Tuesday, September 16, 2008

wiki knowledge - SEPT 2008 [A] unordered

theme/topics centered primarily around EARTH/astronomy

WEIGHTED MEAN
The weighted mean is similar to an arithmetic mean (the most common type of average), where instead of each of the data points contributing equally to the final average, some data points contribute more than others. The notion of weighted mean plays a role in descriptive statistics and also occurs in a more general form in several other areas of mathematics.
If all the weights are equal, then the weighted mean is the same as the arithmetic mean. While weighted means generally behave in a similar fashion to arithmetic means, they do have a few counter-intuitive properties, as captured for instance in Simpson's paradox.
The term weighted average usually refers to a weighted arithmetic mean, but weighted versions of other means can also be calculated, such as the weighted geometric mean and the weighted harmonic mean.

LIGHT YEAR
A light-year or light year is a unit of length, equal to just under ten trillion kilometres. As defined by the International Astronomical Union (which is the body which has the jurisdictional authority to promulgate the definition), a light-year is the distance that light travels in a vacuum in one Julian year.
A light-year is equal to:
* exactly 9,460,730,472,580.8 km (about 10 Pm)
* about 5,878,625,373,183.61 international miles
* about 63,241 astronomical units
* about 0.3066 parsecs

GAMMA RAY
Gamma-ray bursts (GRBs) are the most luminous electromagnetic events occurring in the universe since the Big Bang. They are flashes of gamma rays emanating from seemingly random places in deep space at random times. The duration of a gamma-ray burst is typically a few seconds, but can range from a few milliseconds to several minutes, and the initial burst is usually followed by a longer-lived "afterglow" emitting at longer wavelengths (X-ray, ultraviolet, optical, infrared, and radio). Gamma-ray bursts are detected by orbiting satellites about two to three times per week, but the number of GRBs that could be observed from Earth is about three times this and is currently limited by the efficiency of the instruments.

NAKED EYE
The naked eye is a figure of speech referring to human visual perception that is unaided by enhancing equipment, such as a telescope or binocular. (It, therefore, does not exclude the use of smaller scale aids such as glasses.) The term is often used in astronomy when referring to events that can be viewed by the general public, such as astronomical conjunctions, passage of comets or meteor showers. Sky lore and various tests demonstrate an impressive wealth of phenomena that can be seen with the unaided eye.

UNCANNY VALLEY
The uncanny valley is a hypothesis that when robots and other facsimiles of humans look and act almost like actual humans, it causes a response of revulsion among human observers. The "valley" in question is a dip in a proposed graph of the positivity of human reaction as a function of a robot's lifelikeness. The phenomenon can be explained by the notion that, if an entity is sufficiently non-humanlike, then the humanlike characteristics will tend to stand out and be noticed easily, generating empathy. On the other hand, if the entity is "almost human", then the non-human characteristics will be the ones that stand out, leading to a feeling of "strangeness" in the human viewer. In other words, a robot stuck inside the uncanny valley is no longer being judged by the standards of a robot doing a good job at pretending to be human, but is instead being judged by the standards of a human doing a terrible job at acting like a normal person.

HOLOGRAHY
Holography is a technique that allows the light scattered from an object to be recorded and later reconstructed so that it appears as if the object is in the same position relative to the recording medium as it was when recorded. The image changes as the position and orientation of the viewing system changes in exactly the same way as if the object were still present, thus making the recorded image (hologram) appear three dimensional. Holograms can also be made using other types of waves.
The technique of holography can also be used to optically store, retrieve, and process information. While holography is commonly used to display static 3-D pictures, it is not yet possible to generate arbitrary scenes by a holographic volumetric display.

Digital holography is the technology of acquiring and processing holographic measurement data, typically via a CCD camera or a similar device. In particular, this includes the numerical reconstruction of object data from the recorded measurement data, in distinction to an optical reconstruction which reproduces an aspect of the object. Digital holography typically delivers three-dimensional surface or optical thickness data. There are different techniques available in practice, depending on the intended purpose.

MASDAR VALLEY
Masdar City is a future "green city" being constructed in The United Arab Emirates. It is a city which is designed to have no carbon emissions, cars, or waste. It will cost $22 billion (£11 billion) and take eight years to make. It will be able to hold a population of 50,000 people and 1,500 businesses. The city will cover 1,483 acres (6.00 km²).
The city will have a personal electrical power supply mainly from two renewable energy sources: wind turbines and solar panels. Water will be provided through a solar-powered desalination plant and air conditioning will be provided naturally from wind towers.
It is planned to save more than $2 billion in oil over the next 25 years along with creating more than 70 000 jobs.
No one has ever built a zero-carbon city before. Nor one producing zero waste or fully powered by renewable energy. Masdar City will accomplish all three,” said Sultan Al Jaber.The city was designed by Foster and Partners, a British company.

