The Hunt for Quasicrystals Sharon Glotzer Enjoys a Riveting Tale of Derring-Do in Materials Science

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MATERIALS SCIENCE The hunt for quasicrystals Sharon Glotzer enjoys a riveting tale of derring-do in materials science.

icture this. In Russia’s far east, a The Second Kind of Impossible: The Steinhardt’s story begins in Pasadena, motley crew of conspirators races Extraordinary Quest for a New Form of California, in 1985. Then on the faculty against time to solve a mystery hidden Matter at the University of Pennsylvania in Pfor billions of years. The enigma could link PAUL J. STEINHARDT Philadelphia, Steinhardt had given a talk at Simon & Schuster (2018) a speck of rock found in the dusty base- his undergraduate alma mater, the California ment of an Italian museum to the evolution Institute of Technology, where he explained of the Solar System. To solve it, a brilliant 1980s, but the interpretations proffered to physicist Richard Feynman, his former theoretical physicist must overcome impos- for them were not accepted by many in the professor, a theory that he had devised with sible odds, Kremlin agents, a vanished scientific community, bar physicists, for doctoral student Dov Levine. This predicted package, secret diaries and a trek across a some time. After all, they upset nearly two the possibility of quasicrystals, with sym- volcanic peninsula. centuries of scientific understanding about metries technically possible but extremely This is no Hollywood blockbuster: it is the structure of matter. French priest René- unlikely: the “second kind of impossible”. real-world scientific derring-do. In The Just Haüy’s 1801 Second Kind of Impossible, theoretical Treatise of Miner- “Steel hardened FORBIDDEN STRUCTURE physicist Paul Steinhardt relates his bold alogy established by small Since the late 1970s, Steinhardt had quest to find a natural quasicrystal, a form that solids con- quasicrystal imagined that ‘forbidden’ crystals with of matter with an unusual arrangement of tain microscopic five-fold symmetry might be possible if,

particles is used KIND OF IMPOSSIBLE , SIMON AND SCHUSTER THE SECOND ALISON FORNER/ atoms thought impossible for a crystal. The building blocks in needles for on cooling, atoms were arranged into a result is a mix of sober, lab-bound scientific and that all ele- acupuncture and space-spanning network of icosahedra. memoir and rollercoaster adventure, packed ments and mix- surgery, dental He and Levine experimented first with with discovery, disappointment, exhilaration tures thereof can, styrofoam balls and pipe cleaners, and and persistence. at least in principle, instruments and later with paper models. They looked to In crystals, atoms are arranged in a be found in crystal razor blades.” Penrose tilings, in which two shapes com- repeating pattern. In quasicrystals, they form, from sucrose bine to create a non-repeating pattern, not are still ordered but the pattern is not peri- to sapphire. Despite thousands of possible unlike those seen in classical Islamic tiling. odic: it doesn’t repeat. This oddity results in atomic arrangements, the rules to describe They realized that by drawing parallel lines unexpected rotational symmetries (differ- crystals were simple: the materials could on a Penrose tiling, they could prove that ent from, say, that of a square lattice, which have only two-, three-, four- or six-fold the tiles are arranged quasiperiodically, repeats itself four times in a full rotation). symmetry. Until quasicrystals’ discovery producing five-fold symmetry. This was Quasicrystals were first discovered in the violated them. the breakthrough they needed. The leap

