Remembrance of Earth's Past feats, power & lore discussion thread

[Stocking Anarchy]

After the Doomsday Battle, the droplet approaches the Earth at speeds of 75 kilometers per second.

On the car’s television, they saw that the droplet was approaching Earth at a speed of seventy-five kilometers per second and showed no sign of slowing. At that rate, it would arrive in three hours.

The droplet sends a powerful electromagnetic wave directly at the Sun with an intensity that far exceeds the Suns amplification threshold, and thus, humanity is prevented from using the Sun as a method to transmit messages to the Universe.

The droplet was sending a continuous, powerful electromagnetic wave directly at the sun with an intensity far exceeding the sun’s amplification threshold and a frequency that covered all the bands that the sun could amplify.
Luo Ji began to giggle, and then laughed until he choked. Yes, he really was self-absorbed. He should have thought of all of this long ago. Luo Ji wasn’t important. The sun was important. From now on, humanity could no longer use the sun as a powerful antenna to transmit messages to the universe.

(From The Dark Forest)

 

[Stocking Anarchy]

After the droplets destroy all the gravitational wave antennae (and with them the Dark Forest Deterance System), another fleet is sent from Trisolaris, this one of 415 ships. However, due to the technological and scientific advances of the Trisolarans in that time, their ships are now capable of reaching lightspeed.

Three days after the Second Trisolaran Fleet left the interstellar cloud, the observation system detected 415 trails in the second interstellar cloud. These trails couldn’t belong to a different fleet. The First Trisolaran Fleet had taken five years to go from the first dust cloud to the second, while the Second Trisolaran Fleet had taken only six days.
The Trisolarans had achieved lightspeed.
Analysis of the trails in the second interstellar dust cloud confirmed that they continued to extend through the cloud at lightspeed. At such high velocities, the trails left by the ships’ impacts became particularly prominent.

The second Trisolaran fleet only enters lightspeed after leaving the Trisolaran system and before entering the Solar System, and the reason concluded for this is so as not to harm either star system. This would also mean that the power generated by the lightspeed drives are a staggering two orders of magnitude greater than a star.

This was a bit puzzling. It appeared as if the Trisolar ships were capable of entering and dropping out of lightspeed within an extremely short period of time, but they chose not to do so too close to the Trisolaran star system or the Solar System. After the fleet had left Trisolaris, the ships accelerated under conventional power for an entire year, until they were about six thousand AU from home, before entering lightspeed. Similarly, they dropped out of lightspeed at the same distance from the Solar System and switched to conventional deceleration. This distance could be covered in a month at lightspeed, but the fleet chose to spend a year traversing it. The cruise of the Second Trisolaran Fleet would thus take two years longer than it would if the entire voyage were conducted at lightspeed.
Only one explanation for this curious decision came to mind: It was motivated by a desire not to harm either solar system during the process of entering and dropping out of lightspeed. The safe radius appeared to be two hundred times the distance from the Sun to Neptune. This suggested that the power generated by the drives was two orders of magnitude greater than a star, which seemed unimaginable.

(From Death's End)

 

[Stocking Anarchy]

At the end of the Deterrence Era, humanities fleet has only just over 100 stellar-class warships, and it takes a year of acceleration to reach their full speed of 15% the speed of light. To the contrary, the ships of the Trisolarans second fleet can leap into lightspeed without a prolonged process of acceleration.

After the Doomsday Battle, the Solar System Fleet had never returned to its former size. Even at the end of the Deterrence Era, the fleet had barely more than one hundred stellar-class warships. Though technology had continued to improve, the maximum speed of the ships never increased, as fusion propulsion had already been pushed to the limit. The overwhelming advantage the Trisolar ships held was not only their ability to reach lightspeed, but, more terrifyingly, their ability to leap into lightspeed without a prolonged process of acceleration. In order to reach even 15 percent of lightspeed, human ships had to accelerate for a year, taking into account fuel consumption rates and the need to reserve fuel for the return voyage. Compared to Trisolaran ships, Earth ships were slow as snails

 

[Stocking Anarchy]

After the Gravity and the Blue Space expose the location of Trisolaris and the Solar System to the Dark Forest, a hunter retaliates, and Trisolaris is destroyed, causing a blinding light visible on Earth over 4 lightyears away that lasts for around half an hour.

One night, the telephone roused Cheng Xin from her slumber. She saw that the caller was Fraisse. It was 1:14 A.M. in China, and 3:14 in Australia. Fraisse knew that Cheng Xin suffered from severe insomnia, and without a sleep-aid machine, she could only manage two to three hours of rest a night. Unless it was an emergency, he would never be disturbing her at a time like this.
He sounded anxious. “Child, go out and look up in the sky.”
Cheng Xin could already tell something unusual was happening. In her uneasy sleep, she had been gripped by a nightmare. The dream was a familiar one: A gigantic tomb stood in the middle of a plain covered by the darkness of night. A bluish glow spilled from within the tomb and illuminated the ground nearby....
Just that kind of blue light could be seen outside.
She went onto the balcony and saw a blue star in the sky, brighter than all the other stars. Its fixed position distinguished it from the man-made structures orbiting in near-Earth orbit. It was a star outside the Solar System. Its brightness was still intensifying, and even overpowered the lights of the city around her, casting shadows against the ground. About two minutes later, the brightness reached a peak and was brighter even than a full moon. It was no longer possible to look at it directly, and the color of the light shifted to a harsh white, illuminating the city as though it were daytime.
Cheng Xin recognized the star. For almost three centuries, humans had looked at it more than at any other spot in the heavens.
Someone screamed in the leaf-building nearby, and there was the sound of something crashing to the floor.
The star now began to fade. From white it gradually dimmed to red, and about half an hour later, it went out.
Cheng Xin hadn’t brought the phone with her, but the floating communication window had followed her. She could still hear Fraisse’s voice, which had recovered its usual serenity and transcendence. “Child, don’t be afraid. What will happen, will happen.”
A lovely dream had ended: Dark forest theory had received its final confirmation with the annihilation of Trisolaris.

