So Cool!

The Big Lizard got here first but this is just so cool that I wanted to throw in a few cents.

Aerogel is one of the weirdest man-made substances on the planet. First, it's the lightest stuff in the world -- literally: An evacuated form of aerogel is a solid, but is actually less dense than air (meaning it would "float" on air).
But it's also an amazing insulator against both cold and heat; it's an excellent dessicant, or drying agent; it can mimic a biological cell, absorb oil, lead, and mercury pollutants... and aerogel armor can even protect against impact from bullet or bomb... or maybe even a car crash.

Why would something so light, be so strong or more correctly put more impact resistant? The foam structure allowed the tensile stresses to be converted into compressive stresses, much like an arch. The amount of these micro arch (actually they are spheres) in an aerogel has to be phenomenal. That means it has the ability to redirect outside stresses over a very large area. The more a stress or force is focus, the more penetrating power it has. This material takes things in the opposite direction by spreading out the force.

The insulator aspect is tied in to the structure also.

Another striking property of aerogels is their internal surface area. This is very difficult to measure, but can be estimated by the rate of adsorption and desorption of nitrogen. The internal surface area of an aerogel can be as high as 1000m2/g. For a sample of typical density, a cube an inch square would have as much internal surface area as ten copies of the Greater Vancouver Yellow Pages.

The better, more efficient insulators use the concept of trapped air to reduce convective and conductive heat transfer. The two biggest factors is the degree to which air flow is eliminated and he amount of solid material surrounding the air. For both instances the less is better and that is exactly what the aerogel deliverers.

This is a substance straight out of sci-fi but within our reach. Houses will need less energy to keep warm or cool. The environment can be cleaned up easier. Soldiers will be protected better. Vehicles can be made lighter, safer and more fuel efficient. The big stumbling block of course is manufacturing cost and that is looking better.