Childbed fever, also known as puerperal fever, is a form of bacteria-caused sepsis informally referred to as blood poisoning. Semmelweis also noticed that puerperal fever was rare among women who gave birth in the streets, and he surmised that infectious substances (e.g., particles of some kind) were being passed from cadavers to the women. After instructing hospital staff to always wash their hands in a chlorinated disinfecting solution before treating women, the number of deaths plummeted dramatically.
Alas, despite his amazing results, many of the physicians of the time did not accept his findings, perhaps in part because this would have been admitting that they were the unwitting cause of so much death. Additionally, many physicians of the time blamed such diseases on miasma, a kind of toxic atmosphere. In the end, Semmelweis went mad and was involuntarily confined to an insane asylum, where he was beaten to death by guards. After his death, however, he was vindicated by the germ studies of French microbiologist Louis Pasteur and innovations in antiseptic surgery by British surgeon Joseph Lister.
SEE ALSO Sewage Systems (c. 600 BCE) Germ Theory of Disease (1862), Antiseptics (1865).
Today, when surgeons scrub their hands before an operation, it is common to use a sterile brush, chlorhexidine or iodine wash, and a tap that can be turned on and off without hand intervention.
1850
Second Law of Thermodynamics • Clifford A. Pickover
Rudolf Clausius (1822–1888), Ludwig Boltzmann (1844–1906)
Whenever I see my sand castles on the beach fall apart, I think of the Second Law of Thermodynamics (SLT). The SLT, in one of its early formulations, states that the total entropy, or disorder, of an isolated system tends to increase as it approaches a maximum value. For a closed thermodynamic system, entropy can be thought of as a measure of the amount of thermal energy unavailable to do work. German physicist Rudolf Clausius stated the First and Second Laws of Thermodynamics in the following form: The energy of the universe is constant, and the entropy of the universe tends to a maximum.
Thermodynamics is the study of heat, and more generally the study of transformations of energy. The SLT implies that all energy in the universe tends to evolve toward a state of uniform distribution. We also indirectly invoke the SLT when we consider that a house, body, or car—without maintenance—deteriorates over time. Or, as novelist William Somerset Maugham wrote, “It’s no use crying over spilt milk, because all of the forces of the universe were bent on spilling it.”
Early in his career, Clausius stated, “Heat does not transfer spontaneously from a cool body to a hotter body.” Austrian physicist Ludwig Boltzmann expanded upon the definition for entropy and the SLT when he interpreted entropy as a measure of the disorder of a system due to the thermal motion of molecules.
From another perspective, the SLT says that two adjacent systems in contact with each other tend to equalize their temperatures, pressures, and densities. For example, when a hot piece of metal is lowered into a tank of cool water, the metal cools and the water warms until each is at the same temperature. An isolated system that is finally at equilibrium can do no useful work without energy applied from outside the system, which helps explain how the SLT prevents us from building many classes of Perpetual Motion Machines.
SEE ALSO Boltzmann’s Entropy Equation (1875), Carnot Engine (1824), Conservation of Energy (1834).
LEFT: Rudolph Clausius. RIGHT: Microbes build their “improbable structures” from ambient disordered materials, but they do this at the expense of increasing the entropy around them. The overall entropy of closed systems increases, but the entropy of individual components of a closed system may decrease.
1855
Bessemer Process • Marshall Brain
Henry Bessemer (1813–1898)
In the Iron Age, the prevalent use of iron implements changed the world. However, an equally revolutionary shift occurred after English engineer Henry Bessemer developed a process to refine iron and produce steel commercially, first patented in 1855.
Where does steel come from? Start with iron. Dig iron ore out of the ground and transform it into iron in a blast furnace. It comes out as pig iron with a carbon content of 5 percent or so. Put pig iron into a basic oxygen furnace to form steel. Pure oxygen blasts in under pressure and burns off much of the carbon, leaving behind 0.1 percent carbon (mild steel) to 1.25 percent carbon (high-carbon steel). The carbon content, plus any alloying metals, plus the quenching process, determine the properties of the steel in use.
