query: What is a prism?

title: Bauernfeind prism

text: Bauernfeind prism A Bauernfeind prism is a type of reflecting prism used to deviate a beam of light by 45° to 60°, depending on its construction, while neither flipping nor rotating the image. It is named for its inventor, the German expert of geodesy . The beam is reflected twice in the prism, with one reflection happening at less than the critical angle, therefore the prism requires a reflective coating for this surface to be usable in practice. A Bauernfeind prism with 45° beam deviation is also known as a half-penta prism or semipentaprism. A Bauernfeind prism is used together

title: Bauernfeind prism

text: with a Schmidt roof prism to form a Schmidt–Pechan prism. The Bauernfeind prism is commonly used in microscope tubes and in geodesy to deviate the path to the eyepiece in order make the device more ergonomic. More recent applications are glasses that deflect the viewing angle either downwards (for relaxed reading or watching TV), or upwards (for watching a climber while belaying). Bauernfeind prism A Bauernfeind prism is a type of reflecting prism used to deviate a beam of light by 45° to 60°, depending on its construction, while neither flipping nor rotating the image. It is named for its

title: Prism (Prism album)

text: Prism (Prism album) Prism is the self-titled debut album by Canadian rock band Prism. It was released in May 1977 on the Canadian record label GRT. It was produced primarily by Bruce Fairbairn and the majority of songs written by Jim Vallance (he also served as co-producer on two tracks). It achieved platinum status in Canada (in excess of 100,000 units sold). "Prism" peaked at #137 on the Billboard 200 in November 1977. "Spaceship Superstar" became the band's signature song and a staple of Canadian rock radio. Record producer Bruce Fairbairn and songwriter Jim Vallance both went on to achieve

title: Prism (Prism album)

text: huge international success. All songs written by Jim Vallance under the pseudonym Rodney Higgs, unless otherwise noted. The song "Open Soul Surgery" was covered by April Wine in their 1986 album Walking Through Fire. with: Prism (Prism album) Prism is the self-titled debut album by Canadian rock band Prism. It was released in May 1977 on the Canadian record label GRT. It was produced primarily by Bruce Fairbairn and the majority of songs written by Jim Vallance (he also served as co-producer on two tracks). It achieved platinum status in Canada (in excess of 100,000 units sold). "Prism" peaked at

title: Apollo PRISM

text: Apollo PRISM PRISM (Parallel Reduced Instruction Set Multiprocessor) was Apollo Computer's high-performance CPU used in their DN10000 series workstations. It was for some time the fastest microprocessor available, a high fraction of a Cray-1 in a workstation. Hewlett Packard purchased Apollo in 1989, ending development of PRISM, although some of PRISM's ideas were later used in HP's own HP-PA Reduced instruction set computer (RISC) and Itanium processors. PRISM was based on what would be known today as a VLIW-design, while most efforts of the era, 1988, were based on a more "pure" RISC approach. In early RISC designs, the core

title: Triangular prism

text: in the case of the triangular prism). In Coxeter's notation the triangular prism is given the symbol −1. The triangular prism exists as cells of a number of four-dimensional uniform 4-polytopes, including: Triangular prism In geometry, a triangular prism is a three-sided prism; it is a polyhedron made of a triangular base, a translated copy, and 3 faces joining corresponding sides. A right triangular prism has rectangular sides, otherwise it is "oblique". A uniform triangular prism is a right triangular prism with equilateral bases, and square sides. Equivalently, it is a polyhedron of which two faces are parallel, while the

title: Prism (geometry)

text: applies if the joining faces are rectangular. If the joining edges and faces are not perpendicular to the base faces, it is called an oblique prism. For example a parallelepiped is an "oblique prism" of which the base is a parallelogram, or equivalently a polyhedron with six faces which are all parallelograms. A truncated prism is a prism with nonparallel top and bottom faces. Some texts may apply the term rectangular prism or square prism to both a right rectangular-sided prism and a right square-sided prism. A "right p-gonal prism" with rectangular sides has a Schläfli symbol { } ×

title: Wedge prism

text: Wedge prism The wedge prism is a prism with a shallow angle between its input and output surfaces. This angle is usually 3 degrees or less. Refraction at the surfaces causes the prism to deflect light by a fixed angle. When viewing a scene through such a prism, objects will appear to be offset by an amount that varies with their distance from the prism. For a wedge prism in air, rays of light passing through the prism are deflected by the angle δ, which is approximately given by where "n" is the index of refraction of the prism material,

title: Prism TV

text: when CenturyTel agreed to purchase Embarq to form CenturyLink in 2009. CenturyLink (still known as CenturyTel) began rolling out what was to eventually be known as Prism TV in October 2009 in Jefferson City, Missouri. It adopted the Prism TV name in 2011, based on the Embarq TV infrastructure. Over time, CenturyLink began rolling out Prism TV in markets as they were upgraded from the old copper-based services to fiber-optic communication, eventually offering the service in markets in Arizona, Colorado, Florida, Iowa, Minnesota, Missouri, Nebraska, Nevada, North Carolina, Oregon, Washington, and Wisconsin. Other markets will follow once their lines are

title: Prism

text: secondary quality distinction. Newton discussed prism dispersion in great detail in his book "Opticks". He also introduced the use of more than one prism to control dispersion. Newton's description of his experiments on prism dispersion was qualitative. A quantitative description of multiple-prism dispersion was not needed until multiple prism laser beam expanders were introduced in the 1980s. "Dispersive prisms" are used to break up light into its constituent spectral colors because the refractive index depends on frequency; the white light entering the prism is a mixture of different frequencies, each of which gets bent slightly differently. Blue light is slowed

title: Wedge prism

text: target is carefully calibrated to the desired plot size, and the plot is defined as all the area in which the target is "in" as viewed through the prism. Wedge prism The wedge prism is a prism with a shallow angle between its input and output surfaces. This angle is usually 3 degrees or less. Refraction at the surfaces causes the prism to deflect light by a fixed angle. When viewing a scene through such a prism, objects will appear to be offset by an amount that varies with their distance from the prism. For a wedge prism in air,

title: Abbe prism

text: Abbe prism In optics, an Abbe prism, named for its inventor, the German physicist Ernst Abbe, is a type of "constant deviation dispersive prism" similar to a Pellin–Broca prism. The prism consists of a block of glass forming a right prism with 30°–60°–90° triangular faces. When in use, a beam of light enters face AB, is refracted and undergoes total internal reflection from face BC, and is refracted again on exiting face AC. The prism is designed such that one particular wavelength of the light exits the prism at a deviation angle (relative to the light's original path) of exactly

title: Nomarski prism

text: is oriented obliquely with respect to the flat surface of the prism. The Nomarski modification causes the light rays to come to a focal point outside the body of the prism, and allows greater flexibility so that when setting up the microscope the prism can be actively focused. Nomarski prism A Nomarski prism is a modification of the Wollaston prism that is used in differential interference contrast microscopy. It is named after its inventor, Polish physicist Georges Nomarski. Like the Wollaston prism, the Nomarski prism consists of two birefringent crystal wedges (e.g. quartz or calcite) cemented together at the hypotenuse

title: Prism

text: Prism In optics, a prism is a transparent optical element with flat, polished surfaces that refract light. At least two of the flat surfaces must have an angle between them. The exact angles between the surfaces depend on the application. The traditional geometrical shape is that of a triangular prism with a triangular base and rectangular sides, and in colloquial use "prism" usually refers to this type. Some types of optical prism are not in fact in the shape of geometric prisms. Prisms can be made from any material that is transparent to the wavelengths for which they are designed.

