Broadcaster guitar

The invention: The first commercially manufactured solid-body electric guitar, the Broadcaster revolutionized the guitar industry and changed the face of popular music The people behind the invention: Leo Fender (1909-1991), designer of affordable and easily massproduced solid-body electric guitars Les Paul (Lester William Polfuss, 1915- ), a legendary guitarist and designer of solid-body electric guitars Charlie Christian (1919-1942), an influential electric jazz guitarist of the 1930’s Early Electric Guitars It has been estimated that between 1931 and 1937, approximately twenty-seven hundred electric guitars and amplifiers were sold in the United States. The Electro String Instrument Company, run by Adolph Rickenbacker and his designer partners, George Beauchamp and Paul Barth, produced two of the first commercially manufactured electric guitars—the Rickenbacker A-22 and A-25—in 1931. The Rickenbacker models were what are known as “lap steel” or Hawaiian guitars. A Hawaiian guitar is played with the instrument lying flat across a guitarist’s knees. By the mid-1930’s, the Gibson company had introduced an electric Spanish guitar, the ES-150. Legendary jazz guitarist Charlie Christian made this model famous while playing for Benny Goodman’s orchestra. Christian was the first electric guitarist to be heard by a large American audience. He became an inspiration for future electric guitarists, because he proved that the electric guitar could have its own unique solo sound. Along with Christian, the other electric guitar figures who put the instrument on the musical map were blues guitarist T-Bone Walker, guitarist and inventor Les Paul, and engineer and inventor Leo Fender. Early electric guitars were really no more than acoustic guitars, with the addition of one or more pickups, which convert string vibrations to electrical signals that can be played through a speaker. Amplification of a guitar made it a more assertive musical instrument. The electrification of the guitar ultimately would make it more flexible, giving it a more prominent role in popular music. Les Paul, always a compulsive inventor, began experimenting with ways of producing an electric solid-body guitar in the late 1930’s. In 1929, at the age of thirteen, he had amplified his first acoustic guitar. Another influential inventor of the 1940’s was Paul Bigsby. He built a prototype solid-body guitar for country music star Merle Travis in 1947. It was Leo Fender who revolutionized the electric guitar industry by producing the first commercially viable solid-body electric guitar, the Broadcaster, in 1948.Leo Fender Leo Fender was born in the Anaheim, California, area in 1909. As a teenager, he began to build and repair guitars. By the 1930’s, Fender was building and renting out public address systems for group gatherings. In 1937, after short tenures of employment with the Division of Highways and the U.S. Tire Company, he opened a radio repair company in Fullerton, California. Always looking to expand and invent new and exciting electrical gadgets, Fender and Clayton Orr “Doc” Kauffman started the K & F Company in 1944. Kauffman was a musician and a former employee of the Electro String Instrument Company. The K & F Company lasted until 1946 and produced steel guitars and amplifiers. After that partnership ended, Fender founded the Fender Electric Instruments Company. With the help of George Fullerton, who joined the company in 1948, Fender developed the Fender Broadcaster. The body of the Broadcaster was made of a solid plank of ash wood. The corners of the ash body were rounded. There was a cutaway located under the joint with the solid maple neck, making it easier for the guitarist to access the higher frets. The maple neck was bolted to the body of the guitar, which was unusual, since most guitar necks prior to the Broadcaster had been glued to the body. Frets were positioned directly into designed cuts made in the maple of the neck. The guitar had two pickups. The Fender Electric Instruments Company made fewer than one thousand Broadcasters. In 1950, the name of the guitar was changed from the Broadcaster to the Telecaster, as the Gretsch company had already registered the name Broadcaster for some of its drums and banjos. Fender decided not to fight in court over use of the name. Leo Fender has been called the Henry Ford of the solid-body electric guitar, and the Telecaster became known as the Model T of the industry. The early Telecasters sold for $189.50. Besides being inexpensive, the Telecaster was a very durable instrument. Basically, the Telecaster was a continuation of the Broadcaster. Fender did not file for a patent on its unique bridge pickup until January 13, 1950, and he did not file for a patent on the Telecaster’s unique body shape until April 3, 1951. In the music industry during the late 1940’s, it was important for a company to unveil new instruments at trade shows. At this time, there was only one important trade show, sponsored by the National Association of Music Merchants. The Broadcaster was first sprung on the industry at the 1948 trade show in Chicago. The industry had seen nothing like this guitar ever before. This new guitar existed only to be amplified; it was not merely an acoustic guitar that had been converted. Impact The Telecaster, as it would be called after 1950, remained in continuous production for more years than any other guitar of its type and was one of the industry’s best sellers. From the beginning, it looked and sounded unique. The electrified acoustic guitars had a mellow woody tone, whereas the Telecaster had a clean twangy tone. This tone made it popular with country and blues guitarists. The Telecaster could also be played at higher volume than previous electric guitars. Because Leo Fender attempted something revolutionary by introducing an electric solid-body guitar, there was no guarantee that his business venture would succeed. Fender Electric Instruments Company had fifteen employees in 1947. At times, during the early years of the company, it looked as though Fender’s dreams would not come to fruition, but the company persevered and grew. Between 1948 and 1955 with an increase of employees, the company was able to produce ten thousand Broadcaster/Telecaster guitars. Fender had taken a big risk, but it paid off enormously. Between 1958 and the mid-1970’s, Fender produced more than 250,000 Telecasters. Other guitar manufacturers were placed in a position of having to catch up. Fender had succeeded in developing a process by which electric solid-body guitars could be manufactured profitably on a large scale. Early Guitar Pickups The first pickups used on a guitar can be traced back to the 1920’s and the efforts of Lloyd Loar, but there was not strong interest on the part of the American public for the guitar to be amplified. The public did not become intrigued until the 1930’s. Charlie Christian’s electric guitar performances with Benny Goodman woke up the public to the potential of this new and exciting sound. It was not until the 1950’s, though, that the electric guitar became firmly established. Leo Fender was the right man in the right place. He could not have known that his Fender guitars would help to usher in a whole new musical landscape. Since the electric guitar was the newest member of the family of guitars, it took some time for musical audiences to fully appreciate what it could do. The electric solid-body guitar has been called a dangerous, uncivilized instrument. The youth culture of the 1950’s found in this new guitar a voice for their rebellion. Fender unleashed a revolution not only in the construction of a guitar but also in the way popular music would be approached henceforth. Because of the ever-increasing demand for the Fender product, Fender Sales was established as a separate distribution company in 1953 by Don Randall. Fender Electric Instruments Company had fifteen employees in 1947, but by 1955, the company employed fifty people. By 1960, the number of employees had risen to more than one hundred. Before Leo Fender sold the company to CBS on January 4, 1965, for $13 million, the company occupied twenty-seven buildings and employed more than five hundred workers. Always interested in finding new ways of designing a more nearly perfect guitar, Leo Fender again came up with a remarkable guitar in 1954, with the Stratocaster. There was talk in the guitar industry that Fender had gone too far with the introduction of the Stratocaster, but it became a huge success because of its versatility. It was the first commercial solid-body electric guitar to have three pickups and a vibrato bar. It was also easier to play than the Telecaster because of its double cutaway, contoured body, and scooped back. The Stratocaster sold for $249.50. Since its introduction, the Stratocaster has undergone some minor changes, but Fender and his staff basically got it right the first time. The Gibson company entered the solid-body market in 1952 with the unveiling of the “Les Paul” model. After the Telecaster, the Les Paul guitar was the next significant solid-body to be introduced. Les Paul was a legendary guitarist who also had been experimenting with electric guitar designs for many years. The Gibson designers came up with a striking model that produced a thick rounded tone. Over the years, the Les Paul model has won a loyal following. The Precision Bass In 1951, Leo Fender introduced another revolutionary guitar, the Precision bass. At a cost of $195.50, the first electric bass would go on to dominate the market. The Fender company has manufactured numerous guitar models over the years, but the three that stand above all others in the field are the Telecaster, the Precision bass, and the Stratocaster. The Telecaster is considered to be more of a workhorse, whereas the Stratocaster is thought of as the thoroughbred of electric guitars. The Precision bass was in its own right a revolutionary guitar. With a styling that had been copied from the Telecaster, the Precision freed musicians from bulky oversized acoustic basses, which were prone to feedback. The name Precision had meaning. Fender’s electric bass made it possible, with its frets, for the precise playing of notes; many acoustic basses were fretless. The original Precision bass model was manufactured from 1951 to 1954. The next version lasted from 1954 until June of 1957. The Precision bass that went into production in June, 1957, with its split humbucking pickup, continued to be the standard electric bass on the market into the 1990’s. By 1964, the Fender Electric Instruments Company had grown enormously. In addition to Leo Fender, a number of crucial people worked for the organization, including George Fullerton and Don Randall. Fred Tavares joined the company’s research and development team in 1953. In May, 1954, Forrest White became Fender’s plant manager. All these individuals played vital roles in the success of Fender, but the driving force behind the scene was always Leo Fender. As Fender’s health deteriorated, Randall commenced negotiations with CBS to sell the Fender company. In January, 1965, CBS bought Fender for $13 million. Eventually, Leo Fender regained his health, and he was hired as a technical adviser by CBS/Fender. He continued in this capacity until 1970. He remained determined to create more guitar designs of note. Although he never again produced anything that could equal his previous success, he never stopped trying to attain a new perfection of guitar design. Fender died on March 21, 1991, in Fullerton, California. He had suffered for years from Parkinson’s disease, and he died of complications from the disease. He is remembered for his Broadcaster/ Telecaster, Precision bass, and Stratocaster, which revolutionized popular music. Because the Fender company was able to mass produce these and other solid-body electric guitars, new styles of music that relied on the sound made by an electric guitar exploded onto the scene. The electric guitar manufacturing business grew rapidly after Fender introduced mass production. Besides American companies, there are guitar companies that have flourished in Europe and Japan. The marriage between rock music and solid-body electric guitars was initiated by the Fender guitars. The Telecaster, Precision bass, and Stratocaster become synonymous with the explosive character of rock and roll music. The multi-billion-dollar music business can point to Fender as the pragmatic visionary who put the solid-body electric guitar into the forefront of the musical scene. His innovative guitars have been used by some of the most important guitarists of the rock era, including Jimi Hendrix, Eric Clapton, and Jeff Beck. More important, Fender guitars have remained bestsellers with the public worldwide. Amateur musicians purchased them by the thousands for their own entertainment. Owning and playing a Fender guitar, or one of the other electric guitars that followed, allowed these amateurs to feel closer to their musician idols. A large market for sheet music from popular artists also developed. In 1992, Fender was inducted into the Rock and Roll Hall of Fame. He is one of the few non-musicians ever to be inducted. The sound of an electric guitar is the sound of exuberance, and since the Broadcaster was first unveiled in 1948, that sound has grown to be pervasive and enormously profitable.

