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Square Tiling Honeycomb
In the geometry of Hyperbolic space, hyperbolic 3-space, the square tiling honeycomb is one of 11 paracompact regular honeycombs. It is called ''paracompact'' because it has infinite Cell (geometry), cells, whose vertices exist on horospheres and converge to a single ideal point at infinity. Given by Schläfli symbol , it has three square tilings, , around each edge, and six square tilings around each vertex, in a cube, cubic vertex figure.Coxeter ''The Beauty of Geometry'', 1999, Chapter 10, Table III Rectified order-4 square tiling It is also seen as a rectified order-4 square tiling honeycomb, r: Symmetry The square tiling honeycomb has three reflective symmetry constructions: as a regular honeycomb, a half symmetry construction ↔ , and lastly a construction with three types (colors) of checkered square tilings ↔ . It also contains an index 6 subgroup [4,4,3*] ↔ [41,1,1], and a radial subgroup [4,(4,3)*] of index 48, with a right dihedral angle, dihedral-angled ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
H3 443 FC Boundary
H3, H03 or H-3 may refer to: Entertainment * ''Happy Hustle High'', a manga series by Rie Takada, originally titled "H3 School!" * H3 (film), ''H3'' (film), a 2001 film about the 1981 Irish hunger strike * h3h3Productions, styled "[h3]", a satirical YouTube channel Science * Triatomic hydrogen (H3), an unstable molecule * Trihydrogen cation (H3+), one of the most abundant ions in the universe * Tritium (Hydrogen-3, or H-3), an isotope of hydrogen * ATC code H03 ''Thyroid therapy'', a subgroup of the Anatomical Therapeutic Chemical Classification System * British NVC community H3, a heath community of the British National Vegetation Classification system * Histamine H3 receptor, Histamine H3 receptor, a human gene * Histone H3, a component of DNA higher structure in eukaryotic cells * *h3, , one of the three laryngeals in the reconstructed Proto-Indo-European language * Hekla 3 eruption, a huge volcanic eruption around 1000 BC Computing * , the level-3 HTML element#heading ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fundamental Domain
Given a topological space and a group acting on it, the images of a single point under the group action form an orbit of the action. A fundamental domain or fundamental region is a subset of the space which contains exactly one point from each of these orbits. It serves as a geometric realization for the abstract set of representatives of the orbits. There are many ways to choose a fundamental domain. Typically, a fundamental domain is required to be a connected subset with some restrictions on its boundary, for example, smooth or polyhedral. The images of a chosen fundamental domain under the group action then tile the space. One general construction of fundamental domains uses Voronoi cells. Hints at a general definition Given an action of a group ''G'' on a topological space ''X'' by homeomorphisms, a fundamental domain for this action is a set ''D'' of representatives for the orbits. It is usually required to be a reasonably nice set topologically, in one of several preci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Octahedral
In geometry, an octahedron (plural: octahedra, octahedrons) is a polyhedron with eight faces. The term is most commonly used to refer to the regular octahedron, a Platonic solid composed of eight equilateral triangles, four of which meet at each vertex. A regular octahedron is the dual polyhedron of a cube. It is a rectified tetrahedron. It is a square bipyramid in any of three orthogonal orientations. It is also a triangular antiprism in any of four orientations. An octahedron is the three-dimensional case of the more general concept of a cross polytope. A regular octahedron is a 3-ball in the Manhattan () metric. Regular octahedron Dimensions If the edge length of a regular octahedron is ''a'', the radius of a circumscribed sphere (one that touches the octahedron at all vertices) is :r_u = \frac a \approx 0.707 \cdot a and the radius of an inscribed sphere (tangent to each of the octahedron's faces) is :r_i = \frac a \approx 0.408\cdot a while the midradius, which t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dihedral Angle
A dihedral angle is the angle between two intersecting planes or half-planes. In chemistry, it is the clockwise angle between half-planes through two sets of three atoms, having two atoms in common. In solid geometry, it is defined as the union of a line and two half-planes that have this line as a common edge. In higher dimensions, a dihedral angle represents the angle between two hyperplanes. The planes of a flying machine are said to be at positive dihedral angle when both starboard and port main planes (commonly called wings) are upwardly inclined to the lateral axis. When downwardly inclined they are said to be at a negative dihedral angle. Mathematical background When the two intersecting planes are described in terms of Cartesian coordinates by the two equations : a_1 x + b_1 y + c_1 z + d_1 = 0 :a_2 x + b_2 y + c_2 z + d_2 = 0 the dihedral angle, \varphi between them is given by: :\cos \varphi = \frac and satisfies 0\le \varphi \le \pi/2. Alternatively, if an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
H3 444 Boundary 0100
H3, H03 or H-3 may refer to: Entertainment * ''Happy Hustle High'', a manga series by Rie Takada, originally titled "H3 School!" * ''H3'' (film), a 2001 film about the 1981 Irish hunger strike * h3h3Productions, styled " 3, a satirical YouTube channel Science * Triatomic hydrogen (H3), an unstable molecule * Trihydrogen cation (H3+), one of the most abundant ions in the universe * Tritium (Hydrogen-3, or H-3), an isotope of hydrogen * ATC code H03 ''Thyroid therapy'', a subgroup of the Anatomical Therapeutic Chemical Classification System * British NVC community H3, a heath community of the British National Vegetation Classification system * Histamine H3 receptor, a human gene * Histone H3, a component of DNA higher structure in eukaryotic cells * , one of the three laryngeals in the reconstructed Proto-Indo-European language * Hekla 3 eruption, a huge volcanic eruption around 1000 BC Computing * , the level-3 HTML heading markup element * HTTP/3, the third revision ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