title: Roof prism

text: it is invert for the other half of the beam. Therefore, a roof prism can be used only with some distance to focal planes, or the "edge" of the roof would introduce slight distortions. Furthermore, the angle between the two faces has to be very close to 90°, or image quality would be degraded. The simplest roof prism is the Amici roof prism, with other common roof prism designs being the Abbe–Koenig prism, the Schmidt–Pechan prism and probably the best known being the roof pentaprism pictured here. A porro prism is not a roof prism, contrary to popular notion, as

title: Abbe prism

text: 60°. This is the minimum possible deviation of the prism, all other wavelengths being deviated by greater angles. By rotating the prism (in the plane of the diagram) around any point O on the face AB, the wavelength which is deviated by 60° can be selected. The dispersive Abbe prism should not be confused with the non-dispersive Porro–Abbe or Abbe–Koenig prisms. Abbe prism In optics, an Abbe prism, named for its inventor, the German physicist Ernst Abbe, is a type of "constant deviation dispersive prism" similar to a Pellin–Broca prism. The prism consists of a block of glass forming a

title: Prism (geometry)

text: {p}. A right rectangular prism is also called a "cuboid", or informally a "rectangular box". A right square prism is simply a "square box", and may also be called a "square cuboid". A "right rectangular prism" has Schläfli symbol { }×{ }×{ }. An "n"-prism, having regular polygon ends and rectangular sides, approaches a cylindrical solid as "n" approaches infinity. The term uniform prism or "semiregular prism" can be used for a "right prism" with square sides, since such prisms are in the set of uniform polyhedra. A "uniform p-gonal prism" has a Schläfli symbol t{2,p}. Right prisms with regular

title: Nomarski prism

text: Nomarski prism A Nomarski prism is a modification of the Wollaston prism that is used in differential interference contrast microscopy. It is named after its inventor, Polish physicist Georges Nomarski. Like the Wollaston prism, the Nomarski prism consists of two birefringent crystal wedges (e.g. quartz or calcite) cemented together at the hypotenuse (e.g. with Canada balsam). One of the wedges is identical to a conventional Wollaston wedge and has the optical axis oriented parallel to the surface of the prism. The second wedge of the prism is modified by cutting the crystal in such a manner that the optical axis

title: Roof prism

text: Roof prism A roof prism (also called a Dach prism or Dachkanten prism, from the German: "Dachkante", lit. "roof edge") is a reflective optical prism containing a section where two faces meet at a 90° angle. These two 90° faces resemble the roof of a building, giving this prism type its name. Reflection from the two 90° faces returns an image that is flipped laterally across the axis where the faces meet. Characteristic for a roof prism is that the beam is split in half, with one half of the beam hitting first one face then the other face, while

title: Rectified prism

text: a semiregular cuboctahedron. Rectified star prisms also exist, like a 5/2 form: The dual of a "rectified prism" is a joined prism or joined bipyramid, in Conway polyhedron notation. The join operation adds vertices at the center of faces, and replaces edges with rhombic faces between original and the neighboring face centers. The "joined square prism" is the same topology as the rhombic dodecahedron. The "joined triangular prism" is the Herschel graph. Rectified prism In geometry, a rectified prism (also rectified bipyramid) is one of an infinite set of polyhedra, constructed as a rectification of an "n"-gonal prism, truncating the

title: Dove prism

text: Dove prism A Dove prism is a type of reflective prism which is used to invert an image. Dove prisms are shaped from a truncated right-angle prism. The Dove prism is named for its inventor, Heinrich Wilhelm Dove. A beam of light travelling parallel to the longitudinal axis, entering one of the sloped faces of the prism undergoes total internal reflection from the inside of the longest (bottom) face and emerges from the opposite sloped face. Images passing through the prism are flipped (mirrored), and because only one reflection takes place, the image is also inverted but not laterally transposed.

title: Amici prism

text: Amici prism An Amici prism, named for the astronomer Giovanni Amici, is a type of compound dispersive prism used in spectrometers. The Amici prism consists of two triangular prisms in contact, with the first typically being made from a medium-dispersion crown glass, and the second a higher-dispersion flint glass. Light entering the first prism is refracted at the first air-glass interface, refracted again at the interface between the two prisms, and then exits the second prism at near-normal incidence. The prism angles and materials are chosen such that one wavelength (colour) of light, the "centre wavelength", exits the prism parallel

title: Dispersive prism

text: a dispersive prism is seen on the cover of Pink Floyd's "The Dark Side of the Moon", one of the best-selling albums of all time. The iconic graphic shows a coherent ray of white light entering the prism and beginning to disperse, and shows the spectrum leaving the prism. Dispersive prism In optics, a dispersive prism is an optical prism, usually having the shape of a geometrical triangular prism, used as a spectroscopic component. Spectral dispersion is the best known property of optical prisms, although not the most frequent purpose of using optical prisms in practice. Triangular prisms are used

title: Amici prism

text: much more compact than multiple prism arrangements typical of that period for producing high spectral dispersion, Amici's invention quickly caught the attention of researchers throughout Europe. However, the dispersion of Amici prisms can be accurately calculated using the multiple-prism dispersion theory assuming no spatial separation between the prism components. The dispersive Amici prism should not be confused with the non-dispersive Amici roof prism. Amici prism An Amici prism, named for the astronomer Giovanni Amici, is a type of compound dispersive prism used in spectrometers. The Amici prism consists of two triangular prisms in contact, with the first typically being made

title: Porro prism

text: a distance of at least one beam diameter. A variation on the double Porro prism is the Porro-Abbe prism. Porro prism In optics, a Porro prism, named for its inventor Ignazio Porro, is a type of "reflection prism" used in optical instruments to alter the orientation of an image. It consists of a block of glass shaped as a right geometric prism with right-angled triangular end faces. In operation, light enters the large rectangular face of the prism, undergoes total internal reflection twice from the sloped faces, and exits again through the large rectangular face. Because the light exits and

