 Plato's Molecule  Ivars Peterson (MathTrek)
In his dialogue Timaeus, the Greek philosopher Plato (427347 B.C.) carefully laid out his reasoning for ascribing certain geometric shapes to the minuscule particles that constituted the four elements of matter. In his view, these elements  fire, air,
...more>>
 A Playground of Thoughts  Takasugi Shinji
Takasugi's "Number Systems of the World" lists dozens of languages; how to count from zero to one hundred in each; and the mathematical meaning of the expressions for each numeral. For example, the French say "93" with quatrevingttreize, which means
...more>>
 Playing with RuthAaron Pairs  Ivars Peterson (MathLand)
On April 8, 1974, Henry (Hank) Aaron hit his 715th major league home run, surpassing the previous mark of 714 career home runs long held by baseball great Babe Ruth. Understandably, the event received considerable coverage in newspapers and magazines
...more>>
 Plexagon  Pleated Hexagon  Paul Bourke, Ron Evans
Plexagon is a new modular geometry based on the radial pleating of polygonal plates, and their joining or cobracing into 3D modules. This engineering approach can form a very practical basis for modular greenhouses (using recycled plastic sheeting) and
...more>>
 Plot a Graph  Vladimir Sorokin; University of Kentucky
An applet that allows you to enter and plot functions of one variable. Enter an expression with a variable x to be plotted, the number of points to calculate, and the range of your variable in the corresponding textfields below the plotting area, and
...more>>
 Plotting Functions of a Complex Variable  George Abdo, Paul Godfrey
Graphs of functions of a complex variable, compared with graphs of functions of a real variable (the Introduction includes a review). Includes Conformal Maps requiring Möbius and SchwartzChristoffel Transformations. Full color images show conformal
...more>>
 Plouffe's Inverter  Simon Plouffe
A database of more than 84,800,000 mathematical constants like Pi, Sqrt(2), Catalan and Euler's gamma. Enter a number, search or browse, and the programs will find what the number is made of. From the author of the Encyclopedia of Integer Sequences (with
...more>>
 Plouffe's Inverter: Table of current records for the computation of constants
Classical constants: Pi, 1/Pi, E, Catalan, Zeta(3), Euler's gamma, log(2), Golden Ratio, Square root of 2, N'th binary digit computations, other interesting computations (Bernoulli numbers, Zeros of Riemann's Zeta Function, Madelung Constant, Khintchine
...more>>
 Plusepsilon.de  Marc Palm
Questionandanswer German language platform for undergraduate and graduate math students. Browse or search questions by users, by tags of math topics, and other options. Not intended as a discussion platform, Plusεpsilon rewards participation
...more>>
 Plus Magazine  Department of Applied Mathematics and Theoretical Physics, University of Cambridge
Plus (formerly PASSMaths) is a triannual online magazine for older pupils and the general public. It publishes articles explaining the diverse applications of mathematics used in solving problems in physics, chemistry, biology, engineering, and economics.
...more>>
 PM Zone Science Search  Popular Mechanics
Enter words describing a concept or keywords you wish to find information about to conduct a keyword search of the science/technology magazine Popular Mechanics. For topics other than science, see the PM Search Page.
...more>>
 PNA: Revista de Investigación en Didáctica de la Matemática
PNA is a peerreview open access research journal published by the Spanish research group "Mathematics Education. Numerical Thinking" of the Andalusian Plan of Research. This journal includes papers in English and Spanish related to the teaching and learning
...more>>
 Podcast Directory: Math  Podseek
Podcasts of various math instruction and tutorials. Log in to rate or review the links.
...more>>
 Poem about the Riemann Zeta Function  Tom Apostol
A poem about the zeta function and the Riemann hypothesis, linked to explanations of the important concepts by Chris Hughes.
...more>>
 Poe's Secret  Ivars Peterson (MathTrek)
Writer Edgar Allan Poe (18091849) is famous for his short stories of the mysterious and the macabre. His popular tale "The GoldBug," published in 1843, is often cited as one of the best works of fiction that turn upon a secret message. Poe had a longstanding
...more>>
 Poincaré Notes  Dave Wilson
"A massively disorganised collection of macros and figures for the Poincaré Disk model of hyperbolic geometry." A page describing some Cabri macros relating to hyperbolic Geometry in the Poincare disc model.
