Creating the Twentieth Century

by Vaclav Smil

  In technical terms there are two saltation periods of human history that stand apart as the times of the two most astounding, broad, and rapid innovation spurts. The first one, purely oriental, took place during the Han dynasty China (207 B.C.E.–9 C.E.); the second one, entirely occidental in both its genesis and its nearly instant flourish, unfolded in Europe and North America during the two generations preceding WWI. In both instances, those widespread and truly revolutionary innovations not only changed the course of the innovating societies but also were eventually translated into profound global impacts. The concatenation of Han advances laid strong technical foundations for the development of the world’s most persistent empire—which was, until the 18th century, also the world’s richest economy—and for higher agricultural and manufacturing productivities far beyond its borders (Needham et al. 1965, 1971; Temple 1986).

  The dynasty’s most important innovations were in devising new mechanical devices, tools, and machines and advancing the art of metallurgy. The most remarkable new artifacts included the breast-band harness for horses and prototypes of efficient collar harnesses, wooden moldboard ploughs with curved shares made from nonbrittle iron, multitube seed drills, cranks, rotary winnowing fans, wheelbarrows, and percussion drills (figure 1.2). Metallurgical innovations included the use of coal in ironmaking, production of liquid iron, decarburization of iron to make steel, and casting of iron into interchangeable molds. But this innovative period was spread over two centuries, and some of its products were not adopted by the rest of the Old World for centuries, or even for more than a millennium after their initial introduction in China (Smil 1994).

  The Unprecedented Saltation

  In contrast, the impact of the late 19th and the early 20th century advances was almost instantaneous, as their commercial adoption and widespread diffusion were very rapid. Analogy with logic gates in modern computers captures the importance of these events. Logic gates are fundamental building blocks of digital circuits that receive binary inputs (0 or 1) and produce outputs only if a specified combination of inputs takes place. A great deal of potentially very useful scientific input that could be used to open some remarkable innovation gates was accumulating during the first half of the 19th century. But it was only after the mid-1860s when so many input parameters began to come together that a flood of new instructions surged through Western society and our civilization ended up with a very different program to guide its future.

  FIGURE 1.2. Sichuanese salt well made with a percussion drill, one of the great inventions of the Han dynasty in China. The same technique was used to drill the first U.S. oil well in Pennsylvania in 1859. Reproduced from a Qing addition to Song’s (1673) survey of China’s techniques.

  The most apposite evolutionary analogy of this great technical discontinuity is the Cambrian eruption of highly organized and highly diversified terrestrial life. This great evolutionary saltation began about 533 million years ago and produced—within a geologically short spell of just 5–10 million years, or less than 0.3% of the evolutionary span—virtually all of the animal lineages that are known today (McMenamin and McMenamin 1990; Bowring et al. 1993). Many pre-WWI innovations were patented, commercialized, and ready to be diffused in just a matter of months (telephone, lightbulbs) or a few years (gasoline-fueled cars, synthesis of ammonia) after their conceptualization or experimental demonstration. And as they were built on fundamental scientific principles, it is not only their basic operating modes that have remained intact but also many specific features of their pioneering designs are still very much recognizable among their most modern upgrades.

  The era’s second key attribute is the extraordinary concatenation of a large number of scientific and technical advances. The first category of these scientific advances embraces those fundamentally new insights that made it possible to introduce entirely new industries, processes, and products. Certainly the most famous example of this kind is a fundamental extension of the first law of thermodynamics that was formulated by Albert Einstein as a follow-up of his famous relativity paper: “An inertial mass is equivalent with an energy content Μc2” (Einstein 1907). By 1943 this insight was converted into the first sustained fission reaction; 1945 saw the explosions of the first three fission bombs (Ala-mogordo, Hiroshima, Nagasaki), and by 1956 the first commercial fission reactor began generating electricity (Smil 2003).

  But during the 20th century everyday lives of hundreds of millions of people were much more affected by Heinrich Hertz’s discovery of electromagnetic waves much longer than light but much shorter than sound. This adventure started in 1886 with detecting the spark-generated waves just across a lecture room in Karlsruhe. Soon the reach progressed to Marconi’s Morse signals on land, between ships, and across the Atlantic, then to Fessenden’s pioneering radio broadcasts and, after WWI, to television—and to much more. By the year 2000 the Hertzian waves made possible such wonders as finding one’s place on the planet with global positioning systems or alerting the owners of colorful Nokia phones to the arrival of new messages by chirping operatic tunes—be it in Hong Kong’s packed subways or on mountain peaks in the Alps.

  And then there were new scientific insights that did not launch new products or entirely new industries but whose broad theoretical reach has been helpful in understanding a variety of everyday challenges and has been used to construct better devices and more efficient machines. An outstanding example was the realization that a ratio calculated by multiplying characteristic distance and velocity of a moving fluid by its density and dividing that product by the fluid’s viscosity yields a dimensionless number whose magnitude provides fundamental information about the nature of the flow. Osborne Reynolds (1842–1912), a priest in the Anglican Church and the first professor of engineer in Manchester, found this relationship in 1883 after experiments with water flowing through glass tubes (Rott 1990).

