Well know dates of indian history (B.C)

B.C
300-1500 indus valley civilisation, mohenjodaro and harappa.
599  Birth of mahavira at kundagram in Bhihar . Propounded Jainism.mahavira's nirvana(527B.C.)
567 Birth of gautama buddha's Nirvana (487 B.C.)
327-326 AAlexander's invasion of india.He only succeeded in conquering the old Persian satraps (Viceroys ) of Gandhara and tha indus valley. the heart of the country was left untouched. he could not make this conquest permanect and effective. it opened a land route between india and Europe.
322 Chandragupta Maurya's accession to the throne of magadh.
305 Seleucus Nicatior invaded india, but was defeated by Chandra Gupta Maurya.
273-232 Ashok's reign.
261 Conquest of kalinga.

LIGHT BULB HISTORY-INVENTION OF THE LIGHT BULB

AT A GLANCE: The modern world is an electrified world. The light bulb, in particular, profoundly changed human existence by illuminating the night and making it hospitable to a wide range of human activity. The electric light, one of the everyday conveniences that most affects our lives, was invented in 1879 by Thomas Alva Edison. He was neither the first nor the only person trying to invent an incandescent light bulb. THE STORY RELATED INFO BOOKS VIDEOS WEB SITES QUOTATIONS HOW IT WORKS DID YOU KNOW? Invention: electric light bulb in 1879 Definition: noun / electric light bulb / incandescent lamp Function: An electric lamp in which a filament is heated to incandescence by an electric current. Today's incandescent light bulbs use filaments made of tungsten rather than carbon of the 1880's. Patent: 223,898 (US) issued January 27, 1880 Inventor: Thomas Alva Edison Criteria: First practical. Modern prototype. Entrepreneur. Birth: February 11, 1847 in Milan, Ohio Death: October 18, 1931 in West Orange, New Jersey Nationality: American Milestones: 1850 Joseph W. Swan began working on a light bulb using carbonized paper filaments 1860 Swan obtained a UK patent covering a partial vacuum, carbon filament incandescent lamp 1877 Edward Weston forms Weston Dynamo Machine Company, in Newark, New Jersey. 1878 Thomas Edison founded the Edison Electric Light Company 1878 Hiram Maxim founded the United States Electric Lighting Company 1878 205,144 William Sawyer and Albon Man 6/18 for Improvements in Electric Lamps 1878 Swan receives a UK patent for an improved incandescent lamp in a vacuum tube 1879 Swan began installing light bulbs in homes and landmarks in England. 1880 223,898 Thomas Edison 1/27 for Electric Lamp and Manufacturing Process 1880 230,309 Hiram Maxim 7/20 for Process of Manufacturing Carbon Conductors 1880 230,310 Hiram Maxim 7/20 for Electrical Lamp 1880 230,953 Hiram Maxim 7/20 for Electrical Lamp 1880 233,445 Joseph Swan 10/19 for Electric Lamp 1880 234,345 Joseph Swan 11/9 for Electric Lamp 1880 Weston Dynamo Machine Company renamed Weston Electric Lighting Company 1880 Elihu Thomson and Edwin Houston form American Electric Company 1880 Charles F. Brush forms the Brush Electric Company 1881 Joseph W. Swan founded the Swan Electric Light Company 1881 237,198 Hiram Maxim 2/1 for Electrical Lamp assigned to U.S. Electric Lighting Company 1881 238,868 Thomas Edison 3/15 for Manufacture of Carbons for Incandescent Lamps 1881 247,097 Joseph Nichols and Lewis Latimer 9/13 for Electric Lamp 1881 251, 540 Thomas Edison 12/27 for Bamboo Carbons Filament for Incandescent Lamps 1882 252,386 Lewis Latimer 1/17 for Process of Manufacturing Carbons assigned to U.S. E. L. Co. 1882 Edison's UK operation merged with Swan to form the Edison & Swan United Co. or "Edi-swan" 1882 Joesph Swan sold his United States patent rights to the Brush Electric Company 1883 American Electric Company renamed Thomson-Houston Electric Company 1884 Sawyer & Man Electric Co formed by Albon Man a year after William Edward Sawyer death 1886 George Westinghouse formed the Westinghouse Electric Company 1886 The National Carbon Co. was founded by the then Brush Electric Co. executive W. H. Lawrence 1888 United States Electric Lighting Co. was purchased by Westinghouse Electric Company 1886 Sawyer & Man Electric Co. was purchased by Thomson-Houston Electric Company 1889 Brush Electric Company merged into the Thomson-Houston Electric Company 1889 Edison Electric Light Company consolidated and renamed Edison General Electric Company. 1890 Edison, Thomson-Houston, and Westinghouse, the "Big 3" of the American lighting industry. 1892 Edison Electric Light Co. and Thomson-Houston Electric Co. created General Electric Co. light bulb, electric lamp, incandescent lamp, electric globe, Thomas Edison, Joseph Swan, Hiram Maxim, Humphrey Davy, James Joule, George Westinghouse, Charles Brush, William Coolidge, invention, history, inventor of, history of, who invented, invention of, fascinating facts.

