Vertex

From Wikipedia, the free encyclopedia

Vertex (Latin: corner; plural vertices or vertexes) can have a number of meanings, dependent on the context.

Contents 1 Mathematics 2 Science 3 Other fields 4 Organizations 4.1 Companies 4.2 Societies 5 Music

[edit] Mathematics

In mathematics the term vertex is used with different meaning in several disciplines.

• In geometry, a vertex is a corner of
  • an angle: the point where two rays begin or meet, where two line segments join or meet, where two lines cross (intersect), or any appropriate combination of rays, segments and lines that result in two straight "sides" meeting at one place. In Euclidean geometry, an endpoint is not a vertex unless it is the endpoint of two or more segments or rays (or segments and rays) and is thus very different than a graph theory vertex.
  • a polygon: any point on the polygon where two sides (line segments) meet and connect.
  • a polyhedron: any point where three or more edges meet and connect to each other. The edges are the connections (line segments as shared sides) of two or more faces (polygons).
  • a polytope: any point where the corners of three or more cells meet and connect to each other.

See Point (geometry)

• In graph theory, a graph describes a set of connections between objects. Each object is called a node or vertex. The connections themselves are called edges or arcs. An object that has only one connection (often geometrically depicted as an endpoint) is still a vertex.
• For curves a vertex is a point on the curve with a local minimum or maximum of curvature.

[edit] Science

The term vertex is used in several scientific fields:

• In optics, a vertex (or surface vertex) is the point where the surface of an optical element crosses the optical axis. It is one of the cardinal points of an optical system.
• In nuclear and particle physics, a vertex is the interaction point, where some subnuclear process occurs, changing the number and/or momenta of interacting particles or nuclei.
• In anatomy, the vertex is the highest point of the skull in the anatomical position (i.e. standing upright). It lies between the parietal bones in the median sagittal plane.
• In oceanography, VERTEX was a study in 1981, organised by John Martin called the Vertical Transport and Exchange of Oceanic Particulate Program, to determine just how much carbon in the form of deteriorated phytoplankton, sank to the sea floor over a given period of time. By placing sediment traps on the Pacific Ocean floor, it was possible to measure the amount of carbon trapped by the biosphere and compare this to the phytoplankton growth in the surface layers. This enabled scientists to measure the importance of the phytoplankton in the Carbon Cycle. The VERTEX study led John Martin to the Iron Hypothesis, which maybe the long term cure for Global Warming.

[edit] Other fields

• In astrology, the vertex is a point in space seen near the Western horizon (and the Descendant) in the two-dimensional horoscope. More precisely it is where the Prime Vertical meets the ecliptic in the west. Directly opposite this point in the east is the anti-vertex. In astrological theory, planet(s) close to it are supposed to lend their personality to the event(s) that the chart captures.

[edit] Organizations

[edit] Companies

• Vertex Inc. provides tax compliance software and services for U.S. Corporate tax, Sales tax, Use tax, communications tax, and Payroll tax, and also international Value added tax.
• Vertex - Business Process Outsourcing. Previously a division of United Utilities plc, sold to a venture capital consortium January 2007.
• Vertex Software develops web-based customer management solutions.
• Vertex Pharmaceuticals is a biotech company, with 2005 revenues of $161 million, that is developing small molecule therapeutics for the treatment of HCV infection, inflammation, autoimmune diseases, cancer, pain, cystic fibrosis and other diseases, both independently and in collaboration with other pharmaceutical and biotechnology companies.
• Vertex Media Group is a marketing company specializing in online advertising.
• Vertex Systems Oy is a CAD software company.

[edit] Societies

• Vertex Society A society for people scoring above an IQ of 160 sd16 on professional, standardized intelligence tests only. This translates to a rarity of 1/11000 of the general population or roughly only 590 000 people of the current 6.5 billion.

[edit] Music

Vertex is also used as a name in music:

• VerTex is a song in In The Groove (game).
• Vertex is also an album by Buck 65.
• Vertex is a band formed in 1996 by Stephen Pearcy from Ratt.