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"Shells 532," by Chaim GoodmanStrauss, University of Arkansas (http://mathbun.com/main.php)There are seven infinite families, and seven more individual types of discrete symmetrical patterns on the sphere. A pattern of type 532 is shown; there are three kinds of gyration points in the patterna 5fold, a 3fold, and a 2fold gyration point are marked. This image is from "The Symmetries of Things", by John H. Conway, Heidi Burgiel and Chaim GoodmanStrauss (AK Peters, 2008).Jan 31, 2008


"Calla Lily 32 infinity," by Chaim GoodmanStrauss, University of Arkansas (http://mathbun.com/main.php)The group SL_2(Z) acts on the hyperbolic plane discretely, producing patterns of symmetry type 23 infinity, such as the one shown here. Similarly, the 2fold cover GL_2(Z) acts with symmetry type *23 infinity. This image is from "The Symmetries of Things", by John H. Conway, Heidi Burgiel and Chaim GoodmanStrauss (AK Peters, 2008).Jan 31, 2008


"The Hexacosm," by Chaim GoodmanStrauss, University of Arkansas (http://mathbun.com/main.php)This spaceship is flying about in the universal cover of the hexacosm, one of the ten, closed, flat threemanifolds. Equivalently, the pattern is one of the ten discrete cocompact symmetry types of Euclidean space that does not have any fixed points. The type here is (6_1 3_1 2_1) in the ThurstonConway fibrefold notation. This image is from "The Symmetries of Things", by John H. Conway, Heidi Burgiel and Chaim GoodmanStrauss (AK Peters, 2008).Jan 31, 2008


"Tube *X," by Chaim GoodmanStrauss, University of Arkansas (http://mathbun.com/main.php)This strange image is just of a distorted but perfectly sensible regular pattern in the Euclidean plane, of type *X. A complicated image like this can be built from simple steps, and can be expressed in just a single formula; the colors of the initial pattern are from the values of
f(x,y) = cos(x  cos(y+a))cos(y  cos(x+a)), with
a = pi/5.  Chaim GoodmanStrauss
Jan 31, 2008


"The Regular Hendecachoron," computer model by Carlo Sequin, University of California, Berkeley.This hendecachoron (a literal translation of "11cell" into Greek) is a regular, selfdual, 4dimensional polytope composed from eleven nonorientable, selfintersecting hemiicosahedra. This object also has 11 vertices (shown as spheres), 55 edges (shown as thin cylindrical beams), and 55 triangular faces (shown as cutout frames). Different colors indicate triangles belonging to different cells. This intriguing object of high combinatorial symmetry was discovered in 1976 by Branko Grünbaum and later rediscovered and analyzed from a group theoretic point of view by geometer H.S.M. Coxeter. Freeman Dyson, the renowned physicist, was also much intrigued by this shape and remarked in an essay: "Plato would have been delighted to know about it." The hendecachoron has 660 combinatorial automorphisms, but these can only show themselves as observable geometric symmetries in 10dimensional space or higher. In this image, the model of the hendecachoron is shown with a background of a deep space photo of our universe, to raise the capricious question, whether this 10dimensional object might serve as a building block for the 10dimensional universe that some stringtheorists have been postulating.
A more detailed description and visualization of the 11Cell, describing its construction in bottomup as well as in top down ways, can be found in a paper by Sequin and Lanier: “Hyperseeing the Regular Hendecachoron”. There are additional images and VRML models for interactive inspection here.  Carlo Sequin Sep 04, 2007


"Fiddler Crab, opus 446," by Robert J. Lang. Medium: One uncut square of Origamido paper, composed and folded in 2004, 4". Image courtesy of Robert J. Lang. Photograph by Robert J. Lang.The intersections between origami, mathematics, and science occur at many levels and include many fields of the latter. Origami, like music, also permits both composition and performance as expressions of the art. Over the past 40 years, I have developed nearly 600 original origami compositions. About a quarter of these have been published with folding instructions, which, in origami, serve the same purpose that a musical score does: it provides a guide to the performer (in origami, the folder) while allowing the performer to express his or her own personality through interpretation and variation.
I'm especially pleased with this model, which involves a combination of symmetry with one distinctly nonsymmetric element. The base is quite irregular, but its asymmetry is mostly concealed. The crease pattern is here.
 Robert J. LangSep 04, 2007


"Allosaurus Skeleton, opus 326," by Robert J. Lang. Medium: 16 uncut squares of Wyndstone "Marble" paper, 24". Image courtesy of Robert J. Lang. Photograph by Robert J. Lang.This model was inspired by the brilliant Tyrannosaurus Rex of the late Issei Yoshino.
The intersections between origami, mathematics, and science occur at many levels and include many fields of the latter. Origami, like music, also permits both composition and performance as expressions of the art. Over the past 40 years, I have developed nearly 600 original origami compositions. About a quarter of these have been published with folding instructions, which, in origami, serve the same purpose that a musical score does: it provides a guide to the performer (in origami, the folder) while allowing the performer to express his or her own personality through interpretation and variation.
 Robert J. LangSep 04, 2007