The process of the annihilation of Trisolaris; the photoid strikes the star that Trisolaris is currently orbiting, creating a hole 50,000km across and ejecting a part of the stars core into space, which reaches the orbit of Trisolaris in 4 hours (over a distance of 0.6 AU).

At the time of the catastrophe, Trisolaris was in a stable era, orbiting around one of the three stars in the system at a distance of about 0.6 AU. The photoid struck the star and tore a hole through the photosphere and the convection zone. The hole was about fifty thousand kilometers in diameter, wide enough for four Earths laid side by side. Whether as a result of a deliberate choice by the attacker or coincidence, the photoid struck the star at a point along the line where the star intersected Trisolaris’s ecliptic plane. Viewed from the surface of Trisolaris, an extremely bright spot appeared on the surface of the sun. Like a furnace with its door open, the powerful radiation generated by the core of the sun shot through the hole; passed through the convection zone, the photosphere, and the chromosphere; and struck the planet directly. All life outdoors on the hemisphere exposed to the radiation was burnt to a crisp within a few seconds.
Next, material from the core of the sun erupted from the hole, forming a fifty-thousand-kilometer-thick fiery plume. The spewed material was tens of millions of degrees in temperature, and while some of the material fell back onto the surface of the sun under the influence of gravity, the
remainder reached escape velocity and shot into space. Viewed from Trisolaris, a brilliant tree of fire grew from the surface of the sun. About four hours later, the ejected solar material reached 0.6 AU from the surface of the sun, and the tip of the flaming tree intersected the orbit of Trisolaris. After another two hours, the orbiting planet reached the tip of the fire tree and continued to pass through the ejected solar material for about thirty minutes. During this time, the planet might as well be moving through the interior of the sun—even after the journey through space, the spewed material was still at a blazing temperature of tens of thousands of degrees. By the time Trisolaris emerged from the fire tree, it glowed with a dim red light. The entire surface had liquefied, and an ocean of lava covered the planet. Behind the planet was a long white trail through space—steam from the boiled-off ocean. The solar wind stretched the trail out, making the planet appear as a long-tailed comet.
All signs of life on Trisolaris had been cleansed away, but only the fuse of the catastrophe had been lit.

Trisolaris falls into the sun, and shortly after that, due to there being less mass and slower fusion in the stars core, the star collapses and explodes.

The ejected solar material caused drag against the planet. After passing through the material, Trisolaris slowed down, and its orbit fell lower toward the star. The fire tree acted like a claw extended from the sun, pulling Trisolaris down with each revolution. After about ten more revolutions, Trisolaris would fall into the sun itself, and the cosmic football game played between three suns would come to its end. But this sun wouldn’t survive long enough to see itself emerge as the victor.
The solar eruption also lowered the pressure inside the sun, temporarily slowing down the fusion within the core. The sun dimmed rapidly until it was but a hazy outline. The giant fiery tree growing from the surface, in contrast, appeared even more striking, more brilliant, like a sharp scratch made against the inky black film of the universe. The diminished fusion meant that the core radiation no longer exerted sufficient pressure against the weight of the solar shell, and the sun began to collapse. The dim shell fell into the core, triggering a final explosion.
This was the sight witnessed by humankind three days ago on Earth.

The ensuring supernova wipes out everything in the planetary system, the vast majority of spaceships and space habitats were vaporized as they tried to escape. Only a small number of lucky survivors managed to escape as they were behind the other two suns when the star exploded.

The solar explosion destroyed everything within the planetary system: The vast majority of spaceships and space habitats trying to escape were vaporized. Only a few extremely fortunate ships that happened to be behind the two other suns, which acted as shields, were safe.

Including the two fleets, only a thousanth of all the people of Trisolaris survived.

“How many escaped?” Cheng Xin asked softly.
“Counting the Trisolaran Fleets far from home, no more than one-thousandth of the entire population.” Sophon’s reply was even softer than Cheng Xin’s query. She was focused on the Way of Tea, and did not raise her head.

(All of the above is from Death's End)

 

[Stocking Anarchy]

The star of the Trisolaran System that was destroyed was very similar to the Sun in terms of mass and position in the main sequence, allowing humanity to calculate the possibilities of a photoid striking the Sun and the energy it would produce and its effects on the planets of the Solar System.

Since the star that was destroyed was very similar to the Sun in terms of mass and position in the main sequence, humanity could potentially create a precise mathematical model of the catastrophic failure of the Sun in the event of a dark forest strike. As a matter of fact, this research had begun in earnest as soon as those on Earth had witnessed the end of Trisolaris.

 

[Stocking Anarchy]

Droplets have a mass of less than 10 tons (or over 9 tons).

“What is its mass?” Ding Yi asked.
“We don’t have an exact value right now. A rough value, obtained through high-precision gravitational instruments, is less than ten tons.”

There were various hypotheses about the manner in which the droplet might self-destruct, but the maximum release of energy would come from self-destruction by antimatter annihilation. Since the droplet had a mass of less than ten tons, the largest energy burst that needed to be considered was that produced by the annihilation of five tons each of matter and antimatter.

(From The Dark Forest)

 

[Stocking Anarchy]

As the different stellar-class warships of the combined fleet are destroyed by the droplet in the Doomsday Battle, they are repeatedly referred to as weighing a million tons each.

