Stuff Matters: Exploring the Marvelous Materials That Shape Our Man-Made World

First Mariner Books edition 2015

Copyright © 2013 by Mark Miodownik

ALL RIGHTS RESERVED

For information about permission to reproduce selections from this book, write to Permissions, Houghton Mifflin Harcourt Publishing Company, 215 Park Avenue South, New York, New York 10003.

First published in the United Kingdom by Penguin Books Ltd 2013

www.hmhco.com

The Library of Congress has cataloged the print edition as follows:

Miodownik, Mark, author.

Stuff matters : exploring the marvelous materials that shape our man-made world / Mark Miodownik.—First U.S. edition.

pages cm

Reprint of: London : Penguin, 2013.

ISBN 978-0-544-23604-2 (hardback)

ISBN 978-0-544-48394-1 (pbk.)

1. Materials science—Popular works. I. Title.

TA403.2.M56 2014

620.1'1—dc23

2013047575

eISBN 978-0-544-23704-9

v3.0418

For Ruby, Lazlo, and Ida

Introduction

AS I STOOD ON a train bleeding from what would later be classified as a thirteen-centimeter stab wound, I wondered what to do. It was May 1985, and I had just jumped on to a London Tube train as the door closed, shutting out my attacker, but not before he had slashed my back. The wound stung like a very bad paper cut, and I had no idea how serious it was, but being a schoolboy at the time, embarrassment overcame any sort of common sense. So instead of getting help, I decided the best thing would be to sit down and go home, and so, bizarrely, that is what I did.

To distract myself from the pain, and the uneasy feeling of blood trickling down my back, I tried to work out what had just happened. My assailant had approached me on the platform asking me for money. When I shook my head he got uncomfortably close, looked at me intently, and told me he had a knife. A few specks of spit from his mouth landed on my glasses as he said this. I followed his gaze down to the pocket of his blue anorak. I had a gut feeling that it was just his index finger that was creating the pointed bulge. Even if he did have a knife, it must be so small to fit in that pocket that there was no way it could do me much damage. I owned penknives myself and knew that such a knife would find it very hard to pierce the several layers that I was wearing: my leather jacket, of which I was very proud, my gray wool school blazer beneath it, my nylon V-neck sweater, my cotton white shirt with obligatory striped school tie half knotted, and cotton vest. A plan formed quickly in my head: keep him talking and then push past him on to the train as the doors were closing. I could see the train arriving and was sure he wouldn’t have time to react.

Funnily enough I was right about one thing: he didn’t have a knife. His weapon was a razor blade wrapped in tape. This tiny piece of steel, not much bigger than a postage stamp, had cut through five layers of my clothes, and then through the epidermis and dermis of my skin in one slash without any problem at all. When I saw that weapon in the police station later, I was mesmerized. I had seen razors before of course, but now I realized that I didn’t know them at all. I had just started shaving at the time, and had only seen them encased in friendly orange plastic in the form of a Bic safety razor. As the police quizzed me about the weapon, the table between us wobbled and the razor blade sitting on it wobbled too. In doing so it glinted in the fluorescent lights, and I saw clearly that its steel edge was still perfect, unaffected by its afternoon’s work.

Later I remember having to fill in a form, with my parents anxiously sitting next to me and wondering why I was hesitating. Perhaps I had forgotten my name and address? In truth I had started to fixate on the staple at the top of the first page. I was pretty sure this was made of steel too. This seemingly mundane piece of silvery metal had neatly and precisely punched its way through the paper. I examined the back of the staple. Its two ends were folded snugly against one another, holding the sheaf of papers together in a tight embrace. A jeweler could not have made a better job of it. (Later I found out that the first stapler was hand-made for King Louis XV of France with each staple inscribed with his insignia. Who would have thought that staplers have royal blood?) I declared it exquisite and pointed it out to my parents, who looked at each other in a worried way, thinking no doubt that I was having a nervous breakdown.

