After almost 350 years, physicists have just arrived at a statistical solution for Newton's three-body problem – that is, the problem of figuring out how three similar objects or bodies are going to travel in space in a way that fits in with the laws of motion and gravity. //

The researchers behind the latest study describe the three-body problem as "arguably the oldest open question in astrophysics", and while they haven't completely cracked the case, they've gotten closer than most by finding a statistical formula that fits this open question in certain scenarios.
In particular, they looked at a couple of centuries of previous research that puts forward the following idea: in unstable, chaotic three-body systems, one of those bodies eventually gets expelled, leaving behind a stable binary relationship between the two that are left. //

The three laws of motion laid down by Isaac Newton in 1687 are these: that objects remain in a state of inertia unless acted upon by force, that the relationship between acceleration and applied force is force equals mass times acceleration (F=ma), and that for every action there is an equal and opposite reaction.

So far so brilliant, as far as the basic physics of the Universe are concerned. But Newton ran into difficulties applying his rules to the Earth, Moon and Sun – the original three bodies. It actually became much harder to track three bodies with these mathematical rules.
While scientists have found fixes for special cases, a general formula for the three-body problem has proved elusive. It's like trying to apply a mathematical template to the butterfly effect – it's just too chaotic to track.