Aerogel was previously the worlds lightest material, and it now has been dethroned by aerographite, “a sponge grown of carbon nanotubes that’s the least dense solid ever: a cubic centimeter of it weighs just two ten-thousandths of a gram.” Continue reading for a video “of two black morsels of aerographite dancing in static electricity” and more information.

The substance can also be compressed, sponge-style, by a factor of 30, and it springs right back without losing integrity. It’s electrically conductive, which means it may be used in new batteries and supercapacitors; it’s also highly resistant to chemical attack, hydrophobic, a terrific insulator, opaque to X-rays — great stuff.

[Sources 1 | 2]