Math Is Fun Forum
  Discussion about math, puzzles, games and fun.   Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ • π ƒ -¹ ² ³ °

You are not logged in.

#1 Re: Ganesh's Puzzles » Oral puzzles » Today 12:48:58

Hi bobbym,

The two solutions in #2618 are correct! Brilliant!

#2619. Find the missing frequencies in the following distribution if it is known that the mean of the frequency is 1.46.

Number of accidents (x)   :   0     :     1     :     2      :      3      :     4      :     5     :      Total     
Frequency (f)                  :   46    :    ?      :     ?      :      25    :     10    :     5      :      200

#2 Re: Ganesh's Puzzles » English language puzzles » Today 12:24:11

Hi bobbym,

The Answer #2191 is well attempted! Good work!

#2193. What does the noun atoll mean?

#2194. What does the noun atomizer mean?

#3 Re: Ganesh's Puzzles » General Quiz » Today 12:07:06

Hi bobbym,

Good attempt, bobbym! (#5691)

#5693. What does the Latin expression / phrase sine die mean/?

#5694. What does the Latin expression  / phrase persona non grata mean?

#4 Re: Ganesh's Puzzles » English language puzzles » Today 03:06:37

Hi bobbym,

The Answer #1041 is correct! Excellent!

#2191. (revised #)  What does the noun Atkins diet mean?

#2192. What does the noun atonement mean?

#5 Re: Dark Discussions at Cafe Infinity » crème de la crème » Today 01:24:05

23. Socrates

Philosopher (c. 470 BCE–c. 399 BCE)
Place of Birth : Athens, Greece
Place of Death : Athens, Greece

Socrates was a Greek philosopher and the main source of Western thought. Little is known of his life except what was recorded by his students, including Plato.

Socrates was born circa 470 BC, in Athens, Greece. We know of his life through the writings of his students, including Plato and Xenophon. His "Socratic method," laid the groundwork for Western systems of logic and philosophy. When the political climate of Greece turned, Socrates was sentenced to death by hemlock poisoning in 399 BC. He accepted this judgment rather than fleeing into exile.

Early Years

Born circa 470 BC in Athens, Greece, Socrates's life is chronicled through only a few sources—the dialogues of Plato and Xenophon and the plays of Aristophanes. Because these writings had other purposes than reporting his life, it is likely none present a completely accurate picture. However, collectively, they provide a unique and vivid portrayal of Socrates's philosophy and personality.
Socrates was the son of Sophroniscus, an Athenian stone mason and sculptor, and Phaenarete, a midwife. Because he wasn't from a noble family, he probably received a basic Greek education and learned his father's craft at a young age. It is believed Socrates worked as mason for many years before he devoted his life to philosophy. Contemporaries differ in their account of how Socrates supported himself as a philosopher. Both Xenophon and Aristophanes state Socrates received payment for teaching, while Plato writes Socrates explicitly denied accepting payment, citing his poverty as proof.

Socrates married Xanthippe, a younger woman, who bore him three sons—Lamprocles, Sophroniscus and Menexenus. There is little known about her except for Xenophon's characterization of Xanthippe as "undesirable." He writes she was not happy with Socrates's second profession and complained that he wasn’t supporting family as a philosopher. By his own words, Socrates had little to do with his sons' upbringing and expressed far more interest in the intellectual development of Athens' young boys.

Athenian law required all able bodied males serve as citizen soldiers, on call for duty from ages 18 until 60. According to Plato, Socrates served in the armored infantry—known as the hoplite—with shield, long spear and face mask. He participated in three military campaigns during the Peloponnesian War, at Delium, Amphipolis, and Potidaea, where he saved the life of Alcibiades, a popular Athenian general. Socrates was known for his courage in battle and fearlessness, a trait that stayed with him throughout his life. After his trial, he compared his refusal to retreat from his legal troubles to a soldier's refusal to retreat from battle when threatened with death.
Plato's Symposium provides the best details of Socrates's physical appearance. He was not the ideal of Athenian masculinity. Short and stocky, with a snub nose and bulging eyes, Socrates always seemed to appear to be staring. However, Plato pointed out that in the eyes of his students, Socrates possessed a different kind of attractiveness, not based on a physical ideal but on his brilliant debates and penetrating thought. Socrates always emphasized the importance of the mind over the relative unimportance of the human body. This credo inspired Plato’s philosophy of dividing reality into two separate realms, the world of the senses and the world of ideas, declaring that the latter was the only important one.

