Alien Invasion, No Wormhole

What if Earth found out that an Alien Invasion was approaching but that the extra-terrestial fleet would only arrive several centuries from now? How might humankind react? How would Earth prepare? Would it precipitate chaos? Would it foster unprecedented international cooperation against a common invading foe? What technologies should be pursued?

This is the premise of The Dark Forest, the second book in Cixin Liu’s epic sci-fi trilogy that began with The Three-Body Problem. There is an unfolding scenario that attempts to provide a possible answer to the Fermi Paradox, hence the title of the book. But most of the story focuses on how Earthlings respond, at least in the first couple of centuries while ‘waiting’ for Doomsday.

There are some parameters to the situation. Some familiar, others less so. The alien technology is far superior to Earth’s at the time of discovery. No surprise there. However, wormhole or teleportation technology is not yet possible, so the main invasion fleet will take time to arrive as they can only travel some reasonable fraction of the speed of light. Earth’s technology can potentially deduce something about the aliens through deep-space astronomical observation, but is limited to the speed of light. To see something several light-years away requires several Earth years to pass. There is a lot of waiting.

The alien force has mastered certain quantum technologies, and have sent exceedingly low-mass ‘probes’, that can travel close to light-speed, which arrive at Earth only in several years. These probes can then communicate information instantaneously between the alien fleet and Earth via quantum entanglement. It allows the aliens to listen in on all Earth communications, and even communicate messages to Earthlings if needed. And yes, there is a human faction on Earth that welcomes the alien invasion and works to smooth its arrival. There are of course interesting wrinkles because aliens think and communicate differently from humans, and have different historical social structures.

The ‘probes’ can also mess up human scientists’ physics experiments at the quantum level thereby limiting the advancement of Earth technologies beyond a certain point. If you can’t repeat results in your scientific experiments, it is hard to discover fundamental theory that may lead to paradigmatic technological breakthroughs. Earth has one hand tied behind its back, so to speak. Choices have to be made as to which technologies are worth pursuing to preserve the human race. However, the alien invasion fleet also has limitations. They are leaving a dying planet and can carry only as much as they are able. Some new developments are possible but must be balanced against their survival over the length of the journey while still having the firepower to eliminate humankind and take over.

Couldn’t there be peace talks? Shouldn’t there be an intergalactic federation set up that mediates between worlds and star systems? Much of popular sci-fi rests on this principle, Star Trek being a prime example. But there’s the Fermi Paradox, and The Dark Forest considers one of its scenarios seriously. The long passage of time between now and Doomsday allow for the exploration of multiple strategies humankind might take, and as a reader you experience the roller-coaster of highs and lows as different options are considered or acted upon. Saying any more than this would be throwing in spoilers, so if any of the above sounds intriguing, you might enjoy The Dark Forest. I’m certainly intrigued enough after reading to proceed to the final book in the trilogy, Death’s End.