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A model of a to three dimen- quasicrystal structure. sions produced Steinhardt’s long- Books in brief imagined icosahedral quasicrystal. Unknown to them, a couple of hundred Borrowed Time kilometres away, a materials scientist had Sue Armstrong Bloomsbury (2019) obtained a diffraction pattern unlike any Is death genetically programmed? Is ageing a disease? Engrossing he had seen before — for a rapidly cooled questions throng science writer Sue Armstrong’s round-up of research alloy of aluminium and manganese. The on the biology of ageing. She brings us up to speed on the illuminating researcher was Dan Shechtman, and he was (if partial) answers through work by the likes of biologist Tom Kirkwood working at the National Bureau of Standards on the ‘disposable soma’ theory of limited resources; Nobel laureates (now the National Institute of Standards and Elizabeth Blackburn, Carol Greider and Jack Szostak on telomeres, the Technology) in Gaithersburg, Maryland. end caps of chromosomes; evolutionary biologist Steven Austad on The diffraction pattern had ten-fold rota- the long-lived clam Arctica islandica; and various Alzheimer’s disease tional symmetry. Astonished, Shechtman specialists. A rich, timely study for the era of ‘global ageing’. drew its concentric rings of ten dots in his lab book, writing “10-fold???” next to it. He didn’t know it yet, but he had just discovered Chasing the Sun the first quasicrystal. In 2011, he won the Linda Geddes Profile (2019) Nobel Prize in Chemistry for it. Light pollution, indoor lifestyles and glowing screens can play Steinhardt and Levine, recognizing the havoc with our health. So shows science writer Linda Geddes in collective implications, published a paper on her deft study of chronobiology, the science of organismic cycles in their theory in Physical Review Letters, laying relation to solar rhythms. Geddes marshals an array of findings on the foundations of the field of quasicrystal everything from the suprachiasmatic nucleus — the cluster of cells research (D. Levine and P. J. Steinhardt Phys. in the brain that acts as the body’s master clock — to US Amish Rev. Lett. 53, 2477; 1984). communities living dawn to dusk and off grid, and submarine Hundreds of quasicrystals with different crews who rarely see the Sun. She even turns guinea pig to test symmetries have now been made in the lab. measurable benefits from candlelight and outdoor exercise. Non-stick frying pans were among the first applications of quasicrystals, owing to the alloys’ low friction, high hardness and low The Human Tide surface reactivity. Steel hardened by small Paul Morland John Murray (2019) quasicrystal particles is used in needles for The Industrial Revolution sparked a triple boom: in technology, acupuncture and surgery, dental instru- population and emigration. In this sweeping treatise spanning the ments and razor blades. Quasicrystals have past 200 years, demographer Paul Morland traces the surge of been discovered in materials other than humans in numbers and on the move, and the transformations metals, including polymers and mixtures wrought by this accelerating “demographic whirlwind” on of nanoparticles. Computer simulations individuals, nations and empires. It’s an extraordinary ebb and suggest that quasicrystals should be even flow, from the 4 million Italians who poured into the United States more ubiquitous. in the 35 years before the First World War to today’s tide of African All these quasicrystals were human- children making harrowing journeys across the Mediterranean. made, but Steinhardt became curious about naturally occurring ones. In 1999, now on the faculty at Princeton University in New The Truth About Fat Jersey, he set out on a quest that few theoreti- Anthony Warner Oneworld (2019) cal physicists could imagine — to find one. In this trenchant manifesto-cum-study, Anthony Warner (aka the This is the true heart of his book. Angry Chef) takes a honed knife to flabby theorizing about what makes us fat. He examines proven and putative drivers, including GLOBAL HUNT hormones such as leptin, calories, genetic factors, the human Steinhardt started by looking to the past microbiome, inactivity, dietary fats and carbohydrates, environment — in museums, which have huge collec- and poverty. Given the complexities of the findings, Warner tions of mineral samples from around argues for a system-level solution involving public-health officials the world. Perhaps, he surmised, one of and communities. He also calls for an end to the moral panic these was a misidentified quasicrystal. He surrounding fat. A nuanced approach to this global issue. assembled a crack team of fellow hopefuls — including a geoscientist, an electron microscopist and an undergraduate — and Interplanetary Robots the hunt began. Years of combing through Rod Pyle Prometheus (2019) dusty archives turned up nothing, until On 15 July 1965, NASA’s Mariner 4 probe sent back grainy a box from the Museum of Natural His- images of Mars, revealing a forbidding surface that destroyed tory in Florence, Italy, arrived at Prince- florid Victorian speculation in a trice. Over the next 50 years, ton containing a nearly invisible speck of robotic missions researched the rest of Earth’s planetary a rare mineral, khatyrkite. On 2 January neighbours. Space writer Rod Pyle tours craft from the Soviet 2009, the researchers became certain that Luna 3, which snapped the Moon’s far side in 1959, to NASA’s they had discovered a natural quasicrystal New Horizons and its 2015 fly-by of Pluto. Sandwiched between (later named icosahedrite). But where did these are tales of the Voyagers, Galileo, Cassini and more. Geeky it come from? escapism at its best. Barbara Kiser

