Luo Ji is a sociologist and cosmologist who becomes one of the Wallfacers, a group of four individuals tasked with devising secret plans to resist the invasion of the Trisolarans, an alien civilization from a three-sun system. He plays a crucial role in the outcome of the novel and its sequels.

The last painting is Luo Ji, his wife Zhuang Yan and their daughter.

See also:

Ye Wenjie

Two famous scenes in The Three-Body Problem

Travel to Trisolaris