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Rattleback
A rattleback is a semi-ellipsoidal top which will rotate on its axis in a preferred direction. If spun in the opposite direction, it becomes unstable, "rattles" to a stop and reverses its spin to the preferred direction. This spin-reversal appears to violate the law of the conservation of angular momentum. Moreover, for most rattlebacks the motion will happen when the rattleback is spun in one direction, but not when spun in the other. Some exceptional rattlebacks will reverse when spun in either direction. This makes the rattleback a physical curiosity that has excited human imagination since prehistoric times. A rattleback may also be known as a "anagyre", "(rebellious) celt", "Celtic stone", "druid stone", "rattlerock", "Robinson Reverser", "spin bar", "wobble stone" (or "wobblestone") and by product names including "ARK", "Bizzaro Swirl", "Space Pet" and "Space Toy". History Archeologists who investigated ancient Celtic and Egyptian sites in the 19th century found celts whi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rattleback In Action
A rattleback is a semi-ellipsoidal top which will rotate on its axis in a preferred direction. If spun in the opposite direction, it becomes unstable, "rattles" to a stop and reverses its spin to the preferred direction. This spin-reversal appears to violate the law of the angular momentum#Conservation of angular momentum, conservation of angular momentum. Moreover, for most rattlebacks the motion will happen when the rattleback is spun in one direction, but not when spun in the other. Some exceptional rattlebacks will reverse when spun in either direction. This makes the rattleback a physical curiosity that has excited human imagination since prehistoric times. A rattleback may also be known as a "anagyre", "(rebellious) celt (tool), celt", "Celtic stone", "druid stone", "rattlerock", "Robinson Reverser", "spin bar", "wobble stone" (or "wobblestone") and by product names including "ARK", "Bizzaro Swirl", "Space Pet" and "Space Toy". History Archeologists who investigated ancien ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RATTLEBACK - ANAGYRE -(GAEL 24 Inches) - Emmanuel Peluchon
A rattleback is a semi-ellipsoidal top which will rotate on its axis in a preferred direction. If spun in the opposite direction, it becomes unstable, "rattles" to a stop and reverses its spin to the preferred direction. This spin-reversal appears to violate the law of the conservation of angular momentum. Moreover, for most rattlebacks the motion will happen when the rattleback is spun in one direction, but not when spun in the other. Some exceptional rattlebacks will reverse when spun in either direction. This makes the rattleback a physical curiosity that has excited human imagination since prehistoric times. A rattleback may also be known as a "anagyre", "(rebellious) celt", "Celtic stone", "druid stone", "rattlerock", "Robinson Reverser", "spin bar", "wobble stone" (or "wobblestone") and by product names including "ARK", "Bizzaro Swirl", "Space Pet" and "Space Toy". History Archeologists who investigated ancient Celtic and Egyptian sites in the 19th century found celts whi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Celt (tool)
In archaeology, a celt is a long, thin, prehistoric, stone or bronze tool similar to an adze, hoe, or axe. A shoe-last celt was a polished stone tool used during the early European Neolithic for felling trees and woodworking. Etymology The term "celt" seems to have come about from a copyist's error in many medieval manuscript copies of Job 19:24 in the Latin Vulgate Bible, which became enshrined in the authoritative Sixto-Clementine printed edition of 1592. Where all earlier versions (the Codex Amiatinus, for example) have ''vel certe'' (the Latin for 'but surely'), the Sixto-Clementine has ''vel celte''. The Hebrew has לעד (''lā‘aḏ'') at this point, which means 'forever'. The editors of the Oxford English Dictionary " nclineto the belief that ''celtis'' was a phantom word," simply a misspelling of ''certe''. However, some scholars over the years have treated ''celtis'' as a real Latin word. From the context of Job 19:24 ("Oh, that my words were inscribed with an i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Educational Toys
Educational toys (sometimes also called "instructive toys") are objects of play, generally designed for children, which are expected to stimulate learning. They are often intended to meet an educational purpose such as helping a child develop a particular skill or teaching a child about a particular subject. They often simplify, miniaturize, or even model activities and objects used by adults. Although children are constantly interacting with and learning about the world, many of the objects they interact with and learn from are not toys. Toys are generally considered to be specifically built for children's use. A child might play with and learn from a rock or a stick, but it would not be considered an educational toy because 1) it is a natural object, not a designed one, and 2) it has no expected educational purpose. The difference lies in perception or reality of the toy's intention and value. An educational toy is expected to educate. It is expected to instruct, promot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gilbert Walker (physicist)
Sir Gilbert Thomas Walker (14 June 1868 – 4 November 1958) was an English physicist and statistician of the 20th century. Walker studied mathematics and applied it to a variety of fields including aerodynamics, electromagnetism and the analysis of time-series data before taking up a teaching position at the University of Cambridge. Although he had no experience in meteorology, he was recruited for a post in the Indian Meteorological Department where he worked on statistical approaches to predict the monsoons. He developed the methods in the analysis of time-series data that are now called the Yule-Walker equations. He is known for his groundbreaking description of the Southern Oscillation, a major phenomenon of global climate, and for discovering what is named after him as the Walker circulation, and for greatly advancing the study of climate in general. He was also instrumental in aiding the early career of the Indian mathematical prodigy, Srinivasa Ramanujan. Early ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flight Dynamics
