G. Biroli and P. Urbani explain in Nature Physics (2016) why standard elasticity theory breaks down in amorphous solids.

In a work just published in Nature Physics G. Biroli and P. Urbani show that in amorphous solids standard elasticity theory breaks down. At low enough temperature or high enough pressure all non-linear elastic moduli diverge. Beyond this transition, the response to deformation becomes history and time-dependent.

arXiv preprint arXiv:1601.06724