Sunday; sleuth;

Aerogel

It is also known as frozen smoke, Aerogel is the world's lowest density solid, at 96% air. It's a gel made from silicon. The liquid has been taken out and replaced with gas. Holding a small piece in your hand, it's nearly impossible to either see or feel it,  if you poke it, it feels like styrofoam.


Aerogel is useful. It supports up to 4,000 times its own weight and could  withstand a direct blast from two pounds of dynamite. It is  the best insulator in existence. It is not used  as insulator in jackets,  because it works so well that people were complaining about overheating on Mt. Everest.