text
stringlengths 8
2.84k
| source
stringlengths 13
140
|
|---|---|
States Patent and Trademark Office On March 10, Bell succeeded in getting his telephone to work, using a liquid transmitter similar to Gray'sdesign. Vibration of the diaphragm caused a needle to vibrate in the water, varying the electrical resistance in the circuit. When Bell spoke the sentence "Mr. Watson Come here I want to see you" into the liquid transmitter, Watson, listening at the receiving end in an adjoining room, heard the words clearly. Although Bell was, and still is, accused of stealing the telephone from Gray, Bell used Gray'swater transmitter design only after Bell'spatent had been granted, and only as a proof of concept scientific experiment, to prove to his own satisfaction that intelligible "articulate speech" (Bell'swords) could be electrically transmitted. After March 1876, Bell focused on improving the electromagnetic telephone and never used Gray'sliquid transmitter in public demonstrations or commercial use. The examiner raised the question of priority for the variable resistance feature of the telephone before approving Bell'spatent application. He told Bell that his claim for the variable resistance feature was also described in Gray'scaveat. Bell pointed to a variable resistance device in his previous application in which he described a cup of mercury, not water. He had filed the mercury application at the patent office on February 25, 1875, long before Gray described the water device. In addition, Gray abandoned his caveat, and because he did not contest Bell'spriority, the examiner approved Bell'spatent on March 3, 1876. Gray had reinvented the variable resistance telephone, but Bell was the first to write down the idea and test it in a telephone. The Patent clerk Later developments On March 10, 1876, Bell used "the instrument" in Boston to call Thomas Watson who was in another room but out of earshot. He said, "Mr. Watson, come here – I want to see you" and Watson soon appeared at his side. Continuing his experiments in Brantford, Bell brought home a working model of his | Wikipedia:Alexander Graham Bell |
was in another room but out of earshot. He said, "Mr. Watson, come here – I want to see you" and Watson soon appeared at his side. Continuing his experiments in Brantford, Bell brought home a working model of his telephone. On August 3, 1876, from the telegraph office in Brantford, Bell sent a telegram to the village of Mount Pleasant away, indicating that he was ready. He made a telephone call via telegraph wires and faint voices were heard replying. The following night, he amazed guests as well as his family with a call between the Bell Homestead and the office of the Dominion Telegraph Company in Brantford along an improvised wire strung up along telegraph lines and fences, and laid through a tunnel. This time, guests at the household distinctly heard people in Brantford reading and singing. The third test, on August 10, 1876, was made via the telegraph line between Brantford and Paris, Ontario, away. This test is said by many sources to be the "world'sfirst long-distance call". It proved that the telephone could work over long distances, at least as a one-way call. The first two-way (reciprocal) conversation over a line occurred between Cambridge and Boston (roughly 2.5 miles) on October 9, 1876. During that conversation, Bell was on Kilby Street in Boston and Watson was at the offices of the Walworth Manufacturing Company. Bell and his partners, Hubbard and Sanders, offered to sell the patent outright to Western Union for $100,000, equal to $ today, but it did not work (according to an apocryphal story, the president of Western Union balked, countering that the telephone was nothing but a toy). Two years later, he told colleagues that if he could get the patent for $25 million (equal to $ today), he would consider it a bargain. By then, the Bell company no longer wanted to sell the patent. Bell'sinvestors became millionaires while he fared well from residuals | Wikipedia:Alexander Graham Bell |
if he could get the patent for $25 million (equal to $ today), he would consider it a bargain. By then, the Bell company no longer wanted to sell the patent. Bell'sinvestors became millionaires while he fared well from residuals and at one point had assets of nearly $1 million. Bell began a series of public demonstrations and lectures to introduce the new invention to the scientific community as well as the general public. A short time later, Bell Telephone Company#Early promotional success On January 14, 1878, at Osborne House, on the Isle of Wight, Bell demonstrated the device to Queen Victoria, placing calls to Cowes, Southampton, and London. These were the first publicly witnessed long-distance telephone calls in the UK. The queen found the process "quite extraordinary" although the sound was "rather faint". She later asked to buy the equipment that was used, but Bell offered to make "a set of telephones" specifically for her. The Bell Telephone Company was created in 1877, and by 1886, more than 150,000 people in the U.S. owned telephones. Bell Company engineers made numerous other improvements to the telephone, which emerged as one of the most successful products ever. In 1879, the company acquired Edison'spatents for the carbon microphone from Western Union. This made the telephone practical for longer distances, and it was no longer necessary to shout to be heard at the receiving telephone. Pedro II of Brazil was the first person to buy stock in the Bell Telephone Company. One of the first telephones in a private residence was installed in his palace in Petrópolis, his summer retreat from Rio de Janeiro. In January 1915, Bell made the first ceremonial transcontinental telephone call. Calling from the AT&T head office at 15 Dey Street in New York City, Bell was heard by Thomas A. Watson Competitors As is sometimes common in scientific discoveries, simultaneous developments occurred, as evidenced by a number of inventors | Wikipedia:Alexander Graham Bell |
Calling from the AT&T head office at 15 Dey Street in New York City, Bell was heard by Thomas A. Watson Competitors As is sometimes common in scientific discoveries, simultaneous developments occurred, as evidenced by a number of inventors who were at work on the telephone. Over 18 years, the Bell Telephone Company faced 587 court challenges to its patents, including five that went to the Supreme Court of the United States On January 13, 1887, the U.S. government moved to annul the patent issued to Bell on the grounds of fraud and misrepresentation. After a series of decisions and reversals, the Bell company won a decision in the Supreme Court, though a couple of the original claims from the lower court cases were left undecided. By the time the trial had wound its way through nine years of legal battles, the U.S. prosecuting attorney had died and the two Bell patents (No. 174,465, dated March 7, 1876, and No. 186,787, dated January 30, 1877) were no longer in effect, although the presiding judges agreed to continue the proceedings due to the case'simportance as a stare decisis During a deposition filed for the 1887 trial, Italian inventor Antonio Meucci also claimed to have created the first working model of a telephone in Italy in 1834. In 1886, in the first of three cases in which he was involved, The value of Bell'spatent was acknowledged throughout the world, and patent applications were made in most major countries. When Bell delayed the German patent application, the electrical firm Siemens & Halske set up a rival manufacturer of Bell telephones under its own patent. Siemens produced near-identical copies of the Bell telephone without having to pay royalties. The establishment of the International Bell Telephone Company in Brussels, Belgium, in 1880, as well as a series of agreements in other countries eventually consolidated a global telephone operation. The strain put on Bell by his constant | Wikipedia:Alexander Graham Bell |
to pay royalties. The establishment of the International Bell Telephone Company in Brussels, Belgium, in 1880, as well as a series of agreements in other countries eventually consolidated a global telephone operation. The strain put on Bell by his constant appearances in court, necessitated by the legal battles, eventually resulted in his resignation from the company. Family life , and their daughters Elsie (left) and Marian ca. 1885 On July 11, 1877, a few days after the Bell Telephone Company was established, Bell married Mabel Gardiner Hubbard * Elsie May Bell (1878–1964) who married Gilbert Hovey Grosvenor of National Geographic Society * Marian Hubbard Bell (1880–1962) who was referred to as "Daisy". Married David Fairchild. Bell wrote: "Only think * Two sons who died in infancy (Edward in 1881 and Robert in 1883). The Bell family home was in Cambridge, Massachusetts, until 1880 when Bell'sfather-in-law bought a house in Washington, D.C.; in 1882 he bought a home in the same city for Bell'sfamily, so they could be with him while he attended to the numerous court cases involving patent disputes. Bell was a British subject throughout his early life in Scotland and later in Canada until 1882 when he became a naturalized citizen of the United States. In 1915, he characterized his status as: "I am not one of those hyphenated Americans who claim allegiance to two countries." Despite this declaration, Bell has been proudly claimed as a "native son" by all three countries he resided in: the United States, Canada, and the United Kingdom. By 1885, a new summer retreat was contemplated. That summer, the Bells had a vacation on Cape Breton Island in Nova Scotia, Canada, spending time at the small village of Baddeck, Nova Scotia Until the end of his life, Bell and his family would alternate between the two homes, but Beinn Bhreagh would, over the next 30 years, become more than a summer home as Bell became | Wikipedia:Alexander Graham Bell |
small village of Baddeck, Nova Scotia Until the end of his life, Bell and his family would alternate between the two homes, but Beinn Bhreagh would, over the next 30 years, become more than a summer home as Bell became so absorbed in his experiments that his annual stays lengthened. Both Mabel and Bell became immersed in the Baddeck community and were accepted by the villagers as "their own". The Bells were still in residence at Beinn Bhreagh when the Halifax Explosion occurred on December 6, 1917. Mabel and Bell mobilized the community to help victims in Halifax. Later inventions Although Alexander Graham Bell is most often associated with the invention of the telephone, his interests were extremely varied. According to one of his biographers, Charlotte Gray (author) Bell worked extensively in medical research and invented techniques for teaching speech to the deaf. During his Volta Laboratory and Bureau Bell's own home used a primitive form of air conditioning, in which fans blew currents of air across great blocks of ice. He also anticipated modern concerns with fuel shortages and industrial pollution. Methane gas, he reasoned, could be produced from the waste of farms and factories. At his Canadian estate in Nova Scotia, he experimented with composting toilets and devices to capture water from the atmosphere. In a magazine article published in 1917, he reflected on the possibility of using solar energy to heat houses. Photophone system, ca. 1880 Bell and his assistant Charles Sumner Tainter jointly invented a wireless telephone, named a photophone, which allowed for the transmission of both sounds and normal human conversations on a beam of light. Both men later became full associates in the Volta Laboratory and Bureau#Laboratory projects On June 21, 1880, Bell'sassistant transmitted a wireless voice telephone message a considerable distance, from the roof of the Franklin School (Washington, D.C.) Bell believed the photophone'sprinciples were his life's "greatest achievement", telling a reporter shortly before his | Wikipedia:Alexander Graham Bell |
Bureau#Laboratory projects On June 21, 1880, Bell'sassistant transmitted a wireless voice telephone message a considerable distance, from the roof of the Franklin School (Washington, D.C.) Bell believed the photophone'sprinciples were his life's "greatest achievement", telling a reporter shortly before his death that the photophone was "the greatest invention [I have] ever made, greater than the telephone". The photophone was a precursor to the fiber-optic communication systems which achieved popular worldwide usage in the 1980s. Its master patent was issued in December 1880, many decades before the photophone'sprinciples came into popular use. Metal detector Bell is also credited with developing one of the early versions of a metal detector through the use of an induction balance, after the Assassination of James A. Garfield Bell's own detailed account, presented to the American Association for the Advancement of Science in 1882, differs in several particulars from most of the many and varied versions now in circulation, by concluding that extraneous metal was not to blame for failure to locate the bullet. Perplexed by the peculiar results he had obtained during an examination of Garfield, Bell "proceeded to the White House Hydrofoils on a test run ca. 1919 The March 1906 Scientific American article by American pioneer William E. Meacham explained the basic principle of hydrofoils and Hydroplane (boat) During his world tour of 1910–11, Bell and Baldwin met with Forlanini in France. They had rides in the Forlanini hydrofoil boat over Lake Maggiore. Baldwin described it as being as smooth as flying. On returning to Baddeck, a number of initial concepts were built as experimental models, including the Dhonnas Beag (Scottish Gaelic for 'little devil'), the first self-propelled Bell-Baldwin hydrofoil. The experimental boats were essentially proof-of-concept prototypes that culminated in the more substantial HD-4, powered by Renault engines. A top speed of was achieved, with the hydrofoil exhibiting rapid acceleration, good stability, and steering, along with the ability to take waves without difficulty. In 1913, | Wikipedia:Alexander Graham Bell |
proof-of-concept prototypes that culminated in the more substantial HD-4, powered by Renault engines. A top speed of was achieved, with the hydrofoil exhibiting rapid acceleration, good stability, and steering, along with the ability to take waves without difficulty. In 1913, Dr. Bell hired Walter Pinaud, a Sydney yacht designer and builder as well as the proprietor of Pinaud's Yacht Yard in Westmount, Nova Scotia, to work on the pontoons of the HD-4. Pinaud soon took over the boatyard at Bell Laboratories on Beinn Bhreagh, Bell'sestate near Baddeck, Nova Scotia. Pinaud'sexperience in boatbuilding enabled him to make useful design changes to the HD-4. After the First World War, work began again on the HD-4. Bell'sreport to the United States Navy Aeronautics In 1891, Bell had begun experiments to develop motor-powered heavier-than-air aircraft. The AEA was first formed as Bell shared the vision to fly with his wife, who advised him to seek "young" help as Bell was at the age of 60. In 1898, Bell experimented with tetrahedral box kites and wings constructed of multiple compound tetrahedral kites covered in maroon silk. Hargrave declined to take patents on his inventions, similar to Bell'sdecision not to file patents on some of his inventions. Bell also chose maroon-coloured silk as it would show up clearly against the light-coloured sky in his photographic studies. Bell was a supporter of aerospace engineering research through the Aerial Experiment Association (AEA), officially formed at Baddeck, Nova Scotia, in October 1907 at the suggestion of his wife Mabel Gardiner Hubbard The AEA'swork progressed to heavier-than-air machines, applying their knowledge of kites to gliders. Moving to Hammondsport, the group then designed and built the AEA Red Wing Their final aircraft design, the AEA Silver Dart Heredity and genetics Bell, along with many members of the scientific community at the time, took an interest in the popular science of heredity which grew out of the publication of Charles Darwin'sbook On the Origin | Wikipedia:Alexander Graham Bell |
the AEA Silver Dart Heredity and genetics Bell, along with many members of the scientific community at the time, took an interest in the popular science of heredity which grew out of the publication of Charles Darwin'sbook On the Origin of Species in 1859. On his estate in Nova Scotia, Bell conducted meticulously recorded breeding experiments with rams and ewes. Over the course of more than 30 years, Bell sought to produce a breed of sheep with multiple nipples that would bear twins. He specifically wanted to see if selective breeding could produce sheep with four functional nipples with enough milk for twin lambs. This interest in animal breeding caught the attention of scientists focused on the study of heredity and genetics in humans. In November 1883, Bell presented a paper at a meeting of the National Academy of Sciences titled Upon the Formation of a Deaf Variety of the Human Race. The paper is a compilation of data on the hereditary aspects of deafness. Bell'sresearch indicated that a hereditary tendency toward deafness, as indicated by the possession of deaf relatives, was an important element in determining the production of deaf offspring. He noted that the proportion of deaf children born to deaf parents was many times greater than the proportion of deaf children born to the general population. In the paper, Bell delved into social commentary and discussed hypothetical public policies to bring an end to deafness. He also criticized educational practices that segregated deaf children rather than integrated them fulling into mainstream classrooms. The paper did not propose sterilization of deaf people or prohibition on intermarriage, noting that "We cannot dictate to men and women whom they should marry and natural selection no longer influences mankind to any great extent." The paper'sauthor concludes by saying "A wiser way to prevent the extension of hereditary deafness, it seems to us, would be to continue the investigations which Dr. Bell has so | Wikipedia:Alexander Graham Bell |
natural selection no longer influences mankind to any great extent." The paper'sauthor concludes by saying "A wiser way to prevent the extension of hereditary deafness, it seems to us, would be to continue the investigations which Dr. Bell has so admirable begun until the laws of the transmission of the tendency to deafness are fully understood, and then by explaining those laws to the pupils of our schools to lead them to choose their partners in marriage in such a way that deaf-mute offspring will not be the result." Bell'sinterest and research on heredity attracted the interest of Charles Davenport, a Harvard professor and head of the Cold Spring Harbor Laboratory. In 1906, Davenport, who was also the founder of the American Genetic Association On learning of Bell'sdeath, the Prime Minister of Canada Alexander Graham Bell was buried atop Beinn Bhreagh mountain, on his estate where he had resided increasingly for the last 35 years of his life, overlooking Bras d'Or Lake. Legacy and honours in front of the Bell Telephone Building of Brantford, Ontario, The Telephone City. Honours and tributes flowed to Bell in increasing numbers as his invention became ubiquitous and his personal fame grew. Bell received numerous honorary degrees from colleges and universities to the point that the requests almost became burdensome. During his life, he also received dozens of major awards, medals, and other tributes. These included statuary monuments to both him and the new form of communication his telephone created, including the Bell Telephone Memorial erected in his honour in Alexander Graham Bell Gardens in Brantford, Ontario, in 1917. (in Manitoba Canada and North Dakota, USA) A large number of Bell'swritings, personal correspondence, notebooks, papers, and other documents reside in both the United States Library of Congress * The Bell Homestead National Historic Site, includes the Bell family home, "Melville House", and farm overlooking Brantford, Ontario and the Grand River (Ontario) * Canada'sfirst telephone company building, the | Wikipedia:Alexander Graham Bell |
