|
Kaleidoscope
A kaleidoscope () is an optical instrument with two or more reflecting surfaces (or mirrors) tilted to each other at an angle, so that one or more (parts of) objects on one end of these mirrors are shown as a symmetrical pattern when viewed from the other end, due to repeated reflection. These reflectors are usually enclosed in a tube, often containing on one end a cell with loose, colored pieces of glass or other transparent (and/or opaque) materials to be reflected into the viewed pattern. Rotation of the cell causes motion of the materials, resulting in an ever-changing view being presented. Etymology The term "kaleidoscope" was coined by its Scottish inventor David Brewster. It is derived from the Ancient Greek word (), "beautiful, beauty", (), "that which is seen: form, shape" and (), "to look to, to examine", hence "observation of beautiful forms". It was first published in the patent that was granted on July 10, 1817. History Multiple reflection by two or more r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
David Brewster
Sir David Brewster Knight of the Royal Guelphic Order, KH President of the Royal Society of Edinburgh, PRSE Fellow of the Royal Society of London, FRS Fellow of the Society of Antiquaries of Scotland, FSA Scot Fellow of the Scottish Society of Arts, FSSA Member of the Institution of Civil Engineers, MICE (11 December 178110 February 1868) was a British scientist, inventor, author, and academic administrator. In science he is principally remembered for his experimental work in physical optics, mostly concerned with the study of the Polarization (waves), polarization of light and including the discovery of Brewster's angle. He studied the birefringence of crystals under compression and discovered photoelasticity, thereby creating the field of optical mineralogy.A. D. Morrison-Low (2004) "Brewster, Sir David (1781–1868)" in ''Oxford Dictionary of National Biography'' For this work, William Whewell dubbed him the "father of modern experimental optics" and "the Johannes Kepler of o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mirrors
A mirror, also known as a looking glass, is an object that reflects an image. Light that bounces off a mirror forms an image of whatever is in front of it, which is then focused through the lens of the eye or a camera. Mirrors reverse the direction of light at an angle equal to its incidence. This allows the viewer to see themselves or objects behind them, or even objects that are at an angle from them but out of their field of view, such as around a corner. Natural mirrors have existed since prehistoric times, such as the surface of water, but people have been manufacturing mirrors out of a variety of materials for thousands of years, like stone, metals, and glass. In modern mirrors, metals like silver or aluminium are often used due to their high reflectivity, applied as a thin coating on glass because of its naturally smooth and very hard surface. A mirror is a wave reflector. Light consists of waves, and when light waves reflect from the flat surface of a mirror, thos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Richard Bradley (botanist)
Richard Bradley Fellow of the Royal Society, FRS (1688 – 5 November 1732) was an English naturalist specialising in botany. He published important works on ecology, horticulture, and natural history. Biography Little is known about Bradley's childhood aside from an early interest in gardening and the fact that he lived in the vicinity of London, a city at the time with many amateur naturalists. Though Bradley lacked a university education, his first publication, ''Treatise of Succulent Plants'', gained him traction with influential patrons like James Petiver and later, Hans Sloane. With their support, he was proposed and elected a Fellow of the Royal Society, Fellow of the Royal Society in 1712, at the age of 24. In 1714, Bradley visited the Netherlands and took an interest in horticulture. He spent the next decade back in England writing treatises on topics related to this central interest, like weather, fertiliser, productivity (ecology), productivity, and hybrid (biology ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Symmetrical
Symmetry () in everyday life refers to a sense of harmonious and beautiful proportion and balance. In mathematics, the term has a more precise definition and is usually used to refer to an object that is invariant under some transformations, such as translation, reflection, rotation, or scaling. Although these two meanings of the word can sometimes be told apart, they are intricately related, and hence are discussed together in this article. Mathematical symmetry may be observed with respect to the passage of time; as a spatial relationship; through geometric transformations; through other kinds of functional transformations; and as an aspect of abstract objects, including theoretic models, language, and music. This article describes symmetry from three perspectives: in mathematics, including geometry, the most familiar type of symmetry for many people; in science and nature; and in the arts, covering architecture, art, and music. The opposite of symmetry is asymmetry, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magic Lantern
The magic lantern, also known by its Latin name , is an early type of image projector that uses pictures—paintings, prints, or photographs—on transparent plates (usually made of glass), one or more lens (optics), lenses, and a light source. Because a single lens inverts an image projected through it (as in the phenomenon which inverts the image of a camera obscura), slides are inserted upside down in the magic lantern, rendering the projected image correctly oriented. It was mostly developed in the 17th century and commonly used for entertainment purposes. It was increasingly used for education during the 19th century. Since the late 19th century, smaller versions were also mass-produced as toys. The magic lantern was in wide use from the 18th century until the mid-20th century when it was superseded by a compact version that could hold many 35 mm photographic slides: the slide projector. Technology Apparatus The magic lantern used a concave mirror behind a light so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Camera Obscura
A camera obscura (; ) is the natural phenomenon in which the rays of light passing through a aperture, small hole into a dark space form an image where they strike a surface, resulting in an inverted (upside down) and reversed (left to right) projector, projection of the view outside. ''Camera obscura'' can also refer to analogous constructions such as a darkened room, box or tent in which an exterior image is projected inside or onto a translucent screen viewed from outside. ''Camera obscuras'' with a lens in the opening have been used since the second half of the 16th century and became popular as aids for drawing and painting. The technology was developed further into the photographic camera in the first half of the 19th century, when ''camera obscura'' boxes were used to exposure (photography), expose photosensitivity, light-sensitive materials to the projected image. The image (or the principle of its projection) of a lensless ''camera obscura'' is also referred to as a " ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sir George Mackenzie, 7th Baronet
Sir George Steuart Mackenzie, 7th Baronet Royal Society of London, FRS FRSE FSA (22 June 1780–26 October 1848) was a Scottish geologist, chemist and agricultural improver. Life The only son of Major General Sir Alexander Mackenzie of Coul (d.1796), a General in the Bengal Army, by his wife Katharine Ramsay (d.1806), daughter of Robert Ramsay of Camno, he was born on 22 June 1780. He was tutored privately and spent one year at Royal High School, Edinburgh, Edinburgh's High School (1795/6). He then studied sciences at the University of Edinburgh. In 1796, he succeeded to the baronetcy at 16, on his father's death. He first became known to scientists in 1800, when he claimed proof of the identity of diamond with carbon by a series of experiments concerning the formation of steel by the combination of diamonds with iron; for these experiments, he is said to have made free use of his mother's jewels. In 1799, he was elected a Fellow of the Royal Society of Edinburgh. His propos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Camera Lucida
A ''camera lucida'' is an optical device used as a drawing aid by artists and microscopy, microscopists. It projects an optics, optical superimposition of the subject being viewed onto the surface upon which the artist is drawing. The artist sees both scene and drawing surface simultaneously, as in a photographic double exposure. This allows the artist to duplicate key points of the scene on the drawing surface, thus aiding in the accurate rendering of perspective. History The ''camera lucida'' was patented in 1806 by the English chemist William Hyde Wollaston. The basic optics were described 200 years earlier by the German astronomer Johannes Kepler in his ''Dioptrice'' (1611), but there is no evidence he constructed a working ''camera lucida''. There is also evidence to suggest that the Elizabethan spy Arthur Gregory's 1596 "perspective box" operated on at least highly similar principles to the later ''camera lucida'', but the secretive nature of his work and fear of rivals ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
