The 1900s Science and Technology: Topics in the News
The 1900s Science and Technology: Topics in the NewsTHE AUTOMOBILE
THE BUILDING BLOCKS OF LIFE
ALBERT EINSTEIN'S THEORY OF RELATIVITY
Gottleib Daimler (1834–1900) and Karl Benz (1844–1929) crafted the first modern automobile in the late nineteenth century in Germany. Daimler first developed his gasoline engine to be used on a four-wheeled vehicle in 1886, and by the 1890s the two men had begun production on their motor-cars in France. However, it would be American industrialist Henry Ford (1863–1947) who truly revolutionized the auto industry. Unlike other automakers in the United States, who were designing large models for the wealthy, Ford envisioned creating practical vehicles that everyone could afford. The Quadricycle, Ford's first car, was built in 1896. A few years later,
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he founded the Ford Motor Company, and by 1904 the corporation was producing twenty-five cars each day. The most successful of Ford's early models was the Model T (nicknamed the "Tin Lizzie"), which had an engine comprised of four cylinders cast together in a single block. This innovation remains the basic design of the internal combustion engine. The Model T also featured a new transmission with three pedals, one to move forward, one to move backward, and one to brake. Thousands of Model Ts were sold in 1909, its first year of production. The car was so popular that by the end of World War I (1914–18), half the automobiles in the world were Model Ts.
Henry Ford was not the nation's sole automaker; he faced several major U.S. competitors. Ransom Eli Olds manufactured his first "Merry Oldsmobile" in 1896, while the Stanley brothers of Newton, Massachusetts, created a steam-driven car (the Stanley Steamer) in 1897. Between 1900 and 1908, 502 automobile companies were established, of which 302 failed. One of the more successful carmakers of the era was David D. Buick, whose company became the leading auto producer in 1908. That same year, Buick merged with Olds and Cadillac (two other independent companies) to form the General Motors Company. Another of America's leading auto corporations was formed in 1908, when Walter Chrysler introduced his first model.
The invention of the automobile had an immediate and dramatic impact upon the nation's lifestyle. The first major cultural shift was the rapid reduction in horse-drawn transportation. Fewer horses resulted in less manure and cleaner urban streets. Health care was improved, as physicians could make house calls to remote communities with greater ease and speed. American roads soon were filled with a variety of motor vehicles, including ambulances, postal cars, and delivery trucks, which further improved the quality of life. Throughout the decade, international interest in automobiles also increased. Technological improvements in design and mechanics stimulated worldwide consumer interest in the transportation marvel.
The history of American aviation begins in the nineteenth century with ballooning. During the Civil War, both the Union and Confederate armies used balloons for reconnaissance missions to observe enemy troop movements. Many people throughout the world believed dirigibles (gaspowered balloons) would serve as the primary means of air travel in the future. Others, however, were convinced manned flight would come about only through mechanical innovation. One of the earliest proponents of the new science of aeronautical engineering was Samuel P. Langley (1834–1906), director of the Smithsonian Institution. Langley began working with model airplanes in the 1880s. In 1896, one of his models flew three thousand feet along the Potomac River. Another aviation pioneer was French-born engineer Octave Chanute (1832–1910), who experimented with piloting gliders. Chanute had a major success in 1896, when he registered a glide of 256 feet during a test on the Indiana shore of Lake Michigan. Langley, Chanute, and many others worked tirelessly to become the first human to take flight. A national frenzy was created as journalists reported on the inventors' race to fly. In 1903, Langley built an airplane called the Aerodrome, which had a five-cylinder engine, but it was a failure. Only nine days after Langley's ill-fated attempts to fly, Orville and Wilbur Wright became the first humans to achieve engine-powered flight at Kitty Hawk, North Carolina. Their effort succeeded in large part because the brothers had focused on the interaction between the wing and air currents before designing their motorized glider.