Breeder reactor

The invention: A plant that generates electricity from nuclear fission while creating new fuel. The person behind the invention: Walter Henry Zinn (1906-2000), the first director of the Argonne National Laboratory Producing Electricity with More Fuel The discovery of nuclear fission involved both the discovery that the nucleus of a uranium atom would split into two lighter elements when struck by a neutron and the observation that additional neutrons, along with a significant amount of energy, were released at the same time. These neutrons might strike other atoms and cause them to fission (split) also. That, in turn, would release more energy and more neutrons, triggering a chain reaction as the process continued to repeat itself, yielding a continuing supply of heat. Besides the possibility that an explosive weapon could be constructed, early speculation about nuclear fission included its use in the generation of electricity. The occurrence of World War II (1939- 1945) meant that the explosive weapon would be developed first. Both the weapons technology and the basic physics for the electrical reactor had their beginnings in Chicago with the world’s first nuclear chain reaction. The first self-sustaining nuclear chain reaction occurred in a laboratory at the University of Chicago on December 2, 1942. It also became apparent at that time that there was more than one way to build a bomb. At this point, two paths were taken: One was to build an atomic bomb with enough fissionable uranium in it to explode when detonated, and another was to generate fissionable plutonium and build a bomb. Energy was released in both methods, but the second method also produced another fissionable substance. The observation that plutonium and energy could be produced together meant that it would be possible to design electric power systems that would produce fissionable plutonium in quantities as large as, or larger than, the amount of fissionable material consumed. This is the breeder concept, the idea that while using up fissionable uranium 235, another fissionable element can be made. The full development of this concept for electric power was delayed until the end of WorldWar II. Electricity from Atomic Energy On August 1, 1946, the Atomic Energy Commission (AEC) was established to control the development and explore the peaceful uses of nuclear energy. The Argonne National Laboratory was assigned the major responsibilities for pioneering breeder reactor technologies.Walter Henry Zinn was the laboratory’s first director. He led a team that planned a modest facility (Experimental Breeder Reactor I, or EBR-I) for testing the validity of the breeding principle. Planning for this had begun in late 1944 and grew as a natural extension of the physics that developed the plutonium atomic bomb. The conceptual design details for a breeder-electric reactor were reasonably complete by late 1945. On March 1, 1949, the AEC announced the selection of a site in Idaho for the National Reactor Station (later to be named the Idaho National Engineering Laboratory, or INEL). Construction at the INEL site in Arco, Idaho, began in October, 1949. Critical mass was reached in August, 1951. (“Critical mass” is the amount and concentration of fissionable material required to produce a self-sustaining chain reaction.) The system was brought to full operating power, 1.1 megawatts of thermal power, on December 19, 1951. The next day, December 20, at 11:00 a.m., steam was directed to a turbine generator. At 1:23 p.m., the generator was connected to the electrical grid at the site, and “electricity flowed from atomic energy,” in the words of Zinn’s console log of that day. Approximately 200 kilowatts of electric power were generated most of the time that the reactor was run. This was enough to satisfy the needs of the EBR-I facilities. The reactor was shut down in 1964 after five years of use primarily as a test facility. It had also produced the first pure plutonium. With the first fuel loading, a conversion ratio of 1.01 was achieved, meaning that more new fuel was generated than was consumed by about 1 percent. When later fuel loadings were made with plutonium, the conversion ratios were more favorable, reaching as high as 1.27. EBR-I was the first reactor to generate its own fuel and the first power reactor to use plutonium for fuel. The use of EBR-I also included pioneering work on fuel recovery and reprocessing. During its five-year lifetime, EBR-I operated with four different fuel loadings, each designed to establish specific benchmarks of breeder technology. This reactor was seen as the first in a series of increasingly large reactors in a program designed to develop breeder technology. The reactor was replaced by EBR-II, which had been proposed in 1953 and was constructed from 1955 to 1964. EBR-II was capable of producing 20 megawatts of electrical power. It was approximately fifty times more powerful than EBR-I but still small compared to light-water commercial reactors of 600 to 1,100 megawatts in use toward the end of the twentieth century. Consequences The potential for peaceful uses of nuclear fission were dramatized with the start-up of EBR-I in 1951: It was the first in the world to produce electricity, while also being the pioneer in a breeder reactor program. The breeder program was not the only reactor program being developed, however, and it eventually gave way to the light-water reactor design for use in the United States. Still, if energy resources fall into short supply, it is likely that the technologies first developed with EBR-I will find new importance. In France and Japan, commercial reactors make use of breeder reactor technology; these reactors require extensive fuel reprocessing. Following the completion of tests with plutonium loading in 1964, EBR-I was shut down and placed in standby status. In 1966, it was declared a national historical landmark under the stewardship of the U.S. Department of the Interior. The facility was opened to the public in June, 1975.

Blood transfusion

The invention: A technique that greatly enhanced surgery patients’ chances of survival by replenishing the blood they lose in surgery with a fresh supply. The people behind the invention: Charles Drew (1904-1950), American pioneer in blood transfusion techniques George Washington Crile (1864-1943), an American surgeon, author, and brigadier general in the U.S. Army Medical Officers’ Reserve Corps Alexis Carrel (1873-1944), a French surgeon Samuel Jason Mixter (1855-1923), an American surgeon Nourishing Blood Transfusions It is impossible to say when and where the idea of blood transfusion first originated, although descriptions of this procedure are found in ancient Egyptian and Greek writings. The earliest documented case of a blood transfusion is that of Pope Innocent VII. In April, 1492, the pope, who was gravely ill, was transfused with the blood of three young boys. As a result, all three boys died without bringing any relief to the pope. In the centuries that followed, there were occasional descriptions of blood transfusions, but it was not until the middle of the seventeenth century that the technique gained popularity following the English physician and anatomistWilliam Harvey’s discovery of the circulation of the blood in 1628. In the medical thought of those times, blood transfusion was considered to have a nourishing effect on the recipient. In many of those experiments, the human recipient received animal blood, usually from a lamb or a calf. Blood transfusion was tried as a cure for many different diseases, mainly those that caused hemorrhages, as well as for other medical problems and even for marital problems. Blood transfusions were a dangerous procedure, causing many deaths of both donor and recipient as a result of excessive blood loss, infection, passage of blood clots into the circulatory systems of the recipients, passage of air into the blood vessels (air embolism), and transfusion reaction as a result of incompatible blood types. In the mid-nineteenth century, blood transfusions from animals to humans stopped after it was discovered that the serum of one species agglutinates and dissolves the blood cells of other species. A sharp drop in the use of blood transfusion came with the introduction of physiologic salt solution in 1875. Infusion of salt solution was simple and was safer than blood transfusion.Direct-Connection Blood Transfusions In 1898, when GeorgeWashington Crile began his work on blood transfusions, the major obstacle he faced was solving the problem of blood clotting during transfusions. He realized that salt solutions were not helpful in severe cases of blood loss, when there is a need to restore the patient to consciousness, steady the heart action, and raise the blood pressure. At that time, he was experimenting with indirect blood transfusions by drawing the blood of the donor into a vessel, then transferring it into the recipient’s vein by tube, funnel, and cannula, the same technique used in the infusion of saline solution. The solution to the problem of blood clotting came in 1902 when Alexis Carrel developed the technique of surgically joining blood vessels without exposing the blood to air or germs, either of which can lead to clotting. Crile learned this technique from Carrel and used it to join the peripheral artery in the donor to a peripheral vein of the recipient. Since the transfused blood remained sealed in the inner lining of the vessels, blood clotting did not occur. The first human blood transfusion of this type was performed by Crile in December, 1905. The patient, a thirty-five-year-old woman, was transfused by her husband but died a few hours after the procedure. The second, but first successful, transfusion was performed on August 8, 1906. The patient, a twenty-three-year-old male, suffered from severe hemorrhaging following surgery to remove kidney stones. After all attempts to stop the bleeding were exhausted with no results, and the patient was dangerously weak, transfusion was considered as a last resort. One of the patient’s brothers was the dofew days later, another transfusion was done. This time, too, he showed remarkable improvement, which continued until his complete recovery. For his first transfusions, Crile used the Carrel suture method, which required using very fine needles and thread. It was a very delicate and time-consuming procedure. At the suggestion of Samuel Jason Mixter, Crile developed a new method using a short tubal device with an attached handle to connect the blood vessels. By this method, 3 or 4 centimeters of the vessels to be connected were surgically exposed, clamped, and cut, just as under the previous method. Yet, instead of suturing of the blood vessels, the recipient’s vein was passed through the tube and then cuffed back over the tube and tied to it. Then the donor’s artery was slipped over the cuff. The clamps were opened, and blood was allowed to flow from the donor to the recipient. In order to accommodate different-sized blood vessels, tubes of four different sizes were made, ranging in diameter from 1.5 to 3 millimeters.Impact, Crile’s method was the preferred method of blood transfusion for a number of years. Following the publication of his book on transfusion, a number of modifications to the original method were published in medical journals. In 1913, Edward Lindeman developed a method of transfusing blood simply by inserting a needle through the patient’s skin and into a surface vein, making it for the first time a nonsurgical method. This method allowed one to measure the exact quantity of blood transfused. It also allowed the donor to serve in multiple transfusions. This development opened the field of transfusions to all physicians. Lindeman’s needle and syringe method also eliminated another major drawback of direct blood transfusion: the need to have both donor and recipient right next to each other.