Socrates believed that philosophy should achieve practical results for the greater well-being of society. He attempted to establish an ethical system based on human reason rather than theological doctrine. He pointed out that human choice was motivated by the desire for happiness. Ultimate wisdom comes from knowing oneself. The more a person knows, the greater his or her ability to reason and make choices that will bring true happiness. Socrates believed that this translated into politics with the best form of government being neither a tyranny nor a democracy. Instead, government worked best when ruled by individuals who had the greatest ability, knowledge, and virtue and possessed a complete understanding of themselves.
For Socrates, Athens was a classroom and he went about asking questions of the elite and common man alike, seeking to arrive at political and ethical truths. Socrates didn’t lecture about what he knew. In fact, he claimed to be ignorant because he had no ideas, but wise because he recognized his own ignorance. He asked questions of his fellow Athenians in a dialectic method (the Socratic Method) which compelled the audience to think through a problem to a logical conclusion. Sometimes the answer seemed so obvious, it made Socrates's opponents look foolish. For this, he was admired by some and vilified by others.

During Socrates's life, Athens was going through a dramatic transition from hegemony in the classical world to its decline after a humiliating defeat by Sparta in the Peloponnesian War. Athenians entered a period of instability and doubt about their identity and place in the world. As a result, they clung to past glories, notions of wealth, and a fixation with physical beauty. Socrates attacked these values with his insistent emphasis on the greater importance of the mind. While many Athenians admired Socrates's challenges to Greek conventional wisdom and the humorous way he went about it, an equal number grew angry and felt he threatened their way of life and uncertain future.


The jury was not swayed by Socrates's defense and convicted him by a vote of 280 to 221. Possibly the defiant tone of his defense contributed to the verdict and he made things worse during the deliberation over his punishment. Athenian law allowed a convicted citizen to propose an alternative punishment to the one called for by the prosecution and the jury would decide. Instead of proposing he be exiled, Socrates suggested he be honored by the city for his contribution to their enlightenment and be paid for his services. The jury was not amused and sentenced him to death by drinking a mixture of poison hemlock.
Before Socrates's execution, friends offered to bribe the guards and rescue him so he could flee into exile. He declined, stating he wasn't afraid of death, felt he would be no better off if in exile and said he was still a loyal citizen of Athens, willing to abide by its laws, even the ones that condemned him to death. Plato described Socrates's execution in his Phaedo dialogue: Socrates drank the hemlock mixture without hesitation. Numbness slowly crept into his body until it reached his heart. Shortly before his final breath, Socrates described his death as a release of the soul from the body.


#7 Re: Ganesh's Puzzles » Doc, Doc! » Yesterday 22:40:38

Hi bobbym,

Wonderful, bobbym!

#1043. What does TS signify in medical science? A condition in which a female is partly or completely missing an X chromosome. Signs and symptoms vary among those affected. Often, a short and webbed neck, low-set ears, low hairline at the back of the neck, short stature, and swollen hands and feet are seen at birth. Heart defects, diabetes, and low thyroid hormone occur more frequently. Most people with TS have normal intelligence. Many, however, have troubles with spatial visualization such as that needed for mathematics. Vision and hearing problems occur more often. It is not usually inherited from a person's parents. No environmental risks are known and the mother's age does not play a role. It is due to a chromosomal abnormality in which all or part of one of the X chromosomes is missing or altered. While most people have 46 chromosomes, people with TS usually have 45.

#8 Re: Ganesh's Puzzles » Oral puzzles » Yesterday 22:18:55

Hi bobbym,

The solution #2617 is correct! Brilliant!

#2618. Evaluate:

#9 Re: Ganesh's Puzzles » Series and Progressions » Yesterday 22:06:48

Hi bobbym,

The solution SP # 136 (two parts) are correct! Excellent!

SP # Find the total volume of 15 cubes whose edges are 16 cm, 17 cm, 18 cm, ......., and 30 cm respectively.

#10 Re: Ganesh's Puzzles » Mensuration » Yesterday 21:55:44

Hi bobbym,

The solution M # 127 is correct! Excellent!