The Story: By the time of Edison's 1879 lamp invention, gas lighting was a mature, well-established industry. The gas infrastructure was in place, franchises had been granted, and manufacturing facilities for both gas and equipment were in profitable operation. Perhaps as important, people had grown accustomed to the idea of lighting with gas. Incandescent lamps make light by using electricity to heat a thin strip of material (called a filament) until it gets hot enough to glow. Many inventors had tried to perfect incandescent lamps to "sub-divide" electric light or make it smaller and weaker than it was in the existing electric arc lamps, which were too bright to be used for small spaces such as the rooms of a house.Edison was neither the first nor the only person trying to invent an incandescent electric lamp. Many inventors had tried and failed some were discouraged and went on to invent other devices. Among those inventors who made a step forward in understanding the eclectic light were Sir Humphrey Davy, Warren De la Rue, James Bowman Lindsay, James Prescott Joule, Frederick de Moleyns and Heinrich Göbel. Between the years 1878 and 1892 the electric light industry was growing in terms of installed lights but shrinking in terms of company competition as both Thomas Edison and George Westinghouse determined to control the industry and its advancement. They even formed the Board of Patent Control, a joint arrangement between General Electric and the Westinghouse Company to defend the patents of the two companies in litigation. This proved to be a wise decision as over 600 lawsuits for patent infringement were filed. The easiest way to understand those turbulent times in the early lighting industry is to follow the company's involved. Of the hundreds of companies in the business, we only cover the major players. We show the flow of inventor's patents and inventor's companies and how the industry ended up monopolized by GE and Westinghouse. Company names listed in GREEN ultimately became part of General Electric. Company names listed in RED ultimately became part of Westinghouse. American Electric Company. In the late 1870's high school teachers Elihu Thomson and Edwin Houston began experimenting with and patenting improvements on existing arc lamp and dynamo designs. In 1880 after being approached by a group of businessmen from New Britain CT, They all agreed to the formation of a company that would engage in the commercial manufacture of lighting systems (both arc and incandescent) based on their own patents. This was the American Electric Company which existed until 1883 when it was reorganized and was renamed the Thomson-Houston Electric Company. Brush Electric Company In 1880, Charles F. Brush forms the Brush Electric Company. That same year he installs the first complete eclectic arc-lighting system in Wabash, Indiana. Wabash was the first American city to be lit solely by electricity and to own its own municipal power plant (that small dynamo driven by a threshing machine engine). The installation in Cleveland the year before had been a demonstration, but Cleveland would soon begin lighting its streets with arc lamps as well. In 1876 Charles F. Brush invented a new type of simple, reliable, self-regulating arc lamp, as well as a new dynamo designed to power it. Earlier attempts at self regulation had often depended on complex clockwork mechanisms that, among other things, could not automatically re-strike an arc if there were an interruption in power. The simpler Brush design for a lamp/dynamo system made central station lighting a possibility for the first time.  Joseph Swan sold his United States patent rights to the Brush Electric Company in June 1882. In 1889, Brush Electric Company merged into the Thomson-Houston Electric Company. Edison Electric Light Company In the period from 1878 to 1880 Edison and his associates worked on at least three thousand different theories to develop an efficient incandescent lamp. Edison’s lamp would consist of a filament housed in a glass vacuum bulb. He had his own glass blowing shed where the fragile bulbs were carefully crafted for his experiments. Edison was trying to come up with a high resistance system that would require far less electrical power than was used for the arc lamps. This could eventually mean small electric lights suitable for home use. By January 1879, at his laboratory in Menlo Park, New Jersey, Edison had built his first high resistance, incandescent electric light. It worked by passing electricity through a thin platinum filament in the glass vacuum bulb, which delayed the filament from melting. Still, the lamp only burned for a few short hours. In order to improve the bulb, Edison needed all the persistence he had learned years before in his basement laboratory. He tested thousands and thousands of other materials to use for the filament. He even thought about using tungsten, which is the metal used for light bulb filaments now, but he couldn’t work with it given the tools available at that time. He tested the carbonized filaments of every plant imaginable, including bay wood, boxwood, hickory, cedar, flax, and bamboo. He even contacted biologists who sent him plant fibers from places in the tropics. Edison acknowledged that the work was tedious and very demanding, especially on his workers helping with the experiments. He always recognized the importance of hard work and determination. "Before I got through," he recalled, "I tested no fewer than 6,000 vegetable growths, and ransacked the world for the most suitable filament material." Edison decided to try a carbonized cotton thread filament. When voltage was applied to the completed bulb, it began to radiate a soft orange glow. Just about fifteen hours later, the filament finally burned out. Further experimentation produced filaments that could burn longer and longer with each test. By the end of 1880, he had produced a 16-watt bulb that could last for 1500 hours and he began to market his new invention. In Britain, Swan took Edison to court for patent infringement. Edison lost and as part of the settlement, Edison was forced to take Swan in as a partner in his British electric works. The company was called the Edison and Swan United Electric Company (later known as Ediswan which was then incorporated into Thorn Lighting Ltd). Eventually, Edison acquired all of Swan's interest in the company. Swan sold his United States patent rights to the Brush Electric Company in June 1882. In 1889 the Edison Electric Light Company merged with several other Edison companies to become the Edison General Electric Company. When the Edison General Electric Company merged with Thomson-Houston in 1892, a bitter struggle developed, Edison's name was dropped, and Edison himself had no more involvement with the newly formed General Eclectic Company beyond defending his patents. In 1903 Willis Whitnew invented a filament that would not blacken the inside of a light bulb. It was a metal-coated carbon filament. In 1906, the General Electric Company was the first to patent a method of making tungsten filaments for use in incandescent light bulbs. The filaments were costly, but by 1910 William David Coolidge had invented an improved method of making tungsten filaments. The tungsten filament outlasted all other types of filaments and Coolidge made the costs practical. Edison & Swan United Electric Company In Britain, Joseph Swan took Edison to court for patent infringement. Edison lost and as part of the settlement, Edison was forced to take Swan in as a partner in his British