A multitude of CPUs, a flood of madness (Simile and Metaphor)
On page 11, narration describes the fervor of the Cultural Revolution in 1967:
"Battles like this one raged across Beijing like a multitude of CPUs working in parallel, their combined output, the Cultural Revolution. A flood of madness drowned the city and seeped into every nook and cranny."
In the first sentence, a simile ("like a multitude of CPUs") compares battles in the Cultural Revolution to computers, communicating that each is a discrete element working with the same programming to produce a large-scale result. Liu uses technical vocabulary to describe historical events, evoking the upcoming science-fiction elements of the novel. One could possibly read more into the simile and make the claim that it removes agency and humanity from battlers themselves, placing "blame" on the programming they've been given (i.e., Maoist thought reform).
In the second sentence, a metaphor ("a flood of madness drowned the city") expresses the inescapable fervor of the revolution. "Madness" exists in human minds, not in objects (or computers, for that matter), but here the madness is outside of minds, covering the literal nooks and crannies of Beijing, leaving nowhere to hide.
Looking at this simile and metaphor together tells us a few things: first, Liu Cixin's writing style features a lot of figurative language; second, Liu's figurative language draws from both technical and natural imagery, often in juxtaposition; and third, it's possible to read a lot into these comparisons, though it might not always be fruitful.
The universe is a cramped heart (Metaphor)
When Wang sees the microwave background radiation flicker at the planetarium, he feels the universe "shrink": "The universe was a cramped heart," and the red light of the cosmic microwave background is the blood. This metaphor compares the entire universe to an organ—and a cramped one at that, evoking a health risk as well as a tight, uncomfortable space. The metaphor also works as a tool to make lofty concepts more relatable: While we might not be able to fully imagine radiation on a universal level, we can certainly imagine the claustrophobic, painful feeling of a cramped human heart.
This is one of many metaphors and similes in Chapter 9 related to changing size as Wang Miao struggles with the reality of the countdown. The figurative language escalates to four size changes in one paragraph on the final page: "Wang Miao once again felt that the universe had shrunk until it was the size of an empty church...he was an ant crawling through the cracks...he felt a giant, invisible hand caressing his trembling heart...he was once again a helpless babe." As Wang Miao panics, his sense of his identity relative to the world destabilizes, expanding and contracting quickly, and this is communicated using rhetorical devices. This linguistic tool is flipped at the very end of the chapter, when Shi interrupts Wang's breakdown—as soon as Da Shi enters, the language becomes plain and factual: "He turned around. Captain Shi Qiang stood there, blowing out a mouthful of white smoke." Liu Cixin juxtaposes device-heavy prose and simplistic prose to create a sense of disruption in the scene and illustrate the differences in these characters' mindsets.
Gaseous layer like a giant mitt (Simile)
In the game Three Body, the secretary general of Trisolaran civilization explains the expansion of the gaseous outer layer of the suns: the gaseous layer's changing size "greatly increases the diameter of the sun, like a giant mitt that can catch planets more easily." This simile, like many of Liu's rhetorical devices, connects a strange concept to a familiar image: a baseball mitt. Mitts protect catchers' hands, as well as increasing their reach—the gaseous layer similarly extends a sun's destructive reach, though in the case of the suns, the baseball (Trisolaris) is destroyed when it is caught. This expanding and contracting mitt of gas, the secretary general explains, effectively guarantees the complete destruction of the Trisolaran solar system.
Antenna like a giant sunflower (simile)
When Ye Wenjie sends her first transmission using the sun as a superantenna, she has to manually track the setting sun. She observes that "the Red Coast antenna seemed like a giant sunflower at that moment, slowly turning to follow the descending sun." This simile compares the antenna to a flower, creating a peaceful image. By extension, the simile compares the antenna's behavior—which Ye is creating manually—to the natural behavior of a plant as it follows light to survive. In this way, Ye's use of the antenna is made to feel natural and inevitable.
Ship like a deck of cards (Simile)
When Judgment Day is cut open by nanofilaments, it separates into more than forty thin horizontal slices and crashes into the side of the canal. The upper slices move faster than the lower ones, and as a result, Liu writes, the "ship spread open like a deck of cards." This simile again connects a strange image to a well-known one, and it's a bit playful—like the ship's destruction is the beginning of a large-scale magic trick, and someone is about to be asked to pick a card. By the end of its destruction, Judgment Day is "spilled on the shore like a stack of plates carried by a stumbling waiter," and the slices look "as soft as cloth." While rhetorical devices are excellent tools to describe strange events, using so many in close proximity creates a hodgepodge of impressions—from cards to plates to cloth in four sentences—that might in fact muddle the image rather than illustrating it, creating a sense of indescribable surrealism rather than a clear, cohesive concept.