documents reside in both the United States Library of Congress * The Bell Homestead National Historic Site, includes the Bell family home, "Melville House", and farm overlooking Brantford, Ontario and the Grand River (Ontario) * Canada'sfirst telephone company building, the "Henderson Home" of the late 1870s, a predecessor of the Bell Canada * The Alexander Graham Bell Memorial Park, which features a broad neoclassical monument built in 1917 by public subscription. The monument depicts mankind'sability to span the globe through telecommunications; * The Alexander Graham Bell Museum (opened in 1956), part of the Alexander Graham Bell National Historic Site which was completed in 1978 in Baddeck, Nova Scotia. Many of the museum'sartifacts were donated by Bell'sdaughters., Cape Breton Island In 1880, Bell received the Volta Prize with a purse of 50,000 French francs (approximately US$ in today'scurrency) for the invention of the telephone from the French government. Among the luminaries who judged were Victor Hugo and Alexandre Dumas, fils The Volta Laboratory became an experimental facility devoted to scientific discovery, and the very next year it improved Edison'sphonograph by substituting wax for tinfoil as the recording medium and incising the recording rather than indenting it, key upgrades that Edison himself later adopted. The laboratory was also the site where he and his associate invented his "proudest achievement", "the photophone", the "optical telephone" which presaged Fiber-optic communication In partnership with Gardiner Greene Hubbard, Bell helped establish the publication Science (journal) The bel (B) and the smaller decibel'' (dB) are units of measurement of Sound pressure In 1936, the United States Patent and Trademark Office The 150th anniversary of Bell'sbirth in 1997 was marked by a special issue of The Royal Bank of Scotland £1 note Alexander Graham Bell was ranked 57th among the 100 Greatest Britons (2002) in an official BBC nationwide poll, and among the The Greatest Canadian , Scotland, receiving an honorary Doctor of Laws degree (LL.D.) at the university in | Wikipedia:Alexander Graham Bell |
£1 note Alexander Graham Bell was ranked 57th among the 100 Greatest Britons (2002) in an official BBC nationwide poll, and among the The Greatest Canadian , Scotland, receiving an honorary Doctor of Laws degree (LL.D.) at the university in 1906 Honorary degrees Alexander Graham Bell, who could not complete the university program of his youth, received at least a dozen honorary degrees from academic institutions, including eight honorary Doctor of Laws * Gallaudet College (then named National Deaf-Mute College) in Washington, D.C. (Ph.D.) in 1880 * University of Würzburg in Würzburg, Bavaria (Ph.D.) in 1882 * Heidelberg University in Heidelberg, Germany (M.D.) in 1886 * Harvard University in Cambridge, Massachusetts (LL.D.) in 1896 * Illinois College, in Jacksonville, Illinois (LL.D.) in 1896, possibly 1881 * Amherst College in Amherst, Massachusetts (LL.D.) in 1901 * University of St Andrews in St Andrews, Scotland (LL.D) in 1902 * University of Oxford in Oxford, England (D.Sc.) in 1906 * University of Edinburgh in Edinburgh, Scotland (LL.D.) in 1906 * The George Washington University in Washington, D.C. (LL.D.) in 1913 * Queen's University at Kingston in Kingston, Ontario, Canada (LL.D.) in 1908 * Dartmouth College in Hanover, New Hampshire (LL.D.) in 1913, possibly 1914 Portrayal in film, television and fiction * The 1939 film The Story of Alexander Graham Bell was based on his life and works. * Eyewitness No. 90 A Great Inventor Is Remembered, a 1957 National Film Board of Canada * The 1965 BBC miniseries Alexander Graham Bell starring Alec McCowen and Francesca Annis. * The 1992 film The Sound and the Silence was a TV film. * Biography (TV series) * John Tench portrays Bell five times in the CBC | Wikipedia:Alexander Graham Bell |
Television * A Sign of Her Own,'' by Sarah Marsh (2024), a novel about a pupil of Bell's Visible Speech, who is "gradually realising and acting upon the harm he was inflicting on her and other deaf people." Bibliography * Also | Wikipedia:Alexander Graham Bell |
* A Sign of Her Own,'' by Sarah Marsh (2024), a novel about a pupil of Bell's Visible Speech, who is "gradually realising and acting upon the harm he was inflicting on her and other deaf people." Bibliography * Also published as: * * See also * Alexander Graham Bell Association for the Deaf and Hard of Hearing * Alexander Graham Bell National Historic Site * Bell Boatyard * Bell Homestead National Historic Site * Bell Telephone Memorial * Emile Berliner * Charles Bourseul * IEEE Alexander Graham Bell Medal * Innocenzo Manzetti * Antonio Meucci * Oriental Telephone Company * List of people on banknotes#Scotland * Pioneers, a Volunteer Network * Johann Philipp Reis * The Story of Alexander Graham Bell, a 1939 movie of his life * The Telephone Cases * Volta Laboratory and Bureau References Notes Citations Further reading * Mullett, Mary B. The Story of A Famous Inventor. New York: Rogers and Fowle, 1921. * Walters, Eric. The Hydrofoil Mystery. Toronto, Ontario, Canada: Penguin Books * Winzer, Margret A. The History Of Special Education: From Isolation To Integration. Washington, D.C.: Gallaudet University Press, 1993. . External links * Alexander and Mabel Bell Legacy Foundation * Alexander Graham Bell Institute at Cape Breton University (archived 8 December 2015) * Bell Telephone Memorial, Brantford, Ontario * Bell Homestead National Historic Site, Brantford, Ontario * Alexander Graham Bell National Historic Site of Canada, Baddeck, Nova Scotia * Alexander Graham Bell Family Papers at the Library of Congress * * Biography at the Dictionary of Canadian Biography Online * Science.ca profile: Alexander Graham Bell * * * Alexander Graham Bell'snotebooks at the Internet Archive * "Téléphone et photophone : les contributions indirectes de Graham Bell à l'idée de la vision à distance par l'électricité" at the Histoire de la télévision * * Alexander Graham Bell and the Aerial Experiment Association Photograph Collection at The Museum of Flight (Seattle, Washington). Multimedia | Wikipedia:Alexander Graham Bell |
contributions indirectes de Graham Bell à l'idée de la vision à distance par l'électricité" at the Histoire de la télévision * * Alexander Graham Bell and the Aerial Experiment Association Photograph Collection at The Museum of Flight (Seattle, Washington). Multimedia * Alexander Graham Bell at The Biography Channel * * * * * Shaping The Future, from the Heritage Minutes and Radio Minutes collection at Historica Canada Category:Alexander Graham Bell Category:1847 births Category:1922 deaths Category:19th-century Scottish inventors Category:19th-century Canadian inventors Category:19th-century Canadian scientists Category:19th-century Scottish businesspeople Category:19th-century Scottish scientists Category:19th-century Scottish engineers Category:20th-century American inventors Category:20th-century American scientists Category:20th-century Canadian scientists Category:Alumni of the University of Edinburgh Category:Alumni of University College London Category:American agnostics Category:American educational theorists Category:American Eugenics Society members Category:American physicists Category:American recipients of the Legion of Honour Category:American Unitarians Category:Articles containing video clips Category:Aviation pioneers Category:Businesspeople from Boston Category:Canadian activists Category:Canadian agnostics Category:Canadian Aviation Hall of Fame inductees Category:Canadian educational theorists Category:Canadian emigrants to the United States Category:Canadian eugenicists Category:Canadian physicists Category:Canadian Unitarians Category:Deaths from diabetes in Canada Category:Fellows of the American Academy of Arts and Sciences Category:Gardiner family Category:George Washington University trustees Category:Hall of Fame for Great Americans inductees Category:History of telecommunications Category:IEEE Edison Medal recipients Category:John Fritz Medal recipients Category:Language teachers Category:Members of the American Philosophical Society Category:Members of the United States National Academy of Sciences Category:National Aviation Hall of Fame inductees Category:National Geographic Society Category:Officers of the Legion of Honour Category:People educated at the Royal High School, Edinburgh Category:People from | Wikipedia:Alexander Graham Bell |
Baddeck, Nova Scotia Category:People from Brantford Category:Scientists from Edinburgh Category:Scientists from Washington, D.C. Category:Scottish agnostics Category:Scottish emigrants to Canada Category:Scottish emigrants to the United States Category:Scottish Engineering Hall of Fame inductees Category:Scottish eugenicists Category:Scottish physicists Category:Scottish Unitarians Category:Smithsonian Institution people | Wikipedia:Alexander Graham Bell |
Apple Inc. is an American multinational corporation and technology company headquartered in Cupertino, California, in Silicon Valley. It is best known for its consumer electronics, computer software The company was founded to produce and market Wozniak's Apple I personal computer. Its second computer, the Apple II (original) List of Apple products Apple Criticism of Apple Inc. History 1976–1980: Founding and incorporation and Steve Wozniak co-founded Apple in Jobs'sparents' home on Crist Drive in Los Altos, California. Wozniak called the popular belief that the company was founded in the garage "a bit of a myth", although they moved some operations to the garage when the bedroom became too crowded. is Apple'sfirst product, designed by Wozniak and sold as an assembled circuit board without the required keyboard, monitor, power supply, and the optional case. Apple Computer Company was founded on April 1, 1976, by Steve Jobs, Steve Wozniak, and Ronald Wayne as a partnership. The company'sfirst product is the Apple I, a computer designed and hand-built entirely by Wozniak. To finance its creation, Jobs sold his Volkswagen Type 2 Apple Computer, Inc. was incorporated in Cupertino, California, without Wayne, who had left and sold his share of the company back to Jobs and Wozniak for $800 only twelve days after having co-founded it. Multimillionaire Mike Markkula provided essential business expertise and funding of to Jobs and Wozniak during the incorporation of Apple. During the first five years of operations, revenue grew exponentially, doubling about every four months. Between September 1977 and September 1980, yearly sales grew from $775,000 to million, an average annual growth rate of 533%. The Apple II (1977 computer) , introduced in 1977 and designed primarily by Wozniak, was the company'sfirst major success. The Apple II was chosen to be the desktop platform for the first killer application of the business world: VisiCalc, a spreadsheet computer program On December 12, 1980, Apple went public with an | Wikipedia:Apple Inc. |
by Wozniak, was the company'sfirst major success. The Apple II was chosen to be the desktop platform for the first killer application of the business world: VisiCalc, a spreadsheet computer program On December 12, 1980, Apple went public with an initial public offering (IPO) on the fully electronic NASDAQ Stock Market, selling 4.6 million shares at $22 per share ($.10 per share when adjusting for stock splits ), By the end of the day, around 300millionaires were created, including Jobs and Wozniak, from a stock price of $29 per share and a market cap of $1.778billion. Jobs was also hostile to the Apple II division, which at the time, generated most of the company'srevenue. Its debut was signified by "1984 (advertisement) The advertisement created great interest in Macintosh 128K The board of directors instructed Sculley to contain Jobs and his ability to launch expensive forays into untested products. Rather than submit to Sculley'sdirection, Jobs attempted to oust him from leadership. Jean-Louis Gassée informed Sculley that Jobs had been attempting to organize a coup d'état#Other After the departures of Jobs and Wozniak in 1985, Sculley launched the Macintosh 512K that year with quadruple the RAM, and introduced the LaserWriter, the first reasonably priced PostScript laser printer. PageMaker, an early desktop publishing application taking advantage of the PostScript language, was also released by Aldus Corporation in July 1985. It has been suggested that the combination of Macintosh, LaserWriter, and PageMaker was responsible for the creation of the desktop publishing market. This dominant position in the desktop publishing market allowed the company to focus on higher price points, the so-called "high-right policy" named for the position on a chart of price vs. profits. Newer models selling at higher price points offered higher profit margin, and appeared to have no effect on total sales as power users snapped up every increase in speed. Although some worried about pricing themselves out of the market, the high-right policy | Wikipedia:Apple Inc. |
igh-energy beta particles, and astatine does not. Beta particles have much greater penetrating power through tissues | Wikipedia:Astatine |
the extremely toxic polonium-210. The principal medicinal difference between astatine-211 and iodine-131 (a radioactive iodine isotope also used in medicine) is that iodine-131 emits high-energy beta particles, and astatine does not. Beta particles have much greater penetrating power through tissues than do the much heavier alpha particles. An average alpha particle released by astatine-211 can travel up to 70μm through surrounding tissues; an average-energy beta particle emitted by iodine-131 can travel nearly 30 times as far, to about 2mm. The short half-life and limited penetrating power of alpha radiation through tissues offers advantages in situations where the "tumor burden is low and/or malignant cell populations are located in close proximity to essential normal tissues." Animal studies show that astatine, similarly to iodine although to a lesser extent, perhaps because of its slightly more metallic nature is preferentially (and dangerously) concentrated in the thyroid gland. Unlike iodine, astatine also shows a tendency to be taken up by the lungs and spleen, possibly because of in-body oxidation of At– to At+. this conclusion remained controversial for many years. General agreement was later reached that this was likely caused by the effect of breast tissue irradiation combined with hormonal changes due to irradiation of the ovaries. Trace amounts of astatine can be handled safely in fume hoods if they are well-aerated; biological uptake of the element must be avoided. See also * Radiation protection Notes References Bibliography * * * * * * * * External links * Astatine at The Periodic Table of Videos (University of Nottingham) * Astatine: Halogen or Metal? Category:Astatine Category:Chemical elements Category:Chemical elements with face-centered cubic structure Category:Halogens Category:Synthetic elements | Wikipedia:Astatine |
or ). Atoms are the basic particles of the chemical elements. An atom consists of a atomic nucleus Atoms are extremely small, typically around 100picometers across. A human hair is about a million carbon atoms wide. Atoms are smaller than the shortest wavelength of visible light, which means humans cannot see atoms with conventional microscopes. They are so small that accurately predicting their behavior using classical physics is not possible due to quantum mechanics More than 99.9994% of an atom's mass is in the nucleus. Protons have a positive electric charge and neutrons have no charge, so the nucleus is positively charged. The electrons are negatively charged, and this opposing charge is what binds them to the nucleus. If the numbers of protons and electrons are equal, as they normally are, then the atom is electrically neutral as a whole. If an atom has more electrons than protons, then it has an overall negative charge and is called a negative ion (or anion). Conversely, if it has more protons than electrons, it has a positive charge and is called a positive ion (or cation). The electrons of an atom are attracted to the protons in an atomic nucleus by the electromagnetic force. The protons and neutrons in the nucleus are attracted to each other by the nuclear force. This force is usually stronger than the electromagnetic force that repels the positively charged protons from one another. Under certain circumstances, the repelling electromagnetic force becomes stronger than the nuclear force. In this case, the nucleus Nuclear fission Atoms can attach to one or more other atoms by chemical bonds to form chemical compounds such as molecules or crystals. The ability of atoms to attach and detach from each other is responsible for most of the physical changes observed in nature. Chemistry is the science that studies these changes. History of atomic theory In philosophy The basic idea that | Wikipedia:Atom |
to attach and detach from each other is responsible for most of the physical changes observed in nature. Chemistry is the science that studies these changes. History of atomic theory In philosophy The basic idea that matter is made up of tiny indivisible particles is an old idea that appeared in many ancient cultures. The word atom is derived from the ancient Greek word atomos, which means "uncuttable". But this ancient idea was based in philosophical reasoning rather than scientific reasoning. Modern atomic theory is not based on these old concepts. In the early 19th century, the scientist John Dalton found evidence that matter really is composed of discrete units, and so applied the word atom to those units. Dalton's law of multiple proportions In the early 1800s, John Dalton compiled experimental data gathered by him and other scientists and discovered a pattern now known as the "law of multiple proportions". He noticed that in any group of chemical compounds which all contain two particular chemical elements, the amount of Element A per measure of Element B will differ across these compounds by ratios of small whole numbers. This pattern suggested that each element combines with other elements in multiples of a basic unit of weight, with each element having a unit of unique weight. Dalton decided to call these units "atoms". For example, there are two types of tin oxide (disambiguation) Dalton also analyzed iron oxides. There is one type of iron oxide that is a black powder which is 78.1% iron and 21.9% oxygen; and there is another iron oxide that is a red powder which is 70.4% iron and 29.6% oxygen. Adjusting these figures, in the black powder there is about 28g of oxygen for every 100g of iron, and in the red powder there is about 42g of oxygen for every 100g of iron. 28 and 42 form a ratio of 2:3. | Wikipedia:Atom |
