Dark MatterJet black and highly porous, a piece of Aerographite almost completely absorbs the beam from a green laser in a 2012 picture. The new champion in the "lightest in the world" category, the carbon-based material is the recent creation of a team of scientists from Germany's University of Kiel and Hamburg University of Technology."Even very thin specimens of Aerographite are fully opaque for the eye," said Hamburg's Matthias Mecklenburg.Unlike a sponge, which would "leak" or "glow" any light aimed at it, Aerographite is "not a bit transparent," he said.But, he added, our hands would hardly register its "fluffy," spongelike surface, because the innovative material is practically weightless.Electrically conductive and lighter than the previous titleholder—a nickel-based material introduced earlier this year—Aerographite has promising applications in the engineering of batteries and water-purification systems, as well as in biotechnology.(See "A Blacker Black: Darkest Known Material Created.")—Catherine Zuckerman

Photograph courtesy Stefanie Maack, CAU