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Kármán Line
The Kármán line (or von Kármán line ) is an attempt to define a boundary between Earth's atmosphere and outer space, and offers a specific definition set by the Fédération aéronautique internationale (FAI), an international record-keeping body for aeronautics. Defining the edge of space is important for legal and regulatory purposes since aircraft and spacecraft fall under different jurisdictions and are subject to different treaties. International law does not define the edge of space, or the limit of national airspace. The FAI defines the Kármán line as space beginning above Earth's mean sea level. This number is well above the altitude reachable by a conventional airplane and is roughly where satellites, even on very eccentric trajectories, will decay before completing a single orbit. While experts disagree on exactly where the atmosphere ends and space begins, most regulatory agencies (including the United Nations) accept the FAI Kármán line definition or some ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atmosphere Layers
An atmosphere () is a layer of gas or layers of gases that envelop a planet, and is held in place by the gravity of the planetary body. A planet retains an atmosphere when the gravity is great and the temperature of the atmosphere is low. A stellar atmosphere is the outer region of a star, which includes the layers above the opaque photosphere; stars of low temperature might have outer atmospheres containing compound molecules. The atmosphere of Earth is composed of nitrogen (78%), oxygen (21%), argon (0.9%), carbon dioxide (0.04%) and trace gases. Most organisms use oxygen for respiration; lightning and bacteria perform nitrogen fixation to produce ammonia that is used to make nucleotides and amino acids; plants, algae, and cyanobacteria use carbon dioxide for photosynthesis. The layered composition of the atmosphere minimises the harmful effects of sunlight, ultraviolet radiation, the solar wind, and cosmic rays to protect organisms from genetic damage. The current composi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astronautics
Astronautics (or cosmonautics) is the theory and practice of travel beyond Earth's atmosphere into outer space. Spaceflight is one of its main applications and space science its overarching field. The term ''astronautics'' (originally ''astronautique'' in French) was coined in the 1920s by J.-H. Rosny, president of the Goncourt academy, in analogy with aeronautics. Because there is a degree of technical overlap between the two fields, the term aerospace is often used to describe both at once. In 1930, Robert Esnault-Pelterie published the first book on the new research field. The term ''cosmonautics'' (originally ''cosmonautique'' in French) was introduced in 1930s by Ary Sternfeld with his book ''Initiation à la Cosmonautique'' (Introduction to cosmonautics) (the book brought him the Prix REP-Hirsch, later known as the Prix d'Astronautique, of the French Astronomical Society in 1934.) As with aeronautics, the restrictions of mass, temperatures, and external forces require ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bell X-2
The Bell X-2 (nicknamed "Starbuster") was an X-plane research aircraft built to investigate flight characteristics in the Mach 2–3 range. The X-2 was a rocket-powered, swept-wing research aircraft developed jointly in 1945 by Bell Aircraft Corporation, the United States Air Force and the National Advisory Committee for Aeronautics (NACA) to explore aerodynamic problems of supersonic flight and to expand the speed and altitude regimes obtained with the earlier X-1 series of research aircraft. Design and development The Bell X-2 was developed to provide a vehicle for researching flight characteristics at speeds and altitudes in excess of the capabilities of the Bell X-1 and D-558 II, while investigating aerodynamic heating problems in what was then called the "thermal thicket". The Bell X-2 had a prolonged development period due to the advances needed in aerodynamic design, control systems, materials that retained adequate mechanical properties at high temperature, and other ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iven Carl Kincheloe Jr
Iven Carl "Kinch" Kincheloe Jr. (July 2, 1928 – July 26, 1958) was an American pilot. He served in the U.S. Air Force during the Korean War, in which he was recognized as a flying ace. He continued as a test pilot after the war, participating in the Bell X-2 program, in which he set an altitude record of in 1956. For this suborbital flight above most of the atmosphere, he became known as "The First Spaceman". He was selected for the Air Force's program to put a man in space, but was killed in a plane crash in 1958. Early life and education Born July 2, 1928, in Detroit, Michigan, Kincheloe grew up in Cassopolis in the southwest part of the state, the only child of Iven C. Kincheloe Sr. (1894–1966) and Frances Wilder Kincheloe. Interested in aviation from a very young age, he graduated from Dowagiac High School in 1945 and attended Purdue University in West Lafayette, Indiana. Kincheloe joined the Reserve Officers' Training Corps (ROTC), was a member of Sigma Phi Epsilon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Airspace
Airspace is the portion of the atmosphere controlled by a country above its territory, including its territorial waters or, more generally, any specific three-dimensional portion of the atmosphere. It is not the same as aerospace, which is the general term for Earth's atmosphere and the outer space in its vicinity. Within the United States: * Controlled airspace exists where it is deemed necessary that air traffic control has some form of positive executive control over aircraft flying in that airspace (however, air traffic control does not necessarily control traffic operating under visual flight rules (VFR) within this airspace). Airspace may be further subdivided into a variety of areas and zones, including those where there are either restrictions on flying activities or complete prohibition of flying activities. Horizontal boundary By international law, a state "has complete and exclusive sovereignty over the airspace above its territory", which corresponds with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tide
