Welcome to the Glass Age

197 to understand the macroscopic properties of glasses. Where their ordered counterparts —crystals— offered lattice periodicity and, as a consequence, powerful theory for predicting real-world behaviour, similar tools have remained elusive in the glassy world. Disorder was often associated with randomness and chaotic dynamics. However, the sheer existence of chaos has remained disputed over ideas of infinitely complex cycles which determine the dynamics of complex networks [2]. Meanwhile, we have learnt much about the structure and dynamics of the glassy state so as to assume now the existence of order in disorder, a glass genome yet to be deciphered [3]. None of the physico-chemical definitions of the glassy state is restricted to any particular class of materials, chemical compositions or product property. Indeed, glasses exist across all classes of chemical compounds, from the classical silicate and mineral compositions to non-oxide and metallic materials, from inorganic to organic and hybrid compounds [4]. New classes of glass are frequently discovered, for example, in metal-organic frameworks, coordination polymers and, most recently, hybrid perovskite Figure 13.1. The glassmakers art relies on the viscosity-temperature characteristics of glass. Source: L. Wondraczek.