Steel is a remarkable material: dependably strong and resistant to fatigue, it is also workable and highly mutable—it can take a number of different forms. For example, if you heat up steel and quench (cool) it one way, it is more ductile. Quench it another way and it is much harder and more brittle. It is even possible to get both effects at the same time with case hardening. The outer shell is hard and therefore difficult to cut, while the interior is softer to combat the brittleness.
Then there are the alloys. Add a little chromium to steel and it won’t rust. Add extra carbon and it becomes much harder. Add tungsten or molybdenum and you get tool steels. Add vanadium and it holds up better to wear.
This combination of advantages explains why steel is so ubiquitous. Engineers use steel in car bodies and engines because of the combination of strength, cost, and durability. Engineers use steel in skyscrapers such as Burj Khalifa for the same reasons. Big bridges such as the Millau Viaduct, same thing. They reinforce concrete with steel to greatly improve its strength in tension. One place where steel isn’t found is where weight is a factor—aluminum or carbon fiber is used there. Or where strength and durability isn’t a big factor and cost is—plastic is used there.
SEE ALSO Iron Smelting (c. 1300 BCE), Roman Concrete (c. 126), Plastic (1856)
White-hot steel pours like water from a 35-ton electric furnace, Allegheny Ludlum Steel Corp., Brackenridge, PA, circa 1941.
1855
Cell Division • Clifford A. Pickover
Matthias Jakob Schleiden (1804–1881), Theodor Schwann (1810–1882), Rudolf Ludwig Karl Virchow (1821–1902)
Based on his observations and theories, German physician Rudolf Virchow emphasized that diseases could be studied not only by observing a patient’s symptoms but by realizing that all pathology (disease diagnosis) is ultimately a study of cells. Rather than focusing on the entire body, he helped to launch the field of cellular pathology by considering that certain cells or groups of cells can become sick.
In 1855, he popularized the famous aphorism omnis cellula e cellula, which means that every cell derives from a preexisting cell. This suggestion was a rejection of the theory of spontaneous generation, which posited that cells and organisms could arise from inanimate matter. Virchow’s microscopic studies revealed cells dividing into two equal parts, which contributed to the cell theory, the other tenets of which posited that all living things are made of one cell or more, and that cells are the basic units of life. Other famous contributors to the cell theory were German physiologist Theodor Schwann and German botanist Matthias Jakob Schleiden. One of Virchow’s famous phrases was “The task of science is to stake out the limits of the knowable, and to center consciousness within them.”
As well as describing cell division, Virchow was the first to accurately identify leukemia cells in blood cancer. Despite these accomplishments, he rejected the notion that bacteria can cause disease, as well as the value of cleanliness in preventing infection. He also rejected the germ theory of Pasteur, believing that diseased tissues were caused by a malfunctioning of cells and not from an invasion of a foreign microbe.
Science writer John G. Simmons notes, “With the cellular hypothesis, Virchow expanded the research horizons of biochemistry and physiology and had great influence in the broader field of biology, where the cell doctrine eventually evolved in molecular biology, as genetics evolved and reproduction became better understood.” Today, we know that cancers result from uncontrolled cell divisions and that skin cells that heal
a wound are created from preexisting, dividing skin cells.
SEE ALSO Causes of Cancer (1761), Semmelweis’s Hand Washing (1847), Germ Theory of Disease (1862), HeLa Cells (1951), Telomerase (1984).
Artistic representation of a zygote after two cell-division steps. The zygote is the initial cell formed when a new organism is produced by the union of a sperm and an egg.
1856
Plastic • Marshall Brain
Alexander Parkes (1813–1890)
Although humans have used naturally occurring plastics such as rubber and collagen for millennia, the first manmade plastic was Parkesine, patented by Alexander Parkes in 1856. Today, the amount of plastic that surrounds us is nearly indescribable. The affordability, malleability, and durability of plastic makes it an ideal material.