figures, in the black powder there is about 28g of oxygen for every 100g of iron, and in the red powder there is about 42g of oxygen for every 100g of iron. 28 and 42 form a ratio of 2:3. Dalton concluded that in these oxides, for every two atoms of iron, there are two or three atoms of oxygen respectively. These substances are known today as iron(II) oxide and iron(III) oxide, and their formulas are FeO and Fe2O3 respectively. Iron(II) oxide'sformula is normally written as FeO, but since it is a crystalline substance we could alternately write it as Fe2O2, and when we contrast that with Fe2O3, the 2:3 ratio for the oxygen is plain to see. As a final example: nitrous oxide is 63.3% nitrogen and 36.7% oxygen, nitric oxide is 44.05% nitrogen and 55.95% oxygen, and nitrogen dioxide is 29.5% nitrogen and 70.5% oxygen. Adjusting these figures, in nitrous oxide there is 80g of oxygen for every 140g of nitrogen, in nitric oxide there is about 160g of oxygen for every 140g of nitrogen, and in nitrogen dioxide there is 320g of oxygen for every 140g of nitrogen. 80, 160, and 320 form a ratio of 1:2:4. The respective formulas for these oxides are nitrous oxide Discovery of the electron In 1897, J. J. Thomson discovered that cathode rays can be deflected by electric and magnetic fields, which meant that cathode rays are not a form of light but made of electrically charged particles, and their charge was negative given the direction the particles were deflected in. He measured these particles to be 1,700 times lighter than hydrogen (the lightest atom). He called these new particles corpuscles but they were later renamed electrons since these are the particles that carry electricity. Thomson also showed that electrons were identical to particles given off by Photoelectric effect Discovery of the nucleus : The extreme scattering of some | Wikipedia:Atom |
but they were later renamed electrons since these are the particles that carry electricity. Thomson also showed that electrons were identical to particles given off by Photoelectric effect Discovery of the nucleus : The extreme scattering of some alpha particles suggested the existence of a nucleus of concentrated charge. The electrons in the atom logically had to be balanced out by a commensurate amount of positive charge, but Thomson had no idea where this positive charge came from, so he tentatively proposed that it was everywhere in the atom, the atom being in the shape of a sphere. This was the mathematically simplest hypothesis to fit the available evidence, or lack thereof. Following from this, Thomson imagined that the balance of electrostatic forces would distribute the electrons throughout the sphere in a more or less even manner. Thomson'smodel is popularly known as the plum pudding model, though neither Thomson nor his colleagues used this analogy. Thomson'smodel was incomplete, it was unable to predict any other properties of the elements such as emission spectra and valency (chemistry) Between 1908 and 1913, Ernest Rutherford and his colleagues Hans Geiger and Ernest Marsden performed a series of experiments in which they bombarded thin foils of metal with a beam of alpha particles. They did this to measure the scattering patterns of the alpha particles. They spotted a small number of alpha particles being deflected by angles greater than 90°. This shouldn'thave been possible according to the Thomson model of the atom, whose charges were too diffuse to produce a sufficiently strong electric field. The deflections should have all been negligible. Rutherford proposed that the positive charge of the atom is concentrated in a tiny volume at the center of the atom and that the electrons surround this nucleus in a diffuse cloud. This nucleus carried almost all of the atom'smass. Only such an intense concentration of charge, anchored by its high mass, could | Wikipedia:Atom |
tiny volume at the center of the atom and that the electrons surround this nucleus in a diffuse cloud. This nucleus carried almost all of the atom'smass. Only such an intense concentration of charge, anchored by its high mass, could produce an electric field that could deflect the alpha particles so strongly. Bohr model A problem in classical mechanics is that an accelerating charged particle radiates electromagnetic radiation, causing the particle to lose kinetic energy. Circular motion counts as acceleration, which means that an electron orbiting a central charge should spiral down into that nucleus as it loses speed. In 1913, the physicist Niels Bohr proposed a new model in which the electrons of an atom were assumed to orbit the nucleus but could only do so in a finite set of orbits, and could jump between these orbits only in discrete changes of energy corresponding to absorption or radiation of a photon. Thomson later found that the positive charge in an atom is a positive multiple of an electron'snegative charge. In 1913, Henry Moseley discovered that the frequencies of X-ray emissions from an excited state These observations led Rutherford to conclude that the hydrogen nucleus is a singular particle with a positive charge equal to the electron'snegative charge. He named this particle "proton" in 1920. The number of protons in an atom (which Rutherford called the "atomic number") was found to be equal to the element'sordinal number on the periodic table and therefore provided a simple and clear-cut way of distinguishing the elements from each other. The atomic weight of each element is higher than its proton number, so Rutherford hypothesized that the surplus weight was carried by unknown particles with no electric charge and a mass equal to that of the proton. In 1928, Walter Bothe observed that beryllium emitted a highly penetrating, electrically neutral radiation when bombarded with alpha particles. It was later discovered that this radiation | Wikipedia:Atom |
particles with no electric charge and a mass equal to that of the proton. In 1928, Walter Bothe observed that beryllium emitted a highly penetrating, electrically neutral radiation when bombarded with alpha particles. It was later discovered that this radiation could knock hydrogen atoms out of paraffin wax. Initially it was thought to be high-energy gamma radiation, since gamma radiation had a similar effect on electrons in metals, but James Chadwick found that the ionization effect was too strong for it to be due to electromagnetic radiation, so long as energy and momentum were conserved in the interaction. In 1932, Chadwick exposed various elements, such as hydrogen and nitrogen, to the mysterious "beryllium radiation", and by measuring the energies of the recoiling charged particles, he deduced that the radiation was actually composed of electrically neutral particles which could not be massless like the gamma ray, but instead were required to have a mass similar to that of a proton. Chadwick now claimed these particles as Rutherford'sneutrons. The current consensus model In 1925, Werner Heisenberg published the first consistent mathematical formulation of quantum mechanics (matrix mechanics). One year earlier, Louis de Broglie had proposed that all particles behave like waves to some extent, and in 1926 Erwin Schrödinger used this idea to develop the Schrödinger equation, which describes electrons as three-dimensional waveforms rather than points in space. A consequence of using waveforms to describe particles is that it is mathematically impossible to obtain precise values for both the point (geometry) Protons have a positive charge and a mass of . The number of protons in an atom is called its atomic number. Ernest Rutherford (1919) observed that nitrogen under alpha-particle bombardment ejects what appeared to be hydrogen nuclei. By 1920 he had accepted that the hydrogen nucleus is a distinct particle within the atom and named it proton. Neutrons have no electrical charge and have a mass of . Neutrons are | Wikipedia:Atom |
ejects what appeared to be hydrogen nuclei. By 1920 he had accepted that the hydrogen nucleus is a distinct particle within the atom and named it proton. Neutrons have no electrical charge and have a mass of . Neutrons are the heaviest of the three constituent particles, but their mass can be reduced by the nuclear binding energy. Neutrons and protons (collectively known as nucleons) have comparable dimensions on the order of although the 'surface' of these particles is not sharply defined. The neutron was discovered in 1932 by the English physicist James Chadwick. In the Standard Model of physics, electrons are truly elementary particles with no internal structure, whereas protons and neutrons are composite particles composed of elementary particles called quarks. There are two types of quarks in atoms, each having a fractional electric charge. Protons are composed of two up quarks (each with charge +) and one down quark (with a charge of −). Neutrons consist of one up quark and two down quarks. This distinction accounts for the difference in mass and charge between the two particles. This is much smaller than the radius of the atom, which is on the order of 105fm. The nucleons are bound together by a short-ranged attractive potential called the residual strong force. At distances smaller than 2.5fm this force is much more powerful than the electrostatic force that causes positively charged protons to repel each other. Atoms of the same chemical element The fusion of two nuclei that create larger nuclei with lower atomic numbers than iron and nickel a total nucleon number of about 60 is usually an exothermic reaction Properties Nuclear properties By definition, any two atoms with an identical number of protons in their nuclei belong to the same chemical element. Atoms with equal numbers of protons but a different number of neutrons are different isotopes of the same element. For example, all hydrogen atoms admit exactly one | Wikipedia:Atom |
identical number of protons in their nuclei belong to the same chemical element. Atoms with equal numbers of protons but a different number of neutrons are different isotopes of the same element. For example, all hydrogen atoms admit exactly one proton, but isotopes exist with no neutrons (hydrogen-1, by far the most common form, For 80 of the chemical elements, at least one stable isotope exists. As a rule, there is only a handful of stable isotopes for each of these elements, the average being 3.1 stable isotopes per element. Twenty-six "monoisotopic elements" have only a single stable isotope, while the largest number of stable isotopes observed for any element is ten, for the element tin. Elements technetium Stability of isotopes is affected by the ratio of protons to neutrons, and also by the presence of certain "magic numbers" of neutrons or protons that represent closed and filled quantum shells. These quantum shells correspond to a set of energy levels within the Nuclear shell model Mass The large majority of an atom'smass comes from the protons and neutrons that make it up. The total number of these particles (called "nucleons") in a given atom is called the mass number. It is a positive integer and dimensionless (instead of having dimension of mass), because it expresses a count. An example of use of a mass number is "carbon-12," which has 12 nucleons (six protons and six neutrons). The actual Invariant mass Shape and size Atoms lack a well-defined outer boundary, so their dimensions are usually described in terms of an atomic radius. This is a measure of the distance out to which the electron cloud extends from the nucleus. This assumes the atom to exhibit a spherical shape, which is only obeyed for atoms in vacuum or free space. Atomic radii may be derived from the distances between two nuclei when the two atoms are joined in a chemical | Wikipedia:Atom |
This assumes the atom to exhibit a spherical shape, which is only obeyed for atoms in vacuum or free space. Atomic radii may be derived from the distances between two nuclei when the two atoms are joined in a chemical bond. The radius varies with the location of an atom on the atomic chart, the type of chemical bond, the number of neighboring atoms (coordination number) and a quantum mechanics When subjected to external forces, like electrical fields, the shape of an atom may deviate from spherical symmetry. The deformation depends on the field magnitude and the orbital type of outer shell electrons, as shown by group theory Atomic dimensions are thousands of times smaller than the wavelengths of light (400–700nanometre Radioactive decay (T) of various isotopes with Z protons and N neutrons. Every element has one or more isotopes that have unstable nuclei that are subject to radioactive decay, causing the nucleus to emit particles or electromagnetic radiation. Radioactivity can occur when the radius of a nucleus is large compared with the radius of the strong force, which only acts over distances on the order of 1fm. Energy levels (5s2 4d10) inclusively. The top of the diagram is lower than an unbound electron state. The potential energy of an electron in an atom is negative number If a bound electron is in an excited state, an interacting photon with the proper energy can cause stimulated emission of a photon with a matching energy level. For this to occur, the electron must drop to a lower energy state that has an energy difference matching the energy of the interacting photon. The emitted photon and the interacting photon then move off in parallel and with matching phases. That is, the wave patterns of the two photons are synchronized. This physical property is used to make lasers, which can emit a coherent beam of light energy in a narrow frequency | Wikipedia:Atom |
move off in parallel and with matching phases. That is, the wave patterns of the two photons are synchronized. This physical property is used to make lasers, which can emit a coherent beam of light energy in a narrow frequency band. The outermost electron shell of an atom in its uncombined state is known as the valence shell, and the electrons in that shell are called valence electrons. The number of valence electrons determines the chemical bond behavior with other atoms. Atoms tend to Chemical reaction Rare and theoretical forms Superheavy elements All nuclides with atomic numbers higher than 82 (lead) are known to be radioactive. No nuclide with an atomic number exceeding 92 (uranium) exists on Earth as a primordial nuclide, and heavier elements generally have shorter half-lives. Nevertheless, an "island of stability" encompassing relatively long-lived isotopes of superheavy elements Predictions for the half-life of the most stable nuclide on the island range from a few minutes to millions of years. In any case, superheavy elements (with Z>104) would not exist due to increasing Coulomb repulsion (which results in spontaneous fission with increasingly short half-lives) in the absence of any stabilizing effects. Exotic matter Each particle of matter has a corresponding antimatter particle with the opposite electrical charge. Thus, the positron is a positively charged antielectron and the antiproton is a negatively charged equivalent of a proton. When a matter and corresponding antimatter particle meet, they annihilate each other. Because of this, along with an imbalance between the number of matter and antimatter particles, the latter are rare in the universe. The first causes of this imbalance are not yet fully understood, although theories of baryogenesis may offer an explanation. As a result, no antimatter atoms have been discovered in nature. > Bibliography * * * * * * * * * * * Further reading * * * * | Wikipedia:Atom |
baryogenesis may offer an explanation. As a result, no antimatter atoms have been discovered in nature. > Bibliography * * * * * * * * * * * Further reading * * * * * * * External links * Atoms in Motion – The Feynman Lectures on Physics * Category:Atoms Category:Chemistry Category:Articles containing video clips | Wikipedia:Atom |
Aluminium (or aluminum in North American English) is a chemical element; it has chemical symbol Chemically, aluminium is a post-transition metal in the boron group; as is common for the group, aluminium forms compounds primarily in the +3 oxidation state. The aluminium cation Al3+ is Fajans' rules The discovery of aluminium was announced in 1825 by Danish physicist Hans Christian Ørsted. The first industrial production of aluminium was initiated by French chemist Henri Étienne Sainte-Claire Deville in 1856. Aluminium became much more available to the public with the Hall–Héroult process developed independently by French engineer Paul Héroult and American engineer Charles Martin Hall in 1886, and the mass production of aluminium led to its extensive use in industry and everyday life. In the World War I Despite its prevalence in the environment, no living organism is known to Metabolism Physical characteristics Isotopes Of aluminium isotopes, only is stable. This situation is common for elements with an odd atomic number. It is the only primordial nuclide All other isotopes of aluminium are radioactive decay The remaining isotopes of aluminium, with mass numbers ranging from 21 to 43, all have half-lives well under an hour. Three metastable states are known, all with half-lives under a minute. Electron shell An aluminium atom has 13 electrons, arranged in an electron configuration of 3s2 3p1 , with three electrons beyond a stable noble gas configuration. Accordingly, the combined first three ionization energy -Annular dark-field imaging A free aluminium atom has a atomic radius Bulk Aluminium metal has an appearance ranging from silvery white to dull gray depending on its surface roughness. Both sides reflect similar amounts of visible light, but the shiny side reflects a far greater share of visible light specular reflection The density of aluminium is 2.70g/cm3, about 1/3 that of steel, much lower than other commonly encountered metals, making aluminium parts easily identifiable through their lightness. Aluminium's | Wikipedia:Aluminium |
the shiny side reflects a far greater share of visible light specular reflection The density of aluminium is 2.70g/cm3, about 1/3 that of steel, much lower than other commonly encountered metals, making aluminium parts easily identifiable through their lightness. Aluminium's low density compared to most other metals arises from the fact that its nuclei are much lighter, while difference in the unit cell size does not compensate for this difference. The only lighter metals are the metals of alkali metal Pure aluminium is quite soft and lacking in strength. In most applications various aluminium alloys are used instead because of their higher strength and hardness. The yield (engineering) Aluminium is an excellent Heat conduction Chemistry Aluminium combines characteristics of pre- and post-transition metals. Since it has few available electrons for metallic bonding, like its heavier Group 13 element The underlying core under aluminium'svalence shell is that of the preceding noble gas, whereas those of its heavier congeners gallium, indium, thallium, and nihonium also include a filled d-subshell and in some cases a filled f-subshell. Hence, the inner electrons of aluminium shield the valence electrons almost completely, unlike those of aluminium'sheavier congeners. As such, aluminium is the most electropositive metal in its group, and its hydroxide is in fact more basic than that of gallium. Aluminium also bears minor similarities to the metalloid boron in the same group: AlX3 compounds are valence isoelectronic to BX3 compounds (they have the same valence electronic structure), and both behave as Lewis acids and readily form adducts. Additionally, one of the main motifs of boron chemistry is regular icosahedron Aluminium has a high chemical affinity to oxygen, which renders it suitable for use as a reducing agent in the thermite reaction. A fine powder of aluminium reacts explosively on contact with liquid oxygen; under normal conditions, however, aluminium forms a thin oxide layer (~5nm at room temperature) that protects the metal from further corrosion by | Wikipedia:Aluminium |