...more>>
 Point Plots and Space Curves  Theo Gray
Download a Mathematica notebook that defines the functions PointParamPlot3D, SpaceCurve, and PointSpaceCurve. These functions let you make discrete point plots in two and three dimensions. The SpaceCurve and PointSpaceCurve functions let you make threedimensional
...more>>
 Poisson Pit: Poisson Probability Calculator  Chuck Anesi
Variously called the Poisson Distribution, Poisson Law of Large Numbers, or Poisson Distribution for Rare Events, the probability function for this discrete distribution of one parameter is given on this site. The Poisson distribution is usually employed
...more>>
 Poles and Zeros of a Causal LTI System  Manfred Thole
A Java applet that shows the domain of a system whose transfer function has two poles and two zeros. Poles and zeros can be dragged with the mouse. The amplitude response and the phase response are shown along the side. Plot: H(s) may take a while.
...more>>
 Poliplus Software
Educational computer algebra, geometry, trigonometry, calculus software for Windows and Macintosh, and Java. Formulae 1 (F1) is a computer algebra system designed for the teaching and exploration of Mathematics. EqnViewer is a Java applet that allows
...more>>
 Polish Mathematical Society, Cracow Division
Council, Committees, Delegates, report of Plenary Meeting; Contact details.
...more>>
 POLYA: Cooperative Solutions of Difficult Problems in Elementary Mathematics  Paul Yiu and Xiaodong Zhang, Moderators; Department of Mathematical Sciences, Florida Atlantic University
An archived discussion group for the cooperative solution of difficult problems in elementary mathematics through calculus, "preferably nontechnical in nature."
...more>>
 Poly and Poly Pro  Pedagoguery Software
Mac and Windows shareware programs for exploring and constructing paper models of polyhedra. With Poly, you can manipulate a polyhedral solid on the computer and print out a flattened version (a net) which can then be cut out, folded, and taped, to produce
...more>>
 Polygon Boolean operations on sets of polygons  Klaas Holwerda
Boolean: GDSII viewer/editor + (boolean) operations on sets of 2d polygons. Operations; Introduction; screenshots; C ++ source, executables and documentation for download; Acknowledgments, Feedback, mailing list; documentation (algorithm); documentation
...more>>
 PolygonFlux  John Miller
An iPad app for exploring the path taken by a point bouncing around inside a regular polygon of 3 to 14 sides. Set the initial angle and starting location, the number of bounces, and the number of sides for the polygon; collect an album of resulting "fluxagons"
...more>>
 Polygons, Polyhedra, Polytopes  Russell Towle
Polytope is the general term of the sequence, point, segment, polygon,
polyhedron, ... . Towle offers several pages devoted to the theory of polytopes, from polygons to star polytopes in 4space, including Mathematica notebooks with constructions.
...more>>
 Polyhedra and Polytopes (The Geometry Junkyard)  David Eppstein, Theory Group, ICS, UC Irvine
An extensive annotated list of links to material on geometric properties of polygons, polyhedra, and higher dimensional polytopes (particularly convex polytopes).
...more>>
 Polyhedra Collection  V. Bulatov
Galleries of polyhedra shown using JPEG pictures and 3D objects in VRML2.0 format. Uniform polyhedra; Duals; Compounds; Johnson's solids; 59 stellations of icosahedron; 270 stellations of deformed dodecahedron; symmetric stellations of rhombic triacontahedron:
...more>>
 Polyhedra (Geometry and the Imagination)  Conway, Doyle, Gilman, Thurston; The Geometry Center
A polyhedron is the threedimensional version of a polygon, a threedimensional figure made by gluing polygons together. This handout discusses polyhedra, presents explorative activities, and supplies a "homework" assignment. Includes the first 20 Greek
...more>>
 Polyhedral Solids  Tom Gettys
The study of polyhedra is one of those special areas of Mathematics which allow the amateur and expert to work with an equal delight. The Platonic Solids; The Archimedean Solids; The KeplerPoinsot Polyhedra; Compound Solids; Stellated Polyhedra. See
...more>>
 Polyhedra  Peter Cromwell
Ancient manuscripts from Egypt and China relate ideas concerning the calculation of the volumes of polyhedra, while the Greek tradition of geometry gave us the construction of the regular polyhedra or Platonic solids. In modern times, polyhedra and their
...more>>
 Polyhedra  Rolf Asmund
A gallery of regular polyhedra, snub uniform polyhedra, deltahedra (polyhedra consisting only of equilateral triangles), and polychora; with animations, still graphics, and some taxonomic data (vertices, edges, faces, polygons, radii, and more). Mobius
...more>>
 Polyhedra Sketches  Bill Finzer, Key Curriculum Press
Sketches showing the platonic solids in true perspective. You have control over the placement of the picture plane, the station point, and the horizon. An animation button rotates the figure. Some of the sketches show in 3D if you have a pair of 3D glasses.
