  Glasses have liquid-like structure, but exhibit solid-like properties. A
central question concerns the relation between the structure and mechanical
properties of glasses, but structural changes remain difficult to resolve. We
use a novel combination of rheology and x-ray scattering to resolve structural
changes in colloidal glasses and link them directly to their mechanical
behavior. By combining stress and structure factor measurements, we resolve
shear induced changes in the nearest neighbor configuration as a function of
applied stress, allowing us to elucidate the structural origin of the genuine
shear banding transition of glasses.
