Brian Hayes

Perché la matematica dà sempre sorprese

Nelle prime righe di questo libro Hayes scrive "la matematica è troppo divertente per essere lasciata solo ai matematici". Aggiunge inoltre che lui non è un cittadino di Matelandia, ma una persona che si è trasferita lì e ha cercato di comprendere usi e costumi dei suoi cittadini. In effetti la sua formazione è più da informatico, tanto che negli anni '80 teneva la rubrica di Computer Recreations sullo Scientific American, mentre ora scrive su American Scientist. Lo troviamo così a dissezionare il famosissimo aneddoto di Gauss bimbetto e la somma della serie di numeri trovata al volo, tracciando le innumerevoli versioni per capire come il folklore matematico abbia man mano abbellito la storia; nel frattempo spiega come la differenza tra l'approccio del giovane Carl Frederick e quello di un programma al computer abbia ripercussioni importanti. Ma molte di queste meditazioni matematiche, pur non entrando a fondo nella teoria sottostante, sono davvero interessanti: segnalo quella sui numeri quasicasuali, sullo spettro del Riemannio (una correlazione a prima vista inimmaginabile tra gli zeri della zeta di Riemann e gli spettri degli elementi chimici), su un modo alternativo alla virgola mobile di memorizzare i numeri su un computer, che permette di aumentare l'ampiezza dei numeri rappresentabili conservando una estrema precisione nei valori prossimi allo zero, e soprattutto il gioco di Zenone. Una gioia per appassionati e semplici turisti!… (plus d'informations)

I found this book to be an exhaustive (and exhausting) compendium of things industrial. It focuses on the visible infrastructure of industry--pit mines, smokestacks, water towers, dams, power transmission lines--and explains what you are seeing in the landscape, and the overall process that necessitates the feature. If you've ever traveled cross country (particularly I-40 in the Southwest) and wondered about the random industrial things you've seen along the road, this guide can help decode the mystery.

I enjoyed learning a lot more about various mining practices and refinement of ores as well as other topics It was hard not being overwhelmed by the sheer scope of the book (probably a factor of not having much time to read it). Sometimes I wished there were more pictures or diagrams of processes described in the text.

It's a pretty massive book--wide rectangular pages, thick paper to accomodate the color photos. And the hardback library copy I was reading showed some serious spine damage. I would imagine the paperback version would suffer even worse.… (plus d'informations)

I have fond memories of watching episodes of Mr. Rogers when I was a kid and seeing the inner workings of things like crayon factories, one of my favorite elementary school field trips was to a local power plant, and my parents learned early on that one way to get me to stop tormenting my brother was to hand me picture books on construction equipment. If you're the kind of person who's interested in machinery, factories, power plants, and all the other aspects of the modern industrial substructure that are often hidden behind the commercial and residential façades of everyday life, then this is the book for you. Hayes went on countless trips over the course of a dozen years to photograph and describe places like strip mines, power plants, cement plants, water purification facilities, bridges, railroads, airports, shipping terminals, and much more, with an eye towards showing exactly what it takes to discover, extract, transport, refine, assemble, and deliver all the things that allow our societies to function. His basic philosophy on this stuff is summed up well in his Introduction, after a brief discussion of both the nature-is-best-unspoiled maximalist environmentalist and the Earth-is-our-dominion pro-development positions:

"My chief aim is simply to describe and explain the technological fabric of society, not to judge whether it is good or bad, beautiful or ugly. And yet I would not argue that technology is neutral or value-free. Quite the contrary: I submit that the signs of human presence are the only elements of the landscape that have any moral or aesthetic significance at all. In nature undisturbed, a desert is not better or worse than a forest or a glacier; there is simply no scale on which to rank such things unless it is a human scale of utility or beauty. Only when people intervene in nature is there any question of right or wrong, better or worse. When we look on a pristine glade, we are mere bystanders, but when we walk down a city street, we are responsible for what we see (and what we hear and small), and we are therefore called on to pass judgment."

For a much more thorough (and lyrical) discussion of questions about the morality of development and the inherent value, if any, of nature in its raw state, please see John McPhee's superb Encounters With the Archdruid. Meanwhile, this work begins with an exploration of the mining industry and doesn't stop probing the plumbing of the world for 500 pages. Hayes describes not only the names of important concepts (e.g. the difference between open-pit and open-cast mines), but how they fit in the industrial ecosystem, as well as important other elements such as the chemistry behind a particular process in a friendly yet rigorous way. For example, here he's talking about steel mills:

"The heated air is delivered through a fat duct that encircles the furnace about 20 feet above the base. This encircling duct is called a bustle, a name that has lost some of its descriptive power with changes in women's fashion. The pressurized hot air rises through the mix of ore and coke and limestone, igniting the coke and thereby raising the temperature even further.
Roughly speaking, the recipe for making iron is three cups of taconite to one cup of coke and half a cup of limestone. The chemistry that goes on when these ingredients are brought together is different from what happens in the smelting of copper. As described earlier, a copper smelter uses oxygen to lure sulfur away from the metal. But that can't work in the case of iron because the iron is already bound to oxygen. The oxygen is what needs to be removed, and it is carbon that acts as the seducer, carrying oxygen away in the form of gaseous carbon monoxide. Meanwhile, the limestone, the third ingredient, combines with other impurities to form a slag."

I also appreciate that he mentions political controversies, beyond the aforementioned basic environmentalist/developer one. A strip mine might be an impressive technological accomplishment, but it's also one of the worst things human beings can do to the planet. Hayes does not shy away from presenting the downsides to the upsides, or showing how things like levees both protect farmland and also engender perverse incentives to blow up your neighbor's levee to protect your own during a flood. He also occasionally dips into the more colorful sides of history; I wish there had been more info than he gave on exactly how this or that technological innovation progressed or came to be, but I appreciate that the book is already fairly long, plus he included a helpful list of further reading. Basically, Hayes nerds out blissfully about stuff like the evolution of the design of municipal water towers for the entire time, until he gracefully closes with an insightful Eloi-and-Morlock-ish analysis of how people relate, in our current era of automation, the "knowledge economy", and deindustrialization, to the "post-industrial" landscape of shuttered refineries, empty factories, and roboticized production lines:

"There is something of a paradox here. On the one hand, people today deal with machines on a much more frequent and intimate basis than earlier generations did. We pump our own gas; we get our cash from the ATM instead of a bank teller; we check our own groceries at the supermarket and our own books at the library; we make our own airline reservations over the Internet instead of consulting a travel agent. But most of us know less and less about how all these machines work. We know how to use them, but not how to build or fix them. As for the more remote machinery - the turbines, pumps, generators, transformers, switches, amplifiers, transmitters, and all the rest of the apparatus that keeps an industrial economy humming - all that is quite out of sight....
There is something sad about a society in which large numbers of people don't understand the substrate of their own world. In the case of the natural world, everyone ought to have at least a rudimentary grasp of the laws of physics and those of biology, such as Darwin's principle of evolution by natural selection. Without a sense of how materials and energy flow through an industrial economy, you miss something basic about the world you live in....
Sooner or later, decisions about the direction of important technologies have to be made by a democratic process. People who have never seen a power plant, who know nothing of how it works, who have never met anyone who works there, are poorly equipped to judge the relative merits of nuclear and coal-fired technologies, or to seek alternatives that might allow us to dispense with both. To make good decisions about such issues, citizens need to get better acquainted with the technological underpinnings of their own communities."

It's hard to argue with that, and it would be hard to find a more beginner-friendly way to get acquainted than this well-written, enthusiastic, and informative guide.… (plus d'informations)