The fusion fireball on Infinite Frontier had gone out, leaving the ship’s hull totally melted. Now it exploded, spewing a million tons of glowing, dark-red metallic liquid like a bud bursting into bloom, the molten metal scattering unimpeded in an omnidirectional storm of burning metallic magma.

Most of the fragments scattered through space in storms of exploded debris were liquid metal melted by the high-temperature nuclear blasts, upward of a million tons melted in the destruction of each ship.

The droplet surged like lightning, and in the space of just ten seconds, it passed through twelve warships: Ganges, Columbia, Justice, Masada, Proton, Yandi, Atlantic, Sirius, Thanksgiving, Advance, Han, and Tempest. As in the destruction of the first row, each warship turned red-hot after penetration, before being engulfed in a nuclear fireball that left a million tons of dark red, glowing, metallic magma that then exploded. In this brutal destruction, the lined-up warships were like a two-thousand- kilometer fuse that burned with such intensity that it left behind nothing but ash glowing a dull, dark red.

 

[Stocking Anarchy]

The Gravity is 1500m (1.5km) long.

Now, Hunter’s mission was almost over. The degenerate matter vibrating string at the heart of the gravitational wave antenna, less than ten nanometers in diameter but running the entire length of the fifteen-hundred-meter hull, had almost reached its half-life.

Further reference to the Gravity being over 1km long.

The doctor pulled Guan Yifan along, and the two drifted toward the bow of the ship. If the ship were accelerating, going from the stern of the ship to the bow would be equivalent to climbing up a one-kilometer well, but in the weightlessness of coasting, the trip was a lot easier.

 

[Stocking Anarchy]

Trisolaris resides in the Alpha Centauri system, just over 4.3 lightyears away from Earth.

As she read the flashing green text on the display, Ye was no longer capable of thinking clearly. Her mind, inhibited by shock and excitement, could only understand this: No more than nine years had passed since the time she had sent the message to the sun. Then the source of this transmission must be around four light-years away. It could only have come from the closest extra-solar stellar system: Alpha Centauri.*34

*34 Translator’s Note: Alpha Centauri, though appearing to the naked eye as a single star, is actually a double-star system (Alpha Centauri A and Alpha Centauri B). A third star, called Proxima Centauri and invisible to the naked eye, is probably gravitationally associated with the double-star system. The Chinese name for the objects ( ) makes it clear that the “star” is really a system of three stars.

Gradually, as fantasies about that distant civilization grew more and more elaborate, the Redemptionists developed spiritual feelings toward Trisolaran civilization. Alpha Centauri became Mount Olympus in space, the dwelling place of the gods; and so the Trisolaran religion—which really had nothing to do with religion on Trisolaris— was born.

(From The Three-Body Problem)

 

[Stocking Anarchy]

In the Broadcast Era, stellar hydrogen bombs have a yield of around 300 megatons.

The power of nuclear bombs was no longer measured in TNT-equivalents, but this bomb’s yield would be approximately three hundred megatons.

(From Death's End)

 

[Stocking Anarchy]

In the Bunker Era, most of humanity live in bunker cities hiding behind the four gas giants (incase of a photoid strike on the Sun). One of these cities, Space City Asia I, is a cylinder 30km long and has a diameter of 7km, with an interior surface area of 659km^2.
Asia I used to have a population of over 20 million, but currently has a population of 9 million.

Space City Asia I was one of the earliest to be built as part of the Bunker Project. It was a regular cylinder that simulated gravity with the centrifugal force generated by spinning. With a length of thirty kilometers and a diameter of seven kilometers, its usable interior surface area was 659 square kilometers, about half the size of ancient Beijing. Once, about twenty million inhabitants had lived here, but after the completion of newer cities, the population had decreased to about nine million, so that it was no longer so crowded....

North America I is another Space City in the shape of a sphere with a single miniature sun in the middle, and gravity the strongest in the middle and weaker at the edged.

The first was North America I, the closest city to Asia I. The main advantage of its spherical construction was that a single artificial sun at the center was sufficient to illuminate the entire city, but the disadvantage of such a design was obvious as well: The gravity changed depending on one’s latitude. The equator had the most gravity, which decreased as you went up in latitude. The polar regions were weightless. Inhabitants in the different regions had to adjust to life under various gravity conditions.

Buildings near the edge of North America I can be built as tall as 10km tall due to the low-gravity.

Cheng Xin saw that the buildings here were denser and taller, looking like a metropolis. At the high-latitude, low-gravity regions especially, the buildings’ heights were limited only by the volume of the sphere. Near the polar regions, some buildings were as tall as ten kilometers, looking like long thorns extending up from the ground toward the sun.

North America I has a radius of 20km (and thus a diameter of 40km) and a population of 20 million, making it the most populated of the space cities.

North America I had been completed early on. With a radius of twenty kilometers and twenty million inhabitants, it was the largest city by population. It acted as the prosperous commercial center for all the Jovian cities.

Most space cities of the Bunker Worlds have an equitorial ocean (with water from Europa), and circumnavigating these seas on boats is possible. Sometimes when the city has to engage in unexpected maneuvers, small scale flooding will occur.

Here, Cheng Xin got to see a splendid sight that was absent from Asia I: the equatorial ring-ocean. As a matter of fact, most space cities had ring- oceans of various widths, and Asia I was rather unique in lacking one. In spherical or football-shaped cities, the equator was the lowest point in the city’s simulated gravity, and all the city’s water naturally collected there, forming a sparkling, undulating belt for the city. Standing on the shore, one could see the ocean rising on both sides and dividing the “sky” behind the sun. Cheng Xin and Cao Bin took a fast boat and navigated around the sea —a journey of some sixty kilometers. The water in the sea came from Europa, clear, cold, and reflecting rippling light onto the skyscrapers on both sides. The dikes along the edge of the sea closest to Jupiter were higher, to avoid the water spilling out when the city accelerated during position adjustments. Even so, when the city had to engage in unexpected maneuvers, small-scale flooding would occur from time to time.