BLOOD AND HONOUR
Blood & Honour is a neo-Nazi music promotion network, founded in 1987, that is comprised of white power skinheads and other white nationalists. The group organizes white power concerts by Rock Against Communism (RAC) bands and distributes a magazine of the same name. Ian Stuart Donaldson, singer of the band Skrewdriver, was the founder and one of the prominent leaders until his death in 1993. Blood & Honour took its name from the motto of the Hitler Youth, Blut und Ehre. Sometimes the code 28 stands for Blood & Honour, derived from the second and eighth letters of the Latin alphabet, B and H.
Blood & Honour accepts bands with neo-Nazi, white nationalist or white power views. There are official divisions in several different countries around the world.

OORT CLOUD
The Oort cloud is a hypothetical spherical cloud of comets believed to lie roughly 50,000 AU, or nearly a light-year, from the Sun. This distance places the cloud at nearly a quarter of the distance to Proxima Centauri, the nearest star to the Sun. The Kuiper belt and scattered disc, the other two known reservoirs of trans-Neptunian objects, are less than one thousandth the Oort cloud's distance. The outer extent of the Oort cloud defines the boundary of our Solar System.
The Oort cloud is thought to comprise two separate regions: a spherical outer Oort cloud and a disc-shaped inner Oort cloud, or Hills cloud. Objects in the Oort cloud are largely composed of ices such as water, ammonia and methane. Astronomers believe that the matter comprising the Oort cloud formed closer to the Sun, and was scattered far out into space by the gravitational effects of the giant planets early in the Solar System's evolution.

MIND UPLOADING
In transhumanism and science fiction, mind uploading (also occasionally referred to by other terms such as mind transfer, whole brain emulation, or whole body emulation) refers to the hypothetical transfer of a human mind to an artificial substrate, such as a detailed computer simulation of an individual human brain.

UTOPIA
Utopia is a name for an ideal community, taken from the title of a book written in 1516 by Sir Thomas More describing a fictional island in the Atlantic Ocean, possessing a seemingly perfect socio-politico-legal system. The term has been used to describe both intentional communities that attempted to create an ideal society, and fictional societies portrayed in literature. "Utopia" is sometimes used pejoratively, in reference to an unrealistic ideal that is impossible to achieve, and has spawned other concepts, most prominently dystopia.
The word comes from Greek:
οὐ, "not", and τόπος, "place", indicating that More was utilizing the concept as allegory and did not consider such an ideal place to be realistically possible. It is worth noting that the homophone Eutopia, derived from the Greek εὖ, "good" or "well", and τόπος, "place", signifies a double meaning that was almost certainly intended. Despite this, most modern usage of the term "Utopia" assumes the latter meaning, that of a place of perfection rather than nonexistence. It is a nostalgic question, whether or not utopia exists.

DYSTOPIA
A dystopia (from the Greek δυσ- and τόπος, alternatively, cacotopia, kakotopia, cackotopia, or anti-utopia) is the vision of a society that is the opposite of utopia. A dystopian society is a state in which the conditions of life are miserable, characterized by human misery, poverty, oppression, violence, disease, and/or pollution.

MILITARY ANTI-FASCISM
Militant anti-fascism is a form of anti-fascism that advocates the use of violence against fascism. Within the anti-fascist movement, the term militant anti-fascism is often used in contrast to liberal anti-fascism.
Fascists often use violence and depend on a physical presence in the streets, and militant anti-fascists believe that an equal counterweight is essential to stop fascism. While European liberal anti-fascists either call on the state to censor what they call hate speech or prosecute fascists under existing laws, militant anti-fascists either oppose such calls or put no energy into heeding them. In contrast, militant anti-fascists believe that fascism should be tackled by communities rather than by the state.Militant anti-fascists are usually supporters of class struggle, and view fascism as an anti-working class political system. Militant anti-fascists tend to promote radical anti-capitalist transformation of society, rather than defending the status quo of liberal democracy. This often translates into support for some form of socialism, communism, or anarchism.

SPECIATION
Speciation is the evolutionary process by which new biological species arise. There are four modes of natural speciation, based on the extent to which speciating populations are geographically isolated from one another: allopatric, peripatric, parapatric, and sympatric. Speciation may also be induced artificially, through animal husbandry or laboratory experiments. Observed examples of each kind of speciation are provided throughout.

