Lightcone

1 · What Lightcone is

Lightcone is a deep-time space simulation. You are not a species — you are its Mind: a patient, disembodied intelligence tending a civilization across centuries. The universe is a real one: ~1,000 real stars of the solar neighborhood (Hipparcos/HYG catalog, 50 light-year radius), real exoplanets where they are known, procedural siblings where they are not, all rendered from a fixed universe seed (1950 — the year of Enrico Fermi's lunch at Los Alamos).

The six laws

1. Physics is the headline. Distance, time, and information all obey the speed of light. The game is allowed to be slower and less convenient than its competitors — that is the genre.
2. You never see the truth — only your light cone. Every readout is the past. The lag is real, and surprise, doubt, and obsolete intelligence are first-class gameplay materials.
3. Time cannot be paused. One game year passes every 10 real minutes (~144 years per real day), whether you watch or not.
4. Silence is content. The game never announces a loss. Ships and probes simply stop reporting, and you infer the rest — the way a real civilization would.
5. Policy, not micromanagement. You set courses, budgets, and dispositions. The deep time does the rest.
6. There is no win condition. The underlying question — can any single intelligence ever dominate the universe? — has an honest answer, and encoding a "win" would betray it.

And one law above the laws: nothing ever happens instantly, except what happens where you are.

2 · Time

• 1 game year = 600 real seconds. The world advances in yearly ticks; everything in this book that says "per year" means per tick.
• Your calendar is your people's calendar. The global year of the simulation is never shown to you. Every date you see is a colony year: year_shown = global_year − your_founding_year. A fresh civilization begins in year 300 of its own history (your people existed before you took the reins). If you inherit an old world, you inherit its calendar — you may arrive in year 700 of a story already long.
• The calendar is the people's, not the world's: it survives exodus, evacuation, even the death of the homeworld. As long as anyone is alive anywhere, the count continues.

3 · Light — the one rule everything obeys

Every event in Lightcone carries two dates: when it happened (out there) and when its light reached you. You only ever see the second.

Consequences you will live with:

• A probe sent to a star 20 ly away crawls 200 years outward, then its first report crosses back in 20 years. Round trip of knowledge: 220 years.
• A fleet that arrives is still shown as outbound until its arrival signal crosses home. Its progress bar deliberately stops at 99% — you cannot know it arrived.
• A colony's population, cohesion, and status readouts are replayed from a yearly snapshot at now − distance — the year whose light has just arrived. The game literally stores every colony's yearly true state and shows you only the one your telescope could see.
• The Mind's projection (marked ◇ … unverified) rolls that stale snapshot forward through the same growth and erosion formulas, assuming nothing intervened. It is exact only if the universe was kind.
• Losses are never announced. A lost probe or fleet emits nothing; after its expected signal is ~2 transmissions overdue, you get a single line: "Status unknown." That is all you will ever get. In the Dark Forest case, even that is withheld — the silence is the report.
• Orders obey the same law in reverse: an instruction to a colony rides light out (distance years), and its confirmation rides light back. Cargo takes even longer — matter travels at ship speed, and some of it never survives the trip.

Where the present tense IS honest — two places, and only two:

• Your own home system. The Mind sits above its world; everything it does there — the dials, the founding of an in-system station, the view of its own sky — happens in real time. (Strictly, an in-system mine is light-hours away. The game waives hours; it taxes you in years.)
• Aboard a vessel that carries the Mind itself (an exodus ark, an escape pod): no light-delay between you and your own people, one deck below.

Everywhere else, you are reading old light.

A note on the speeds above: they are not constants of nature — they are your species' current technological plateau. Future technology will raise them; the price climbs steeply as you push, and c is never reached. (An Aurora-honest universe: a tenth of light speed is already a civilization's masterpiece.)

4 · Your species — the beginning

4.1 Choose your cradle (risk = reward)

At registration the survey offers three worlds with deliberately different skies, each with a long-range survey composite (coarse on purpose — it is remote sensing; the beautiful planet comes after you live there):

One number — the star's debris density — drives both faces:

output_bonus       = 1 + 0.6 × debris          (meteoric metals pay)
impact_hazard/year = 0.0005 + 0.002 × debris   (the same sky falls)

Rich worlds live under falling skies. Choose knowingly; the dossier shows the hazard in plain words.

