“I don’t know why you say goodbye, I say hello.”
The Beatles ‧ 1967
Why Liu Cixin’s Chilling Vision May Exaggerate the Dangers – in Space and on Earth
1. A Tale of Two Dark Forests
Liu Cixin’s award-winning trilogy Remembrance of Earth’s Past (commonly called The Three-Body Problem series) popularized the Dark Forest Hypothesis: in a universe where every civilization fears annihilation and resources appear scarce, the safest strategy is absolute silence – or a pre-emptive strike on anything that betrays its position.
Yet, just as children often overestimate the terrors of a literal dark forest, adults may be overestimating the hazards of its cosmic counterpart. Both fears rest on questionable assumptions about scarcity, detectability, and universal hostility.
2. How Dark Is the Cosmic Forest – Really?
2.1 Abundant Resources
• Asteroid mining makes most “resource wars” unnecessary.
– Example: NASA’s current Psyche mission targets a metal-rich asteroid whose contents have often been cited – though the estimate is highly speculative – as being worth about $100,000 quadrillion.
– Lower gravity and higher ore purity mean it is far easier to extract metals in space than to invade a habitable planet.

• Science-fiction authors anticipated this logic well before the 1970s, from Garrett P. Serviss (1898) to Isaac Asimov (1953) and Poul Anderson (1963-65).
2.2 Alternative Solutions to the Fermi Paradox
The silence we observe could stem from:
• the brevity of civilizations’ effective ‘radio window‘ (50-70 years);
• the Sanctuary Hypothesis (ETI nurture developing planets without revealing themselves);
• crewed or uncrewed craft-based exploration rather than radio beacons (compare UAP/UFO debate). These sightings challenge the premise of universal silence.
2.3 Humanity Has Already Broadcast
Between 1945 and 1961 alone, Earth detonated more than 2,000 nuclear devices. Each blast produced an electromagnetic pulse (EMP) strong enough to be detected light-years away. The most powerful explosion was ten billion times stronger than the Arecibo broadcast message and could have been received anywhere in the Milky Way, which may contain 300–500 million habitable planets. If an advanced civilization were listening, they’d see Earth suddenly erupting in artificial, high-energy flashes.

Additionally, humankind has been broadcasting TV and radio signals since the 1930s, and these signals can be received hundreds of light-years away.
In effect, we have already shouted our existence into the forest; worrying about a polite radio greeting now is like closing the barn door after the horse has bolted.
The Ostrich Problem: Silence Isn’t Safety
If ETIs detect our radio signature, broadcast or EMP, but hear no follow-up, they might assume:
- We’re hiding (suspicious).
- We’re unstable (dangerous).
- We’re ignorant (vulnerable).
3. Game-Theory Revisions: Three Big “What-Ifs”
Here are some of the big “what ifs” that challenge the whole “hide or attack” idea:
3.1 Mutually Assured Destruction (MAD) on a cosmic scale
If retaliation is credible – and especially if the cost of failure is extinction – first strikes lose their appeal, exactly as they did with Cold War nuclear strategy. Think about our own history with nuclear weapons. The concept of Mutually Assured Destruction (MAD) is a huge deterrent. What if that applies on a cosmic scale too? Let’s say there’s a certain chance of a successful attack. And, crucially, if an attack fails, the attacking civilization faces a really nasty consequence – let’s call it the disaster of retaliation. We’re talking about something far worse than just wasting resources.
Here’s how that changes the math for choosing to “Attack”:
If one civilization tries to hit another:
There’s a certain chance it pulls it off. The attacker survives, though it still pays the cost of the attack, while the other civilization is wiped out.
But, there’s also a chance the attack completely flops. In that nightmare scenario, the attacker is the one facing the disaster of retaliation (or even total annihilation if the other civilization hits back hard), and the target is still around and really angry.
So, when you consider whether to attack, you have to weigh these probabilities. If the chance of a successful attack is low, or if the disaster of retaliation is utterly catastrophic (like in MAD), then the appeal of attacking first plummets. It might even make more sense to just stay hidden, which totally undermines the “attack first” logic.

