Mathematical forms are no longer unusual sights at the annual International Snow Sculpture Championships in Breckenridge, Colo. For 7 years, mathematician Stan Wagon of Macalester College in St. Paul, Minn., and his team have carved huge blocks of snow into graceful geometric shapes.
This year, the team took on a particularly challenging, intricately convoluted form—one that incorporated the intriguing surface known as a Möbius strip.