Which I suppose I was. Certainly something very odd was going on. It was the birth of my obsession with materials—starting with steel. I suddenly became ultra-sensitive to its being present everywhere. I saw it in the tip of the ballpoint pen I was using to fill out the police form; it jangled at me from my dad’s key ring while he waited, fidgeting; later that day it sheltered and took me home, covering the outside of our car in a layer no thicker than a postcard. Strangely, I felt that our steel Mini, usually so noisy, was on its best behavior that day, materially apologizing for the stabbing incident. When we got home I sat down next to my dad at the kitchen table, and we ate my mum’s soup together in silence. Then I paused, realizing I even had a piece of steel in my mouth. I consciously sucked the stainless steel spoon I had been eating my soup with, then took it out and studied its bright shiny appearance, so shiny that I could even see a distorted reflection of myself in it. What is this stuff? I said, waving the spoon at my dad. And why doesn’t it taste of anything? I put it back in my mouth to check, and sucked it assiduously.

Then a million questions poured out. How is it that this one material does so much for us, and yet we hardly talk about it? It is an intimate character in our lives—we put it in our mouths, use it to get rid of unwanted hair, drive around in it—it is our most faithful friend, and yet we hardly know what makes it tick. Why does a razor blade cut while a paper clip bends? Why are metals shiny? Why, for that matter, is glass transparent? Why does everyone seem to hate concrete but love diamond? And why is it that chocolate tastes so good? Why does any material look and behave the way it does?

Since the stabbing incident, I have spent the vast majority of my time obsessing about materials. I’ve studied materials science at Oxford University, I’ve earned a PhD in jet engine alloys, and I’ve worked as a materials scientist and engineer in some of the most advanced laboratories around the world. Along the way, my fascination with materials has continued to grow—and with it my collection of extraordinary samples of them. These samples have now been incorporated into a vast library of materials built together with my friends and colleagues Zoe Laughlin and Martin Conreen. Some are impossibly exotic, such as a piece of NASA aerogel, which being 99.8 percent air resembles solid smoke; some are radioactive, such as the uranium glass I found at the back of an antique shop in Australia; some are small but stupidly heavy, such as ingots of the metal tungsten extracted painstakingly from the mineral wolframite; some are utterly familiar but have a hidden secret, such as a sample of self-healing concrete. Taken together, this library of more than a thousand materials represents the ingredients that built our world, from our homes, to our clothes, to our machines, to our art. The library is now located and maintained at the Institute of Making which is part of University College London. You could rebuild our civilization from the contents of this library, and destroy it too.

Yet there is a much bigger library of materials containing millions of materials, the biggest ever known, and it is growing at an exponential rate: the man-made world itself. Consider the photograph on page xiv. It pictures me drinking tea on the roof of my flat. It is unremarkable in most ways, except that when you look carefully it provides a catalog of the stuff from which our whole civilization is made. This stuff is important. Take away the concrete, the glass, the textiles, the metal, and the other materials from the scene, and I am left naked, shivering in midair. We may like to think of ourselves as civilized, but that civilization is in large part bestowed by material wealth. Without this stuff, we would quickly be confronted by the same basic struggle for survival that animals are faced with. To some extent, then, what allows us to behave as humans are our clothes, our homes, our cities, our stuff, which we animate through our customs and language. (This becomes clear if you ever visit a disaster zone.) The material world is not just a display of our technology and culture, it is part of us. We invented it, we made it, and in turn it makes us who we are.

The fundamental importance of materials to us is apparent from the names we have used to categorize the stages of civilization—the Stone Age, Bronze Age, and Iron Age—with each new era of human existence being brought about by a new material. Steel was the defining material of the Victorian era, allowing engineers to give full rein to their dreams of creating suspension bridges, railways, steam engines, and passenger liners. The great engineer Isambard Kingdom Brunel used it to transform the landscape and sowed the seeds of modernism. The twentieth century is often hailed as the Age of Silicon, after the breakthrough in materials science that ushered in the silicon chip and the information revolution. Yet this is to overlook the kaleidoscope of other new materials that also revolutionized modern living at that time. Architects took mass-produced sheet glass and combined it with structural steel to produce skyscrapers that invented a new type of city life. Product and fashion designers adopted plastics and transformed our homes and dress. Polymers were used to produce celluloid and ushered in the biggest change in visual culture for a thousand years: the cinema. The development of aluminum alloys and nickel superalloys enabled us to build jet engines and fly cheaply, thus accelerating the collision of cultures. Medical and dental ceramics allowed us to rebuild ourselves and redefine disability and aging—and, as the term plastic surgery implies, materials are often the key to new treatments used to repair our faculties (hip replacements) or enhance our features (silicone implants for breast enlargement). Gunther von Hagens’s Body Worlds exhibitions also testify to the cultural influence of new biomaterials, inviting us to contemplate our physicality in both life and death.

