SPOILERS THO

The three-body problem in physics states that although it is trivial to model the path of two bodies (e.g. binary stars) revolving around each other, it is currently impossible to create a model that can accurately predict the future positions of three bodies around each other, as minute instabilities add up over time to create a chaotic system. This book postulates that the nearest star to the earth, Alpha Centauri, as a ternary star system, is such a chaotic system; despite its unpredictability, a race of sentient species have evolved to sentience on an immensely inhospitable planet. When they learn of the existence of Earth, and realize it is in a stable solar system with a relatively mild climate, what would such a civilization do?

The book reminds me of Carl Sagan's "Contact" (well, the movie; I haven't read the book) but goes beyond the touchy-feely aspects of Sagan's work. Contact is distinctly American, and therefore, deeply religious; when Arroway finally meets aliens, the interaction is solely a personal one, which occurs without any observable proof that it took place at all. With that experience, Arroway is humanity's messiah, able to spread the message that the promised land is a space paradise of hob-nobbing with other, enlightened spacefaring species — if you have faith. 3BP dispenses with the notion that the space age will be a lovely vacation earned by a well-behaved humanity. I don't know if it's because the author takes a very hard-science approach or it's more of a Chinese cultural influence, but the characters in 3BP don't think of joining the aliens because they believe they're worthy. On the contrary, they invite the (presumably enlightened) aliens to Earth as a corrective measure: we're flawed, we're broken, we need your help, come fix us.

Of course, even that ends up being wildly optimistic, as the aliens don't really care about mentoring humans at all. They just want a planet with an easier difficulty level to live on. The universe is a harsh and unforgiving place, and it turns out that outer space isn't the paradise, Earth is. And the aliens wants it for themselves. So, well, they kind of do the science equivalent of driving down the property values so they can swoop in and buy up all the land at a super low price by the time their moving vans get there. (It'll take about 450 years, at a maximum of 10-percent of the speed of light.)

The book ends there. Not with a proclamation of some glorious, kumbaya future, or even a clear evil to be defeated, just a slowly ticking clock. Earth will be occupied in 450 years by star-hopping alien gentrifiers just trying to find a new backyard in which to raise their alien babies. So what now?