Astrophysics problems

What is theoretical astrophysics?

The principal task of theoretical astrophysics is the interpretation of results of observations with the purpose of studying the structure of the objects encountered in the Universe, and to study the physical processes taking place in it

2008 science fiction novel by Liu Cixin

The Three-Body Problem is a novel by the Chinese science fiction author Liu Cixin

The first within the Remembrance of Earth's Past trilogy—though the series as a whole is often referred to as The Three-Body Problem

Or simply as Three-Body.The series portrays a fictional past

Present and future wherein Earth encounters an alien civilization from a nearby system of three sun-like stars orbiting one another

In an example of the three-body problem in orbital mechanics.