This book is for those who want to decipher the material world we have constructed and find out where these materials came from, how they work, and what they say about us. The materials themselves are often surprisingly obscure, despite being all around us. On first inspection they rarely reveal their distinguishing features and often blend into the background of our lives. Most metals are shiny and gray; how many people can spot the difference between aluminum and steel? Woods are clearly different from each other, but how many people can say why? Plastics are confusing; who knows the difference between polythene and polypropylene? I have chosen as my starting point and inspiration for the contents of this book the photo of me on my roof. I have picked ten materials found in that photo to tell the story of stuff. For each I try to uncover the desire that brought it into being, I decode the materials science behind it, I marvel at our technological prowess in being able to make it, but most of all I try to express why it matters.

Along the way, we find that, as with people, the real differences between materials are deep below the surface, a world that is shut off from most unless they have access to sophisticated scientific equipment. So to understand materiality, we must necessarily journey away from the human scale of experience into the inner space of materials. It is at this microscopic scale that we discover why some materials smell and others are odorless; why some materials can last for a thousand years and others become yellow and crumble in the sun; how it is that some glass can be bulletproof, while a wine glass shatters at the slightest provocation. The journey into this microscopic world reveals the science behind our food, our clothes, our gadgets, our jewelry, and of course our bodies.

But while the physical scale of this world is much smaller, we will find that its timescale is often dramatically bigger. Take, for example, a piece of thread, which exists at the same scale as hair. Thread is a man-made structure at the limit of our eyesight that has allowed us to make ropes, blankets, carpets, and, most importantly, clothes. Textiles are one of the earliest man-made materials. When we wear a pair of jeans, or any other piece of clothing, we are wearing a miniature woven structure, the design of which is much older than Stonehenge. Clothes have kept us warm and protected for all of recorded history, as well as keeping us fashionable. But they are high-tech too. In the twentieth century we learned how to make space suits from textiles strong enough to protect astronauts on the Moon; we made solid textiles for artificial limbs; and from a personal perspective, I am happy to note the development of stab-proof underwear woven from a synthetic high-strength fiber called Kevlar. This evolution of our materials technologies over thousands of years is something I return to again and again in this book.

Each new chapter presents not just a different material but a different way of looking at it—some take a primarily historical perspective, others a more personal one; some are conspicuously dramatic, others more coolly scientific; some emphasize a material’s cultural life, others its astonishing technical abilities. All the chapters are a unique blend of these approaches, for the simple reason that materials and our relationships with them are too diverse for a single approach to suit them all. The field of materials science provides the most powerful and coherent framework for understanding them technically, but there is more to materials than the science. After all, everything is made from something, and those who make things—artists, designers, cooks, engineers, furniture makers, jewelers, surgeons, and so on—all have a different understanding of the practical, emotional, and sensual aspect of their materials. It is this diversity of material knowledge that I have tried to capture.

For instance, the chapter on paper is in the form of a series of snapshots not just because paper comes in many forms but because it is used by pretty much everyone in a myriad of different ways. The chapter on biomaterials, on the other hand, is a journey deep into the interstices of our material selves: our bodies, in fact. This is a terrain that is rapidly becoming the Wild West of materials science, where new materials are opening up a whole new area of bionics, allowing the body to be rebuilt with the help of bio-implants designed to mesh intelligently with our flesh and blood. Such materials have profound ramifications for society as they promise to change fundamentally our relationship with ourselves.

