Light and movement are everything, for viewers of the 40-foot kinetic mobile sculpture by artist Tim Prentice installed in March in the atrium of the Ann and Robert H. Lurie Biomedical Engineering Building on North Campus. The mobile sculpture presents changing forms as a ribbon of reflective aluminum plates moves gently in a variety of soft curves in response to the slightest currents of air in the two-story space. The appearance also changes due to the characteristics of the natural light entering the space along the long glass wall at both levels and the angle of the sun. (Photo by Martin Vloet, U-M Photo Services)