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Engineering -- an endless frontier | |||||||||||
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Engineering sciences |
The phrase “engineering science” appeared at the beginning of the eighteenth century, a full six decades earlier than the appearance of the phrase “social science.” Engineering science, together with research and development, shifted into high gear after World War II. Science generally is a state of knowing or possessing knowledge that is sufficient generally, clearly conceptualized and systematized, critically examined and empirically tested. It addresses not only what is but also what can be, because it goes beyond cataloging facts to supporting contrary-to-fact hypotheses. Natural sciences concern with what can be under physical laws. Engineering sciences add the constraint of utility and ask what can be of use under physical laws and other practical constraints. An engineering science delineates the underlying principles and mechanisms for a broad type of artificial system with physical bases susceptible to deliberate design and control, for instance systems that effectively utilize heat. Utilitarian considerations open a new dimension in engineering science. Questions regarding what for, how to, and how good, which are usually absent in the contents of natural science, become central to the contents of engineering science. They are represented by functional concepts. Engineers investigate not only a system's physical structures but also its functions, or the services that it delivers to some external environment. Structures and functions are of course interrelated, but specific studies can emphasize one or the other. Engineering sciences roughly divide into two classes: physical and systems. The former distinguishes topics according to underlying mechanisms, the latter according to functions. Both are mathematical, although with their theorem-proof style, systems theories -- information, control, and computation theories -- are closer to pure mathematics. The American Society for Engineering Education (ASEE) in 1955 identified six engineering sciences: mechanics of solids, fluid mechanics, thermodynamics, transport phenomena, electromagnetism, material structures and properties. They share the basic laws and principles of the physical sciences but have developed substantial bodies of concrete details. If you go to a book on engineering thermodynamics, of course you will find the laws of thermodynamics, but you will also find control volume and many other concepts that are usually absent in physics textbooks. Engineering sciences are often integrative, because a complex system usually involves mechanisms studied in several academic disciplines. An synthetic theory, which brings knowledge from two sciences to bear on a single topic, is more than the sum of its parts, because it must introduce novel concepts to fill in the gaps, establish interfaces, and reconcile different approximations. For example, chemical engineering has synthesized chemistry and physics to produce a body of scientific knowledge useful for industrial chemical processing. With the rapid advancement of bioengineering, cell or molecular biology may well emerge as a new engineering science. ASEE also suggested a seventh candidate for engineering science: information theory. In contrast to the other six, which are all physical, information theory is a systems science. Systems theories abstract from most physical characteristics of a system and concentrate on the functions it performs. For example, information theory investigates systems that perform the function of reliably transmitting messages from a source to a destination, regardless whether the messages go through copper wires, optical fibers, or satellite links, so that its results are pertinent to all media. Three large groups of systems theories are communication (including information), control, and computation. The former two are most indigenous to engineering. The general nature of systems theory is discussed more fully in "Concepts of systems in engineering." Claude Shannon’s information theory that introduced, among other results, a mathematical definition of information in communication engineering, is probably the most famous of engineering theories. Like computers, it has been hyped by engineers and further blown up by journalists and philosophers. Like other thoughtful engineers and scientists, Shannon was disturbed about the “bandwagon” and warned: “Although this wave of popularity is certainly pleasant and exciting to those of us working in the field, it carries at the same time an element of danger. While we feel that information theory is indeed a valuable tool in providing fundamental insights into the nature of communication problems and will continue to grow in importance, it is certainly no panacea for the communication engineer or, a fortiori, for anyone else. Seldom do more than a few of nature’s secrets give way at one time. It will be all too easy for our somewhat artificial prosperity to collapse overnight when it is realized that the use of a few exciting words like information, entropy, redundancy, do not solve all problems. . . The subject of information theory has certainly been sold, if not oversold. We should now turn our attention to the business of research and development at the highest scientific plane we can maintain.” -- C. E. Shannon, The bandwagon. IEEE Transactions on Information Theory, 2: 3 (1956). Such sober and critical attitude expresses the essence of science.
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Detailed references are found under various branches of engineering. For general characteristics, see: Grinter, L. E. 1955. Report of the Committee on Evaluation of Engineering Education. Journal of Engineering Education, 44: 25-60. Slepian, D. 1976. On bandwidth. Proceedings of the IEEE, 64: 292-300. (Epistemological reflection and technical analysis of reality and its mathematical representations, based on a paradox in the bandwidth theorem). Vincenti, W. G. 1990. What Engineers Know and How They Know It: Analytical Studies from Aeronautical History. Baltimore, MD: Johns Hopkins Press. (Chapter 4 presents a case in engineering thermodynamics). |
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