electric works. The company was called the Edison and Swan United Electric Company (later known as Ediswan). Eventually, Edison acquired all of Swan's interest in the company. General Electric Company In 1892, a merger of Edison General Electric Company and Thomson-Houston Electric Company created General Electric Company. General Electric, GE is the only company listed in the Dow Jones Industrial Index today that was also included in the original index in 1896. Sawyer & Man Electric Company William Sawyer and Albon Man are issued Patent No, 205,144 on June 18, 1878 for Improvements in Electric Lamps. In 1884, Albon Man formed the Sawyer & Man Electric Co for the purpose of protecting the  Sawyer-Man electric lamp patent. William Sawyer had died the previous year. In 1886, the Thomson-Houston Electric Company purchased the Sawyer & Man Electric Company and began making incandescent lamps under the Sawyer-Man patents. Swan Electric Light Company Joseph Wilson Swan (1828-1914) was a physicist and chemist born in Sunderland, England. Swan was the first to construct an electric light bulb, but he had trouble maintaining a vacuum in his bulb. In 1850 he began working on a light bulb using carbonized paper filaments in an evacuated glass bulb. By 1860 he was able to demonstrate a working device, and obtained a UK patent covering a partial vacuum, carbon filament incandescent lamp. However, the lack of good vacuum and an adequate electric source resulted in a short lifetime for the bulb and an inefficient light. Fifteen years later, in 1875, Swan returned to consider the problem of the light bulb and, with the aid of a better vacuum and a carbonized thread as a filament. The most significant feature of Swan's lamp was that there was little residual oxygen in the vacuum tube to ignite the filament, thus allowing the filament to glow almost white-hot without catching fire. Swan received a British patent for his device in 1878 . Swan had reported success to the Newcastle Chemical Society and at a lecture in Newcastle in February 1879 he demonstrated a working lamp. Starting that year he began installing light bulbs in homes and landmarks in England. In 1880, Swan gave the world's first large-scale public exhibition of electric lamps at Newcastle upon Tyne England. In 1881 he had started his own company, The Swan Electric Light Company, and started commercial production. Swan took Edison to court in Britain for patent infringement. Edison lost and as part of the settlement, Edison was forced to take Swan in as a partner in his British electric works. The company was called the Edison and Swan United Electric Company (later known as Ediswan). Eventually, Edison acquired all of Swan's interest in the company. Also in 1882 Joseph Swan sold his United States patent rights to the Brush Electric Company, a successful "arc" street light manufacture. Thomson-Houston Electric Company In the late 1870's high school teachers Elihu Thomson, a teacher of physics and chemistry, and Edwin Houston, a science teacher, began experimenting with and patenting improvements on existing arc lamp and dynamo designs. In 1880 after being approached by a group of businessmen from New Britain CT, Thomson & Houston agreed to the formation of a company that would engage in the commercial manufacture of lighting systems (both arc and incandescent) based on their own patents. This was the American Electric Company which existed until 1883 when it was reorganized and was renamed the Thomson-Houston Electric Company. . The company became quite successful and diversified into other electrical markets. In 1886 they purchased the Sawyer & Man Electric Co. and began making incandescent lamps under the Sawyer-Man patents. In 1889 in an attempt to avoid patent disputes over a double-carbon arc lamp design, Thomson-Houston negotiated the purchase of a controlling interest in the Brush company. The Swan Incandescent Light Company was part of the Brush plant so it was included in the takeover. In 1892 Thomson-Houston merged with the Edison companies to form the giant General Electric Company. United States Electric Lighting Company Founded in 1878 by the prolific inventor Hiram Maxim, the United States Electric Lighting soon established itself as Thomas Edison's chief rival in the field of incandescent lighting. The company made some of the earliest installations of this new technology using Maxim's patent on a carbon-filament lamp, which was similar to that invented by Edison in 1879. When Maxim left USEL in 1881 to pursue other lines of invention, the company purchased the Weston Electric Lighting Company in Newark, NJ, and the services of its founder Edward Weston. The inventor of a successful "arc" lighting system, Weston, as works manager and chief designer of USEL, developed a comprehensive arc and incandescent system which the USEL began to market in 1882. In January 1882, Lewis Latimer, an employee of USEL, received a patent for the "Process of Manufacturing Carbons," an improved method for the production of light bulb filaments which yielded longer lasting bulbs than Edison's technique. In 1888, United States Electric Lighting Co. was purchased by Westinghouse Electric Company. Westinghouse Electric Company In 1886, George Westinghouse formed the Westinghouse Electric Company. The main function of the Electric & Manufacturing Company was to develop and produce "apparatus for the generation, transmission and application of alternating current electricity." The company also produced electric railway motors, producing approximately 75,000 by 1905. Weston Electric Lighting Company Founded in New Jersey by Edward Weston in 1880, the company's innovations included the Weston standard cell, the first accurate portable voltmeters and ammeters, the first portable light meter, and many other electrical developments. In 1881, the United States Electric Lighting Company purchased the Weston Electric Lighting Company, and the services of its founder Edward Weston. The inventor of a successful "arc" lighting system, Weston, as works manager and chief designer of USEL, developed a comprehensive arc and incandescent system which the USEL began to market in 1882. Woodward and Evans Light On July 24, 1874 a Canadian patent was filed for the Woodward and Evans Light by a Toronto medical electrician named Henry Woodward and a colleague Mathew Evans, who was described in the patent as a "Gentleman" but in reality a hotel keeper. They built their lamp with a shaped rod of carbon held between electrodes in a glass globe filled with nitrogen. Woodward and Evans found it impossible to raise financial support for the development of their invention and in 1875 Woodward sold a share of their Canadian patent to Thomas Edison. The Edison Vision The economic effect of electric lighting went far beyond increasing the workday. Profits generated by the electric lamp, in effect, paid for a network of generators and wires. This infrastructure then became available for a whole new class of inventions: appliances and equipment that by the 1930s had transformed the home and the workplace. Edison didn't just invent a light bulb, either. He put together what he knew about electricity with what he knew about gas lights and invented a whole system of electric lighting. This meant light bulbs, electricity generators, wires to get the electricity from the power station to the homes, fixtures (lamps, sockets, switches) for the light bulbs, and more. It was like a big jigsaw puzzle--and Edison made up the pieces as well as fitted them together. He did it his way.