Birth control pill

The invention: An orally administered drug that inhibits ovulation in women, thereby greatly reducing the chance of pregnancy. The people behind the invention: Gregory Pincus (1903-1967), an American biologist Min-Chueh Chang (1908-1991), a Chinese-born reproductive biologist John Rock (1890-1984), an American gynecologist Celso-Ramon Garcia (1921- ), a physician Edris Rice-Wray (1904- ), a physician Katherine Dexter McCormick (1875-1967), an American millionaire Margaret Sanger (1879-1966), an American activist An Ardent Crusader Margaret Sanger was an ardent crusader for birth control and family planning. Having decided that a foolproof contraceptive was necessary, Sanger met with her friend, the wealthy socialite Katherine Dexter McCormick. A1904 graduate in biology from the Massachusetts Institute of Technology, McCormick had the knowledge and the vision to invest in biological research. Sanger arranged a meeting between McCormick and Gregory Pincus, head of the Worcester Institutes of Experimental Biology. After listening to Sanger’s pleas for an effective contraceptive and McCormick’s offer of financial backing, Pincus agreed to focus his energies on finding a pill that would prevent pregnancy. Pincus organized a team to conduct research on both laboratory animals and humans. The laboratory studies were conducted under the direction of Min-Chueh Chang, a Chinese-born scientist who had been studying sperm biology, artificial insemination, and in vitro fertilization. The goal of his research was to see whether pregnancy might be prevented by manipulation of the hormones usually found in a woman.It was already known that there was one time when a woman could not become pregnant—when she was already pregnant. In 1921, Ludwig Haberlandt, an Austrian physiologist, had transplanted the ovaries from a pregnant rabbit into a nonpregnant one. The latter failed to produce ripe eggs, showing that some substance from the ovaries of a pregnant female prevents ovulation. This substance was later identified as the hormone progesterone by George W. Corner, Jr., and Willard M. Allen in 1928. If progesterone could inhibit ovulation during pregnancy, maybe progesterone treatment could prevent ovulation in nonpregnant females as well. In 1937, this was shown to be the case by scientists from the University of Pennsylvania, who prevented ovulation in rabbits with injections of progesterone. It was not until 1951, however, when Carl Djerassi and other chemists devised inexpensive ways of producing progesterone in the laboratory, that serious consideration was given to the medical use of progesterone. The synthetic version of progesterone was called “progestin.” Testing the Pill In the laboratory, Chang tried more than two hundred different progesterone and progestin compounds, searching for one that would inhibit ovulation in rabbits and rats. Finally, two compounds were chosen: progestins derived from the root of a wild Mexican yam. Pincus arranged for clinical tests to be carried out by Celso- Ramon Garcia, a physician, and John Rock, a gynecologist. Rock had already been conducting experiments with progesterone as a treatment for infertility. The treatment was effective in some women but required that large doses of expensive progesterone be injected daily. Rock was hopeful that the synthetic progestin that Chang had found effective in animals would be helpful in infertile women as well. With Garcia and Pincus, Rock treated another group of fifty infertile women with the synthetic progestin. After treatment ended, seven of these previously infertile women became pregnant within half a year. Garcia, Pincus, and Rock also took several physiological measurements of the women while they were taking the progestin and were able to conclude that ovulation did not occur while the women were taking the progestin pill.Having shown that the hormone could effectively prevent ovulation in both animals and humans, the investigators turned their attention back to birth control. They were faced with several problems: whether side effects might occur in women using progestins for a long time, and whether women would remember to take the pill day after day, for months or even years. To solve these problems, the birth control pill was tested on a large scale. Because of legal problems in the United States, Pincus decided to conduct the test in Puerto Rico. The test started in April of 1956. Edris Rice-Wray, a physician, was responsible for the day-to-day management of the project. As director of the Puerto Rico Family Planning Association, she had seen firsthand the need for a cheap, reliable contraceptive. The women she recruited for the study were married women from a low-income population living in a housing development in Río Piedras, a suburb of San Juan. Word spread quickly, and soon women were volunteering to take the pill that would prevent pregnancy. In the first study, 221 women took a pill containing 10 milligrams of progestin and 0.15 milligrams of estrogen. (The estrogen was added to help control breakthrough bleeding.) Results of the test were reported in 1957. Overall, the pill proved highly effective in preventing conception. None of the women who took the pill according to directions became pregnant, and most women who wanted to get pregnant after stopping the pill had no difficulty. Nevertheless, 17 percent of the women had some unpleasant reactions, such as nausea or dizziness. The scientists believed that these mild side effects, as well as one death from congestive heart failure, were unrelated to the use of the pill. Even before the final results were announced, additional field tests were begun. In 1960, the U.S. Food and Drug Administration (FDA) approved the use of the pill developed by Pincus and his collaborators as an oral contraceptive.Consequences Within two years of approval by the FDA, more than a million women in the United States were using the birth control pill. New contraceptives were developed in the 1960’s and 1970’s, but the birth control pill remains the most widely used method of preventing pregnancy. More than 60 million women use the pill worldwide. The greatest impact of the pill has been in the social and political world. Before Sanger began the push for the pill, birth control was regarded often as socially immoral and often illegal as well. Women in those post-World War II years were expected to have a lifelong career as a mother to their many children. With the advent of the pill, a radical change occurred in society’s attitude toward women’s work.Women had increased freedom to work and enter careers previously closed to them because of fears that they might get pregnant. Women could control more precisely when they would get pregnant and how many children they would have. The women’s movement of the 1960’s—with its change to more liberal social and sexual values—gained much of its strength from the success of the birth control pill.

BINAC computer

The invention: The world’s first electronic general-purpose digital computer. The people behind the invention: John Presper Eckert (1919-1995), an American electrical engineer John W. Mauchly (1907-1980), an American physicist John von Neumann (1903-1957), a Hungarian American mathematician Alan Mathison Turing (1912-1954), an English mathematician Computer Evolution In the 1820’s, there was a need for error-free mathematical and astronomical tables for use in navigation, unreliable versions of which were being produced by human “computers.” The problem moved English mathematician and inventor Charles Babbage to design and partially construct some of the earliest prototypes of modern computers, with substantial but inadequate funding from the British government. In the 1880’s, the search by the U.S. Bureau of the Census for a more efficient method of compiling the 1890 census led American inventor Herman Hollerith to devise a punched-card calculator, a machine that reduced by several years the time required to process the data. The emergence of modern electronic computers began during World War II (1939-1945), when there was an urgent need in the American military for reliable and quickly produced mathematical tables that could be used to aim various types of artillery. The calculation of very complex tables had progressed somewhat since Babbage’s day, and the human computers were being assisted by mechanical calculators. Still, the growing demand for increased accuracy and efficiency was pushing the limits of these machines. Finally, in 1946, following three years of intense work at the University of Pennsylvania’s Moore School of Engineering, John Presper Eckert and John W. Mauchly presented their solution to the problems in the form of the Electronic Numerical Integrator and Calculator (ENIAC) the world’s first electronic general-purpose digital computer. The ENIAC, built under a contract with the Army’s Ballistic Research Laboratory, became a great success for Eckert and Mauchly, but even before it was completed, they were setting their sights on loftier targets. The primary drawback of the ENIAC was the great difficulty involved in programming it. Whenever the operators needed to instruct the machine to shift from one type of calculation to another, they had to reset a vast array of dials and switches, unplug and replug numerous cables, and make various other adjustments to the multiple pieces of hardware involved. Such a mode of operation was deemed acceptable for the ENIAC because, in computing firing tables, it would need reprogramming only occasionally. Yet if instructions could be stored in a machine’s memory, along with the data, such a machine would be able to handle a wide range of calculations with ease and efficiency. The Turing Concept The idea of a stored-program computer had first appeared in a paper published by English mathematician Alan Mathison Turing in 1937. In this paper, Turing described a hypothetical machine of quite simple design that could be used to solve a wide range of logical and mathematical problems. One significant aspect of this imaginary Turing machine was that the tape that would run through it would contain both information to be processed and instructions on how to process it. The tape would thus be a type of memory device, storing both the data and the program as sets of symbols that the machine could “read” and understand. Turing never attempted to construct this machine, and it was not until 1946 that he developed a design for an electronic stored-program computer, a prototype of which was built in 1950. In the meantime, John von Neumann, a Hungarian American mathematician acquainted with Turing’s ideas, joined Eckert and Mauchly in 1944 and contributed to the design of ENIAC’s successor, the Electronic Discrete Variable Automatic Computer (EDVAC), another project financed by the Army. The EDVAC was the first computer designed to incorporate the concept of the stored program.In March of 1946, Eckert and Mauchly, frustrated by a controversy over patent rights for the ENIAC, resigned from the Moore School. Several months later, they formed the Philadelphiabased Electronic Control Company on the strength of a contract from the National Bureau of Standards and the Census Bureau to build a much grander computer, the Universal Automatic Computer (UNIVAC). They thus abandoned the EDVAC project, which was finally completed by the Moore School in 1952, but they incorporated the main features of the EDVAC into the design of the UNIVAC. Building the UNIVAC, however, proved to be much more involved and expensive than anticipated, and the funds provided by the original contract were inadequate. Eckert and Mauchly, therefore, took on several other smaller projects in an effort to raise funds. On October 9, 1947, they signed a contract with the Northrop Corporation of Hawthorne, California, to produce a relatively small computer to be used in the guidance system of a top-secret missile called the Snark, which Northrop was building for the Air Force. This computer, the Binary Automatic Computer (BINAC), turned out to be Eckert and Mauchly’s first commercial sale and the first stored-program computer completed in the United States. The BINAC was designed to be at least a preliminary version of a compact, airborne computer. It had two main processing units. These contained a total of fourteen hundred vacuum tubes, a drastic reduction from the eighteen thousand used in the ENIAC. There were also two memory units, as well as two power supplies, an input converter unit, and an input console, which used either a typewriter keyboard or an encoded magnetic tape (the first time such tape was used for computer input). Because of its dual processing, memory, and power units, the BINAC was actually two computers, each of which would continually check its results against those of the other in an effort to identify errors. The BINAC became operational in August, 1949. Public demonstrations of the computer were held in Philadelphia from August 18 through August 20.Impact The design embodied in the BINAC is the real source of its significance. It demonstrated successfully the benefits of the dual processor design for minimizing errors, a feature adopted in many subsequent computers. It showed the suitability of magnetic tape as an input-output medium. Its most important new feature was its ability to store programs in its relatively spacious memory, the principle that Eckert, Mauchly, and von Neumann had originally designed into the EDVAC. In this respect, the BINAC was a direct descendant of the EDVAC. In addition, the stored-program principle gave electronic computers new powers, quickness, and automatic control that, as they have continued to grow, have contributed immensely to the aura of intelligence often associated with their operation. The BINAC successfully demonstrated some of these impressive new powers in August of 1949 to eager observers from a number of major American corporations. It helped to convince many influential leaders of the commercial segment of society of the promise of electronic computers. In doing so, the BINAC helped to ensure the further evolution of computers. See also Apple II computer; BINAC computer; Colossus computer; ENIAC computer; IBM Model 1401 computer; Personal computer; Supercomputer; UNIVAC computer.

