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Wood Effect
Robert Williams Wood (May 2, 1868 – August 11, 1955) was an American physicist and inventor who made pivotal contributions to the field of optics. He pioneered infrared and ultraviolet photography. Wood's patents and theoretical work inform modern understanding of the physics of ultraviolet light, and made possible myriad uses of UV fluorescence which became popular after World War I.Wood, Robert W. (July 13, 1920). "Flash-telescope." . Washington, DC: U.S. Patent and Trademark Office.Wood, Robert W. (May 22, 1923). "Optical Method." . Washington, DC: U.S. Patent and Trademark Office.Wood, Robert W. (June 29, 1926). "Optical toy." . Washington, DC: U.S. Patent and Trademark Office. He published many articles on spectroscopy, phosphorescence, diffraction, and ultraviolet light. Early life and education Robert W. Wood was born in Concord, Massachusetts to Robert Williams Wood, Senior. His father had been born in Massachusetts in 1803, was a physician in Maine until 1838, then ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Concord, Massachusetts
Concord () is a town in Middlesex County, Massachusetts, in the United States. At the 2020 census, the town population was 18,491. The United States Census Bureau considers Concord part of Greater Boston. The town center is near where the confluence of the Sudbury and Assabet rivers forms the Concord River. The area that became the town of Concord was originally known as Musketaquid, an Algonquian word for "grassy plain." Concord was established in 1635 by a group of English settlers; by 1775, the population had grown to 1,400. As dissension between colonists in North America and the British crown intensified, 700 troops were sent to confiscate militia ordnance stored at Concord on April 19, 1775.Chidsey, p. 6. This is the total size of Smith's force. The ensuing conflict, the battles of Lexington and Concord, were the incidents (including the shot heard round the world) that triggered the American Revolutionary War. A rich literary community developed in Concord during the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ultraviolet Photography
Ultraviolet photography is a photographic process of recording images by using radiation from the ultraviolet (UV) spectrum only. Images taken with ultraviolet radiation serve a number of scientific, medical or artistic purposes. Images may reveal deterioration of art works or structures not apparent under light. Diagnostic medical images may be used to detect certain skin disorders or as evidence of injury. Some animals, particularly insects, use ultraviolet wavelengths for vision; ultraviolet photography can help investigate the markings of plants that attract insects, while invisible to the unaided human eye. Ultraviolet photography of archaeological sites may reveal artifacts or traffic patterns not otherwise visible. Ultraviolet images have no color since ultraviolet radiation is invisible to human eyes. Photographs of dyes that fluoresce under ultraviolet illumination are examples of ultraviolet fluorescence photography. Overview Light (visible electromagnetic spectrum) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Henry Augustus Rowland
Henry Augustus Rowland (November 27, 1848 – April 16, 1901) was an American physicist and Johns Hopkins educator. Between 1899 and 1901 he served as the first president of the American Physical Society. He is remembered primarily for the high quality of the diffraction gratings he made and for the work he did with them on the solar spectrum. Early life, family and education Rowland was born in Honesdale, Pennsylvania, where his father Henry Augustus Rowland was a Presbyterian pastor. From an early age, the younger Rowland exhibited marked scientific tastes and spent his spare time in electrical and chemical experiments. He graduated from Rensselaer Polytechnic Institute in Troy, New York in 1870. Career After college, Rowland worked for the Western New York railway, but he did not like the work. He became an instructor in natural science at the University of Wooster in Wooster, Ohio. He resigned in order to return to Troy as assistant professor of physics at Rensselaer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Wisconsin
A university () is an institution of higher (or tertiary) education and research which awards academic degrees in several academic disciplines. Universities typically offer both undergraduate and postgraduate programs. In the United States, the designation is reserved for colleges that have a graduate school. The word ''university'' is derived from the Latin ''universitas magistrorum et scholarium'', which roughly means "community of teachers and scholars". The first universities were created in Europe by Catholic Church monks. The University of Bologna (''Università di Bologna''), founded in 1088, is the first university in the sense of: *Being a high degree-awarding institute. *Having independence from the ecclesiastic schools, although conducted by both clergy and non-clergy. *Using the word ''universitas'' (which was coined at its foundation). *Issuing secular and non-secular degrees: grammar, rhetoric, logic, theology, canon law, notarial law.Hunt Janin: "The university ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heinrich Rubens
Heinrich Rubens (30 March 1865, Wiesbaden, Nassau, Germany – 17 July 1922, Berlin, Germany) was a German physicist. He is known for his measurements of the energy of black-body radiation which led Max Planck to the discovery of his radiation law. This was the genesis of quantum theory. After having attended realgymnasium ''Wöhlerschule'' in Frankfurt am Main, he started in 1884 to study electrical engineering at the technical universities in Darmstadt and Berlin. H. Kant''Heinrich Rubens'' Deutsche Biographie. The following year he switched to physics at the University of Berlin which was more to his liking. W. Westphal, ''Heinrich Rubens'', Die Naturwissenschaften 10 (48), 1017–1020 (1922). After just one semester there he transferred to Strasbourg. There he benefited much from the lectures by August Kundt who in 1888 took over the vacant position of Hermann Helmholtz at the University of Berlin. Rubens followed after and got his doctors degree there the same year. In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Humboldt University Of Berlin
