Circle of a sphere Circle of a sphere A circle of a sphere is a circle that lies on a sphere. Such a circle can be formed as the intersection of a sphere and a plane, or of two spheres. A circle on a sphere whose plane passes through the center of the sphere is called a great circle; otherwise it is a small circle. Circles of a sphere have radius less than or equal to the sphere radius, 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
Line Describing a Cone allowed him to actualize his ideas on the relationship between viewer and film and the medium of film itself. The thirty-minute film begins with a single white dot projected onto a black surface. As time progresses, the dot begins to form a curved line, tracing the circumference of a circle until the end of the line reaches its starting point. Meanwhile, particles in the air reveal the path of light in the space between the projector and the wall, making visible a cone of light. If the artist's display specifications are met, this beam of light projects between thirty and