This book contains the papers presented at a conference organised in honour of H.B.G. Casimir's 80th birthday. Outstanding scientists from different fields of research were invited to discuss important recent developments and put them in a broader perspective.The resulting book is devoted to the following relationships between fundamental physical research and technological developments:- - the prognoses of technologically relevant phenomena on the basis of physical research; - the dependence of technological developments on physical research; - the spin-off of physical research for other disciplines; - the fact that fundamental research is required for the advancement of physics in general and of applied physics in particular. The famous Dutch physicist H.B.G. Casimir has made substantial contributions to the development of 20th century physics and was for several years head of Philips Research Laboratories. The diversity of topics addressed in this book reflects his wide range of interests.