Dynamic or configurational approach to the glass transition?

The dynamic approach to the glass transition is described on the basis of the von Laue approach to thermodynamic fluctuations leading to a Levy situation for the corresponding subsystems. The configurational approach is described on the basis of the Mezard Parisi scenario using the Gibbs distribution for the calculation of an ideal glass transition at the Kauzmann temperature. Two kinds of calorimetric experiments are described which are consistent with the von Lane approach to subsystem fluctuations and which are inconsistent with the Gibbs approach to subensemble fluctuations. A specific dynamic approach is described that is not consistent with the configurational ideal glass transition. Several examples of dynamic glass transition phenomena, for different processes in the Arrhenius diagram, can qualitatively be explained by the extraordinary concentration of free volume in relatively small spatial spots caused by the preponderant Levy component for spectral densities of fluctuations for extensive thermodynamic variables. (C) 2002 Elsevier Science B.V. All rights reserved.