"African Elephant, opus 322," by Robert J. Lang. Medium: One uncut square of watercolor paper, composed and folded in 1996, 8". Image courtesy of Robert J. Lang. Photograph by Robert J. Lang.The intersections between origami, mathematics, and science occur at many levels and include many fields of the latter. Origami, like music, also permits both composition and performance as expressions of the art. Over the past 40 years, I have developed nearly 600 original origami compositions. About a quarter of these have been published with folding instructions, which, in origami, serve the same purpose that a musical score does: it provides a guide to the performer (in origami, the folder) while allowing the performer to express his or her own personality through interpretation and variation.
 Robert J. LangSep 04, 2007


"Tree Frog, opus 280," by Robert J. Lang. Medium: One uncut square of Origamido paper, composed in 1993, folded in 2005, 5". Image courtesy of Robert J. Lang. Photograph by Robert J. Lang.The intersections between origami, mathematics, and science occur at many levels and include many fields of the latter. Origami, like music, also permits both composition and performance as expressions of the art. Over the past 40 years, I have developed nearly 600 original origami compositions. About a quarter of these have been published with folding instructions, which, in origami, serve the same purpose that a musical score does: it provides a guide to the performer (in origami, the folder) while allowing the performer to express his or her own personality through interpretation and variation.
 Robert J. Lang
Sep 04, 2007


"Bull Moose, opus 413," by Robert J. Lang. Medium: One uncut square of Nepalese lokta, composed and folded in 2002, 6". Image courtesy of Robert J. Lang. Photograph by Robert J. Lang.The intersections between origami, mathematics, and science occur at many levels and include many fields of the latter. Origami, like music, also permits both composition and performance as expressions of the art. Over the past 40 years, I have developed nearly 600 original origami compositions. About a quarter of these have been published with folding instructions, which, in origami, serve the same purpose that a musical score does: it provides a guide to the performer (in origami, the folder) while allowing the performer to express his or her own personality through interpretation and variation.
 Robert J. Lang
Sep 04, 2007


"Night Hunter, opus 469," by Robert J. Lang. Medium: One uncut square of Korean hanji, composed and folded in 2003, 18". Image courtesy of Robert J. Lang. Photograph by Robert J. Lang.The intersections between origami, mathematics, and science occur at many levels and include many fields of the latter. Origami, like music, also permits both composition and performance as expressions of the art. Over the past 40 years, I have developed nearly 600 original origami compositions. About a quarter of these have been published with folding instructions, which, in origami, serve the same purpose that a musical score does: it provides a guide to the performer (in origami, the folder) while allowing the performer to express his or her own personality through interpretation and variation.
 Robert J. Lang
Sep 04, 2007


"Persian Rug (Recursian I)," by Anne M. Burns (Long Island University, Brookville, NY)An applet uses a recursive (repeatedly applied) procedure to make designs that resemble Persian rugs. You may choose 3 parameters a, b and c, and one of 6 color palettes each consisting of 16 colors numbered 0 through 15. The parameter c ( 0 through 15) represents an initial color. A 257 by 257 square is drawn in the color numbered c. Label the 4 corner colors c1, c2, c3 and c4 (at the initial stage they will all be c). then a new color is determined by the formula a + (c1+c2+c3+c4)/b mod 16 and a horizontal and vertical line that divide the original square into 4 new squares are drawn in the new color. The procedure is repeated recursively until all the pixels are filled in. Read more about "Persian" Recursians, enter the parameters and click on Draw rugs, and download a Windows Program that makes "Persian" rugs, at http://myweb.cwpost.liu.edu/aburns/persian/persian.htm.  Anne M. Burns (Long Island University, Brookville, NY)Jun 01, 2007


"Fractal Scene I," by Anne M. Burns"Mathscapes" are created using a variety of mathematical formulas. The clouds and plant life are generated using fractal methods. The mountains are created using trigonometric sums with randomly generated coefficients; then, using 3D transformation, they are projected onto the computer screen. Value and color are functions of the dot product of the normal to the surface with a specified light vector. See the Gallery of "Mathscapes and find citations for my articles on modeling trees, plants and mountains, and on "blending and dithering," at http://myweb.cwpost.liu.edu/aburns/gallery/gallery.htm.  Anne M. Burns (Long Island University, Brookville, NY)Jun 01, 2007


"Imaginary Garden," by Anne M. Burns (Long Island University, NY)"Mathscapes" are created using a variety of mathematical formulas. The clouds and plant life are generated using fractal methods. The mountains are created using trigonometric sums with randomly generated coefficients; then, using 3D transformation, they are projected onto the computer screen. Value and color are functions of the dot product of the normal to the surface with a specified light vector. See the Gallery of Mathscapes and find citations for my articles on modeling trees, plants and mountains, and on "blending and dithering" at http://myweb.cwpost.liu.edu/aburns/gallery/gallery.htm.  Anne M. Burns (Long Island University, Brookville, NY)Jun 01, 2007


"Lilacsan Imaginary Inflorescence," by Anne M. Burns (Long Island University, Brookville, NY)"Inflorescence" is the arrangement of flowers, or the mode of flowering, on a plantsometimes simple and easily distinguishable, sometimes very complex. "Lilacs" is an example of an imaginary inflorescence that I have created using computer graphics techniques. Two Java applets allow users to see and draw purely imaginary inflorescences at various stages using the recursive (repeatedly applied) functions. Download the code from either applet, and see photographs of real inflorescences several imaginary inflorescences, at http://myweb.cwpost.liu.edu/aburns/inflores/inflores.htm.  Anne M. Burns (Long Island University, Brookville, NY)Jun 01, 2007


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