Room 8 of 11 · Upper floor
The Bounce
“Can a wall guide without being the boss?”
Lamp waiting
▶ Hear the storyteller tell this roomLook
A small ball rests in a room with angled walls.
Try
Aim and launch the ball. Watch what the walls do.
Notice
Try the experiment first. Then this will fill in.
What keeps this room working?
The walls give a real constraint. Between them, the ball keeps its own path.
What would break this room?
If the wall secretly steered every movement. Or if the wall gave no constraint at all.
Child-sized version
“A boundary can guide without being the boss of everything.”
Try to break the room
For grown-upsShow me the math
A boundary condition is a rule that applies only at the edge of a region. It narrows what can happen there without choosing what happens everywhere.
- Boundary condition
- A rule that acts at the edge and nowhere else.
- Reflection
- The angle in equals the angle out.
- Constraint versus control
- A constraint limits possibilities. It does not pick one.