reducing agent in the thermite reaction. A fine powder of aluminium reacts explosively on contact with liquid oxygen; under normal conditions, however, aluminium forms a thin oxide layer (~5nm at room temperature) that protects the metal from further corrosion by oxygen, water, or dilute acid, a process termed passivation (chemistry) In hot concentrated hydrochloric acid, aluminium reacts with water with evolution of hydrogen, and in aqueous sodium hydroxide or potassium hydroxide at room temperature to form aluminates protective passivation under these conditions is negligible. Aqua regia also dissolves aluminium. such as common sodium chloride. The oxide layer on aluminium is also destroyed by contact with mercury (element) In aqueous solution, Al3+ exists as the hexaaqua cation [Al(H2O)6]3+, which has an approximate acid dissociation constant Aluminium hydroxide forms both salts and aluminates and dissolves in acid and alkali, as well as on fusion with acidic and basic oxides. This behavior of Al(OH)3 is termed amphoterism and is characteristic of weakly basic cations that form insoluble hydroxides and whose hydrated species can also donate their protons. One effect of this is that aluminium salts with weak acids are hydrolyzed in water to the aquated hydroxide and the corresponding nonmetal hydride: for example, aluminium sulfide yields hydrogen sulfide. However, some salts like aluminium carbonate exist in aqueous solution but are unstable as such; and only incomplete hydrolysis takes place for salts with strong acids, such as the halides, aluminium nitrate :2[Al(H2O)6]Cl3 Al2O3 + 6 HCl + 9 H2O All four Halide With heavier halides, the coordination numbers are lower. The other trihalides are Dimer (chemistry) Aluminium forms one stable oxide with the chemical formula Al2O3, commonly | Wikipedia:Aluminium |
called alumina. It can be found in nature in the mineral corundum, α-alumina; there is also a γ-alumina phase. Its crystalline form, corundum, is very hard (Mohs hardness 9), has a high melting point of , has very low volatility, is chemically inert, and a good electrical insulator, it is | Wikipedia:Aluminium |
r 150 intermetallics with other metals are known. Preparation involves heating fixed metals together in certain proportion, followed by gradual cooling and Annealing (metallurgy) There are few compounds with lower oxidation states. A few aluminium(I) compounds exist: | Wikipedia:Aluminium |
13 metals) and over 150 intermetallics with other metals are known. Preparation involves heating fixed metals together in certain proportion, followed by gradual cooling and Annealing (metallurgy) There are few compounds with lower oxidation states. A few aluminium(I) compounds exist: AlF, AlCl, AlBr, and AlI exist in the gaseous phase when the respective trihalide is heated with aluminium, and at cryogenic temperatures. A stable derivative of aluminium monoiodide is the cyclic adduct formed with triethylamine, Al4I4(NEt3)4. Al2O and Al2S also exist but are very unstable. Very simple aluminium(II) compounds are invoked or observed in the reactions of Al metal with oxidants. For example, aluminium monoxide, AlO, has been detected in the gas phase after explosion and in stellar absorption spectra. More thoroughly investigated are compounds of the formula R4Al2 which contain an Al–Al bond and where R is a large organic ligand. Organoaluminium compounds and related hydrides , a compound that features five-coordinate carbon. A variety of compounds of empirical formula AlR3 and AlR1.5Cl1.5 exist. The aluminium trialkyls and triaryls are reactive, volatile, and colorless liquids or low-melting solids. They catch fire spontaneously in air and react with water, thus necessitating precautions when handling them. They often form dimers, unlike their boron analogues, but this tendency diminishes for branched-chain alkyls (e.g. isopropyl The industrially most important aluminium hydride is lithium aluminium hydride (LiAlH4), which is used as a reducing agent in organic chemistry. It can be produced from lithium hydride and Aluminium chloride Natural occurrence Space Aluminium's per-particle abundance in the Solar System is 3.15 parts per million Because of its strong affinity for oxygen, aluminium is almost never found in the elemental | Wikipedia:Aluminium |
state; instead it is found in oxides or silicates. Feldspars, the most common group of minerals in the Earth'scrust, are aluminosilicates. Aluminium also occurs in the minerals beryl, cryolite, garnet, spinel, and turquoise. Impurities in Al2O3, such as chromium and iron, yield the gemstones ruby | Wikipedia:Aluminium |
in oxides or silicates. Feldspars, the most common group of minerals in the Earth'scrust, are aluminosilicates. Aluminium also occurs in the minerals beryl, cryolite, garnet, spinel, and turquoise. Impurities in Al2O3, such as chromium and iron, yield the gemstones ruby and sapphire, respectively. Native aluminium metal is extremely rare and can only be found as a minor phase in low oxygen fugacity environments, such as the interiors of certain volcanoes. Native aluminium has been reported in cold seeps in the northeastern continental slope of the South China Sea. It is possible that these deposits resulted from bacterial Redox Although aluminium is a common and widespread element, not all aluminium minerals are economically viable sources of the metal. Almost all metallic aluminium is produced from the ore bauxite (AlOx(OH)3–2x). Bauxite occurs as a weathering product of low iron and silica bedrock in tropical climatic conditions. In 2017, most bauxite was mined in Australia, China, Guinea, and India. History , the chemist who first thoroughly described metallic elemental aluminium The history of aluminium has been shaped by usage of alum. The first written record of alum, made by Ancient Greece The nature of alum remained unknown. Around 1530, Swiss physician Paracelsus suggested alum was a salt of an earth of alum. In 1595, German doctor and chemist Andreas Libavius experimentally confirmed this. In 1722, German chemist Friedrich Hoffmann announced his belief that the base of alum was a distinct earth. In 1754, German chemist Andreas Sigismund Marggraf synthesized alumina by boiling clay in sulfuric acid and subsequently adding potash. Attempts to produce aluminium date back to 1760. The first successful attempt, however, was completed in 1824 by Danish physicist and chemist Hans Christian Ørsted. He reacted anhydrous aluminium chloride with potassium amalgam (chemistry) in Piccadilly Circus, London, was made in 1893 and is one of the first statues cast in aluminium. As Wöhler'smethod could not yield great quantities of aluminium, the metal | Wikipedia:Aluminium |
Christian Ørsted. He reacted anhydrous aluminium chloride with potassium amalgam (chemistry) in Piccadilly Circus, London, was made in 1893 and is one of the first statues cast in aluminium. As Wöhler'smethod could not yield great quantities of aluminium, the metal remained rare; its cost exceeded that of gold. Even then, aluminium was still not of great purity and produced aluminium differed in properties by sample. Because of its electricity-conducting capacity, aluminium was used as the cap of the Washington Monument, completed in 1885, the tallest building in the world at the time. The non-corroding metal cap was intended to serve as a lightning rod peak. The first industrial large-scale production method was independently developed in 1886 by French engineer Paul Héroult and American engineer Charles Martin Hall; it is now known as the Hall–Héroult process. The Hall–Héroult process converts alumina into metal. Austrian chemist Carl Josef Bayer As large-scale production caused aluminium prices to drop, the metal became widely used in jewelry, eyeglass frames, optical instruments, tableware, and Aluminium foil From the early 20th century to 1980, the aluminium industry was characterized by Cartel Etymology The names aluminium and aluminum are derived from the word alumine, an obsolete term for alumina, the primary naturally occurring oxide of aluminium. Alumine was borrowed from French, which in turn derived it from alumen, the classical Latin name for alum, the mineral from which it was collected. The Latin word alumen stems from the Proto-Indo-European language Origins British chemist Humphry Davy, who performed a number of experiments aimed to isolate the metal, is credited as the person who named the element. The first name proposed for the metal to be isolated from alum was alumium, which Davy suggested in an 1808 article on his electrochemical research, published in Philosophical Transactions of the Royal Society. It appeared that the name was created from the English word alum and the Latin suffix -ium; | Wikipedia:Aluminium |
from alum was alumium, which Davy suggested in an 1808 article on his electrochemical research, published in Philosophical Transactions of the Royal Society. It appeared that the name was created from the English word alum and the Latin suffix -ium; but it was customary then to give elements names originating in Latin, so this name was not adopted universally. This name was criticized by contemporary chemists from France, Germany, and Sweden, who insisted the metal should be named for the oxide, alumina, from which it would be isolated. The English name alum does not come directly from Latin, whereas alumine/alumina comes from the Latin word alumen (upon declension, alumen changes to alumin-). One example was Essai sur la Nomenclature chimique (July 1811), written in French by a Swedish chemist, Jöns Jacob Berzelius, in which the name aluminium is given to the element that would be synthesized from alum. with his proposed system of one or two-letter chemical symbols, which are used up to the present day; sodium and potassium have the symbols Na and K, respectively, after their Latin names. (Another article in the same journal issue also refers to the metal whose oxide is the basis of sapphire, i.e. the same metal, as to aluminium.) A January 1811 summary of one of Davy'slectures at the Royal Society mentioned the name aluminium as a possibility. The next year, Davy published a chemistry textbook in which he used the spelling aluminum. Both spellings have coexisted since. Their usage is currently regional: aluminum dominates in the United States and Canada; aluminium is prevalent in the rest of the English-speaking world. Spelling In 1812, British scientist Thomas Young (scientist) Most scientists throughout the world used ' in the 19th century; In the 1830s, the ' spelling gained usage in the United States; by the 1860s, it had become the more common spelling there outside science. In 1892, Hall used the ' spelling in | Wikipedia:Aluminium |
world used ' in the 19th century; In the 1830s, the ' spelling gained usage in the United States; by the 1860s, it had become the more common spelling there outside science. In 1892, Hall used the ' spelling in his advertising handbill for his new electrolytic method of producing the metal, despite his constant use of the ' spelling in all the patents he filed between 1886 and 1903. It is unknown whether this spelling was introduced by mistake or intentionally, but Hall preferred aluminum since its introduction because it resembled platinum, the name of a prestigious metal. By 1890, both spellings had been common in the United States, the '' spelling being slightly more common; by 1895, the situation had reversed; by 1900, aluminum had become twice as common as aluminium; in the next decade, the '' spelling dominated American usage. In 1925, the American Chemical Society adopted this spelling. the most recent IUPAC nomenclature of inorganic chemistry 2005 Production and refinement The production of aluminium starts with the extraction of bauxite rock from the ground. The bauxite is processed and transformed using the Bayer process into alumina, which is then processed using the Hall–Héroult process, resulting in the final aluminium. Aluminium production is highly energy-consuming, and so the producers tend to locate smelters in places where electric power is both plentiful and inexpensive. Production of onekilogram of aluminium requires 7kilograms of oil energy equivalent, as compared to 1.5kilograms for steel and 2kilograms for plastic. As of 2024, the world'slargest producers of aluminium were China, Russia, India, Canada, and the United Arab Emirates, while China is by far the top producer of aluminium with a world share of over 55%. According to the International Resource Panel's Metal Stocks in Society report, the global per capita stock of aluminium in use in society (i.e. in cars, buildings, electronics, etc.) is . Much of this is in more-developed countries ( | Wikipedia:Aluminium |
over 55%. According to the International Resource Panel's Metal Stocks in Society report, the global per capita stock of aluminium in use in society (i.e. in cars, buildings, electronics, etc.) is . Much of this is in more-developed countries ( per capita) rather than less-developed countries ( per capita). Bayer process Bauxite is converted to alumina by the Bayer process. Bauxite is blended for uniform composition and then is ground fine. The resulting slurry is mixed with a hot solution of sodium hydroxide; the mixture is then treated in a digester vessel at a pressure well above atmospheric, dissolving the aluminium hydroxide in bauxite while converting impurities into relatively insoluble compounds: Hall–Héroult process billets of aluminium The conversion of alumina to aluminium is achieved by the Hall–Héroult process. In this energy-intensive process, a solution of alumina in a molten () mixture of cryolite (Na3AlF6) with calcium fluoride is electrolysis Electric power represents about 20 to 40% of the cost of producing aluminium, depending on the location of the smelter. Aluminium production consumes roughly 5% of electricity generated in the United States. Recycling involves melting the scrap, a process that requires only 5% of the energy used to produce aluminium from ore, though a significant part (up to 15% of the input material) is lost as dross (ash-like oxide). An aluminium stack melter produces significantly less dross, with values reported below 1%. White dross from primary aluminium production and from secondary recycling operations still contains useful quantities of aluminium that can be Aluminium dross recycling Applications (c. 1951) Metal The global production of aluminium in 2016 was 58.8million metric tons. It exceeded that of any other metal except iron (1,231million metric tons). Aluminium is almost always alloyed, which markedly improves its mechanical properties, especially when tempering (metallurgy) The major uses for aluminium are in: * Transportation (automobiles, aircraft, trucks, railway cars, marine vessels, bicycles, spacecraft, | Wikipedia:Aluminium |
other metal except iron (1,231million metric tons). Aluminium is almost always alloyed, which markedly improves its mechanical properties, especially when tempering (metallurgy) The major uses for aluminium are in: * Transportation (automobiles, aircraft, trucks, railway cars, marine vessels, bicycles, spacecraft, etc.). Aluminium is used because of its low density; * Packaging (aluminium can * Building and construction (windows, doors, Siding (construction) * Electricity-related uses (conductor alloys, motors, and generators, transformers, capacitors, etc.). Aluminium is used because it is relatively cheap, highly conductive, has adequate mechanical strength and low density, and resists corrosion; * A wide range of household items, from cooking utensils to furniture. Low density, good appearance, ease of fabrication, and durability are the key factors of aluminium usage; * Machinery and equipment (processing equipment, pipes, tools). Aluminium is used because of its corrosion resistance, non-pyrophoricity, and mechanical strength. Compounds The great majority (about 90%) of aluminium oxide is converted to metallic aluminium. alumina is widely used as an abrasive; being extraordinarily chemically inert, it is useful in highly reactive environments such as high pressure sodium lamps. Aluminium oxide is commonly used as a catalyst for industrial processes; Many industrial Catalysis Several sulfates of aluminium have industrial and commercial application. Aluminium sulfate (in its hydrate form) is produced on the annual scale of several millions of metric tons. About two-thirds is consumed in water treatment. * Aluminium phosphate is used in the manufacture of glass, ceramic, Wood pulp * Aluminium hydroxide is used as an antacid, and mordant; it is used also in water purification, the manufacture of glass and ceramics, and in the waterproofing of Textile * Lithium aluminium hydride is a powerful reducing agent used in organic chemistry. * Organoaluminium chemistry * Methylaluminoxane is a co-catalyst for Ziegler–Natta olefin polymerization to produce vinyl polymers such as polyethene. * Aqueous aluminium ions (such as aqueous aluminium sulfate) are used to treat against fish parasites such as Gyrodactylus salaris. * In | Wikipedia:Aluminium |
Organoaluminium chemistry * Methylaluminoxane is a co-catalyst for Ziegler–Natta olefin polymerization to produce vinyl polymers such as polyethene. * Aqueous aluminium ions (such as aqueous aluminium sulfate) are used to treat against fish parasites such as Gyrodactylus salaris. * In many vaccines, certain aluminium salts serve as an immune Immunologic adjuvant Biology Despite its widespread occurrence in the Earth'scrust, aluminium has no known function in biology. Aluminium sulfate has an Median lethal dose Toxicity Aluminium is classified as a non-carcinogen by the United States Department of Health and Human Services. likely due to exposure to polycyclic aromatic hydrocarbons. A review published in 1988 said that there was little evidence that normal exposure to aluminium presents a risk to healthy adult, and a 2014 multi-element toxicology review was unable to find deleterious effects of aluminium consumed in amounts not greater than 40mg/day per kg of body weight Effects Aluminium, although rarely, can cause vitamin D-resistant osteomalacia, erythropoietin-resistant microcytic anemia, and central nervous system alterations. People with kidney insufficiency are especially at a risk. Aluminium has been suspected of being a possible cause of Alzheimer'sdisease, but research into this for over 40 years has found, , no good evidence of causal effect. Aluminium increases estrogen-related gene expression in human breast cancer cells cultured in the laboratory. In very high doses, aluminium is associated with altered function of the blood–brain barrier. A small percentage of people have contact allergy Exposure to powdered aluminium or aluminium welding fumes can cause pulmonary fibrosis. Fine aluminium powder can ignite or explode, posing another workplace hazard. Exposure routes Food is the main source of aluminium. Drinking water contains more aluminium than solid food; Major sources of human oral exposure to aluminium include food (due to its use in food additives, food and beverage packaging, and cooking utensils), drinking water (due to its use in municipal water treatment), and aluminium-containing medications (particularly | Wikipedia:Aluminium |
