Final answer:
A domed ceiling creates an open space by eliminating the interior angle at the edge where the wall meets the ceiling, similar to a concave mirror in physics, which converges light rays parallel to its axis.
Step-by-step explanation:
The concave surface forming part of a ceiling at its edge to eliminate the usual interior angle between the wall and the ceiling is often referred to as a dome. This architectural element can create an illusion of a larger and more open space, and it usually has an aesthetic function as well as an acoustic one in certain buildings. In physics, a similar concept applies to converging mirrors, specifically the concave mirror, which is a spherical mirror with its reflecting surface on the inner side of the sphere. This type of mirror is designed so that light rays that strike it parallel to its axis will converge at one or more points along the axis. The formation of images by this kind of mirror can be real, which can be projected onto a surface, or virtual, which appears to be behind the mirror depending on the position of the object with respect to the mirror's focal point.