Viscous materials do not follow standard laws - below a sub-melting point threshold, anyway. 

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. Researchers have examined the behavior of these materials as they are on the verge of turning into glass.  Although science does not yet thoroughly understand their behavior when approaching the glassy state, the new study relies on an additional type of dynamic measurements and clearly shows that they do not behave like more simple fluids, referred to as "activated" fluids. This is contrary to recent reports.

The dynamics of materials are described using a formula called the Arrhenius law, well known for chemical reaction rates, which regulates how temperature affects characteristics such as viscosity and relaxation times -i.e., delay in returning to equilibrium after the material has been subjected to a perturbation. 

The authors used a so-called "residuals" analysis to show that Arrhenius type dynamics is not a common behavior at temperatures between a sub-melting point threshold, called the crossover temperature, which occurs at a dynamic transition point, and the glass transition temperature, where the liquid becomes a glassy solid. 

First author Zhen Chen and the group discovered this by analyzing not only the material's viscosity but also more precise data on the dielectric relaxation time available within the same temperature range. This gave them a more exact account of relaxation dynamic properties in highly viscous materials. 

 The study revealed the need for greater precision in the viscosity data of glass-former materials to avoid masking its actual behavior from data treatment and graphical representation.

Citation: Z. Chen et al. (2012), 'On the dynamics of liquids in their viscous regime approaching the glass transition', European Physical Journal E 35: 65; DOI 10.1140/epje/i2012-12065-2