N-body problem

The n-body problem is about how to figure out the movements of a bunch of objects that are all moving around each other and affecting each other with their gravity. Imagine two people holding hands and spinning around. The n-body problem is all about figuring out how they move and where they will end up. Scientists use mathematics to try and solve this complicated problem. It's a difficult problem, but a lot of people have spent a lot of time working on it and have come up with some pretty amazing solutions.