TO LEARN MORE RELATED INFORMATION: Thomas Alva Edison Biography    from The Great Idea Finder Joseph Swan Biography    from The Great Idea Finder Louis Latimer Biography   from The Great Idea Finder George Westinghouse Biography   from The Great Idea Finder Evoloution of Electricity    from The Great Idea Finder History of Household Items    from The Great Idea Finder Energy History    from The Great Idea Finder ON THE BOOKSHELF: 100 Inventions That Shaped World History by Bill Yenne, Morton, Dr. Grosser (Editor) / Paperback - 112 pages (1983) / Bluewood Books  This book contains inventions from all around the world from microchips to fire. This is a really good book if you are going to do research on inventions. Panati’s Extraordinary Origins of Everyday Things by Charles Panati / Paperback - 480 pages Reissue edition (September 1989) / HarperCollins Discover the fascinating stories behind the origins of over 500 everyday items, expressions and customs. Edison: A Life of Invention by Paul Israel / Hardcover: 480 pages / John Wiley & Sons; (October 1998) The well-known inventions--the incandescent lightbulb, the phonograph, the kinetoscope for motion pictures, the carbon transmitter for telephones--are all here in detail, and so are the lesser-known ones as well as some Edisonian projects that did not succeed. Edison : A Biography (Limited Availability) by Matthew Josephson / Paperback: 528 pages / Wiley; Reprint edition (February 11, 1992) Regarded as the classic standard biography on Thomas Edison. It is the only biography written in the last 40 years to be recommended by the official voice of the caretakers of the Edison Laboratory National Monument in New Jersey which houses all of Edison's original records, sketches, notes, correspondence and memoranda. At Work With Thomas Edison by Blaine McCormick / Paperback: 272 pages / Entrepreneur Press; 1 edition (December 1, 2001) In addition to patenting over 1,000 inventions, Edison was a capable businessman who recognized that innovation is a business, emphasizing the importance of creating a company that produces more than just one good idea. Edison never invented simply to create a new thing, but rather focused on crafting something that would have a practical use. Brandy, Balloons, & Lamps: Ami Argand, 1750-1803 (Limited availability.) by John J. Wolfe / Hardcover - 240 pages (June 1999) / Southern Illinois Univ Pr (Txt); Little has been written about Ami Argand and the development of the Argand lamp, a two-air draft burner for oil lamps, especially as his discovery is generally recognized as the first scientific advancement in lighting. The Lightbulb  (Limited availability.) by Joseph Wallace / School & Library Binding - 80 pages (September 1999) / Atheneum When Thomas Alva Edison was a boy, he couldn't just flick a switch to turn on the light if he wanted to finish reading a book after the sun had set. Then, in 1879, he invented the ightbulb, and houses, shops, factories, schools, streets, ballparks -- every place you could think of, indoors and out -- could at last be easily illuminated after dark. Edison: Inventing the Century  (Limited availability.) Neil Baldwin / Paperback / Published 1996 Using unprecedented access to Edison family papers and years of research at the Edison corporate archives, Neil Baldwin offers a revealing portrait of one of America's seminal inventors. ON THE SCREEN: Thomas Edison DVD / 1 Volume Set / 50 Minutes / Bipgraphy Channel / Less than $25.00 / Also VHS Life in the modern world would be unthinkable without his inventions. More than any other individual, he paved the way for the future. Thomas Alva Edison has rightly earned a place among the most important men in history. ON THE WEB: Edison's Light Bulb From the The Franklin Institute Science Museum. (URL: sln.fi.edu/qa98/attic12/attic12.html) GE Follows Thomas Edison's Lead and Shines a Light on Innovation What would Thomas Edison think of incandescent lights that last 750 hours or filter out harsh colors of the spectrum to provide a purer, cleaner light? Little did he know his light bulb that lasted only 40 hours would lead to products like the Reveal® bulb, which has sold more than 170 million since 2001. (URL: www.ge.com) United States Electric Lighting - Weston Electric Lighting Company Founded in 1878 by the prolific inventor Hiram Maxim, the USEL soon established itself as Thomas Edison's chief rival in the field of incandescent lighting. The company purchased the Weston Electric Lighting Company in Newark, NJ, and the services of its founder Edward Weston. (URL: www.ieee.org/organizations/history_center/milestones_photos/central_station.html) Incandescent Lamp Patents Presented by Kilokat's antique light bulb site. A bulb collectors dream come true. (URL: bulbcollector.com/gateway/Patent_Archive/Incandescent_Lamp_Patents) Lighting a Revolution This web site accompanies an exhibition at the National Museum of American History exploring the process of invention. The story is told in two parallel sections comparing Thomas Edison's light bulb invention with several electric lighting inventions of a century later. (URL: americanhistory.si.edu/lighting/index.htm) Thomson-Houston Elihu Thomson joined with Edwin Houston, a fellow teacher, experimenting in things such as arc-lighting and centrifugal force. They made several inventions and improvements in both fields. (URL: www.swampscotthistory.org/docs/thomson.html) Electric Museum Charles F. Brush invented a new type of simple, reliable, self-regulating arc lamp, as well as a new dynamo designed to power it. Site maintained by Charles Brush the great grandson of the founder of Brush Electric Company. (URL: www.electricmuseum.com) Weston Electric Lighting Company Founded in New Jersey by Edward Weston in 1888, the company's innovations included the Weston standard cell, the first accurate portable voltmeters and ammeters, the first portable lightmeter, and many other electrical developments. (URL: weston.ftldesign.com/) Charles Brush Charles F. Brush designed and developed an electric arc lighting system that was adopted throughout the United States and abroad during the 1880's. His inventive genius ranked with an elite group of electric pioneers including Thomas A. Edison. (URL: www.lafavre.us/brush/brushbio.htm) Edison Invents! Allm about Edison and his inventions. Thomas Alva Edison changed our world! His genius gave us electric lights in our home. From the Lemelson Center at the Smithsonian. (URL: invention.smithsonian.org/centerpieces/edison/default.asp) Edisonian This site presented by the Edisonian Museum offers photographs and descriptions of many of Thomas Edison's inventions. (URL: www.edisonian.com/) National Inventors Hall of Fame Located at Inventure Place, the online home of creative minds.Thomas Edison was inducted in 1973 for his invention of the Electric Lamp Patent Number 223,898. (URL: www.invent.org/hall_of_fame/50.html) Invention Dimension - Inventor of the Week Celebrates inventor/innovator role models through outreach activities and annual awards to inspire a new generation of American scientists, engineers, and entrepreneurs. Featured Thomas Alva Edison for his invention of the Electric Light Bulb. (URL: web.mit.edu/invent/iow/edison.html) Consequences of Edison's Lamp Over the course of the next half century two especially significant social effects became clear. We gained control over light in homes and offices, independent of the time of day. And the electric light brought networks of wires into homes and offices, making it relatively easy to add appliances and other machines. From the Lighting Revolution at the Smithsonian. (URL: americanhistory.si.edu/lighting/19thcent/consq19.htm) Thomas A. Edison Papers Rutgers University has a section of their site dedicated to Edison. The goal of the project was to organize and publish a select edition of the estimated 5 million pages of Thomas Alva Edison's technical, business, and personal papers. (URL: edison.rutgers.edu/) The Westinghouse Electric & Manufacturing Company The main function of the Electric & Manufacturing Company was to develop and produce "apparatus for the generation, transmission and application of alternating current electricity." (URL: memory.loc.gov/ammem/papr/west/westelec.html) Guinness Book of World Records The oldest known working lightbulb was first installed at the fire department hose cart house in 1901. Then moved to fire station at First and McLeod, then to its present site in 1976 at the fire station, 4550 East Ave., Livermore, California (URL: www.centennialbulb.org/facts.htm) Early Incandescent Lamps The history of the electric incandescent lamp can be considered to have begun with the invention of the voltaic pile by Alessandro Volta in 1800. Although the earlier history needs to be revealed in detail, this site concentrates mainly on lamp development between the years 1880-1925. (URL: home.frognet.net/~ejcov/index40.html) WORDS OF WISDOM: "The electric light has caused me the greatest amount of study and has required the most elaborate experiments. I was never myself discouraged, or inclined to be hopeless of success. I cannot say the same for all my associates." - Thomas Alva Edison "Genius is one percent inspiration and ninety-nine percent perspiration." - Thomas Alva Edison HOW IT WORKS: The incandescent light bulb (archaically known as the electric lamp) uses a glowing wire filament heated to white-hot by electrical resistance, to generate light (a process known as thermal radiation or incandescence). The bulb is the glass enclosure which keeps the filament in a vacuum or low-pressure noble gas, or a halogen gas in the case of quartz-halogen lamps in order to prevent oxidation of the filament at high temperatures. Because of its poor efficiency and yellowish color, incandescent light bulb are gradually being replaced in many applications by fluorescent lights, high-intensity discharge lamps, LEDs, and other devices. You can view an incandescent light bulb illustration at the Merriam-Webster Web site. The incandescent light bulb consists of six componets;: 1 bulb containing gas, 2 filament, 3 connecting and supporting wires, 4 exhaust tube, 5 screw base, 6 base contact. DID YOU KNOW? General Electric, GE is the only company listed in the Dow Jones Industrial Index today that was also included in the original index in 1896.

