Book Review: 'Stuff Matters' by Mark Miodownik Substantial Achievements

Book Review: 'Stuff Matters' by Mark Miodownik Substantial Achievements

 The almost-magical properties of glass, chocolate, steel and other everyday materials.

By Peter Pesic in the Wall Street Journal

A teacup, a concrete wall, some chocolate, a glass, some stainless steel—ordinary objects, familiar and ubiquitous. Now they have found their poet in Mark Miodownik, a scientist at the University of London who, in "Stuff Matters," gives a thrilling account of the modern material world. In 10 chapters he successively takes up the humdrum artifacts found in a photo of himself sipping tea on his London rooftop to investigate the secrets of their physical properties.

Mr. Miodownik's fascination with materials science began when, as a teenager, he was slashed across the back by a mugger on the Tube. Marveling that an ordinary razor had sliced through his leather jacket and four more layers of clothing besides, he became obsessed with steel's uncanny edge. No less sharp is his account of the science behind the blade. He takes us to the atomic realm to see that steel is made of tiny crystals, the atoms of iron and carbon aligned in regular geometric patterns. The specific properties of different steels, however, depend also on the dislocations within its structure—the defects and deviations from perfect crystalline order. How easily those dislocations move determines whether the metal will bend—like a paper clip—or snap. Throughout, Mr. Miodownik interweaves scientific insights with historical nuggets—such as Romans burying tons of valuable nails, lest they fall into barbarian hands, and the nature of the fabled "jewel steel" used to make samurai swords, a layered combination, it turns out, of soft low-carbon steel for flexibility and high-carbon steel for edge.

Indeed, historical traces surround even what seems a quintessentially modern building material, concrete. The Roman Empire was built on concrete, including what is still the largest free-standing concrete dome in their Pantheon, which I've admired without realizing what it was made of. After the Romans, the secret of making concrete was lost for a millennium, perhaps because it involves a subtle intermixture of materials; the Romans had been lucky enough to discover a kind of natural cement (the crucial binding agent in concrete) in volcanic sands outside Naples.

Now over half of all construction is concrete, often reinforced with steel, to which concrete miraculously bonds so that it responds in concert to stress and temperature, producing a hybrid material far stronger than concrete alone. Though the cheapest building material in the world, concrete does not have to be ugly or discolored; Mr. Miodownik informs us about the latest self-cleaning concretes, cunningly infused with bacteria that scrub away the grime. New self-healing concretes can repair their own cracks, which otherwise pose great danger over time. Indeed, the proper preparation of concrete remains an essential art: More than 300,000 Haitians died in improperly cured concrete buildings that collapsed after the 2010 earthquake.

The Romans also loved glass and brought it into everyday use. Behind its familiarity, however, lies a simple but deep question: Why should something made out of melted sand be transparent? Mr. Miodownik shows us how atomic physics reverses this question: Given the vast empty spaces inside each atom, why aren't all substances transparent? Light should be able pass through easily, he observes: If an atom were the size of a stadium, the nucleus, proportionally speaking, would be a pea at the center and the electrons that orbit it mere grains of sand seated in the stands. Ingeniously extending his analogy, he imagines the energy borne by light particles as the currency that electrons must "pay" to upgrade to higher-quality (higher-energy) seats. In glass, the gaps in price between the different rows in the stadium are such that visible light does not have enough energy to bump electrons up to better seats, and thus it passes through. Gazing through a pane of glass, one is really looking at quantum mechanics, which describes the "price structure" of the atomic stadium.

Nor are the issues purely theoretical: Mr. Miodownik notes that the ancient Chinese, though so advanced in many other technologies (especially the ceramics whose secrets they held for a thousand years), disdained glass, preferring paper windows. As a result, they did not have the telescope or the microscope until Westerners brought them. Could this have been a crucial factor behind why Chinese science did not advance? As Mr. Miodownik points out, without a telescope you cannot make the observations that underpin the modern understanding of the universe; without a microscope, there was no possibility of observing cells or bacteria nor studying systematically "the microscopic world, which was essential to the development of medicine and engineering."

I will not spoil the surprise and pleasure to be found in Mr. Miodownik's wonderful treatments of chocolate, carbon, paper and cellulose, among other materials, but I must share one discovery. For years, I tried to find out whether it might somehow be possible to re-create the sky's blue color in a bottle, despite the many cubic miles of air ordinarily needed to scatter light enough to produce a perceptibly blue hue. The alternative gases that can yield a visible blue in laboratory-size experiments all turn out to be highly toxic, explosive and carcinogenic. But Mr. Miodownik introduces us to silica aerogels, exquisitely light yet solid materials—they are 99.8% air—that behave in some ways like gases. And lo, the light scattering through such an aerogel is indeed visibly blue, thanks to the same basic process of atomic scattering responsible for the sky's color. One does not even need a bottle: With a puff of aerogel, you can hold the blue sky in your hand.

Mr. Miodownik admits that however amazing materials are—the common no less than the uncommon—"we would be treated as lunatics if we spent the whole time running our fingers down a concrete wall and sighing." Though I blush to recall it, once I had the impression that materials science was dull and pedestrian. "Stuff Matters" has changed my mind; now I find myself running my fingers along things and sighing. Mr. Miodownik's lively, eloquent book changes the way one looks at the world. As he writes about the transformation of clay fired into ceramic: "It's not magic, but it is magical."

—Mr. Pesic is the author of "Sky in a Bottle" and the forthcoming "Music and the Making of Modern Science."