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Oliver Riordan
The Eternity puzzle is a tiling puzzle created by Christopher Monckton and launched by the Ertl Company in June 1999. It was marketed as being practically unsolvable, with a £1 million prize on offer for whoever could solve it within four years. The prize was paid out in October 2000 for a winning solution arrived at by two mathematicians from Cambridge. A follow-up prize puzzle called Eternity II was launched in 2007. Description The puzzle's scope was to fill a large equiangular (but not equilateral) dodecagon board with 209 puzzle pieces. The board is equipped with a triangular grid made of equilateral triangles. Its sides alternate in length: six sides coincide with the grid and are 7 triangles (placed edge-to-edge) long, while the other sides are slightly shorter and measure 8 triangles base-to-tip, which equals 4\sqrt \approx 6.9 edge lengths. Each puzzle piece is a 12- polydrafter (dodecadrafter) made of twelve 30-60-90 triangles (that is, a continuous compound of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eternity Puzzle Board
Eternity, in common parlance, means infinite time that never ends or the quality, condition, or fact of being everlasting or eternal. Classical philosophy, however, defines eternity as what is timeless or exists outside time, whereas sempiternity corresponds to infinite duration. Philosophy Classical philosophy defines eternity as what exists outside time, as in describing timeless supernatural beings and forces, distinguished from sempiternity which corresponds to infinite time, as described in requiem prayers for the dead. Some thinkers, such as Aristotle, suggest the eternity of the natural cosmos in regard to both past and future eternal duration. Boethius defined eternity as "simultaneously full and perfect possession of interminable life". Thomas Aquinas believed that God's eternity does not cease, as it is without either a beginning or an end; the concept of eternity is of divine simplicity, thus incapable of being defined or fully understood by humankind. Thomas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
30-60-90 Triangles
A special right triangle is a right triangle with some regular feature that makes calculations on the triangle easier, or for which simple formulas exist. For example, a right triangle may have angles that form simple relationships, such as 45°–45°–90°. This is called an "angle-based" right triangle. A "side-based" right triangle is one in which the lengths of the sides form ratios of whole numbers, such as 3 : 4 : 5, or of other special numbers such as the golden ratio. Knowing the relationships of the angles or ratios of sides of these special right triangles allows one to quickly calculate various lengths in geometric problems without resorting to more advanced methods. Angle-based "Angle-based" special right triangles are specified by the relationships of the angles of which the triangle is composed. The angles of these triangles are such that the larger (right) angle, which is 90 degrees or radians, is equal to the sum of the other two angles. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1999 Introductions
File:1999 Events Collage.png, From left, clockwise: The funeral procession of King Hussein of Jordan in Amman; the 1999 İzmit earthquake kills over 17,000 people in Turkey; the Columbine High School massacre, one of the first major school shootings in the United States; the Year 2000 problem ("Y2K"), perceived as a major concern in the lead-up to the year 2000; the Millennium Dome opens in London; online music downloading platform Napster is launched, soon a source of online piracy; NASA loses both the Mars Climate Orbiter and the Mars Polar Lander; a destroyed T-55 tank near Prizren during the Kosovo War., 300x300px, thumb rect 0 0 200 200 Death and state funeral of King Hussein rect 200 0 400 200 1999 İzmit earthquake rect 400 0 600 200 Columbine High School massacre rect 0 200 300 400 Kosovo War rect 300 200 600 400 Year 2000 problem rect 0 400 200 600 Mars Climate Orbiter rect 200 400 400 600 Napster rect 400 400 600 600 Millennium Dome 1999 was designated as the Inter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Western Australia
Western Australia (commonly abbreviated as WA) is a state of Australia occupying the western percent of the land area of Australia excluding external territories. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to the south, the Northern Territory to the north-east, and South Australia to the south-east. Western Australia is Australia's largest state, with a total land area of . It is the List of country subdivisions by area, second-largest country subdivision in the world, surpassed only by Russia's Sakha, Sakha Republic. the state has 2.76 million inhabitants percent of the national total. The vast majority (92 percent) live in the South-West Land Division, south-west corner; 79 percent of the population lives in the Perth area, leaving the remainder of the state sparsely populated. The first Europeans to visit Western Australia belonged to the Dutch Dirk Hartog expedition, who visited the Western Australian coast in 1616. The first pe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perth, Western Australia
Perth is the capital and largest city of the Australian state of Western Australia. It is the fourth most populous city in Australia and Oceania, with a population of 2.1 million (80% of the state) living in Greater Perth in 2020. Perth is part of the South West Land Division of Western Australia, with most of the metropolitan area on the Swan Coastal Plain between the Indian Ocean and the Darling Scarp. The city has expanded outward from the original British settlements on the Swan River, upon which the city's central business district and port of Fremantle are situated. Perth is located on the traditional lands of the Whadjuk Noongar people, where Aboriginal Australians have lived for at least 45,000 years. Captain James Stirling founded Perth in 1829 as the administrative centre of the Swan River Colony. It was named after the city of Perth in Scotland, due to the influence of Stirling's patron Sir George Murray, who had connections with the area. It gained ci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perth Arena