  Low Reynolds numbers correspond to smooth laminar flow that is desirable in all pipes as well as along the surfaces of ships or airplanes. Turbulence sets in with higher Reynolds numbers, and completely turbulent flows are responsible for cavitation of ship propellers (chapter 2 tells how Charles Parsons solved this very challenge), vibration of structures, erosion of materials, and relentless noise. A great deal of the roar you hear when sitting in the aft section of a jet airplane does not come from the powerful gas turbines but from the air’s turbulent boundary layer that keeps pounding the plane’s aluminum alloy skin. Preventing cavitation, vibration, erosion, and noise and operating with optimized Reynolds numbers brings many great rewards.

  The period’s fundamental technical advances include, above all, large-scale electricity generation and transmission and the inventions of new prime movers and energy converters. Internal combustion engines and electric motors have eventually become the world’s most common mechanical prime movers. Transformers and rectifiers ensure the most efficient use of electricity in energizing many specialized assemblies and machines whose sizes range from microscopic (components of integrated circuits) to gargantuan (enormous excavators and construction cranes), from stationary designs (in manufacturing, commerce, and households) to the world’s fastest trains. Yet another group of technical advances includes production processes whose commercialization put on the market new, or greatly improved, products or procedures whose use in turn boosted other technical capabilities and transformed economic productivities and private consumption alike.

  By far the most important new materials were inexpensive high-quality steels and aluminum produced electrolytically by Hall-Héroult process. Henry Ford’s moving assembly line and the liquefaction of air are excellent examples of new processes whose adoption changed the nature of industrial production. The last process is also a perfect illustration of how ubiquitous and indispensable are the synergies of these inventions. Less than two decades after its discovery, the liquefaction of air found one of its most massive (and entirely unanticipated) uses as the supplier of nitrogen for the Haber-Bosch synthesis of ammonia.
High crop yields and deep greens of suburban lawns are thus linked directly to air liquefaction through nitrogen fertilizers. And, most remarkably, in many cases the ingredients necessary for completely new systems fell almost magically in place just as they were needed. The most notable concatenation brought together incandescing filaments, efficient dynamos and transformers, powerful steam turbines, versatile polyphase motors, and reliable cables and wires for long-distance transmission to launch the electric era during a mere dozen or so years.

  The third remarkable attribute of the pre-WWI era is the rate with which all kinds of innovations were promptly improved after their introduction—made more efficient, more convenient to use, less expensive, and hence available on truly mass scales. For example, as I detail in chapter 2, efficiency of incandescent lights rose more than six-fold between 1882 and 1912 while their durability was extended from a few hundred to more than 1,000 hours. There were similarly impressive early gains in the efficiency of steam turbines and electricity consumption in aluminum electrolysis.

  The fourth notable characteristic of the great pre-WWI technical discontinuity is the imagination and boldness of new proposals. There is no better testimony to the remarkable pioneering spirit of the era than the fact that so many of its inventors were eager to bring to life practical applications of devices and processes that seemed utterly impractical, even impossible, to so many of their contemporaries. Three notable examples illustrate these attitudes of widely shared disbelief. On March 29, 1879, just nine months before Thomas Edison demonstrated the world’s first electrical lighting system, American Register concluded that “it is doubtful if electricity will ever be used where economy is an object” (cited in Ffrench 1934:586). The same year, the Select Committee on Lighting by Electricity of the British House of Commons heard an expert testimony that there is not “the slightest chance” that electricity could be “competing, in general way, with gas,” and The Engineer wrote on November 9, 1877, that “electricity for domestic illumination would never, in our view, prove as handy as gas. An electric light would always require to keep in order a degree of skilled attention which few individuals would possess” (quoted in Beauchamp 1997:136). Henry Ford reminisced that the Edison Company objected to his experiments with internal combustion and that its executives offered to hire him “only on the condition that I would give up my gas engine and devote myself to something really useful” (Ford 1922:34). And three years before the Wright brothers took off above the dunes at Kitty Hawk in North Carolina on December 17, 1903 (figure 1.3), Rear Admiral George W. Melville (1901) concluded that “outside of the proven impossible, there probably could be found no better example of the speculative tendency carrying man to the verge of chimerical than in his attempts to imitate the birds” (p. 825).

  FIGURE 1.3. Orville Wright is piloting while Wilbur Wright is running alongside as their machine lifts off briefly above the sands of the Kitty Hawk, North Carolina, at 10:35 a.m. on December 17, 1903. Library of Congress image (LC-W86-35) is reproduced from the Wrights’ glass negative.

  Finally, there is the epoch-making nature of these technical advances, the proximate reason for writing this book: most of them are still with us not just as inconsequential survivors or marginal accoutrements from a bygone age but as the very foundations of modern civilization. Such a profound and abrupt discontinuity with such lasting consequences has no equivalent in history. The closest analogy in the more recent human prehistory was obviously the emergence of the first settled agricultural societies nearly 10,000 years ago. But the commonly used term of Agricultural Revolution is a misnomer for that gradual process during which foraging continued to coexist first with incipient and then with slowly intensifying cultivation (Smil 1994). In contrast, the pre-WWI innovations tumbled in at a frenzied pace.