TRILOBITE
Trilobites ("three-lobes") are extinct arthropods that form the class Trilobita. They appeared in the Early Cambrian period and flourished throughout the lower Paleozoic era before beginning a drawn-out decline to extinction when, during the Late Devonian extinction, all trilobite orders, with the sole exception of Proetida, died out. The last of the trilobites disappeared in the mass extinction at the end of the Permian about 250 million years ago (m.y.a.).
Trilobites are very well-known, and possibly the second-most famous fossil group, after the dinosaurs. When trilobites appear in the fossil record of the Lower Cambrian they are already highly diverse and geographically dispersed. Because of their diversity and an easily fossilized exoskeleton, they left an extensive fossil record with some 17,000 known species spanning Paleozoic time. Trilobites have been important in biostratigraphy, paleontology, and plate tectonics research. For example, trilobites have been important in estimating the rate of speciation during the period known as the Cambrian Explosion because they are the most diverse group of metazoans known from the fossil record of the early Cambrian, and are readily distinguishable because of complex and well preserved morphologies. The trilobites are often placed within the arthropod subphylum Schizoramia within the superclass Arachnomorpha (equivalent to the Arachnata), although several alternative taxonomies are found in the literature.

POSTHUMAN
A posthuman or post-human is, according to the transhumanist intellectuals, a hypothetical future being "whose basic capacities so radically exceed those of present humans as to be no longer unambiguously human by our current standards.
The difference between the posthuman and other hypothetical sophisticated non-humans is that a posthuman was once a human, either in its lifetime or in the lifetimes of some or all of its direct ancestors. As such, a prerequisite for a posthuman is a transhuman, the point at which the human being begins surpassing his or her own limitations, but is still recognisable as a human person or similar.

FM-2030
FM-2030 (October 15, 1930 – July 8, 2000) was a transhumanist philosopher and futurist. FM-2030 was born Fereidoun M. Esfandiary (Persian: فریدون اسفندیاری). He became notable as a transhumanist with the book "Are You a Transhuman?: Monitoring and Stimulating Your Personal Rate of Growth in a Rapidly Changing World", published in 1989. In addition he wrote a number of works of fiction under his original name F.M. Esfandiary. The son of an Iranian diplomat, he traveled widely as a child, living in 17 countries by age 11; then, as a young man, he represented Iran in the 1948 Olympic Games and served on the United Nations Conciliation Commission for Palestine from 1952 to 1954. On July 8, 2000, FM-2030 died from pancreatic cancer and was placed in cryonic suspension at the Alcor Life Extension Foundation in Scottsdale, Arizona, where his body remains today.
F.M. Esfandiary changed his name to FM-2030 for two main reasons. Firstly, to reflect the hope and belief that he would live to celebrate his 100th birthday in 2030; Secondly, and more importantly, to break free of the widespread practice of naming conventions that are rooted in a collectivist mentality, and exist only as a relic of humankind's tribalistic past. Traditional names almost always stamp a label of collective identity - varying from gender, to nationality - on the individual, thereby existing as prima facie elements of thought processes in the human cultural fabric, that tend to degenerate into stereotyping, factionalism, and discrimination. In his own words, "Conventional names define a person's past: ancestry, ethnicity, nationality, religion. I am not who I was ten years ago and certainly not who I will be in twenty years. The name 2030 reflects my conviction that the years around 2030 will be a magical time. In 2030 we will be ageless and everyone will have an excellent chance to live forever. 2030 is a dream and a goal."
Many of FM-2030's predictions about social trends from the 1970s through the early 21st century proved remarkably prescient. FM-2030 argued that the inherent dynamic of the modern globalizing civilization would bring such changes about despite the best efforts of conservative elites to enforce traditional beliefs. FM-2030 once said, "I am a 21st century person who was accidentally launched in the 20th. I have a deep nostalgia for the future.

SUPERNOVA
A supernova (plural: supernovae or supernovas) is a stellar explosion. They are extremely luminous and cause a burst of radiation that often briefly outshines an entire galaxy before fading from view over several weeks or months. During this short interval, a supernova can radiate as much energy as the Sun could emit over its life span. The explosion expels much or all of a star's material at a velocity of up to a tenth the speed of light, driving a shock wave into the surrounding interstellar medium. This shock wave sweeps up an expanding shell of gas and dust called a supernova remnant.