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The sample, they deduced after PHYSICS many unexpected twists and turns, had probably been found on Russia’s remote, volcanic Kamchatka Peninsula. Steinhardt led an expedition there in Dreaming of death rays 2011 — a wild scavenger hunt search- ing for the stream that the team thought Lasers have long held allure for physics, the military contained the original source. The and science fiction, finds Luke Fleet. group ultimately worked out that the speck came from a meteorite that also contained a second natural quasicrystal, asers first emerged nearly 60 years of the current US dubbed decagonite. ago, but the idea of using powerful president), declared This book is a front-row seat to history beams of heat or light is hardly new. it too speculative. as it is made. For quasicrystal aficionados LIn the third century bc, for instance, Greek The United States like me, it is riveting. For anyone who has scientist Archimedes allegedly used mirrors was hardly alone in reflecting the Sun’s rays to attack Roman its fervour for a death ships off Sicily. Millennia later, ‘death rays’ — ray. Before the Sec- concentrated light or electricity — became ond World War, the a science-fiction trope, from H. G. Wells’s British air ministry 1898 The War of the Worlds to the Star Wars offered a bounty of franchise. Lasers, Death £1,000 (more than Rays, and the As often happens, futurist fiction sparked Long, Strange £60,000 (US$76,000) the real thing. And that’s the story told in Quest for the today) to anyone TRUSTEES OF PRINCETON UNIV. OF PRINCETON TRUSTEES Lasers, Death Rays, and the Long, Strange Ultimate Weapon who could craft and Quest for the Ultimate Weapon. JEFF HECHT demonstrate a ‘ray As the title indicates, Jeff Hecht’s book Prometheus (2019) weapon’ that could is not about the mundane, ubiquitous kill a sheep at 100 lasers of supermarket checkouts and CD metres. (This was ambitious: by the end of players. Hecht, a science writer who has the Second World War, the Japanese mili- covered lasers since the 1970s, instead tary could still only kill rabbits at 30 metres records efforts to adapt the technology for using microwave tubes.) By the 1950s, a military use. In 1934, for instance, inventor new invention was about to focus minds. Nikola Tesla — instrumental in developing The laser, as Hecht makes clear, was a the alternating-current electricity system technology intertwined with politics. The — announced that he had attempted to star figure is physicist Gordon Gould. design a device that would send a ‘death In the late 1950s, Gould explored using beam’ of concentrated particles to detect light to optically ‘pump’ a maser — a Paul Steinhardt with a quasicrystal model. and destroy submarines. As Hecht relates, device emitting microwaves at a specific US government agents looked into the pro- frequency, invented by physicist Charles dreamt of finding a scientific needle in posal after Tesla’s death, but reviewer John Townes in 1953. This was, in essence, the a haystack, it is exhilarating. Steinhardt G. Trump, an electrical engineer (and uncle first conceptualization of a laser, which strikes a balance between mathematical detail and accessibility. He captivates with vivid details about his wonder, frustrations and even a few moments of unleashed ego. We learn about the deep ESVA/AIP/SPL relationships and bold ideas that kept his journey on course. This nail-biting narrative reminds us that the thrill of scientific discovery is not found in a single eureka moment. It is instead marked by determination, team work, optimism and, importantly, luck. Contemplating Julia 89, an aster- oid orbiting the Sun between Mars and Jupiter that could be the source of the fateful meteorite, The Second Kind of Impossible ends as it begins — with the possibility of impossibility. ■

Sharon Glotzer is the John Werner Cahn Distinguished University Professor of Engineering at the University of Michigan in Ann Arbor, and the Anthony C. Lembke Chair of the Department of Chemical Engineering. e-mail: [email protected] Gordon Gould (left, with Ben Senitsky) experimented with microwave lasers in the 1950s.