M # 128. A race track is in the form of a ring whose inner circumference is 352 meters, and the outer circumference is 396 meters. Find the width of the track.

#11 Re: Ganesh's Puzzles » Doc, Doc! » Yesterday 19:45:46

Hi bobbym,

The Answer #1041 (varicella) is correct! Excellent!

#1042. What is  Van den Bergh reaction?

#12 Re: Ganesh's Puzzles » Doc, Doc! » Yesterday 19:15:30

Hi bobbym,

#1041. What does the medical term ''varicella'' signify?

#13 Re: Ganesh's Puzzles » 10 second questions » Yesterday 17:22:50

Hi bobbym,

The solution #5551 is perfect! Brilliant!

#5552. If

is an acute angle and
, find the value of

#14 Re: Ganesh's Puzzles » General Quiz » Yesterday 17:14:17

Hi bobbym,

#5691. What does the abbreviation PTBT signify? (in connection with nuclear weapons)

#5692. Q.E.D. is an initialism of the Latin phrase quod erat demonstrandum, meaning "which is what had to be proven". The phrase is traditionally placed in its abbreviated form at the end of a mathematical proof or philosophical argument when what was specified in the enunciation—and in the setting-out—has been exactly restated as the conclusion of the demonstration. The abbreviation thus signals the completion of the proof.
What do the abbreviations Q.E.F. and Q.E.I  signify?

#15 Re: Ganesh's Puzzles » General Quiz » Yesterday 01:24:10

Hi bobbym,

The Answers #5688 is correct! Excellent!

#5689.  Name the British Marxist historian (9 June 1917 – 1 October 2012) of the rise of industrial capitalism, socialism, and nationalism. His best-known works include his trilogy about what he called the "long 19th century" (The Age of Revolution: Europe 1789–1848, The Age of Capital: 1848–1875 and The Age of Empire: 1875–1914), The Age of Extremes on the short 20th century, and an edited volume that introduced the influential idea of "invented traditions".

#5690. Name the author  (6 March 1927 – 17 April 2014) :  Colombian novelist, short-story writer, screenwriter and journalist, known affectionately as Gabo or Gabito throughout Latin America. 'One Hundred Years of Solitude' is a 1967 novel by Colombian author that tells the multi-generational story of the Buendía family, whose patriarch, José Arcadio Buendía, founds the town of Macondo, the metaphoric Colombia. The magical realist style and thematic substance of One Hundred Years of Solitude established it as an important, representative novel of the literary Latin American Boom of the 1960s and 1970s, which was stylistically influenced by Modernism (European and North American) and the Cuban Vanguardia (Avant-Garde) literary movement. 'One Hundred Years of Solitude' was first published in Spanish in 1967; it has subsequently has been translated into thirty-seven languages and has sold more than 30 million copies. The novel remains widely acclaimed today, and is considered by many to be his masterpiece.

#16 Re: Ganesh's Puzzles » Doc, Doc! » Yesterday 00:34:49

Hi bobbym,

#1040. Name the chemical -  An inorganic compound that is used as a food additive. The additive is often employed by fast food chains to absorb fatty acids and remove impurities that form in edible oils during the frying process.  It can be used as an antacid in the treatment of peptic ulcers. It increases the pH of gastric juice via a neutralisation reaction. It also precipitates colloidal silica, which can coat gastrointestinal mucosa conferring further protection. It can also be used in oral pharmaceutical formulations and food products as a glidant. It is also used therapeutically as an antacid, and also for the treatment of ciprofloxacin overdose or toxicity.

#17 Re: Ganesh's Puzzles » English language puzzles » Yesterday 00:19:48

Hi bobbym,

Both the Answers, #1039 and #1040, are correct! Excellent!

#1041. What does the adjective atavistic mean?

#1042. What does the noun atelier mean?

#18 Re: Ganesh's Puzzles » Oral puzzles » 2015-11-27 20:19:53

Hi bobbym,

The solutions (two parts) in #2616 are correct! Good work!

#2617. Find the value of 'k' for the the given equation has real and equal root:


#19 Re: Ganesh's Puzzles » 10 second questions » 2015-11-27 20:09:14

Hi bobbym,

The solution #5550 is correct! Stupendous!

