Category Archives: Books, I Read


It is easy to imagine how wars fight in cosmos, giant spaceship shoot each other by laser light, Jedi Knight cut each other with their light saber, or throwing nuclear bomb to enemies. All these methods are just “too simple, sometimes naive.”

In Liu Cixin’s Three-body Trilogy, the wars between human and aliens are just like an art, and beyond one’s wildest mind.

The first war in universe happened in solar system, earth sent almost all the spaceships fleet to catch a single probe send by Three-body civilization. The spaceships were well equipped, with all kinds of sci-fi weapon. While, the probe is simple, looks like a droplet, the surface is more smooth than mirror. Even under a 10,000,000x microscope, there is no flaw on it. It’s absolutely beyond human technology, like the black Monolith in Space Odyssey. And soon, the droplet destroy entire space fleet by hit. Simple and brutal.

Comparing with Dark Foresthit, droplet attack is nothing but a children’s game. Dark Forest hit means eliminate a solar system, to make sure civilization can not live any more.So far as we know, there are two ways to do that. One is using “Photin” hitting star directly, with the explosion of solar, destroy everything in solar system. But, there is way to defense this kind hit, by hiding behind giant planet like Jupiter or Saturn.

The other kind of Dark Forest is romantic. In the novel. An unknown civilization sent a “Difoil” to solar system. It looks like a piece of paper. However, it brings a “Dimensional”atteck. Transfer our system from three dimensional space to two dimensional  space, just as van Gogh’s Starry Night. No one can live in 2D solar system.

What’s really terrified in novel is Liu predicts senior civilization could use physics laws to lunch attack, or even math laws.

It seems a bad idea to communicate with aliens. Anyway, don’t panic, our earth is most harmless.

Dark Forest Theory


“Dark Forest” is a fiction cosmos sociology theory from Three-body II: Dark Forest, second part of a Sci-fiction Trilogy written by Liu Cixin. Dark Forest Theory describes a condition in cosmos, and explained why human can hardly find aliens. This theory is the core of the novel, even in Three-body III: Dead End.

The point about the whole universe is:

The universe is like a dark forest where every civilization is a hiding hunter; anyone exposed will be attacked and destroyed.

Exactly Speaking, Dark Forest contains two main concepts: 1) Suspicious Chain; 2) Technology Explosion.

The universe is large. The distance  between separated civilization can only counted by light year,  and the differences between civilization could beyond people’s wildest imagination. Under such circumstance, it is hard to communication, and impossible to judge other civilization are good or evil(good here means does not lunch attack other civilization, evil means the opposite). Communication in universe is a dangerous thing, it means be exposed,  detceted or even located by aliens(good or evil).

Even one intend to take their chance, assume others are good, and if both civilization are good, they could set up a union or sth. But when others received such a message, they need to judge as well.

For instance, civilization A is good, so does civilization B, but they don’t know each other. First, A send a message to B, B have no idea if A is good or evil. Even they know, B still don’t know how A think B. Furthermore, B don’t know how A think B think A think B. Actually. It’s an endless loop, one couldn’t tell other’s intention.

The essential of Suspicious Chain is regardless the moral of civilization in galaxy, when they come into the web of Suspicious Chain, they have no difference.

How about B is weak, cannot threaten A? Here comes the second concept: Technology Explosion. From human history, our modern achievement are finished in last 300 years. Think about through universe’s view, it’s not  a development, it’s definitely a explosion. And surely we are not the fastest civilization. When B noticed the exist of A, it’s own technology could  be accelerated. A might be exceed, located , and even attacked. Thus, at the moment A detected B, A will  destroy B immediately one day B might find A too.

Generally, when A find B, it is extremely dangerous for A no matter let B noticed the exist of A, or leave B alone. A can either communicate or remain silence, the only option left is eliminate B quitly.

We human are still at the infant period of galaxy civilization, universe is a mystery to us. Stephen William Hawking also warned human should stop sending messages to find E.T. in universe for the same reason. May be it is true:

The universe is like a dark forest where every civilization is a hiding hunter; anyone exposed will be attacked and destroyed.

The Three-body Trilogy by Liu Cixin

Three-body Trilogy

Liu Cixin, who is a senior computer engieer works in Niangziguan Power Station(located in a small town in Shanxi Province), use his leisure time to write Sci-fiction novels. His works never fail to amaze me, sometimes are absolutly byond my wildest imagination about universe, especially after I read his latest work: Three-body III: Deadend. It is possible that Deadend is the final part of his “Three-body” trilogy.

The trilogy is consisted by Three-body, Three-body II: Dark Forest, Three-body III: Deadend. After finish the whole series, I got a feeling that anything is nothing, and sometimes when I look at stars in the sky,  it terrified me.

The story of Three-body Trilogy starts from the death of Ye Wenjie(叶文洁)’s farther, Ye Zhetai(叶哲泰), a physics professor in Tsinghua University during Culture Revolution in China. His death was caused by insisting E=mc^2. Ye Wenjie witness her father’s tragedy and herself was send to a secret base named “Hong An”(红岸,Red Coast) for her college major- astronomy.

After years of hard work, her loyalty have been proved and was told the truth about the Hong An Base. The Base was built for searching Aliens in Universe, just like SETI. In 1971, Ye Wenjie got an opptunity, she send messages through the sun, which could amplfies the signal largly.

Eight Years later, she received a reply from Three-body system which is 4 lightyears from Earth, the message was simple: DO NOT REPLY, OR WE WILL FIND YOU AND ATTACK. Unfortunatly, Ye Wenjie ignore this warning for she had disappointed at all human beings, and she expected aliens could bring hope to people. Also, she kept this secret and no doubt she is the first people touch alien civilization.

With the secret had been kept, Hong An had been dismissed for the change of time. Ye go back to her university and start her teaching career. Years later, she met an American, named Evans, who is also disappointed at humans. She shared her secret to him. And Evans built a ship as “Hong AN II” and he recruited some believers, many of these are elites.

In the mean time, two intellect protons(called Zhizi in later days) have send to Earth by Three-body System. Their job is to lock down human’s development of science by influent the result of physicial experiment. The unstable output of experiment cause serious problems, as scientists started questioning their own value system, some of them try to suicide.

Here the story began…

In this trilogy, the aliens never show up, Liu never told his reader what are those ET looks like, but he use many pages to illustrate their culure, which linked to Three-body system. More importantly, in the second book, after the first approach, Liu start to unveil the truth about our universe, universe is like nothing but a “dark forest”, civilization inside are facing great danger all the time( I may explain this theory next time). In the final book, the whole truth about this cruel universe have been showed to his reader.

Anyway, Liu’s trilogy is the best sci-fi novel I’ve ever read, his universe is just like Hawking’s, suggest that human should never try to contact E.T., or we will be in danger.