A circle of a sphere is a circle defined as the intersection of a sphere and a plane. If the plane contains the center of the sphere then the circle is called a great circle, otherwise it is a small circle. Circles of a sphere have radius less than or equal to the radius sphere, with equality when the circle is a great circle.
In the geographic coordinate system on a globe, the parallels of latitude are such circles, with the Equator the only great circle. By contrast, all meridians of longitude, paired with their opposite meridian in the other hemisphere, form great circles.
The diameter of the sphere which passes though the center of the circle is called its axis and the endpoints of this diameter are called its poles. A circle of a sphere can also be defined as the set of points at a given angular distance from a given pole.
Read more about Circle Of A Sphere: Geometric Proof
Famous quotes containing the words circle of, circle and/or sphere:
“Writing about an idea frees me of it. Thinking about it is a circle of repetitions.”
—Mason Cooley (b. 1927)
“The passion of love is essentially selfish, while motherhood widens the circle of our feelings.”
—Honoré De Balzac (1799–1850)
“Every person is responsible for all the good within the scope of his abilities, and for no more, and none can tell whose sphere is the largest.”
—Gail Hamilton (1833–1896)