Europe IV is football-shaped and is 40km long. It has multiple artificial suns, one for each segment, and it's axis is one long building.

Next, Cao Bin took Cheng Xin to Europe IV, which sported a typical football-shaped design. Its distinguishing characteristic was the lack of a common artificial sun. Every district had its own miniature fusion sun, and the tiny suns hovered about two hundred to three hundred meters high to provide illumination. The advantage of this approach was that the weightless axis could be more efficiently utilized. The axis of Europe IV was taken up by the longest—or tallest—building among all the space cities. It was forty kilometers long and connected the north and south poles of the football. Since the interior of the building was weightless, it was mainly used as a spaceport and commercial entertainment district.

Europe IV has the smallest population of all the space cities (or at least all the large space cities) with a population of 4.5 million, and it is the wealthiest of space cities, with there being yachts in it's equitorial sea.

Europe IV had the smallest population of all the cities, only 4.5 million. It was the wealthiest city of the Bunker World. The exquisite houses illuminated by miniature suns amazed Cheng Xin. Each house came with its own swimming pool, and a few had wide lawns. Tiny white sails dotted the serene equatorial sea, and people sat on the shore, fishing leisurely. She saw a yacht sail by slowly, and it looked as luxurious as any yacht on ancient Earth. There was a cocktail party being held aboard the yacht with live musicians.... She was astonished that such life could be transplanted into the shadow of Jupiter, eight hundred million kilometers from the Earth.

Some space cities are built not fur human habitation, but rather for industry and agriculture. Resource I, for example is 120km long and 3km wide, and rather than rotating on it's axis it tumbles around its centre. Multiple space cities like this can be combined into crosses or stars.

There were some other cities with even stranger designs. Most of these were industrial or agricultural centers with no permanent residents. For instance, there was a city called Resource I. Its length was 120 kilometers, but the diameter was only three kilometers, like a thin stick. It did not spin around the long axis, but rather, tumbled about its center, end over end. The city’s interior was divided into levels, and the gravity at each level differed dramatically. Only a few levels were suitable for living, while the rest were devoted to various industries adapted to the different gravities. According to Cao Bin, near Saturn and Uranus, there were cities formed by combining two or more stick-shaped cities into crosses or stars.

The biggest combined city is in Neptunes shadow, and combines four space cities for a total length of 200km. These cities can uncombine in an emergancy (such as a Dark Forest Strike).

The biggest combined city so far was located at Neptune, where four of the eight cities were docked together along their axis of spin, forming a two-hundred-kilometer-long combined city. When necessary—such as when a dark forest strike alert was issued—the combined city could be quickly taken apart to increase the mobility of each city. People hoped that, one day, all the cities in each cluster could be combined into one, so that humanity would live in four complete worlds.

The space cities are in orbit around the Sun rather than around the gas giants they hide behind (so as to better protect them from a Dark Forest strike), and occasssionally they have to reactivate their thrusts and push away to avoid falling into the planets gravity).

One of the space cities in front suddenly emitted a blue light. It was as though a small blue sun appeared in space, casting long shadows of the people and spaceships on the plaza. Cao Bin told Cheng Xin that this was because the space city’s thrusters had been activated to adjust its position. The space cities revolved around the Sun in parallel with Jupiter, just outside its orbit. Jupiter’s gravity gradually pulled the cities closer, and the cities had to constantly adjust their positions with thrusters. This operation required a great deal of energy. Once, the suggestion had been floated to turn the cities into Jupiter’s satellites that would only shift into new orbits around the Sun after the issuance of a dark forest strike warning. But until the advance warning system had been further refined and proven to be reliable, no space city wanted to take the risk.

There are a total of 26 space cities in the Bunker World of Jupiter, with another 4 being planned for construction.

From here, most of the space cities behind Jupiter could be seen. She saw twenty-two cities (including the one she stood on), and there were four more blocked by the city they stood on. All twenty-six cities (six more than planned) were hiding in the shadow of Jupiter.

There are another 38 space cities in other Bunker Worlds behind the other gas giants; 26 behind Saturn, 4 behind Uranus and 8 behind Neptune.

Behind the other three gas giants were three more space city clusters, consisting of a total of thirty-eight space cities. Twenty-six were behind Saturn, four behind Uranus, and eight more behind Neptune. Those space cities were in safer locations, though the environs were even more desolate.

(All of the above is from Death's End)

 

[Stocking Anarchy]

Bathing in the Broadcast Era involves supersonic waves and cleaning agents composed of nanobots, which could be used with or without water.

Modern baths had nothing to do with bubbles. Soap and other similar toiletries had disappeared more than a century ago. Contemporary bathing practices involved two methods: supersonic waves and cleaning agents. Cleaning agents were nanorobots invisible to the naked eye. One could use them with or without water. They cleaned skin and other surfaces instantaneously.

 

[Stocking Anarchy]

In previous eras (such as the Broadcast Era), people had self-cleaning clothes. However, in the Bunker Era, such technology appears to no longer be in use.

During the last age Cheng Xin was awake, people wore self-cleaning clothes that always looked brand new, but this nurse’s white uniform showed signs of wear. Although it was still clean, she could see signs of it being old, signs of the passage of time.

 

[Stocking Anarchy]

Late in the Crisis Era, humanity has clothing which has changable images and patterns on them.

The face reappeared. It belonged to a man with a gentle expression who looked at Luo Ji and said, “Welcome to our era.” As he spoke, a field of vibrant roses flashed on his white lab coat, then gradually faded and disappeared. As he continued speaking, the coat displayed a continuous assortment of delightful images that matched his expressions and emotions: seas, sunsets, and woods in the drizzle.

