“GLASSES”
by Professor J.A. Erwin Desa, Department of Physics, Goa University, Goa

Glasses have been with us since the Stone Age and continue to be one of the most commonly used materials. The manufacture and invention of glasses for purposes ranging from containers and window panes to stained glass and special filters preceded any serious understanding of their microscopic structures or other physical properties.

Various definitions of the vitreous state are discussed here, as are some of the typical methods of characterizing these solids/liquids. The challenges of quantitatively describing this familiar material are best appreciated by considering the study of three different oxide glasses viz. a rare-earth phosphate, a rare-earth borate and a porous silicate.