title: Porro prism

text: Porro prism In optics, a Porro prism, named for its inventor Ignazio Porro, is a type of "reflection prism" used in optical instruments to alter the orientation of an image. It consists of a block of glass shaped as a right geometric prism with right-angled triangular end faces. In operation, light enters the large rectangular face of the prism, undergoes total internal reflection twice from the sloped faces, and exits again through the large rectangular face. Because the light exits and enters the glass only at normal incidence, the prism is not dispersive. An image travelling through a Porro prism

title: Triangular prism

text: Triangular prism In geometry, a triangular prism is a three-sided prism; it is a polyhedron made of a triangular base, a translated copy, and 3 faces joining corresponding sides. A right triangular prism has rectangular sides, otherwise it is "oblique". A uniform triangular prism is a right triangular prism with equilateral bases, and square sides. Equivalently, it is a polyhedron of which two faces are parallel, while the surface normals of the other three are in the same plane (which is not necessarily parallel to the base planes). These three faces are parallelograms. All cross-sections parallel to the base faces

title: Rochon prism

text: applications other polarisers are preferred. Rochon prism A Rochon prism is a type of polariser. It is made from two prisms of a birefringent material such as calcite, which are cemented together. The Rochon prism was invented by and is named after Abbé Alexis Marie Rochon. It is in many ways similar to the Wollaston prism, but one ray (the ordinary ray) passes through the prism undeviated. The Sénarmont prism is similar but transmits the s-polarized ray undeviated. In both the Rochon and the Sénarmont prisms the undeviated ray is ordinary on both sides of the interface. Rochon prisms are

title: Rochon prism

text: Rochon prism A Rochon prism is a type of polariser. It is made from two prisms of a birefringent material such as calcite, which are cemented together. The Rochon prism was invented by and is named after Abbé Alexis Marie Rochon. It is in many ways similar to the Wollaston prism, but one ray (the ordinary ray) passes through the prism undeviated. The Sénarmont prism is similar but transmits the s-polarized ray undeviated. In both the Rochon and the Sénarmont prisms the undeviated ray is ordinary on both sides of the interface. Rochon prisms are commercially available, but for many

title: Prism adaptation

text: The direct effect adaptation observed as a result of prism exposure persists and results in what is known as the prism adaptation negative after-effect. The negative after-effect causes the initial attempts in pointing to the visual target during the post-test to be in the direction opposite that of the visual shift. For example, if the observer was exposed to rightward shifting prisms, then the initial pointing errors induced by the after-effect would be to the left of the target. The extent of the observed after-effects reflects the amount of realignment that has taken place in visual and proprioceptive spatial maps

title: Amici prism

text: to (but offset from) the entrance beam. The prism assembly is thus a "direct-vision prism", and is commonly used as such in hand-held spectroscopes. Other wavelengths are deflected at angles depending on the glass dispersion of the materials. Looking at a light source through the prism thus shows the optical spectrum of the source. By 1860, Amici realized that one can join this type of prism back-to-back with a reflected copy of itself, producing a three-prism arrangement known as a double Amici prism. This doubling of the original prism increases the angular dispersion of the assembly, and also has the

title: Prism (geometry)

text: tetrahedra removed between pairs of triangles. A frustum is topologically identical to a prism, with trapezoid lateral faces and different sized top and bottom polygons. A star prism is a nonconvex polyhedron constructed by two identical star polygon faces on the top and bottom, being parallel and offset by a distance and connected by rectangular faces. A "uniform star prism" will have Schläfli symbol {"p"/"q"} × { }, with "p" rectangle and 2 {"p"/"q"} faces. It is topologically identical to a "p"-gonal prism. A crossed prism is a nonconvex polyhedron constructed from a prism, where the base vertices are inverted

title: Prism (geometry)

text: Prism (geometry) In geometry, a prism is a polyhedron comprising an "n"-sided polygonal base, a second base which is a translated copy (rigidly moved without rotation) of the first, and "n" other faces (necessarily all parallelograms) joining corresponding sides of the two bases. All cross-sections parallel to the bases are translations of the bases. Prisms are named for their bases, so a prism with a pentagonal base is called a pentagonal prism. The prisms are a subclass of the prismatoids. A right prism is a prism in which the joining edges and faces are perpendicular to the base faces. This

title: Porro prism

text: roof is usually left out. Sometimes only one small window as entrance surface and one window as exit surface are polished. The distinction between a roof prism and a porro prism is that for the roof prism the roof edge lies in the same plane as entrance and exit beam, while for a porro prism the (left out) roof edge is orthogonal to the plane formed by the beams. Furthermore, the roof prism has no displacement and a deviation typically between 45° and 90°, while in a single porro prism the beam is typically deviated by 180° and displaced by

title: Prism correction

text: displacement at 100 cm, or 1 meter. This can be represented mathematically as: where formula_2 is the amount of prism correction in prism dioptres, and formula_3 is the angle of deviation of the light. For a prism with apex angle formula_4 and refractive index formula_5, Prentice's rule, named so after the optician Charles F. Prentice, is a formula used to determine the amount of induced prism in a lens: where: The primary use of Prentice's rule is that under certain circumstances, the prescribed prism can be obtained without grinding prism into the lenses, by decentering the lenses as worn by

title: Delta prism

text: the odd parity of three reflections involved. If the base surface is roofed, the number of reflections increases to an even four. The roofed prism thus acts as an image erector, rotating the image without the mirroring effect of the unroofed form. The delta prism is named for its shape being similar to the uppercase Greek letter Δ (delta). Delta prism A delta prism is an optical element providing a compact folded form of the Dove prism. When used in the normal orientation, the prism inverts the image (that is, rotates it 180 degrees); rotating the orientation results in image

title: Prism spectrometer

text: be used to determine the composition of a material from its emitted spectral lines. A prism spectrometer may be used to measure the refractive index of a material if the wavelengths of the light used are known. The calibration of a prism spectrometer is carried out with known spectral lines from vapor lamps or laser light. Prism spectrometer A prism spectrometer is an optical spectrometer which uses a dispersive prism as its dispersive element. The prism refracts light into its different colors (wavelengths). The dispersion occurs because the angle of refraction is dependent on the refractive index of the prism's

title: Prism correction

text: an eyeglass prescription, the base is typically specified as up, down, in, or out, but left and right are also used sometimes. Whether a patient needs this type of correction can be determined by a variety of methods. Prism correction is commonly specified in "prism dioptres", a unit of angular measurement that is loosely related to the dioptre. Prism dioptres are represented by the Greek symbol delta (Δ) in superscript. A prism of power 1 would produce 1 unit of displacement for an object held 100 units from the prism. Thus a prism of 1 would produce 1 cm visible