COGNITION
The term cognition is used in different ways by different disciplines. In psychology, it refers to an information processing view of an individual's psychological functions. Other interpretations of the meaning of cognition link it to the development of concepts; individual minds, groups, organizations, and even larger coalitions of entities, can be modelled as societies which cooperate to form concepts. The autonomous elements of each 'society' would have the opportunity to demonstrate emergent behavior in the face of some crisis or opportunity. Cognition can also be interpreted as "understanding and trying to make sense of the world".

SALVADOR DALI
Salvador Domingo Felipe Jacinto Dalí i Domènech, 1st Marquis of Púbol (May 11, 1904 – January 23, 1989), was a Spanish Catalan surrealist painter born in Figueres, Catalonia, Spain. Dalí was a skilled draftsman, best known for the striking and bizarre images in his surrealist work. His painterly skills are often attributed to the influence of Renaissance masters. His best known work, The Persistence of Memory, was completed in 1931. Salvador Dalí's artistic repertoire also included film, sculpture, and photography. He collaborated with Walt Disney on the unfinished Academy Award-nominated short cartoon Destino, which was completed and released posthumously in 2003.
Widely considered to be greatly imaginative, Dalí had an affinity for doing unusual things to draw attention to himself. This sometimes irked those who loved his art as much as it annoyed his critics, since his eccentric manner sometimes drew more public attention than his artwork. The purposefully-sought notoriety led to broad public recognition and many purchases of his works by people from all walks of life.

ATMOSPHERE
An atmosphere (from Greek ατμός - atmos, "vapor" + σφαίρα - sphaira, "sphere") is a layer of gases that may surround a material body of sufficient mass, by the gravity of the body, and are retained for a longer duration if gravity is high and the atmosphere's temperature is low. Some planets consist mainly of various gases, and therefore have very deep atmospheres (gas giants).
The term stellar atmosphere is used for the outer region of a star, and typically includes the portion starting from the opaque photosphere outwards. Relatively low-temperature stars may form compound molecules in their outer atmosphere. Earth's atmosphere, which contains oxygen used by most organisms for respiration and carbon dioxide used by plants, algae and cyanobacteria for photosynthesis, also protects living organisms from genetic damage by solar ultraviolet radiation. Its current composition is the product of billions of years of biochemical modification of the paleoatmosphere by living organisms.

BIOSPHERE
The biosphere is the part of the Earth, including air, land, surface rocks, and water, within which life occurs, and which biotic processes in turn modify or transform. From the broadest biophysiological point of view, the biosphere is the global ecological system integrating all living beings and their relationships, including their interaction with the elements of the lithosphere, hydrosphere, and atmosphere. This biosphere is postulated to have evolved, beginning through a process of biogenesis or biopoesis, at least some 3.5 billion years ago. Biomass accounts for about 3.7 kg carbon per square meter of the earth's surface averaged over land and sea, making a total of about 1900 gigatonnes of carbon.

NITROGEN OXIDE
The term nitrogen oxide typically refers to any binary compound of oxygen and nitrogen, or to a mixture of such compounds:
* Nitric oxide (NO), nitrogen(II) oxide
* Nitrogen dioxide (NO2), nitrogen(IV) oxide
* Nitrous oxide (N2O), nitrogen (I) oxide
* Dinitrogen trioxide (N2O3), nitrogen(II, IV) oxide
* Dinitrogen tetroxide (N2O4), nitrogen(IV) oxide
* Dinitrogen pentoxide (N2O5), nitrogen(V) oxide
(Note that the last three are unstable.)
Chemical reactions that produce nitrogen oxides often produce several different compounds, the proportions of which depend on the specific reaction and conditions. For this reason, secondary production of N2O is undesirable, as NO and NO2 — which are extremely toxic — are liable to be produced as well.

EXTINCTION EVENT
An extinction event (also known as: mass extinction; extinction-level event, ELE) is a sharp decrease in the number of species in a relatively short period of time. Mass extinctions affect most major taxonomic groups present at the time — birds, mammals, reptiles, amphibians, fish, invertebrates and other simpler life forms. They may be caused by one or both of:
* extinction of an unusually large number of species in a short period.
* a sharp drop in the rate of speciation.
Over 99% of species that ever lived are now extinct, but extinction occurs at an uneven rate. Based on the fossil record, the background rate of extinctions on Earth is about two to five taxonomic families of marine invertebrates and vertebrates every million years. Marine fossils are mostly used to measure extinction rates because they are more plentiful and cover a longer time span than fossils of land organisms.

THIS maybe a weekly thingie...

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