the three body problem, and what an interstellar war would really look like
A popular Chinese hard sci-fi novel imagines a coming war with an alien species and gets some things right in the process, and badly fumbles the others.
In the universe of the Three Body Problem, humanity is not alone in the cosmos and governments made plans not just to contact alien intelligence, but to compete to tell them their own story of Earth in a bid to secure cooperation from a civilization that’s a lot more advanced than our own. None have succeeded except China, but even that isn’t widely known to the Chinese because the scientist who made contact, Ye Wenjie, has kept it secret until some very bizarre stuff starts to happen, and scientists whose discoveries should propel us forward are exiting stage left after completely giving up on sciencing like it’s going out of style.
You see, when Ye discovers how to make contact with alien life, she was doing a very stupid thing and essentially using the Sun’s magnetic field to scream loudly into the universe and see who answers. The species that heard her call are the Trisolarians of Alpha Centauri, our nearest stellar neighbor, and the alien who heard this cry issues a dire warning. “Shut up or you’ll get invaded by our fleets because we’re desperate to get off our planet.”
Instead of heeding that warning and realizing that yeah, maybe the alien who grew up on said alien planet and knows their fellow aliens has a hint or two about what could happen next, and it’s probably a good idea to at least sleep on their warning and give it a hard thinky-think, Ye — whose psyche is scarred by the relentless persecutions of Mao’s Cultural Revolution that saw her father beaten to death in public and her sent to strip mine and deforest mountains in Inner Mongolia — decides to reply “eh, you can’t be worse than the CCP, come nuke us.”
And would you believe it? The Trisolarians said “on our way, kill you in 450 years.” Ye then goes on to team up with an entire cult of radical misanthropes who, frankly, think we all deserve to die because runaway late stage capitalism and greedy politicians are killing the planet, and made it their mission to give the alien armada the best possible chance at rocking Earth’s shit.
Naively, a faction within Ye’s cult now called the Earth-Trisolaris Organization, or ETO, believes that because the Trisolarians are more technologically advanced, they would also be more moral, empathetic, and egalitarian than humanity. Yet, as contact goes on in ways I don’t want to spoil, it turns out that the coming alien invader-saviors are basically butthole flavored buttholes, and openly call humans bugs that they need to squish with their continent-melting antimatter lasers.
So, yeah, Earth is not in a great spot because there’s a giant interstellar fleet hellbent on scouring the planet clean because their own home world is pretty awful. Instead of a stable orbit, it’s trapped careening between the three stars of Alpha Centauri. Since the interactions between those stars are so complex, every time they try to figure out how to predict when they can build a civilization or when they need to go into hiding, they’re guaranteed to fail and have to start over.
This is why they want our planet so badly. We’re a warm, stable paradise compared to their chaotic nightmare of a realm, and given what they were told about humanity by the ETO, in the minds of the Trisolarians, Earth is basically their home and we’re just a roach infestation they need to fumigate before settling into their new digs. But in their rush, they made a major mistake by actually launching a fleet to go conquer us.
henry haber was right, dammit!
This is one of a few major missteps in science the books makes, then quickly lurches to correct later on to avoid a plot hole. Before we get to all that, however, we need to take a bit of a detour and talk just a bit about Dark Forests, the Fermi Paradox, and the Kardashev Scale. We don’t have to dive deep into any of these because they are all highly speculative topics, but we need at least some idea of what they mean.
Basically, the Fermi Paradox was brought up by luminary physicist Enrico Fermi, who offhandedly observed that if Earth is a typical planet around a typical star, and using basic statistics we can estimate tens of thousands of intelligent alien civilizations all across the Milky Way, why don’t we hear them trying to reach out to us? Where are the extraterrestrial SETI projects?
Even more problematic is that certain alien species would’ve evolved millions, if not billions of years ago, and their technology would seem almost magical and godlike to us. Soviet astronomer Nikolay Kardashev developed a shorthand system to classify these alien societies into three types. The first, a Type I can harness every source of energy found on their planet. Type II can harness the energy of an entire star. And a Type III? They can manipulate an entire galaxy.
