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Topopolis
A topopolis is a proposed tube-shaped space habitat, rotating to produce artificial gravity via centrifugal force on the inner surface, which is extended into a loop around the local planet or star. The concept was invented by writer Patrick Gunkel. Varieties of topopolises and similar fictional structures A topopolis has been compared to an O'Neill cylinder, or a McKendree cylinder, that has been extended in length so that it encircles a star. A “normal” topopolis would be hundreds of millions of miles/kilometers long and at least several miles (kilometers) in diameter. Topopoles can be looped several times around the local star, in a geometric figure known as a torus knot. Topopolises are also called cosmic spaghetti. A topopolis with big enough diameter could theoretically have multiple levels of concentric cylinders. Larry Niven (1974) mentioned the idea in a much-reprinted magazine article "Bigger Than Worlds". Examples in novels Iain M. Banks (2008) depicts a topo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Torus Knot
In knot theory, a torus knot is a special kind of knot that lies on the surface of an unknotted torus in R3. Similarly, a torus link is a link which lies on the surface of a torus in the same way. Each torus knot is specified by a pair of coprime integers ''p'' and ''q''. A torus link arises if ''p'' and ''q'' are not coprime (in which case the number of components is gcd(''p, q'')). A torus knot is trivial (equivalent to the unknot) if and only if either ''p'' or ''q'' is equal to 1 or −1. The simplest nontrivial example is the (2,3)-torus knot, also known as the trefoil knot. Geometrical representation A torus knot can be rendered geometrically in multiple ways which are topologically equivalent (see Properties below) but geometrically distinct. The convention used in this article and its figures is the following. The (''p'',''q'')-torus knot winds ''q'' times around a circle in the interior of the torus, and ''p'' times around its axis of rotational symmetry.. If ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bigger Than Worlds
"Bigger Than Worlds" is an essay by the American science fiction writer Larry Niven (born 1938). It was first published in March 1974 in Analog magazine, and has been anthologized in ''A Hole in Space'' (1974) and in ''Playgrounds of the Mind'' (1991). It reviews a number of proposals, not inconsistent with the known laws of physics, which have been made for habitable artificial astronomical megastructures. Sections After an introduction saying that everyone may not always live on a single planet, the essay is divided into (mostly short) sections having the following titles and brief descriptions: ; The Multi-Generation Ship A generation ship is a slower-than-light spaceship housing some hundreds of people which takes several human generations to complete its journey. It could in principle be built using known technology. ; Gravity Niven can conceive of four ways of generating artificial gravity in a spaceship: (1) centrifugal force; (2) adding mass, e.g. neutronium or a black hol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Playgrounds Of The Mind
''Playgrounds of the Mind'' is a collection of short stories by American writer Larry Niven, published in 1991. It is the sequel to ''N-Space (short story collection), N-Space''. Many of the stories are set in Niven's Known Space universe. There are also excerpts from his ''The Magic Goes Away'' novel series, as well as several stories from his ''The Draco Tavern'' setting (an alien bar) and other sources. Contents * "Thraxisp: A Memoir" * "A Teardrop Falls" * From Inferno (Niven and Pournelle novel), ''Inferno'' (with Jerry Pournelle) * From ''A World Out of Time'' * "Rammer" * From "The Ethics of Madness" * "Becalmed in Hell" * "Wait It Out" * "A Relic of the Empire" * From ''Lucifer's Hammer'' (with Jerry Pournelle) * "The Soft Weapon" * "The Borderland of Sol" * From ''The Ringworld Engineers'' * "What Good Is a Glass Dagger?" * From ''The Magic Goes Away'' * "The Defenseless Dead" * From ''The Patchwork Girl'' * "Leviathan!" * From ''Oath of Fealty (novel), Oath of Fealty'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Analog Science Fiction And Fact
''Analog Science Fiction and Fact'' is an American science fiction magazine published under various titles since 1930. Originally titled ''Astounding Stories of Super-Science'', the first issue was dated January 1930, published by William Clayton, and edited by Harry Bates. Clayton went bankrupt in 1933 and the magazine was sold to Street & Smith. The new editor was F. Orlin Tremaine, who soon made ''Astounding'' the leading magazine in the nascent pulp science fiction field, publishing well-regarded stories such as Jack Williamson's '' Legion of Space'' and John W. Campbell's "Twilight". At the end of 1937, Campbell took over editorial duties under Tremaine's supervision, and the following year Tremaine was let go, giving Campbell more independence. Over the next few years Campbell published many stories that became classics in the field, including Isaac Asimov's ''Foundation'' series, A. E. van Vogt's ''Slan'', and several novels and stories by Robert A. Heinle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ringworld