3.2 The Impossibility of Hiding

Sufficiently advanced telescopes detect radio signatures and other technosignatures whether or not we transmit on purpose. Admittedly, humankind has only transmitted purposefully for only a bit over 67 hours in its entire history. But this doesn’t reduce over a century of radio and TV signals that are already out there. Within this 130 light-year bubble (260 light-years across) there exist between 700-1,140 habitable worlds. If stealth is futile, the strategic game reduces to “communicate or attack,” and communication becomes the cheaper, more mature, safer option.
The Dark Forest idea hinges on the ability to stay hidden. But what if detection is inevitable? Imagine super-advanced telescopes that can spot signs of life without anyone broadcasting a thing. In that case, the “Hide” strategy basically becomes the same as “Broadcast” – you’re going to be found either way. The whole benefit of trying to hide just disappears.
If being detected while hiding is as bad as outright annihilation, then:
– If both civilizations hide → annihilation.
– If one hides and one broadcasts → annihilation.
– If one hides and one attacks → annihilation.
This scenario pretty much pulls “Hide” off the table as a viable survival strategy. It forces civilizations into a choice between broadcasting or attacking, since there’s no real hiding place left.
3.3 Civilizational Diversity
Assuming every species is paranoid and violent ignores the probability distribution of motives. If even a modest fraction are cooperative, expected-value calculations tilt toward cautious outreach rather than universal suppression.

Perhaps the biggest assumption of the Dark Forest is that every civilization out there is a paranoid, aggressive killer. But is that realistic? We can think about different “types” of players in our cosmic game. What if there’s a certain probability that a civilization is hostile, and also a probability that it’s cooperative?
Now, the overall benefit of broadcasting changes dramatically, depending on who you meet. It’s a blend of the risk of annihilation if you meet a hostile civilization, and the potential benefit of survival and cooperation if you meet a friendly one.
If the probability of encountering a cooperative civilization is high enough, and the benefits of cooperation are truly significant, then suddenly, broadcasting might actually be a better bet than attacking. It opens the door to the idea that some civilizations might actually try to say “hello” rather than “kaboom.”
So, while the Dark Forest is a chilling thought experiment, these added factors suggest the universe might be a bit more complex than just a cosmic shooting gallery.
4. Earth’s Own “Dark Forests”: Fear vs. Fact

U.S. National Parks – millions of annual visits into true wilderness – average roughly 0.11 deaths per 100,000 recreational visits. The leading causes are drownings (20.9%), car accidents (17.3%), medical events (12%), and suicides (12.4%), not wolf packs or bear maulings.
A global study of carnivore attacks from 1950 to 2019 documented 5,440 attacks, with about one in three being fatal. Likewise, tiger attacks in India average 34 deaths per year; direct wildlife fatalities in the United States hover around eight. Our imagination inflates the danger of forests much as it inflates the peril of first contact.

In the Star Trek movie “First Contact,” the Dark Forest of the human heart (causing a nuclear Armageddon) proved much more dangerous than the meeting with the Vulcan emissary.
5. Why Would ETIs Attack Us?
Possible motives beyond resources:
- First-strike paranoia (fear of future competition).
- Ideological conflict (ethics, expansionism).
- Scientific curiosity (studying emerging civilizations).
But if aliens wanted resources, they’d mine asteroids, not Earth. (Take that, Zecharia Sitchin – your ancient alien gold-mining slaves theory doesn’t hold up when space is full of purer, easier-to-extract metals.)
6. UAPs & the Pentagon’s Admission: Are They Already Here?
If Unidentified Anomalous Phenomena (UAPs) are extraterrestrial probes:
- They’ve seen our nukes, satellites, and wars.
- Silence may look like hostility.
- A controlled message (math, music, science) could be safer than ambiguity.

