Agricultural Mechanization

The mechanization of agriculture began in the mid-19th century, but the most profound advances and applications have occurred during the 20th century. Mechanized equipment has almost entirely replaced human and animal power for farming tasks in developed nations, and it is now transforming agriculture in many developing areas as well. Such equipment, from tractors and cultivators to a wide variety of harvesting machinery, has enabled an explosion in agricultural productivity for both food and fibers during the 20th century. In the process, however, agricultural mechanization also promoted a massive shift from rural to urban life in the developed countries, along with similarly massive changes in the nature of work, the consumer economy, women's roles in society, and even the size and nature of families.

Air Conditioning and Refrigeration

Air conditioning enabled a redefinition of the standards of human comfort during the 20th century, but along with the closely related field of refrigeration, it also made possible numerous manufacturing, food processing and storage, and medical processes. Air conditioning became a practical endeavor only after Willis Carrier fully defined the relationships between air, water, and energy in his "psychrometric chart," and after the development of new, effective refrigerants in this century. Air conditioning of homes, offices, stores, and vehicles made many naturally hot regions attractive to millions of people and sparked huge demographic changes. Moisture control enables a number of moisture-sensitive manufacturing processes, and refrigeration enhances the preservation of food, medical tissues, and a wide variety of perishable items. Few technologies have had greater direct effect on human comfort and lifestyle during this century.  

It's a Cool Story: Refrigeration and Air Conditioning in the 20th Century, ME May 2000, by Bernard Nagengast

Airplane

Truly a product of 20th century technology, the airplane has had a vast impact on the domestic and international scene by reducing travel times over long distances. The airplane enabled a redefinition of the concept of travel, since the route and speed limitations of land and sea did not apply. The airplane also redefined the relationship between the travelling public and the engineers who designed and built the planes, as travelers entrusted their lives to engineers' products as never before. As a result, more people have been able to travel farther than most would have ever dreamed, and the entire world has become accessible. This century has witnessed a steady improvement in aircraft performance, safety, and efficiency as engineers have continued to refine the airplane and its supporting systems.  

The Mechanics of Flight, ME July 2000, by J. Lawrence Lee
First Flights, ME July 2000, by Frank Wicks

Apollo

Project Apollo produced the first--and so far only--vehicles for humans to visit another heavenly body, an achievement that must be seen as one of the outstanding accomplishments in all of human history. The "earthrise" viewed from Apollo 8 forever reshaped our view of the Earth as a fragile outpost for life in the vastness of space, and the samples from the six lunar-landing missions continue to provide evidence for a better understanding of our universe. From the Saturn V booster to the lunar module, Apollo was an engineering triumph. The knowledge gained in power, structures, life support, and materials continues to benefit humankind, and Apollo's success continues to inspire new visions for exploration.

Automobile

Although invented in the late 1800s, the automobile did not come into prominence until the early 20th century, after its basic configuration was determined and mass-production methods were established to make it available to a broad cross section of society. Few, if any, other machines have been as widely adopted or used as an agent of change in so many societal institutions and practices. The automobile vastly expanded most people's mobility horizons, and it enabled profound changes in most aspects of modern life, from courting practices to work practices; from housing options to leisure-time options; and from small shops to large factories. Even the relationship of citizens and their government adapted to embrace a new model for public works as publicly funded roads were built to support the automobile. With the good has also come the bad, including air pollution and accidents, but even these have heightened our awareness of the value of human life and fostered new engineering solutions to improve the quality of the human condition.

Bioengineering

Another creation of the 20th century, the field of bioengineering has enabled major advances in the understanding of life and produced numerous machines to sustain, prolong, and enhance human life. The heart-lung machine made heart surgery, and ultimately transplants, possible, while artificial hearts keep patients alive until suitable donors can be found. Numerous other machines enable a wide variety of diagnostic and surgical procedures that were undreamed of in the first half of this century, including the high-speed dental drill, the infant incubator, and nuclear magnetic resonator. Replacement joints provide unprecedented relief to those suffering from severe joint deterioration. Recent advancements in electronics and electro-mechanical actuators hold out promise for mobility to many in the foreseeable future. In no other field has engineering and technology become so intimately wedded to life itself.  

Life Force, ME March 2000, by Sohi Rastegar

Bottle Manufacturing

Only since 1912 have automated bottle-making machines introduced a cheap and plentiful supply of glass containers for pharmaceuticals, household products, food and beverages, and an endless variety of uses. Safety, standardization, quality, and convenience of glass containers not only revolutionized the industry, these machines ended child labor in glass-container plants. In 1913, the National Child Labor Committee of New York City said the rapid introduction of the automatic machine did more to eliminate child labor than they had been able to do through legislation.

Codes and Standards

Safety is the paramount consideration for all engineers. As machinery grew larger, more complex, and ubiquitous in modern life, it became essential to establish standards for the safe construction and operation of a wide array of devices and systems. The ASME Boiler Code of 1914 marked the first time that manufacturers agreed on a set of specifications to ensure against failures and enhance public safety. This effort grew to include all manner of devices and systems with a potential for injurious failure, including pressure vessels, cranes, elevators, and nuclear reactors--with many of its provisions codified into laws and regulations. Unknown and unappreciated by the public, codes and standards have nevertheless proven to be an unsurpassed agent for public safety and welfare.  

