Kiszámíthatatlanság

Kiszámíthatatlanság, or unpredictability, is a concept used to describe the inability to forecast future states of a system with certainty from its current state and known laws. The term is Hungarian, formed from kiszámítható (calculable) and -tlanság (a suffix indicating a property). In scientific use, kiszámíthatatlanság encompasses both practical limits due to imperfect information and, in some contexts, intrinsic randomness of nature.

Two broad notions are commonly distinguished. Epistemic unpredictability arises from incomplete knowledge, insufficient data, or overly complex models, so improved information or methods may enhance predictability. Ontological (or intrinsic) unpredictability refers to genuine randomness in the system, where even perfect knowledge of the current state does not determine a unique future outcome.

Examples illustrating kiszámíthatatlanság include chaotic dynamical systems, such as weather, where small errors in initial conditions grow rapidly, making long-term forecasts unreliable despite deterministic rules. In quantum mechanics, inherent probabilistic outcomes (for example, the result of a single measurement) reflect ontological unpredictability. In everyday contexts, complex processes like financial markets or population dynamics often exhibit practical unpredictability due to high dimensionality and nonlinear interactions.

Quantifying unpredictability involves concepts such as Lyapunov exponents (positive values indicate sensitive dependence on initial conditions), entropy (uncertainty in a system’s state), and algorithmic complexity (the shortest description length of a process). The notion also relates to discussions in philosophy about determinism, free will, and the limits of scientific prediction.

Overall, kiszámíthatatlanság emphasizes the boundary between what can be known or controlled and what remains beyond reliable foresight, shaping approaches across physics, mathematics, and the social sciences.