Engineering is the profession in which a knowledge of the mathematical and natural sciences gained by study, experience and practice is applied with judgment to develop ways to utilize, economically, the materials and forces of nature for the benefit of mankind. The result is the design, production, and operation of useful objects or processes.
History and Etymology
In prehistoric times, men and women had to be ingenious in order to survive hunger, enemies, climate and, later, the tyranny of distance. So there have always been 'engineers' around, many of whom were involved in activities we would not associate with engineering today but, rather, with hunting, farming, fishing, fighting, implement- and tool-making, transportation and many other things.
The Greeks - the inventors - made significant contributions in the 1000 years that straddled the BC-AD divide. They produced the screw, the ratchet, the water wheel and the aeolipile, better known as Hero's turbine. The Romans - the improvers and adapters - did likewise, building fortifications, roads, aqueducts, water distribution systems and public buildings across the territories and cities they controlled. At the other end of the world, the Chinese have been credited with the development of the wheelbarrow, the rotary fan, the sternpost rudder that guided their bamboo rafts and, later, their junks. They also began making paper from vegetable fibres - and gunpowder.
The so-called 'Dark Ages' (roughly, 500 to 1500 AD) that followed still produced some things that were ingenious. For example, there was the development of the mechanical clock and the art of printing. There was the technique of heavy iron casting that could be applied to products for war, religion and industry - for guns, church bells and machinery. These 'Dark Ages' were followed by the Renaissance of the 16th century, which the engineer/inventor/artist Leonardo Da Vinci dominated. But this whole period came under the influence of the architect/engineer, who built cathedrals and other large buildings, and the military engineer who built castles and other fortifications. The forerunners of engineers, practical artists and craftsmen, proceeded mainly by trial and error. Yet tinkering combined with imagination produced many marvelous devices. Many ancient monuments cannot fail to incite admiration. The admiration is embodied in the name “engineer” itself. It originated in the eleventh century from the Latin ingeniator, meaning one with ingenium, the ingenious one. The name, used for builders of ingenious fortifications or makers of ingenious devices, was closely related to the notion of ingenuity, which was captured in the old meaning of “engine” until the word was taken over by steam engines and its like. Leonardo da Vinci bore the official title of Ingegnere Generale. His notebooks reveal that some Renaissance engineers began to ask systematically what works and why.
The first phase of modern engineering emerged in the Scientific Revolution. Galileo’s Two New Sciences, which seeks systematic explanations and adopts a scientific approach to practical problems, is a landmark regarded by many engineer historians as the beginning of structural analysis, the mathematical representation and design of building structures. This phase of engineering lasted through the First Industrial Revolution, when machines, increasingly powered by steam engines, started to replace muscles in most production. While pulling off the revolution, traditional artisans transformed themselves to modern professionals. The French, more rationalistic oriented, spearheaded civil engineering with emphasis on mathematics and developed university engineering education under the sponsorship of their government. The British, more empirically oriented, pioneered mechanical engineering and autonomous professional societies under the laissez-faire attitude of their government. Gradually, practical thinking became scientific in addition to intuitive, as engineers developed mathematical analysis and controlled experiments. Technical training shifted from apprenticeship to university education. Information flowed more quickly in organized meetings and journal publications as professional societies emerged.
The second industrial revolution, symbolized by the advent of electricity and mass production, was driven by many branches of engineering. Chemical and electrical engineering developed in close collaboration with chemistry and physics and played vital roles in the rise of chemical, electrical, and telecommunication industries. Marine engineers tamed the peril of ocean exploration. Aeronautic engineers turned the ancient dream of flight into a travel convenience for ordinary people. Control engineers accelerated the pace of automation. Industrial engineers designed and managed mass production and distribution systems. College engineering curricula were well established and graduate schools appeared. Workshops turned into to laboratories, tinkering became industrial research, and individual inventions were organized into systematic innovations.
Research and development boomed in all fields of science and technology after World War II, partly because of the Cold War and the Sputnik effect. The explosion of engineering research, which used to lagged behind natural science, was especially impressive, as can be seen from the relative expansion of graduate education. Engineering was also stimulated by new technologies, notably aerospace, microelectronics, computers, novel means of telecommunications from the Internet to cell phones. Turbojet and rocket engines propelled aeronautic engineering into unprecedented height and spawned astronautic engineering. Utilization of atomic and nuclear power brought nuclear engineering. Advanced materials with performance hitherto undreamed of poured out from the laboratories of materials science and engineering. Above all, microelectronics, telecommunications, and computer engineering joined force to precipitate the information revolution in which intellectual chores are increasingly alleviated by machines. To lead the progress of these sophisticated technologies, engineers have remade themselves by reforming educational programs and expanding research efforts. Intensive engineering research produced not only new technologies but also bodies of powerful systematic knowledge: the engineering sciences and systems theories in information, computer, control, and communications. Engineering developed extensive theories of its own and firmly established itself as a science of creating, explaining, and utilizing manmade systems. This period also saw the maturation of graduate engineering education and the rise of large-scale research and development organized on the national level. So far the physical sciences – physics and chemistry – have contributed most to technology. They will continue to contribute, for instance in the emerging nanotechnology that will take over the torch of the microelectronics revolution. Increasingly, they are joined by biology, which has been transformed by the spectacular success of molecular and genetic biology. Biotechnology is a multidisciplinary field, drawing knowledge from biology, biochemistry, physics, information processing and various engineering expertise. The cooperation and convergence of traditional intellectual disciplines in the development of new technology is the trend of the future.
