Aerogels are an amazing material for a variety of reasons. But one of the big ones in relation to energy modeling and buildings is their amazing properties of insulation. Hell, they are the reference image on the R-value wikipedia page.
So what are aerogels? They are the lightest solid in the world, due to their extremely porous nature, being over 90% air. They were first discovered in the 1931's when two chemists bet who could replace the liquid in a gel material with a gas without causing the original form of the gel to be altered. The resulting material where the liquid component of the gel has been extracted though supercritical...