An interactive public art exhibit from the ever-quirky polymath Miranda July, called Eleven Heavy Things, lands on the central lawn of Union Square Park this Saturday. In classic July style, the eleven fiberglass tablets, pedestals, and “freestanding abstract headdresses” are both comical and thought-provoking. One pedestal, with room for two participants, is captioned: “We don’t know each other, we’re just hugging for the picture.” (Union Square East, nr. 16th St.; through October 3.)