One reason for the widespread use of plastic is the work of chemical engineers, who have used mass-scale processes in factories to make the production of plastic so inexpensive. Another factor is the contribution of mechanical engineers and industrial engineers who design the parts and create the molding systems to produce shaped plastic objects. Plastic is also lightweight, strong for its weight, corrosion-free, easily molded, and it comes in so many forms with many different properties. While Parkesine, made of cellulose, was often used to create synthetic ivory, modern plastics are normally made of other, higher-quality components. Polyethylene is made of long chains of carbon and hydrogen atoms, so it is essentially solidified gasoline. The length of the chains, the amount of branching, and the amount of polymerization gives polyethylene its many different properties.
Engineers and scientists have worked together to create hundreds of other types of plastics as well. Some plastics form fibers that become soft cloth or pillow stuffing. Nylon fibers, produced by Wallace Carothers at Dupont in 1935, create a strong, abrasion-resistant fabric for parachutes, backpacks, and tents. Kevlar was developed later, and is strong enough for use in bulletproof vests. Some plastics are rubbery and they become seals, gaskets, O-rings, wheels, and grips. Some plastics are clear like glass; others are completely opaque. Some are so strong that they replicate the tensile strength of steel while being flexible and light. This diversity and versatility means that engineers can use plastics to make almost anything.
SEE ALSO Roman Concrete (c. 126), Rubber (1839), Polyethylene (1933).
Plastic toy blocks of this sort are often made out of ABS (acrylonitrile butadiene styrene) plastic.
1858
Möbius Strip • Clifford A. Pickover
August Ferdinand Möbius (1790–1868)
German mathematician August Ferdinand Möbius was a shy, unsociable, absentminded professor whose most famous discovery, the Möbius strip, was made when he was almost seventy years old. To create the strip yourself, simply join the two ends of a ribbon after giving one end a 180-degree twist with respect to the other end. The result is a one-sided surface—a bug can crawl from any point on such a surface to any other point without ever crossing an edge. Try coloring a Möbius strip with a crayon. It’s impossible to color one side red and the other green because the strip has only one side.
Years after Möbius’s death, the popularity and applications of the strip grew, and it has become an integral part of mathematics, magic, science, art, engineering, literature, and music. The Möbius strip is the ubiquitous symbol for recycling where it represents the process of transforming waste materials into useful resources. Today, the Möbius strip is everywhere, from molecules and metal sculptures to postage stamps, literature, technology patents, architectural structures, and models of our entire universe.
August Möbius had simultaneously discovered his famous strip with a contemporary scholar, the German mathematician Johann Benedict Listing (1808–1882). However, Möbius seems to have taken the concept a little further than Listing, as Möbius more closely explored some of the remarkable properties of this strip.
The Möbius strip is the first one-sided surface discovered and investigated by humans. It seems far-fetched that no one had described the properties of one-sided surfaces until the mid-1800s, but history has recorded no such observations. Given that the Möbius strip is often the first and only exposure of a wide audience to the study of topology—the science of geometrical shapes and their relationships to one another—this elegant discovery deserves a place in this book.
SEE ALSO Platonic Solids (c. 350 BCE), Euclid’s Elements (c. 300 BCE), Non-Euclidean Geometry (1829), Tesseract (1888)
Multiple Möbius strips, an artwork created by Teja Kraˇsek and Cliff Pickover. The Möbius strip is the first one-sided surface discovered and investigated by humans.