Setting the Standards, ME Feb 2000, by Walter Leight and Belinda Collins

Food Processing

Nothing is more important to life than safe food, and engineers have contributed more to this cause during the 20th century than in all previous ones combined. Louis Pasteur discovered the basis for sterilization in 1881, but bulk sterilization of canned food began about 1920, ushering in a new age of safe and economical food processing and distribution. Thanks to the efforts of many engineers, food processing is now a highly mechanized industry that furnishes a tremendous quantity and variety of safe, nutritious food to the world.

Glass Manufacturing

The 20th century brought a level of perfection to glass manufacture that reaches into every home and business structure in the world, from the perfectly smooth surface of float plate glass for windows to fiberglass used for thermal insulation of industrial buildings and homes, as acoustic insulation, for fireproofing, as a reinforcing material in plastics, cement, and textiles, in automotive components, in gaskets and seals, and in filters for air and fluids. Formed by laying molten glass on liquid metal surfaces, the float plate glass manufacturing became of integral part of modern or Bauhaus structures and products. Refinements in fiberglass have led, however, to the same concerns resulting from asbestos fibers. (Glass wool is now considered a carcinogenic, thus making fiberglass one of the greater engineering challenges of the next century.) Glass bottles were made by hand at the turn of the 20th century, and by the mid-1920s ,80 percent were machine-made. Even the first succcessful fully automated machine for form light bulbs was only introduced in 1926.

Integrated Circuit Mass Production

Like the automobile and the light bulb, the world's first practical production machine for the assembly of integrated circuits made possible their economical production and thus the integrated circuit a reality. The ABACUS II, designed and built by Texas Instruments, was the first practical automated production machine for the assembly of integrated circuits. Using heat and pressure, it bonded fine gold wire to microscopic contacts on the silicon chip and pin connections on the package, with a positioning accuracy of ? 0.00025 inch while bonding up to 375 devices an hour.

Numerically Controlled Machines and Robotics

Of the many ways that computers have impacted human life during the last half of the 20th century, few have had greater effect on society than the automatic control of machines. Whether the product is a convenience like automotive cruise control or a major redefinition of a societal institution such as numerically controlled machining and robotic assembly of complex devices, "NC" machines have enabled direct and indirect changes in almost every aspect of modern life. By redefining--physically and economically--our concepts of work and the nature of human involvement in numerous activities, they are encouraging people to focus on the most creative aspects of life instead of the more mundane ones.

Paper Converting

From public health cries for sanitary solutions, through the excesses of a disposable society, to visions of the paperless society, the saga of paper conversion has been a major story for the 20th century. The paper cup was inspired by public health concerns, particularly the sharing of the community dipper. Disposable diapers, sanitary products, food service items, food packaging, and the grocery bag are prominent examples of the innovative design opportunities. With this industry, however, comes the environmental challenges of and subsequent engineering solutions to landfill options.

Plastic Manufacturing

Mass production of plastics, beginning with the Bakelite process, offered 20th-century mass production a lighter, extremely flexible material for most product design. Examples include extrusion molding (weather strippings, wire insulation, plastic tubing, and clothing fibers like Nylon), blow molding (bottles and thin-walled glasses), sheet casting (Mylar and Saranwrap), and injection molding (parts for everything, including dashboards, appliance cases, floppy diskette cases).

Power Generation

Electrification has improved the lives of people around the world in countless ways. It is by far the most flexible power-transmission method yet devised, but before it can be transmitted and used, electricity must first be generated. A wide variety of energy sources, including water, wind, fossil fuels, and nuclear, can be used to turn the generators that produce an electric current, but the growth in size, efficiency, safety, and reliability of the generating machinery is rarely appreciated by the public. Indeed, an uninterrupted supply of electricity is now considered as the norm, and the interruptions that do occur are rarely the fault of machinery at the generating stations. The wide availability of electric power to perform thousands of essential and enjoyable functions has been a primary shaping element of the 20th century, and power generation, whether it involves hydropower, steam, internal-combustion, nuclear, or a host of alternate prime movers, continues to provide the energy our modern society requires.

Ribbon Machine

The incandescent electric light revolutionized nightlife around the world, but the ubiquitous light bulb could not have succeeded without an efficient, economical method of manufacturing the billions of glass envelopes, or "bulbs" required over the years. In 1925, when the best semi-automated methods could produce less than 300 bulbs per hour, Will Woods of the Corning Glass Works introduced his ribbon machine that streamlined the process and increased production five-fold. Within five years, a single ribbon machine could produce around 2,000 bulbs per minute, lowering the cost of the bulb to less than one cent. The ribbon-machine has changed little since its introduction. Fewer than 15 machines now produce the world's entire supply of standard bulbs, making the unsung ribbon machine one of the most effective industrial machines ever, and making a vast range of nighttime activities possible.

Xerography

During the 1960s, one observer of technology asked, "What hath Xerox wrought?" (an obvious play on the words of Samuel Morse's first telegraph message over a century earlier). That the question was asked at all--less than 20 years after the first Xerox copier was sold--reveals how ubiquitous the electrostatic copying process known as Xerography had become, as well as its potential for reshaping communication, at least communication on paper. No technology since the Linotype and high-speed printing (in the 1880s) had made printed matter so universally available, and no information technology so decentralized the control over the intellectual content of those documents, including the tremendous impact of paperback printing. By making small- and moderate-run reproduction economical and easy for anyone to do, Xerography permitted a wider dissemination of ideas than ever before. Today, communication options steadily increase as engineers continue to incorporate the basic technology into other devices, such as laser printers.