The nurse came out of the changing room dressed in her own clothes. Aside from the flashing movies on the fabric, changes to women’s fashion in this age were well within the scope of Luo Ji’s imagination. Compared to his own era, the major difference was their conspicuous asymmetry. He was pleased that after 185 years had passed, he could still find beauty in women’s clothing.

(From The Dark Forest)

As of the Deterrence Era, only children dress in animated clothing.

“Before the Deterrence Era, clothes with animated images were popular. Back then, everyone looked like blinking Christmas trees, but now, only children dress like that. Classical looks are in vogue again.”

(From Death's End)

 

[Stocking Anarchy]

Cities in the Crisis Era are built underground and take the form of great forests.

Luo Ji turned his eyes downward and immediately became dizzy. From high up, it took him a long moment to realize that what he saw from here was the city. At first he thought he was looking at a giant forest, the slender tree trunks stretching straight up toward the sky, each one sprouting perpendicular branches of varying lengths. The city’s buildings were the leaves hanging off these branches. The layout of the city looked random, and different trees had different densities of leaves. The Hibernation and Reawakening Center formed a part of one of those large trees, and the leaf that contained his bed hung from the narrow platform that now extended out in front of him.
Looking back, the tree trunk his branch was connected to extended so far upward that it disappeared out of view. The branch they were on was located in the middle to upper section of the tree, and above and below them he could see other branches, and the structural leaves that hung on them. On closer inspection, the branches formed an intricate network of bridges in space, bridges with one end left floating in midair.
“What is this place?” Luo Ji asked.
“Beijing.”

The city of Beijing is 1km below the surface.

Seeing Luo Ji’s terrified look, she burst out laughing so hard that she
had to lean on the railing for support. “Ah, ha-ha. I forgot. I’m really sorry. I’ve forgotten so many times. Look, we’re underground here. A thousand meters beneath the surface ... If I ever get to time travel to your time, you can get back at me and forget to tell me that the city’s on the surface, and I’ll be as terrified as you are now. Ha ha ha...”
“But ... this...” He held up his hands.
“The sky is fake. The sun is fake, too,” the woman said, trying to suppress a smile. “Of course, saying it’s fake isn’t right, either, because it’s an image taken from an altitude of ten thousand meters and displayed down here, so maybe it counts as real, too.”
“Why build the city below ground? And a thousand meters—that’s really deep.”

(From The Dark Forest)

In the Deterrence Era, these giant tree buildings are built on the surface. Sophon's house is also able to generate a white cloud around it.

Sophon lived on a giant tree at the edge of the city. Viewed from the flying car, the leaves on the tree were sparse, as though it were late autumn. Sophon lived on the branch at the top, where a single leaf hung, an elegant dwelling made of bamboo and surrounded by a white cloud. The day was cloudless, and it was clear that Sophon’s house generated the white mist.

The tree building that Sophon lives in is 400m tall.

At its peak, the congregation was a group several times larger than that of pilgrims in Mecca, forming an endless sea. Sophon’s house hung in the air about four hundred meters above the crowd.

(From Death's End)

 

[Stocking Anarchy]

In the Halo space city, the soldiers posses rifles which can not only hit a target from 2000km away, but which contain antimatter inside each bullet.

“This is our city self-defense force.” Wade waved at the assembled men. “They are all we have to protect Halo City and the ideal of the lightspeed ship. You can see almost all of them here—there are a few more outside, but the total is no more than a hundred. As for their equipment—” Wade took a rifle from one of the soldiers and pulled the bolt. “You can trust your eyes: ancient weapons constructed of modern materials. The bullets do not rely on gunpowder as the propellant and have much better range and precision compared to genuine ancient weapons. In space, these rifles can hit a ship from two thousand kilometers away, but fundamentally, they’re
primitive weapons. You must think this ridiculous, and I would, too, except for one thing.” He returned the rifle to the soldier and pulled one of the cartridges from his bandolier. “As I said, the cartridges are basically of ancient design, but the bullets are new. So new, in fact, that they might as well come from the future. The bullet is a superconducting container and the interior is a pure vacuum. A magnetic field suspends a small ball in the middle to prevent it from contacting the bullet’s body. The ball is made of antimatter.”

The Halo space city used the circumsolar particle accelerator to make this antimatter, and they now posses over 15,000 of these bullets.

Bi Yunfeng’s voice was filled with pride. “The circumsolar particle accelerator was not only used for basic research experiments, but also to produce antimatter. In the last four years, we’ve used it to make antimatter practically the entire time. We now possess fifteen thousand bullets of this design.”

A single mishap would be enough to destroy the entire Halo space city.

She now worried about the reliability of the containment magnetic field within that superconducting bullet: a single malfunction would be enough to cause the complete destruction of Halo City in a brilliant flash.

A single antimatter bullet is enough to take out an entire warship. What's more, Halo has secret agents in multiple other space cities armed with antimatter bullets.

“We don’t even have to go into space to attack. We just have to wait until the fleet approaches the city. We can shoot dozens or even hundreds of bullets at each of the twenty or so ships—a single hit is enough to destroy it. Although the tactic is primitive, it’s effective and flexible. A single soldier with a gun is a fighting unit capable of threatening an entire warship. Also, we have agents in other space cities with handguns.”

A single one of these antimatter bullets would cause a massive explosion that would instantly tear apart the shell of a space city and incinerate everything within.

If war were to erupt, any of the guerrilla fighters hidden in the other space cities could casually shoot one of the antimatter bullets at the ground and the explosion of matter-antimatter annihilation would instantaneously tear apart the thin shell of the city and incinerate everything within. Next, the spinning space city would break into fragments and millions would die.
Space cities were as fragile as eggs.