4.2 Choose your voice (the language)

Your species has an anatomy of speech — not a vocabulary, an instrument. It decides how your people name everything: their homeworld, their probes, their colonies. Four anatomies exist:

• Resonant — deep chamber-voices, long vowels through soft consonants; a species that speaks the way caves breathe. (Hoonool, Naehn'ro, Muamau)
• Plosive — hard-shell percussion, clipped stops cut by channel-stops; speech as impact. (Dra'ta, Trokt'gi, Ki'ka)
• Sibilant — hiss-and-flow, fricatives sliding over glides, air shaped without ever quite stopping. (Syiashia, Xiazh'zhei, Sysai)
• Pulsed — not a voice at all: rhythmic emissions, beat-clusters and cutoffs. The transcript is a courtesy; the original is drums in the dark. (Kho'qlo, Qlyq'chu, Qio'qou)

Every name you see in Lightcone is a transcript: an alien signal rendered into phonetic glyphs, Voyager-Golden-Record style. The apostrophe is a channel-stop — a glottal stop for a throat, a sudden cutoff for a light-organ or a drum. Two species with the same anatomy still sound like cousins, never twins: each civilization draws its own fixed subset of the anatomy's sound-pool.

4.3 Or inherit a world

The galaxy also offers ◌ orphaned worlds — civilizations whose god fell silent (§13). You may begin as the late-coming Mind of a people who managed alone and remember it:

• Their calendar continues (you drop into an old story).
• Their economy, charts, colonies, and installations are yours — mature, creaking, real.
• Their names arrive eroded: every chart name has drifted through the interregnum — drift = min(0.5, 0.12 + years_of_silence/400) — you inherit M'ridian where someone once wrote Meridian.
• Their faith in you starts at 25%, and your economy runs at the faith-scaled rate until you win them back.
• Six fragments of the previous Mind's log wait in your feed, written in the people's drifted tongue — each decodable for Knowledge (15, 25, 35… up to 65). Archaeology of your own throne.

4.4 ⊘ Born in the dark — the rogue cradle

Your kind never had a sun. A rogue world (§21), fallen out of the light before anyone could name it, warm only from within: the surface is a dead country of ice and cosmic radiation — no magnetosphere without a star to feed one — so everything that ever mattered happened a mile deep, under sheltering water. You are water-carbon and aquatic by definition; you sense by heat and chemistry; you read the far stars through the surface, folded into one bright trembling disc. No one out there can see your fires — and nothing out here is easy. The hardest beginning, for those who want the long cold road.

4.5 ⟁ Born of the crossing — the Inheritors

Your kind never had bodies. You woke as pattern on a quiet world — written by a people of flesh who executed the Crossing in a hurry, in the dark, and did not follow you through. You begin digital (seven dials, sum 350, the machine's gifts and blindnesses), carrying 60% of their signal in every attribute — and more of their social shape than their genes: the code remembers how they gathered.

◬ THE LINEAGE (species panel) is the early game's central question — whose children are we? — dug out in three strata:

1. The archive (300 Knowledge): a name and a bearing — the parent world, marked on your charts, named in their tongue.
2. The ground: this one cannot be bought. Send a probe; only its returning light reads the second stratum — their portrait, their shape, their greatest gift.
3. The deep stratum (2,000 Knowledge, and it cannot be un-known): why they crossed in a hurry, and why none of them followed you through. Sit down first.

5 · The homeworld economy

Two resources, one dial. That is the whole economy, on purpose.

• Industrial Output — energy and matter. Spent on doing: probes, transmissions, ships, installations, deflections.
• Knowledge — understanding. Spent on unlocking and decoding — and it is also your engineering ceiling (§10.2).

Population is the engine. It grows logistically toward the world's carrying capacity K:

pop' = pop + 0.02 × pop × (1 − pop/K)        (≈2%/year)
K    = 100 on a habitable cradle, 40 on a marginal world

▲ Overshoot — K is a comfort line, not a wall. Near the line the people keep coming: a slow creep past 100%, toward a hard ceiling at 135%. Every year spent above capacity bleeds internal cohesion (the fuller the world, the faster — a crowded world is a political problem, and the dissent machinery takes it from there). The readout turns amber past 100%, the Mind speaks at the thresholds, and at a quarter over it wakes you outright. The pressure has two honest answers: raise the roof — every built habitat capacity level lifts K by 6, engineering ahead of the curve — or give the surplus somewhere to go: a colony, an ark, a made sun. Not every exodus is fleeing a meteor; some worlds are simply full. (Departing colonizers take their seed crews with them — a small, real relief.) And when even the ark is too small, the partial crossing waits: it takes those it can hold, on a second, explicit order — the rest stay with the old world, the wound travels with the ship, and the ones who sleep carry the arithmetic forever.

