Left alone, Light will travel in straight lines. Even though lenses can bend light and mirrors
can deflect it, light still travels in a straight line between optical
devices. This works fine for most purposes, with cameras, binoculars, telescopes,
etc., but there are Times when people want to look around corners or probe inside places that are not
in a straight line to their eyes.
The problem of how to pipe (see Specifications - Piping) light arose long before the solution. In 1880, Concord, Massachusetts
engineer (see Engineer - You Might Be One If ... ), William Wheeler, patented a scheme for piping light through buildings.
Why? He did not think the Edison, Thomas Incandescent light bulb would prove practical, so he planned on using light from a bright
electric arc to illuminate distant rooms. He received a patent for his
concept, which basically relied on pipes as we would run plumbing today.