Penrose Tiles
Penrose was not the first to discover aperiodic
tilings, but his is probably the most well-known.
In its simplest form, it consists of 36- and 72-degree rhombi,
with "matching rules" forcing the rhombi to line up
against each other only in certain patterns. It can also be formed
by tiles in the shape of "kites" and "darts" or even by deformed
chickens (see the "perplexing poultry" entry below).
Part of the interest in this tiling stems from the fact
that it has a five-fold symmetry impossible in
periodic crystals, and has been used to explain the structure of certain
"quasicrystal" substances.
- Ancient
Islamic Penrose Tiles. Peter Lu uncovers evidence that the
architects of a 500-year-old Iranian shrine used Penrose tiling to lay
out the decorative patterns on its archways. From Ivars Peterson's
MathTrek.
- Aperiodic
tiling and Penrose tiles, Steve Edwards.
- The
Art and Science of Tiling.
Penrose tiles at Carleton College.
- Cellular
automaton run on Penrose tiles, D. Griffeath.
See also Eric
Weeks' page on cellular automata over quasicrystals.
- Clusters and
decagons, new rules for using overlapping shapes to construct
Penrose tilings. Ivars Peterson, Science News, Oct. 1996.
- Five-fold symmetry in crystalline quasicrystal lattices, Donald L. D. Caspar and Eric Fontano.
- Gallery of interactive on-line geometry.
The Geometry Center's collection includes programs for generating
Penrose tilings, making periodic drawings a la Escher in the Euclidean
and hyperbolic planes, playing pinball in negatively curved spaces,
viewing 3d objects, exploring the space of angle geometries, and
visualizing Riemann surfaces.
- Goldene
Schnittmuster. Article in German on Penrose tiling and related topics.
- Irrational
tiling by logical quantifiers. LICS proceedings cover art by Alvy Ray Smith, based on the Penrose tiling.
- Java Penrose Tiler, Geert-Jan van Opdorp.
Shuxiang Zeng has written another Java applet to play with Penrose tiles.
- Kadon Enterprises,
makers of games and puzzles including polyominoes and Penrose tiles.
- Mathematical imagery by Jos Leys.
Knots, Escher tilings, spirals, fractals, circle inversions, hyperbolic
tilings, Penrose tilings, and more.
- Making your own set of Penrose rhombs, N. Casey.
- Math, Penrose,
Plato, and Pentagrams. Philip Marsh claims that Penrose's pentagonal
tilings connect him to the numerology of the Pythagoreans.
- Dave Molnar's research
on non-Euclidean symmetry and long-range order, Penrose and substitution
tilings, L-systems, and cellular automata.
- Non
periodic tiling of the plane.
Including Penrose tiles, Pinhweel tiling, and more. Paul Bourke.
- Ozbird Escher-like tessellations
by John Osborn, including several based on Penrose tilings.
- Patterns within
rhombic Penrose tilings. Stephen Collins' program "Bob" generates
these tilings and explores the patterns formed by geodesic walks in them.
- Penescher
tiling, Marc Pickett.
- Penrose
mandala and five-way Borromean rings.
- Das Penrose Parkett. (In German.)
- Penrose
Pavers in Penngrove. Pat Walp shows off a path of concrete Penrose
rhombs he made for his garden.
- Penrose quilt on a
snow bank, M.&S. Newbold. See also
Lisbeth
Clemens' Penrose quilt.
- The penrose
tile and the golden mean: towards hyperdimensional intergeometry.
- Penrose-tiled
lace doily.
- Penrose-tiled swallow
- Penrose tiles
and how their visualization leads to strange looks from priests and
small children. Drew Olbrich.
- Penrose
tilings and quasitiler.
- Penrose
Tilings at Miami Univ.
- Penrose tiles and worse. This article from Dave Rusin's known math pages discusses the difficulty of correctly placing tiles in a Penrose tiling, as well as describing other tilings such as the pinwheel.
- Penrose
Tiles entry from E. Weisstein's treasure trove.
- Penrose tiles at Storey Hall, RMIT, Melbourne, Australia.
See also
Aperiodic
Tiling, Penrose Tiling and the Generation of Architectural Forms,
M. J. Ostwald, Nexus '98.
- Penrose tilings and the golden mean, K. Wiedman.
See also this closely related Wheaton
college course project.
- Penrose-Wang
tilings. Tony Smith
describes some of the mathematics behind these aperiodic tilings,
somehow leading to the concluding question
"Can musical sequences also simulate the operation of any Turing machine?"
- Penrose's
influence on Escher.
- Perplexing poultry
Penrose pieces from pentaplex. Also comes with alien space dogs.
- Pentagonal coffee table with rhombic bronze casting related to the Penrose tiling, by Greg Frederickson.
- Pretty
Penrose picture, J. Beale, Stanford.
- Quasicrystals
and color symmetry. Ron Lifshitz provides a light introduction to
the symmetry of periodic and aperiodic crystals, and the complications
introduced by including permutations of colors in a coloring as part of
a symmetry operation. His
publication
list includes more technical material on the same subject.
- QuasiG
freeware Windows Penrose tiling program.
- Quasitiler image, E. Durand.
- Saints
Among Us.
Anna Chupa
makes kaleidoscopic photomontages based on the geometry of the Penrose tiling.
- Shawn's
mathematical gallery. Penrose tilings,
Newton-iteration convergence-domain fractals,
Schlegel diagrams of four-dimensional polyhedra,
and more.
- Some planar tilings
generated by the lattice projection method
(of which the Penrose tiling is a special case)
by Andrew Lewis, Queens U.
- Tessellations,
a company which makes Puzzellations puzzles, posters, prints, and
kaleidoscopes inspired in part by Escher, Penrose, and Mendelbrot.
- Three-color the Penrose tiling?
Mark Bickford asks if this tiling is always three-colorable.
Ivars
Peterson reports on a new proof by Tom Sibley and Stan Wagon
that the rhomb version of the tiling is 3-colorable;
A proof of 3-colorability for kites and darts
was recently published by Robert Babilon
[Discrete Mathematics 235(1-3):137-143, May 2001].
This is closely related to my page on line
arrangement coloring, since every Penrose tiling is dual to
a "multigrid", which is just an arrangement of lines in parallel families.
But my page only deals with finite arrangements, while Penrose tilings are
infinite.
- Tilings.
Lecture notes from the Clay Math Institute, by Richard Stanley and
Federico Ardila, discussing polyomino tilings, coloring arguments for
proving the nonexistence of tilings, counting how many tilings a region
has, the arctic circle theorem for domino tilings of diamonds,
tiling the unit square with unit-fraction rectangles, symmetry groups,
penrose tilings, and more. In only 21 pages, including the annotated
bibliography. A nice but necessarily concise introduction to the subject.
(Via Andrei Lopatenko.)
- Toilet
paper plagiarism. A big tissue company tries to rip off Sir Roger P.
- The
trouble with five. Craig Kaplan explains why five-fold symmetry
doesn't work in regular plane tilings, but does work for the Penrose tiling.
- Voronoi
diagram of a Penrose tiling (rhomb version), Cliff Reiter.
- Z2
section of a Penrose tiling.
Robbie Robinson
explains his work on the dynamical theory of tilings.
From the Geometry Junkyard,
computational
and recreational geometry pointers.
Send email if you
know of an appropriate page not listed here.
David Eppstein,
Theory Group,
ICS,
UC Irvine.
Semi-automatically
filtered
from a common source file.