Bathysphere

The invention: The first successful chamber for manned deep-sea diving missions. The people behind the invention: William Beebe (1877-1962), an American naturalist and curator of ornithology Otis Barton (1899- ), an American engineer John Tee-Van (1897-1967), an American general associate with the New York Zoological Society Gloria Hollister Anable (1903?-1988), an American research associate with the New York Zoological Society Inner Space Until the 1930’s, the vast depths of the oceans had remained largely unexplored, although people did know something of the ocean’s depths. Soundings and nettings of the ocean bottom had been made many times by a number of expeditions since the 1870’s. Diving helmets had allowed humans to descend more than 91 meters below the surface, and the submarine allowed them to reach a depth of nearly 120 meters. There was no firsthand knowledge, however, of what it was like in the deepest reaches of the ocean: inner space. The person who gave the world the first account of life at great depths wasWilliam Beebe. When he announced in 1926 that he was attempting to build a craft to explore the ocean, he was already a well-known naturalist. Although his only degrees had been honorary doctorates, he was graduated as a special student in the Department of Zoology of Columbia University in 1898. He began his lifelong association with the New York Zoological Society in 1899. It was during a trip to the Galápagos Islands off the west coast of South America that Beebe turned his attention to oceanography. He became the first scientist to use a diving helmet in fieldwork, swimming in the shallow waters. He continued this shallow-water work at the new station he established in 1928, with the permission of English authorities, on the tiny island of Nonesuch in the Bermudas. Beebe realized, however, that he had reached the limits of the current technology and that to study the animal life of the ocean depths would require a new approach. A New Approach While he was considering various cylindrical designs for a new deep-sea exploratory craft, Beebe was introduced to Otis Barton. Barton, a young New Englander who had been trained as an engineer at Harvard University, had turned to the problems of ocean diving while doing postgraduate work at Columbia University. In December, 1928, Barton brought his blueprints to Beebe. Beebe immediately saw that Barton’s design was what he was looking for, and the two went ahead with the construction of Barton’s craft. The “bathysphere,” as Beebe named the device, weighed 2,268 kilograms and had a diameter of 1.45 meters and steel walls 3.8 centimeters thick. The door, weighing 180 kilograms, would be fastened over a manhole with ten bolts. Four windows, made of fused quartz, were ordered from the General Electric Company at a cost of $500 each. A 250-watt water spotlight lent by the Westinghouse Company provided the exterior illumination, and a telephone lent by the Bell Telephone Laboratory provided a means of communicating with the surface. The breathing apparatus consisted of two oxygen tanks that allowed 2 liters of oxygen per minute to escape into the sphere. During the dive, the carbon dioxide and moisture were removed, respectively, by trays containing soda lime and calcium chloride. A winch would lower the bathysphere on a steel cable. In early July, 1930, after several test dives, the first manned dive commenced. Beebe and Barton descended to a depth of 244 meters. A short circuit in one of the switches showered them with sparks momentarily, but the descent was largely a success. Beebe and Barton had descended farther than any human. Two more days of diving yielded a final dive record of 435 meters below sea level. Beebe and the other members of his staff (ichthyologist John Tee-Van and zoologist Gloria Hollister Anable) saw many species of fish and other marine life that previously had been seen only after being caught in nets. These first dives proved that an undersea exploratory craft had potential value, at least for deep water. After 1932, the bathysphere went on display at the Century of Progress Exhibition in Chicago. In late 1933, the National Geographic Society offered to sponsor another series of dives. Although a new record was not a stipulation, Beebe was determined to supply one. The bathysphere was completely refitted before the new dives. An unmanned test dive to 920 meters was made on August 7, 1934, once again off Nonesuch Island. Minor adjustments were made, and on the morning of August 11, the first dive commenced, attaining a depth of 765 meters and recording a number of new scientific observations. Several days later, on August 15, the weather was again right for the dive. This dive also paid rich dividends in the number of species of deep-sea life observed. Finally, with only a few turns of cable left on the winch spool, the bathysphere reached a record depth of 923 meters— almost a kilometer below the ocean’s surface.Impact Barton continued to work on the bathysphere design for some years. It was not until 1948, however, that his new design, the benthoscope, was finally constructed. It was similar in basic design to the bathysphere, though the walls were increased to withstand greater pressures. Other improvements were made, but the essential strengths and weaknesses remained. On August 16, 1949, Barton, diving alone, broke the record he and Beebe had set earlier, reaching a depth of 1,372 meters off the coast of Southern California. The bathysphere effectively marked the end of the tethered exploration of the deep, but it pointed the way to other possibilities. The first advance in this area came in 1943, when undersea explorer Jacques-Yves Cousteau and engineer Émile Gagnan developed the Aqualung underwater breathing apparatus, which made possible unfettered and largely unencumbered exploration down to about 60 meters. This was by no means deep diving, but it was clearly a step along the lines that Beebe had envisioned for underwater research. A further step came in the development of the bathyscaphe by 102 / Bathysphere Auguste Piccard, the renowned Swiss physicist, who, in the 1930’s, had conquered the stratosphere in high-altitude balloons. The bathyscaphe was a balloon that operated in reverse. Aspherical steel passenger cabin was attached beneath a large float filled with gasoline for buoyancy. Several tons of iron pellets held by electromagnets acted as ballast. The bathyscaphe would sink slowly to the bottom of the ocean, and when its passengers wished to return, the ballast would be dumped. The craft would then slowly rise to the surface. On September 30, 1953, Piccard touched bottom off the coast of Italy, some 3,000 meters below sea level.

