This photo taken at Zhejiang University on March 19, 2013, shows aerogel developed by the university's nanometer-macromolecule research group. Gao Chao, a professor at the macromolecule and engineering science department of the university, developed this material in 2012, and it replaced a 0.18-milligram-per-cubic-centimeter German aerogel as the "world's lightest solid material." [Photo/IC]