stabilitat

Stabilitat is the property of a system to resist disturbances and to remain in or return to an equilibrium state. The concept is used across sciences and engineering to describe how systems withstand perturbations and preserve function over time. Stability can refer to a rest state, a target value, or a long-run average, depending on the context.

In physics and engineering, stability distinguishes static stability (at rest) from dynamic stability (over time). It is often described using mathematical concepts such as Lyapunov stability and, for specific cases, asymptotic stability, where deviations decay as time progresses. Structural stability concerns whether a structure remains safe under changing loads, while numerical stability relates to algorithms producing bounded errors under computation.

Assessing stability typically involves analytical and numerical methods. Linearization around an equilibrium and examination of eigenvalues, energy or potential functions, and passivity criteria are common approaches. Time-domain simulations and sensitivity analyses also help determine how a system responds to larger perturbations. Stability margins and safety factors are practical measures in engineering design.

Stability appears in many domains. In mechanical and civil engineering, it describes the ability of a bridge or vehicle to maintain controlled behavior under disturbances. In chemistry, stability refers to thermodynamic or kinetic favorability of compounds. In biology and ecology, stability or ecological resilience describes the persistence of populations and ecosystems under stress. In economics and politics, stability concerns low volatility, predictable policy, and continuity of governance.

Stability is related to, but distinct from, resilience and robustness. Stability emphasizes maintaining or returning to a state after perturbation; resilience emphasizes recovery from larger or more frequent disturbances.