What are the frontiers of today's communications technology? The Age of Electronic Messages explains the scientific principles on which this technology is based and explores its capabilities and limitations, its risks and benefits.In straightforward language accompanied by numerous illustrations, Truxal describes the communications technology that has become such an integral part of today's work and leisure. He provides accounts of the bar codes used in supermarkets and the postal system of the way signals are described in terms of frequencies and in digital form of hearing and audio...