Bathyscaphe

The invention: A submersible vessel capable of exploring the deepest trenches of the world’s oceans. The people behind the invention: William Beebe (1877-1962), an American biologist and explorer Auguste Piccard (1884-1962), a Swiss-born Belgian physicist Jacques Piccard (1922- ), a Swiss ocean engineer Early Exploration of the Deep Sea The first human penetration of the deep ocean was made byWilliam Beebe in 1934, when he descended 923 meters into the Atlantic Ocean near Bermuda. His diving chamber was a 1.5-meter steel ball that he named Bathysphere, from the Greek word bathys (deep) and the word sphere, for its shape. He found that a sphere resists pressure in all directions equally and is not easily crushed if it is constructed of thick steel. The bathysphere weighed 2.5 metric tons. It had no buoyancy and was lowered from a surface ship on a single 2.2-centimeter cable; a broken cable would have meant certain death for the bathysphere’s passengers. Numerous deep dives by Beebe and his engineer colleague, Otis Barton, were the first uses of submersibles for science. Through two small viewing ports, they were able to observe and photograph many deep-sea creatures in their natural habitats for the first time. They also made valuable observations on the behavior of light as the submersible descended, noting that the green surface water became pale blue at 100 meters, dark blue at 200 meters, and nearly black at 300 meters. A technique called “contour diving” was particularly dangerous. In this practice, the bathysphere was slowly towed close to the seafloor. On one such dive, the bathysphere narrowly missed crashing into a coral crag, but the explorers learned a great deal about the submarine geology of Bermuda and the biology of a coral-reef community. Beebe wrote several popular and scientific books about his adventures that did much to arouse interest in the ocean. Testing the Bathyscaphe The next important phase in the exploration of the deep ocean was led by the Swiss physicist Auguste Piccard. In 1948, he launched a new type of deep-sea research craft that did not require a cable and that could return to the surface by means of its own buoyancy. He called the craft a bathyscaphe, which is Greek for “deep boat.” Piccard began work on the bathyscaphe in 1937, supported by a grant from the Belgian National Scientific Research Fund. The German occupation of Belgium early in World War II cut the project short, but Piccard continued his work after the war. The finished bathyscaphe was named FNRS 2, for the initials of the Belgian fund that had sponsored the project. The vessel was ready for testing in the fall of 1948. The first bathyscaphe, as well as later versions, consisted of two basic components: first, a heavy steel cabin to accommodate observers, which looked somewhat like an enlarged version of Beebe’s bathysphere; and second, a light container called a float, filled with gasoline, that provided lifting power because it was lighter than water. Enough iron shot was stored in silos to cause the vessel to descend. When this ballast was released, the gasoline in the float gave the bathyscaphe sufficient buoyancy to return to the surface. Piccard’s bathyscaphe had a number of ingenious devices. Jacques- Yves Cousteau, inventor of the Aqualung six years earlier, contributed a mechanical claw that was used to take samples of rocks, sediment, and bottom creatures. A seven-barreled harpoon gun, operated by water pressure, was attached to the sphere to capture specimens of giant squids or other large marine animals for study. The harpoons had electrical-shock heads to stun the “sea monsters,” and if that did not work, the harpoon could give a lethal injection of strychnine poison. Inside the sphere were various instruments for measuring the deep-sea environment, including a Geiger counter for monitoring cosmic rays. The air-purification system could support two people for up to twenty-four hours. The bathyscaphe had a radar mast to broadcast its location as soon as it surfaced. This was essential because there was no way for the crew to open the sphere from the inside.The FNRS 2 was first tested off the Cape Verde Islands with the assistance of the French navy. Although Piccard descended to only 25 meters, the dive demonstrated the potential of the bathyscaphe. On the second dive, the vessel was severely damaged by waves, and further tests were suspended. Aredesigned and rebuilt bathyscaphe, renamed FNRS 3 and operated by the French navy, descended to a depth of 4,049 meters off Dakar, Senegal, on the west coast of Africa in early 1954. In August, 1953, Auguste Piccard, with his son Jacques, launched a greatly improved bathyscaphe, the Trieste, which they named for the Italian city in which it was built. In September of the same year, the Trieste successfully dived to 3,150 meters in the Mediterranean Sea. The Piccards glimpsed, for the first time, animals living on the seafloor at that depth. In 1958, the U.S. Navy purchased the Trieste and transported it to California, where it was equipped with a new cabin designed to enable the vessel to reach the seabed of the great oceanic trenches. Several successful descents were made in the Pacific by Jacques Piccard, and on January 23, 1960, Piccard, accompanied by Lieutenant DonaldWalsh of the U.S. Navy, dived a record 10,916 meters to the bottom of the Mariana Trench near the island of Guam. Impact The oceans have always raised formidable barriers to humanity’s curiosity and understanding. In 1960, two events demonstrated the ability of humans to travel underwater for prolonged periods and to observe the extreme depths of the ocean. The nuclear submarine Triton circumnavigated the world while submerged, and Jacques Piccard and Lieutenant Donald Walsh descended nearly 11 kilometers to the bottom of the ocean’s greatest depression aboard the Trieste. After sinking for four hours and forty-eight minutes, the Trieste landed in the Challenger Deep of the Mariana Trench, the deepest known spot on the ocean floor. The explorers remained on the bottom for only twenty minutes, but they answered one of the biggest questions about the sea: Can animals live in the immense cold and pressure of the deep trenches? Observations of red shrimp and flatfishes proved that the answer was yes. The Trieste played another important role in undersea exploration when, in 1963, it located and photographed the wreckage of the nuclear submarine Thresher. The Thresher had mysteriously disappeared on a test dive off the New England coast, and the Navy had been unable to find a trace of the lost submarine using surface vessels equipped with sonar and remote-control cameras on cables. Only the Trieste could actually search the bottom. On its third dive, the bathyscaphe found a piece of the wreckage, and it eventually photographed a 3,000-meter trail of debris that led to Thresher‘s hull, at a depth of 2.5 kilometers.These exploits showed clearly that scientific submersibles could be used anywhere in the ocean. Piccard’s work thus opened the last geographic frontier on Earth.

BASIC programming language

The invention: An interactive computer system and simple programming language that made it easier for nontechnical people to use computers. The people behind the invention: John G. Kemeny (1926-1992), the chairman of Dartmouth’s mathematics department Thomas E. Kurtz (1928- ), the director of the Kiewit Computation Center at Dartmouth Bill Gates (1955- ), a cofounder and later chairman of the board and chief operating officer of the Microsoft Corporation The Evolution of Programming The first digital computers were developed duringWorldWar II (1939-1945) to speed the complex calculations required for ballistics, cryptography, and other military applications. Computer technology developed rapidly, and the 1950’s and 1960’s saw computer systems installed throughout the world. These systems were very large and expensive, requiring many highly trained people for their operation. The calculations performed by the first computers were determined solely by their electrical circuits. In the 1940’s, The American mathematician John von Neumann and others pioneered the idea of computers storing their instructions in a program, so that changes in calculations could be made without rewiring their circuits. The programs were written in machine language, long lists of zeros and ones corresponding to on and off conditions of circuits. During the 1950’s, “assemblers” were introduced that used short names for common sequences of instructions and were, in turn, transformed into the zeros and ones intelligible to the computer. The late 1950’s saw the introduction of high-level languages, notably Formula Translation (FORTRAN), CommonBusinessOriented Language (COBOL), and Algorithmic Language (ALGOL), which used English words to communicate instructions to the computer. Unfortunately, these high-level languages were complicated; they required some knowledge of the computer equipment and were designed to be used by scientists, engineers, and other technical experts. Developing BASIC John G. Kemeny was chairman of the department of mathematics at Dartmouth College in Hanover, New Hampshire. In 1962, Thomas E. Kurtz, Dartmouth’s computing director, approached Kemeny with the idea of implementing a computer system at Dartmouth College. Both men were dedicated to the idea that liberal arts students should be able to make use of computers. Although the English commands of FORTRAN and ALGOL were a tremendous improvement over the cryptic instructions of assembly language, they were both too complicated for beginners. Kemeny convinced Kurtz that they needed a completely new language, simple enough for beginners to learn quickly, yet flexible enough for many different kinds of applications. The language they developed was known as the “Beginner’s Allpurpose Symbolic Instruction Code,” or BASIC. The original language consisted of fourteen different statements. Each line of a BASIC program was preceded by a number. Line numbers were referenced by control flow statements, such as, “IF X = 9 THEN GOTO 200.” Line numbers were also used as an editing reference. If line 30 of a program contained an error, the programmer could make the necessary correction merely by retyping line 30. Programming in BASIC was first taught at Dartmouth in the fall of 1964. Students were ready to begin writing programs after two hours of classroom lectures. By June of 1968, more than 80 percent of the undergraduates at Dartmouth could write a BASIC program. Most of them were not science majors and used their programs in conjunction with other nontechnical courses. Kemeny and Kurtz, and later others under their supervision, wrote more powerful versions of BASIC that included support for graphics on video terminals and structured programming. The creators of BASIC, however, always tried to maintain their original design goal of keeping BASIC simple enough for beginners. Consequences Kemeny and Kurtz encouraged the widespread adoption of BASIC by allowing other institutions to use their computer system and by placing BASIC in the public domain. Over time, they shaped BASIC into a powerful language with numerous features added in response to the needs of its users. What Kemeny and Kurtz had not foreseen was the advent of the microprocessor chip in the early 1970’s, which revolutionized computer technology. By 1975, microcomputer kits were being sold to hobbyists for well under a thousand dollars. The earliest of these was the Altair. That same year, prelaw studentWilliam H. Gates (1955- ) was persuaded by a friend, Paul Allen, to drop out of Harvard University and help create a version of BASIC that would run on the Altair. Gates and Allen formed a company, Microsoft Corporation, to sell their BASIC interpreter, which was designed to fit into the tiny memory of the Altair. It was about as simple as the original Dartmouth BASIC but had to depend heavily on the computer hardware. Most computers purchased for home use still include a version of Microsoft Corporation’s BASIC. See also BINAC computer; COBOL computer language; FORTRAN programming language; SAINT; Supercomputer.

