NYT article on aerogel. "In the 1980's, Dr. Tsou and others began to work with the material. 'It has 14 Guinness Book of World Records-type properties,' Dr. Tsou said. 'It's the lowest density of any solid, and it has the highest thermoinsulation properties. Though it would be very expensive, you could take a two- or three-bedroom house, insulate it with aerogel, and you could heat the house with a candle. But eventually the house would become too hot.'"