The kind of invisible I am thinking of involves inanimate objects.
Later, when I was in charge of bulletin boards at Knowlton Elementary, I used the same theory to create animated bulletin boards in the school lobby. I used unfolded paper clips, embedded in the composition board ceilings to thread fishing line attached to the school doors. In the winter months I had little bent-kneed skiers connected to the line. They went up and down cotton-topped mountains constructed in 3D. The fun thing about using invisible wire in a school is there were multiple doors and could therefore be multiple lines going to multiple skiers. Kids could stand at the bulletin boards and watch the flow and motion as other kids opened doors. In the spring I created colorful pots, from which little flowers would rise when the doors were opened. And Kites that would fly up and down in the breeze of doors opening and closing. I tell ya, I had an awful lot more fun and fulfillment in that PTA job than when I was president. Serious fulfillment! I had to make sure I was there when school started, or when it let out. That’s where the joy was found! I would sort of have to make myself invisible, looking from the corner of my eyes at those delighted seven year-olds, trying to figure out how those flowers popped up and down.
Joy, joy joy!
I think I need to volunteer at the elementary school again. I’m getting stale.