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ParabolaIn mathematics, the parabola is a conic section, the intersection of a right circular conical surface and a plane parallel to a generating straight line of that surface.... with the summation of an infinite series Series (mathematics) ...
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Parabola vs. sphere If cross-sections of a spherical surface and a parabolic surface were made by slicing each surface in half, these would be the shapes you would see. Parallax ...
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Parabola - A geometric curve followed by a body that moves with a speed exactly equal to escape velocityParallax - The shift in the direction of a star caused by the change in the position of the Earth as it moves about the Sun ...
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parabola: a mathematical term for the conic section obtained by cutting a cone with a plane parallel to its generator (or "edge").
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parabolaA conic section formed by cutting a circular cone at an angle parallel to one of the sides of the cone. paradigm ...
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gives a parabola, with a any number. Usually (though not always) y is isolated, so that the formula has the form y = f(x) ...
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Sphere versus Parabola. Most radio telescopes use a parabolic antenna to focus the energy received to a single point. The antenna is then pointed at the object of interest using a flexible mount.
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parabola An open curve all points of which are equidistant from a fixed point, called the focus , and a straight line. See conic section. The limiting case occurs when the point is on the line, in which case the parabola becomes a straight line.
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Imagine an inverted parabola with its minimum value at = 0; the configuration of the field can be represented as the position of a ball rolling on this curve. In the stable configuration it nestles in the bottom of the potential well at = 0.
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Finally, 341 are listed as having parabolic orbits, but this is rather fallacious because either it has not been possible to detect unequivocal deviations from a parabola on the (sometimes very short) arc along which the comets have been observed or, ...
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The mirrors are usually a section of a rotated parabola. High energy particle telescopes detect a flux of particles, usually originating at an astronomical source. History ...
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Applying Newton's method, he presupposed a parabola as an approximation for each orbit. Among the 24 parabolas, 3 were identical in size and superimposed in space.
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The orbits of comets are very elongated; some are long ellipses, some are nearly parabolic (see parabola), and some may be hyperbolic.
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He understood the parabola, both in terms of conic sections and in terms of the ordinate (y) varying as the square of the abscissa (x).
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Another system which forms real images consists of a set of two orthogonal parabolas of translation, off which incident X-rays reflect successively, as first proposed in 1948 by Kirkpatrick and Baez.
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The sun is a small target for a meteorite coming from infinity to hit, and if this considerable quantity reaches its mark, a much greater amount will circulate round the sun in parabolas, ...
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The orbit of such a body will be a parabola with the Sun as its focus. As the comet gets closer to the Sun its velocity increases reaching a maximum at its closest point whereupon is starts its journey back out to the outer reaches of the solar ...
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After rough Foucault measurements on 10%, 70% and 90% zones indicated that the mirror may be close to parabola, I assembled the optical tube outside (altitide bearings were not ready at that time yet) and took a look at Polaris.
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Lord Rosse then used a steam-driven machine to grind the mirror to the necessary shape, that of a parabola, which brings the light reflecting off the mirror to a focus further up within the telescope tube.
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0 = a perfect circle; any figure between 0 and 1 = an ellipse; 1 = a parabola; any figure greater than 1 = a hyperbola. Eccentricity may sometimes be expressed as a percentage.
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In 1681, the Saxon pastor Georg Samuel Doerfel set forth his proofs that comets are heavenly bodies moving in parabolas of which the sun is the focus.
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He is also well known for inventing the method of solving cubic equations by intercepting a parabola with a circle. Omar Khayyam the Writer and Poet ...
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Comets, however, have very large eccentricities, often approaching one, the value for a parabola. Such highly eccentric orbits are just as possible as circular orbits, as far as the laws of motion are concerned.
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Converging reflectors always have concave surfaces. The section shape is the arc of a circle in simple cases; the arc of a parabola is needed for more precise work. As these mirrors have positive power, they are sometimes called positive mirrors.
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See also: Time, Orbit, Distance, Solar, Earth
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