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:
“A man should not go where he cannot carry his whole sphere or society with him,Mnot bodily, the whole circle of his friends, but atmospherically. He should preserve in a new company the same attitude of mind and reality of relation, which his daily associates draw him to, else he is shorn of his best beams, and will be an orphan in the merriest club.”
—Ralph Waldo Emerson (1803–1882)
“They will mark the stone-battlements
And the circle of them
With a bright stain.
They will cast out the dead
A sight for Priam’s queen to lament
And her frightened daughters.”
—Hilda Doolittle (1886–1961)
“O sun,
Burn the great sphere thou mov’st in! darkling stand
The varying shore o’ th’ world!”
—William Shakespeare (1564–1616)