Chaotic Era is a term used in the 'Remembrance of Earth's Past' series. During an Chaotic Era, the the sun in the trisolarian world follow no pattern, and it is almost impossible to survive. Civilization can only develop in the mild climate of Stable Eras. Most of the time, the trisolarians must collectively dehydrate and be stored. When a long Stable Era arrives, they collectively revive through rehydration. Then they proceed to build and produce. Because of the three body problem, the arrival and duration of the Chaotic Era could n/ever be predicted, therefore the trisolarians decided to occupy earth.

A [concept] scene of the Chaotic Era in the Fiery Flames (but more so looking like the great rip) of the Three Body (game).
Description[]
[According to the Count of the West:] Other than Stable Eras, all times are Chaotic Eras. The sun doesn't always rise in the morning. That's what a Chaotic Era is like. The Chaotic Era is also marked by extreme changes in temperature. One moment it can be boiling hot, the other moment icily cold. After a long, frigid night lasting several days' worth of time, a brief but scorching day might follow, and vice versa. The sun follows no pattern.
As they spoke, Wang noticed the sky brightening over another part of the horizon. He couldn't be sure of the compass directions, but he was sure the direction this time was different from last time. The sky grew brighter, and soon, the sun of this world rose. It was small and bluish in color, like a very bright moon. Wang still felt a bit of warmth, and could now see the landscape around him more clearly. But the day didn't last long. The sun traversed a shallow arc over the horizon and soon set. Night and the bone-chilling cold once more settled over everything.[1]
Soon after this, however, dawn did appear over the horizon. The sky brightened rapidly, and the sun rose. Wang noticed that this time, the sun was gigantic. After just half of it rose, it took up at least one-fifth of the visible horizon. Waves of heat bathed them, and Wang felt refreshed. But when he glanced over at King Wen and Follower, he saw that both had terror on their faces as though they had seen a demon.
"Quick! Find shade!" Follower shouted. Wang ran after them. They ducked behind a large rock. The shadow cast by the rock gradually grew shorter and shorter. The earth around them glowed as though on fire. The permafrost beneath them soon melted, the steel-like hard surface turning into a sea of mud, roiled by waves of heat. Wang sweated profusely.
When the sun was directly overhead, the three covered their heads with the animal hides, but the bright light still shot through the holes and gaps like arrows. The three shifted around the rock until they were able to hide inside the new shadow that had just appeared on the other side.
After the sun set, the air remained hot and damp. The three sweat-drenched travelers sat on the rock. Follower spoke with dismay. "Traveling during a Chaotic Era is like walking through hell."[1]
Unpredictability[]
Every kind of timepiece indicated that the time for sunrise had passed, but the horizon remained dark in every direction. Ten hours later, there was still no sign of the sun, not even the slightest hint of dawn. The endless night lasted through a whole day, then two days. Coldness now pressed toward the earth like a giant hand.
Inside the pyramid, King Wen knelt before King Zhou, pleading, "My king, please continue to have faith in me. This is but temporary. I have seen the yang of the universe gathering, and the sun will rise soon. The Stable Era and spring will continue!"
"Let's begin to heat the cauldron," King Zhou said, and sighed.
A minister stumbled through the cavelike entrance into the Great Hall. "There … there are three flying stars in the sky!"
Those in the Great Hall were stunned. The air seemed frozen. Only King Zhou remained impassive. He turned to Wang, to whom he had never deigned to speak before. "You still don't understand what the appearance of three flying stars means, do you? Ji Chang, why don't you tell him?"
"It indicates the arrival of a long period of extreme cold, cold enough to turn stone into dust." King Wen sighed.
"De-hy-drate…" King Zhou again chanted in that strange, otherworldly voice. Outside, people had already begun the process. They turned themselves back into dehydrated bodies to survive the long night that was coming. The lucky ones had time to be stacked in the dehydratories, but many were abandoned in the empty fields.
King Wen stood up slowly and walked toward the cauldron over the roaring fire in the corner of the Great Hall. He climbed up the side and paused for a few seconds before jumping in. Perhaps he had seen the thoroughly cooked face of Fu Xi laughing at him from the soup.[1]
Cold era[]
"Keep the fire low," King Zhou ordered, his voice weak. Then he turned to the others. "You may exit if you wish. The game is no longer fun after it gets to this point."
A red EXIT sign showed up above the Great Hall's cavelike entrance. Players in the Great Hall streamed toward it, and Wang followed the crowd. Through the long tunnel, they finally emerged outside the pyramid. Heavy snow falling through the night air greeted them. The bone-chilling cold caused Wang to shiver, and a display in a corner of the sky indicated that game time had sped up again.
The snow continued without pause for ten days. By now the snowflakes were large and heavy, like pieces of solidified darkness. Someone whispered next to Wang, "The snow is now composed of frozen carbon dioxide, dry ice." Wang turned around and saw that the speaker was Follower.
After another ten days, the snowflakes turned thin and translucent. By the weak light from a few torches within the entrance to the long tunnel, the snowflakes gave off a faint blue glow, like pieces of dancing mica.
"Those snowflakes are now composed of solidified oxygen and nitrogen. The atmosphere is disappearing through deposition, which means it's near absolute zero above."
Snow gradually buried the pyramid. The lowest layers were composed of water snow, then dry ice, and finally, on top, snow made of oxygen and nitrogen. The night sky became especially clear, and the stars glowed like a field of silver bonfires. A line of text appeared against the starry background:
- The long night lasted forty-eight years. Civilization Number 137 was destroyed by the extreme cold. This civilization had advanced to the Warring States Period before succumbing.
- The seed of civilization remains. It will germinate and again progress through the unpredictable world of Three Body. We invite you to log on in the future.
Before exiting the game, Wang noticed the three flying stars in the sky. Revolving closely around each other, they seemed to perform a strange dance against the abyss of space.[1]