# Springs & Constraints

**Track:** Physics, Motion & Emergence — Creative Coding — the existing 50
**Framework / surface:** p5.js
**Level:** Intermediate
**Prerequisites:** Forces & Acceleration, Oscillation

**In one line:** A force that pulls toward a rest length — bouncy, elastic motion.

## Theory, aesthetics & inspiration

A spring is a force with a memory of rest: stretched or compressed, it pulls back toward a preferred length in proportion to how far it has been displaced. Robert Hooke captured this in the 1670s as "ut tensio, sic vis"—as the extension, so the force. Coupled to mass and damping, the rule yields oscillation that decays, the bounce and settle of elastic things. Networks of springs become cloth, hair, soft bodies, and jelly-like constraint systems. The aesthetic is responsiveness: matter that wobbles, recoils, and overshoots before coming to rest, lending digital objects a tactile, almost muscular compliance that rigid translation never achieves.