So-called glass-formers are a class of highly viscous liquid materials that have the consistency of honey and turn into brittle glass once cooled to sufficiently low temperatures. Scientists have elucidated the behavior of these materials as they are on the verge of turning into glass. Although scientists do not yet thoroughly understand their behavior when approaching the glassy state, this new study, which relies on an additional type of dynamic measurements, clearly shows that they do not behave like more simple fluids, referred to as “activated” fluids.