According to its two crackerjack curators, Laura Hoptman and Peter Eleey, "Strange Powers," their group show about spirituality, magic spells, aura photography and the like, is an attempt to "explore the transportive power of art." They go an audacious step further and assert that art has the ability to change the world. This isn't a review of their wonderfully wonky show, it's a reality check. Are Hoptman and Eleey right? Can art change the world?