Humboldt-Universität zu Berlin (german: Humboldt-Universität zu Berlin, abbreviated HU Berlin) is a German public research university in the central borough of Mitte in Berlin. It was established by Frederick William III on the initiative of Wilhelm von Humboldt, Johann Gottlieb Fichte and Friedrich Ernst Daniel Schleiermacher as the University of Berlin () in 1809, and opened in 1810, making it the oldest of Berlin's four universities. From 1828 until its closure in 1945, it was named Friedrich Wilhelm University (german: Friedrich-Wilhelms-Universität). During the Cold War, the university found itself in East Berlin and was ''de facto'' split in two when the Free University of Berlin opened in West Berlin. The university received its current name in honour of Alexander and Wilhelm von Humboldt in 1949. The university is divided into nine faculties including its medical school shared with the Freie Universität Berlin. The university has a student enrollment of around 32 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aurora (astronomy)
An aurora (plural: auroras or aurorae), also commonly known as the polar lights, is a natural light display in Earth's sky, predominantly seen in high-latitude regions (around the Arctic and Antarctic). Auroras display dynamic patterns of brilliant lights that appear as curtains, rays, spirals, or dynamic flickers covering the entire sky. Auroras are the result of disturbances in the magnetosphere caused by the solar wind. Major disturbances result from enhancements in the speed of the solar wind from coronal holes and coronal mass ejections. These disturbances alter the trajectories of charged particles in the magnetospheric plasma. These particles, mainly electrons and protons, precipitate into the upper atmosphere (thermosphere/ exosphere). The resulting ionization and excitation of atmospheric constituents emit light of varying colour and complexity. The form of the aurora, occurring within bands around both polar regions, is also dependent on the amount of accelerati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Roxbury Latin School
The Roxbury Latin School is a private boys' day school that was founded in 1645 in the town of Roxbury, Massachusetts, Roxbury (now a neighborhood of Boston, Massachusetts) by the Rev. John Eliot (missionary), John Eliot under a charter received from Charles I of England, King Charles I of England. It bills itself as the "oldest independent school in continuous existence" in North America. Located since 1927 at 101 St. Theresa Avenue in the West Roxbury, Massachusetts, West Roxbury neighborhood of Boston, Massachusetts, Boston, the school now serves roughly 300 boys in grades seven through twelve. Eliot founded the school "to fit [students] for public service both in church and in commonwealth in succeeding ages," and the school still considers instilling a desire to perform public service among its principal missions. The school's endowment is estimated at $189 million, the largest of any boys' day school in the United States. The school maintains a need-blind admissions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hawaiian Islands
The Hawaiian Islands ( haw, Nā Mokupuni o Hawai‘i) are an archipelago of eight major islands, several atolls, and numerous smaller islets in the North Pacific Ocean, extending some from the island of Hawaii in the south to northernmost Kure Atoll. Formerly the group was known to Europeans and Americans as the Sandwich Islands, a name that James Cook chose in honor of the 4th Earl of Sandwich, the then First Lord of the Admiralty. Cook came across the islands by chance when crossing the Pacific Ocean on his Third Voyage in 1778, on board HMS ''Resolution''; he was later killed on the islands on a return visit. The contemporary name of the islands, dating from the 1840s, is derived from the name of the largest island, Hawaii Island. Hawaii sits on the Pacific Plate and is the only U.S. state that is not geographically connected to North America. It is part of the Polynesia subregion of Oceania. The state of Hawaii occupies the archipelago almost in its entirety (includin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diffraction
Diffraction is defined as the interference or bending of waves around the corners of an obstacle or through an aperture into the region of geometrical shadow of the obstacle/aperture. The diffracting object or aperture effectively becomes a secondary source of the propagating wave. Italian scientist Francesco Maria Grimaldi coined the word ''diffraction'' and was the first to record accurate observations of the phenomenon in 1660. In classical physics, the diffraction phenomenon is described by the Huygens–Fresnel principle that treats each point in a propagating wavefront as a collection of individual spherical wavelets. The characteristic bending pattern is most pronounced when a wave from a coherent source (such as a laser) encounters a slit/aperture that is comparable in size to its wavelength, as shown in the inserted image. This is due to the addition, or interference, of different points on the wavefront (or, equivalently, each wavelet) that travel by paths of d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphorescence
Phosphorescence is a type of photoluminescence related to fluorescence. When exposed to light (radiation) of a shorter wavelength, a phosphorescent substance will glow, absorbing the light and reemitting it at a longer wavelength. Unlike fluorescence, a phosphorescent material does not immediately reemit the radiation it absorbs. Instead, a phosphorescent material absorbs some of the radiation energy and reemits it for a much longer time after the radiation source is removed. In a general sense, there is no distinct boundary between the emission times of fluorescence and phosphorescence (i.e.: if a substance glows under a black light it is generally considered fluorescent, and if it glows in the dark it is often simply called phosphorescent). In a modern, scientific sense, the phenomena can usually be classified by the three different mechanisms that produce the light, and the typical timescales during which those mechanisms emit light. Whereas fluorescent materials stop emit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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