Autochrome plate

The invention: The first commercially successful process in which a single exposure in a regular camera produced a color image. The people behind the invention: Louis Lumière (1864-1948), a French inventor and scientist Auguste Lumière (1862-1954), an inventor, physician, physicist, chemist, and botanist Alphonse Seyewetz, a skilled scientist and assistant of the Lumière brothers Adding Color In 1882, Antoine Lumière, painter, pioneer photographer, and father of Auguste and Louis, founded a factory to manufacture photographic gelatin dry-plates. After the Lumière brothers took over the factory’s management, they expanded production to include roll film and printing papers in 1887 and also carried out joint research that led to fundamental discoveries and improvements in photographic development and other aspects of photographic chemistry. While recording and reproducing the actual colors of a subject was not possible at the time of photography’s inception (about 1822), the first practical photographic process, the daguerreotype, was able to render both striking detail and good tonal quality. Thus, the desire to produce full-color images, or some approximation to realistic color, occupied the minds of many photographers and inventors, including Louis and Auguste Lumière, throughout the nineteenth century. As researchers set out to reproduce the colors of nature, the first process that met with any practical success was based on the additive color theory expounded by the Scottish physicist James Clerk Maxwell in 1861. He believed that any color can be created by adding together red, green, and blue light in certain proportions. Maxwell, in his experiments, had taken three negatives through screens or filters of these additive primary colors. He then took slides made from these negatives and projected the slides through the same filters onto a screen so that their images were superimposed. As a result, he found that it was possible to reproduce the exact colors as well as the form of an object. Unfortunately, since colors could not be printed in their tonal relationships on paper before the end of the nineteenth century,Maxwell’s experiment was unsuccessful. Although Frederick E. Ives of Philadelphia, in 1892, optically united three transparencies so that they could be viewed in proper alignment by looking through a peephole, viewing the transparencies was still not as simple as looking at a black-and-white photograph. The Autochrome Plate The first practical method of making a single photograph that could be viewed without any apparatus was devised by John Joly of Dublin in 1893. Instead of taking three separate pictures through three colored filters, he took one negative through one filter minutely checkered with microscopic areas colored red, green, and blue. The filter and the plate were exactly the same size and were placed in contact with each other in the camera. After the plate was developed, a transparency was made, and the filter was permanently attached to it. The black-and-white areas of the picture allowed more or less light to shine through the filters; if viewed froma proper distance, the colored lights blended to form the various colors of nature. In sum, the potential principles of additive color and other methods and their potential applications in photography had been discovered and even experimentally demonstrated by 1880. Yet a practical process of color photography utilizing these principles could not be produced until a truly panchromatic emulsion was available, since making a color print required being able to record the primary colors of the light cast by the subject. Louis and Auguste Lumière, along with their research associate Alphonse Seyewetz, succeeded in creating a single-plate process based on this method in 1903. It was introduced commercially as the autochrome plate in 1907 and was soon in use throughout the world. This process is one of many that take advantage of the limited resolving power of the eye. Grains or dots too small to be recognized as separate units are accepted in their entirety and, to the sense of vision, appear as tones and continuous color.Impact While the autochrome plate remained one of the most popular color processes until the 1930’s, soon this process was superseded by subtractive color processes. Leopold Mannes and Leopold Godowsky, both musicians and amateur photographic researchers who eventually joined forces with Eastman Kodak research scientists, did the most to perfect the Lumière brothers’ advances in making color photography practical. Their collaboration led to the introduction in 1935 of Kodachrome, a subtractive process in which a single sheet of film is coated with three layers of emulsion, each sensitive to one primary color. A single exposure produces a color image. Color photography is now commonplace. The amateur market is enormous, and the snapshot is almost always taken in color. Commercial and publishing markets use color extensively. Even photography as an art form, which was done in black and white through most of its history, has turned increasingly to color.

Atomic-powered ship

The invention: The world’s first atomic-powered merchant ship demonstrated a peaceful use of atomic power. The people behind the invention: Otto Hahn (1879-1968), a German chemist Enrico Fermi (1901-1954), an Italian American physicist Dwight D. Eisenhower (1890-1969), president of the United States, 1953-1961 Splitting the Atom In 1938, Otto Hahn, working at the Kaiser Wilhelm Institute for Chemistry, discovered that bombarding uranium atoms with neutrons causes them to split into two smaller, lighter atoms. A large amount of energy is released during this process, which is called “fission.” When one kilogram of uranium is fissioned, it releases the same amount of energy as does the burning of 3,000 metric tons of coal. The fission process also releases new neutrons. Enrico Fermi suggested that these new neutrons could be used to split more uranium atoms and produce a chain reaction. Fermi and his assistants produced the first human-made chain reaction at the University of Chicago on December 2, 1942. Although the first use of this new energy source was the atomic bombs that were used to defeat Japan in World War II, it was later realized that a carefully controlled chain reaction could produce useful energy. The submarine Nautilus, launched in 1954, used the energy released from fission to make steam to drive its turbines. U.S. President Dwight David Eisenhower proposed his “Atoms for Peace” program in December, 1953. On April 25, 1955, President Eisenhower announced that the “Atoms for Peace” program would be expanded to include the design and construction of an atomicpowered merchant ship, and he signed the legislation authorizing the construction of the ship in 1956.Savannah’s Design and Construction A contract to design an atomic-powered merchant ship was awarded to George G. Sharp, Inc., on April 4, 1957. The ship was to carry approximately one hundred passengers (later reduced to sixty to reduce the ship’s cost) and 10,886 metric tons of cargo while making a speed of 21 knots, about 39 kilometers per hour. The ship was to be 181 meters long and 23.7 meters wide. The reactor was to provide steam for a 20,000-horsepower turbine that would drive the ship’s propeller. Most of the ship’s machinery was similar to that of existing ships; the major difference was that steam came from a reactor instead of a coal- or oil-burning boiler. New York Shipbuilding Corporation of Camden, New Jersey, won the contract to build the ship on November 16, 1957. States Marine Lines was selected in July, 1958, to operate the ship. It was christened Savannah and launched on July 21, 1959. The name Savannah was chosen to honor the first ship to use steam power while crossing an ocean. This earlier Savannah was launched in New York City in 1818. Ships are normally launched long before their construction is complete, and the new Savannah was no exception. It was finally turned over to States Marine Lines on May 1, 1962. After extensive testing by its operators and delays caused by labor union disputes, it began its maiden voyage from Yorktown, Virginia, to Savannah, Georgia, on August 20, 1962. The original budget for design and construction was $35 million, but by this time, the actual cost was about $80 million. Savannah‘s nuclear reactor was fueled with about 7,000 kilograms (15,400 pounds) of uranium. Uranium consists of two forms, or “isotopes.” These are uranium 235, which can fission, and uranium 238, which cannot. Naturally occurring uranium is less than 1 percent uranium 235, but the uranium in Savannah‘s reactor had been enriched to contain nearly 5 percent of this isotope. Thus, there was less than 362 kilograms of usable uranium in the reactor. The ship was able to travel about 800,000 kilometers on this initial fuel load. Three and a half million kilograms of water per hour flowed through the reactor under a pressure of 5,413 kilograms per square centimeter. It entered the reactor at 298.8 degrees Celsius and left at 317.7 degrees Celsius. Water leaving the reactor passed through a heat exchanger called a “steam generator.” In the steam generator, reactor water flowed through many small tubes. Heat passed through the walls of these tubes and boiled water outside them. About 113,000 kilograms of steam per hour were produced in this way at a pressure of 1,434 kilograms per square centimeter and a temperature of 240.5 degrees Celsius. Labor union disputes dogged Savannah‘s early operations, and it did not start its first trans-Atlantic crossing until June 8, 1964. Savannah was never a money maker. Even in the 1960’s, the trend was toward much bigger ships. It was announced that the ship would be retired in August, 1967, but that did not happen. It was finally put out of service in 1971. Later, Savannah was placed on permanent display at Charleston, South Carolina. Consequences Following the United States’ lead, Germany and Japan built atomic-powered merchant ships. The Soviet Union is believed to have built several atomic-powered icebreakers. Germany’s Otto Hahn, named for the scientist who first split the atom, began service in 1968, and Japan’s Mutsuai was under construction as Savannah retired. Numerous studies conducted in the early 1970’s claimed to prove that large atomic-powered merchant ships were more profitable than oil-fired ships of the same size. Several conferences devoted to this subject were held, but no new ships were built. Although the U.S. Navy has continued to use reactors to power submarines, aircraft carriers, and cruisers, atomic power has not been widely used for merchant-ship propulsion. Labor union problems such as those that haunted Savannah, high insurance costs, and high construction costs are probably the reasons. Public opinion, after the reactor accidents at Three Mile Island (in 1979) and Chernobyl (in 1986) is also a factor.

