Figure 5: “Dynamic scaling” relation between the number of dynamically correlated particles, evaluated by the peak height of $χ4$, and relaxation timescale, $τα$, for a number of glass-formers [36], determined using the bound provided by Eq. (7). For all systems, dynamic correlations increase when the glass transition is approached. The full line through the data [36] suggests a crossover from algebraic, $χ4∼ταz$, to logarithmic, $χ4∼exp(ταψ$), growth of dynamic correlations with increasing $τα$.