#5551. Seven years ago, Varun's age was five times the square of Swati's age. Three years hence, Swati's age will be two fifth of Varun's age. Find their present ages.

#20 Re: Dark Discussions at Cafe Infinity » crème de la crème » 2015-11-27 17:57:46

22. Thomas Edison

Thomas Alva Edison,  (born February 11, 1847, Milan, Ohio, U.S.—died October 18, 1931, West Orange, New Jersey), American inventor who, singly or jointly, held a world record 1,093 patents. In addition, he created the world’s first industrial research laboratory.

Edison was the quintessential American inventor in the era of Yankee ingenuity. He began his career in 1863, in the adolescence of the telegraph industry, when virtually the only source of electricity was primitive batteries putting out a low-voltage current. Before he died, in 1931, he had played a critical role in introducing the modern age of electricity. From his laboratories and workshops emanated the phonograph, the carbon-button transmitter for the telephone speaker and microphone, the incandescent lamp, a revolutionary generator of unprecedented efficiency, the first commercial electric light and power system, an experimental electric railroad, and key elements of motion-picture apparatus, as well as a host of other inventions.

Edison was the seventh and last child—the fourth surviving—of Samuel Edison, Jr., and Nancy Elliot Edison. At an early age he developed hearing problems, which have been variously attributed but were most likely due to a familial tendency to mastoiditis. Whatever the cause, Edison’s deafness strongly influenced his behaviour and career, providing the motivation for many of his inventions.

Early years

In 1854 Samuel Edison became the lighthouse keeper and carpenter on the Fort Gratiot military post near Port Huron, Michigan, where the family lived in a substantial home. Alva, as the inventor was known until his second marriage, entered school there and attended sporadically for five years. He was imaginative and inquisitive, but because much instruction was by rote and he had difficulty hearing, he was bored and was labeled a misfit. To compensate, he became an avid and omnivorous reader. Edison’s lack of formal schooling was not unusual. At the time of the Civil War the average American had attended school a total of 434 days—little more than two years’ schooling by today’s standards.

In 1859 Edison quit school and began working as a trainboy on the railroad between Detroit and Port Huron. Four years earlier, the Michigan Central had initiated the commercial application of the telegraph by using it to control the movement of its trains, and the Civil War brought a vast expansion of transportation and communication. Edison took advantage of the opportunity to learn telegraphy and in 1863 became an apprentice telegrapher.

Messages received on the initial Morse telegraph were inscribed as a series of dots and dashes on a strip of paper that was decoded and read, so Edison’s partial deafness was no handicap. Receivers were increasingly being equipped with a sounding key, however, enabling telegraphers to “read” messages by the clicks. The transformation of telegraphy to an auditory art left Edison more and more disadvantaged during his six-year career as an itinerant telegrapher in the Midwest, the South, Canada, and New England. Amply supplied with ingenuity and insight, he devoted much of his energy toward improving the inchoate equipment and inventing devices to facilitate some of the tasks that his physical limitations made difficult. By January 1869 he had made enough progress with a duplex telegraph (a device capable of transmitting two messages simultaneously on one wire) and a printer, which converted electrical signals to letters, that he abandoned telegraphy for full-time invention and entrepreneurship.

Edison moved to New York City, where he initially went into partnership with Frank L. Pope, a noted electrical expert, to produce the Edison Universal Stock Printer and other printing telegraphs. Between 1870 and 1875 he worked out of Newark, New Jersey, and was involved in a variety of partnerships and complex transactions in the fiercely competitive and convoluted telegraph industry, which was dominated by the Western Union Telegraph Company. As an independent entrepreneur he was available to the highest bidder and played both sides against the middle. During this period he worked on improving an automatic telegraph system for Western Union’s rivals. The automatic telegraph, which recorded messages by means of a chemical reaction engendered by the electrical transmissions, proved of limited commercial success, but the work advanced Edison’s knowledge of chemistry and laid the basis for his development of the electric pen and mimeograph, both important devices in the early office machine industry, and indirectly led to the discovery of the phonograph. Under the aegis of Western Union he devised the quadruplex, capable of transmitting four messages simultaneously over one wire, but railroad baron and Wall Street financier Jay Gould, Western Union’s bitter rival, snatched the quadruplex from the telegraph company’s grasp in December 1874 by paying Edison more than $100,000 in cash, bonds, and stock, one of the larger payments for any invention up to that time. Years of litigation followed.