The crucial and unique task of the engineer is to identify, understand, and integrate the constraints on a design in order to produce a successful result. It is usually not enough to design a technically feasible product or process; it must also meet further requirements. Constraints may include available resources, physical or technical limitations, flexibility for future modifications and additions, and other factors, such as requirements for cost, marketability, producibility, and serviceability. By understanding the constraints, engineers derive specifications for the limits within which a viable object or system may be produced and operated.
Engineers use their knowledge of science, mathematics, and appropriate experience to find suitable solutions to a problem. Creating an appropriate mathematical model of a problem allows them to analyze it (sometimes definitively), and to test potential solutions. Usually multiple reasonable solutions exist, so engineers must evaluate the different design choices on their merits and choose the solution that best meets their requirements. Genrich Altshuller, after gathering statistics on a large number of patents, suggested that compromises are at the heart of "low-level" engineering designs, while at a higher level the best design is one which eliminates the core contradiction causing the problem.
Engineers typically attempt to predict how well their designs will perform to their specifications prior to full-scale production. They use, among other things: prototypes, scale models, simulations, destructive tests, nondestructive tests, and stress tests. Testing ensures that products will perform as expected. Engineers as professionals take seriously their responsibility to produce designs that will perform as expected and will not cause unintended harm to the public at large. Engineers typically include a factor of safety in their designs to reduce the risk of unexpected failure. However, the greater the safety factor, the less efficient the design may be.
As with all modern scientific and technological endeavours, computers and software play an increasingly important role. Numerical methods and simulations can help predict design performance more accurately than previous approximations.
Using computer-aided design (CAD) software, engineers are able to more easily create drawings and models of their designs. Computer models of designs can be checked for flaws without having to make expensive and time-consuming prototypes. The computer can automatically translate some models to instructions suitable for automatic machinery (e.g., CNC) to fabricate (part of) a design. The computer also allows increased reuse of previously developed designs, by presenting an engineer with a library of predefined parts ready to be used in designs. Computers can also be used as part of the manufacturing process, controlling the machines and ensuring a constant level of quality and similarity in the products. This process is Computer Aided Manufacture (CAM) and works in a similar way to CNC but where CNC controls the machinery, CAM controls the whole manufacture process from cutting to assembly.
Of late, the use of finite element method analysis (FEM analysis or FEA) software to study stress, temperature, flow as well as electromagnetic fields has gained importance. In addition, a variety of software is available to analyse dynamic systems. The FEM method is in contrast to the older (but still useful) finite difference (FD) method. In that approach, the continuous system is represented by variables on predefined gridpoints. In the case of large deformations the FD grid cannot easily be extended in space so as to accommodate the motions; in the appearance of abrupt transitions, the grid may have to be refined (subdivided) in the region of rapid change. The FEM largely avoids those problems by having the grid tied to the material.
Electronics engineers make use of a variety of circuit schematics software to aid in the creation of circuit designs that perform an electronic task when used for a printed circuit board (PCB) or a computer chip.
The application of computers in the area of engineering of goods is known as Product Lifecycle Management (PLM).
Engineering is a subject that ranges from large collaborations to small individual projects. Almost all engineering projects are beholden to some sort of financing agency: a company, a set of investors, or a government. The result of this is that large-scale engineering projects often lose much of their original purpose to some form of bureaucracy. The few types of engineering that are minimally constrained by such issues are pro bono engineering and open design engineering.
Engineering is a well respected profession. For example, in Canada it ranks as one of the public's most trusted professions.
Sometimes engineering has been seen as a somewhat dry, uninteresting field in popular culture, and has also been thought to be the domain of nerds. For example, the cartoon character Dilbert is an engineer.
This has not always been so - most British school children in the 1950s were brought up with stirring tales of 'the Victorian Engineers', chief amongst whom where the Brunels, the Stephensons, Telford and their contemporaries.