(From Death's End)

 

[Stocking Anarchy]

The circumsolar particle accelerator is a colossal particle accelerator that spans the orbit of Jupiter. However, it's not one physical object, but 3200 coils in space, each a distance of about 1,500,000km from each other.

The dinghy stopped and hovered next to the ring. Cheng Xin estimated that the ring’s diameter was about two hundred meters across, and the band about fifty meters thick.
“You’re looking at the circumsolar particle accelerator,” Cao Bin said, his tone awed.
“It’s... rather small.”
“Oh, sorry; I wasn’t clear. This is but one of the coils in the particle accelerator. There are thirty-two hundred coils like this, each about one point five million kilometers apart, forming a large circle around the Sun in the vicinity of Jupiter’s orbit. Particles pass through the center of these coils, where they’re accelerated by the force field generated by the coil toward the next coil, where they’re accelerated again.... A particle might travel around the Sun multiple times during the process.”

The circumsolar particle accelerator can accelerate a particle to the energy level of the Big Bang (in this case, I believe this means 'the level that individual particles possessed during the Big Bang rather than 'energy equal to the birth of a universe'). Even as such, the energy is tremendous; once a lost freighter passed through the orbit and was instantly vaporized, along with it's several million tons of mineral ore.

“This is a supercollider capable of accelerating a particle to the energy level of the big bang. Ships are not allowed anywhere near the orbit of the accelerator. A few years ago, a lost freighter drifted into the orbit by mistake and was hit by a beam of accelerated particles. The ultrahigh- energy particles struck the ship and produced high-energy secondary showers that vaporized the ship and its cargo of millions of tons of mineral ore in an instant.”

 

[Stocking Anarchy]

Dualpoint-Vector Foil (or 2D foil) is the most terrifying weapon in the known universe. It can collapse objects in the third dimension into the second dimension. It is launched by an entity known as Singer, as using a mass dot (photoid) might leave something behind..

The only thing left was cleansing. Singer took a mass dot out of the magazine again, then realized that he couldn’t use a mass dot to cleanse the Star-Pluckers. Their planetary system had a different structure than the dead world’s system: it possessed blind corners. Using a mass dot might leave something behind, thereby wasting effort. He needed to use a dual-vector foil. However, Singer didn’t have the authority to retrieve a dual-vector foil out of the magazine; he had to ask the Elder for approval.
“I need a dual-vector foil for cleansing.”
“Permission granted,” said the Elder.
The dual-vector foil drifted in front of Singer. It was sealed in its
package, crystal clear. Although it was an ordinary object, Singer liked it a lot. He didn’t like the expensive tools too much; they were too violent. He liked the unyielding tenderness displayed by the dual-vector foil, a kind of aesthetic that could turn death into a song.

The 2D foil starts to unfold, converting everything that touches it into a 2D plane with no depth. Just as 4D space can unfold into 3D space, 3D space unfolds into 2D space.

“General, you once said, ‘I don’t think it’s anything. There’s nothing inside.’ You were right. That slip really wasn’t anything, and contained nothing. It’s only space, just like the space around us, which isn’t anything and contains nothing. But there’s a difference: It’s two-dimensional. It’s not a block, but a slice. A slice without thickness.”
“Hadn’t it evaporated?”
“The protective field around it evaporated. The force field acted like packaging that separated the two-dimensional space from the three- dimensional space. But now the two are in direct contact. Do you remember what Blue Space and Gravity saw?”
No one answered, but they all remembered: the four-dimensional space falling into three dimensions, like a waterfall off a cliff.
“Just as four-dimensional space collapses into three dimensions, three- dimensional space can collapse into two dimensions, with one dimension folding and curling into the quantum realm. The area of that slice of two-dimensional space—it only has area—will rapidly expand, causing more space to collapse.... We’re now in space that is falling toward two dimensions, and ultimately, the entire Solar System will follow. In other words, the Solar System will turn into a painting with no thickness.”

The escape velocity of the 2D foil is the speed of light, and thus only a curvature lightspeed engine can be used to escape it.

“What is the escape velocity?”
“I’ve computed it four separate times. Pretty sure I got it right.”
“What is it?!”
Everyone aboard Revelation and Alaska held their breaths and listened
to this final calculation as representatives of humanity. Ice calmly announced his judgment. “Lightspeed.”

The entire Solar System within the Kuiper belt will collapse into the 2nd dimension in 8 to 10 days.

“The entire Solar System within the Kuiper Belt will collapse into two dimensions in eight to ten days.”

The attack takes the form of a dimensional strike, which will collapse the space around the Solar System from three dimensions to two dimensions. The result will be the complete destruction of all life.
The process is estimated to take eight to ten days. At this moment, the collapse is ongoing and the rate and extent of collapse are rapidly growing.
We have confirmed that the escape velocity for the collapsing region is the speed of light.

Neptune and Saturn are converted to 2 dimensions.

A pair of giant eyes stared down at them from space.
Two glowing ovals hung in space, looking exactly like eyes. The “whites” were white or light yellow, and the “irises” were dark.
“That’s Neptune, and the other one is Ura—oh, no, that’s Saturn!” AA said.
Both gas giants had been two-dimensionalized. Uranus’s orbit was outside Saturn’s, but since Uranus was currently on the other side of the Sun, Saturn had fallen into the two-dimensional plane first. The giant planets ought to look like circles after collapsing, but due to the angle of view from Pluto, they appeared as ovals. The two-dimensional planets showed up as clear, concentric rings. Neptune consisted mainly of three rings: the outermost was blue, bright and vivid, like lashes and eye shadow —that was the atmosphere of hydrogen and helium. The middle ring was white—that was the twenty-thousand-kilometer mantle, which astronomers thought of as a water-ammonia ocean. The dark center was the core, formed of rocks and ice, with a mass equal to the entire Earth. Saturn’s structure was similar, except it didn’t have the outer blue ring.
Each large ring was composed of many smaller rings, full of detailed structures. As they examined the planets further, the two giant eyes now more resembled the rings of a newly felled tree. Around each two- dimensional planet were a dozen or so small circles—moons that had also been flattened. Around Saturn was another faint large circle—its rings. They could still find the Sun in the sky, a small disk emitting faint yellow light. Since the two planets were still on the other side of the sun, their area after collapsing into two dimensions was breathtaking.
Both planets had no thickness anymore.