Because everything is ultimately built from atoms, we cannot avoid talking about the rules that govern them, which are described by the theory known as quantum mechanics. This means that, as we enter the atomic world of the small, we must abandon common sense utterly, and talk instead of wave functions and electron states. A growing number of materials are being designed from scratch at this scale, and can perform seemingly impossible tasks. Silicon chips designed using quantum mechanics have already brought about the information age. Solar cells designed in a similar way have the potential to solve our energy problems using only sunshine. But we are not there yet, and still rely on oil and coal. Why? In this book I try to shed some light on the limits of what we can hope to achieve by examining the great new hope in this arena: graphene.

The central idea behind materials science is that changes at these invisibly small scales impact a material’s behavior at the human scale. It is this process that our ancestors stumbled upon to make new materials such as bronze and steel, even though they did not have the microscopes to see what they were doing—an amazing achievement. When you hit a piece of metal you are not just changing its shape, you are changing the inner structure of the metal. If you hit it in a particular way, this inner structure changes in such a way that the metal gets harder. Our ancestors knew this from experience even though they didn’t know why. This gradual accumulation of knowledge got us from the Stone Age to the twentieth century before any real appreciation of the structure of materials was understood. The importance of that empirical understanding of materials, encapsulated in such crafts as the blacksmith’s, remains: we know almost all of the materials in this book with our hands as well as our heads.

This sensual and personal relationship with stuff has fascinating consequences. We love some materials despite their flaws, and loathe others even if they are more practical. Take ceramic. It is the material of dining: of our plates, bowls, and cups. No home or restaurant is complete without this material. We have been using it since we invented agriculture thousands of years ago, and yet ceramics are chronically prone to chip, crack, and shatter at the most inconvenient times. Why haven’t we moved to tougher materials, such as plastic or metal for our plates and cups? Why have we stuck with ceramic despite its mechanical shortcomings? This type of question is studied by a vast variety of academics, including archaeologists and anthropologists, as well as designers and artists. But there is also a scientific discipline especially dedicated to systematically investigating our sensual interactions with materials. This discipline, called psychophysics, has made some very interesting discoveries. For instance, studies of crispness have shown that the sound created by certain foods is as important to our enjoyment of them as their taste. This has inspired some chefs to create dishes with added sound effects. Some potato chip manufacturers, meanwhile, have increased not just the crunchiness of their chips but the noisiness of the chip bag itself. I explore the psychophysical aspects of materials in a chapter on chocolate and show that it has been a major driver of innovation for centuries.

This book is by no means an exhaustive survey of materials and their relationship to human culture, but rather a snapshot of how they affect our lives, and how even the most innocuous of activities like drinking tea on a roof is founded on a deep material complexity. You don’t have to go into a museum to wonder at how history and technology have affected human culture; their effects are all around you now. Most of the time we ignore them. We have to: we would be treated as lunatics if we spent the whole time running our fingers down a concrete wall and sighing. But there are times for such contemplation: being stabbed in a Tube station was one of them for me, and I hope this book provides another for you.

1

Indomitable

I HAD NEVER BEEN asked to sign a non-disclosure agreement in the bathroom of a pub before, so it came as something of a relief to discover that this was all that Brian was asking me to do. I had met Brian for the first time only an hour earlier. We were in Sheehan’s, a pub in Dun Laoghaire that wasn’t far from where I worked at the time in Dublin. Brian was a red-faced man in his sixties with a walking stick for his bad leg. He was smartly dressed in a suit and had thinning gray hair with a yellowish tinge. He chain-smoked Silk Cut cigarettes. Once Brian found out that I was a scientist he guessed rightly that I would be interested to hear stories of his life in London in the 1970s, when he was in the right place at the right time to trade Intel 4004 silicon chips, which he imported in boxes of twelve thousand for £1 each and sold in small batches to the fledgling computer industry for £10 each. When I mentioned that I was researching metal alloys in the Mechanical Engineering Department of University College Dublin, he looked pensive and was quiet for the first time. I took this as an opportune moment to head to the bathroom.

The non-disclosure agreement was scrawled on a piece of paper which he had clearly just ripped out of his notebook. The contents were brief. They stated that he was going to explain his invention to me but I had to keep it confidential. In return he was to pay me one Irish pound. I asked him to tell me more, but he comically mimed the zipping of his lips. I wasn’t quite sure why we had to have this conversation in a bathroom stall. Over his shoulder I saw other drinkers come in and out of