Tides are the rise and fall of sea levels caused by the combined effects of the gravitational forces exerted by the Moon (and to a much lesser extent, the Sun) and are also caused by the Earth and Moon orbiting one another. Tide tables can be used for any given locale to find the predicted times and amplitude (or " tidal range"). The predictions are influenced by many factors including the alignment of the Sun and Moon, the phase and amplitude of the tide (pattern of tides in the deep ocean), the amphidromic systems of the oceans, and the shape of the coastline and near-shore bathymetry (see '' Timing''). They are however only predictions, the actual time and height of the tide is affected by wind and atmospheric pressure. Many shorelines experience semi-diurnal tides—two nearly equal high and low tides each day. Other locations have a diurnal tide—one high and low tide each day. A "mixed tide"—two uneven magnitude tides a day—is a third regular category. Tid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meander
A meander is one of a series of regular sinuous curves in the channel of a river or other watercourse. It is produced as a watercourse erodes the sediments of an outer, concave bank ( cut bank) and deposits sediments on an inner, convex bank which is typically a point bar. The result of this coupled erosion and sedimentation is the formation of a sinuous course as the channel migrates back and forth across the axis of a floodplain. The zone within which a meandering stream periodically shifts its channel is known as a meander belt. It typically ranges from 15 to 18 times the width of the channel. Over time, meanders migrate downstream, sometimes in such a short time as to create civil engineering challenges for local municipalities attempting to maintain stable roads and bridges.Neuendorf, K.K.E., J.P. Mehl Jr., and J.A. Jackson, J.A., eds. (2005) ''Glossary of Geology'' (5th ed.). Alexandria, Virginia, American Geological Institute. 779 pp. Charlton, R., 2007. ''Fundamen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mean Sea Level
There are several kinds of mean in mathematics, especially in statistics. Each mean serves to summarize a given group of data, often to better understand the overall value (magnitude and sign) of a given data set. For a data set, the '' arithmetic mean'', also known as "arithmetic average", is a measure of central tendency of a finite set of numbers: specifically, the sum of the values divided by the number of values. The arithmetic mean of a set of numbers ''x''1, ''x''2, ..., x''n'' is typically denoted using an overhead bar, \bar. If the data set were based on a series of observations obtained by sampling from a statistical population, the arithmetic mean is the ''sample mean'' (\bar) to distinguish it from the mean, or expected value, of the underlying distribution, the ''population mean'' (denoted \mu or \mu_x).Underhill, L.G.; Bradfield d. (1998) ''Introstat'', Juta and Company Ltd.p. 181/ref> Outside probability and statistics, a wide range of other notions of mean ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Median
In statistics and probability theory, the median is the value separating the higher half from the lower half of a data sample, a population, or a probability distribution. For a data set, it may be thought of as "the middle" value. The basic feature of the median in describing data compared to the mean (often simply described as the "average") is that it is not skewed by a small proportion of extremely large or small values, and therefore provides a better representation of a "typical" value. Median income, for example, may be a better way to suggest what a "typical" income is, because income distribution can be very skewed. The median is of central importance in robust statistics, as it is the most resistant statistic, having a breakdown point of 50%: so long as no more than half the data are contaminated, the median is not an arbitrarily large or small result. Finite data set of numbers The median of a finite list of numbers is the "middle" number, when those numbers are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mean
There are several kinds of mean in mathematics, especially in statistics. Each mean serves to summarize a given group of data, often to better understand the overall value (magnitude and sign) of a given data set. For a data set, the '' arithmetic mean'', also known as "arithmetic average", is a measure of central tendency of a finite set of numbers: specifically, the sum of the values divided by the number of values. The arithmetic mean of a set of numbers ''x''1, ''x''2, ..., x''n'' is typically denoted using an overhead bar, \bar. If the data set were based on a series of observations obtained by sampling from a statistical population, the arithmetic mean is the ''sample mean'' (\bar) to distinguish it from the mean, or expected value, of the underlying distribution, the ''population mean'' (denoted \mu or \mu_x).Underhill, L.G.; Bradfield d. (1998) ''Introstat'', Juta and Company Ltd.p. 181/ref> Outside probability and statistics, a wide range of other notions of mean ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sovereignty
Sovereignty is the defining authority within individual consciousness, social construct, or territory. Sovereignty entails hierarchy within the state, as well as external autonomy for states. In any state, sovereignty is assigned to the person, body, or institution that has the ultimate authority over other people in order to establish a law or change an existing law. In political theory, sovereignty is a substantive term designating supreme legitimate authority over some polity. In international law, sovereignty is the exercise of power by a state. ''De jure'' sovereignty refers to the legal right to do so; ''de facto'' sovereignty refers to the factual ability to do so. This can become an issue of special concern upon the failure of the usual expectation that ''de jure'' and ''de facto'' sovereignty exist at the place and time of concern, and reside within the same organization. Etymology The term arises from the unattested Vulgar Latin's ''*superanus'', (itself derived ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Appleton-Century-Crofts
Appleton-Century-Crofts, Inc. was a division of the Meredith Publishing Company. It is a result of the merger of Appleton-Century Company with F.S. Crofts Co. in 1948. Prior to that The Century Company had merged with D. Appleton & Company in 1933. The Century Company and its subsequent incarnations published the '' New Century Dictionary''. Eventually Meredith sold the majority of the company and the Appleton name to Prentice-Hall in 1973. Part of the company became part of Hawthorn Books and New Win Publishing. Timeline * 1948 Appleton-Century Company, founded in 1933, merged with F. S. Crofts Co., founded in 1924, to form Appleton-Century-Crofts. * 1960 Purchased by Meredith Publishing Company * 1969 Meredith trade books division sold to Hawthorn Books * 1973 Appleton textbook division purchased by Prentice Hall; the medical division retains the Appleton name * 1974 New Century division sold to Charles Walther, and was later renamed New Win Publishing * 1998 Prentice H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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