The ‘three-body problem’ refers to the challenge in classical mechanics of predicting the motions of three celestial bodies (such as planets, stars or moons) as they move under the influence of their mutual ‘gravitational attraction’ within physical reality.
The term ‘three-body’ in the name indicates the involvement of three objects, whose future positions and paths are determined by their initial positions, masses, and velocities.
Formulated by Isaac Newton in the 17th century, this problem arises from the complexities of calculating the gravitational interactions between all three bodies (positions, masses, and velocities).
However, the specific challenge of predicting the exact motions of three bodies due to their mutual gravitational influences wasn’t formulated by Newton alone (var. works incl. those by Henri Poincaré, and other researchers over the centuries). Over time, the three-body problem has been vital in the development of modern classical mechanics, chaos theory, and celestial mechanics.