HOW MAGNET IS MADE

A magnet is a material that can exert a noticeable force on other materials without actually contacting them. This force is known as a magnetic force and may either attract or repel. While all known materials exert some sort of magnetic force, it is so small in most materials that it is not readily noticeable. With other materials, the magnetic force is much larger, and these are referred to as magnets. The Earth itself is a huge magnet.

Some magnets, known as permanent magnets, exert a force on objects without any outside influence. The iron ore magnetite, also known as lodestone, is a natural permanent magnet. Other permanent magnets can be made by subjecting certain materials to a magnetic force. When the force is removed, these materials retain their own magnetic properties. Although the magnetic properties may change over time or at elevated temperatures, these materials are generally considered to be permanently magnetized, hence the name.

Other magnets are known as electromagnets. They are made by surrounding certain materials with a coil of wire. When an electric current is passed through the coil, these materials exert a magnetic force. When the current is shut off, the magnetic force of these materials drops to nearly zero. Electromagnet materials retain little, if any, magnetic properties without a flow of electric current in the coil.

All magnets have two points where the magnetic force is greatest. These two points are known as the poles. For a rectangular or cylindrical bar magnet, these poles would be at opposite ends. One pole is called the north-seeking pole, or north pole, and the other pole is called the south-seeking, or south pole. This terminology reflects one of the earliest uses of magnetic materials such as lodestone. When suspended from a string, the north pole of these first crude compasses would always "seek" or point towards the north. This aided sailors in judging the direction to steer to reach distant lands and return home.

In our present technology, magnet applications include compasses, electric motors, microwave ovens, coin-operated vending machines, light meters for photography, automobile horns, televisions, loudspeakers, and tape recorders. A simple refrigerator note holder and a complex medical magnetic resonance imaging device both utilize magnets.

History

Naturally occurring magnetic lodestone was studied and used by the Greeks as early as 500 B.C. Other civilizations may have known of it earlier than that. The word magnet is derived from the Greek name magnetis lithos, the stone of Magnesia, referring to the region on the Aegean coast in present-day Turkey where these magnetic stones were found.

The first use of a lodestone as a compass is generally believed to have occurred in Europe in about A.D. 1100 to A.D. 1200. The term lodestone comes from the Anglo-Saxon meaning "leading stone," or literally, "the stone that leads." The Icelandic word is leider-stein, and was used in writings of that period in reference to the navigation of ships.

In 1600, English scientist William Gilbert confirmed earlier observations regarding magnetic poles and concluded that the Earth was a magnet. In 1820, the Dutch scientist Hans Christian Oersted discovered the relationship between electricity and magnetism, and French physicist Andre Ampere further expanded upon this discovery in 1821.

