Adam McEwen’s escalator stairs, disassembled and scattered on Gagosian Gallery’s floor are readymades related to movement, though unlike Duchamp’s spinnable bike wheel mounted on a stool, they’re solidly in place. Dedicated to mass transit, their egalitarian nature contrasts an upside down image of a stretch limo, printed on cellulose sponge and hung on the wall behind. (On view at Gagosian Gallery’s 980 Madison Ave 5th floor gallery).