In 1907, several years after the Wright brothers' historic achievement, inventor Alexander Graham Bell (1847–1922) established the Aerial Experiment Association (AEA). He was convinced that the Wrights' plane was extremely dangerous because it needed high speeds to take off and maintain flight. Bell experimented with a piloted flying kite that would travel only 15 miles per hour, but this prototype failed. Another member of the AEA, Thomas Selfridge, made history by becoming the first American
aviation casualty when he was killed in a crash while flying with Orville Wright. Despite these setbacks, aviation captured the public's imagination as a marvel of the modern age. By the conclusion of the first decade of the 1900s, the Wrights and others were manufacturing airplanes for both military and civilian use. In the 1910s, the airplane would see further innovations as production expanded during World War I.
Marconi and Tesla
The creation of radio is due in large measure to the work of two scientists: Guglielmo Marconi and Nikola Tesla (1856–1943). Tesla, a Croatian-born physicist, had immigrated to the United States in 1884 and had spent several years working on alternating current electrical systems for Thomas Edison. In 1893 he gave an influential lecture in St. Louis, Missouri, predicting wireless telegraphy based on spark transmission. Two years later another physicist, the Italian-born Marconi, was hailed as the discoverer of radiotelegraphy through his work with spark transmissions. Marconi insisted that he had invented the new technology independently, and he had been unaware of Tesla's remarks. The two inventors became embroiled in litigation over patent infringement for several years. Marconi's original patent was eventually disallowed, but his claim to being the "father of radio" remains, due to the fact he actually developed wireless telegraphy while Tesla's research was more theoretical. Still, Tesla's 1904 prediction that radio would someday "prove very efficient in enlightening the masses, particularly in still-uncivilized countries and less accessible regions, and that it will add materially to general safety, comfort, and convenience and maintenance of peaceful relations" was correct. Radio's discovery and evolution during the early 1900s paved the way for mass communication and an emerging "global village" later in the century.
The history of radio began in 1887, when German physicist Heinrich Hertz (1857–1894) produced electromagnetic waves from an oscillating circuit connected to an induction coil. Soon "Hertzian waves" were being studied in laboratories throughout the world. In 1895, Italian physicist Guglielmo Marconi (1874–1937) discovered that he was able to send Morse code
signals through the air. Marconi soon was joined in his studies by English physicist Oliver Lodge. Together they learned how to transmit waves of a definite length and created a receiver that could be tuned to waves of specific lengths. This discovery is now recognized as the first radio. On December 12, 1901, Marconi received history's first transatlantic wireless message, in Morse code, on his antenna at Cape Cod, Massachusetts.
The earliest radio instruments were unable to transmit the human voice. They were actual wireless telegraphs, in that they could receive only dots and dashes produced by electrified oscillations. The early 1900s was a decade during which several prominent scientists, including Marconi, Reginald Fessenden, and Lee De Forest, raced to be the first to successfully transmit the human voice. A true breakthrough occurred in 1906 with De Forest's invention of the triode vacuum tube, or audion, which was based on earlier works by Edison and John Fleming. De Forest found a means to gain greater clarity and strength when receiving radio signals by adding a third electrode to the two-electrode vacuum tube. Another advance in radio's evolution happened that same year, when Henry Dun-woody, an army general, discovered that carborundum crystals could detect electrical currents. Dunwoody's work set in motion the development of crystal receivers, which would be employed on thousands of homemade radio sets in later decades.
It would not be until the 1910s that modern broadcasting would begin. In 1912, entrepreneur David Sarnoff (1891–1971) received wireless distress messages from the Titanic ocean liner as the doomed ship was sinking following its collision with an iceberg. Sarnoff broadcast the messages by voice to retail stores owned by John Wanamaker, who earlier had installed a radio to lure customers. The incident captivated the public and made people aware of the great possibilities inherent in radio for disseminating news and entertainment. In 1916, Sarnoff joined forces with Marconi to manufacture a "Radio Music Box," priced at approximately seventy-five dollars each. By 1919, the Marconi Company had merged with General Electric to form the Radio Corporation of America (RCA). Sarnoff became RCA's first president. Its primary rival was Westinghouse Electric, which began operating the first commercially profitable radio broadcasting station (KDKA in Pittsburgh) in November 1920. Radio would come to dominate American culture during the 1920s.