solid food; Major sources of human oral exposure to aluminium include food (due to its use in food additives, food and beverage packaging, and cooking utensils), drinking water (due to its use in municipal water treatment), and aluminium-containing medications (particularly antacid/antiulcer and buffered aspirin formulations). Dietary exposure in Europeans averages to 0.2–1.5mg/kg/week but can be as high as 2.3mg/kg/week. Consumption of acidic foods or liquids with aluminium enhances aluminium absorption, and maltol has been shown to increase the accumulation of aluminium in nerve and bone tissues. Treatment In case of suspected sudden intake of a large amount of aluminium, the only treatment is deferoxamine mesylate which may be given to help eliminate aluminium from the body by chelation therapy. However, this should be applied with caution as this reduces not only aluminium body levels, but also those of other metals such as copper or iron. however, the main factor of presence of aluminium in salt and freshwater are the industrial processes that also release aluminium into air. which causes loss of Blood plasma Aluminium production possesses its own challenges to the environment on each step of the production process. The major challenge is the greenhouse gas emissions Biodegradation of metallic aluminium is extremely rare; most aluminium-corroding organisms do not directly attack or consume the aluminium, but instead produce corrosive wastes. The fungus Geotrichum candidum can consume the aluminium in compact discs. The bacterium Pseudomonas aeruginosa and the fungus Cladosporium resinae are commonly detected in aircraft fuel tanks that use kerosene-based fuels (not avgas), and laboratory cultures can degrade aluminium. See also * Aluminium granules * Aluminium joining * Aluminium–air battery * Aluminized steel, for corrosion resistance and other properties * Aluminized screen, for display devices * Aluminized cloth, to reflect heat * Aluminized mylar, to reflect heat * Panel edge staining * Quantum clock Notes References Bibliography * * * * * | Wikipedia:Aluminium |
properties * Aluminized screen, for display devices * Aluminized cloth, to reflect heat * Aluminized mylar, to reflect heat * Panel edge staining * Quantum clock Notes References Bibliography * * * * * * * * Further reading * Mimi Sheller, Aluminum Dream: The Making of Light Modernity. Cambridge, Mass.: Massachusetts Institute of Technology Press, 2014. External links * Aluminium at The Periodic Table of Videos (University of Nottingham) * Toxicological Profile for Aluminum (PDF) (September 2008) – 357-page report from the United States Department of Health and Human Services, Public Health Service, Agency for Toxic Substances and Disease Registry * Aluminum entry (last reviewed 30 October 2019) in the NIOSH Pocket Guide to Chemical Hazards published by the Centers for Disease Control and Prevention * Current and historical prices (1998present) for aluminum futures contract * Category:Aluminium Category:Chemical elements Category:Post-transition metals Category:Rocket fuels Category:Electrical conductors Category:Pyrotechnic fuels Category:Airship technology Category:Reducing agents Category:E-number additives Category:Native element minerals Category:Chemical elements with face-centered cubic structure | Wikipedia:Aluminium |
Acute disseminated encephalomyelitis (ADEM), or '''acute Demyelinating disease ADEM'ssymptoms resemble the symptoms of multiple sclerosis (MS), so the disease itself is sorted into the classification of the multiple sclerosis borderline diseases. However, ADEM has several features that distinguish it from MS. Unlike MS, ADEM occurs usually in children and is marked with rapid fever, although adolescents and adults can get the disease too. ADEM consists of a single flare-up whereas MS is marked with several flare-ups (or relapses), over a long period of time. Relapses following ADEM are reported in up to a quarter of patients, but the majority of these 'multiphasic' presentations following ADEM likely represent MS. ADEM is also distinguished by a loss of consciousness, coma and death, which is very rare in MS, except in severe cases. It affects about 8 per 1,000,000 people per year. Although it occurs in all ages, most reported cases are in children and Adolescence ADEM produces multiple Inflammation When a person has more than one demyelinating episode of ADEM, the disease is then called recurrent disseminated encephalomyelitis or multiphasic disseminated encephalomyelitis (MDEM). Also, a fulminant course in adults has been described. Signs and symptoms ADEM has an abrupt onset and a monophasic course. Symptoms usually begin 1–3 weeks after infection. Major symptoms include fever, headache, nausea and vomiting, confusion, Blindness ADEM in COVID-19 Neurological symptoms were the main presentation of COVID-19, which did not correlate with the severity of respiratory symptoms. The high incidence of ADEM with hemorrhage is striking. Brain inflammation is likely caused by an immune response to the disease rather than neurotropism. Cerebrospinal fluid analysis was not indicative of an infectious process, neurological impairment was not present in the acute phase of the infection, and neuroimaging | Wikipedia:Acute disseminated encephalomyelitis |
findings were not typical of classical toxic and metabolic disorders. The finding of bilateral periventricular relatively asymmetrical lesions allied with deep white matter involvement, that may also be present in cortical gray-white | Wikipedia:Acute disseminated encephalomyelitis |
agreement for a definition of multiple sclerosis. If MS were defined only by the separation in time and space of the demyelinating lesions as McDonald criteria The pathology of ADEM is very similar to that of MS with some differences. The pathological hallmark | Wikipedia:Acute disseminated encephalomyelitis |
hemorrhages, significant edema, and mass effect. Treatment No controlled clinical trials have been conducted on ADEM treatment, but aggressive treatment aimed at rapidly reducing inflammation of the | Wikipedia:Acute disseminated encephalomyelitis |
extensive T2-weighted and fluid-attenuated inversion recovery (FLAIR) white matter hyperintensities with areas of hemorrhages, significant edema, and mass effect. Treatment No controlled clinical trials have been conducted on ADEM treatment, but aggressive treatment aimed at rapidly reducing inflammation of the CNS is standard. The widely accepted first-line treatment is high doses of intravenous corticosteroids, mitoxantrone and cyclophosphamide. These are considered alternative therapies, used when corticosteroids cannot be used or fail to show an effect. There is some evidence to suggest that patients may respond to a combination of methylprednisolone and immunoglobulins if they fail to respond to either separately In a study of 16 children with ADEM, 10 recovered completely after high-dose methylprednisolone, one severe case that failed to respond to steroids recovered completely after IV Ig; the five most severe cases – with ADAM and severe peripheral neuropathy – were treated with combined high-dose methylprednisolone and immunoglobulin, two remained paraplegic, one had motor and cognitive handicaps, and two recovered. A study of IVIg treatment in adults with ADEM showed that IVIg seems more effective in treating sensory and motor disturbances, while steroids seem more effective in treating impairments of cognition, consciousness and rigor. Poorer outcomes are associated with unresponsiveness to steroid therapy, unusually severe neurological symptoms, or sudden onset. Children tend to have more favorable outcomes than adults, and cases presenting without fevers tend to have poorer outcomes. The latter effect may be due to either protective effects of fever, or that diagnosis and treatment is sought more rapidly when fever is present. ADEM can progress to MS. It will be considered MS if some lesions appear in different times and brain areas Motor deficits Residual motor deficits are estimated to remain in about 8 to 30% of cases, the range in severity from mild clumsiness to ataxia and hemiparesis. Research suggests that similar effects are seen after ADEM, but that the deficits are less severe than those seen in MS. | Wikipedia:Acute disseminated encephalomyelitis |
remain in about 8 to 30% of cases, the range in severity from mild clumsiness to ataxia and hemiparesis. Research suggests that similar effects are seen after ADEM, but that the deficits are less severe than those seen in MS. A study of six children with ADEM (mean age at presentation 7.7 years) were tested for a range of neurocognitive tests after an average of 3.5 years of recovery. All six children performed in the normal range on most tests, including Wechsler Adult Intelligence Scale#Verbal Subtests Another study compared nineteen children with a history of ADEM, of which 10 were five years of age or younger at the time (average age 3.8 years old, tested an average of 3.9 years later) and nine were older (mean age 7.7y at time of ADEM, tested an average of 2.2 years later) to nineteen matched controls. Scores on IQ tests and educational achievement were lower for the young onset ADEM group (average IQ 90) compared to the late onset (average IQ 100) and control groups (average IQ 106), while the late onset ADEM children scored lower on verbal processing speed. Again, all groups means were within one standard deviation of the controls, meaning that while effects were statistically reliable, the children were as a whole, still within the normal range. There were also more behavioural problems in the early onset group, although there is some suggestion that this may be due, at least in part, to the stress of hospitalization at a young age. Research The relationship between ADEM and anti-MOG associated encephalomyelitis is currently under research. A new entity called MOGDEM has been proposed. About animal models, the main animal model for MS, experimental autoimmune encephalomyelitis (EAE) is also an animal model for ADEM. Being an acute monophasic illness, EAE is far more similar to ADEM than MS. See also * Optic neuritis * Transverse myelitis * meningitis-retention syndrome * Victoria Arlen | Wikipedia:Acute disseminated encephalomyelitis |
autoimmune encephalomyelitis (EAE) is also an animal model for ADEM. Being an acute monophasic illness, EAE is far more similar to ADEM than MS. See also * Optic neuritis * Transverse myelitis * meningitis-retention syndrome * Victoria Arlen References External links * * * Acute Disseminated Encephalomyelitis, Siegel Rare Neuroimmune Association * Information for parents about Acute disseminated encephalomyelitis, Great Ormond Street Hospital Category:Multiple sclerosis Category:Autoimmune diseases Category:Central nervous system disorders Category:Enterovirus-associated diseases Category:Measles Category:Rare diseases | Wikipedia:Acute disseminated encephalomyelitis |
) Augusta Ada King, Countess of Lovelace (née Byron; 10 December 1815 – 27 November 1852), also known as Ada Lovelace, was an English mathematician and writer chiefly known for her work on Charles Babbage'sproposed mechanical general-purpose computer, the Analytical Engine. She was the first to recognise that the machine had applications beyond pure calculation. Lovelace was the only legitimate child of poet Lord Byron and reformer Anne Isabella Milbanke. All her half-siblings, Lord Byron#Children Though Babbage's Analytical Engine was never constructed and exercised no influence on the later invention of electronic computers, it has been recognised in retrospect as a Turing completeness Between 1842 and 1843, Lovelace translated wikisource:Scientific Memoirs/3/Sketch of the Analytical Engine invented by Charles Babbage, Esq. She also developed a vision of the capability of computers to go beyond mere calculating or number-crunching, while many others, including Babbage himself, focused only on those capabilities. Lovelace was the first to point out the possibility of encoding information besides mere arithmetical figures, such as music, and manipulating it with such a machine. Her mindset of "poetical science" led her to ask questions about the Analytical Engine (as shown in her notes), examining how individuals and society relate to technology as a collaborative tool. The programming language Ada (programming language) Biography Childhood Lord Byron expected his child to be a "glorious boy" and was disappointed when Lady Byron gave birth to a girl. The child was named after Byron'shalf-sister, Augusta Leigh, and was called "Ada" by Byron himself. On 16 January 1816, at Lord Byron'scommand, Lady Byron left for her parents' home at Kirkby Mallory, taking their five-week-old daughter with her. Although English law at the time granted full custody of children to the father in cases of separation, Lord Byron made no attempt to claim his parental rights, but did request that his sister keep him informed of Ada'swelfare. On 21 April, Lord Byron signed the deed of separation, | Wikipedia:Ada Lovelace |
of children to the father in cases of separation, Lord Byron made no attempt to claim his parental rights, but did request that his sister keep him informed of Ada'swelfare. On 21 April, Lord Byron signed the deed of separation, although very reluctantly, and left England for good a few days later. Aside from an acrimonious separation, Lady Byron continued throughout her life to make allegations about her husband'simmoral behaviour. This set of events made Lovelace infamous in Victorian society. Ada did not have a relationship with her father. He died in 1824 when she was eight years old. Her mother was the only significant parental figure in her life. Lovelace was not shown the family portrait of her father until her 20th birthday. , 1822, Somerville College, Oxford. Lovelace did not have a close relationship with her mother. She was often left in the care of her maternal grandmother Judith, Hon. Lady Milbanke, who doted on her. However, because of societal attitudes of the time which favoured the husband in any separation, with the welfare of any child acting as mitigation Lady Byron had to present herself as a loving mother to the rest of society. This included writing anxious letters to Lady Milbanke about her daughter'swelfare, with a cover note saying to retain the letters in case she had to use them to show maternal concern. In one letter to Lady Milbanke, she referred to her daughter as "it": "I talk to it for your satisfaction, not my own, and shall be very glad when you have it under your own." Lady Byron had her teenage daughter watched by close friends for any sign of moral deviation. Lovelace dubbed these observers the "Furies" and later complained they exaggerated and invented stories about her. Lovelace was often ill, beginning in early childhood. At the age of eight, she experienced headaches that obscured her vision. In June 1829, she was paralyzed after a bout | Wikipedia:Ada Lovelace |
"Furies" and later complained they exaggerated and invented stories about her. Lovelace was often ill, beginning in early childhood. At the age of eight, she experienced headaches that obscured her vision. In June 1829, she was paralyzed after a bout of measles. She was subjected to continuous bed rest for nearly a year, something which may have extended her period of disability. By 1831, she was able to walk with crutches. Despite the illnesses, she developed her mathematical and technological skills. Ada Byron had an affair with a tutor in early 1833. She tried to elope with him after she was caught, but the tutor'srelatives recognised her and contacted her mother. Lady Byron and her friends covered the incident up to prevent a public scandal. Lovelace never met her younger half-sister, Allegra Byron Adult years . Lovelace became close friends with her tutor Mary Somerville, who introduced her to Charles Babbage in 1833. She had a strong respect and affection for Somerville, and they corresponded for many years. Other acquaintances included the scientists Andrew Crosse, David Brewster On 8 July 1835, she married William King, 1st Earl of Lovelace They had three children: Byron King-Noel, Viscount Ockham In 1841, Lovelace and Elizabeth Medora Leigh Education ). From 1832, when she was seventeen, her mathematical abilities began to emerge, and her interest in mathematics dominated the majority of her adult life. Her mother'sobsession with rooting out any of the insanity of which she accused Byron was one of the reasons that Ada was taught mathematics from an early age. She was privately educated in mathematics and science by William Frend (social reformer) Lovelace often questioned basic assumptions through integrating poetry and science. Whilst studying differential calculus, she wrote to De Morgan: I may remark that the curious transformations many formulae can undergo, the unsuspected and to a beginner apparently impossible identity of forms exceedingly dissimilar at first sight, is I think one of | Wikipedia:Ada Lovelace |
studying differential calculus, she wrote to De Morgan: I may remark that the curious transformations many formulae can undergo, the unsuspected and to a beginner apparently impossible identity of forms exceedingly dissimilar at first sight, is I think one of the chief difficulties in the early part of mathematical studies. I am often reminded of certain sprites and fairies one reads of, who are at one'selbows in one shape now, and the next minute in a form most dissimilar. Lovelace believed that intuition and imagination were critical to effectively applying mathematical and scientific concepts. She valued metaphysics as much as mathematics, viewing both as tools for exploring "the unseen worlds around us". Death (1852). Although in great pain at the time, she agreed to sit for the painting as her father, Lord Byron, had been painted by Phillips' father, Thomas Phillips. Lovelace died at the age of 36 on 27 November 1852 from cervical cancer (which contemporary accounts called uterine cancer, since a distinction between the two was not made at time). The illness lasted several months, in which time Annabella took command over whom Ada saw, and excluded all of her friends and confidants. Under her mother'sinfluence, Ada had a religious transformation and was coaxed into repenting of her previous conduct and making Annabella her executor. She lost contact with her husband after confessing something to him on 30 August which caused him to abandon her bedside. It is not known what she told him. She was buried, at her request, next to her father at the Church of St. Mary Magdalene, Hucknall Work Throughout her life, Lovelace was strongly interested in scientific developments and fads of the day, including phrenology and mesmerism. After her work with Babbage, Lovelace continued to work on other projects. In 1844, she commented to a friend Woronzow Greig about her desire to create a mathematical model for how the brain gives rise to thoughts and | Wikipedia:Ada Lovelace |