In the early 1900s, scientists began studying magnetic materials other than those based on iron and steel. By the 1930s, researchers had produced the first powerful Alnico alloy permanent magnets. Even more powerful ceramic magnets using rare earth elements were successfully formulated in the 1970s with further advances in this area in the 1980s.

Today, magnetic materials can be made to meet many different performance requirements depending on the final application.

Raw Materials

When making magnets, the raw materials are often more important than the manufacturing process. The materials used in permanent magnets (sometimes known as hard materials, reflecting the early use of alloy steels for these magnets) are different than the materials used in electromagnets (some-times known as soft materials, reflecting the use of soft, malleable iron in this application).

Permanent Magnet Materials

Permanent magnet lodestones contain magnetite, a hard, crystalline iron ferrite mineral that derives its magnetism from the effect the earth's magnetic field has on it. Various steel alloys can also be magnetized. The first big step in developing more effective permanent magnet materials came in the 1930s with the development of Alnico alloy magnets. These magnets take their name from the chemical symbols for the aluminum-nickel-cobalt elements used to make the alloy. Once magnetized, Alnico magnets have between 5 and 17 times the magnetic force of magnetite.

Ceramic permanent magnets are made from finely powdered barium ferrite or strontium ferrite formed under heat and pressure. Their magnetic strength is enhanced by aligning the powder particles with a strong magnetic field during forming. Ceramic magnets are comparable to Alnico magnets in terms of magnetic force and have the advantage of being able to be pressed into various shapes without significant machining.

Flexible permanent magnets are made from powdered barium ferrite or strontium ferrite mixed in a binding material like rubber or a flexible plastic like polyvinyl chloride.

In the 1970s, researchers developed permanent magnets made from powdered samarium cobalt fused under heat. These magnets take advantage of the fact that the arrangement of the groups of atoms, called magnetic domains, in the hexagonal crystals of this material tend to be magnetically aligned. Because of this natural alignment, samarium-cobalt magnets can be made to produce magnetic forces 50 times stronger than magnetite. Headphones for small, personal stereo systems use samarium-cobalt permanent magnets. Samarium-cobalt magnets also have the advantage of being able to operate in higher temperatures than other permanent magnets without losing their magnetic strength.

Similar permanent magnets were made in the 1980s using powdered neodymium iron boron which produces magnetic forces almost 75 times stronger than magnetite. These are the most powerful permanent magnets commercially available today.

Electromagnet Materials

Pure iron and iron alloys are most commonly used in electromagnets. Silicon iron and specially treated iron-cobalt alloys are used in low-frequency power transformers.

A special iron oxide, called a gamma iron oxide, is often used in the manufacture of magnetic tapes for sound and data recording. Other materials for this application include

The above illustrations show a typical powdered metallurgy process used to produce powerful neodymium-iron-boron permanent magnets.

cobalt-modified iron oxides and chromium dioxide. The material is finely ground and coated on a thin polyester plastic film.

Other Magnetic Materials

Magnetic fluids can be made by encapsulating powdered barium ferrite particles in a single layer of molecules of a long-chain polymer plastic. The particles are then held in suspension in a liquid like water or oil. Because of the plastic encapsulation, the magnetic particles slide over each other with almost no friction. The particles are so small that normal thermal agitation in the liquid keeps the particles from settling. Magnetic fluids are used in several applications

as sealants, lubricants, or vibration damping materials.

The Manufacturing
Process

Just as the materials are different for different kinds of magnets, the manufacturing processes are also different. Many electromagnets are cast using standard metal casting techniques. Flexible permanent magnets are formed in a plastic extrusion process in which the materials are mixed, heated, and forced through a shaped opening under pressure.

Some magnets are formed using a modified powdered metallurgy process in which finely powdered metal is subjected to pressure, heat, and magnetic forces to form the final magnet. Here is a typical powdered metallurgy process used to produce powerful neodymium-iron-boron permanent magnets with cross-sectional areas of about 3-10 square inches (20-65 sq cm):

Preparing the powdered metal

• 1 The appropriate amounts of neodymium, iron, and boron are heated to melting in a vacuum. The vacuum prevents any chemical reaction between air and the melting materials that might contaminate the final metal alloy.
• 2 Once the metal has cooled and solidified, it is broken up and crushed into small pieces. The small pieces are then ground into a fine powder in a ball mill.

Pressing

• 3 The powdered metal is placed in a mold, called a die, that is the same length and width (or diameter, for round magnets) as the finished magnet. A magnetic force is applied to the powdered material to line up the powder particles. While the magnetic force is being applied, the powder is pressed from the top and bottom with hydraulic or mechanical rams to compress it to within about 0.125 inches (0.32 cm) of its final intended thickness. Typical pressures are about 10,000 psi to 15,000 psi (70 MPa to 100 MPa). Some shapes are made by placing the powdered material in a flexible, air-tight, evacuated container and pressing it into shape with liquid or gas pressure. This is known as isostatic compaction.

Heating

• 4 The compressed "slug" of powdered metal is removed from the die and placed in an oven. The process of heating compressed powdered metals to transform them into fused, solid metal pieces is called sintering. The process usually consists of three stages. In the first stage, the compressed material is heated at a low temperature to slowly drive off any moisture or other contaminants that may have become entrapped during the pressing process. In the second stage, the temperature is raised to about 70-90% of the melting point of the metal alloy and held there for a period of several hours or several days to allow the small particles to fuse together. Finally, the material is cooled down slowly in controlled, step-by-step temperature increments.

Annealing

• 5 The sintered material then undergoes a second controlled heating and cooling process known as annealing. This process removes any residual stresses within the material and strengthens it.