Menlo Park

Although Edison was a sharp bargainer, he was a poor financial manager, often spending and giving away money more rapidly than he earned it. In 1871 he married 16-year-old Mary Stilwell, who was as improvident in household matters as he was in business, and before the end of 1875 they were in financial difficulties. To reduce his costs and the temptation to spend money, Edison brought his now-widowed father from Port Huron to build a 2 1/2-story laboratory and machine shop in the rural environs of Menlo Park, New Jersey—12 miles south of Newark—where he moved in March 1876. Accompanying him were two key associates, Charles Batchelor and John Kruesi. Batchelor, born in Manchester in 1845, was a master mechanic and draftsman who complemented Edison perfectly and served as his “ears” on such projects as the phonograph and telephone. He was also responsible for fashioning the drawings that Kruesi, a Swiss-born machinist, translated into models.

Edison experienced his finest hours at Menlo Park. While experimenting on an underwater cable for the automatic telegraph, he found that the electrical resistance and conductivity of carbon (then called plumbago) varied according to the pressure it was under. This was a major theoretical discovery, which enabled Edison to devise a “pressure relay” using carbon rather than the usual magnets to vary and balance electric currents. In February 1877 Edison began experiments designed to produce a pressure relay that would amplify and improve the audibility of the telephone, a device that Edison and others had studied but which Alexander Graham Bell was the first to patent, in 1876. By the end of 1877 Edison had developed the carbon-button transmitter that is still used in telephone speakers and microphones.

The phonograph

Edison invented many items, including the carbon transmitter, in response to specific demands for new products or improvements. But he also had the gift of serendipity: when some unexpected phenomenon was observed, he did not hesitate to halt work in progress and turn off course in a new direction. This was how, in 1877, he achieved his most original discovery, the phonograph. Because the telephone was considered a variation of acoustic telegraphy, Edison during the summer of 1877 was attempting to devise for it, as he had for the automatic telegraph, a machine that would transcribe signals as they were received, in this instance in the form of the human voice, so that they could then be delivered as telegraph messages. (The telephone was not yet conceived as a general, person-to-person means of communication.) Some earlier researchers, notably the French inventor Léon Scott, had theorized that each sound, if it could be graphically recorded, would produce a distinct shape resembling shorthand, or phonography (“sound writing”), as it was then known. Edison hoped to reify this concept by employing a stylus-tipped carbon transmitter to make impressions on a strip of paraffined paper. To his astonishment, the scarcely visible indentations generated a vague reproduction of sound when the paper was pulled back beneath the stylus.

Edison unveiled the tinfoil phonograph, which replaced the strip of paper with a cylinder wrapped in tinfoil, in December 1877. It was greeted with incredulity. Indeed, a leading French scientist declared it to be the trick device of a clever ventriloquist. The public’s amazement was quickly followed by universal acclaim. Edison was projected into worldwide prominence and was dubbed the Wizard of Menlo Park, although a decade passed before the phonograph was transformed from a laboratory curiosity into a commercial product.

The electric light

Another offshoot of the carbon experiments reached fruition sooner. Samuel Langley, Henry Draper, and other American scientists needed a highly sensitive instrument that could be used to measure minute temperature changes in heat emitted from the Sun’s corona during a solar eclipse along the Rocky Mountains on July 29, 1878. To satisfy those needs Edison devised a “microtasimeter” employing a carbon button. This was a time when great advances were being made in electric arc lighting, and during the expedition, which Edison accompanied, the men discussed the practicality of “subdividing” the intense arc lights so that electricity could be used for lighting in the same fashion as with small, individual gas “burners.” The basic problem seemed to be to keep the burner, or bulb, from being consumed by preventing it from overheating. Edison thought he would be able to solve this by fashioning a microtasimeter-like device to control the current. He boldly announced that he would invent a safe, mild, and inexpensive electric light that would replace the gaslight.

