


A spiral is formed as square structures rotate along the span of the High Trestle Trail bicycle bridge in central Iowa. The 41 steel structures that arch over the bridge were originally designed to represent the support cribs historically used in coal mines. Photo by M. E. (Murphy) Waggoner (Simpson College). 
Anne Burns (Long Island University) received Third Place for "Circles on Orthogonal Circles" in the 2011 Mathematical Art Exhibition Awards at the 2011 Joint Mathematics Meetings in New Orleans. 
Weirs on the Avon River in Bath, England, look like nested parabolas. Photo taken by Karl Schmerbauch. 



Hyperbolic Isometry in the Disk with Symmetrical Cuts Model from bulatov.org. This is a cool animation. At each moment, this movie shows you a tiling of the hyperbolic plane by pentagons, four meeting at each corner, mapped onto a disc with four slits cut out. This mapping is conformal, meaning that it preserves angles. As time passes, the hyperbolic plane rotates and we see this crazy movie. (h/t John Baez) 
Forest pi found by Kenneth Vincent in Pacific Spirit Park, Vancouver, BC 
A tile mural at the Mathematical Sciences Research Institute in Berkeley, Calif., includes a pi tile. 

Margaret Kepner, independent artist, received First Prize Award for her work, "Magic Square 25 Study" at the 2011 Joint Mathematics Meetings in New Orleans. 
"Magic Square 25 Study" (2010) is an archival inkjet print. Kepner described the work in the exhibition catalog: "Magic squares are numerical arrays that have substructures with constant sums. This design is based on a magic square of order 25, containing the numbers from 0 to 624. Each row, column, and main diagonal sums to the 'magic constant' of 7800. The numbers in the magic square are represented by a visual base5 system: four concentric squares serve as the 1, 5, 25, and 125 places, while shades of grey stand for the numerals 0 to 4. Coding the numbers into their base5 versions yields a pattern of 625 unique, nestedsquares in shades of grey. This particular magic square also has a substructure of 25 minisquares of size 5. Each of these minisquares is "magic" (although the numbers are not consecutive), with rows, columns, and diagonals summing to 1560. In addition, certain other groups of 5 squares add up to 1560. Examples are the quincunx and the plussign s hapes (when fully contained in a m inisquare). The colored accents are used to indicate a few of these 'magic' substructures." 