Any long running calculation where the new state depends on the old state and there isn't much of a correction factor. Anything with "sensitive dependance on in

Any long running calculation where the new state depends on the old state and there isn't much of a correction factor. Anything with "sensitive dependance on initial conditions", any dynamical systems. For example: simulating the three body problem (three celestial bodies of equalish size orbiting eachother). Very small differences get amplified, and any difference at all in how the math is implemented on different systems will result in divergent solutions.