and mesmerism. After her work with Babbage, Lovelace continued to work on other projects. In 1844, she commented to a friend Woronzow Greig about her desire to create a mathematical model for how the brain gives rise to thoughts and nerves to feelings ("a calculus of the nervous system"). She never achieved this, however. In part, her interest in the brain came from a long-running preoccupation, inherited from her mother, about her "potential" madness. As part of her research into this project, she visited the electrical engineer Andrew Crosse in 1844 to learn how to carry out electrical experiments. In the same year, she wrote a review of a paper by Baron Karl von Reichenbach, Researches on Magnetism, but this was not published and does not appear to have progressed past the first draft. In 1851, the year before her cancer struck, she wrote to her mother mentioning "certain productions" she was working on regarding the relation of maths and music. '' by the British painter Margaret Sarah Carpenter (1836). Lovelace first met Charles Babbage in June 1833, through their mutual friend Mary Somerville. Later that month, Babbage invited Lovelace to see the prototype for his difference engine. She became fascinated with the machine and used her relationship with Somerville to visit Babbage as often as she could. Babbage was impressed by Lovelace'sintellect and analytic skills. He called her "The Enchantress of Number". In 1843, he wrote to her: ", the first published computer algorithm/ In 1840, Babbage was invited to give a seminar at the University of Turin about his Analytical Engine. Luigi Menabrea, a young Italian engineer and the future Prime Minister of Italy, transcribed Babbage'slecture into French, and this transcript was subsequently published in the Bibliothèque universelle de Genève in October | Wikipedia:Ada Lovelace |
1842. Babbage'sfriend Charles Wheatstone commissioned Lovelace to translate Menabrea'spaper into English. During a nine-month period in 1842–43, Lovelace translated Menabrea'sarticle. She then augmented the paper with notes, which | Wikipedia:Ada Lovelace |
transcript was subsequently published in the Bibliothèque universelle de Genève in October 1842. Babbage'sfriend Charles Wheatstone commissioned Lovelace to translate Menabrea'spaper into English. During a nine-month period in 1842–43, Lovelace translated Menabrea'sarticle. She then augmented the paper with notes, which were added to the translation. The translation and notes were then published in the September 1843 edition of Taylor's Scientific Memoirs under the initialism AAL. Explaining the Analytical Engine'sfunction was a difficult task; many other scientists did not grasp the concept and the British establishment had shown little interest in it. Lovelace'snotes even had to explain how the Analytical Engine differed from the original Difference Engine. Her work was well received at the time; the scientist Michael Faraday described himself as a supporter of her writing. Lovelace and Babbage had a minor falling out when the papers were published, when he tried to leave his own statement (criticising the government'streatment of his Engine) as an unsigned preface, which could have been mistakenly interpreted as a joint declaration. When Richard Taylor (editor) First published computer program The notes, around three times longer than the article itself, are important in the early history of computers, especially since the Note G In 1953, more than a century after her death, Ada Lovelace'snotes on Babbage's Analytical Engine were republished as an appendix to B. V. Bowden's Faster than Thought: A Symposium on Digital Computing Machines. The engine has now been recognised as an early model for a computer and her notes as a description of a computer and software. Controversy over contribution Based on this work, Lovelace is often called the first computer programmer and her method has been called the world'sfirst computer program. Eugene Eric Kim and Betty Alexandra Toole consider it "incorrect" to regard Lovelace as the first computer programmer. Babbage claims credit in his autobiography for the algorithm in Note G, and regardless of the extent of Lovelace'scontribution to it, she was not | Wikipedia:Ada Lovelace |
Kim and Betty Alexandra Toole consider it "incorrect" to regard Lovelace as the first computer programmer. Babbage claims credit in his autobiography for the algorithm in Note G, and regardless of the extent of Lovelace'scontribution to it, she was not the very first person to write a program for the Analytical Engine, as Babbage had written the initial programs for it, although the majority were never published. Bromley notes several dozen sample programs prepared by Babbage between 1837 and 1840, all substantially predating Lovelace'snotes. Dorothy K. Stein regards Lovelace'snotes as "more a reflection of the mathematical uncertainty of the author, the political purposes of the inventor, and, above all, of the social and cultural context in which it was written, than a blueprint for a scientific development". Allan Bromley (historian) p. 89. Bruce Collier wrote that Lovelace "made a considerable contribution to publicizing the Analytical Engine, but there is no evidence that she advanced the design or theory of it in any way". Doron Swade has said that Ada only published the first computer program instead of actually writing it, but agrees that she was the only person to see the potential of the analytical engine as a machine capable of expressing entities other than quantities. In his book, Idea Makers, Stephen Wolfram defends Lovelace'scontributions. While acknowledging that Babbage wrote several unpublished algorithms for the Analytical Engine prior to Lovelace'snotes, Wolfram argues that "there'snothing as sophisticated or as clean as Ada'scomputation of the Bernoulli numbers. Babbage certainly helped and commented on Ada'swork, but she was definitely the driver of it." Wolfram then suggests that Lovelace'smain achievement was to distill from Babbage'scorrespondence "a clear exposition of the abstract operation of the machine something which Babbage never did". Insight into potential of computing devices In | Wikipedia:Ada Lovelace |
her notes, Ada Lovelace emphasised the difference between the Analytical Engine and previous calculating machines, particularly its ability to be programmed to solve problems of any complexity. She realised the potential of | Wikipedia:Ada Lovelace |
did". Insight into potential of computing devices In her notes, Ada Lovelace emphasised the difference between the Analytical Engine and previous calculating machines, particularly its ability to be programmed to solve problems of any complexity. She realised the potential of the device extended far beyond mere number crunching. In her notes, she wrote: This analysis was an important development from previous ideas about the capabilities of computing devices and anticipated the implications of modern computing one hundred years before they were realised. Walter Isaacson ascribes Ada'sinsight regarding the application of computing to any process based on logical symbols to an observation about textiles: "When she saw some Jacquard machine According to the historian of computing and Babbage specialist Doron Swade: Ada saw something that Babbage in some sense failed to see. In Babbage'sworld his engines were bound by number...What Lovelace saw...was that number could represent entities other than quantity. So once you had a machine for manipulating numbers, if those numbers represented other things, letters, musical notes, then the machine could manipulate symbols of which number was one instance, according to rules. It is this fundamental transition from a machine which is a number cruncher to a machine for manipulating symbols according to rules that is the fundamental transition from calculation to computation to general-purpose computation and looking back from the present high ground of modern computing, if we are looking and sifting history for that transition, then that transition was made explicitly by Ada in that 1843 paper. Note G also contains Lovelace'sdismissal of artificial intelligence. She wrote that "The Analytical Engine has no pretensions whatever to originate anything. It can do whatever we know how to order it to perform. It can follow analysis; but it has no power of anticipating any analytical relations or truths." This objection has been the subject of much debate and rebuttal, for example by Alan Turing in his paper "Computing Machinery and Intelligence". Most modern | Wikipedia:Ada Lovelace |
can follow analysis; but it has no power of anticipating any analytical relations or truths." This objection has been the subject of much debate and rebuttal, for example by Alan Turing in his paper "Computing Machinery and Intelligence". Most modern computer scientists argue that this view is outdated and that computer software can develop in ways that cannot necessarily be anticipated by programmers. Distinction between mechanism and logical structure Lovelace recognized the difference between the details of the computing mechanism, as covered in an 1834 article on the Difference Engine, and the logical structure of the Analytical Engine, on which the article she was reviewing dwelt. She noted that different specialists might be required in each area. The [1834 article] chiefly treats it under its mechanical aspect, entering but slightly into the mathematical principles of which that engine is the representative, but giving, in considerable length, many details of the mechanism and contrivances by means of which it tabulates the various orders of differences. M. Menabrea, on the contrary, exclusively developes the analytical view; taking it for granted that mechanism is able to perform certain processes, but without attempting to explain how; and devoting his whole attention to explanations and illustrations of the manner in which analytical laws can be so arranged and combined as to bring every branch of that vast subject within the grasp of the assumed powers of mechanism. It is obvious that, in the invention of a calculating engine, these two branches of the subject are equally essential fields of investigation... They are indissolubly connected, though so different in their intrinsic nature, that perhaps the same mind might not be likely to prove equally profound or successful in both. The reference manual for the language was approved on 10 December 1980 and the United States Military Standard In 1981, the Association for Women in Computing inaugurated its Ada Lovelace Award. , the British Computer Society (BCS) has awarded | Wikipedia:Ada Lovelace |
both. The reference manual for the language was approved on 10 December 1980 and the United States Military Standard In 1981, the Association for Women in Computing inaugurated its Ada Lovelace Award. , the British Computer Society (BCS) has awarded the Lovelace Medal, and in 2008 initiated an annual competition for women students. Ada College is a further-education college in Tottenham Hale, London, focused on digital skills. Ada Lovelace Day is an annual event celebrated on the second Tuesday of October, which began in 2009. Its goal is to "...raise the profile of women in science, technology, engineering, and maths," and to "create new role models for girls and women" in these fields. A specialist technical college, for pupils aged 16–19, in England is named "Ada, the National College for Digital Skills", it has campuses in Whitechapel, Tottenham Hale and Manchester. The building of the department of Engineering Mathematics at the University of Bristol is called the Ada Lovelace Building. The Engineering in Computer Science and Telecommunications College building in Zaragoza University is called the Ada Byron Building. The computer centre in the village of Porlock, near where Lovelace lived, is named after her. Ada Lovelace House is a council-owned building in Kirkby-in-Ashfield, Nottinghamshire, near where Lovelace spent her infancy. In 2012, a Google Doodle and blog post honoured her on her birthday. In 2013, Ada Developers Academy was founded and named after her. Its mission is to diversify tech by providing women and gender-diverse people the skills, experience, and community support to become professional software developers to change the face of tech. On 17 September 2013, the BBC Radio 4 biography programme Great Lives devoted an episode to Ada Lovelace; she was sponsored by TV presenter Konnie Huq. As of November 2015, all new British passports have included an illustration of Lovelace and Babbage. In 2017, a Google Doodle honoured her with other women on International Women's Day. On 2 February | Wikipedia:Ada Lovelace |
was sponsored by TV presenter Konnie Huq. As of November 2015, all new British passports have included an illustration of Lovelace and Babbage. In 2017, a Google Doodle honoured her with other women on International Women's Day. On 2 February 2018, Satellogic, a high-resolution Earth observation imaging and analytics company, launched a ÑuSat type Small satellite On 27 July 2018, Ron Wyden In March 2022, a statue of Ada Lovelace was installed at the site of the former Ergon House in the City of Westminster, London, honoring its scientific history. The redevelopment was part of a complex with Imperial Chemical House. The statue was sculpted by Etienne and Mary Millner and based on the portrait by Margaret Sarah Carpenter. The sculpture was unveiled on International Women's Day, 2022. It stands on the 7th floor of Millbank Quarter overlooking the junction of Dean Bradley Street and Horseferry Road. In September 2022, Nvidia announced the Ada Lovelace (microarchitecture) Bicentenary (2015) The Anniversary * The Ada Lovelace Bicentenary Lectures on Computability, Israel Institute for Advanced Studies, 20 December 2015 – 31 January 2016. * Ada Lovelace Symposium, University of Oxford, 13–14 October 2015. *Ada.Ada.Ada, a one-woman show about the life and work of Ada Lovelace (using an LED dress), premiered at Edinburgh International Science Festival on 11 April 2015, and continued to touring internationally to promote diversity on STEM at technology conferences, businesses, government and educational organisations. Special exhibitions were displayed by the Science Museum, London In popular culture portrait created for the Ada Initiative, which supported open technology and women. Novels and plays Lovelace is portrayed in Romulus Linney (playwright) In the 1990 steampunk novel The Difference Engine by William Gibson and Bruce Sterling, Lovelace delivers a lecture on the "punched cards" programme which proves Gödel'sincompleteness theorems decades before their actual discovery. Lovelace and Mary Shelley as teenagers are the central characters in Jordan Stratford'ssteampunk series, The Wollstonecraft Detective Agency. Lovelace features in John | Wikipedia:Ada Lovelace |
Lovelace delivers a lecture on the "punched cards" programme which proves Gödel'sincompleteness theorems decades before their actual discovery. Lovelace and Mary Shelley as teenagers are the central characters in Jordan Stratford'ssteampunk series, The Wollstonecraft Detective Agency. Lovelace features in John Crowley (author) The 2015 play Ada and the Engine by Lauren Gunderson portrays Lovelace and Charles Babbage in unrequited love, and it imagines a post-death meeting between Lovelace and her father. Lovelace and Babbage are also the main characters in Sydney Padua'swebcomic and graphic novel The Thrilling Adventures of Lovelace and Babbage. The comic features extensive footnotes on the history of Ada Lovelace, and many lines of dialogue are drawn from actual correspondence. Film and television In the 1997 film Conceiving Ada, a computer scientist obsessed with Ada finds a way of communicating with her in the past by means of "undying information waves". Lovelace, identified as Ada Augusta Byron, is portrayed by Lily Lesser in the second series of The Frankenstein Chronicles aired on ITV in 2017. She is employed as an "analyst" to provide the workings of a life-sized humanoid automaton. The brass workings of the machine are reminiscent of Babbage'sanalytical engine. Her employment is described as keeping her occupied until she returns to her studies in advanced mathematics. Lovelace and Babbage appear as characters in the Victoria (British TV series) "Lovelace" is the name of the operating system designed by the character Cameron Howe in Halt and Catch Fire (TV series) Lovelace features as a character in "Spyfall (Doctor Who) * The Lovelace Lectures at Durham University. * The Ada Lovelace Award awarded by the Association for Women in Computing * The Ada Initiative supporting open technology and women is named after her. * Ada Lovelace Building, the engineering mathematics building at the University of Bristol. * Ada Lovelace Building, in Exeter Science Park. * Ada Byron Building, in the Department of Computer Science and Systems Engineering at the | Wikipedia:Ada Lovelace |
is named after her. * Ada Lovelace Building, the engineering mathematics building at the University of Bristol. * Ada Lovelace Building, in Exeter Science Park. * Ada Byron Building, in the Department of Computer Science and Systems Engineering at the University of Zaragoza. * Ada Byron Research Centre in University of Malaga, Andalucía. * Ada Lovelace Institute, a think tank dedicated to ensuring data and AI work for people and society. * Ada Lovelace Centre for Digital Scholarship, Oxford * Ada Lovelace Center for Digital Humanities at the FU Berlin. * ADA Lovelace Centre for Analytics, Data, Applications at Fraunhofer IIS originally called the ADA Lovelace Centre for Artificial Intelligence''. * Ada Lovelace Excellence Scholarship at the University of Southampton. * Adafruit Industries * Ada Lovelace Centre, part of the Science and Technology Facilities Council, a UK government agency that carries out research in science and engineering. * The Cardano (blockchain platform) * Ada, an artwork incorporating artificial intelligence house at Microsoft's Building 99. * In 2021, the code name of Nvidia's Graphics processing unit * Ada Byron University Programming Contest at the Polytechnic University of Valencia. Other * A green plaque is to be found on Fordhook Avenue on the corner of 5 Station Parade, Uxbridge Road, Ealing. * Blue plaques are at Mallory Park and St James's Square. * Ada Lovelace C of E High School in Greenford, specialising in music, digital technologies and languages. * Ada Lovelace House, council offices in Nottinghamshire, later proposed to be let to small business. * Ada Byron King Building at Nottingham Trent University * Ada Lovelace Suite at Seaham Hall. * The Lovelace Memorial is a Grade II Listed monument in Kirkby Mallory. * A clone of Ada Lovelace appears in the 2023 video game Starfield (video game) * Ada Lovelace is a playable leader in Sid Meier's Civilization VII. Publications * Lovelace, Ada King. Ada, the Enchantress of Numbers: A Selection from | Wikipedia:Ada Lovelace |
* A clone of Ada Lovelace appears in the 2023 video game Starfield (video game) * Ada Lovelace is a playable leader in Sid Meier's Civilization VII. Publications * Lovelace, Ada King. Ada, the Enchantress of Numbers: A Selection from the Letters of Lord Byron's Daughter and her Description of the First Computer. Mill Valley, CA: Strawberry Press, 1992. . * **Also available on Wikisource: wikisource:Scientific Memoirs/3/Sketch of the Analytical Engine invented by Charles Babbage, Esq. Publication history Six copies of the 1843 first edition of Sketch of the Analytical Engine'' with Ada Lovelace's "Notes" On 20 July 2018, the sixth copy was sold at auction to an anonymous buyer for £95,000. A digital facsimile of one of the copies in the Harvard University Library is available online. In December 2016, a letter written by Ada Lovelace was forfeited by Martin Shkreli to the New York State Department of Taxation and Finance for unpaid taxes owed by Shkreli. See also * Ai-Da – humanoid robot, completed in 2019 * Code: Debugging the Gender Gap * List of pioneers in computer science * Timeline of women in science * Women in computing * Women in STEM fields Explanatory notes References Citations General and cited sources * . * . * . * . * . * . * * * . * With notes upon the memoir by the translator. * Miller, Clair Cain. "Ada Lovelace, 1815–1852," New York Times, 8 March 2018. * . * . * . * . * . * * . * . Further reading * Jennifer Chiaverini, 2017, Enchantress of Numbers, E. P. Dutton * Christopher Hollings, Ursula Martin, and Adrian Rice, 2018, Ada Lovelace: The Making of a Computer | Wikipedia:Ada Lovelace |