title: Prism Rhythm

text: Prism Rhythm On August 31, 2010, a novel based on "Prism Rhythm" was published by Paradigm. The story was written by RICOTTA. A four-panel comic strip manga of "Prism Rhythm" called "Lamp of Comic: Prism Rhythm" has been published, with a total of five pages. Each page focuses on the protagonist Kazuki interacting with a different heroine, Elsterrier, Kasumi, Lia, Gin and Caroline. The opening theme to Prism Rhythm is 'Pure My Voices' sung by Ave; new. The ending song to Elsterrier's route is 'Prism' sung by Matsutade Mio, Lia's ending song is 'Present' sung by Fujimori Yukina, Kasumi's ending

title: PRism

text: PRism PRism is an open access peer-reviewed electronic academic journal published by Massey University and Bond University, covering public relations. The editor-in-chief is Elspeth Tilley (Massey University). The journal was established in 2003. "PRism" ranked as a "B" journal in both the 2008 and 2010 listings of international refereed journal quality rankings issued biannually from the Australian Business Deans Council (ABDC). This means "PRism" is consistently and formally recognised by independent external assessment as a "well regarded journal in the field" that "publishes research of a good standard in terms of originality, significance and rigour and papers are fully refereed

title: Prism coupler

text: the solution to a reciprocal problem. In the reciprocal problem, a waveguide mode in the film (travelling to the left in the first figure) is incident on the prism coupler. Barring significant scattering at the prism interface, the waveguide mode in the reciprocal problem retains its form as a mode and propagates under the prism, losing power as it propagates due to radiation into the prism. The power in the prism emerges as a collimated beam at an angle determined by the propagation constant of the waveguide mode and the refractive index of the prism. Radiation into the prism occurs

title: Rectified prism

text: Rectified prism In geometry, a rectified prism (also rectified bipyramid) is one of an infinite set of polyhedra, constructed as a rectification of an "n"-gonal prism, truncating the vertices down to the midpoint of the original edges. In Conway polyhedron notation, it is represented as "aPn", an ambo-prism. The lateral squares or rectangular faces of the prism become squares or rhombic faces, and new isosceles triangle faces are truncations of the original vertices. An "n"-gonal form has 3"n" vertices, 6"n" edges, and 2+3"n" faces: 2 regular "n"-gons, "n" rhombi, and 2"n" triangles. The "rectified square prism" is the same as

title: Pellin–Broca prism

text: Pellin–Broca prism A Pellin–Broca prism is a type of constant-deviation dispersive prism similar to an Abbe prism. The prism is named for its inventors, the French instrument maker Ph. Pellin and professor of physiological optics André Broca. The prism consists of a four-sided block of glass shaped as a right prism with 90°, 75°, 135°, and 60° angles on the end faces. Light enters the prism through face AB, undergoes total internal reflection from face BC, and exits through face AD. The refraction of the light as it enters and exits the prism is such that one particular wavelength of

title: Prism

text: hyper- or hypotropia. In contrast, spectacles with prisms of equal power for both eyes, called yoked prisms (also: "conjugate prisms", "ambient lenses" or "performance glasses") shift the visual field of both eyes to the same extent. Prism In optics, a prism is a transparent optical element with flat, polished surfaces that refract light. At least two of the flat surfaces must have an angle between them. The exact angles between the surfaces depend on the application. The traditional geometrical shape is that of a triangular prism with a triangular base and rectangular sides, and in colloquial use "prism" usually refers

title: Amici roof prism

text: Amici roof prism An Amici roof prism, named for its inventor, the Italian astronomer Giovanni Amici, is a type of reflecting prism used to deviate a beam of light by 90° while simultaneously inverting the image. It is commonly used in the eyepieces of telescopes as an image erecting system. It is sometimes called an Amici prism or right angle roof prism. The non-dispersive Amici roof prism should not be confused with the dispersive Amici prism. The device is shaped like a standard right-angled prism with an additional "roof" section (consisting of two faces meeting at a 90° angle) on

title: The Black Prism

text: colors of Luxin. Most often than not, this is accomplished by the Prism, a religious leader and political figurehead who rules over the Seven Satrapies as Emperor, although his political power is ceremonial at best. The Prism can draft every color of Luxin, and does not require colored glasses as he possesses the unique ability to split white light into its component colors. Superchromats have extremely acute vision when it come to colors. The inverse of those who are Subchromats (colorblindness), Superchromats can see the minute changes in shades between what most people would assume are the same color. This

title: The Black Prism

text: Tyrea. When he mentions the box Garadul took from Kip, Andross immediately asks if it is "the white luxin," a supposedly mythical substance. His brother Gavin was aware of it as well, and Andross——not knowing Dazen isn't Gavin——assumes he knows what it is. Andross Guile orders his son to defeat Garadul's armies, but at all costs retrieve the dagger. Kip, the Prism, Ironfist, and Liv leave for Tyrea to defend Garriston from Garadul's armies, sinking several pirates along the way. Corvan reaches Garriston at about this time, and agrees to lead the city's defense. Despite their real-world friendship, the Prism

title: Prism spectrometer

text: Prism spectrometer A prism spectrometer is an optical spectrometer which uses a dispersive prism as its dispersive element. The prism refracts light into its different colors (wavelengths). The dispersion occurs because the angle of refraction is dependent on the refractive index of the prism's material, which in turn is slightly dependent on the wavelength of light that is traveling through it. Light is emitted from a source such as a vapor lamp. A slit selects a thin strip of light which passes through the collimator where it gets parallelized. The aligned light then passes through the prism in which it

title: Hexagonal prism

text: Hexagonal prism In geometry, the hexagonal prism is a prism with hexagonal base. This polyhedron has 8 faces, 18 edges, and 12 vertices. Since it has eight faces, it is an octahedron. However, the term "octahedron" is primarily used to refer to the "regular octahedron", which has eight triangular faces. Because of the ambiguity of the term "octahedron" and the dissimilarity of the various eight-sided figures, the term is rarely used without clarification. Before sharpening, many pencils take the shape of a long hexagonal prism. If faces are all regular, the hexagonal prism is a semiregular polyhedron, more generally, a

title: Schmidt–Pechan prism

text: or revert (flip) the image, depending on the orientation of the prism, but not both at the same time. For the Schmidt-Pechan design, the upper prism from the Pechan design is replaced with a Schmidt roof prism, so the Schmidt–Pechan prism can both invert and revert the image and so act as an image rotator. The lower prism is known as a half-penta prism or Bauernfeind prism. The image's handedness is not changed by the Schmidt-Pechan. The design of the two prisms is such that the entrance beam and exit beam are coaxial, i.e. the Schmidt–Pechan prism does not deviate

title: Sénarmont prism

text: e-ray. The Sénarmont prism is similar in construction and action to the Rochon prism, as in both polarizers the ray that is not deflected is the o-ray after the internal interface, while the deflected ray is the e-ray. However, in the Rochon prism, it is the p-polarized ray that remains an o-ray on both sides of the interface, and is therefore not deflected, while the s-polarized ray changes from o-ray to e-ray and is therefore deflected. Sénarmont prism The Sénarmont prism is a type of polariser. It is made from two prisms of a birefringent material such as calcite, usually

