Sunday, March 13, 2016

Heavy Metals

For most of human history, the infrastructure of civilization—technology, in a word—was constructed with just a handful of elements. Trees provided wood (largely carbon and hydrogen) for shelter, ships, and fuel. The Earth provided stone and clay (largely silicon) for housing and pottery. Then came copper and tin (which, combined, make bronze, hence Bronze Age). Then iron, and a new Age. Additions trickled in over ensuing millennia: The Romans mined lead to plumb their baths and sewers; the Industrial Revolution put petroleum (like wood, a hydrocarbon) and aluminum on the list of industrial necessities. But well into the 20th century, as the eminent Yale University materials scientist Thomas Graedel has written, nearly every technology that society required comprised fewer than 20 chemical elements. In a largely unremarked-upon development, that number skyrocketed in the last 30 years as digital and green technology became increasingly important. Were one to vaporize an iPhone or Prius in a mass spectrometer, the readout would display a bewildering array of unfamiliar and often unpronounceable elements: yttrium, lanthanum, praseodymium. A vaporized computer screen would reveal the presence of europium and terbium. A jet engine would reveal rhenium. Even a simple steel truck chassis would reveal niobium. None of these elements is used in large quantities, but without them, microchips and hybrid cars would be less efficient; LEDs and LCDs less bright; steel inherently weaker. And there are many other elements that today play a similar, singular role. Graedel and his colleagues have identified no fewer than 62 of these "energy-critical elements," as they call them—others call them "technology metals" or "minor metals"—without which much modern technology would work markedly less well, if it worked at all. Our now-common reliance on these obscure materials has had enormous social, economic, and environmental consequences. These are the subject of David S. Abraham's extraordinary new book, The Elements of Power: Gadgets, Guns, and the Struggle for a Sustainable Future in the Rare Metal Age...more

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