The Sun itself unravels into the 2nd dimensional plane, its blazing power affecting the rest of the flattened Solar System with it's power and gravity.

As soon as the Sun began to two-dimensionalize, a circle expanded on the plane. Soon, the planar Sun’s diameter exceeded the diameter of the remaining part of the Sun. This process took only thirty seconds. Based on the mean solar radius of seven hundred thousand kilometers, the rim of the two-dimensional Sun grew at the rate of twenty thousand kilometers per second. The planar Sun continued to grow, forming a sea of fire on the plane, and the three-dimensional Sun sank slowly into this blood-red sea of fire.
Four centuries ago, Ye Wenjie had stood on the peak of Red Coast Base and watched such a sunset during the last moments of her life. Her heart had struggled to beat like a zither string about to break, and a black fog had begun to cloud her eyes. On the western horizon, the Sun that was falling into the sea of clouds seemed to melt, and the Sun’s blood seeped into the clouds and the sky, creating a large crimson swath. She had called it humanity’s sunset.
And now, the Sun really was melting, its blood seeping into the deadly plane. This was the last sunset.
In the distance, white fog rose from the ground outside the landing field. Pluto’s solid nitrogen and ammonia sublimated, and the fresh, thin atmosphere began to scatter the sunlight. The sky no longer appeared pure black, but showed hints of purple.
While the three-dimensional Sun was setting, the two-dimensional Sun was rising. A flat star could still radiate its light inside the plane, so the two- dimensional Solar System received its first sunlight. The sides of the four two-dimensional planets facing the sun—Neptune, Saturn, the Earth, and Mercury—all took on a golden glow, though the light only fell along a one-dimensional curved edge. The giant snowflakes that surrounded the Earth melted and turned into white vapor, which was blown by two-dimensional solar wind into two-dimensional space. Some of the vapor soaked up the golden sunlight and appeared as if the Earth had hair that drifted with the wind.
An hour later, the Sun had completely collapsed into two dimensions.

After the collapse into the 2D plane, parts of the outermost layers of the solar atmosphere escape the Sun, and drift off further into the two-dimensional universe.

The outermost layer was the solar atmosphere. Golden currents leapt away from the circular rim and formed a large number of two-dimensional prominences, resembling graceful dancers cavorting wantonly around the Sun. Some of the “dancers” even escaped the Sun and drifted far into the two-dimensional universe.

The Sun in the 2nd dimension quickly looses it's light, and it affects the flattened planets of the Solar System with it's gravity.

The flattened Sun began to dim. The light from the core diminished rapidly and soon it was possible to see fine annular structures within. The radiation zone was also quieting, and the boiling calmed down, turning into a viscous peristalsis. The loops in the convection zone distorted, broke apart, and soon disappeared. The golden dancers around the rim of the Sun wilted like dried leaves and lost their vivaciousness. Now it was possible to tell that at least gravity continued to function in the two-dimensional universe. The dancing solar prominences lost the support of solar radiation and began to be dragged back to the edge of the Sun by its gravity. Finally, the dancers yielded to gravity and fell lethargically, until the Sun’s atmosphere was no more than a thin, smooth ring wrapped around the Sun. As the Sun went out, the golden arcs at the edges of the planets also dimmed, and the Earth’s two-dimensional hair, formed from the sublimated ocean, lost its golden glow.

It is possible that life exists in the 2D universe, but it would have to be created and operate under completely different laws to the 3rd dimension.

Perhaps a two-dimensional universe could possess its own sun, planets, and life, but they would have to be created and operate under completely different principles.

The space city of Europe VI collapses into the 2nd dimension in less than 10 minutes.

The lonely, three-dimensional island continued to sink and melt into the two-dimensional sea. In less than ten minutes, all of Europe VI had turned into a painting.

Such is the unravelling of the Solar System that every individual atom is unfolded on the depthless plane.

The painting of Europe VI was so vast that it was hard to estimate its exact area. It was a dead city, but perhaps it was more accurate to call it a 1:1 drawing of the city. The drawing reflected every detail of the city, down to every screw, every fiber, every mite, and even every bacterium. The precision of the drawing was at the level of the individual atom. Every atom in the original three-dimensional space was projected onto its corresponding place in two-dimensional space according to ironclad laws. The basic principles governing this drawing were that there could be no overlap and no hidden parts, and every single detail had to be laid out on the plane.

However, the most terrifying aspect of the Dualpoint-Vector Foil is the fact it does not stop. Eventually, it will reach those who launched the attack, and their world will fall into the 2nd dimension too.

“I thought of something I wanted to ask you. When will the collapse of space in the vicinity of the Solar System into two dimensions cease?”
“It will never cease.” Cheng Xin shuddered.
“You are scared? Do you think that in this galaxy, in this universe, only the Solar System is collapsing into two dimensions? Haha...”
Guan Yifan’s bitter laughter caused Cheng Xin’s heart to seize up. She said, “What you’re saying makes no sense. At least, it doesn’t make sense to lower spatial dimensions as a weapon. In the long run, that’s the sort of attack that would kill the attacker as well as the target. Eventually, the side that initiated attack would also see their own space fall into the two-dimensional abyss they created.”

