Question

The method of construction of kaleidoscope

Answer 1

Kaleidoscope

The kaleidoscope makes magic with light and mirrors. It may be considered a child's toy (or a toy for all ages), but it is also a simple optical device with technical applications for designers and pattern-makers. Greek words are the source of the name; it comes from kalos, eidos, and skopios meaning beautiful, form, and view, respectively.

Background

The body of the kaleidoscope has two main parts, the viewing tube (with an eyepiece at one end) and the object box or case at the opposite end of the tube. The object box is a thin, flat box made of two glass disks and a band circling the edges and holding the disks and the objects enclosed. Those objects are fragments of colored glass, beads, tinsel, or other reflective materials.

The outer disk of the object box is ground so it diffuses the incoming light; that is, it acts like a screen. The viewing tube has a glass eyepiece at one end; it may be ordinary glass or an optical lense with magnifying properties. Inside the tube, three strips of mirrors are joined to form a triangle; the angles of the mirrors also affects the view through the kaleidoscope. Typically, they are angled at either 45° or 60°. When the object box is turned or tapped, the glass or objects inside move and tumble freely. As the viewer looks through the eyepiece toward a light source, the mirrors produce symmetrical order out of the tumbling objects and multiply them six, eight, or more times depending on the angles of the mirrors.

A variation of the kaleidoscope—the teleidoscope—replaces the object box with another lens that allows the viewer to look at a distant object and view it in multiples. Still other variations use more mirrors. Two mirrors have the advantage of producing a centered pattern; multiple mirrors split and duplicate the image many times over. The kaleidoscope is infinitely entertaining because the patterns and combinations are endless and are not permanent unless photographed.

History

Although the ancient Greeks, including the mathematician Ptolemy, had contemplated the effects of abutting multiple mirrors, the kaleidoscope is the creation of one man. David Brewster (1781-1868) was born in Scotland and educated to become a minister at the University of Edinburgh. University studies exposed him to the wonders of science, however, and he abandoned the church in favor of studying the properties of light. He became an expert in polarization of light (the linear and planar properties of light), reflection of light using metal, and light absorption. For his scientific discoveries, Brewster was elected a fellow of the Royal Society (Britain's leading scientific organization) in 1815 and knighted in 1831.

Brewster invented and patented the kaleidoscope in 1816. He described its structure and operations in a 174-page scientific paper titled Treatise on the Kaleidoscope. In his treatise, Brewster calculated that 24 fragments of glass in the object box of a kaleidoscope could create more than 1.4 x 1033 fleeting views. He also described the most effective combinations of colors for kaleidoscopes based on light properties. In the 1840s, he used two lenses to produce a three-dimensional effect in creating the stereoscope. He was also a leading advocate of the flat Fresnel lens adopted by the British for lighthouses and was credited with saving thousands of lives by protecting vessels against shipwrecks. Brewster taught at the University of Edinburgh and the University of St. Andrews in Scotland, was one of the first editors of the Encyclopedia Britannica, and published many books and scientific papers.