Researchers have used synchrotron radiation-based quasi-elastic scattering with time-domain interferometry and multi-line gamma rays to study supercooled liquids. The experiments appear to have provided insights into the dynamics of these liquids, including the crossover of quasi-localized dynamics and diffusion, and the structure of strongly supercooled molecular liquids. The studies also seem to have shed light on the Johari-Goldstein relaxation in certain glass-forming materials.