Aerogel

Aerogel is a synthetic porous ultralight material derived from a gel, in which the liquid component of the gel has been replaced with a gas. The result is a solid with extremely low density and thermal conductivity. It is nicknamed frozen smoke, solid smoke, solid air or blue smoke owing to its translucent nature and the way light scatters in the material; however, it feels like expanded polystyrene (styrofoam) to the touch.