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great circle
great circle A line on the surface of a sphere representing the circumference of a circle whose centre is coincident with the centre of that sphere. In making a stereographic projection, a horizontal (equatorial) projection of the sphere (i.e. as a plane at right angles to the N—S plane) is a primitive circle of given radius, and also a great circle. All other great circles are similar to lines of longitude. A line joining the points on the conceptual sphere at right angles to the horizontal plane will project on a stereogram as a straight line passing through the centre of the projection, with the N and S poles as its diameter, both of which plot coincidentally in the centre of the horizontal plane. See PLANE OF PROJECTION.
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AILSA ALLABY and MICHAEL ALLABY. "great circle." A Dictionary of Earth Sciences. 1999. Encyclopedia.com. 28 May. 2012 <http://www.encyclopedia.com>. AILSA ALLABY and MICHAEL ALLABY. "great circle." A Dictionary of Earth Sciences. 1999. Encyclopedia.com. (May 28, 2012). http://www.encyclopedia.com/doc/1O13-greatcircle.html AILSA ALLABY and MICHAEL ALLABY. "great circle." A Dictionary of Earth Sciences. 1999. Retrieved May 28, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O13-greatcircle.html |
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great circle
great circle, the largest circle which can be inscribed on the surface of a sphere. In terms of the earth, the equator, and all the meridians of longitude, since they pass through both poles, are great circles, i.e. the centres of all these circles lie at the centre of the earth. It follows therefore that any circle inscribed around the earth which has its centre at the centre of the earth is a great circle.
The shortest distance between any two points on the earth's surface lies along the great circle which passes through them both. Radio signals follow the path of great circles. See also gnomonic chart; mercator projection. |
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"great circle." The Oxford Companion to Ships and the Sea. 2006. Encyclopedia.com. 28 May. 2012 <http://www.encyclopedia.com>. "great circle." The Oxford Companion to Ships and the Sea. 2006. Encyclopedia.com. (May 28, 2012). http://www.encyclopedia.com/doc/1O225-greatcircle.html "great circle." The Oxford Companion to Ships and the Sea. 2006. Retrieved May 28, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O225-greatcircle.html |
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great circle
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"great circle." World Encyclopedia. 2005. Encyclopedia.com. 28 May. 2012 <http://www.encyclopedia.com>. "great circle." World Encyclopedia. 2005. Encyclopedia.com. (May 28, 2012). http://www.encyclopedia.com/doc/1O142-greatcircle.html "great circle." World Encyclopedia. 2005. Retrieved May 28, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O142-greatcircle.html |
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great circle
great circle A circle on a sphere whose plane passes through the sphere's centre. On the celestial sphere, the celestial equator, the ecliptic, and all lines of right ascension are great circles; lines of declination, other than the celestial equator, are small circles.
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Cite this article
"great circle." A Dictionary of Astronomy. 1997. Encyclopedia.com. 28 May. 2012 <http://www.encyclopedia.com>. "great circle." A Dictionary of Astronomy. 1997. Encyclopedia.com. (May 28, 2012). http://www.encyclopedia.com/doc/1O80-greatcircle.html "great circle." A Dictionary of Astronomy. 1997. Retrieved May 28, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O80-greatcircle.html |
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