7. Synthesis: From Paranoia to Policy
- Accept the beacon we have already lit (Radio and TV bubble, nuclear tests) and
- Send cautious, non-threatening signals (math, art, science).
- Study apparent probes (UAPs/UFOs) with scientific rigor, but get out of the denial-loop.
- Prepare a diplomatic framework – a “UN for exocivilizations” – before we need it.
- Invest in asteroid-mining technology; abundance is the best antidote to resource anxiety.
The universe may contain dangers, but the data – from asteroid economics to wilderness safety statistics – suggests we routinely overrate them. Instead of cowering in silence, humanity should engage with the cosmos thoughtfully. We most do so armed with game-theoretic prudence, technological optimism, and a clear appreciation of how rarely the monsters in our dark forests turn out to be real.
Stop Whispering, Start Strategizing!
The Dark Forest Game Theory Equations (PDF)
References:
National Park Service. (n.d.). Deaths in National Parks. U.S. National Park Service. Retrieved June 14, 2025, from https://www.nps.gov/aboutus/mortality-data.htm
Skylis, M. B. (2024, February 27). Data Reveal How People Die in National Parks. Backpacker. Retrieved June 14, 2025, from https://www.backpacker.com/survival/deaths-in-national-parks/
Handwerk, B. (2023, January 31). What 70 Years of Data Says About Where Predators Kill Humans. Smithsonian Magazine. Retrieved June 14, 2025, from https://www.smithsonianmag.com/science-nature/where-lions-and-tigers-and-wolves-attack-and-kill-humans-180981539
Conover, M. R. (2019). Numbers of Human Fatalities, Injuries, and Illnesses in the United States Due to Wildlife. Human–Wildlife Interactions, 13(2), 12. Retrieved June 14, 2025, from https://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=1544&context=hwi
APPENDIX: THE THREE BODY PROBLEM in brief