title: Dispersive prism

text: Dispersive prism In optics, a dispersive prism is an optical prism, usually having the shape of a geometrical triangular prism, used as a spectroscopic component. Spectral dispersion is the best known property of optical prisms, although not the most frequent purpose of using optical prisms in practice. Triangular prisms are used to disperse light, that is, to break light up into its spectral components (the colors of the rainbow). Different wavelengths (colors) of light will be deflected by the prism at different angles, producing a spectrum on a detector (or seen through an eyepiece). This is a result of the

title: Compound prism

text: Compound prism A compound prism is a set of multiple triangular prism elements placed in contact, and often cemented together to form a solid assembly. The use of multiple elements gives several advantages to an optical designer: The simplest compound prism is a doublet, consisting of two elements in contact, as shown in the figure at right. A ray of light passing through the prism is refracted at the first air-glass interface, again at the interface between the two glasses, and a final time at the exiting glass-air interface. The deviation angle formula_2 of the ray is given by the

title: Schmidt–Pechan prism

text: Schmidt–Pechan prism A Schmidt–Pechan prism is a type of optical prism used to rotate an image by 180°. These prisms are commonly used in binoculars as an "image erecting system". The Schmidt–Pechan prism makes use of a roof prism section (from the German: "Dachkante", lit. "roof edge"). A binocular using Schmidt–Pechan prisms can be constructed more compactly than one using Porro or Abbe–Koenig roof prisms. A Schmidt–Pechan prism is sometimes called a Pechan prism pair. The Schmidt-Pechan is based on the Pechan prism design: Both are a composite of two prisms, separated by an air gap. The Pechan will invert

title: Prism lighting

text: Prism lighting Prism lighting is the use of prisms to improve the distribution of light in a space. It is usually used to distribute daylight, and is a form of anidolic lighting. Prism lighting was popular from its introduction in the 1890s through to the 1930s, when cheap electric lights were commonplace and prism lighting became unfashionable. While mass production of prism lighting systems ended around 1940, the 2010s have seen a revival using new materials. The human eye's response to light is non-linear: halving the light level does not halve the perceived brightness of a space, it makes it

title: Abbe–Koenig prism

text: a "roof prism", although this is ambiguous, because other roof prisms exist, such as the Amici and Schmidt–Pechan designs. A variant of the Abbe–Koenig prism replaces the "roof" section of the prism with a single mirror-coated reflecting surface. This type of prism flips the image vertically, but not laterally, changing the handedness of the image to the opposite sense. Abbe–Koenig prism An Abbe–Koenig prism is a type of reflecting prism, used to invert an image (rotate it by 180°). They are commonly used in binoculars and some telescopes for this purpose. The prism is named after Ernst Abbe and Albert

title: Compound prism

text: used for direct-vision dispersion. In order to design such a prism, we let formula_24, and simultaneously solving equations formula_2 and formula_26 gives from which one can obtain the element apex angles formula_8 and formula_9 from the mean refractive indices of the glasses chosen: Note that this formula is only accurate under the small angle approximation. While the doublet prism is the simplest compound prism type, the double-Amici prism is much more common. This prism is a three-element system (a triplet), in which the first and third elements share both the same glass and the same apex angles. The design layout

title: Prism Rhythm

text: song is 'Dreams' sung by Urakasumi Shino, and Gin's ending song is 'Smile' sung by Nakasehina. Haida Mikage provides the vocals for Caroline's ending theme, 'Spring Snow'. Two discs for Prism Rhythm's original soundtrack have been produced. On Getchu, "Prism Rhythm" was ranked first with the highest sales in May, 2010. Then in the following month June, "Prism Rhythm's" ranking dropped to 26th place. "Prism Rhythm" came 8th in the sales ranking of the year 2010, whilst Hello, Good-bye came 6th. On PCpress, "Prism Rhythm" came 5th in the reservation ranking log of April, 2010. Prism Rhythm On August 31,

title: Prism (geometry)

text: product of two polygons. Regular duoprisms are represented as {"p"}×{"q"}. A twisted prism is a nonconvex prism polyhedron constructed by a uniform "q"-prism with the side faces bisected on the square diagonal, and twisting the top, usually by radians ( degrees) in the same direction, causing side triangles to be concave. A twisted prism cannot be dissected into tetrahedra without adding new vertices. The smallest case, triangular form, is called a Schönhardt polyhedron. A "twisted prism" is topologically identical to the antiprism, but has half the symmetry: D, ["n",2], order 2"n". It can be seen as a convex antiprism, with

title: Prism lighting

text: specified angle, ideally sending it nearly horizontally into the room. Redirecting films can be used as a substitute for opaque blinds. Prism lighting Prism lighting is the use of prisms to improve the distribution of light in a space. It is usually used to distribute daylight, and is a form of anidolic lighting. Prism lighting was popular from its introduction in the 1890s through to the 1930s, when cheap electric lights were commonplace and prism lighting became unfashionable. While mass production of prism lighting systems ended around 1940, the 2010s have seen a revival using new materials. The human eye's

title: Porro–Abbe prism

text: beam. The image is rotated 180° in the process, and for this reason the prism is used as an "image erection system" in some binoculars, and camera viewfinders. The prism is not dispersive since light enters and exits the prism only at normal incidence. Since the light is reflected an even number of times, the image's handedness is not changed. For ease of manufacture, the prism is often made as a pair of double-right-angled prisms and the two halves cemented together. A single half of the assembly is sometimes also called a Porro–Abbe prism. Porro–Abbe prism A Porro–Abbe prism (sometimes

title: PRISM (reactor)

text: PRISM (reactor) PRISM (Power Reactor Innovative Small Module, sometimes S-PRISM from SuperPRISM) is a nuclear power plant design by GE Hitachi Nuclear Energy (GEH). The S-PRISM represents GEH's Generation IV reactor solution to closing the nuclear fuel cycle and is also part of its Advanced Recycling Center (ARC) proposition to U.S. Congress to deal with nuclear waste. S-PRISM is a commercial implementation of the Integral Fast Reactor developed by Argonne National Laboratory between 1984 and 1994. It is a sodium-cooled fast breeder reactor, based on the Experimental Breeder Reactor II (EBR-II) design, scaled up by a factor of ten. The

title: Prism Skylabs

text: Prism Skylabs Prism Skylabs is a technology company headquartered in San Francisco, California that connects cameras within businesses to machine learning and A.I. technology in the cloud, to transform these devices into tools for Business Intelligence. Prism launched as a company in 2011 at the TechCrunch Disrupt awards, where it was featured as a finalist in the Startup Battlefield competition. Prism Skylabs' technology is deployed in over 80 countries and is used by more than 300 customers around the world. Prism Skylabs provides several mobile and web applications that are used by enterprise customers to make decisions using data from