THE BUILDING BLOCKS OF LIFE
American achievements in the field of biology during the 1900s were based on the scientific advances of the late nineteenth century. Much of the period's interest in biology centered on the study of genetics and the possibility of altering the genetic makeup of cells and organisms. German-born biologist Jacques Loeb (1859–1924) pioneered experimentation with parthenogenesis, the process of stimulating an egg to develop into an organism without being fertilized. Loeb believed life could be engineered, and he promoted the notion that life could eventually be created in a test tube. Critics labeled him "Dr. Frankenstein" for his manipulations of life and reproduction. His legacy can be found in the research of many later American scientists, such as John Watson and B. F. Skinner, who were influenced by Loeb's theories that life could be created, predicted, and controlled by scientific methods.
Another nineteenth-century pioneer in biology was Gregor Mendel, an Austrian monk whose experiments with plant hybrids in the 1850s and 1860s revealed the existence of dominant parental characteristics in subsequent generations of particular life forms. He discovered hereditary determinants, which he classified as either dominant (controlling the next generation's physical appearance) or recessive (not producing an apparent trait but still inherited by offspring). Little attention was paid to Mendel's discoveries until 1900, when three European biologists—Hugo de Vries, Karl Correns, and Erich von Tschmeak—independently rediscovered the monk's theories. In 1909, Danish biologist Wilhelm Johannsen coined the term gene to represent the primary unit of heredity. Americans also showed much interest in Mendel's work during the early 1900s, as breeders reasoned that his findings made it possible for them to predict the probable outcomes of specific breeding strategies. One area where Mendel's research proved to be an invaluable aide was in the study of the structure and functions of chromosomes. Columbia University graduate students Walter Sutton and W.A. Cannon were the first to hypothesize that the division of chromosomes might be the mechanism that explained Mendelian segregation. Their hypothesis was supported by findings reported in 1905 by scientists E. B. Wilson at Columbia and Nettie Stevens at Bryn Mawr University. Working independently, Wilson and Stevens each demonstrated that while all eggs possess a single X chromosome, each sperm may carry either an X or a Y chromosome. Consequently, cells in females contain two X chromosomes, and those of males have one X chromosome and one Y chromosome.
Vivisection involves the experimental use of living animals to observe physiological processes under laboratory conditions. Most physiology and endocrinology researchers performed the technique during the late nineteenth and early twentieth centuries. They believed studying the bodily functions of animal subjects was necessary to provide better health care for humans. The movement to limit experimental animal testing began in Europe in the 1870s. The American Antivivisection Society was founded in Philadelphia, Pennsylvania, in 1883. Protests against the cruelty to animals in the name of science roared during the first decade of the 1900s, alarming the research community. In their view, antivivisectionsectionists seemed to be threatening the unprecedented advances that medical science had made in the preceding decades. Scientists saw animal testing as vital to expanding knowledge in many areas, including the digestive, cardiovascular, and nervous systems. The antivivisection movement revealed the public's interest in medical ethics. The debate on the merits of vivisection continues into the new millennium.
Many of the decade's laboratory experiments in genetics were conducted on the common fruit fly, Drosophila melanogaster. Scientists chose to use these flies because they have a short reproductive cycle (ten days to three weeks), produce numerous offspring (one hundred to more than four hundred in each generation), and possess only a few chromosomes. One of the most prominent researchers to experiment with the flies was Thomas Hunt Morgan (1866–1945). He theorized that they might be helpful in testing Charles Darwin's ideas of natural selection. To accomplish his goal, Morgan developed a new type of experimental research called "microevolution," which combines concepts surrounding mutation and variation. The work of Morgan and others led directly to the "synthetic theory of evolution," which has dominated biological studies since the 1930s. According to this viewpoint, natural selection is seen as acting on gene pools, rather than on individuals. Thus, Darwin's theories on evolution are now understood through the lens of Mendel's work in genetics.