Flight dynamics in aviation and spacecraft, is the study of the performance, stability, and control of vehicles flying through the air or in outer space. It is concerned with how forces acting on the vehicle determine its velocity and attitude with respect to time. For a fixed-wing aircraft, its changing orientation with respect to the local air flow is represented by two critical angles, the angle of attack of the wing ("alpha") and the angle of attack of the vertical tail, known as the sideslip angle ("beta"). A sideslip angle will arise if an aircraft yaws about its centre of gravity and if the aircraft sideslips bodily, i.e. the centre of gravity moves sideways.Flightwise - Volume 2 - Aircraft Stability And Control, Chris Carpenter 1997, Airlife Publishing Ltd., , p.145 These angles are important because they are the principal source of changes in the aerodynamic forces and moments applied to the aircraft. Spacecraft flight dynamics involve three main forces: propulsive (ro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Articles Containing Video Clips
Article often refers to: * Article (grammar), a grammatical element used to indicate definiteness or indefiniteness * Article (publishing), a piece of nonfictional prose that is an independent part of a publication Article may also refer to: Government and law * Article (European Union), articles of treaties of the European Union * Articles of association, the regulations governing a company, used in India, the UK and other countries * Articles of clerkship, the contract accepted to become an articled clerk * Articles of Confederation, the predecessor to the current United States Constitution *Articles of Impeachment, Article of Impeachment, a formal document and charge used for impeachment in the United States * Articles of incorporation, for corporations, U.S. equivalent of articles of association * Articles of organization, for limited liability organizations, a U.S. equivalent of articles of association Other uses * Article, an HTML element, delimited by the tags and * Ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Novelty Items
Novelty (derived from Latin word ''novus'' for "new") is the quality of being new, or following from that, of being striking, original or unusual. Novelty may be the shared experience of a new cultural phenomenon or the subjective perception of an individual. From the meaning of being unusual usage is derived the concept of the novelty dance (a type of dance that is popular for being unusual or humorous); the novelty song (a musical item that capitalizes on something new, unusual, or a current fad); the novelty show (a competition or display in which exhibits or specimens are in way some novel); and novelty architecture (a building or other structure that is interesting because it has an amusing design). It is also this sense that applies to a novelty item, a small manufactured adornment, toy or collectible. These, in turn are often used as promotional merchandise in marketing. The Glossary of chess#N, chess term, novelty, is used for a move in chess which has never been played bef ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wooden Toys
Wood is a porous and fibrous structural tissue found in the stems and roots of trees and other woody plants. It is an organic materiala natural composite of cellulose fibers that are strong in tension and embedded in a matrix of lignin that resists compression. Wood is sometimes defined as only the secondary xylem in the stems of trees, or it is defined more broadly to include the same type of tissue elsewhere such as in the roots of trees or shrubs. In a living tree it performs a support function, enabling woody plants to grow large or to stand up by themselves. It also conveys water and nutrients between the leaves, other growing tissues, and the roots. Wood may also refer to other plant materials with comparable properties, and to material engineered from wood, or woodchips or fiber. Wood has been used for thousands of years for fuel, as a construction material, for making tools and weapons, furniture and paper. More recently it emerged as a feedstock for the produ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Traditional Toys
A tradition is a belief or behavior (folk custom) passed down within a group or society with symbolic meaning or special significance with origins in the past. A component of cultural expressions and folklore, common examples include holidays or impractical but socially meaningful clothes (like lawyers' wigs or military officers' spurs), but the idea has also been applied to social norms such as greetings. Traditions can persist and evolve for thousands of years—the word ''tradition'' itself derives from the Latin ''tradere'' literally meaning to transmit, to hand over, to give for safekeeping. While it is commonly assumed that traditions have an ancient history, many traditions have been invented on purpose, whether that be political or cultural, over short periods of time. Various academic disciplines also use the word in a variety of ways. The phrase "according to tradition", or "by tradition", usually means that whatever information follows is known only by oral tradition, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Puzzles
A puzzle is a game, problem, or toy that tests a person's ingenuity or knowledge. In a puzzle, the solver is expected to put pieces together ( or take them apart) in a logical way, in order to arrive at the correct or fun solution of the puzzle. There are different genres of puzzles, such as crossword puzzles, word-search puzzles, number puzzles, relational puzzles, and logic puzzles. The academic study of puzzles is called enigmatology. Puzzles are often created to be a form of entertainment but they can also arise from serious mathematical or logical problems. In such cases, their solution may be a significant contribution to mathematical research. Etymology The ''Oxford English Dictionary'' dates the word ''puzzle'' (as a verb) to the end of the 16th century. Its earliest use documented in the ''OED'' was in a book titled ''The Voyage of Robert Dudley...to the West Indies, 1594–95, narrated by Capt. Wyatt, by himself, and by Abram Kendall, master'' (published circa 1595). ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flinn Scientific Inc
Flinn may refer to: *Flinn (surname), of Irish origin * Flinn, Mississippi *Flinn, West Virginia * Flinn Township, Lawrence County, Indiana, dissolved in 1911 See also * Kelly Flinn incident *Flin, commune in Meurthe-et-Moselle department in France *Flynn Flynn is an Irish surname or first name, an anglicised form of the Irish ''Ó Floinn'', meaning "descendant of Flann" (a byname meaning "reddish (complexion)" or "ruddy"). The name is more commonly used as a surname rather than a first name. A ... (surname) * Flynn (other) {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
_-_Emmanuel_Peluchon.jpg "Click for more on -> Rattleback")