title: Compound prism

text: a symmetric form of the more general triplet prism, in which the apex angles and glasses of the two outer elements may differ (see the figure at right). Although triplet prisms are rarely found in optical systems, their added degrees of freedom beyond the double-Amici design allow for improved dispersion linearity. The deviation angle of the triplet prism is obtained by concatenating the refraction equations at each interface: Here to the ray deviation angle is given by formula_35. Compound prism A compound prism is a set of multiple triangular prism elements placed in contact, and often cemented together to form

title: Tidal prism

text: not as great as in shallower estuaries creating a smaller tidal prism and a longer residence time. The size of an inlet or estuary is determined, according to O’Brien by tidal prism. Tidal prism magnitude can be calculated by multiplying the area of the estuary by the tidal range of that estuary. During spring or fall tides, when sea level is relatively high and floods backbarrier areas that are normally above tidal inundation, the cross sectional area at the entrance of the estuary increases as tidal prism increases. Since tidal prism is largely a function of area of open water

title: Tidal prism

text: Tidal prism A tidal prism is the volume of water in an estuary or inlet between mean high tide and mean low tide, or the volume of water leaving an estuary at ebb tide. The inter-tidal prism volume can be expressed by the relationship: "P=H A", where "H" is the average tidal range and "A" is the average surface area of the basin. It can also be thought of as the volume of the incoming tide plus the river discharge. Simple tidal prism models stated the relationship of river discharge and inflowing ocean water as Prism=Volume of ocean water coming

title: Roof prism

text: diffraction from the discontinuity at the roof crest. The unwanted interference effects are suppressed by vapour-depositing a special dielectric coating known as a phase-compensating coating on the roof surfaces of the roof prism. This coating corrects for the difference in geometric phase between s- and p-polarized light so both have effectively the same phase shift, preventing image-degrading interference. Roof prism A roof prism (also called a Dach prism or Dachkanten prism, from the German: "Dachkante", lit. "roof edge") is a reflective optical prism containing a section where two faces meet at a 90° angle. These two 90° faces resemble the

title: Sentenced to Prism

text: overcome his prejudices, his assumptions, and his preoccupations to relearn what life, communication, companionship, government, and even his own bodily form mean to him. He and his new-found friends must overcome multiple treacherous acts by his own race in order to survive and thrive on the beautiful, but deadly, planet. Sentenced to Prism Sentenced to Prism (1985) is a science fiction novel by American writer Alan Dean Foster, a stand-alone entry in his Humanx Commonwealth series of books. Like many of his books, Foster creates an extraordinary world that he tries to make unlike anything ever seen by his readers

title: Dispersive prism

text: this case the grating is used in reflection, with light hitting the grating from "inside" the prism before being totally internally reflected back into the prism (and leaving from a different face). The reduction of the light's wavelength inside the prism results in an increase of the resulting spectral resolution by the ratio of the prism's refractive index to that of air. With either a grism or immersed grating, the primary source of spectral dispersion is the grating. Any effect due to chromatic dispersion from the prism itself is incidental, as opposed to actual prism-based spectrometers. An artist's rendition of

title: Pellin–Broca prism

text: are also commonly used in optical atomic spectroscopy. Pellin–Broca prism A Pellin–Broca prism is a type of constant-deviation dispersive prism similar to an Abbe prism. The prism is named for its inventors, the French instrument maker Ph. Pellin and professor of physiological optics André Broca. The prism consists of a four-sided block of glass shaped as a right prism with 90°, 75°, 135°, and 60° angles on the end faces. Light enters the prism through face AB, undergoes total internal reflection from face BC, and exits through face AD. The refraction of the light as it enters and exits the

title: Glan–Foucault prism

text: Glan–Foucault prism A Glan–Foucault prism (also called a Glan–air prism) is a type of prism which is used as a polarizer. It is similar in construction to a Glan–Thompson prism, except that two right-angled calcite prisms are spaced with an air gap instead of being cemented together. Total internal reflection of "p"-polarized light at the air gap means that only "s"-polarized light is transmitted straight through the prism. Compared to the Glan–Thompson prism, the Glan–Foucault has a narrower acceptance angle over which it works, but because it uses an air gap rather than cement, much higher irradiances can be used

title: Blue Prism

text: a number of industries including banking, finance and insurance, consumer package goods, legal services, public sector, professional services, healthcare and utilities. Blue Prism Blue Prism is the trading name of the Blue Prism Group, a UK multinational software corporation that pioneered and makes enterprise robotic process automation software to eliminate low-return, high-risk, manual data entry and processing work. Blue Prism is headquartered in Newton-le-Willows, Merseyside, UK with regional offices in the US and Australia. The company is listed on the London Stock Exchange AIM market. Blue Prism was founded in 2001 by a group of process automation experts to develop

title: Delta prism

text: Delta prism A delta prism is an optical element providing a compact folded form of the Dove prism. When used in the normal orientation, the prism inverts the image (that is, rotates it 180 degrees); rotating the orientation results in image rotation to other arbitrary angles. The base surface must be fabricated with a mirror coating to make it reflective. The other two surfaces are not coated, since they are internally reflective from the ray angles and high-index glass. The simple form of the prism also results in image mirroring along one meridian but not the other, a consequence of

title: Blue Prism

text: Blue Prism Blue Prism is the trading name of the Blue Prism Group, a UK multinational software corporation that pioneered and makes enterprise robotic process automation software to eliminate low-return, high-risk, manual data entry and processing work. Blue Prism is headquartered in Newton-le-Willows, Merseyside, UK with regional offices in the US and Australia. The company is listed on the London Stock Exchange AIM market. Blue Prism was founded in 2001 by a group of process automation experts to develop technology that could be used to improve the efficiency and effectiveness of organisations. Initially their focus was on the white collar

title: Dichroic prism

text: Dichroic prism A dichroic prism is a prism that splits light into two beams of differing wavelength (colour). A trichroic prism assembly combines two dichroic prisms to split an image into 3 colours, typically as red, green and blue of the RGB colour model. They are usually constructed of one or more glass prisms with dichroic optical coatings that selectively reflect or transmit light depending on the light's wavelength. That is, certain surfaces within the prism act as dichroic filters. These are used as beam splitters in many optical instruments. (See: Dichroism, for the etymology of the term.) One common

title: Mozilla Prism

text: Firefox extensions to work in it. The preview announcement of Prism was made in October 2007. On February 1, 2011, Mozilla labs announced it would no longer maintain Prism, its ideas having been subsumed into a newer project called Chromeless. However, the Mozilla Labs mailing list revealed that Chromeless is not in fact a replacement for Prism, and there is currently no Mozilla replacement for the out-of-the-box site-specific browser functionality of Prism, Chromeless instead being a platform for developers rather than users. For a while Prism continued to be maintained under the original name of WebRunner, which then also was

