representation, on a plane and a reduced scale, of part or the whole of the earth’s surface.” This “narrow land-based” definition of a map, he says with enthusiasm, has now been endlessly multiplied by the new territories scientists have found: “chromosomes, zygotes, atomic surfaces, star-forming regions in the Milky Way, the large-scale galactic structures of the universe.” But are most of these new realms really of equivalent importance with the “narrow, land-based” kingdoms of the old mapmakers? I think not. The stubborn fact is, for nearly all people in nearly all situations nearly all the time, the world still exists on a terrestrial scale. Though we have chromosomes, we do not experience the world on the chromosomal scale; though a few of us with very high-powered instruments can map superclusters of galaxies, those superclusters have very little to do with how we perceive the world. And very little to do with how we need to perceive the world. Which is not to say we shouldn’t study them. Merely that they should not distract us from understanding and caring about what is immediately around us—the natural world as it is perceived by our eyes and ears and other unaided senses.

The temptation of much of modern science—and much of modern science writing—is to ignore the obvious, three-dimensional, apparent-to-the-naked-eye nature in favor of nature’s more exotic manifestations. In large part, this is because we think we understand a good deal of what is around us— in mapmaking terms, certainly, we have now charted the coastlines of our terrestrial continents. It seems static, almost dull. And yet it is precisely in this dimension that nearly all the action takes place. The great questions of our day are environmental—the greenhouse effect, in particular, threatens to change almost every facet of the easily observable world. Even now, however, it is hard to get the money to study it, hard to attract the best scientists, and hard to get across to people that it matters. Matters far more than, say, the structure of the universe. That will be there, unchanged, to study in a hundred years or a thousand years or a million years. The same for the details of atomic construction. But in a hundred years the earth itself—its continental outlines, its vegetation, its roster of species, its food-producing ability—may have changed more quickly than ever in its past.

Hall does devote a chapter to climate mapping, but it is a strange chapter, the weakest in the book. (I should say that in it he also pokes fun in passing at the title of a book of mine.) He mentions the climate map of James Hansen of NASA exactly twice, only to say that its conclusions are unproven (a criticism that could be leveled against nearly every other scientist in the book). But these elaborate computer models of the global climate successfully predicted that the 1980s would be the warmest decade on record, and in fact gave Hansen the confidence to predict that either 1990, 1991, or 1992 would be the warmest years we know about, a bet he won in 1990. His model, presumably, is far from perfect. But it has served as the basis for most of the important public predictions about global warming, which even skeptics agree would, if it happens, produce changes that might threaten nearly every human and animal endeavor. They are probably the most important charts anyone anywhere is currently making, and that Hall gives them short shrift proves that, for all his reporting ability, he does not understand that scale is the most important parameter on any map. The scale at which we live may well be under siege—that is the breaking story of “the next millennium.”