An introduction to the phenmenon of luminescence

The phenomenon of fracture has been associated with man's life for better or worse. since the beginning of human existence in prehistoric days, man utilized brittle fracture in shaping of stone tools and carving of houses out of rocks, although he felt its less fortunate consequences when he got his bones broken. Quarrying, shaping and structural fitting of stones the essential processes of ancient construction, all depends upon controlled manipulation of brittle fracture. Likewise today many industrial manufacturing and constructional processes, machining of materials for example, involve brittle fracture at some point. Fracture of phosphors give rise to luminescence. The present paper reports the elementary idea about luminescence, its type and applications.