A plot of the Lorenz attractor for values r = 28, σ = 10, b = 8/3An animation of a double-rod pendulum at an intermediate energy showing chaotic behavior. Starting the pendulum from a slightly different initial condition would result in a vastly different trajectory. The double-rod pendulum is one of the simplest dynamical systems with chaotic solutions.
Small differences in initial conditions, such as those due to errors in measurements or due to rounding errors in numerical computation, can yield widely diverging outcomes for such dynamical systems, rendering long-term prediction of their behavior impossible in general.[8] This can happen even though these systems are deterministic, meaning that their future behavior follows a unique evolution[9] and is fully determined by their initial conditions, with no random elements involved.[10] In other words, the deterministic nature of these systems does not make them predictable.[11][12] This behavior is known as deterministic chaos, or simply chaos. The theory was summarized by Edward Lorenz as:[13]
Chaos: When the present determines the future but the approximate present does not approximately determine the future.
^ abcBishop, Robert (2017), "Chaos", in Zalta, Edward N. (ed.), The Stanford Encyclopedia of Philosophy (Spring 2017 ed.), Metaphysics Research Lab, Stanford University, retrieved 2019-11-24
^Werndl, Charlotte (2009). "What are the New Implications of Chaos for Unpredictability?". The British Journal for the Philosophy of Science. 60 (1): 195–220. arXiv:1310.1576. doi:10.1093/bjps/axn053. S2CID354849.