“The Three-body Problem”: The Sci-fi Book

 Review

“My sunset,” Ye whispered. “And sunset for humanity.”

The novel ends with an anticipation filled with fear of the coming events which no character are going to experience in their lifetime. In fact the fear was not from any kind of threat to any person on earth; this is an would be threat for the whole humanity. Even though it is not dawn yet but it is visible. Can they do something about it?

People have been thinking about three body problem for centuries with significant progress by mathematicians and physicists such as Laplace, Legendre, Poincare, Kolmogorov, Arnold. The rise of computers had provided important tools to understand many qualitative aspects and few particular stable solutions of this problem.

In essence, the problem is as follows. Newton’s laws of motion and gravitation is sufficient to find the future configuration (i.e. 3 positional coordinates and 3 velocities of each particles; total 6N numbers of N particles) if a system of particle under mutual gravitational influence provided we know the configuration to infinite precision. For a two-body system this problem has an analytical solution which allows us to compute the configurations at any time in future to a desired accuracy. Just by adding another body in the problem makes the system what we now call chaotic. Not only the so called three-body problem doesn’t have a closed form solutions, it’s also extremely sensitive to the initial conditions. The last phrase means that the numerical computations are also useless to find the configurations beyond a given time-interval, generally specified by the precision of initial configurations for a given system. Since, by definition we can’t represent the initial configurations to infinite precision, we cannot know the behaviour of such system in an arbitrary future. The same can be said for a system of N particles under mutual gravitation.

Poincare devised topological view of this problem and showed that even if we cannot compute, we can understand many qualitative features of its evolution. Later Kolmogorov, Arnold and Moser (KAM) proved a theorem regarding a general N-body periodic system. The KAM theorem find the conditions under which an N-body system would be stable and will not wander away and do something crazy. This result was helpful in understanding the long-term behaviour of our solar system.

Cixin Liu takes this intricate chaotic madness of physical equations and add the messiness of conscious beings to give us a hard science fiction on soft side — The Three-Body Problem. He does this by adding a planet inhabited by living beings. This planet is gravitationally bound to a three-star system doing the chaotic dance. This makes the planet frequented by extreme weather conditions from lava flowing on the surface to ultra-cold temperature. The novel, however, doesn’t go into the question of how is it possible for the complexities of biological life to evolve under such variations in the environmental conditions. The planet is inhabited by being who can dehydrate their body and keep it safe for centuries in case of “chaotic era” (extreme weather) and hydrate again to enjoy
“stable era”. Stable era is also the time of great progress, scientific or otherwise. They have managed to survive through thousands of major annihilation to reach a scientifically advanced stage where they can manipulate extra dimensions hidden in elementary particles for the technological use. But, they are in danger. The chaotic behaviour has caused all planets to fall in either of the three stars except this one and it’s going to happen. They are looking for another world, possible with long-periods of stable era or, only stable era. What could that be?

On Earth, during Chinese revolution, a disillusioned astrophysicist sends a signal in space by amplifying it using Sun’s inner radiation layer. Ignorant of the existence of civilisation, she receives a signal — “This world has received your message.
I am a pacifist in this world. It is the luck of your civilization that I am the first to receive your message. I am warning you: Do not answer! Do not answer!! Do not answer!!!
There are tens of millions of stars in your direction. As long as you do not answer, this world will not be able to ascertain the source of your transmission.
But if you do answer, the source will be located right away. Your planet will be invaded. Your world will be conquered!
Do not answer! Do not answer!! Do not answer!!!”.
She replies anyway. What happens further is carefully designed thriller which doesn’t end in just one volume.

The existence of extra dimension and their manipulation is still speculative science with even some mathematical indications against it. Using it in a science fiction always brings Star Wars kind of science fantasy in the author. Several details of it have been made up to provide nice visual image in the mind of the reader. However, it could be a source of irritation for the fans of hard science fiction.

One of the interesting existential thoughts come in the novel when the listener on the trisolaris asks the meaning of his life. Indeed this is everlasting pain in a human mind and believed to exist in any intelligent and self-conscious being unless they have gone past a certain threshold in their exploration. A contact with another intelligent being is definitely going to help us have more faith in “existence precedes meaning” mantra. This will further allow us to go beyond existentialism and face some of the philosophical problems of a self-conscious man evolved as a social being.

How can humanity redeem itself from the crimes it has done to itself and to the environment? Is there any esacape, or the nature would have to give punishment? Or, may be the only emancipation comes from sacrificing the whole humanity. Cixin gives us perspective about the bounties of nature and how are we misusing it without thought.

 

Interesting Excerpts From: Cixin Liu. “The Three-Body Problem.:

