Vija Celmins has been an admired artist for more than fifty years, and for most of that time critics have struggled to explain the elusive poignancy and staying power of her work. In an art world that rewards noisy assertion and the avid annexation of wall space, her work is thoughtful, modest in scale, mostly black-and-white. And while much contemporary art prides itself on being difficult, even opaque, Celmins’s paintings and drawings of night skies and oceans are eye-pleasing and generous in a way that keeps them broadly appealing, even as they contend with weighty questions about the mechanics and consequences of representation. All this makes her work hard to encompass in the current language of art. Looking at her pairings of apparently identical rocks, the word that floats to mind is not “simulacrum” but “sublime.”