Atomic clock

The invention: A clock using the ammonia molecule as its oscillator that surpasses mechanical clocks in long-term stability, precision, and accuracy. The person behind the invention: Harold Lyons (1913-1984), an American physicist Time Measurement The accurate measurement of basic quantities, such as length, electrical charge, and temperature, is the foundation of science. The results of such measurements dictate whether a scientific theory is valid or must be modified or even rejected. Many experimental quantities change over time, but time cannot be measured directly. It must be measured by the occurrence of an oscillation or rotation, such as the twenty-four-hour rotation of the earth. For centuries, the rising of the Sun was sufficient as a timekeeper, but the need for more precision and accuracy increased as human knowledge grew. Progress in science can be measured by how accurately time has been measured at any given point. In 1713, the British government, after the disastrous sinking of a British fleet in 1707 because of a miscalculation of longitude, offered a reward of 20,000 pounds for the invention of a ship’s chronometer (a very accurate clock). Latitude is determined by the altitude of the Sun above the southern horizon at noon local time, but the determination of longitude requires an accurate clock set at Greenwich, England, time. The difference between the ship’s clock and the local sun time gives the ship’s longitude. This permits the accurate charting of new lands, such as those that were being explored in the eighteenth century. John Harrison, an English instrument maker, eventually built a chronometer that was accurate within one minute after five months at sea. He received his reward from Parliament in 1765. Atomic Clocks Provide Greater Stability A clock contains four parts: energy to keep the clock operating, an oscillator, an oscillation counter, and a display. A grandfather clock has weights that fall slowly, providing energy that powers the clock’s gears. The pendulum, a weight on the end of a rod, swings back and forth (oscillates) with a regular beat. The length of the rod determines the pendulum’s period of oscillation. The pendulum is attached to gears that count the oscillations and drive the display hands. There are limits to a mechanical clock’s accuracy and stability. The length of the rod changes as the temperature changes, so the period of oscillation changes. Friction in the gears changes as they wear out. Making the clock smaller increases its accuracy, precision, and stability. Accuracy is how close the clock is to telling the actual time. Stability indicates how the accuracy changes over time, while precision is the number of accurate decimal places in the display. A grandfather clock, for example, might be accurate to ten seconds per day and precise to a second, while having a stability of minutes per week. Applying an electrical signal to a quartz crystal will make the crystal oscillate at its natural vibration frequency, which depends on its size, its shape, and the way in which it was cut from the larger crystal. Since the faster a clock’s oscillator vibrates, the more precise the clock, a crystal-based clock is more precise than a large pendulum clock. By keeping the crystal under constant temperature, the clock is kept accurate, but it eventually loses its stability and slowly wears out. In 1948, Harold Lyons and his colleagues at the National Bureau of Standards (NBS) constructed the first atomic clock, which used the ammonia molecule as its oscillator. Such a clock is called an atomic clock because, when it operates, a nitrogen atom vibrates. The pyramid-shaped ammonia molecule is composed of a triangular base; there is a hydrogen atom at each corner and a nitrogen atom at the top of the pyramid. The nitrogen atom does not remain at the top; if it absorbs radio waves of the right energy and frequency, it passes through the base to produce an upside-down pyramid and then moves back to the top. This oscillation frequency occurs at 23,870 megacycles (1 megacycle equals 1 million cycles) per second. Lyons’s clock was actually a quartz-ammonia clock, since the signal from a quartz crystal produced radio waves of the crystal’s fre- quency that were fed into an ammonia-filled tube. If the radio waves were at 23,870 megacycles, the ammonia molecules absorbed the waves; a detector sensed this, and it sent no correction signal to the crystal. If radio waves deviated from 23,870 megacycles, the ammonia did not absorb them, the detector sensed the unabsorbed radio waves, and a correction signal was sent to the crystal. The atomic clock’s accuracy and precision were comparable to those of a quartz-based clock—one part in a hundred million—but the atomic clock was more stable because molecules do not wear out. The atomic clock’s accuracy was improved by using cesium 133 atoms as the source of oscillation. These atoms oscillate at 9,192,631,770 plus or minus 20 cycles per second. They are accurate to a billionth of a second per day and precise to nine decimal places. A cesium clock is stable for years. Future developments in atomic clocks may see accuracies of one part in a million billions. Impact The development of stable, very accurate atomic clocks has farreaching implications for many areas of science. Global positioning satellites send signals to receivers on ships and airplanes. By timing the signals, the receiver’s position is calculated to within several meters of its true location. Chemists are interested in finding the speed of chemical reactions, and atomic clocks are used for this purpose. The atomic clock led to the development of the maser (an acronym formicrowave amplification by stimulated emission of radiation), which is used to amplify weak radio signals, and the maser led to the development of the laser, a light-frequency maser that has more uses than can be listed here. Atomic clocks have been used to test Einstein’s theories of relativity that state that time on a moving clock, as observed by a stationary observer, slows down, and that a clock slows down near a large mass (because of the effects of gravity). Under normal conditions of low velocities and low mass, the changes in time are very small, but atomic clocks are accurate and stable enough to detect even these small changes. In such experiments, three sets of clocks were used—one group remained on Earth, one was flown west around the earth on a jet, and the last set was flown east. By comparing the times of the in-flight sets with the stationary set, the predicted slowdowns of time were observed and the theories were verified.

Atomic bomb

The invention: A weapon of mass destruction created during World War II that utilized nuclear fission to create explosions equivalent to thousands of tons of trinitrotoluene (TNT), The people behind the invention: J. Robert Oppenheimer (1904-1967), an American physicist Leslie Richard Groves (1896-1970), an American engineer and Army general Enrico Fermi (1900-1954), an Italian American nuclear physicist Niels Bohr (1885-1962), a Danish physicist Energy on a Large Scale The first evidence of uranium fission (the splitting of uranium atoms) was observed by German chemists Otto Hahn and Fritz Strassmann in Berlin at the end of 1938. When these scientists discovered radioactive barium impurities in neutron-irradiated uranium, they wrote to their colleague Lise Meitner in Sweden. She and her nephew, physicist Otto Robert Frisch, calculated the large release of energy that would be generated during the nuclear fission of certain elements. This result was reported to Niels Bohr in Copenhagen. Meanwhile, similar fission energies were measured by Frédéric Joliot and his associates in Paris, who demonstrated the release of up to three additional neutrons during nuclear fission. It was recognized immediately that if neutron-induced fission released enough additional neutrons to cause at least one more such fission, a selfsustaining chain reaction would result, yielding energy on a large scale. While visiting the United States from January to May of 1939, Bohr derived a theory of fission with John Wheeler of Princeton University. This theory led Bohr to predict that the common isotope uranium 238 (which constitutes 99.3 percent of naturally occurring uranium) would require fast neutrons for fission, but that the rarer uranium 235 would fission with neutrons of any energy. This meant that uranium 235 would be far more suitable for use in any sort of bomb. Uranium bombardment in a cyclotron led to the discovery of plutonium in 1940 and the discovery that plutonium 239 was fissionable— and thus potentially good bomb material. Uranium 238 was then used to “breed” (create) plutonium 239, which was then separated from the uranium by chemical methods. During 1942, the Manhattan District of the Army Corps of Engineers was formed under General Leslie Richard Groves, an engineer and Army general who contracted with E. I. Du Pont de Nemours and Company to construct three secret atomic cities at a total cost of $2 billion. At Oak Ridge, Tennessee, twenty-five thousand workers built a 1,000-kilowatt reactor as a pilot plant.Asecond city of sixty thousand inhabitants was built at Hanford, Washington, where three huge reactors and remotely controlled plutoniumextraction plants were completed in early 1945. A Sustained and Awesome Roar Studies of fast-neutron reactions for an atomic bomb were brought together in Chicago in June of 1942 under the leadership of J. Robert Oppenheimer. He soon became a personal adviser to Groves, who built for Oppenheimer a laboratory for the design and construction of the bomb at Los Alamos, New Mexico. In 1943, Oppenheimer gathered two hundred of the best scientists in what was by now being called the Manhattan Project to live and work in this third secret city. Two bomb designs were developed. A gun-type bomb called “Little Boy” used 15 kilograms of uranium 235 in a 4,500-kilogram cylinder about 2 meters long and 0.5 meter in diameter, in which a uranium bullet could be fired into three uranium target rings to form a critical mass. An implosion-type bomb called “Fat Man” had a 5-kilogram spherical core of plutonium about the size of an orange, which could be squeezed inside a 2,300-kilogram sphere about 1.5 meters in diameter by properly shaped explosives to make the mass critical in the shorter time required for the faster plutonium fission process. A flat scrub region 200 kilometers southeast of Alamogordo, called Trinity, was chosen for the test site, and observer bunkers were built about 10 kilometers from a 30-meter steel tower. On July 13, 1945, one of the plutonium bombs was assembled at the site; the next morning, it was raised to the top of the tower. Two days later, on July 16, after a short thunderstorm delay, the bomb was detonated at 5:30 a.m. The resulting implosion initiated a chain reaction of nearly 60 fission generations in about a microsecond. It produced an intense flash of light and a fireball that expanded to a diameter of about 600 meters in two seconds, rose to a height of more than 12 kilometers, and formed an ominous mushroom shape. Forty seconds later, an air blast hit the observer bunkers, followed by a sustained and awesome roar. Measurements confirmed that the explosion had the power of 18.6 kilotons of trinitrotoluene (TNT), nearly four times the predicted value. Impact On March 9, 1945, 325 American B-29 bombers dropped 2,000 tons of incendiary bombs on Tokyo, resulting in 100,000 deaths from the fire storms that swept the city. Nevertheless, the Japanese military refused to surrender, and American military plans called for an invasion of Japan, with estimates of up to a half million American casualties, plus as many as 2 million Japanese casualties. On August 6, 1945, after authorization by President Harry S. Truman, the B-29 Enola Gay dropped the uranium Little Boy bomb on Hiroshima at 8:15 a.m. On August 9, the remaining plutonium Fat Man bomb was dropped on Nagasaki. Approximately 100,000 people died at Hiroshima (out of a population of 400,000), and about 50,000 more died at Nagasaki. Japan offered to surrender on August 10, and after a brief attempt by some army officers to rebel, an official announcement by Emperor Hirohito was broadcast on August 15. The development of the thermonuclear fusion bomb, in which hydrogen isotopes could be fused together by the force of a fission explosion to produce helium nuclei and almost unlimited energy, had been proposed early in the Manhattan Project by physicist Edward Teller. Little effort was invested in the hydrogen bomb until after the surprise explosion of a Soviet atomic bomb in September, 1949, which had been built with information stolen from the Manhattan Project. After three years of development under Teller’s guidance, the first successful H-bomb was exploded on November 1, 1952, obliterating the Elugelab atoll in the Marshall Islands of the South Pacific. The arms race then accelerated until each side had stockpiles of thousands of H-bombs. The Manhattan Project opened a Pandora’s box of nuclear weapons that would plague succeeding generations, but it contributed more than merely weapons. About 19 percent of the electrical energy in the United States is generated by about 110 nuclear reactors producing more than 100,000 megawatts of power. More than 400 reactors in thirty countries provide 300,000 megawatts of the world’s power. Reactors have made possible the widespread use of radioisotopes in medical diagnosis and therapy. Many of the techniques for producing and using these isotopes were developed by the hundreds of nuclear physicists who switched to the field of radiation biophysics after the war, ensuring that the benefits of their wartime efforts would reach the public.