• “As she continued to mull over these thoughts, a deduction made her shudder: Is it possible that the relationship between humanity and evil is similar to the relationship between the ocean and an iceberg floating on its surface? Both the ocean and the iceberg are made of the same material. That the iceberg seems separate is only because it is in a different form. In reality, it is but a part of the vast ocean.…
  It was impossible to expect a moral awakening from humankind itself, just like it was impossible to expect humans to lift off the earth by pulling up on their own hair. To achieve moral awakening required a force outside the human race.
  This thought determined the entire direction of Ye’s life.”
•  “All the evidence points to a single conclusion: Physics has never existed, and will never exist. I know what I’m doing is irresponsible. But I have no choice.”
• “Can the fundamental nature of matter really be lawlessness? Can the stability and order of the world be but a temporary dynamic equilibrium achieved in a corner of the universe, a short-lived eddy in a chaotic current?”
• “The thought turned and turned in Wang’s head. Why would the path of the sun through the world of Three Body be devoid of regularity and pattern? Whether a planet’s orbit is more circular or more elliptical, its motion around its sun must be periodic. Total irregularity in planetary motion is impossible.… Wang grew angry with himself. He shook his head, trying to chase away these thoughts. It’s only a game! But I lost.”
• “Oh, I didn’t go to become a monk. Too lazy for that. I just wanted to find a truly peaceful place to live for a while. The abbot there was my father’s old friend—very intellectual, but became a monk in his old age. The way my father told it, at his level, this was about the only way out. The abbot asked me to stay. I told him, “I want to find a peaceful, easy way to just muddle through the rest of my life.” The abbot said, “This place isn’t really peaceful. There are lots of tourists, and many pilgrims too. The truly peaceful can find peace in a bustling city. And to attain that state, you need to empty yourself.” I said, “I’m empty enough. Fame and fortune are nothing to me. Many of the monks in this temple are worldlier than me.” The abbot shook his head and said, “No, emptiness is not nothingness. Emptiness is a type of existence. You must use this existential emptiness to fill yourself.” His words were very enlightening to me. Later, after I thought about it a bit, I         realized that it wasn’t Buddhist philosophy at all, but was[…]”
• “Everyone seems to believe that Poincaré proved that the three-body problem couldn’t be solved, but I think they’re mistaken. He only proved sensitive dependence on initial conditions, and that the three-body system couldn’t be solved by integrals. But sensitivity is not the same as being completely indeterminable. It’s just that the solution contains a greater number of different forms. What’s needed is a new algorithm.
• Back then, I thought of one thing: Have you heard of the Monte Carlo method? Ah, it’s a computer algorithm often used for calculating the area of irregular shapes. Specifically, the software puts the figure of interest in a figure of known area, such as a circle, and randomly strikes it with many tiny balls, never targeting the same spot twice. After a large number of balls, the proportion of balls that fall within the irregular shape compared to the total number of balls used to hit the circle will yield the area of the shape. Of course, the smaller the balls used, the more accurate the result. Although the method is simple, it shows how, mathematically, random brute force can overcome precise logic. It’s a numerical approach that uses quantity to derive quality. This is my strategy for solving the three-body problem. I study the system moment by moment. At each moment, the spheres’ motion vectors can combine in infinite ways. I treat each combination like a life form. The key is to set up some rules: which combinations of motion vectors are “healthy” and “beneficial,” and which combinations are “detrimental” and “harmful.” The former receive a survival advantage while the latter are disfavored. The computation proceeds by eliminating the disadvantaged and preserving the advantaged. The final combination that survives is the correct prediction for the system’s next configuration, the next moment in time.”
• “Buddha, please help my Lord break away from the sea of misery.”
• “Against the background of the three suns in syzygy, text appeared: Civilization Number 184 was destroyed by the stacked gravitational attractions of a tri-solar syzygy. This civilization had advanced to the Scientific Revolution and the Industrial Revolution. In this civilization, Newton established nonrelativistic classical mechanics. At the same time, due to the invention of calculus and the Von Neumann architecture computer, the foundation was set for the quantitative mathematical analysis of the motion of three bodies. After a long time, life and civilization will begin once more, and progress through the unpredictable world of Three Body. We invite you to log on again.”

• “Eventually, I lost hope in the human race and joined the ETO. Desperation turned me from a pacifist into an extremist. Also, probably because I donated so much money to the Organization, I became a core member of the Adventists. Let me tell you now, the Adventists have their own secret agenda.
  “And it is this: The human race is an evil species. Human civilization has committed unforgivable crimes against the Earth and must be punished. The ultimate goal of the Adventists is to ask our Lord to carry out this divine punishment: the destruction of all humankind.”
• “This time, after the Jovian radio outbursts reached the sun, they were re-emitted, as if by a mirror, after being amplified about a hundred million times. The Earth received both sets of emissions, before and after the amplification, separated by sixteen minutes and forty-two seconds. The sun was an amplifier for radio waves.”

• “This world has received your message. I am a pacifist in this world. It is the luck of your civilization that I am the first to receive your message. I am warning you: Do not answer! Do not answer!! Do not answer!!!
  There are tens of millions of stars in your direction. As long as you do not answer, this world will not be able to ascertain the source of your transmission.
  But if you do answer, the source will be located right away. Your planet will be invaded. Your world will be conquered!
  Do not answer! Do not answer!! Do not answer!!!”

 

• “YE: Yes, I meant subatomic particles. Six years ago, in the distant Trisolaran stellar system, Trisolaris accelerated two hydrogen nuclei to near the speed of light and shot them toward the solar system. These two hydrogen nuclei, or protons, arrived at the solar system two years ago, then reached the Earth.
  INTERROGATOR: Two protons? They only sent two protons? That’s almost nothing.
  YE: (laughs) You also said “almost.” That’s the limit of Trisolaran power. They can only accelerate something as small as a proton to near the speed of light. So over a distance of four light-years, they can only send two protons.
  INTERROGATOR: At the macroscopic level, two protons are nothing. Even a single cilium on a bacterium would include several billion protons. What’s the point?
  YE: They’re a lock.
  INTERROGATOR: A lock? What are they locking?
  YE: They are sealing off the progress of human science. Because of the existence of these two protons, humanity will not be able to make any important scientific developments during the four and a half centuries until the arrival of the Trisolaran Fleet. Evans once said that the day of arrival of the two protons was also the day that[…]”

 

• “In the last few years, the listener had asked himself millions of times: Is this all there is to my life? And millions of times he had answered himself: Yes, this is all there is. All that you have in this life is the endless loneliness in the tiny space of this listening post.
  He couldn’t lose that paradise, even if it was only in a dream.”
• “My sunset,” Ye whispered. “And sunset for humanity.”