With all these civilizations putting out so much energy, we’d still detect them even if we weren’t trying. Type IIs would surround stars with energy collecting swarms and turn them strangely dark. Type IIIs would warp space and time with their engineering projects, creating bizarre gravitational lensing effects that would be obvious. And the effects of asteroid mining of a Type I would be evident in nearby systems. So, again, where is everyone?
One of the proposed solutions to this paradox is known as the Dark Forest. The best explanation of this idea I’ve seen in pop culture belongs to — believe it or not — the UFO No You Didn’t episode of Bob’s Burgers, delivered by precocious nerd Henry Haber in response to his classmates’ desire to use an old satellite dish to broadcast signals in search of alien intelligence as a science fair project.
In a way, you can think of Three Body Problem as taking this episode of Bob’s Burgers and making it extremely serious, then setting it in China, spanning from Mao’s reign of terror to today. But since Bob’s Burgers is a lighthearted show with the main message being that with family and friends, all problems can eventually be overcome, Henry is convinced to change his mind. In reality and the Three Body Problem version? He was absolutely right, what his classmates were doing was extremely dangerous, and his ploy to stop them was the responsible, logical things to do.
Despite entire religious cults being based on the idea that an alien civilization would be far more kind, moral, egalitarian, and inclusive than humanity, we have exactly zero evidence for this. If anything, they might be ready for war the moment they detect the existence of another civilization, happy to use their first strike advantage because a real interstellar attack would be over in one apocalyptic volley, and whoever launches first will use the least resources and have the best odds to win, probably also hoping not to attract too much attention themselves in the process.
how to win a war in one shot
With that established, let’s return to the Trisolarians and the gigantic, costly mistake they made by launching an invasion fleet at Earth. They even know they fucked up as they learn how quickly our science and technology is advancing, and even their most conservative projections show that after 450 years, their ships will be arriving into a slaughter by a humanity armed with space elevators, antimatter bombs, and massive warships brimming with lasers and kinetic kill vehicles, or KKVs.
“Okay, okay, I get it. Then if Earth wanted to retaliate, we’d just send a bunch of nukes to Alpha Centauri to teach those Tri-buttfaces a lesson?”
Not exactly. That would be like using our biggest and most powerful ICBMs to deliver a not particularly impressive firecracker. If you have the energy to send a weapon to another solar system at anywhere approaching a decent percentage of the speed of light, you have all the firepower you’ll ever need. Its kinetic energy alone would be far more devastating than all the nuclear weapons we have today — possibly on par with all the nuclear weapons we’ve ever built depending on the exact velocity — going off at the same instant in the same spot.
There are some other, interesting options out there but they require megastructures the size of gas giants, if not stars, but would do the job very well. The point is that a weapon fires a laser, or a solid slug, or a sharp rock at as close to the speed of light as physics will allow, then the element of surprise and kinetic energy does the rest. In an ideal scenario, you wipe out the entire target species and its planet with no one left to even figure out if to retaliate or at what to retaliate, much less how.
Knowing full well that humans probably already understand all this, the Trisolarians of the Three Body Problem use their cult of radical human misanthropes to pull us back into the dark ages, and launch a weapon made of pure technobabble to mess with our particle accelerators — which we’d need to make the antimatter to turn them into high speed subatomic particles and gamma rays in reality, but to stop us from studying the nature of atoms in the book — and warp up our view of the cosmos to spook Earth’s premiere scientists from doing more science, like a Scooby Doo villain trying to haunt a place he wants to steal for himself.
This weapons grade technobabble warhead is very difficult to explain not because it’s extremely elaborate, trying to hide entire supercomputers worth of electronics in the extra dimensions of a proton, but because it doesn’t make any sense. It’s all very high dimensional and quantum, like a sci-fi prison wallet, but also nonsensical because it’s a) not how computing works, b) extra dimensions are additional measurements which describe the coordinates and shape of an object, and c) pays absolutely zero respect for conservation of matter and energy.