Assembly line

The invention: Amanufacturing technique pioneered in the automobile industry by Henry Ford that lowered production costs and helped bring automobile ownership within the reach of millions of Americans in the early twentieth century. The people behind the invention: Henry Ford (1863-1947), an American carmaker Eli Whitney (1765-1825), an American inventor Elisha King Root (1808-1865), the developer of division of labor Oliver Evans (1755-1819), the inventor of power conveyors Frederick Winslow Taylor (1856-1915), an efficiency engineer A Practical Man Henry Ford built his first “horseless carriage” by hand in his home workshop in 1896. In 1903, the Ford Motor Company was born. Ford’s first product, the Model A, sold for less than one thousand dollars, while other cars at that time were priced at five to ten thousand dollars each. When Ford and his partners tried, in 1905, to sell a more expensive car, sales dropped. Then, in 1907, Ford decided that the Ford Motor Company would build “a motor car for the great multitude.” It would be called the Model T. The Model T came out in 1908 and was everything that Henry Ford said it would be. Ford’s Model T was a low-priced (about $850), practical car that came in one color only: black. In the twenty years during which the Model T was built, the basic design never changed. Yet the price of the Model T, or “Tin Lizzie,” as it was affectionately called, dropped over the years to less than half that of the original Model T. As the price dropped, sales increased, and the Ford Motor Company quickly became the world’s largest automobile manufacturer. The last of more than 15 million Model T’s was made in 1927. Although it looked and drove almost exactly like the first Model T, these two automobiles were built in an entirely different way. The first was custom-built, while the last came off an assembly line. At first, Ford had built his cars in the same way everyone else did: one at a time. Skilled mechanics would work on a car from start to finish, while helpers and runners brought parts to these highly paid craftsmen as they were needed. After finishing one car, the mechanics and their helpers would begin the next. The Quest for Efficiency Custom-built products are good when there is little demand and buyers are willing to pay the high labor costs. This was not the case with the automobile. Ford realized that in order to make a large number of quality cars at a low price, he had to find a more efficient way to build cars. To do this, he looked to the past and the work of others. He found four ideas: interchangeable parts, continuous flow, division of labor, and elimination of wasted motion. Eli Whitney, the inventor of the cotton gin, was the first person to use interchangeable parts successfully in mass production. In 1798, the United States government asked Whitney to make several thousand muskets in two years. Instead of finding and hiring gunsmiths to make the muskets by hand, Whitney used most of his time and money to design and build special machines that could make large numbers of identical parts—one machine for each part that was needed to build a musket. These tools, and others Whitney made for holding, measuring, and positioning the parts, made it easy for semiskilled, and even unskilled, workers to build a large number of muskets. Production can be made more efficient by carefully arranging the different stages of production to create a “continuous flow.” Ford borrowed this idea from at least two places: the meat-packing houses of Chicago and an automatic grain mill run by Oliver Evans. Ford’s idea for a moving assembly line came from Chicago’s great meat-packing houses in the late 1860’s. Here, the bodies of animals were moved along an overhead rail past a number of workers, each ofwhommade a certain cut, or handled one part of the packing job. This meant that many animals could be butchered and packaged in a single day. Ford looked to Oliver Evans for an automatic conveyor system. In 1783, Evans had designed and operated an automatic grain mill that could be run by only two workers. As one worker poured grain into a funnel-shaped container, called a “hopper,” at one end of the mill, a second worker filled sacks with flour at the other end. Everything in between was done automatically, as Evans’s conveyors passed the grain through the different steps of the milling process without any help. The idea of “division of labor” is simple: When one complicated job is divided into several easier jobs, some things can be made faster, with fewer mistakes, by workers who need fewer skills than ever before. Elisha King Root had used this principle to make the famous Colt “Six-Shooter.” In 1849, Root went to work for Samuel Colt at his Connecticut factory and proved to be a manufacturing genius. By dividing the work into very simple steps, with each step performed by one worker, Root was able to make many more guns in much less time. Before Ford applied Root’s idea to the making of engines, it took one worker one day to make one engine. By breaking down the complicated job of making an automobile engine into eighty-four simpler jobs, Ford was able to make the process much more efficient. By assigning one person to each job, Ford’s company was able to make 352 engines per day—an increase of more than 400 percent. Frederick Winslow Taylor has been called the “original efficiency expert.” His idea was that inefficiency was caused by wasted time and wasted motion. So Taylor studied ways to eliminate wasted motion. He proved that, in the long run, doing a job too quickly was as bad as doing it too slowly. “Correct speed is the speed at which men can work hour after hour, day after day, year in and year out, and remain continuously in good health,” he said. Taylor also studied ways to streamline workers’ movements. In this way, he was able to keep wasted motion to a minimum. Impact The changeover from custom production to mass production was an evolution rather than a revolution. Henry Ford applied the four basic ideas of mass production slowly and with care, testing each new idea before it was used. In 1913, the first moving assembly line for automobiles was being used to make Model T’s. Ford was able to make his Tin Lizzies faster than ever, and his competitors soon followed his lead. He had succeeded in making it possible for millions of people to buy automobiles. Ford’s work gave a new push to the Industrial Revolution. It showed Americans that mass production could be used to improve quality, cut the cost of making an automobile, and improve profits. In fact, the Model T was so profitable that in 1914 Ford was able to double the minimum daily wage of his workers, so that they too could afford to buy Tin Lizzies. Although Americans account for only about 6 percent of the world’s population, they now own about 50 percent of its wealth. There are more than twice as many radios in the United States as there are people. The roads are crowded with more than 180 million automobiles. Homes are filled with the sounds and sights emitting from more than 150 million television sets. Never have the people of one nation owned so much. Where did all the products—radios, cars, television sets—come from? The answer is industry, which still depends on the methods developed by Henry Ford.

Aspartame

The invention An artificial sweetener with a comparatively natural taste widely used in carbonated beverages. The people behind the invention Arthur H. Hayes, Jr. (1933- ), a physician and commissioner of the U.S. Food and Drug Administration (FDA) James M. Schlatter (1942- ), an American chemist Michael Sveda (1912- ), an American chemist and inventor Ludwig Frederick Audrieth (1901- ), an American chemist and educator Ira Remsen (1846-1927), an American chemist and educator Constantin Fahlberg (1850-1910), a German chemist. Sweetness Without Calories People have sweetened food and beverages since before recorded history. The most widely used sweetener is sugar, or sucrose. The only real drawback to the use of sucrose is that it is a nutritive sweetener: In addition to adding a sweet taste, it adds calories. Because sucrose is readily absorbed by the body, an excessive amount can be life-threatening to diabetics. This fact alone would make the development of nonsucrose sweeteners attractive. There are three common nonsucrose sweeteners in use around the world: saccharin, cyclamates, and aspartame. Saccharin was the first of this group to be discovered, in 1879. Constantin Fahlberg synthesized saccharin based on the previous experimental work of Ira Remsen using toluene (derived from petroleum). This product was found to be three hundred to five hundred times as sweet as sugar, although some people could detect a bitter aftertaste. In 1944, the chemical family of cyclamates was discovered by Ludwig Frederick Audrieth and Michael Sveda. Although these compounds are only thirty to eighty times as sweet as sugar, there was no detectable aftertaste. By the mid-1960’s, cyclamates had resplaced saccharin as the leading nonnutritive sweetener in theUnited States. Although cyclamates are still in use throughout the world, in October, 1969, FDA removed them from the list of approved food additives because of tests that indicated possible health hazards. A Political Additive Aspartame is the latest in artificial sweeteners that are derived from natural ingredients—in this case, two amino acids, one from milk and one from bananas. Discovered by accident in 1965 by American chemist James M. Schlatter when he licked his fingers during an experiment, aspartame is 180 times as sweet as sugar. In 1974, the FDAapproved its use in dry foods such as gum and cerealand as a sugar replacement. Shortly after its approval for this limited application, the FDA held public hearings on the safety concerns raised by JohnW. Olney, a professor of neuropathology at Washington University in St. Louis. There was some indication that aspartame, when combined with the common food additive monosodium glutamate, caused brain damage in children. These fears were confirmed, but the risk of brain damage was limited to a small percentage of individuals with a rare genetic disorder. At this point, the public debate took a political turn: Senator William Proxmire charged FDA Commissioner AlexanderM. Schmidt with public misconduct. This controversy resulted in aspartame being taken off the market in 1975. In 1981, the new FDA commissioner, Arthur H. Hayes, Jr., resapproved aspartame for use in the same applications: as a tabletop sweetener, as a cold-cereal additive, in chewing gum, and for other miscellaneous uses. In 1983, the FDAapproved aspartame for use in carbonated beverages, its largest application to date. Later safety studies revealed that children with a rare metabolic disease, phenylketonuria,could not ingest this sweetener without severe health risks because of the presence of phenylalanine in aspartame. This condition results in a rapid buildup in phenylalanine in the blood. Laboratories simulated this condition in rats and found that high doses of aspartame inhibited the synthesis of dopamine, a neurotransmitter. Once this happens, an increase in the frequency of seizures can occur. There was no direct evidence, however, that aspartame actually caused seizures in these experiments. Many other compounds are being tested for use as sugar replacements, the sweetest being a relative of aspartame. This compound is seventeen thousand to fifty-two thousand times sweeter than sugar. Impact The business fallout from the approval of a new low-calorie sweetener occurred over a short span of time. In 1981, sales of thisartificial sweetener by G. D. Searle and Company were $74 million. In 1983, sales rose to $336 million and exceeded half a billion dollars the following year. These figures represent sales of more than 2,500tons of this product. In 1985, 3,500 tons of aspartame were consumed. Clearly, this product’s introduction was a commercial success for Searle. During this same period, the percentage of reduced calorie carbonated beverages containing saccharin declined from100 percent to 20 percent in an industry that had $4 billion in sales. Universally, consumers preferred products containing aspartame; the bitter aftertaste of saccharin was rejected in favor of the new, less powerful sweetener. There is a trade-off in using these products. The FDA found evidence linking both saccharin and cyclamates to an elevated incidence of cancer. Cyclamates were banned in the United States for this reason. Public resistance to this measure caused the agency to back away from its position. The rationale was that, compared toother health risks associated with the consumption of sugar (especially for diabetics and overweight persons), the chance of getting cancer was slight and therefore a risk that many people wouldchoose to ignore. The total domination of aspartame in the sweetener market seems to support this assumption.