It is hard to imagine a subject less worthy of artistic celebration than the ubiquitous blobs of squished chewing gum that dot city sidewalks around the world, but Christian Marclay has photographed thousands of them on his daily walks through London and has edited those images into a lively, humorous stop-motion animation. Through careful sequencing, Marclay allows the banal spots to merge and divide like cells, dance playfully with one another, and explode into a cosmic constellation.