  When seen from the vantage point of the early 21st century, there is no doubt that the two generations between the late 1860s and the beginning of WWI remain the greatest technical watershed in human history. Moreover, as stressed at the outset, this was the first advance in nearly 4.5 billion years of the planet’s evolution that led to the generation of cosmically detectable signals of intelligent life on Earth: a new civilization was born, one based on synergy of scientific advances, technical innovation, aggressive commercialization, and intensifying, and increasingly efficient, conversions of energy.

  The Knowledge Economy

  Technical advances of the antiquity, Middle Ages, and the early modern era had no scientific foundation. They had to be based on observations, insights, and experiments, but they were not guided by any coherent set of accumulated understanding that could at least begin to explain why some devices and processes work while others fail. They involved an indiscriminate pursuit of ideas that opened both promising paths of gradual improvements, be it of water-wheels or sails, as well as cul-de-sacs of lapis philosophorum or perpetuum mobile. Even the innovations of the early decades of the Industrial Revolution conformed to this pattern. Writing at the very beginning of the 19th century, Joseph Black noted that “chemistry is not yet a science. We are very far from the knowledge of first principles. We should avoid everything that has the pretensions of a full system” (Black 1803:547). Mokyr’s (1999) apt characterization is that the first Industrial Revolution created a chemical industry without chemistry, an iron industry without metallurgy, and power machinery without thermodynamics.

  In contrast, most of the technical advances that appeared during the two pre-WWI generations had their basis in increasingly sophisticated scientific understanding, and for the first time in history, their success was shaped by close links and rapid feedbacks between research and commercialization. Naturally, other innovations that emerged during that period had still owed little to science as they resulted from random experimenting or serendipity. This is not surprising as we have to keep in mind that the new process of scientifically based technical developments was unfolding along the underlying trend of traditionally incremental improvements.

  The first foundations of new knowledge economy appeared during the 17th century, their construction accelerated during the 18th century, and the process matured in many ways before 1870. Its genesis, progress, grand features, and many fascinating details are best presented by Mokyr (2002). Here I will illustrate these changes by a few examples describing the evolution of prime movers that I have studied in some detail (Smil 1991, 1994). Prime movers are those energy converters whose capacities and efficiencies determine the productive abilities of societies as well as their tempo of life; they are also critical for energizing chemical syntheses whose accomplishments help to form our surroundings as well as to expand the opportunities for feeding and healing ourselves.

  At the beginning of the 18th century, both the dominant and the largest prime movers were the same ones as in the late antiquity. Muscles continued to be the most common prime movers: humans could sustain work at rates of just between 50 and 90 W, while draft mammals could deliver no more than 300 W for small cattle, 400–600 W for smaller horses, and up to 800 W for heavy animals. Capacity of European waterwheels, the most powerful prime movers of the early modern era, averaged less than 4 kW. This means that it took until 1700 to boost the peak prime mover ratings roughly 40-fold (figure 1.4), and there was no body of knowledge to understand the conversion of food and feed into mechanical energy and to gauge the efficiency of this transformation.

  By 1800 there was still no appreciation of thermal cycles, no coherent concept of energy, no science of thermodynamics, no understanding of metabolism. Antoine Lavoisier’s (1743–1794) suggestion of the equivalence between heat output of animals and men and their feed and food intake was only the first step on a long road of subsequent studies of heterotrophic metabolism. But there was important practical progress as James Watt (1736–1819) converted Newcomen’s steam engine from a machine of limited usefulness and very low efficiency to a much more practical device capable of about 20 kW that began revolutionizing many tasks in coal mining, metallurgy,
and manufacturing (Thurston 1878; Dalby 1920). Watt also invented a miniature recording steam gauge, and this indicator made it possible to study the phases of engine cycles.

  By 1870 thermodynamics was becoming a mature science whose accomplishments helped to build better prime movers and to design better industrial processes. This transformation started during the 1820s with Sadi Carnot’s (1796–1832) formulation of essential principles that he intended to be applicable to all imaginable heat engines (Carnot 1824). This was a bold claim but one that was fully justified: thermodynamic studies soon confirmed that no heat engine can be more efficient than a reversible one working between two fixed temperature limits and that the highest theoretical efficiency of this Car-not cycle cannot surpass 65.32%. Another important insight published during the 1820s was Georg Simon Ohm’s (1789–1854) explanation of electricity conduction in circuits and the formulation of what later became the eponymous law relating current, potential, and resistance (Ohm 1827). Correct understanding of this relationship was a key to devising a commercially affordable system of electric lighting as it minimized the mass of expensive conductors.

  FIGURE 1.4. Maximum power of prime movers, 1000 B.C.E. to 1700 C.E. Waterwheels became the most powerful inanimate prime movers of the pre-industrial era and lost this primacy to steam engines after 1730.