Perth Arena (known commercially as ) is an entertainment and sporting arena in the city centre of Perth, Western Australia, used mostly for basketball matches. It is located on Wellington Street near the site of the former Perth Entertainment Centre, and was officially opened on 10 November 2012. Perth Arena is the first stage of the Perth City Link, a major urban renewal and redevelopment project which involves the sinking of the Fremantle railway line to link the Perth central business district directly with Northbridge. About The arena was jointly designed by architectural firms Ashton Raggatt McDougall and Cameron Chisholm Nicol. With its design based on the Eternity puzzle, the venue holds up to 13,910 spectators for tennis events, 14,846 for basketball (the arena's capacity is capped at 13,000 for National Basketball League regular season games) and a maximum of 15,000 for music or rock concerts. The venue has a retractable roof, 36 luxury appointed corporate suites ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Public Relations
Public relations (PR) is the practice of managing and disseminating information from an individual or an organization (such as a business, government agency, or a nonprofit organization) to the public in order to influence their perception. Public relations and publicity differ in that PR is controlled internally, whereas publicity is not controlled and contributed by external parties. Public relations may include an organization or individual gaining exposure to their audiences using topics of public interest and news items that do not require direct payment. The exposure mostly is media-based. This differentiates it from advertising as a form of marketing communications. Public relations aims to create or obtain coverage for clients for free, also known as earned media, rather than paying for marketing or advertising also known as paid media. But in the early 21st century, advertising is also a part of broader PR activities. An example of good public relations would b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crimonmogate
Crimonmogate is an estate near Crimond, Aberdeenshire. The estate formed part of Lonmay parish, dates back to the 14th century, and was included in the lands owned by the powerful Earls of Erroll. The estate was sold by Mary Hay, 14th Countess of Erroll, in the 1730s. Major development commenced when the land was owned by the merchant Patrick Milne in the late 18th and early 19th centuries and the estate is now most famous for Crimonmogate House, designed by the Aberdeen architect Archibald Simpson for Milne. The Greek Revival building is protected as a category A listed building and the grounds are included on the Inventory of Gardens and Designed Landscapes in Scotland. After Milne's death the estate passed to the Bannerman family, who continued to develop the lands and completed the construction of the mansion, also adding a mansard roof later. Simpson was commissioned to design further structures within the estate. Eventually, through marriage in the 20th century, the es ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NRICH
The Millennium Mathematics Project (MMP) was set up within the University of Cambridge in England as a joint project between the Faculties of Mathematics and Education in 1999. The MMP aims to support maths education for pupils of all abilities from ages 5 to 19 and promote the development of mathematical skills and understanding, particularly through enrichment and extension activities beyond the school curriculum, and to enhance the mathematical understanding of the general public. The project was directed by John Barrow from 1999 until September 2020. Programmes The MMP includes a range of complementary programmes: *The NRICH website publishes free mathematics education enrichment material for ages 5 to 19. NRICH material focuses on problem-solving, building core mathematical reasoning and strategic thinking skills. In the academic year 2004/5 the website attracted over 1.7 million site visits (more than 49 million hits). *''Plus Magazine'' is a free online maths magazine for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Underwriters
Underwriting (UW) services are provided by some large financial institutions, such as banks, insurance companies and investment houses, whereby they guarantee payment in case of damage or financial loss and accept the financial risk for liability arising from such guarantee. An underwriting arrangement may be created in a number of situations including insurance, issues of security in a public offering, and bank lending, among others. The person or institution that agrees to sell a minimum number of securities of the company for commission is called the underwriter. History The term "underwriting" derives from the Lloyd's of London insurance market. Financial backers (or risk takers), who would accept some of the risk on a given venture (historically a sea voyage with associated risks of shipwreck) in exchange for a premium, would literally write their names under the risk information that was written on a Lloyd's slip created for this purpose. Securities underwriting In the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Backtracking Search
Backtracking is a class of algorithms for finding solutions to some computational problems, notably constraint satisfaction problems, that incrementally builds candidates to the solutions, and abandons a candidate ("backtracks") as soon as it determines that the candidate cannot possibly be completed to a valid solution. The classic textbook example of the use of backtracking is the eight queens puzzle, that asks for all arrangements of eight chess queens on a standard chessboard so that no queen attacks any other. In the common backtracking approach, the partial candidates are arrangements of ''k'' queens in the first ''k'' rows of the board, all in different rows and columns. Any partial solution that contains two mutually attacking queens can be abandoned. Backtracking can be applied only for problems which admit the concept of a "partial candidate solution" and a relatively quick test of whether it can possibly be completed to a valid solution. It is useless, for example, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
30-60-90 Triangle
A special right triangle is a right triangle with some regular feature that makes calculations on the triangle easier, or for which simple formulas exist. For example, a right triangle may have angles that form simple relationships, such as 45°–45°–90°. This is called an "angle-based" right triangle. A "side-based" right triangle is one in which the lengths of the sides form ratios of whole numbers, such as 3 : 4 : 5, or of other special numbers such as the golden ratio. Knowing the relationships of the angles or ratios of sides of these special right triangles allows one to quickly calculate various lengths in geometric problems without resorting to more advanced methods. Angle-based "Angle-based" special right triangles are specified by the relationships of the angles of which the triangle is composed. The angles of these triangles are such that the larger (right) angle, which is 90 degrees or radians, is equal to the sum of the other two angles ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
