If you are observant enough, careful enough, curious enough, there is an entire world underfoot waiting to be discovered. It is a world nestled in ours but unlike ours—an illusionistic wonderland etched in chalk by Ann Arbor’s neighborhood “chalk man.” It’s a reality only visible to those who are looking for it amongst the jumble of the mundane. But in this world, if you are lucky enough to stumble across it, one rule remains the same as ours: things will not, cannot, last forever. Artist David Zinn says that’s the point.