Cooked up in a NASA laboratory, a gel that is 99.8 percent air has been designated the least dense solid in the world by Guinness World Records.
Aerogel, one of the world’s lightest solids, can withstand a direct blast of 1kg of dynamite and protect against heat from a blowtorch at more than 1,300C.
The substance, described as “frozen smoke” for its hazy blue appearance, is a new variety of a silicon-based material designed to collect particles in deep space.