The incandescent electric light had been the despair of inventors for 50 years, but Edison’s past achievements commanded respect for his boastful prophecy. Thus, a syndicate of leading financiers, including J.P. Morgan and the Vanderbilts, established the Edison Electric Light Company and advanced him $30,000 for research and development. Edison proposed to connect his lights in a parallel circuit by subdividing the current, so that, unlike arc lights, which were connected in a series circuit, the failure of one lightbulb would not cause a whole circuit to fail. Some eminent scientists predicted that such a circuit could never be feasible, but their findings were based on systems of lamps with low resistance—the only successful type of electric light at the time. Edison, however, determined that a bulb with high resistance would serve his purpose, and he began searching for a suitable one.

He had the assistance of 26-year-old Francis Upton, a graduate of Princeton University with an M.A. in science. Upton, who joined the laboratory force in December 1878, provided the mathematical and theoretical expertise that Edison himself lacked. (Edison later revealed, “At the time I experimented on the incandescent lamp I did not understand Ohm’s law.” On another occasion he said, “I do not depend on figures at all. I try an experiment and reason out the result, somehow, by methods which I could not.
By the summer of 1879 Edison and Upton had made enough progress on a generator—which, by reverse action, could be employed as a motor—that Edison, beset by failed incandescent lamp experiments, considered offering a system of electric distribution for power, not light. By October Edison and his staff had achieved encouraging results with a complex, regulator-controlled vacuum bulb with a platinum filament, but the cost of the platinum would have made the incandescent light impractical. While experimenting with an insulator for the platinum wire, they discovered that, in the greatly improved vacuum they were now obtaining through advances made in the vacuum pump, carbon could be maintained for some time without elaborate regulatory apparatus. Advancing on the work of Joseph Wilson Swan, an English physicist, Edison found that a carbon filament provided a good light with the concomitant high resistance required for subdivision. Steady progress ensued from the first breakthrough in mid-October until the initial demonstration for the backers of the Edison Electric Light Company on December 3.

It was, nevertheless, not until the summer of 1880 that Edison determined that carbonized bamboo fibre made a satisfactory material for the filament, although the world’s first operative lighting system had been installed on the steamship Columbia in April. The first commercial land-based “isolated” (single-building) incandescent system was placed in the New York printing firm of Hinds and Ketcham in January 1881. In the fall a temporary, demonstration central power system was installed at the Holborn Viaduct in London, in conjunction with an exhibition at the Crystal Palace. Edison himself supervised the laying of the mains and installation of the world’s first permanent, commercial central power system in lower Manhattan, which became operative in September 1882. Although the early systems were plagued by problems and many years passed before incandescent lighting powered by electricity from central stations made significant inroads into gas lighting, isolated lighting plants for such enterprises as hotels, theatres, and stores flourished—as did Edison’s reputation as the world’s greatest inventor.

One of the accidental discoveries made in the Menlo Park laboratory during the development of the incandescent light anticipated the British physicist J.J. Thomson’s discovery of the electron 15 years later. In 1881–82 William J. Hammer, a young engineer in charge of testing the light globes, noted a blue glow around the positive pole in a vacuum bulb and a blackening of the wire and the bulb at the negative pole. This phenomenon was first called “Hammer’s phantom shadow,” but when Edison patented the bulb in 1883 it became known as the “Edison effect.” Scientists later determined that this effect was explained by the thermionic emission of electrons from the hot to the cold electrode, and it became the basis of the electron tube and laid the foundation for the electronics industry.

Edison had moved his operations from Menlo Park to New York City when work commenced on the Manhattan power system. Increasingly, the Menlo Park property was used only as a summer home. In August 1884 Edison’s wife, Mary, suffering from deteriorating health and subject to periods of mental derangement, died there of “congestion of the brain,” apparently a tumour or hemorrhage. Her death and the move from Menlo Park roughly mark the halfway point of Edison’s life.

The Edison laboratory

A widower with three young children, Edison, on February 24, 1886, married 20-year-old Mina Miller, the daughter of a prosperous Ohio manufacturer. He purchased a hilltop estate in West Orange, New Jersey, for his new bride and constructed nearby a grand, new laboratory, which he intended to be the world’s first true research facility. There, he produced the commercial phonograph, founded the motion-picture industry, and developed the alkaline storage battery. Nevertheless, Edison was past the peak of his productive period. A poor manager and organizer, he worked best in intimate, relatively unstructured surroundings with a handful of close associates and assistants; the West Orange laboratory was too sprawling and diversified for his talents. Furthermore, as a significant portion of the inventor’s time was taken up by his new role of industrialist, which came with the commercialization of incandescent lighting and the phonograph, electrical developments were passing into the domain of university-trained mathematicians and scientists. Above all, for more than a decade Edison’s energy was focused on a magnetic ore-mining venture that proved the unquestioned disaster of his career.

