The characterization of dynamical heterogeneities in many glass formers during the pas decade, both experimentally and numerically, raised a formidable interest and many open questions. Where do they come from? Why are they maximal on long time scales? Through a detailed analysis of the dynamics of frictional grain (experiment) and a molecular glass former (simulation) close to the glass transition, we propose a scenario that link the so-called “cage jumps effect” to DH, even though they occur on very different time scales.
CEA SPEC