''Ringworld'' is a 1970 science fiction novel by Larry Niven, set in his Known Space universe and considered a classic of science fiction literature. ''Ringworld'' tells the story of Louis Wu and his companions on a mission to the Ringworld, a rotating wheel artificial world, an alien construct in space in diameter. Niven later added three sequel novels and then cowrote, with Edward M. Lerner, four prequels and a final sequel; the five latter novels constitute the Fleet of Worlds series. All the novels in the Ringworld series tie into numerous other books set in Known Space. ''Ringworld'' won the Nebula Award in 1970, as well as both the Hugo Award and Locus Award in 1971. Plot summary On planet Earth in 2850 AD, Louis Gridley Wu is celebrating his 200th birthday. Despite his age, Louis is in perfect physical condition due to the longevity drug boosterspice. He meets Nessus, a Pierson's puppeteer, who offers him a mysterious job. Intrigued, Louis eventually accepts. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Big Dumb Object
In discussion of science fiction, a Big Dumb Object (BDO) is any mysterious object, usually of extraterrestrial or unknown origin and immense power, in a story which generates an intense sense of wonder by its mere existence. To a certain extent, the term deliberately deflates this. The term was not in general use until Peter Nicholls included it in ''The Encyclopedia of Science Fiction'' as a joke in 1993, while its creation has been attributed to reviewer Roz Kaveney. Big Dumb Objects often exhibit extreme or unusual properties, or a total absence of some expected properties: * The monolith in Stanley Kubrick and Arthur C. Clarke's '' 2001: A Space Odyssey'' (foreshadowed in '' The Sentinel'') is an indecipherable influence on the protohumans to whom it first appears, and later in the film serves to show how little humans have evolved. Astronaut Bowman's attempt to interact with the monolith only makes him a part of its mystery. * In Arthur C. Clarke's novel ''Rendezvous w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dennis E
Dennis or Denis is a first or last name from the Greco-Roman name Dionysius, via one of the Christian saints named Dionysius. The name came from Dionysus, the Greek god of ecstatic states, particularly those produced by wine, which is sometimes said to be derived from the Greek Dios (Διός, "of Zeus") and Nysos or Nysa (Νῦσα), where the young god was raised. Dionysus (or Dionysos; also known as Bacchus in Roman mythology and associated with the Italic Liber), the Thracian god of wine, represents not only the intoxicating power of wine, but also its social and beneficent influences. He is viewed as the promoter of civilization, a lawgiver, and lover of peace—as well as the patron deity of both agriculture and the theater. Dionysus is a god of mystery religious rites, such as those practiced in honor of Demeter and Persephone at Eleusis near Athens. In the Thracian mysteries, he wears the "bassaris" or fox-skin, symbolizing new life. (See also Maenads.) A mediaeval ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diameter
In geometry, a diameter of a circle is any straight line segment that passes through the center of the circle and whose endpoints lie on the circle. It can also be defined as the longest chord of the circle. Both definitions are also valid for the diameter of a sphere. In more modern usage, the length d of a diameter is also called the diameter. In this sense one speaks of diameter rather than diameter (which refers to the line segment itself), because all diameters of a circle or sphere have the same length, this being twice the radius r. :d = 2r \qquad\text\qquad r = \frac. For a convex shape in the plane, the diameter is defined to be the largest distance that can be formed between two opposite parallel lines tangent to its boundary, and the is often defined to be the smallest such distance. Both quantities can be calculated efficiently using rotating calipers. For a curve of constant width such as the Reuleaux triangle, the width and diameter are the same because all ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Larry Niven
Laurence van Cott Niven (; born April 30, 1938) is an American science fiction writer. His best-known works are ''Ringworld'' (1970), which received Hugo, Locus, Ditmar, and Nebula awards, and, with Jerry Pournelle, ''The Mote in God's Eye'' (1974) and ''Lucifer's Hammer'' (1977). The Science Fiction and Fantasy Writers of America named him the 2015 recipient of the Damon Knight Memorial Grand Master Award. His work is primarily hard science fiction, using big science concepts and theoretical physics. It also often includes elements of detective fiction and adventure stories. His fantasy includes the series ''The Magic Goes Away'', rational fantasy dealing with magic as a non-renewable resource. Biography Niven was born in Los Angeles. He is a great-grandson of Edward L. Doheny, an oil tycoon who drilled the first successful well in the Los Angeles City Oil Field in 1892, and also was subsequently implicated in the Teapot Dome scandal. Niven briefly attended the Califor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Space Habitat
A space habitat (also called a space settlement, space colony, spacestead, space city, orbital habitat, orbital settlement, orbital colony, orbital stead or orbital city) is a more advanced form of living quarters than a space station or habitation module, in that it is intended as a permanent settlement or green habitat rather than as a simple way-station or other specialized facility. No space habitat has been constructed yet, but many design concepts, with varying degrees of realism, have come both from engineers and from science-fiction authors. The term ''space habitat'' sometimes includes more broadly habitats built on or in a body other than Earth—such as the Moon, Mars or an asteroid. This article concentrates on self-contained structures envisaged for micro-g environments. Definition A space habitat, or more precisely a space settlement, is any large-scale habitation facility in space, or more particularly in outer space or an orbit. A space habitat is typically de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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