1859
Darwin’s Theory of Natural Selection • Michael C. Gerald with Gloria E. Gerald
Charles Lyell (1797–1875), Thomas Malthus (1766–1834), Charles Darwin (1809–1882), Alfred Russel Wallace (1823–1913)
On the Origin of Species by Means of Natural Selection was over twenty years in its formulation and was based on a number of disparate sources and observations that Charles Darwin had the genius to integrate. While sailing on the HMS Beagle (1831–1835), he read Principles of Geology, wherein Charles Lyell proposed that the fossils embedded in rock were imprints of living beings millions of years old that no longer inhabited the earth nor resembled extant beings. In 1838, Darwin read Thomas Malthus’s An Essay on the Principle of Population, in which Malthus postulated that the rate of growth of the population was far exceeding the food supply and that, if unchecked, would have catastrophic consequences. Darwin also considered the practice of farmers who selected their best animal stock for breeding (artificial selection). The fourteen finches he found on the Galápagos Islands were similar in all respects, with the exception of the size and shape of their beaks, which were adapted to the available supply of food on their island.
Darwin was not the first to conceive of evolution, but the others lacked a coherent theory to explain its occurrence. His theory was based on natural selection. In nature, there is competition within the species for the limited resources. Those living beings that have the most favorable traits that are best adapted to their environments are most likely to survive and reproduce and pass their favorable traits on to offspring. Thus, over many generations, the species that has arisen from a common ancestor “descends with modifications.”
In the 1840s, Darwin sketched the outline of his natural selection theory in an essay. Anticipating a storm of protest to greet his anti-Creation theory, he hesitated to go public but, over the next decade, continued to gather additional evidence to bolster it. In 1858, Darwin learned that a fellow naturalist, Alfred Russel Wallace, had independently developed a theory of natural selection that was strikingly similar to his own. Darwin rapidly completed his book, Origin of Species, which appeared in 1859 and proved to be a runaway best seller and a classic in scientific literature.
SEE ALSO Agriculture (c. 10,000 BCE), Linnaean Classification of Species (1735), Artificial Selection (Selective Breeding) (1760), Darwin and the Voyages of the Beagle (1831), Fossil Record and Evolution (1836), Ecological Interactions (1859)
An 1869 photograph of Charles Darwin taken by Julia Margaret Cameron (1815–1879), who was known for her photographs of British celebrities.
1859
Ecological Interactions • Michael C. Gerald with Gloria E. Gerald
Charles Darwin (1809–1882)
Ecology examines the relations between living organisms and their environment, and it is not surprising that the relationship between or among species sharing the same ecosystem affects one another. At one end, the nature of this interaction can benefit one species at the expense of the other, to the other extreme each can benefit from the interaction. In his Origin of Species (1859), Darwin noted that the struggle for survival was greatest among members of the same species because they possess similar phenotypes and niche requirements.
WHAT’S IN A RELATIONSHIP? Predation and parasitism are situations in which only one species profits from
the interaction, while another species pays the price. Predation represents the ultimate extreme of an ecological interaction, in which one species captures and feeds on another, as an owl kills a field mouse or the carnivorous pitcher plant catches insects. In a somewhat less extreme instance—parasitism—one species (the parasite) benefits at the expense of the other (host), which derives no benefit from the interaction, as when tapeworms inhabit the intestines of a vertebrate host. Intracellular parasites, such as protozoa or bacteria, often rely upon a vector to transport the parasite to its host; the anopheles mosquito conveys the malaria-carrying protozoan parasite to its human host, for example.
In commensalism, one species receives benefit from another, which does not suffer adversely from the interplay. The remora, a tropical open-ocean-dwelling fish, lives symbiotically with sharks and eats the shark’s leftover food. The fierasfer is a small, slender fish that lives inside the cloacal cavity (the lower end of the alimentary canal) of the sea cucumber to protect itself from predators.
The most equitable of all interactions is mutualism, in which each species provides resources or services to the other resulting in mutual benefit. Lichen is a plant that results when a green alga lives symbiotically with a fungus, where the fungus gains oxygen and carbohydrate from the alga, which reciprocally obtains water, carbon dioxide, and mineral salts from the fungus.
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