Aerogels are the Worlds Lightest Solids

Aerogels are the world’s lightest (least dense) solids. They are also excellent thermal insulators and have been used in numerous Mars missions and the Stardust comet particle-return mission.

The focus of this video by Veritasium is silica aerogels, though graphene aerogels are now technically the lightest.

Original Article : HERE ; The Ultimate Survival Food: The Lost Ways