In science fiction engineers are often portrayed as highly knowledgeable and respectable individuals who understand the overwhelming future technologies often portrayed in the genre. The Star Trek characters Montgomery Scott and Geordi La Forge are famous examples.
Engineers are often respected and ridiculed for their intense beliefs and interests. Perhaps because of their deep understanding of the interconnectedness of many things, engineers such as Governor John H. Sununu, New York City Mayor Michael Bloomberg and Nuclear Physicist Edward Teller, are often driven into politics to "fix things" for the public good.
Occasionally, engineers may be recognized by the "Iron Ring"--a stainless steel or iron ring worn on the little (fourth) finger of the dominant hand. This tradition was originally developed in Canada in the Ritual of the Calling of an Engineer as a symbol of pride and obligation for the engineering profession. Some years later this practice was adopted in the United States. Members of the US Order of the Engineer accept this ring as a pledge to uphold the proud history of engineering. A Professional Engineer's name often has the post-nominal letters PE or P.Eng.
While it appears Engineers still only need a bachelor's degree to obtain a lucrative position that receives respect from the public, in fact it is only through a life-time devotion to their field and the further advancement of their own technical knowledge that they might arrive at such a destination.
Laws protecting public health and safety mandate that a professional must provide guidance gained through education and experience. In the United States, each state tests and licenses Professional Engineers.
The federal government, however, supervises aviation through the Federal Aviation Regulations administrated by the Dept. of Transportation, Federal Aviation Administration. Designated Engineering Representatives approve data for aircraft design and repairs on behalf of the Federal Aviation Administration.
Even with strict testing and licensure, engineering disasters still occur. Therefore, the Professional Engineer or Chartered Engineer adheres to a strict code of ethics. Each engineering discipline and professional society maintains a code of ethics, which the members pledge to uphold.
In Canada the profession in each province is governed by its own engineering association. For instance, in the Province of British Columbia an engineering graduate with 5 or more years of experience in an engineering-related field will need to be certified by the Association for Professional Engineers and Geoscientists (APEGBC) in order to become a Professional Engineer.
Refer also to the Washington accord for international accreditation details of professional engineering degrees.
Comparison to other disciplines
- You see things; and you say "Why?" But I dream things that never were; and I say "Why not?" —George Bernard Shaw
- Scientists study the world as it is; Engineers create the world that has never been. —Theodore von Karman
Engineering is concerned with the design of a solution to a practical problem. A scientist may ask why a problem arises, and proceed to research the answer to the question or actually solve the problem in his first try, perhaps creating a mathematical model of his observations. By contrast, engineers want to know how to solve a problem, and how to implement that solution. In other words, scientists attempt to explain phenomena, whereas engineers use any available knowledge, including that produced by science, to construct solutions to problems.
There is an overlap between science (fundamental and applied) and engineering. It is not uncommon for scientists to become involved in the practical application of their discoveries; thereby becoming, for the moment, engineers. Scientists may also have to complete engineering tasks, such as designing experimental apparatus or building prototypes. Conversely, in the process of developing technology engineers sometimes find themselves exploring new phenomena, thus becoming, for the moment, scientists.
However, engineering research has a character different from that of scientific research. First, it often deals with areas in which the basic physics and/or chemistry are well understood, but the problems themselves are too complex to solve in an exact manner. The purpose of engineering research is then to find approximations to the problem that can be solved. Examples are the use of numerical approximations to the Navier-Stokes equations to solve aerodynamic flow over an aircraft, or the use of Miner's rule to calculate fatigue damage . Second, engineering research employs many semi-empirical methods that are foreign to pure scientific research, one example being the method of parameter variation.
In general, it can be stated that a scientist builds in order to learn, but an engineer learns in order to build.
There are significant parallels between engineering and medicine. Both fields are well known for their pragmatism — the solution to real world problems often requires moving forward before phenomena are completely understood in a more rigorous scientific sense and therefore experimentation and empirical knowledge is an integral part of both. Part of medicine examines the function of the human body. The human body although biological has many functions similar to a machine. The heart for example functions much like a pump, the skeleton is like a linked structure with levers etc. This similarity has led to the development of the field of biomedical engineering that utilizes concepts developed in both disciplines.
There are also close connections between the workings of engineers and artists; they are direct in some fields, for example, architecture, landscape architecture and industrial design (even to the extent that these disciplines may sometimes be included in a University's Faculty of Engineering); and indirect in others. Artistic and engineering creativity may be fundamentally connected as the case of Leonardo Da Vinci indicates.
In Political science the term engineering has been borrowed for the study of the subjects of Social engineering and Political engineering that deal with forming political and social structures using engineering methodology coupled with political science principles.
The various branches (or disciplines) of engineering include: