At any rate, Piano believes that interior light should breathe as exterior light does, so photovoltaic cells embedded in the glass constantly adjust available light so that you don’t suffer steady-illumination fatigue. Movement matters in other ways. For his structure to enter the dance already started by the happily functioning elements of Millennium Park, Piano designed an elevated 620-foot-long walkway that swoops over Monroe Street and “wires” the museum to the park: its stainless-steel cladding greets the material of the Music Pavilion and the Bean. Pause at a certain point on the ramp and you get a panoptic view of human experience. South is the art tabernacle that awaits your reverence. North you see Plensa’s colorful slabs, Kapoor’s shimmering punched pillow, and Gehry’s gulls. Ranked east are the elegant, alert overseers constructed after the fire, and west — beyond the lush expanse of a now-vivacious Grant Park — is the great lake. The self-defining human artifice of art and architecture, the natural order of fields and lake — they’re all right there. Then look down and see the world of hard industry, the remains of a Chicago that once was but exists now like glassed-over excavations of Etruscan dwellings you see in Italian cities: rail lines, with a few dilapidated Amtrak coaches finally taking retirement.