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:
“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)
“Wise child, didst hastily return
And mad’st thy mother’s womb thine urn.
How summed a circle didst thou leave mankind
Of deepest lore, could we the center find!”
—Ben Jonson (1572–1637)
“Prayer is the fair and radiant daughter of all the human virtues, the arch connecting heaven and earth, the sweet companion that is alike the lion and the dove; and prayer will give you the key of heaven. As pure and as bold as innocence, as strong as all things are that are entire and single, this fair and invincible queen rests on the material world; she has taken possession of it; for, like the sun, she casts about it a sphere of light.”
—Honoré De Balzac (1799–1850)