Already, there are hints of what institutions and the spaces they occupy could look like. If even some come to pass, they could alter Americans’ relationship with the public realm.

— Vibrating pagers like those used at chains like Red Lobster. Already some hospitals are handing them out; instead of entering a lobby, wait in the car until you buzz.

— Arrows on the ground, and other physical markers to encourage and enforce distance. Imagine sidewalks with scoring every 6 feet (2 meters) so those walking could make sure they’re the human equivalent of a few car lengths behind. Or large sculptures deployed to separate people.

— New designs for eating places. McDonald’s is already prototyping a socially distanced version of its restaurant that could be a template for fast-food spaces around the world.

— Checkerboard grids on the grass in parks, with people allowed to occupy one square only if those surrounding it are empty. Or time-sharing of public places: If you don’t show up for your 12:15 p.m. slot at the playground, you’re out of luck.