You鈥檙e looking at the lightest and warmest material on the planet. Officially, it鈥檚 called silica aerogel, but it鈥檚 so lightweight it鈥檚 referred to as frozen smoke. The substance was developed in a lab 80 years ago, and that鈥檚 pretty much where it stayed until 2007, when NASA figured out how to use it to keep instruments warm on the Mars rover. Industrial manufacturers and gear geeks have been toying with it ever since. In 2010, apparel maker put aerogel inside a jacket lining and sent mountaineer Jamie Clarke up Everest; he overheated. But designers kept tinkering, and this summer the material makes its debut in running shoes, sleeping pads, snow pants, and, yes, space suits.
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Ratio of down to aerogel needed to retain the same amount of warmthWHAT IT IS: Aerogel is 90 percent air and 10 percent silica. The silica is extremely porous, but because the holes are 1/10,000th the diameter of a human hair, they block nearly all airflow, making it supremely effective as an insulator. It鈥檚 also shockingly light: the hockey-puck-size samples shown here鈥攅nough to outfit a pair of mountaineering boots鈥攚eigh just nine-tenths of an ounce each.
HOW IT鈥橲 MADE: Silica gel is poured onto mats of polyester, which are rolled up in tubes, placed inside 12-inch-thick steel chambers, and exposed to immense pressure, turning any liquid to gas and producing a very low-density solid that can be cut into almost any shape. The only problem: what鈥檚 left is incredibly brittle. Bend it and it turns to dust.
THE BREAKTHROUGH: Last March, German aerogel maker Cabot released thin sheets of silica packaged in polyester pouches. When the silica crumbles, the threads鈥 fibers hold it in place, retaining its structure.
WHAT鈥橲 NEXT: Aerogel essentially nullifies heat transfer, so it鈥檚 being used as insulation for windows, thermoses, even paint. But it鈥檚 also breathable, so gearmakers are experimenting with it as a lightweight alternative to down. Of course, it鈥檚 still outrageously expensive (five times the price of synthetics like Thinsulate), but that will change as production increases, giving cold-weather aficionados鈥攁nd geese鈥攕omething to cheer about.