The first major endeavour at the new laboratory was the commercialization of the phonograph, a venture launched in 1887 after Alexander Graham Bell, his cousin Chichester, and Charles Tainter had developed the graphophone—an improved version of Edison’s original device—which used waxed cardboard instead of tinfoil. Two years later, Edison announced that he had “perfected” the phonograph, although this was far from true. In fact, it was not until the late 1890s, after Edison had established production and recording facilities adjacent to the laboratory, that all the mechanical problems were overcome and the phonograph became a profitable proposition.

In the meantime, Edison conceived the idea of popularizing the phonograph by linking to it in synchronization a zoetrope, a device that gave the illusion of motion to photographs shot in sequence. He assigned the project to William K.L. math, an employee interested in photography, in 1888. After studying the work of various European photographers who also were trying to record motion, Edison and math succeeded in constructing a working camera and a viewing instrument, which were called, respectively, the Kinetograph and the Kinetoscope. Synchronizing sound and motion proved of such insuperable difficulty, however, that the concept of linking the two was abandoned, and the silent movie was born. Edison constructed at the laboratory the world’s first motion-picture stage, nicknamed the “Black Maria,” in 1893, and the following year Kinetoscopes, which had peepholes that allowed one person at a time to view the moving pictures, were introduced with great success. Rival inventors soon developed screen-projection systems that hurt the Kinetoscope’s business, however, so Edison acquired a projector developed by Thomas Armat and introduced it as “Edison’s latest marvel, the Vitascope.”

Another derivative of the phonograph was the alkaline storage battery, which Edison began developing as a power source for the phonograph at a time when most homes still lacked electricity. Although it was 20 years before all the difficulties with the battery were solved, by 1909 Edison was a principal supplier of batteries for submarines and electric vehicles and had even formed a company for the manufacture of electric automobiles. In 1912 Henry Ford, one of Edison’s greatest admirers, asked him to design a battery for the self-starter, to be introduced on the Model T. Ford’s request led to a continuing relationship between these two Americans, and in October 1929 he staged a 50th-anniversary celebration of the incandescent light that turned into a universal apotheosis for Edison.

Most of Edison’s successes involved electricity or communication, but throughout the late 1880s and early 1890s the Edison Laboratory’s top priority was the magnetic ore-separator. Edison had first worked on the separator when he was searching for platinum for use in the experimental incandescent lamp. The device was supposed to cull platinum from iron-bearing sand. During the 1880s iron ore prices rose to unprecedented heights, so that it appeared that, if the separator could extract the iron from unusable low-grade ores, then abandoned mines might profitably be placed back in production. Edison purchased or acquired rights to 145 old mines in the east and established a large pilot plant at the Ogden mine, near Ogdensburg, New Jersey. He was never able to surmount the engineering problems or work the bugs out of the system, however, and when ore prices plummeted in the mid-1890s he gave up on the idea. By then he had liquidated all but a small part of his holdings in the General Electric Company, sometimes at very low prices, and had become more and more separated from the electric lighting field.

Failure could not discourage Edison’s passion for invention, however. Although none of his later projects were as successful as his earlier ones, he continued to work even in his 80s.

The thrust of Edison’s work may be seen in the clustering of his patents: 389 for electric light and power, 195 for the phonograph, 150 for the telegraph, 141 for storage batteries, and 34 for the telephone. His life and achievements epitomize the ideal of applied research. He always invented for necessity, with the object of devising something new that he could manufacture. The basic principles he discovered were derived from practical experiments, invariably by chance, thus reversing the orthodox concept of pure research leading to applied research.

Edison’s role as a machine shop operator and small manufacturer was crucial to his success as an inventor. Unlike other scientists and inventors of the time, who had limited means and lacked a support organization, Edison ran an inventive establishment. He was the antithesis of the lone inventive genius, although his deafness enforced on him an isolation conducive to conception. His lack of managerial ability was, in an odd way, also a stimulant. As his own boss, he plunged ahead on projects more prudent men would have shunned, then tended to dissipate the fruits of his inventiveness, so that he was both free and forced to develop new ideas. Few men have matched him in the positiveness of his thinking. Edison never questioned whether something might be done, only how.

