Definition of Hyperbole
In Chapter 1, Liu describes in detail the shooting of a young girl serving in the Red Guard—only 15 at the time of her death. The Red Union soldiers shoot her without a second thought. Liu uses hyperbole to characterize this tragic event:
Her fifteen-year-old body was so soft that the bullet hardly slowed down as it passed through it and whistled in the air behind her. The young Red Guard tumbled down along with her flag [...].
A bullet would be unlikely to "hardly slow down" after penetrating a human body: on impact, the bullet may pass through her body, but its momentum would be reduced significantly by the collision. Liu uses this instance of hyperbole to emphasize the Red Guard's youth and vulnerability. Her body is young and untested, yet to be hardened by years of experience and armed conflict. She is innocent, despite her warlike cries: the Red Guard's idealism has led her to join this movement, fresh-faced and ready to fight but also perhaps naive about the consequences she'll face for doing so. In the moment of her shooting, her youthful ignorance grinds to a halt as she is forced to contend, all too soon and too quickly, with the deadly forces she has brought down upon herself.
In Chapter 4, General Chang discusses the Frontiers of Science with Wang Miao, making clear what issues are at stake for humankind. Wang has yet to fully comprehend the facts or connect these revelations to an imminent threat. To emphasize the severity of the situation, Chang employs both foreshadowing and hyperbole in the following conversation with Wang:
“Yes, the entire history of humankind has been fortunate. From the Stone Age till now, no real crisis has occurred. We’ve been very lucky. But if it’s all luck, then it has to end one day. Let me tell you: It’s ended. Prepare for the worst.” Wang wanted to ask more, but Chang shook his head and said good-bye, preventing any more questions.
Chang explains to Wang that some new horror is coming, something unlike any disaster humanity has ever experienced. This is both prescient and an instance of overexaggeration, given that the definition of a "real crisis" is relative. The impending Trisolarian invasion may be a crisis, but to someone without food, water, or shelter, extraterrestrial threats must sit far down on the priority list. Any statement of objective "fact" in such a hyperbolic manner should be questioned, especially in a novel so intent on deconstructing objectivity.