China shows off the under-construction Jiangmen Underground Neutrino Observatory (Juno), a sprawling subterranean laboratory that aims to crack a fundamental physics puzzle about the particles' nature faster than scientists in the United States. The giant research facility aims to solve the "mass hierarchy" problem, believed to be crucial for improving theories of particle physics, Juno's project manager Wang Yifang tells AFP during a tour of the observatory organised for international media by the Chinese Academy of Sciences, the country's national science agency. IMAGES AND SOUNDBITES