Weight shift: what dance knows about easing curves
on moving between states
In dance you learn to move your weight before you move your feet. The foot follows; the pelvis leads. The transition is never abrupt — there is always a moment of committed lean, a shift of center, before the body arrives somewhere new.
Easing curves in animation work the same way. The ones that feel right are the ones that commit to a direction before they arrive. The ones that feel wrong are the ones that start and stop at the same speed — no weight, no intention.
I keep thinking about this when I write CSS transitions. The default ease is better than linear, but it still hedges. Something like cubic-bezier(0.25, 0, 0, 1) — a fast start, a slow settle — has the shape of an actual body landing.