H3 444 FC Boundary
H3, H03 or H-3 may refer to: Entertainment * ''Happy Hustle High'', a manga series by Rie Takada, originally titled "H3 School!" * ''H3'' (film), a 2001 film about the 1981 Irish hunger strike * h3h3Productions, styled " 3, a satirical YouTube channel Science * Triatomic hydrogen (H3), an unstable molecule * Trihydrogen cation (H3+), one of the most abundant ions in the universe * Tritium (Hydrogen-3, or H-3), an isotope of hydrogen * ATC code H03 ''Thyroid therapy'', a subgroup of the Anatomical Therapeutic Chemical Classification System * British NVC community H3, a heath community of the British National Vegetation Classification system * Histamine H3 receptor, a human gene * Histone H3, a component of DNA higher structure in eukaryotic cells * , one of the three laryngeals in the reconstructed Proto-Indo-European language * Hekla 3 eruption, a huge volcanic eruption around 1000 BC Computing * , the level-3 HTML heading markup element * HTTP/3, the third revision ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Order-4 Square Tiling Honeycomb
In the geometry of hyperbolic 3-space, the order-4 square tiling honeycomb is one of 11 paracompact regular honeycombs. It is ''paracompact'' because it has infinite cells and vertex figures, with all vertices as ideal points at infinity. Given by Schläfli symbol , it has four square tilings around each edge, and infinite square tilings around each vertex in a square tiling vertex figure.Coxeter ''The Beauty of Geometry'', 1999, Chapter 10, Table III Symmetry The order-4 square tiling honeycomb has many reflective symmetry constructions: as a regular honeycomb, ↔ with alternating types (colors) of square tilings, and with 3 types (colors) of square tilings in a ratio of 2:1:1. Two more half symmetry constructions with pyramidal domains have ,4,1+,4symmetry: ↔ , and ↔ . There are two high-index subgroups, both index 8: ,4,4*↔ 4,4,4,4,1+) with a pyramidal fundamental domain: (4,∞,4)),((4,∞,4))or ; and ,4*,4 with 4 orthogonal sets of ultra-parallel mirror ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vertex Figure
In geometry, a vertex figure, broadly speaking, is the figure exposed when a corner of a polyhedron or polytope is sliced off. Definitions Take some corner or Vertex (geometry), vertex of a polyhedron. Mark a point somewhere along each connected edge. Draw lines across the connected faces, joining adjacent points around the face. When done, these lines form a complete circuit, i.e. a polygon, around the vertex. This polygon is the vertex figure. More precise formal definitions can vary quite widely, according to circumstance. For example Coxeter (e.g. 1948, 1954) varies his definition as convenient for the current area of discussion. Most of the following definitions of a vertex figure apply equally well to infinite tessellation, tilings or, by extension, to Honeycomb (geometry), space-filling tessellation with polytope Cell (geometry), cells and other higher-dimensional polytopes. As a flat slice Make a slice through the corner of the polyhedron, cutting through all the edges ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Square Tiling
In geometry, the square tiling, square tessellation or square grid is a regular tiling of the Euclidean plane. It has Schläfli symbol of meaning it has 4 squares around every vertex. Conway called it a quadrille. The internal angle of the square is 90 degrees so four squares at a point make a full 360 degrees. It is one of three regular tilings of the plane. The other two are the triangular tiling and the hexagonal tiling. Uniform colorings There are 9 distinct uniform colorings of a square tiling. Naming the colors by indices on the 4 squares around a vertex: 1111, 1112(i), 1112(ii), 1122, 1123(i), 1123(ii), 1212, 1213, 1234. (i) cases have simple reflection symmetry, and (ii) glide reflection symmetry. Three can be seen in the same symmetry domain as reduced colorings: 1112i from 1213, 1123i from 1234, and 1112ii reduced from 1123ii. Related polyhedra and tilings This tiling is topologically related as a part of sequence of regular polyhedra and tilings, extending ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ideal Point
In hyperbolic geometry, an ideal point, omega point or point at infinity is a well-defined point outside the hyperbolic plane or space. Given a line ''l'' and a point ''P'' not on ''l'', right- and left-limiting parallels to ''l'' through ''P'' converge to ''l'' at ''ideal points''. Unlike the projective case, ideal points form a boundary, not a submanifold. So, these lines do not intersect at an ideal point and such points, although well-defined, do not belong to the hyperbolic space itself. The ideal points together form the Cayley absolute or boundary of a hyperbolic geometry. For instance, the unit circle forms the Cayley absolute of the Poincaré disk model and the Klein disk model. While the real line forms the Cayley absolute of the Poincaré half-plane model . Pasch's axiom and the exterior angle theorem still hold for an omega triangle, defined by two points in hyperbolic space and an omega point. Properties * The hyperbolic distance between an ideal point and an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Horosphere
In hyperbolic geometry, a horosphere (or parasphere) is a specific hypersurface in hyperbolic space, hyperbolic ''n''-space. It is the boundary of a horoball, the limit of a sequence of increasing balls sharing (on one side) a tangent hyperplane and its point of tangency. For ''n'' = 2 a horosphere is called a horocycle. A horosphere can also be described as the limit of the hyperspheres that share a tangent hyperplane at a given point, as their radii go towards infinity. In Euclidean geometry, such a "hypersphere of infinite radius" would be a hyperplane, but in hyperbolic geometry it is a horosphere (a curved surface). History The concept has its roots in a notion expressed by Friedrich Ludwig Wachter, F. L. Wachter in 1816 in a letter to his teacher Carl Friedrich Gauss, Gauss. Noting that in Euclidean geometry the limit of a sphere as its radius tends to infinity is a plane, Wachter affirmed that even if the Euclid's fifth postulate, fifth postulate were false, there would n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
