Spin-exchange scattering time in spin glasses

We present a calculation of the spin-exchange scattering time ${\tau }_s$ for a spin glass. This quantity was measured in recent superconducting tunneling measurements. Our results for $\frac{1}{{\tau }_s}$ are consistent with these experiments. It is argued that a previous calculation, which claimed that the temperature dependence of $\frac{1}{{\tau }_s}$ directly reflected that of the spin-glass order parameter, is incorrect.