Searching for the ideal glass transition: Going to yotta seconds and beyond

Here we report results for the dynamics of a 50-million-year-old (geologically) aged Fushun amber that had a fictive temperature T f approximately 193 K below its glass transition temperature T g in the thermally rejuvenated state. The density of this ultra-stable amber was found to be 14% greater than the post-rejuvenation value. Length change dilatometry was used to map the T f by performing de-aging experiments and equilibrium state dynamics were obtained by making measurements at T = T f . Time-Temperature Superposition was applied to the frequency dependent storage and loss modulus measurements both along the equilibrium line and in upper-bound conditions where T > T f . We find that the relaxation times cover > 10 27 s (1 ronna second), i.e., thousands of yotta seconds but do not follow the “expected” Vogel-Fulcher-Tammann (VFT) type of super-Arrhenius type of temperature dependence. Rather the deep glassy state equilibrium dynamics show no evidence of divergence at a finite temperature for temperatures that would be expected to be far below the ideal glass temperature T g , i d e a l . In addition, at constant fictive temperature, we find that the relaxation times vary very strongly with specific volume v whereas, in isothermal conditions, the relaxation times are only weakly dependent on v . These results evidence that the deep glass state behavior presents a challenge to current ideas about glasses and the glass transition.