Sigmund Freud, an Austrian psychiatrist, had a tremendous impact on the twentieth century due to his theory on the psychology of human behavior. Freud stated that human behavior is based upon the workings of the unconscious mind. In his landmark text, On the Interpretation of Dreams (1900), Freud outlined his revolutionary theory. According to Freud, people often repress unpleasant thoughts and emotions, but these feelings are not totally eliminated. Rather, the negative thoughts reappear in the unconscious mind and are revealed to the person, in a distorted form, as dreams. Freud believed the key to understanding a person's unconscious fears and desires was through analysis of their dreams. Once a dream was analyzed, the doctor would assist the patient in reconstructing his or her past emotional life in order to understand the events or emotions that caused distress. According to Freud, many people's most commonly suppressed thoughts center on sexual matters. This belief scandalized many European physicians, who feared Freud was encouraging his patients' "perversity." For most of the early 1900s, Freud discussed his ideas with a small group of colleagues and students, as he was unwilling to face the hostility of the medical establishment.
Freud gained international fame in 1909, when he agreed to present his theories in a series of lectures at Clark University in Worchester, Massachusetts. Numerous leaders in American psychiatry, as well as other intellectuals, journeyed to New England to hear Freud speak during his only visit to the United States. In a series of five lectures, Freud offered a comprehensive explanation of his psychological system. He addressed numerous topics, including: the causes of and treatment for hysteria; the mechanism of repression; analysis of dreams and verbal mistakes (an incorrect word or image replaces a similar one, now referred to as "Freudian slips"); the sexuality of children; and the emotional demands of civilization. Freud's lectures sent an immediate shock wave through the American psychiatric and psychological communities. Some psychiatrists quickly adopted Freud's theories and strongly supported the idea of psychoanalysis. These physicians accepted Freud's notion that emotional problems are not the result of physical causes, but instead are rooted in the patient's own mind and experiences.
Much attention was given to Freud's idea that civilization's morality was at the root of many emotional disorders, since society advocated repressing sexual desires. The repression of one's sexual impulses, Freud explained, resulted in neurosis. While Freud was offering his theories, Victorian society's strict moral rules were being attacked by others as repressive, hypocritical, and unhealthy. Some progressive thinkers promoted sexual education as a result. Freud's theories not only changed the psychiatric profession, causing it to consider the role of the unconscious mind in people's behavior, but also spurred Americans to change their attitudes toward sex.
ALBERT EINSTEIN'S THEORY OF RELATIVITY
The scientist who had perhaps the most lasting intellectual impact upon the twentieth century was a Jewish German theoretical physicist named Albert Einstein (1879–1955). In 1905, Einstein devised his special theory of
relativity. Einstein's theory dealt with uniform linear motion at constant but high velocities. He determined that the speed of light remains constant in a vacuum, independent of the light source or the observer, and that mass and energy are equivalent. His ideas on special relativity are a landmark in human thought and have become foundation for modern physics.
Einstein's most famous formula, "E = mc2" (E represents energy, m is mass, and c is the speed of light) demonstrates that a small mass traveling at the speed of light is equivalent to a vast amount of energy. As a result of this equivalence, time and space are not absolute: What one person sees or measures may be different from that of another observer in a different frame of reference. Special relativity also debunks the existence of the ether, an invisible and undetectable substance that scientists had formerly believed filled the universe. In a famous paradox resulting from his theory, Einstein showed that time slows down at very high speeds. Consequently, an astronaut traveling through space for many years at speeds approaching that of light would discover upon his return to Earth that his twin would have become an elderly man while the astronaut would have hardly aged at all.
Since the 1840s, primitive photographic technology had been used to examine solar eclipses. A great advance was made when Warren de la Rue invented the photoheliograph, a photographic telescope with a fast shutter that could map the surface of the sun. On August 30, 1905, hundreds of astronomers gathered in Spain to observe a total solar eclipse. Although they did not obtain significant data, American astronomers were present in large numbers and participated fully with their international counterparts in studying the event. Many scientific historians cite the 1905 eclipse as the moment when American astronomy came of age.
Many American scientists dismissed Einstein's revolutionary ideas as abstract, unworkable, or nonsensical. In 1914, Einstein expanded his concepts to include nonlinear motion in a general theory of relativity. This introduced his famous theory of curved space-time. In 1921, Einstein was awarded the Nobel Prize in physics for his study of the photoelectric effect. Although some aspects of his theories on relativity eventually were verified by other scientists, his research remained controversial for decades.