COMMUNICATION ERA undertakings dominate postindustrial economies. Since the late 1970s, knowledge, information, education, and entertainment enterprises in the U.S. have accounted for over 50% of all jobs. Today, this group of activities generate about 66% of jobs and Gross Domestic Product. These calculations vary, depending upon what is counted. One thing about this era is clear, though--brains, not brawn, have become the key resource.
Computers, ranging from massive supercomputers to ubiquitous handheld "personal assistant" PCs, are the economic linchpin. The current information revolution ushered in a vast new range of services: pay cable TV; interactive television; teleconferencing; video recording; electronic funds transfer systems, shopping, and mail; facsimile newspapers and specialized magazines on video; electronic plebiscites on vital public policy issues; automatic home security services (fire, police, flood, storm, etc.); special services for the handicapped; and home computers to handle a vast growing range of activities.
Solid-state devices, microelectronics, computers, and communications equipment of all kinds are today's economic mainsprings. Computer household penetration rose from 27% in 1990 to 51% in 2001. Integrated circuit chips fashioned from flyspecks of rare earths and traces of silicon marshal knowledge and information that can change the fate of a business or an empire.
Better communication means have been introduced throughout history. Improved methods of communication displace the less-effective and become the dominant mode. Spoken words preceded the handwritten word, which gave way to the mechanically printed word, that was eclipsed by the telegraph and telephone. Four major communication modes, each one more efficient than the preceding one, dominated eras of American economic growth over the past century: the low-cost "penny press," which made inexpensive mass-circulation newspapers and periodicals available to an increasingly literate populace; regular radio broadcasting that began during the mid 1920s; television, starting in the 1950s; and computers that flooded consumer markets by the late 1970s.
Computers of the 1960s and 1970s were big, costly, few in number, and limited to top-management use. During the 1980s, desktop PCs lopped off middle-management paper-pushers, and decentralized decisionmaking. Takeoff during the 1990s greatly enlarged computer networking, and the Internet provided access to the fund of human knowledge.
Science constantly seeks faster, better, more-efficient, less-costly, and more-streamlined technologies. Communication advances can be categorized into at least seven successive stages of development:
1. Physical/mechanical. Thomas Alva Edison's primitive phonograph utilizing a mechanically vibrating pickup and diaphragm to reproduce sound, commercially introduced in 1877, exemplifies this introductory stage. Forerunners of modern computers can be traced back to the hand-manipulated abacus. Later on came Charles Babbage's calculating engine that was partially constructed between 1822 and 1871.
2. Electromechanical. Alexander Graham Bell's telephone, introduced in 1876, demonstrates this type of innovation using electric pulses to vibrate a diaphragm or open and close an audible circuit. Computer antecedents are characterized by Herman Hollerith's electrically operated tabulator, which utilized printed punched cards, that was used to process 1890 census data.
3. Fully electronic. Guglielmo Marconi's first wireless telegraph signals (precursor to the radio), demonstrated in 1895, represent this principle. The earliest numeric analog computer, the Electronic Numerical Integrator and Computer (ENIAC), was developed in 1946.
4. Electro-optical. This development is characterized by telephone analog switching systems converting signals to photonics.
5. Optical/photonic. Light transmission is the latest communications frontier. …