3 ms·
The Lyapunov exponent of such a system is positive -- and probably substantially so, since there are thousands to millions of massive objects being simulated --
by uoaei 4y ago
The Lyapunov exponent of such a system is positive -- and probably substantially so, since there are thousands to millions of massive objects being simulated -- so it seems at first pass as if the absence of any determining factor in the dynamical model will hugely affect the simulation's evolution.
- sebzim4500 4y agoSure, but the goal of these simulations is qualitive results about how galaxies behave, not a quantitative prediction of exactly where every star will be in a billion years. It's like predicting climate vs. weather.
- uoaei 4y agoAny smoothed and incomplete approximation to climate models is also devestating for qualitative similarities of results to data. The point is that the chaos inherent in the dynamics means that n-body solvers that aggregate e.g. spatial regions into low-rank approximations are losing enough detail that it could result in different dynamics being expressed. Like using too large of a mesh size in CFD calculations.