Given the fact that this Trisolarian insurance policy is basically big science words that are arranged on a page in a way that sounds like a big science thing, I’m going to take the liberty of ignoring it when talking about a more realistic war between our species because I refuse to play Calvinball with physics and it’s not even a remote possibility.
A much more realistic version is a computer virus targeting particle accelerators and observatories spread by the ETO cult, something we’d know how to diagnose, excise, and then guard against to make all the particle accelerators make sense again, and to bring our cosmological observations back to a sensical baseline. Then we’d go kick Trisolarian posteriors — whatever those look like — with enough power to turn their planet into… well, extra Hell. Hell++ if you will.
But it wouldn’t be much fun if we didn’t go into detail of exactly how we’d do that, or imagine a fun little plot twist in which an alien species that may want to wipe us out has an honest to goodness warp drive, as do we. After all warp drives are allowed by the rules of general relativity, they’re just really, really difficult to create and maintain given our current understanding of quantum physics and its relationship with a more grandiose framework detailed by Einstein and Poincare.
war of the warp-capable worlds
Imagine, if you will, humanity roughly 30,000 years from now. Earth’s current sphere of influence expends across the Local Bubble, around a thousand light years across, with 20 million stars and an estimated quarter of a billion planets, along with as many moons. Anyone who could have waged war on humanity without warp travel now has to throw their battle plans out completely. A species capable of casually hopping from star to star has too many planets under its control and requires astonishing resources to wipe out in one attack.
Even several trillion relativistic warheads wouldn’t be enough to put down humanity for good. Plus there was now a risk of early detection and intercept technology being standard planetary defense measures. A sure victory in one volley turned into a near certainty of a vicious retaliation. But that retaliation wouldn’t come in the form of vast invasion fleets that could now arrive in months rather than centuries or millennia, not nearly enough time to prepare anything more than a basic Hail Mary defense.
Invasion fleets made little sense unless you were conducting a precision operation and either wanted to leave as much intact as possible, or conduct psychological warfare. If light years were a minor inconvenience to you, you were living mostly in space and had little necessity for planets other than places with the gravity and air pressure to build hubs, bases, and do specialized science and research. Your main source of materials and energy were the quadrillions of asteroids, swarms of solar collectors, and antimatter generators the size of small solar systems.
Enter the Advanced Kinetics URKKV Ragnarock. Capable of traveling 99.999998% of the speed of light through matter-antimatter annihilation, each warhead slammed into the target with 300 sextillion joules of energy, more than enough to move a mountain range out of its way on impact. But it would never make to the surface. The air friction created by the 315 kilogram slug of tungsten, titanium, and carbon trying to pierce the atmosphere faster than most high energy cosmic rays ignited fusion.
A fireball of brilliant blue created by the Cherenkov radiation of high energy particles traveling faster than ordinary light through the gasses in the planet’s air would expand until the ground underneath melted into glowing jelly while gamma rays incinerated continent sized areas. Just one Ragnarock was enough to cause a mass extinction. Five were enough to force life to restart from rocks deep under oceans and lava tubes. Humans sent a hundred in one volley. Any offending species and the biosphere from which it evolved ceased to exist a mere hour after the first impact.
But these new aliens were smart. They seemed to be close to a warp drive and very casually sent transport ships to distant worlds. The typical one shot interstellar war simply wouldn’t work here, but neither would fleets scouring hundreds of planets. Far too many resources and far too much risk. Those definitely existed and were used all the time, but they were reserved almost entirely for exploration and handling more… human affairs. And, of course, planetary defense, which was very much present on this world. Still, a message needed to be sent.
