Men, women, and children freckle the landscape as dusk lays a cool sheet over the park. A secret science passes from light to leaf to branch to air, an alchemy that tames the heat, dulls the glare of sun. Fireflies twinkle in the dark tangle of growth under a row of hedges. The woman walks slowly toward the monument that dominates the park. The glow of the silver sphere sings to all who wander near. Like a moon, it glitters through the trees, it hovers like a dream of drowning.

The Unisphere rises out of a broad basin of concrete. The rim of the arena is outlined with a low granite wall. If the woman were to lie down and press her cheek to the pale pavement she would see the bend of the earth in the slope of the shallow crater. If she were to lie flat directly under the steel sculpture, it would be like lying on the bottom of the world. Three girls brace one foot and then the other against the wall to lace up their roller skates. Copper pipes grow like swamp iris every three or four feet, each releasing a stream of cool water that trickles down the sides of the cement bowl. A toddler with eyes as solemn as a cat dips the toe of her sandal in the drip pool and watches the dampness turn her shoe a darker brown.

The sculpture is of the planet Earth, like a geography class globe, with the continents soldered from vast plates of steel, and a filigree of narrower land masses linking Africa to Europe to Asia. If the woman were to stand at her full height and stretch out her fingers, she could not touch the tip of South America; the base of the monument holds the planet far above, in permanent suspension. The oceans and the seas exist in the sculpture as patches of empty space. On an overcast day, the clouds in the sky drift from continent to continent, like lost ships.

The woman is not lying on her back as though she had fallen into the center of the earth. She stands silent, near the Unisphere, and watches the skaters, the joggers, the skateboarders, the strollers. A family group from India has brought a picnic supper and they settle near a grove of young maples. The women look like petals fluttering to the ground, in their rose-colored saris. The children dart about like sparrows, and the men, in their formal clothes, cluster to one side of the gathering. Their heads are bent together, as intent as judges.

Not far from the wide plaza where the Unisphere is anchored, the movement of two people catches the woman's eye. First, a boy runs into her field of vision. He is tall, long-boned, about 10 years old, no longer a child, but only a sketch of the man he'll become. He is shirtless, wearing a pair of shorts made with quick scissor strokes from last year's school pants. Elbows tucked in, he runs with the grace of a pup, pleased with himself. He twists around, still running, to look over his shoulder at his mother, who chases him. She moves easily, too, a woman who will not be held back, who runs to win. Now skipping closer to her son, her facial features are distinct-she is still quite young, not yet 40. She laughs, and her hair tumbles forward as she lunges with a last push to tag her son. He could get away-- he could out-run a rabbit-- but he leans into her scoop of an arm and lets her hold him for a minute. They are talking, teasing, but they have slowed down, and now they are walking side by side. Her arm lingers, draped around his neck, and her hand moves in rhythm with her words.

The other woman, the watcher, turns to her husband. He has been beside her all evening, but for the first time since arriving at the park, she sees him clearly, feels his hand holding hers, hears the words he is saying. He is telling her about his childhood, the hot nights when he and his brother would walk across this park to buy Italian ices. The woman searches his face and finds, as she knew she would, a trace of the light-hearted boy who danced along these paths with his twin, so many summers ago.