Maps are constantly being re-written to reflect new political boundaries, and improved map making techniques. Blobby sketches jotted down by early explorers have given way to satellite photos that don't leave an inch of mystery. A new exhibit at the University of Minnesota celebrates the vast array of maps that serve as a timeline of sorts, charting human understanding of the world and universe. The Weisman exhibit also includes new maps, commissioned by artists. Curator Rob Silberman says he got the idea for a map show from current events.