title: Prism adaptation

text: Prism adaptation Prism adaptation is a sensory-motor adaptation that occurs after the visual field has been artificially shifted laterally or vertically. It was first introduced by Hermann von Helmholtz in late 19th-century Germany as supportive evidence for his perceptual learning theory (Helmholtz, 1909/1962). Since its discovery, prism adaptation has been suggested to improve spatial deficits in patients with unilateral neglect. During prism adaptation, an individual wears special prismatic goggles that are made of prism wedges that displace the visual field laterally or vertically. In most cases the visual field is shifted laterally either in the rightward or leftward direction. While

title: PRISM (reactor)

text: PRISM in the UK. In the years that were to follow, analysis refocused on metal chloride e.g. Plutonium(III) chloride, to aid in greater "nuclear waste" closed-fuel cycle capabilities, the "Stable Salt Reactor"(SSR) concept promoted by MOLTEX, was found to be the most competitive for Small modular reactor development by a British-based consultancy firm "Energy Process Development" in 2015. PRISM (reactor) PRISM (Power Reactor Innovative Small Module, sometimes S-PRISM from SuperPRISM) is a nuclear power plant design by GE Hitachi Nuclear Energy (GEH). The S-PRISM represents GEH's Generation IV reactor solution to closing the nuclear fuel cycle and is also part

title: PRISM (surveillance program)

text: said in 2013 that it is "absurd and unnatural" for the German authorities to pretend not to have known anything. The German Army was using PRISM to support its operations in Afghanistan as early as 2011. In October 2013, it was reported that the NSA monitored Merkel's cell phone. The United States denied the report, but following the allegations, Merkel called President Obama and told him that spying on friends was "never acceptable, no matter in what situation." Israeli newspaper "Calcalist" discussed the "Business Insider" article about the possible involvement of technologies from two secretive Israeli companies in the PRISM

title: Schmidt–Pechan prism

text: using Porro prism or Abbe–Koenig prism that rely only on total internal reflections. A dielectric mirror coating is comparable in reflection effectivity, but makes the Schmidt-Pechan more expensive. The Schmidt-Pechan furthermore shares the phase correction problems with other roof prisms. Schmidt–Pechan prism A Schmidt–Pechan prism is a type of optical prism used to rotate an image by 180°. These prisms are commonly used in binoculars as an "image erecting system". The Schmidt–Pechan prism makes use of a roof prism section (from the German: "Dachkante", lit. "roof edge"). A binocular using Schmidt–Pechan prisms can be constructed more compactly than one using

title: Deck prism

text: Deck prism A deck prism is a prism inserted into the deck of a ship to provide light down below. For centuries, sailing ships used deck prisms to provide a safe source of natural sunlight to illuminate areas below decks. Before electricity, light below a vessel's deck was provided by candles, oil and kerosene lamps—all dangerous aboard a wooden ship. The deck prism was a clever solution: laid flush into the deck, the glass prism refracted and dispersed natural light into the space below from a small deck opening without weakening the planks or becoming a fire hazard. In normal

title: Prism (geometry)

text: bases and equal edge lengths form one of the two infinite series of semiregular polyhedra, the other series being the antiprisms. The dual of a "right prism" is a bipyramid. The volume of a prism is the product of the area of the base and the distance between the two base faces, or the height (in the case of a non-right prism, note that this means the perpendicular distance). The volume is therefore: where "B" is the base area and "h" is the height. The volume of a prism whose base is a regular "n"-sided polygon with side length "s"

title: Porro–Abbe prism

text: Porro–Abbe prism A Porro–Abbe prism (sometimes called a Abbe–Porro prism), named for Ignazio Porro and Ernst Abbe, is a type of reflection prism used in some optical instruments to alter the orientation of an image. It is a variant of the more common double Porro prism configuration. It is made from a piece of glass shaped like four right-angled reflecting prisms joined face-to-face in a twisted fashion. Light enters one flat face, is internally reflected four times from the sloping faces of the prism, and exits the second flat face offset from, but in the same direction as the entrance

title: Tetrahedral prism

text: first in an infinite series of uniform antiprismatic prisms. The tetrahedral prism, -1, is first in a dimensional series of uniform polytopes, expressed by Coxeter as k series. The tetrahedral prism is the vertex figure for the second, the rectified 5-simplex. The fifth figure is a Euclidean honeycomb, 3, and the final is a noncompact hyperbolic honeycomb, 4. Each uniform polytope in the sequence is the vertex figure of the next. Tetrahedral prism In geometry, a tetrahedral prism is a convex uniform 4-polytope. This 4-polytope has 6 polyhedral cells: 2 tetrahedra connected by 4 triangular prisms. It has 14 faces:

title: Blue Prism

text: January 6, 2017, Blue Prism announced it would open new offices in Austin, Texas, while remaining based in London. At the time, it employed 86 people worldwide. In March 2017, a group of shareholders sold stakes in Blue Prism. At the time, Blue Prism remained based in Merseyside. In June 2017, Blue Prism announced that a new version of its software would run on public clouds such as Amazon Web Services, Microsoft Azure, and Google Cloud Platform. Previously, the software had run on customers' own servers. Blue Prism is built on the Microsoft .NET Framework. It automates any application and

title: Mozilla Prism

text: discontinued in September 2011. Mozilla Prism Mozilla Prism (formerly WebRunner) is a discontinued project which integrated web applications with the desktop, allowing web applications to be launched from the desktop and configured independently of the default web browser. As of November 2010, Prism is listed as an inactive project at the Mozilla labs website. Prism is based on a concept called a site-specific browser (SSB). An SSB is designed to work exclusively with one web application. It doesn't have the menus, toolbars and other accoutrements of a traditional web browser. The software is built upon XULRunner, so it is possible

title: Mozilla Prism

text: Mozilla Prism Mozilla Prism (formerly WebRunner) is a discontinued project which integrated web applications with the desktop, allowing web applications to be launched from the desktop and configured independently of the default web browser. As of November 2010, Prism is listed as an inactive project at the Mozilla labs website. Prism is based on a concept called a site-specific browser (SSB). An SSB is designed to work exclusively with one web application. It doesn't have the menus, toolbars and other accoutrements of a traditional web browser. The software is built upon XULRunner, so it is possible to get some Mozilla

title: Prism coupler

text: at an angle formula_7 normal from the waveguide surface. where formula_9 is the index of refraction of the prism. where formula_11 is the index of air (~1) and formula_6 is the propagation constant of the waveguide. In order to have a guided mode, formula_13. This would imply that formula_14, which is not possible. Prism coupler A prism coupler is a prism designed to couple a substantial fraction of the power contained in a beam of light (e.g., a laser beam) into a thin film to be used as a waveguide without the need for precision polishing of the edge of