Edison’s career, the fulfillment of the American dream of rags-to-riches through hard work and intelligence, made him a folk hero to his countrymen. In temperament he was an uninhibited egotist, at once a tyrant to his employees and their most entertaining companion, so that there was never a dull moment with him. He was charismatic and courted publicity, but he had difficulty socializing and neglected his family. His shafts at the expense of the “long-haired” fraternity of theorists sometimes led formally trained scientists to deprecate him as anti-intellectual; yet he employed as his aides, at various times, a number of eminent mathematical physicists, such as Nikola Tesla and A.E. Kennelly. The contradictory nature of his forceful personality, as well as such eccentricities as his ability to catnap anywhere, contributed to his legendary status. By the time he was in his middle 30s Edison was said to be the best-known American in the world. When he died he was venerated and mourned as the man who, more than any other, had laid the basis for the technological and social revolution of the modern electric world.


#21 Re: Dark Discussions at Cafe Infinity » crème de la crème » 2015-11-27 15:19:59

21. Steven Allan Spielberg (born December 18, 1946) is an American director, producer and screenwriter. Spielberg is considered as one of the founding pioneers of the New Hollywood era, as well as being viewed as one of the most popular and influential directors and producers in film history. In a career spanning more than four decades, Spielberg's films have covered many themes and genres. Spielberg's early science-fiction and adventure films were seen as archetypes of modern Hollywood blockbuster filmmaking. In later years, his films began addressing humanistic issues such as the Holocaust (in Schindler's List), the transatlantic slave trade (in Amistad), war (in Empire of the Sun, Saving Private Ryan, and War Horse), and terrorism (in Munich). He is one of the co-founders of DreamWorks Studios.

His other films include Close Encounters of the Third Kind, the Indiana Jones film series, and A.I. Artificial Intelligence. Spielberg won the Academy Award for Best Director for Schindler's List (1993) and Saving Private Ryan (1998). Three of Spielberg's films- Jaws (1975), E.T. the Extra-Terrestrial (1982), and Jurassic Park (1993)- achieved box office records, originated and came to epitomize the blockbuster film.

The unadjusted gross of all Spielberg-directed films exceeds $9 billion worldwide, making him the highest-grossing director in history. His personal net worth is estimated to be more than $3 billion.


#22 Re: Ganesh's Puzzles » Doc, Doc! » 2015-11-27 12:00:15

Hi bobbym,

The Answer #1038 (Masseter muscle) is perfect! Wonderful!

#1039. Name the medical term / phrase -  Historically cited as the pneumogastric nerve, is the tenth cranial nerve or CN X, and interfaces with parasympathetic control of the heart and digestive tract. They are paired; however, they are normally referred to in the singular. Upon leaving the medulla oblongata between the pyramid and the inferior cerebellar peduncle, it extends through the jugular foramen, then passes into the carotid sheath between the internal carotid artery and the internal jugular vein down to the neck, chest and abdomen, where it contributes to the innervation of the viscera. Besides giving some output to various organs, it comprises between 80% and 90% of afferent nerves mostly conveying sensory information about the state of the body's organs to the central nervous system.

#23 Re: Ganesh's Puzzles » English language puzzles » 2015-11-27 11:47:13

Hi bobbym,

Both the Answers, #2185 and #2186, are both correct! Marvelous!

#2187. What does the adjective asynchronous mean?

#2188. What does the preposition astride mean?

#24 Re: Ganesh's Puzzles » Series and Progressions » 2015-11-27 11:19:43

Hi bobbym,

SP #136. Find the sum:


#25 Re: Ganesh's Puzzles » Doc, Doc! » 2015-11-26 22:13:03

Hi bobbym,

Excellent, bobbym!

#1038. Name the medical term / phrase- In human anatomy, it is one of the muscles of mastication. In the animal kingdom, it is particularly powerful in herbivores to facilitate chewing of plant matter. The most obvious muscle of mastication is this, since it is the most superficial and one of the strongest. It  is a thick, somewhat quadrilateral muscle, consisting of two heads, superficial and deep. The fibers of the two heads are continuous at their insertion.

Board footer

Powered by FluxBB