December 31, 2017

Squiggle on the Wall


A Minute of My Time by Micah Lexier. Agnes Etherington Art Centre, Queen's University, Kingston, Ontario, 2006.

Photo by I. Peterson

December 30, 2017

December 29, 2017

Aristotelian Cosmology


In this 1545 depiction of Aristotelian cosmology, Petrus Apianus shows a stationary Earth at the center of the universe, surrounded by seven concentric "crystalline" spheres, which carry the sun, the moon, and the planets.

Reproduced from the collections of the Library of Congress

December 28, 2017

House Icicles


Meadville, Pennsylvania, 2010.


Photo by I. Peterson

December 27, 2017

Optimizing Path


Foot traffic creates an optimizing path that takes into consideration obstacles and slope. Washington, D.C., 2016.


Photo by I. Peterson

December 26, 2017

Ivied Column


Milan, Italy, 2010.

Photo by I. Peterson

December 25, 2017

December 24, 2017

Lights on Old and New


Lighting up vehicles, old and new. Santa Fe, New Mexico, 2015.

Photo by I. Peterson

December 23, 2017

Hanging Star


Street decoration. Washington, D.C., 2017.

Photo by I. Peterson

December 22, 2017

Frost Spikes


Columbia, Missouri, 1981.

Photo by I. Peterson

December 21, 2017

Torus Candle



Street decoration, Montreal, Quebec, 2006.

Photo by I. Peterson

December 20, 2017

December 19, 2017

Grid Shadows


Washington, D.C., 2017.

Photo by I. Peterson

December 18, 2017

Red Leaf


Washington, D.C., 2017.

Photo by I. Peterson

December 17, 2017

December 16, 2017

Fan Tail


Washington, D.C., 2017.

Photo by I. Peterson

December 15, 2017

December 14, 2017

Stacked Stone Sphere


Stacked Stone Sphere by Devin Devine. Brookside Gardens, Silver Spring, Maryland, 2017.

Photo by I. Peterson

December 13, 2017

Crystal Christmas


Exhibit of contemporary Christmas art. Milan, Italy, 2010.

Photo by I. Peterson

December 12, 2017

Frosted Niagara


Niagara Falls, Ontario, 1980.

Photo by I. Peterson

December 11, 2017

Three Ways


Ottawa, Ontario, 1974.

Photo by I. Peterson

December 10, 2017

Icicle Time


Johnstown, Pennsylvania, 1981.


Photos by I. Peterson

December 9, 2017

Tree Row


Longwood Gardens, Kennett Square, Pennsylvania, 1978.

Photo by I. Peterson

December 8, 2017

Burst Column


Burst of Joy by Harold Kimmelman. Philadelphia, Pennsylvania, 2000.

Photo by I. Peterson

December 7, 2017

Face of Pittsburgh


Union Station, Pittsburgh, Pennsylvania, 2008.

Photo by I. Peterson

December 6, 2017

Prairie Sun


Tucker Prairie, Callaway County, Missouri, 1980.

Photo by I. Peterson

December 5, 2017

Snow Bench


Trinity College School, Port Hope, Ontario, 1979.

Photo by I. Peterson

December 3, 2017

Old Cemetery


Old Jewish Cemetery, Prague, Czechoslovakia, 1985.

Photo by I. Peterson

December 2, 2017

Oval with Points


Oval with Points by Henry Moore. Princeton University. Princeton, New Jersey, 2006.

Photo by I. Peterson

December 1, 2017

Shore Birds


Perce Rock, Gaspe Peninsula, Quebec, 1974.

Photo by I. Peterson

November 30, 2017

Fake Flake


Snowflake street decoration with incorrect octagonal (rather than hexagonal) symmetry. Washington, D.C., 2017.

Photo by I. Peterson

November 29, 2017

Giant Steps


Giant Steps by Enrico Riley. Virginia Museum of Fine Arts, Richmond, Virginia, 2017.

Photo by I. Peterson

November 28, 2017

Trapezoid Stool


"Rotating Shapes" stool, created by Mary Elizabeth Yarborough. Exploratorium, San Francisco, California, 2013.

See also "Triangle Seat."

Photo by I. Peterson

November 27, 2017

Torus Coloring


Seven-color tori knit by sarah-marie belcastro (left) and Carolyn Yackel (right). Mathematical Art Exhibit, MAA MathFest, San Jose, California, 2007.

Photo by I.Peterson

November 26, 2017

November 25, 2017

Gold Carpet


A tree-centered distribution of leaves. What can you say about the conditions under which the leaves fell? Washington, D.C., 2017.

Photo by I. Peterson

November 24, 2017

Sawdust Distributions


What caused this pattern of spaced sawdust clumps, diminishing in size to the left? Washington, D.C., 2017.


More clues.

Photos by I. Peterson

November 23, 2017

Sweeping Up


Gargoyle, Wells Cathedral, England, 1975.

Photo by I. Peterson

November 22, 2017

Wintry Slope


Kingston, Ontario, 1974.

Photo by I. Peterson

November 21, 2017

Wood Stain


Sarah Lawrence College, Bronxville, New York, 2009.


Photo by I. Peterson

November 20, 2017

November 18, 2017

White Yellow Black


Building decoration, Toronto, Ontario, 2006.

Photo by I. Peterson

November 17, 2017

Golden Triangle


Banner with logo of the Golden Triangle Business Improvement District: Moebius strip,or not?. Washington, D.C., 2017.

See also "Impossible Logo."

Photo by I. Peterson

November 16, 2017

Gold Tree


Gunston Hall, Mason Neck, Virginia, 1982.

Photo by I. Peterson

November 15, 2017

Mace Moebius


Mace Moebius by Charles O. Perry. Crystal City, Virginia, 2000.

See also "Mobius Continuum" and "Moebius Eclipse." 

Photo by I. Peterson