Scientist, Bodleian Library, 114 pp. * Miranda Seymour, 2018, ''In Byron's Wake: The Turbulent Lives of Byron's Wife and Daughter: Annabella Milbanke and Ada Lovelace'', Pegasus, 547 pp. * Jenny Uglow (22 November | Wikipedia:Ada Lovelace |
Ada Lovelace: The Making of a Computer Scientist, Bodleian Library, 114 pp. * Miranda Seymour, 2018, ''In Byron's Wake: The Turbulent Lives of Byron's Wife and Daughter: Annabella Milbanke and Ada Lovelace'', Pegasus, 547 pp. * Jenny Uglow (22 November 2018), "Stepping Out of Byron's Shadow", The New York Review of Books, vol. LXV, no. 18, pp.30–32. External links * "Ada's Army gets set to rewrite history at Inspirefest 2018" by Luke Maxwell, 4 August 2018 * * "Untangling the Tale of Ada Lovelace" by Stephen Wolfram, December 2015 * * * * * * * * * * * * Category:Ada Lovelace Category:1815 births Category:1852 deaths Category:19th-century British women mathematicians Category:19th-century English writers Category:19th-century English mathematicians Category:19th-century English women writers Category:19th-century British inventors Category:British women inventors Category:19th-century English nobility Category:Ada (programming language) Category:Amateur mathematicians Category:British countesses Category:British women computer scientists Category:Burials in Nottinghamshire Category:Byron family Category:Computer designers Category:Daughters of barons Category:Deaths from cancer in England Category:Deaths from uterine cancer in the United Kingdom Category:English computer programmers Category:English people of Scottish descent Category:English women poets Category:Godwin family Category:Family of Lord Byron Category:Mathematicians from London Category:Women of the Victorian era Category:Burials at the Church of St Mary Magdalene, Hucknall Category:19th-century women inventors | Wikipedia:Ada Lovelace |
of the absolute value function for real numbers In mathematics, the absolute value or modulus of a real number x, is the non-negative value without regard to its sign (mathematics) Generalisations of the absolute value for real numbers occur in a wide variety of mathematical settings. For example, an absolute value is also defined for the complex numbers, the quaternions, ordered rings, Field (mathematics) Terminology and notation In 1806, Jean-Robert Argand introduced the term module, meaning unit of measure in French, specifically for the complex absolute value, and it was borrowed into English in 1866 as the Latin equivalent modulus. and 1857 in English. The notation , with a vertical bar on each side, was introduced by Karl Weierstrass in 1841. Other names for absolute value include numerical value and in spreadsheets, programming languages, and computational software packages, the absolute value of x is generally represented by abs(x), or a similar expression, as it has been since the earliest days of high-level programming languages. The vertical bar notation also appears in a number of other mathematical contexts: for example, when applied to a set, it denotes its cardinality; when applied to a Matrix (math) Definition and properties Real numbers For any the absolute value or modulus is denoted , with a vertical bar on each side of the quantity, and is defined as cases x, & if x 0 \\ -x, & if x The absolute value is thus always either a positive number or 0 From an analytic geometry point of view, the absolute value of a real number is that number'sdistance from zero along the real number line, and more generally the absolute value of the difference of two real numbers (their absolute difference) is the distance between them. The notion of an abstract distance function in mathematics can be seen to be a generalisation of the absolute value of the difference (see #Distance Since the radical symbol This is | Wikipedia:Absolute value |
numbers (their absolute difference) is the distance between them. The notion of an abstract distance function in mathematics can be seen to be a generalisation of the absolute value of the difference (see #Distance Since the radical symbol This is equivalent to the definition above, and may be used as an alternative definition of the absolute value of real numbers. The absolute value has the following four fundamental properties (a, b are real numbers), that are used for generalization of this notion to other domains: Non-negativity, positive definiteness, and multiplicativity are readily apparent from the definition. To see that subadditivity holds, first note that Some additional useful properties are given below. These are either immediate consequences of the definition or implied by the four fundamental properties above. Two other useful properties concerning inequalities are: These relations may be used to solve inequalities involving absolute values. For example: The absolute value, as "distance from zero", is used to define the absolute difference between arbitrary real numbers, the standard Metric (mathematics) Complex numbers Since the complex numbers are not Totally ordered set z x + iy, where x and y are real numbers, the absolute value or modulus is and is defined by the Pythagorean addition of x and y, where Re(z) x and Im(z) ydenote the real and imaginary parts respectively. When the is zero, this coincides with the definition of the absolute value of the When a complex number z is expressed in its Complex number#Polar form Since the product of any complex number z and its with the same absolute value, is always the non-negative real number the absolute value of a complex number z is the square root nowrap This generalizes the alternative definition for reals: nowrap The complex absolute value shares the four fundamental properties given above for the real absolute value. The identity Absolute value function of the absolute value function for real numbers of absolute value with a | Wikipedia:Absolute value |
the alternative definition for reals: nowrap The complex absolute value shares the four fundamental properties given above for the real absolute value. The identity Absolute value function of the absolute value function for real numbers of absolute value with a cubic function in different orders The real absolute value function is continuous function For both real and complex numbers the absolute value function is idempotent (meaning that the absolute value of any absolute value is itself). Relationship to the sign function The absolute value function of a real number returns its value irrespective of its sign, whereas the sign function : or : and for , :(x) x x. Relationship to the max and min functions Let s,t, then the following relationship to the minimum and maximum functions hold: : and : The formulas can be derived by considering each case s>t and t>sseparately. From the last formula one can derive also Derivative The real absolute value function has a derivative for every , but is not differentiable at . Its derivative for is given by the step function: :d The real absolute value function is an example of a continuous function that achieves a Maximum and minimum The subderivative The complex number : Generalizations Ordered rings The definition of absolute value given for real numbers above can be extended to any ordered ring. That is, if is an element of an ordered ringR, then the absolute value of, denoted by , is defined to be: : arrayrl a, & if a 0 \\ -a, & if a where is the additive inverse of, 0 is the additive identity, and v(a) 0 Where 0 denotes the additive identity of. It follows from positive-definiteness and multiplicativity that , where 1 denotes the multiplicative identity of. The real and complex absolute values defined above are examples of absolute values for an arbitrary field. If is an absolute value on, then the function | Wikipedia:Absolute value |
follows from positive-definiteness and multiplicativity that , where 1 denotes the multiplicative identity of. The real and complex absolute values defined above are examples of absolute values for an arbitrary field. If is an absolute value on, then the function on , defined by , is a metric and the following are equivalent: * satisfies the ultrametric inequality d(x, y) (d(x,z),d(y,z)) for all , , in. * \ v( _ k 1^n 1) : n \ is bounded set * v(^n 1) 1\ for every n . * v(a) 1 v(1+a) 1\ for all a F. * v(a + b) \v(a), v(b)\\ for all a, b F. An absolute value which satisfies any (hence all) of the above conditions is said to be non-Archimedean, otherwise it is said to be Archimedean field Vector spaces Again the fundamental properties of the absolute value for real numbers can be used, with a slight modification, to generalise the notion to an arbitrary vector space. A real-valued function on a vector space over a field, represented as , is called an absolute value, but more usually a Norm (mathematics) For all in, and , in, : The norm of a vector is also called its length or magnitude. In the case of Euclidean space R^n, the function defined by :\ is a norm called the Euclidean norm. When the real numbers R are considered as the one-dimensional vector space R^1, the absolute value is a Norm (mathematics) The complex absolute value is a special case of the norm in an inner product space, which is identical to the Euclidean norm when the complex plane is identified as the Euclidean planeR^2. Composition algebras Every composition algebra A has an involution (mathematics) The real numbers R, complex | Wikipedia:Absolute value |
numbers C, and quaternions H are all composition algebras with norms given by definite quadratic forms. The absolute value in these division algebras is given by the square root of the composition | Wikipedia:Absolute value |
an involution (mathematics) The real numbers R, complex numbers C, and quaternions H are all composition algebras with norms given by definite quadratic forms. The absolute value in these division algebras is given by the square root of the composition algebra norm. In general the norm of a composition algebra may be a quadratic form that is not definite and has null vectors. However, as in the case of division algebras, when an element x has a non-zero norm, then x has a multiplicative inverse given by x*/N(x). See also *Least absolute values Notes References * Bartle; Sherbert; Introduction to real analysis (4th ed.), John Wiley & Sons, 2011 . * Nahin, Paul J.; An Imaginary Tale; Princeton University Press; (hardcover, 1998). . * Mac Lane, Saunders, Garrett Birkhoff, Algebra, American Mathematical Soc., 1999. . * Mendelson, Elliott, ''Schaum's Outline of Beginning Calculus'', McGraw-Hill Professional, 2008. . * O'Connor, J.J. and Robertson, E.F.; "Jean Robert Argand". * Schechter, Eric; Handbook of Analysis and Its Foundations, pp.259–263, "Absolute Values", Academic Press (1997) . External links * * * Category:Special functions Category:Real numbers Category:Norms (mathematics) | Wikipedia:Absolute value |
APR April is the fourth month of the year in the Gregorian calendar April is commonly associated with the season of spring (season) History The Romans gave this month the Latin name Aprilis but the derivation of this name is uncertain. The traditional etymology is from the verb aperire, "to open", in allusion to its being the season when trees and flowers begin to "open", which is supported by comparison with the modern Greek use of wikt:άνοιξη#Greek April was the second month of the earliest Roman calendar, In History of China The month April originally had 30 days; Numa Pompilius made it 29 days long; finally, Julius Caesar'scalendar reform made it 30days long again, which was not changed in the calendar revision of Julian calendar In Ancient Rome, the festival of Cerealia was held for seven days from mid-to-late April, but exact dates are still being determined. Feriae Latinae was also held in April, with the date varying. Other ancient Roman observances include Veneralia (April 1), Megalesia (April 10–16), Fordicidia (April 15), Parilia (April 21), Vinalia The Lyrids meteor shower appears on April 16 – April 26 each year, with the peak generally occurring on April 22. The Eta Aquariids meteor shower also appears in April. It is visible from April 21 to May 20 each year, with peak activity on or around May 6. The Pi Puppids appear on April 23, but only in years around the parent comet'sperihelion date. The Virginids also shower at various dates in April. The "Days of April" (''journées d'avril) is a name assigned in French history to a July Monarchy#April 1834 insurrections flower Observances This list does not necessarily imply official status or general observance.'' Month-long * In Catholic Church * National Pet Month (UK) United States * Arab Americans#Arab American Heritage Month * Autism Awareness Month * Cancer Control Month * Community colleges in the | Wikipedia:April |
official status or general observance.'' Month-long * In Catholic Church * National Pet Month (UK) United States * Arab Americans#Arab American Heritage Month * Autism Awareness Month * Cancer Control Month * Community colleges in the United States * Confederate History Month (Alabama, Florida, Georgia (U.S. State) * Financial Literacy Month * Jazz Appreciation Month * Joint Policy Board for Mathematics * Military brat (U.S. subculture) * National Poetry Month * National Poetry Writing Month * American Occupational Therapy Association * List of observances in the United States by presidential proclamation#Annual special months recognized by presidential proclamation * National Volunteer Month * Parkinson's Disease Foundation#Parkinson's Advocates in Research * Rosacea Awareness Month * Sexual Assault Awareness Month United States food months * Fresh Florida Tomato Month * National Food Month * National Grilled Cheese Month * National Pecan Month * National Soft Pretzel Month * National Soyfoods Month Non-Gregorian ''(All Baha'i, Islamic, and Jewish observances begin at the sundown prior to the date listed, and end at sundown of the date in question unless otherwise noted.)'' * List of observances set by the Bahá'í calendar * List of observances set by the Chinese calendar * List of observances set by the Hebrew calendar * List of observances set by the Islamic calendar * List of observances set by the Solar Hijri calendar Movable Variable; 2021 dates shown * Youth Homelessness Matters Day * Public holidays in Kiribati * Head and Neck Cancer Alliance#Oral, Head and Neck Cancer Awareness Week * List of observances in the United States by presidential proclamation#Annual special weeks recognized by presidential proclamation * Crime Victims' Rights Week (United States): April 19–25 * National Volunteer Week: April 19–25 * European Immunization Week: April 20–26 * Day of Silence (United States): April 24 * Pay it forward#1999 novel, film and subsequent projects * Denim Day: April 29 (International | Wikipedia:April |
Week (United States): April 19–25 * National Volunteer Week: April 19–25 * European Immunization Week: April 20–26 * Day of Silence (United States): April 24 * Pay it forward#1999 novel, film and subsequent projects * Denim Day: April 29 (International observance) * Day of Dialogue (United States) * Vaccination Week In The Americas * See: List of movable Western Christian observances * See: List of movable Eastern Christian observances First Wednesday * Childhelp#Community outreach First Saturday * Ulcinj Municipality Day (Ulcinj, Montenegro) First Sunday * Daylight saving time ends (Australia and New Zealand) * Geologists Day (former Soviet Union countries) * Kanamara Matsuri (Kawasaki, Kanagawa * Opening Day (United States) First full week * National Library Week (United States) ** National Library Week ** Bookmobile#National Bookmobile Day * American Public Health Association#National Public Health Week * Association of Public-Safety Communications Officials-International#Events Second Wednesday * International Day of Pink Second Thursday * National Former Prisoner of War Recognition Day (United States) Second Friday * Public holidays in Liberia * Public holidays in Russia#Popular holidays which are not public holidays * List of festivals and events in Kamakura#April Second Sunday * Children's Day#Peru Week of April 14 * Pan American Day Third Wednesday * Administrative Professionals Day (New Zealand) Third Thursday * National High Five Day (United States) Third Saturday * Record Store Day (International observance) Last full week of April * Administrative Professionals Day * World Immunization Week Week of April 23 * Canada Book Day Week of the new moon * International Dark Sky Week (United States) Third Monday * Patriots' Day (Massachusetts, Maine, United States) * Queen's Official Birthday#Other countries and territories * Sechseläuten (Zurich, Switzerland) Wednesday of last full week of April * Administrative Professionals Day | Wikipedia:April |
Dark Sky Week (United States) Third Monday * Patriots' Day (Massachusetts, Maine, United States) * Queen's Official Birthday#Other countries and territories * Sechseläuten (Zurich, Switzerland) Wednesday of last full week of April * Administrative Professionals Day (Hong Kong, North America) First Thursday after April 18 * First Day of Summer (Iceland) Fourth Thursday * Take Our Daughters and Sons to Work Day (United States) Last Friday * Arbor Day (United States) * Día de la Chupina (Rosario, Argentina) Last Friday in April to first Sunday in May * Arbor Day Last Saturday * Children's Day (Colombia) * Rebuilding Together#National Rebuilding Day * The Fragrance Foundation#National Sense of Smell Day * World Tai Chi and Qigong Day Last Sunday * Flag Day (Åland, Finland) * Public holidays in Turkmenistan April 27 (April 26 if April 27 is a Sunday) * Koningsdag (Netherlands) Last Monday * Confederate Memorial Day (Alabama, Georgia (U.S. state), and Mississippi, United States) Last Wednesday * International Noise Awareness Day Fixed at the Circus Maximus * April 1 ** April Fools' Day ** Arbor Day#Tanzania ** Civil Service Day (Thailand) ** Public holidays in Cyprus ** Edible Book Day ** Fossil Fools Day ** Kha b-Nisan (Assyrian people) ** National Science Day (Thailand) ** Odisha Day (Odisha, India) ** Start of National Prostate Health Month#Related observances ** Season for Nonviolence January 30 – April 4 * April 2 ** International Children's Book Day (International observance) ** Malvinas Day (Argentina) ** List of food days#April ** Thai Heritage Conservation Day (Thailand) ** Unity of Peoples of Russia and Belarus Day (Belarus) ** World Autism Awareness Day (International observance) * April 3 * April 4 ** Children's Day (Hong Kong, Taiwan) ** Independence Day (Senegal) ** International observance#April ** Peace Day (Angola) * April 5 ** Children's Day | Wikipedia:April |
and Belarus Day (Belarus) ** World Autism Awareness Day (International observance) * April 3 * April 4 ** Children's Day (Hong Kong, Taiwan) ** Independence Day (Senegal) ** International observance#April ** Peace Day (Angola) * April 5 ** Children's Day (Palestinian territories) ** List of food days#April ** Sikmogil (South Korea) * April 6 ** Public holidays in Thailand ** National Beer Day (United Kingdom) ** New Beer's Eve (United States) ** Tartan Day (United States & Canada) * April 7 ** Flag Day (Slovenia) ** Genocide Memorial Day (Rwanda), and its related observance: *** International Day of Reflection on the 1994 Rwanda Genocide (United Nations) ** Motherhood and Beauty Day (Armenia) ** National Beer Day (United States) ** Sheikh Abeid Amani Karume Day (Tanzania) ** Public holidays in Mozambique ** World Health Day (International observance) * April 8 ** Buddha's Birthday (Japan only, other countries follow different calendars) ** Feast of the Third Day of the Writing of the Book of the Law ** International Romani Day (International observance) * April 9 ** Anniversary of the German Invasion of Denmark (Denmark) ** Baghdad Liberation Day (Iraqi Kurdistan) ** Constitution Day (Kosovo) ** Day of National Unity (Georgia) ** Day of the Finnish Language (Finland) ** Day of Valor or Araw ng Kagitingan (Philippines) ** Feast of the Second Day of the Writing of the Book of the Law (Thelema) ** List of food days#Global or international ** Martyr's Day (Tunisia) ** National Former Prisoner of War Recognition Day (United States) ** Ásatrú holidays#The Troth ** Vimy Ridge Day (Canada) * April 10 ** Day of the Builder (Azerbaijan) ** Feast of the Third Day of the Writing | Wikipedia:April |
