All articles starting with P
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Poincaré (lunar crater)
Poincaré, also Poincare, is an IAU-approved 345.99-km-wide impact crater on the Moon's far side at -56.86°, 163.99°E, a superposed basin inside the South Pole-Aitken basin crossed by planned NASA Endurance rover traverses.
Poincaré algebra
The Poincaré algebra is the ten-dimensional Lie algebra of the Poincaré group, the symmetry group of flat spacetime, named for Henri Poincaré, who studied the group in 1905.
Poincaré conjecture
The Poincaré conjecture, also called Smale's second problem, states that every closed, simply connected 3-dimensional manifold is the 3-sphere; Grigori Perelman proved it in 2002.
Poincaré disk model
The Poincaré disk model is a conformal model of hyperbolic geometry in which the hyperbolic plane is drawn as the interior of a circle, introduced by Eugenio Beltrami in 1868.
Poincaré duality
Poincaré duality is a theorem of algebraic topology stating that on a closed orientable n-manifold, the k-th cohomology group is isomorphic to the (n − k)-th homology group.
Poincaré group
The Poincaré group, or inhomogeneous Lorentz group, is the group of all symmetries of Minkowski spacetime in special relativity, combining Lorentz transformations with spacetime translations.
Poincaré half-plane model
The Poincaré half-plane model represents hyperbolic geometry on the upper half of the complex plane, where geodesics are vertical lines and semicircles meeting the real axis at right angles.
Poincaré homology sphere
The Poincaré homology sphere, also called the Poincaré dodecahedral space, is a closed 3-manifold with the same homology as the 3-sphere, whose nontrivial fundamental group disproved Poincaré's 1900 claim.
Poincaré inequality
The Poincaré inequality, a result in Sobolev space theory named after Henri Poincaré, bounds a function's size on a bounded domain by the size of its gradient.
Poincaré map
The Poincaré map, or first-return map, records where a continuous dynamical system's trajectories cross a transversal surface, reducing the flow to a lower-dimensional discrete map.
Poincaré plot
The Poincaré plot, also called a Lorenz plot, is a scatter plot of each value of a time series against the next, used in heart rate variability analysis.
Poincaré recurrence theorem
The Poincaré recurrence theorem, also called the Poincaré return theorem, states that in a finite measure-preserving dynamical system almost every point returns to its starting set infinitely often.
Poincaré sphere
The Poincaré sphere is a geometric representation mapping every polarization state of light to a point on or inside a unit sphere, introduced by Henri Poincaré in 1892.
Poinpy
Poinpy is a 2022 vertical-climbing mobile game by Ojiro Fumoto, creator of Downwell, originally a Netflix Games exclusive; players slingshot upward collecting fruit recipes for a beast, later re-released free by Devolver Digital.
Poinsettia
Poinsettia (Euphorbia pulcherrima, cuetlaxochitl, flor de Nochebuena), a Mexican shrub grown for red winter bracts; introduced to the U.S. by Joel Poinsett in 1828; short-day flowering; low toxicity.
Point (geography)
Point (geography): a tapering, generally low-elevation piece of land projecting into a sea, lake, or river, less prominent than a cape; gazetteer feature code PT, related to headland, promontory, and cape.
Point (geometry)
A point in geometry is an object that marks a location and has no size, one of the primitive objects from which lines and figures are built.
Point (typography)
The point, also called the typographic point, is the basic unit for stating font size, defined digitally as exactly 1/72 of an inch; 12 points make a pica.
Point absorber
A point absorber is a buoy-like wave energy converter, small relative to the wavelength, that captures energy from waves and is the most common wave energy converter type.
Point Arguello
Point Arguello is a coastal site near Lompoc, California, that served from 1958 to 1964 as the Naval Missile Facility, the main launch complex of the Navy's Pacific Missile Range.
Point at infinity
A point at infinity, also called an ideal point, is a point added to each family of parallel lines so that any two distinct lines meet in exactly one point.
Point bar
A point bar is a sediment deposit built on the inside of a river bend where slower water drops its load, a defining feature of meandering rivers.
Point Beach nuclear power plant
Point Beach Nuclear Plant is a two-unit nuclear power plant on Lake Michigan near Two Rivers, Wisconsin, the state's only operating nuclear plant, licensed to run into the 2050s.
Point Blank (1967 film)
Point Blank (1967) is John Boorman's neo-noir revenge thriller starring Lee Marvin as Walker, left for dead on Alcatraz; adapted from Westlake's The Hunter, 92 minutes, MGM, released 30 August 1967.
Point Blank (2019 film)
Point Blank (2019) is a Netflix action thriller directed by Joe Lynch, a remake of Fred Cavayé's French film À bout portant, starring Anthony Mackie, Frank Grillo, and Marcia Gay Harden, released July 12, 2019.
Point Break
Point Break (1991) is Kathryn Bigelow's action film in which FBI agent Johnny Utah (Keanu Reeves) infiltrates surfing bank robbers, the Ex-Presidents, led by Bodhi (Patrick Swayze); originally titled Riders on the Storm, remade in 2015, sequel series planned.
Point Break (2015 film)
Point Break (2015) is Ericson Core's remake of the 1991 cult action film, starring Luke Bracey as FBI recruit Johnny Utah and Édgar Ramírez as Bodhi. Released December 25, 2015 by Warner Bros., it grossed $15.6 million in the US and scored 12% on Rotten Tomatoes.
Point charge
A point charge is an idealized electric charge concentrated at a single point in space, the simplest source in electrostatics, from whose fields more complicated charge distributions are built.
Point cloud
A point cloud, or point cloud data, is a large set of 3D points representing object or terrain surfaces, typically produced by lidar or derived from overlapping photographs.
Point Cloud Library
The Point Cloud Library (PCL) is an open-source C++ library for 2D/3D image and point cloud processing, introduced by Radu Bogdan Rusu and Steve Cousins of Willow Garage in 2011.