Solid Light: When Massless Photons Bind and Carry WeightPublished on14 July 2026solid-lightphotonsquantum-opticstechnologyneo-babylonworldbuildingcyberpunkIn 2013 Harvard bound two photons into a molecule; in 1999 light was slowed to 17 m/s. The real physics behind solid light, and the wall it could build.