Finishing

• 6 The annealed material is very close to the finished shape and dimensions desired. This condition is known as "nearnet" shape. A final machining process removes any excess material and produces a smooth surface where needed. The material is then given a protective coating to seal the surfaces.

Magnetizing

• 7 Up to this point, the material is just a piece of compressed and fused metal. Even though it was subjected to a magnetic force during pressing, that force didn't magnetize the material, it simply lined up the loose powder particles. To turn it into a magnet, the piece is placed between the poles of a very powerful electromagnet and oriented in the desired direction of magnetization. The electromagnet is then energized for a period of time. The magnetic force aligns the groups of atoms, or magnetic domains, within the material to make the piece into a strong permanent magnet.

Quality Control

Each step of the manufacturing process is monitored and controlled. The sintering and annealing processes are especially critical to the final mechanical and magnetic properties of the magnet, and the variables of time and temperature must be closely controlled.

Hazardous Materials,
Byproducts, and
Recycling

Barium and the barium compounds used to make barium ferrite permanent magnets are poisonous and are considered toxic materials. Companies making barium ferrite magnets must take special precautions in the storage, handling, and waste disposal of the barium products.

Electromagnets can usually be recycled by salvaging the component iron cores and copper wiring in the coil. Partial recycling of permanent magnets may be achieved by removing them from obsolete equipment and using them again in similar new equipment. This is not always possible, however, and a more comprehensive approach to recycling permanent magnets needs to be developed.

The Future

Researchers continue to search for even more powerful magnets than those available today. One of the applications of more powerful permanent magnets would be the development of small, high-torque electric motors for battery-powered industrial robots and laptop computer disk drives. More powerful electromagnets could be used for the levitation and propulsion of high-speed trains using pulsed magnetic fields. Such trains, sometimes called maglev trains, would be supported and guided by a central, magnetic "rail." They would move without ever contacting the rail, thus eliminating mechanical friction and noise. Pulsed magnetic fields could also be used to launch satellites into space without relying on expensive and heavy booster rockets.

More powerful magnets could also be used as research tools to develop other new materials and processes. Intense, pulsed magnet fields are currently being used in nuclear fusion research to contain the hot, reacting nuclear plasma that would otherwise melt any solid material vessel. Magnetic fields can also be used in materials research to study the behavior of semiconductors used in electronics to determine the effects of making micro-sized integrated circuits.

Where To Learn More

Books

Brady, George S. and Henry R. Clauser. Materials Handbook, 12th Ed. McGraw-Hill, 1986.
Braithwaite, Nicholas and Graham Weaver, eds. Electronic Materials. Butterworths, 1990.
Campbell, Peter. Permanent Magnet Materials and Their Design. Cambridge University Press, 1994.
Verschuur, Gerrit L. Hidden Attraction: The History and Mystery of Magnetism. Oxford University Press, 1993.

Periodicals

Boebinger, Greg, Al Passner, and Joze Bevk. "Building World-Record Magnets." Scientific American, June 1995, pp. 58-66.
Duplessis, John. "An Attractive Proposition." Machine Design, June 11, 1993, p. 46.

— Chris Cavette

List of Padma Awardees - 2012

Following are the winners of the country's highest civilian awards this year :

Padma Vibhushan

No Name Discipline State 1.        K G Subramanyan Art-Painting & Sculpture West Bengal 2.        Late (Dr.)Bhupen Hazarika Art- Vocal Music Assam 3.        Late Shri Mario De Miranda Art-Cartoonist Goa 4.        Dr. Kantilal Hastimal Sancheti Medicine - Orthopedics Maharashtra 5.        T V Rajeswar Civil Service Delhi

Padma Bhushan

No Name Discipline State 1.         Smt. Shabana Azmi Art - Cinema Maharashtra 2.         Jatin Das Art - Painting Delhi 3.         Khaled Choudhury Art - Theatre West Bengal 4.         Pandit Buddhadev Das Gupta Art - Instrumental Music - Sarod West Bengal 5.         Dr. Trippunithwra Viswanathan Gopalkrishnan Art - Classical vocal and instrumental music Tamil Nadu 6.         Dharmendra Singh Deol alias Dharmendra Art - Cinema Maharashtra 7.         Ms. Mira Nair Art - Cinema Delhi 8.         M.S. Gopalakrishnan Art - Instrumental Music-Violin Tamil Nadu 9.         Satya Narayan Goenka Social Work Maharashtra 10.         Dr. (Judge) Patibandla Chandrasekhar Rao Public Affairs Germany 11.         Anish Kapoor Art - Sculpture UK 12.         George Yong-Boon Yeo Public Affairs Singapore 13.         Prof. Shashikumar Chitre Science and Engineering Maharashtra 14.         Subbiah Murugappa Vellayan Trade and Industry Tamil Nadu 15.         Balasubramanian Muthuraman Trade and Industry Maharashtra 16.         Dr. M S Raghunathan Science and Engineering Maharashtra 17.         Dr. Suresh H. Advani Medicine - Oncology Maharashtra 18.         Dr. Devi Prasad Shetty Medicine-Cardiology Karnataka 19.         Prof. (Dr.) Shantaram Balwant Mujumdar Literature and Education Maharashtra 20.         Ronen Sen Civil Service West Bengal 21.         Dr. Homi K. Bhabha Literature and Education UK 22.         Dr. Noshir H Wadia Medicine-Neurology Maharashtra 23.         Prof. Vidya Dehejia Literature and Education USA 24.         Prof. Arvind Panagariya Literature and Education    USA 25.         Dr. Jose Pereira Literature and Education USA 26.         N Vittal Civil Service Kerala 27.         Mata Prasad Civil Service Uttar Pradesh

