Introductory Remarks

Abstract

In the past, the development of solid state physics has been based very strongly, perhaps excessively so, on the concept of the ideal crystal and the resulting periodicity and symmetry. One of the key areas for future development is the study of amorphous or disordered solids. This study is of interest not only because of what it will tell us about amorphous solids but also because of what it will tell us about the basic concepts of the solid state physics of crystals. For example, until the recent work of Weaire and his collaborators, which is ably summarized by Weaire and Thorpe, most of us believed that the existence of a gap was a result of the periodicity and symmetry of the lattice structure. Weaire has shown that, at least for his simple Hamiltonian, the gap results from the short range order of the atoms. Bloch’s theorem is sufficient but not necessary! The study of amorphous solids is of interest not only because of what we can learn. In addition to these friendly intellectual pursuits we have the exciting prospects for technological advances. All in all I feel that the study of amorphous solids is one of the exciting frontiers of physics. Thus, it is highly appropriate that this should be the concluding session of this conference. The dessert should be served last.