The compelling mathematical challenge of the three-body problem
news.ucsc.edu
news.ucsc.edu
In physics, folks like to refer to simple models which inform other models: the harmonic oscillator, the hydrogen atom, two body scattering and so on. The three body problem is one of the simplest commonly encountered physical problems for which there is no general solution on the torus (Montgomery found a particular solution on the torus). As such, it has driven forward a lot of research and innovation in theoretical physics tools. You could write a pretty good and beefy physics book where you only talk about the three body problem with central potentials.
Not even sure where the PDF is at this point; if I dig it up I'll put it on my blog.
http://scholarpedia.org/article/N-body_choreographies
But basically: some are, some aren't, and we can't generally tell (yet) which is which.
there are also important applications, like figuring out the right orbit and starting points for kerbin bodies in the principia n-body mod