Padma Shri

No Name Discipline State 1.        Vanraj Bhatia Art - Music Maharashtra 2.        Zia Fariduddin Dagar Art - Music - vocal Maharashtra 3.        Smt. Nameirakpam Ibemni Devi Art - Music- Khongjom Parba Manipur 4.        Ramachandra Subraya Hegde Chittani Art - Yakshagana dance drama Karnataka 5.        Moti Lal Kemmu Art - Playwright Jammu and Kashmir 6.        Smt. R. Nagarathnamma Art - Theatre Karnataka 7.        Kalamandalm Sivan Nambootiri Art - Indian Classical Dance- Kutiyattam Kerala 8.        Smt. Yamunabai Waikar Art - Indian Folk Music-Lavani Maharashtra 9.        Satish Alekar Art - Playwright Maharashtra 10.         Pandit Gopal Prasad Dubey Art - Chhau dance and choreography Jharkhand 11.         Ramakant Gundecha Art - Indian Classical Music- Vocal Madhya Pradesh 12.         Shahid Parvez Khan Art - Instrumental Music-Sitar Maharashtra 13.         Mohan Lal Kumhar Art - Terracotta Rajasthan 14.         Sakar Khan Manganiar Art - Rajasthani Folk Music Rajasthan 15.         Smt. Joy Michael Art - Theatre Delhi 16.         Dr. Minati Mishra Art - Indian Classical Dance-Odissi Orissa 17.         Natesan Muthuswamy Art - Theatre Tamil Nadu 18.         Umakant Gundecha Art - Indian Classical Music- Vocal Madhya Pradesh 19.         Anup Jalota Art-Indian Classical Music- Vocal Maharashtra 20.         Soman Nair Priyadarsan Art - Cinema- Direction Kerala 21.         Sunil Janah Art-Photography Assam 22.         Ms. Laila Tyebji Art-Handicrafts Delhi 23.         Vijay Sharma Art-Painting Himachal Pradesh 24.         Smt. Shamshad Begum Social Work Chattisgarh 25.         Niranjan Pranshankar Pandya Social Work Maharashtra 26.         Dr. Uma Tuli Social Work Delhi 27.         Sat Paul Varma Social Work Jammu and Kashmir 28.         Smt.Binny Yanga Social Work Arunachal Pradesh 29.         Yezdi Hirji Malegam Public Affairs Maharashtra 30.         Pravin H. Parekh Pubic Affairs Delhi 31.         Smt. Reeta Devi Social Work Delhi 32.         Dr. P.K. Gopal Social Work Tamil Nadu 33.         Smt. Phoolbasan Bai Yadav Social Work Chattisgarh 34.         Dr. G. Muniratnam Social Work Andhra Pradesh 35.         Dr. V. Adimurthy Science and Engineering Kerala 36.         Dr. Krishna Lal Chadha Science and Engineering - Agriculture Delhi 37.         Prof. Virander Singh Chauhan Science and Engineering Delhi 38.         Prof. Rameshwar Nath Koul Bamezai Science and Engineering Jammu and Kashmir 39.         Shoji Shiba Trade and Industry Japan 40.         Gopinath Pillai Trade and Industry Singapore 41.         Arun Hastimal Firodia Trade and Industry Maharashtra 42.         Dr. Swati A. Piramal Trade and Industry Maharashtra 43.         Prof. Mahdi Hasan Medicine-Anatomy Uttar Pradesh 44.         Dr. Vijaypal Singh Science and Engineering - Agricultural Research Uttar Pradesh 45.         Dr. Lokesh Kumar Singhal Science and Engineering Punjab 46.         Dr. Yagnaswami Sundara Rajan Science and Engineering Karnataka 47.         Prof. Jagadish Shukla Science and Engineering USA 48.         Ms. Priya Paul Trade and Industry Delhi 49.         Dr. Viswanathan Mohan Medicine - Diabetology Tamil Nadu 50.         Dr. J. Hareendran Nair Medicine - Ayurveda Kerala 51.         Dr. Vallalarpuram Sennimalai Natarajan Medicine - Geriatrics Tamil Nadu 52.         Dr. Jitendra Kumar Singh Medicine - Oncology Bihar 53.         Surjit Singh Patar Literature and Education - Poetry Punjab 54.         Vijay Dutt Shridhar Literature and Education - Journalism Madhya Pradesh 55.         Irwin Allan Sealy Literature and Education Uttarakhand 56.         Ms. Geeta Dharmarajan Literature and Education Delhi 57.         Prof. Sachchidanand Sahai Literature and Education Haryana 58.         Smt. Pepita Seth Literature and Education Kerala 59.         Dr. Ralte L. Thanmawia Literature and Education Mizoram 60.         Dr. Shrinivas S. Vaishya Medicine-Healthcare Daman and Diu 61.         Dr. Nitya Anand Medicine - Drugs Research Uttar Pradesh 62.         Late Dr. Jugal Kishore Medicine - Homoeopathy Delhi 63.         Dr. Mukesh Batra Medicine-Homeopathy Maharashtra 64.         Dr. Eberhard Fischer Literature and Education Switzerland 65.         Kedar Gurung Literature and Education Sikkim 66.         Ajeet Bajaj Sports - Skiing Delhi 67.         Smt. Jhulan Goswami Sports - Women's Cricket West Bengal 68.         Zafar Iqbal Sports-Hockey Uttar Pradesh 69.         Devendra Jhajrija Sports - Athletics- Paralympics Rajasthan 70.         Limba Ram Sports - Archery Rajasthan 71.         Syed Mohammed Arif Sports - Badminton Andhra Pradesh 72.         Prof. Ravi Chaturvedi Sports- Commentary Delhi 73.         Prabhakar Vaidya Sports-Physical Education Maharashtra 74.         T. Venkatapathi Reddiar Others-Horticulture Puducherry 75.         Dr. K. (Kota) Ullas Karanth Others-Wildlife Conservation and Environment Protection Karnataka 76.         K Paddayya Others-Archaeology Maharashtra 77. Swapan Guha Others-Ceramics  Rajasthan          Dr. Kartikeya V. Sarabhai Others - Environmental Education Gujarat