Liu Cixin’s *Remembrance of Earth’s Past* trilogy, commonly known as “The Three-Body Problem” series, is a sweeping hard science fiction epic that explores humanity’s first contact with an alien civilization and the existential threats that follow.
1. The Three-Body Problem (三体):
humanity learns an invasion fleet will arrive in 450 years; physics itself is sabotaged by proton-sized “sophons.”
Initial Setup & The Cultural Revolution:
The story begins in China during the tumultuous Cultural Revolution, where astrophysicist Ye Wenjie witnesses the brutal death of her father. Disillusioned with humanity, she is later recruited to a secret military project called “Red Coast,” a deep-space listening station. There, she discovers a method to amplify radio signals using the sun and, in a moment of profound despair, broadcasts a message into space, essentially inviting alien intervention.
Present Day Mystery:
Decades later, in the early 21st century, a series of mysterious suicides among prominent scientists plagues the world. Detective Shi Qiang (Da Shi) investigates, collaborating with nanotechnologist Wang Miao. Wang becomes entangled with a mysterious online VR game called “Three Body,” which simulates a chaotic planet experiencing extreme climatic shifts due to the gravitational pull of three suns.
The Trisolarans Revealed:
Through the game and his investigation, Wang uncovers a vast conspiracy: the Earth-Trisolaris Organization (ETO), a secret society formed by humans who worship the Trisolarans and desire Earth’s destruction. The Trisolarans are the inhabitants of the chaotic “Three-Body” planet. Their civilization has been repeatedly destroyed by their unpredictable system, leading them to seek a new, stable home – Earth. They are on their way, but their fleet will take approximately 450 years to arrive.
Sophon Blockade:
To prevent humanity from developing technology capable of resisting their invasion, the Trisolarans deploy “sophons” – proton-sized supercomputers that unfold into higher dimensions, act as omnipresent spies, and subtly disrupt fundamental physics research on Earth, creating the illusion that science is failing. The first book ends with humanity aware of the impending invasion but hamstrung by the sophon blockade.
2. The Dark Forest (黑暗森林):
Luo Ji invents cosmic MAD – threatening to broadcast Trisolaris’s coordinates – and forces a temporary peace.
The Crisis Era and Wallfacers: With the Trisolaran invasion fleet on its way and sophons making all human communications transparent to the aliens, humanity enters the “Crisis Era.” To develop secret strategies, the United Nations designates four “Wallfacers” – individuals granted immense resources and autonomy to devise plans that remain entirely within their own minds, impenetrable by sophons.
Luo Ji and Cosmic Sociology:
Among the Wallfacers is the initially reluctant and cynical astrophysicist Luo Ji. Unlike the others, he doesn’t have a clear military or scientific background. He slowly develops the “Dark Forest Hypothesis” (based on insights from Ye Wenjie): the universe is a “dark forest” filled with advanced civilizations, each acting as a silent, paranoid hunter. Any civilization that reveals its location becomes a target for pre-emptive destruction, as there’s no way to guarantee another civilization’s intentions are benign, and rapid technological explosion makes any unknown a potential existential threat.
The Deterrence Era:
Luo Ji’s seemingly bizarre actions as a Wallfacer lead to his plan: he threatens to broadcast the coordinates of the Trisolaran home system to the entire galaxy, a suicidal act that would doom both Trisolaris and Earth (due to Earth’s proximity). This threat, known as “Dark Forest Deterrence,” forces the Trisolarans into an uneasy peace, as they realize Luo Ji can enact mutual annihilation. This ushers in the “Deterrence Era,” a fragile peace enforced by the constant threat of a “Swordholder” (Luo Ji) initiating the broadcast.
The Great Fleet Annihilation:
Humanity flourishes during this era, building powerful space fleets, believing they have achieved parity with the Trisolarans. However, when the first Trisolaran probe (“the Droplet”) finally arrives, it effortlessly annihilates Earth’s entire space armada, revealing the vast technological superiority of the Trisolarans and shattering humanity’s hubris.
3. Death’s End (死神永生):
deterrence fails, higher-dimensional weapons collapse the Solar System, and the protagonists ultimately sacrifice themselves so the universe can “bounce” and begin anew.
New Challenges and the Swordholder:
The Deterrence Era continues, but Luo Ji is aging, and a new “Swordholder” must be chosen. The burden falls upon Cheng Xin, a kind and compassionate aerospace engineer. Her appointment is a calculated move by the Trisolarans, who correctly predict her moral nature will prevent her from activating the deterrence in a crisis. When the Trisolarans test the deterrence by attacking Earth’s broadcast stations, Cheng Xin hesitates, allowing them to take control of Earth.
Humanity’s Flight and Cosmic Revelations:
A few human starships that had escaped the initial Droplet attack (including one that had gone rogue much earlier) manage to broadcast the Trisolaran coordinates, leading to the destruction of the Trisolaran home system by a higher-dimensional alien weapon. Earth, however, is then also targeted by a “Dark Forest” attack.
Dimensional Collapse and Universe’s End:
Humanity faces escalating cosmic threats, including:
Two-Dimensional Attacks:
The ultimate “Dark Forest” weapon, a “photoid,” collapses the Solar System into two dimensions, an irreversible process that kills almost all of humanity.
Light-Speed Travel:
Cheng Xin and a few others escape on a light-speed capable ship. They encounter the former “brain-only” ambassador, Yun Tianming, who sends cryptic fairy tales that contain vital information about higher-dimensional physics and the nature of the universe.
Micro-Universes and The Big Bounce:
The narrative expands to encompass the universe’s ultimate fate. It’s revealed that advanced civilizations, to survive cosmic catastrophes like dimensional collapse, create “mini-universes.” However, the proliferation of these mini-universes is draining mass from the main universe, preventing its “Big Bounce” (a theoretical cyclical collapse and rebirth).
The Final Choice:
Ultimately, Cheng Xin and a few companions, after millennia of wandering the cosmos and witnessing countless cosmic events and the end of the universe itself, are faced with a profound choice: contribute their own remaining mass to the main universe’s rebirth, effectively ceasing to exist, or remain in their isolated mini-universe. They choose to return their mass, hoping to contribute to the cycle of universal renewal.
The trilogy is renowned for its grand scale, complex scientific concepts, and unflinching exploration of humanity’s place in a vast, indifferent, and dangerous cosmos. It presents a grim, yet intellectually stimulating, vision of interstellar survival.