The only known way to survive this attack is to transform oneself, so as to be able to survive in the 2D universe.

“There’s a way for the attacker to avoid death. Think about it.”
Cheng Xin pondered and then said, “I can’t figure it out.”
“I know you can’t. Because you’re too kind. It’s very simple. The attacker must first transform themselves into life forms that can survive in a low-dimensional universe. For instance, a four-dimensional species can transform itself into three-dimensional creatures, or a three-dimensional species can transform itself into two-dimensional life. After the entire civilization has entered a lower dimension, they can initiate a dimensional strike against the enemy without concern for the consequences.”

This seems to be exactly what the race of Singer was planning (or had already done).

“Has the home world decided to transform into two dimensions?” Singer asked. Of course, the Elder already knew the question.
The Elder did not answer, which was also an answer.
If the rumor was true, then it was a great sorrow. Singer couldn’t imagine such a life. On the tower of values, survival ranked above all. When survival was threatened, all low-entropy entities could only pick the lesser of two evils.

(All of the above is from Death's End)

 

[Stocking Anarchy]

A spaceship with lightspeed curvature engines can warp the very fabric of space itself, and these can range in size from 15 AU to 200 AU.

The curvature trails were left behind when ships entered lightspeed, just as a rocket launching from the ground left burn marks on the launch pad. Once the ship was at lightspeed, it continued to coast by inertia, and left no more trails. It was a reasonable conjecture that dropping out of lightspeed would leave behind similar marks. It was still unknown how long such trails would persist in space. A guess was that the trails represented some kind of distortion in space due to curvature propulsion, and might last a long time—maybe even forever.
It was reasonable to conclude that Sophon had claimed Trisolaris appeared more dangerous than the Solar System when observed from a distance because of the ten-AU-diameter curvature propulsion trail left behind within the Trisolaran system, which is what caused the dark forest strike against Trisolaris to come so quickly. The trail and the broadcast of Trisolaris’s location mutually provided confirmation and made the danger value of the Trisolaran system skyrocket.
During the following month, Observation Unit #1 discovered six more curvature propulsion trails in different parts of space. All of these were approximately spherical, though their sizes varied widely, ranging from fifteen to two hundred AU. One of these bubbles was only six thousand AU from the Solar System, apparently the mark left by the Second Trisolaran Fleet as it dropped out of lightspeed. The directions and distances of the other trails, however, seemed to indicate that they had nothing to do with the Second Trisolaran Fleet. It appeared that curvature propulsion trails were common in the universe.

In the wake of these curvature engines, the speed of light itself is slowed, as space itself is being warped. For example, in the Halo's wake, the speed of light in the vaccuum is lowered to 16.7km a second.

“That’s right. It’s the same principle with lightspeed ships. The very structure of space itself is changed by the trail of a curvature-propelled ship. If a second curvature-propelled ship were placed inside the trail of the first, it would hardly move. Within the trails of lightspeed ships, one must use a more powerful curvature propulsion drive. It would still be possible to use curvature propulsion to achieve the highest speed possible within such a space, but the maximum velocity is much lower than the maximum velocity of the first ship. In other words, the speed of light through vacuum is lowered within the trail of lightspeed ships.”
“How much lower?”
“Theoretically, it could be reduced to zero, but that’s not achievable in reality. But if you adjust the curvature ratio of Halo’s engine to the maximum, you can lower the speed of light in its trail down to exactly what we’ve been looking for: sixteen point seven kilometers per second.”

At the speed of light, a journey of 287 lightyears takes 52 hours (even though outside, 287 years have passed).

AA’s words slid across Cheng Xin’s thoughts like drops of water across a lily pad, leaving no trace. Cheng Xin’s only thought was to find Yun Tianming and tell him everything. In her mind, a journey of 287 light-years would take a long time, but the ship’s AI informed her that the trip would only take fifty-two hours in the ship’s frame of reference. Everything felt unreal to Cheng Xin, as though she had already died and gone to another world.

 

[Stocking Anarchy]

Within 3D space space are small areas (or relatively small, as each area is still many AUs across) of surviving areas of 4D. This dimension isn't truly lost, as it will curl up with the other higher dimensions in the quantum realm. All higher dimensional matter, however, will be unfolded into the 3rd dimension. Something a mere few tens of grams in 4D space can be unfolded across 10,000s of km in 3D space.

After analyzing the data, Guan and the science officers concluded that the lines were created by four-dimensional matter entering three-
dimensional space. As the fragment shrank, four-dimensional matter dropped into three-dimensional space and decayed instantly. Although these bits of matter took up very little volume in four-dimensional space, their decay into three dimensions flattened the fourth dimension, causing their volume to increase greatly and expand into the form of straight lines. By their calculations, a few tens of grams of four-dimensional matter could form a line stretching almost ten thousand kilometers in three dimensions.
Based on the rate at which the boundary of the fragment was receding, in twenty days or so, the Ring would also enter three-dimensional space.

During the next dozen or so days, Guan Yifan was absorbed in deep thought and calculations, and the science officers engaged in vigorous debates. Finally, they reached the consensus that, based on current theoretical physics, they could not do too much theoretical analysis of the four-dimensional fragment. But the theories that had been developed in the past three centuries could at least make some predictions that were confirmed by observations: A higher dimension existing in macro form decayed toward lower dimensions as inevitably as water fell over a cliff. The decay of four-dimensional space into three dimensions was the root cause of the fragment’s shrinking.
But the lost dimension wasn’t truly lost: It simply curled up from the macroscopic to the microscopic and became one of the seven dimensions folded up within the quantum realm.