Switching modes, the probe locked in on the alien hub. Its siblings were taking point in eccentric orbits around the aliens’ colonies. Despite their diminutive size and dire lack of real armaments, these devices were known as planet killers. Not because they did any damage, of course. Because they provided the final homing beacon for what did. A million Ragnarocks were on their way, but these ones were… different. Rather than URKKVs, command selected the WKKV variants. Just like all the stealthy, sleek ships that deployed the planet killers, these missiles were warp capable. Well, sort of. Their warp capability was broken. On purpose.
A typical warp ship used electromagnetic fields to collect the insane radiation created at the boundary of a warp bubble as its bow shock collided with countless particles just minding their own business in the vacuum of space. This intense energy would be funneled behind the ship, further distorting the fabric of space-time and accelerating the craft to seemingly impossible speeds, like a sort of superluminal Bussard ramjet. These missiles, however, didn’t funnel nearly enough of the radioactive debris which was now carried with them.
Their arrival was announced with a brilliant white light smeared around the planet. The equivalent of a supernova’s shockwave slammed into the alien world from nearly all directions, as the sea of particles once stuck to the warp bubble kept going by sheer inertia, turning into light, heat, and ionizing radiation. Orbital defenses were instantly vaporized or rendered inoperable. A moment later, kinetic warheads traveling at 99% of the speed of light entered the irradiated atmosphere.
Blinding blue fireballs erupted across all hemispheres, followed by vast spiderwebs of shockwaves, colliding and amplifying as they raced to the other side of the planet. For the aliens who called this now battered, irradiated world under a quickly spreading blanket of soot home, the entire sequence of events lasted less than a minute. They had been going about their day or sleeping during their night, a bright flash in the sky startled them, seconds later, deafening roars drowned out everything, and a few moments after that, they no longer existed.
speak very softly and carry a big rkkv
So, today we learned that our parents and Teddy Roosevelt were right. We should not talk to strangers who emerge from the shadows, grinning wide and pointing to a rusty, windowless van, and if we do speak to someone, we should do it softly while carrying something scary just in case things get a bit too tense. Ideally something capable of delivering a blow similar to the one that (probably, we think) doomed the dinosaurs at the top speed allowed by the laws of reality. A few hundred times. In a row.
Before you get too worried, the odds that a world-ending relativistic weapon from an alien solar system is headed our way are literally astronomical. Our broadcasts past a 100 light year radius are so degraded and garbled, they’re totally useless to find our planet. Within those 100 light years, each signal would be highly variable and require a lot of dedication to decipher as something worth an alien civilization’s time, assuming they even use radio waves. Plus, to detect our planet and its habitability would require looking directly at it and having the same biochemical definition of life.
It’s extremely unlikely that anyone found us. Yet. At the same time, we’re also not fully safe and it would be very wise to prepare for something nasty to come our way. All we need is to learn how to make industrial quantities of antimatter, mine asteroids, maybe build a Dyson swarm, and figure out how to adapt ourselves and expand beyond our home world, then keep going further. In a few millennia, instead of just being sitting ducks, we could be a force to be reckoned with while drastically improving our quality of life in the process.
Maybe instead of our leaders spending their days vomiting rage at the modern world like vampires hiss at a garlic necklace, and busying themselves with odd obsessions like whether boys and girls are allowed to kiss each other, or who can wear skirts vs. who can wear pants, or how those who give them money can keep draining the Earth to shove more crap we don’t need down our throats so random green line go brrr, it may just behoove them to actually consider the future and lead us, rather than keep calling themselves world leaders while limiting their duties to the social equivalent of creepy, busybody bathroom monitors and Peeping Toms?
I mean, if they can’t figure out how to make quadrillions turning this solar system into an alien-proof fortress just in case some big, ugly creatures whose poetry skills rank as the third worst in the universe want to build a hyperspace bypass right through Earth, they should really abdicate their positions and find something a little more their speed — perhaps historical reenactments of plague outbreaks, witch trials, or playing The Sims — while the rest of us build a real future society.