The center. The edge. Magnetic north. How we move in circles around it. These poles, this equator. Right. Longitude. Left. The Y axis. Vertical alignment. Movement across a plane. Concentric. Parallel. How we understand space, our placement in it, our relation to others. What responsibility we have when static, what inertia we have when moving. How we never stop. How we always stop. How we are stopped. The bend of the back when we stop.