...more>>
 Polyhedron: An application in solid geometry  Stelian Dumitrascu
Software based on "deductionfree geometry," which allows the user to perform various actions upon solids as if holding these solids in your hands. It simulates a number of tools, such as the ruler, protractor, setsquare, compass, bisector, saw, and eraser.
...more>>
 Polymake  Ewgenij Gawrilow and Michael Joswig
A tool for the algorithmic treatment of polytopes and polyhedra. Polymake has
C++ and perl interfaces that allow the user to combine the wealth of available methods with his/her own implementations.
...more>>
 Polynomials, Rational Functions  Dave Rusin; The Mathematical Atlas
A page reserved for the analytic study of polynomial functions studied in calculus classes. History; applications and related fields and subfields; textbooks, reference works, and tutorials; software and tables; selected topics; other web sites with this
...more>>
 Polyominoes  Kevin Gong
Information and Polyominoes software to download. A polyomino is a piece made up entirely of squares connected edgetoedge. For example, a domino is a polyomino with 2 squares. In this program, you can use pentominoes, tetrominoes, trominoes, hexominoes,
...more>>
 Polytopes and Polyhedra  Dave Rusin; The Mathematical Atlas
A short article designed to provide an introduction to geometric objects made from straight pieces: polygons, polyhedra, and generalizations. Applications and related fields and subfields; textbooks, reference works, and tutorials; software and tables;
...more>>
 Polytopes, Zonohedra, Zonotiles, Mathematica notebooks  Russell Towle
Some of the author's endeavors in geometry, including studies of zonohedra, polyhedra, spacefillings, polytopes in higher space, and the discovery of new types of polyhedra and spacefillers. Mathematica notebooks are provided which create these kinds
...more>>
 Ponder This  IBM Research
Match wits with the minds in IBM Research, who post a new puzzle every month (some suggested by users at large), and welcome your solutions. Archives of previous challenges.
...more>>
 POP Mathematics (Mathematics Archives)  University of Tennessee, Knoxville (UTK)
Did you ever wonder what made your teacher get so excited about some topic in Mathematics? On this page the Math Archives site collects items about Mathematics that may explain this weird behavior. Also included on this page are links they couldn't figure
...more>>
 Popular Science
Browse the science and technology news magazine's math articles, where stories have included "Mathematician Cracks The Code for Making Hollywood Blockbusters," "Japanese Super Computer Calculates Pi To The 2.5 Trillionth Decimal Point," "Math, Art, and
...more>>
 Population Index 19861998  Office of Population Research, Princeton University
The primary reference tool to the world's population literature, presenting an annotated bibliography of recently published books, journal articles, working papers, and other material on population topics. It covers all fields of interest to demographers,
...more>>
 The Position of the Sun  Dave Rusin; The Mathematical Atlas
A computer program to calculate the position of the sun, with an article describing the calculation of the apparent sun position in local coordinates for an earth observer: notation; solution; removing the effect of one variable and simplifying the solution;
...more>>
 Positive and negative Euler characteristic (Geometry and the Imagination)  Conway, Doyle, Gilman, Thurston; The Geometry Center
A symmetry pattern on the sphere always gives rise to a quotient orbifold with positive Euler characteristic. In fact, if the order of symmetry is k, then the Euler characteristic of the quotient orbifold is 2/k, since the Euler characteristic of the
...more>>
 The PostCALC Project  Duke University
The PostCALC Project is a branch of the Connected Curriculum Library that presents interactive, mathematicallybased modules designed for high school students who have finished a yearlong course in calculus. These modules, each appropriate for several
...more>>
 The postIMO97 web page  Olimpíada Matemática Argentina
Problems and results from the math olympics held in Argentina in July, 1997. Available in English and Spanish, with problems also in French, Russian, German, and a host of other languages.
...more>>
 Postulates and Theorems of Boolean Algebra  Julie Kenrow; Santa Clara University, Santa Clara, CA
Five postulates (identity, complement, commutative law, associative law, distributive law); and six theorems. Supplementary material for a course in electrical engineering (Logic Design).
...more>>
 Potential Theory  Dave Rusin; The Mathematical Atlas
A short article designed to provide an introduction to potential theory, the mathematical treatment of the potentialenergy functions used in physics to study gravitation and electromagnetism. If some electrically charged particles are distributed in
...more>>
 POVRay  Persistence of Vision Raytracer Pty. Ltd
The Persistence of Vision RayTracer creates threedimensional, photorealistic images using a rendering technique called raytracing, which calculates an image of a scene by simulating the way rays of light travel in the real world. Download the latest
...more>>
 
