Intangibility comes in many forms. It’s the force holding the thousands of straight pins in their cube formation in a sculpture by Tara Donovan. It’s the jostles and jerks of the subway that directed William Anastasi’s hand in making Untitled (Subway Drawings). It’s the strobe lights Rosalind Nashashibi and Lucy Skaer shot into the darkened galleries at the Metropolitan Museum of Art: There’s antiquity, now it’s gone. All these, plus pieces that involve hypnosis, infidelity, fish, and staring, are here, and nowhere. (Henry Art Gallery, 15th Ave NE and NE 41st St,, 11 am–9 pm, $10 suggested, through May 5)