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

November 14, 2017

Ear on the Sky


Green Bank, West Virginia, 1977.

Photo by I.Peterson

November 12, 2017

Hypercube Model


Constructed from seven square cylinders, each made from a strip of four squares, this model of an unfolded hypercube, created by Thomas F. Banchoff, collapses into a flat, two-dimensional configuration.


Photos by I. Peterson

November 11, 2017

Crinkled Torus


Crinkled torus by William T. Webber.


A properly creased, rectangular sheet can be turned into a crinkled torus shape.


Photos by I. Peterson; model by William T. Webber.

November 10, 2017

Shoreline Reflection


Winona, Minnesota, 2008.


Photos by I. Peterson


November 9, 2017

Wooster Autumn


Kauke Hall. College of Wooster, Wooster, Ohio, 2009.

Photo by I. Peterson

November 7, 2017

Potomac View


View of the Potomac River from the lawn of George Washington's Mount Vernon. Mount Vernon, Virginia, 1981.

Photo by I. Peterson

November 5, 2017

Silver Leaves


Bloor Parkette (southeast corner of Bloor Street West and Spadina Avenue), Toronto, Ontario, 2009.


See also "Leaf on Leaf."

Photos by I. Peterson

November 4, 2017