To all four of us, Carsten was the best possible friend and colleague. To Finn, he was a fellow student in the history of science for several years at the Niels Bohr Institute; to Relge, he was a welcome resource for personal and intellectual interac- tion in an otherwise less than fertile environment for the history of science; Roger was Carsten's friend and advisor, not least in the development of the dissertation on which the present book is based;...