title: Porro prism

text: is rotated by 180° and exits in the opposite direction offset from its entrance point. Since the image is reflected twice, the handedness of the image is unchanged. Porro prisms are most often used in pairs, forming a double Porro prism. A second prism, rotated 90° with respect to the first, is placed such that light will traverse both prisms. The net effect of the prism system is a beam parallel to but displaced from its original direction, with the image rotated 180°. As before, the handedness of the image is unchanged. Double Porro prism systems are used in small

title: Abbe–Koenig prism

text: the prism. The light is then reflected from the opposite 30° face and exits, again at normal incidence. The net effect of the internal reflections is to flip the image both vertically and horizontally. This produces a 180° image rotation (without changing the image's handedness) and allows use of the prism as an "image erecting system". Unlike the more common double Porro prism configuration, the Abbe–Koenig prism does not displace the output beam from the input beam, making it advantageous in some instruments. The prism is also less bulky than the double Porro design. The prism is sometimes simply called

title: Wedge prism

text: are most common) and square meters/hectare (1-5 BAF are common). Prism size is chosen to yield a statistically valid estimate of basal area - 6-10 "in" trees per plot are required, which requires a prism of the proper factor depending on the size of the trees being cruised. Larger trees will be "in" from further away, and a larger factor prism (20 or 30 ft/ac, 5–8 m/ha) can be used. Smaller trees will be "out" in a larger factor prism unless they are very close, and consequently a smaller factor prism must be used. Importantly, the bottom edge of the

title: Sénarmont prism

text: Sénarmont prism The Sénarmont prism is a type of polariser. It is made from two prisms of a birefringent material such as calcite, usually cemented together. The Sénarmont prism is named after Henri Hureau de Sénarmont. It is similar to the Rochon and Wollaston prisms. In the Sénarmont prism the s-polarized ray (i.e., the ray with polarization direction perpendicular to the plane in which all rays are contained, called the plane of incidence) passes through without being deflected, while the p-polarized ray (with polarization direction in the plane of incidence) is deflected (refracted) at the internal interface into a different

title: Uniform antiprismatic prism

text: octagonal faces. It has 80 edges, and 32 vertices. Uniform antiprismatic prism In 4-dimensional geometry, a uniform antiprismatic prism or antiduoprism is a uniform 4-polytope with two uniform antiprism cells in two parallel 3-space hyperplanes, connected by uniform prisms cells between pairs of faces. The symmetry of a "p"-gonal antiprismatic prism is [2"p",2,2], order 8"p". A p-gonal antiprismatic prism or p-gonal antiduoprism has 4"p" equilateral triangle, 4"p" square and 4 regular "p"-gon faces. It has 10"p" edges, and 4"p" vertices. There is an infinite series of convex uniform antiprismatic prisms, starting with the "digonal antiprismatic prism" is a tetrahedral prism,

title: Uniform antiprismatic prism

text: Uniform antiprismatic prism In 4-dimensional geometry, a uniform antiprismatic prism or antiduoprism is a uniform 4-polytope with two uniform antiprism cells in two parallel 3-space hyperplanes, connected by uniform prisms cells between pairs of faces. The symmetry of a "p"-gonal antiprismatic prism is [2"p",2,2], order 8"p". A p-gonal antiprismatic prism or p-gonal antiduoprism has 4"p" equilateral triangle, 4"p" square and 4 regular "p"-gon faces. It has 10"p" edges, and 4"p" vertices. There is an infinite series of convex uniform antiprismatic prisms, starting with the "digonal antiprismatic prism" is a tetrahedral prism, with two of the tetrahedral cells degenerated into squares.

title: Nicol prism

text: Nicol prism A Nicol prism is a type of polarizer, an optical device made from calcite crystal used to produce and analyse plane polarized light. It is made in such a way that it eliminates one of the rays by total internal reflection, i.e. the ordinary ray is eliminated and only the extraordinary ray is transmitted through the prism. It was the first type of polarizing prism, invented in 1828 by William Nicol (1770–1851) of Edinburgh. It consists of a rhombohedral crystal of Iceland spar (a variety of calcite) that has been cut at an angle of 68° with respect

title: Dove prism

text: Refraction at the entrance and exit surfaces results in substantial image astigmatism when used in convergent light. Thus the Dove prism is used almost exclusively for images appearing at infinity. If the flat hypoteneuse surface of a Dove prism is cut into a roof shape, the result is an Amici roof prism. A reflection in one axis of a plane is always equivalent to a reflection and rotation in two other axes (with the angle between the source and image being twice the angle between the source and reflection axis of the prism). Thus, Dove prisms can be used to

title: Octahedral prism

text: Octahedral prism In geometry, a octahedral prism is a convex uniform 4-polytope. This 4-polytope has 10 polyhedral cells: 2 octahedra connected by 8 triangular prisms. <BR>Transparent Schlegel diagram The octahedral prism consists of two octahedra connected to each other via 8 triangular prisms. The triangular prisms are joined to each other via their square faces. The octahedron-first orthographic projection of the octahedral prism into 3D space has an octahedral envelope. The two octahedral cells project onto the entire volume of this envelope, while the 8 triangular prismic cells project onto its 8 triangular faces. The triangular-prism-first orthographic projection of the

title: What Is a Nation?

text: What Is a Nation? "What is a Nation?" ("Qu'est-ce qu'une nation?") is an 1882 lecture by French historian Ernest Renan (1823–1892), known for the statements that a nation is "a daily referendum", and that nations are based as much on what the people jointly forget, as what they remember. It is frequently quoted or anthologized in works of history or political science pertaining to nationalism and national identity. Renan wrote "What is a Nation" in order to symbolize the nationalism which was born in France as a result of the French Revolution of 1789. Renan begins his essay by noting

title: Pentagonal prism

text: 4-polytopes in 4 dimensions: Pentagonal prism In geometry, the pentagonal prism is a prism with a pentagonal base. It is a type of heptahedron with 7 faces, 15 edges, and 10 vertices. If faces are all regular, the pentagonal prism is a semiregular polyhedron, more generally, a uniform polyhedron, and the third in an infinite set of prisms formed by square sides and two regular polygon caps. It can be seen as a "truncated pentagonal hosohedron", represented by Schläfli symbol t{2,5}. Alternately it can be seen as the Cartesian product of a regular pentagon and a line segment, and represented

title: Pentagonal prism

text: Pentagonal prism In geometry, the pentagonal prism is a prism with a pentagonal base. It is a type of heptahedron with 7 faces, 15 edges, and 10 vertices. If faces are all regular, the pentagonal prism is a semiregular polyhedron, more generally, a uniform polyhedron, and the third in an infinite set of prisms formed by square sides and two regular polygon caps. It can be seen as a "truncated pentagonal hosohedron", represented by Schläfli symbol t{2,5}. Alternately it can be seen as the Cartesian product of a regular pentagon and a line segment, and represented by the product {5}x{}.