of the Book of the Law (Thelema) ** Siblings Day (International observance) * April 11 ** Juan Santamaría Day, anniversary of his death in the Second Battle of Rivas. (Costa Rica) ** International Louie Louie Day ** List of food days#April ** World Parkinson's | Wikipedia:April |
the Law (Thelema) ** Siblings Day (International observance) * April 11 ** Juan Santamaría Day, anniversary of his death in the Second Battle of Rivas. (Costa Rica) ** International Louie Louie Day ** List of food days#April ** World Parkinson's Day * April 12 ** Children's Day (Bolivia and Haiti) ** Commemoration of first human in space by Yuri Gagarin: *** Cosmonautics Day (Russia) *** International Day of Human Space Flight *** Yuri's Night (International observance) ** Halifax Day (North Carolina) ** List of food days#April ** National Redemption Day (Liberia) * April 13 ** Jefferson's Birthday (United States) ** Coma Patients' Day ** Teachers' Day#Dates by country/region ** First day of Thingyan (Myanmar) (April 13–16) ** Remembrance days in Slovakia * April 14 ** Okinawan festivals and observances ** B. R. Ambedkar ** Black Day (South Korea) ** Commemoration of Anfal Genocide Against the Kurds (Iraqi Kurdistan) ** Dhivehi Language Day (Maldives) ** Day of Mologa (Yaroslavl Oblast, Russia) ** Day of the Georgian language (Georgia (country)) ** Emancipation Day ** N'Ko Alphabet Day (Mande languages ** Pohela Boishakh (Bangladesh) ** Pana Sankranti (Odisha, India) ** Puthandu (Tamils) (India, Malaysia, Singapore, Sri Lanka) ** Second day of Songkran (Thailand) ** Pan American Day (several countries in the Americas) ** The first day of Takayama Festival ** Vaisakh (Punjab (region) ** Youth Day (Angola) * April 15 ** Day of the Sun (North Korea). ** Hillsborough disaster#Memorials ** Jackie Robinson Day (United States) ** Pohela Boishakh (West Bengal, India) (Note: | Wikipedia:April |
celebrated on April 14 in Bangladesh) ** Last day of Songkran (Thailand) ** Tax Day, the official deadline for filing an individual Tax return (United States) ** Universal Day of Culture ** World Art Day * April 16 ** Birthday of José de Diego (Puerto Rico, United States) ** Birthday of Queen Margrethe II (Denmark) ** Emancipation Day (Washington, D.C., United States) ** Foursquare Day (International observance) ** Memorial Day for the | Wikipedia:April |
World Art Day * April 16 ** Birthday of José de Diego (Puerto Rico, United States) ** Birthday of Queen Margrethe II (Denmark) ** Emancipation Day (Washington, D.C., United States) ** Foursquare Day (International observance) ** Memorial Day for the Victims of the Holocaust (Hungary) ** List of awareness days#April ** Remembrance of Chemical Attack on Balisan and Sheikh Wasan (Iraqi Kurdistan) ** World Voice Day * April 17 ** Evacuation Day (Syria) ** FAO Day (Iraq) ** Flag Day (American Samoa) ** Malbec World Day ** List of food days#April ** List of food days#Italy ** Public holidays in Gabon ** World Hemophilia Day * April 18 ** Anniversary of the Victory over the Teutonic Knights in the Battle of the Ice, 1242 (Russia) ** Army Day (Iran) ** Coma Patients' Day (Poland) ** Día del Amigo ** Independence Day (Zimbabwe) ** International Day For Monuments and Sites ** Invention Day (Japan) * April 19 ** Army Day (Brazil) ** Beginning of the Independence Movement (Venezuela) ** History of lysergic acid diethylamide#"Bicycle Day" ** Dutch-American Friendship Day (United States) ** Holocaust Remembrance Day (Poland) ** Indigenous Peoples Day (Brazil) ** King Mswati III'sbirthday (Eswatini) ** Landing of the 33 Patriots Day (Uruguay) ** List of food days#April ** List of food days#April ** Primrose Day (United Kingdom) * April 20 ** 420 (cannabis culture) (International) ** UN Chinese Language Day (United Nations) * April 21 ** Natale di Roma(Italy) ** Muster (Texas A&M University)#A. and M. Day ** Civil Services of India#Civil Services Day ** Public holidays in Russia#Regional public holidays ** Grounation Day | Wikipedia:April |
(Rastafari movement) ** Public holidays in Mexico#Civic holidays ** Public holidays in North Korea ** Kartini Day (Indonesia) ** Public holidays in Russia ** Arbor Day#Kenya ** San Jacinto Day (Texas) ** Queen's Official Birthday#Other countries and territories ** Public holidays in Brazil ** Vietnam Book Day (Vietnam) * April 22 ** Discovery Day (Brazil) ** Earth | Wikipedia:April |
(Indonesia) ** Public holidays in Russia ** Arbor Day#Kenya ** San Jacinto Day (Texas) ** Queen's Official Birthday#Other countries and territories ** Public holidays in Brazil ** Vietnam Book Day (Vietnam) * April 22 ** Discovery Day (Brazil) ** Earth Day (International observance) and its related observance: *** International Mother Earth Day ** Holocaust Memorial Days ** List of food days#April * April 23 ** Castile and León Day (Castile and León, Spain) ** German Apples Day ** Conch Republic ** International Pixel-Stained Technopeasant Day ** Khongjom Day (Manipur, India) ** National Sovereignty and Children's Day (Turkey and Northern Cyprus) ** Navy Day (China) ** St George's Day (England) and its related observances: *** Canada Book Day (Canada) *** St George's Day#Catalonia *** World Book Day ** UN English Language Day (United Nations) * April 24 ** Armenian Genocide Remembrance Day (Armenia) ** Concord Day (Niger) ** Children's Day (Zambia) ** Democracy Day (Nepal) ** Fashion Revolution Day ** Flag Day (Ireland) ** International Sculpture Day ** Kapyong Day (Australia) ** Labour Day#Bangladesh ** National Panchayati Raj Day (India) ** List of food days#April ** Republic Day (The Gambia) ** St Mark's Eve (Western Christianity) ** World Day for Laboratory Animals * April 25 ** Anniversary of the First Cabinet of Kurdish Government (Iraqi Kurdistan) ** Anzac Day (Australia, New Zealand) ** Arbor Day (Germany) ** DNA Day ** Feast of Saint Mark (Western Christianity) ** Flag Day (Faroe Islands) ** Public holidays in Eswatini ** Freedom Day (Portugal) ** Liberation Day (Italy) ** Rogation Day ** Military Foundation Day (North Korea) ** List of food days#April ** | Wikipedia:April |
Parental Alienation Awareness Day ** Red Hat Society Day ** Sinai Liberation Day (Egypt) ** World Malaria Day * April 26 ** Chernobyl disaster related observances: *** International Duties Memorial Day *** Day of Remembrance of the Chernobyl tragedy (Belarus) ** Confederate Memorial Day (Florida, United States) ** Hug A Friend Day ** Lesbian | Wikipedia:April |
** World Malaria Day * April 26 ** Chernobyl disaster related observances: *** International Duties Memorial Day *** Day of Remembrance of the Chernobyl tragedy (Belarus) ** Confederate Memorial Day (Florida, United States) ** Hug A Friend Day ** Lesbian Visibility Day ** List of food days#April ** Old Permic alphabet ** Union Day (Tanzania) ** World Intellectual Property Day * April 27 ** Public holidays in Russia ** Day of the Uprising Against the Occupying Forces (Slovenia) ** Flag Day (Moldova) ** Freedom Day (South Africa) *** UnFreedom Day ** Independence Day (Sierra Leone) ** Public holidays in Togo ** National Day (Mayotte) ** National Day (Sierra Leone) ** List of food days#April ** Flag flying days in Finland * April 28 ** Lawyers' Day (Orissa, India) ** Mujahideen Victory Day (Afghanistan) ** National Day (Sardinia, Italy) ** National Heroes Day (Barbados) ** Restoration of Sovereignty Day (Japan) ** Workers' Memorial Day *** National Day of Mourning (Canada) * April 29 ** Day of Remembrance for all Victims of Chemical Warfare (United Nations) ** International Dance Day (UNESCO) ** Public holidays in Denmark#Other special days ** List of food days#April ** Shōwa Day, traditionally the start of the Golden Week (Japan) * April 30 ** Armed Forces Day (Georgia (country)) ** Flag flying days in Sweden ** Battle of Camarón ** Children's Day (Mexico) ** Public holidays in Thailand ** Honesty Day (United States) ** International Jazz Day (UNESCO) ** Martyrs' Day (Pakistan) ** May Eve, the eve of the first day of summer in the Northern hemisphere (see May 1): *** Beltane begins at sunset in the Northern hemisphere, Samhain begins at sunset in the Southern hemisphere. (Neo-Druidism *** Carodejnice (Czech Republic | Wikipedia:April |
and Slovakia) *** Walpurgis Night (Central and Northern Europe) ** Persian Gulf naming dispute#National Persian Gulf Day ** Reunification Day (Vietnam) ** Public holidays in Russia#Popular holidays which are not public holidays ** Tax return (Canada) ** Teachers' | Wikipedia:April |
(Czech Republic and Slovakia) *** Walpurgis Night (Central and Northern Europe) ** Persian Gulf naming dispute#National Persian Gulf Day ** Reunification Day (Vietnam) ** Public holidays in Russia#Popular holidays which are not public holidays ** Tax return (Canada) ** Teachers' Day (Paraguay) See also * Germanic calendar * List of historical anniversaries * Sinking of the RMS Titanic References External links * National Arbor Day Foundation Category:April Category:Months | Wikipedia:April |
Aug in the August calendar page of the Queen Mary Psalter (fol. 78v), ca. 1310 August is the eighth month of the year in the Julian calendar In the Southern Hemisphere, August is the seasonal equivalent of February in the Northern Hemisphere. In the Northern Hemisphere, August falls in summer. In the Southern Hemisphere, the month falls during winter. In many European countries, August is the holiday month for most workers. Numerous religious holidays occurred during August in ancient Rome. Certain meteor showers take place in August. The Kappa Cygnids occur in August, with yearly dates varying. The Alpha Capricornids meteor shower occurs as early as July 10 and ends around August 10. The Southern Delta Aquariids occur from mid-July to mid-August, with the peak usually around July 28–29. The Perseids, a major meteor shower, typically takes place between July 17 and August 24, with the peak days varying yearly. The star cluster of Messier 30 is best observed around August. Among the aborigines of the Canary Islands, especially among the Guanches of Tenerife, the month of August received the name of Beñesmer or Beñesmen, which was also the harvest festival held that month. The month was originally named Sextilis in Latin because it was the 6th month in the original ten-month Roman calendar under Romulus and Remus In 8 BC, the month was renamed in honor of Emperor Augustus. According to a Senatus consultum quoted by Macrobius, he chose this month because it was the time of several of his great triumphs, including the conquest of Egypt. Commonly repeated lore has it that August has 31 days because Augustus wanted his month to match the length of Julius Caesar's July, but this is an invention of the 13th century scholar Johannes de Sacrobosco. Sextilis had 31 days before it was renamed. It was not chosen for its length. Symbols gemstones stone on calciteAugust'sbirthstones are the peridot, sardonyx, and | Wikipedia:August |
this is an invention of the 13th century scholar Johannes de Sacrobosco. Sextilis had 31 days before it was renamed. It was not chosen for its length. Symbols gemstones stone on calciteAugust'sbirthstones are the peridot, sardonyx, and spinel. Its birth flower is the gladiolus or poppy, meaning beauty, strength of character, love, marriage and family. The Zodiac Observances This list does not necessarily imply official status or general observance. Non-Gregorian: dates (All Baha'i, Islamic, and Jewish observances begin at sundown before the listed date and end at sundown on the date in question unless otherwise noted.) * List of observances set by the Bahá'í calendar * List of observances set by the Chinese calendar * List of observances set by the Hebrew calendar * List of observances set by the Islamic calendar * List of observances set by the Solar Hijri calendar Month-long * Women's Month (South Africa) * American Adventures Month (celebrates vacationing in the Americas) * Children's Eye Health and Safety Month * Digestive Tract Paralysis (DTP) Month * Get Ready for Kindergarten Month * Secret Society of Happy People * Month of Philippine Languages or Buwan ng Wika (Philippines) * Neurosurgery Outreach Month * Psoriasis Awareness Month * Spinal Muscular Atrophy Awareness Month * What Will Be Your Legacy Month United States month-long * National Black Business Month * National Children's Vision and Learning Month * National Immunization Awareness Month * National Princess Peach Month * National Water Quality Month * National Win with Civility Month Food months in the United States * National Catfish Month * National Dippin' Dots Month * National Panini (sandwich) * Peach Month (Australia) * See also Movable Western Christian observances * See also Movable Eastern Christian observances Second to last Sunday in July and the following two weeks * Construction Holiday (Quebec) 1st Saturday * Food | Wikipedia:August |
Peach Month (Australia) * See also Movable Western Christian observances * See also Movable Eastern Christian observances Second to last Sunday in July and the following two weeks * Construction Holiday (Quebec) 1st Saturday * Food Day (Canada) * Brewers Association * List of food days#August 1st Sunday * Armed Forces Day#Ukraine * American Family Day (Arizona, United States) * Children's Day (Uruguay) * Friendship Day (United States) * Forgiveness * Public holidays in Russia#List of other public holidays, commemorative and professional days First full week of August * National Farmer's Market Week (United States) 1st Monday * Public holidays in the Republic of Ireland * Children's Day (Tuvalu) * Civic Holiday (Canada) ** Civic Holiday ** Natal Day (Nova Scotia, Canada) ** Civic Holiday ** Civic Holiday ** Terry Fox#Honours * Public holidays in Iceland * Emancipation Day (Anguilla, Antigua, The Bahamas, British Virgin Islands, Dominica, Grenada, Saint Kitts and Nevis) * Public holidays in Zambia * Public holidays in Barbados * Public holidays in Samoa * National Day (Jamaica) * Picnic Day (Australian holiday) * Public holidays in Bermuda * Youth Day (Kiribati) 1st Tuesday * National Night Out (United States) 1st Friday * International Beer Day 2nd Saturday * Public holidays in Russia#List of other public holidays, commemorative and professional days Sunday on or closest to August 9 * National Peacekeepers' Day (Canada) 2nd Sunday * Children's Day (Argentina, Chile, Uruguay) * Father's Day (Brazil, Samoa) * Melon Day (Turkmenistan) * Navy Day#Bulgaria * National Day (Singapore) 2nd Monday * Public holidays in Zimbabwe * Victory Day (Hawaii and Rhode Island, United States) 2nd Tuesday * Public holidays in Zimbabwe 3rd Saturday * National Honey Bee Day (United States) 3rd Sunday * Children's Day (Argentina, Peru) * National Grandparents Day 3rd Monday | Wikipedia:August |
Rhode Island, United States) 2nd Tuesday * Public holidays in Zimbabwe 3rd Saturday * National Honey Bee Day (United States) 3rd Sunday * Children's Day (Argentina, Peru) * National Grandparents Day 3rd Monday * Discovery Day (Yukon, Canada) * Hartjesdag * National Mourning Day (Bangladesh) 3rd Friday * Hawaii Admission Day (Hawaii, United States) Last Thursday * List of food days#United Kingdom Last Sunday * Alexey Stakhanov#Biography * National Grandparents Day (Taiwan) Last Monday * Father's Day (South Sudan) * National Heroes' Day#National Heroes' Day in the Philippines * Liberation Day (Hong Kong) * Bank Holiday Fixed Gregorian * Emancipation Day * International Clown Week (August 1–7) * World Breastfeeding Week (August 1–7) * August 1 ** Armed Forces Day (China) ** Armed Forces Day (Lebanon) ** Azerbaijani Language and Alphabet Day (Azerbaijan) ** Emancipation Day (Barbados, Guyana, Jamaica, Saint Vincent and the Grenadines, St. Lucia, Trinidad and Tobago, Turks and Caicos Islands) ** Imbolc (Neopaganism, Southern Hemisphere only) ** Lammas (England, Scotland, Neopaganism, Northern Hemisphere only) ** Lughnasadh (Gaels, Ireland, Scotland, Neopaganism, Northern Hemisphere only) ** Minden Day (United Kingdom) ** National Day (Benin) ** List of food days#August ** Culture of Tonga#Public Holidays ** Pachamama Raymi (Quechua people in Ecuador and Peru) ** Public holidays in the Democratic Republic of the Congo ** Feast of the Cross#August 1 ** Statehood Day (Colorado) ** Swiss National Day (Switzerland) ** Victory Day (Cambodia, Laos, Vietnam) ** Scouts' Day#World Scout Scarf Day ** Yorkshire Day (Yorkshire, England) * August 2 ** Armed Forces of Ukraine#Military holidays ** Cinema of Azerbaijan ** Virgen de los Ángeles ** Armed Forces Day#Russian Federation | Wikipedia:August |
** Republic Day (North Macedonia) * August 3 ** Public holidays in Guinea-Bissau ** Public holidays in Equatorial Guinea ** Esther Earl#Esther Day ** Flag Day (Venezuela) ** Independence Day (Niger) *** Arbor Day (Niger) | Wikipedia:August |
** Armed Forces Day#Russian Federation ** Republic Day (North Macedonia) * August 3 ** Public holidays in Guinea-Bissau ** Public holidays in Equatorial Guinea ** Esther Earl#Esther Day ** Flag Day (Venezuela) ** Independence Day (Niger) *** Arbor Day (Niger) ** Armed Forces Day#Venezuela ** List of food days#August ** List of food days#August * August 4 ** Coast Guard Day (United States) ** Constitution Day (Cook Islands) ** Matica slovenská Day (Slovakia) ** Revolution Day (Burkina Faso) * August 5 ** Dedication of the Basilica of St Mary Major (Catholic Church) ** Public holidays in Burkina Faso ** Freshpair#National Underwear Day ** Victory Day (Croatia) * August 6 ** Feast of the Transfiguration ** Zayed bin Sultan Al Nahyan ** Hiroshima Peace Memorial Ceremony (Hiroshima, Japan) ** Public holidays in Bolivia ** Public holidays in Jamaica ** Public holidays in Russia#List of other public holidays, commemorative and professional days * August 7 ** Assyrian culture#Premta d-Simele; Martyr's Day ** Public holidays in Colombia ** Public holidays in Saint Kitts and Nevis ** List of national independence days ** Republic Day (Ivory Coast) ** Youth Day (Kiribati) * August 8 ** Public holidays in Iraq ** Father's Day (Taiwan) ** Happiness Happens Day (International observance) ** National Cat Day ** Flag flying days in Sweden ** Nane Nane Day (Tanzania) ** Armed Forces of Ukraine#Military holidays * August 9 ** Days of Military Honour ** International Day of the World's Indigenous People (United Nations) ** National Day (Singapore) ** National Women's Day (South Africa) ** Ásatrú holidays#The Troth * August 10 ** Armed Forces Day#Argentina ** Public holidays in Anguilla ** Public holidays in Ecuador ** Biodiesel#Historical | Wikipedia:August |
background ** List of food days#August * August 11 ** Flag Day (Pakistan) ** List of national independence days ** Mountain Day (Japan) * August 12 ** Glorious Twelfth (United Kingdom) ** Sirikit ** International Youth Day (United Nations) ** Public holidays in Russia#List of | Wikipedia:August |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.