Some comments on the nature of universal properties in low-temperature   glasses
  We discuss the recent theory of Burin and Kagan that attempts to explain the existence of universal low temperature properties in amorphous solids. We suggest a realistic experimental scenario that could be used to test the theory. We comment on the results of an experiment that has already been performed in the proposed geometry. 
David R. Reichman, Peter Neu, and Robert J. Silbey (MIT)