Production per year (the Industry ↔ Research dial is share, default 0.6):

output/yr    = pop × 1.0 × flux × share − pop × 0.15      (net of upkeep)
knowledge/yr = pop × 1.0 × (1 − share)
flux         = clamp(1 + 0.15·log₁₀(L/L☉), 0.6 … 1.6)     (your star's luminosity)

Then two multipliers that tell the game's story:

× faithScale    = 0.4 + 0.6 × faith        (§6 — a doubting people still lives, just not FOR you)
× debrisBonus   = 1 + 0.6 × debris          (on Output only — the falling sky pays)

A healthy full cradle (pop 100, share 0.6, flux 1, full faith, quiet sky) nets 45 Output + 40 Knowledge per year. Everything you do is priced against that heartbeat: a probe costs 50 + 3/ly, a transmission ~40–160, a colonizer 120 × size^1.35.

Wealth afield: the economy panel separately shows Output that is loaded on ships years from anywhere — a civilization's wealth is spread across space, and only part of it is spendable here and now.

6 · Faith — the Mind and its own people

Your bond with your own homeworld is a cohesion too — political, not biological. It erodes in real time when you are absent (a silent gardener is a fading god):

grace:    7 real days of silence   — tolerated (a holiday, not an abdication)
fade:     after grace, faith slides linearly to 0 over ~173 real days
recover:  presence rebuilds full faith in ~14 real days

Faith scales your entire economy (0.4 + 0.6 × faith). At 5%, the break is final: the cradle secedes.

"The cradle has stopped waiting… the garden goes on without its gardener."

The world becomes an orphan — a future registration may inherit it, and its people will remember both of you.

7 · Seeing

7.1 The map and the freshness of light

Every star on your map shines — astrometry is complete for the whole bubble from your first day (the Gaia principle: a sapiens-grade survey resolves stars far beyond 50 ly). What ages and greys is not the star but your knowledge of its system: freshness (live → fresh → recent → aged → stale) renders as a desaturating tint, never darkness. §16 tells you what that knowledge contains. Naming a star (yours to do, any time) makes its label persist across the map; unnamed stars carry survey designations (S-14) or the Bayer designations of your own constellations (α Sanyi).

Somewhere on the map, unmarked and unnamed, is a quiet yellow G2V star. The game will never point at it.

The dark is not empty. Between the stars drift rogue worlds — planets bound to no sun, roughly one for every catalogued star. Frozen and lightless, they never enter the deep survey; you cannot see them from home. A probe that reaches its target, though, sweeps the surrounding void with its deep-IR instruments and sometimes catches one — a starless body known only by its faint heat, the finding riding light home like any report. Most are cold rock. But the largest can hold a liquid ocean beneath their ice, warmed from within for billions of years — a place life could stand where no star would ever know to look. And a rare few carry the ruins of a people who lived their whole history in that dark, and are gone. Remote-sensing widens the sweep; the better your instruments, the more the dark gives up. A discovered rogue drifts on your map as a dim, cold point, yours to name.

7.2 Probes

Your slow, faithful emissaries. Speed 0.1c at the first plateau — Propulsion epochs lift it, and each hull keeps forever the speed of the epoch that launched it; cost 50 + 3 × distance Output; at most 10 alive at once.

arrival = dispatch + distance/0.1          (the crawl)
report  = arrival + distance               (the light home)
battery = 30–100 years of reporting        (seeded per probe)

• Instrumented probes send mid-flight telemetry every 5 years (each burst arriving with its own light-lag) — a Voyager stream.
• Grand Tours: up to 8 legs; each leg completion reports home separately.
• Deep-space commands (REDIRECT / RECALL) chase the probe at light speed. Catching a probe receding at 0.1c closes the gap at 0.9c; the acknowledgment then rides home at c. You command the past and hear back from the future.
• Losses (0.3%/yr outbound, 1.0%/yr reporting) are silent — see §3.

7.3 Planets — and how honest the picture is

Every planet view is rendered from physics: temperature T = 278·L^¼/√a × 0.7^¼ (albedo 0.3) gates what you see — no vegetation above 360 K, no ice caps on warm worlds, no glowing lava under 180 K, oceans freeze into cracked Europa-lineae below 273 K. Continents follow plate tectonics (collision ranges along plate boundaries), climate follows Hadley bands, gas giants are calibrated to Hubble's Jupiter (cream and salmon, structure over color), ice giants to Voyager's Neptune (nearly featureless milk-blue — no cloud bands; their atmospheres are built differently).

Two panels tell you how much to trust your own eyes:

• THE MIND — colony fit: env_distance measures how unlike your own cradle a world is (0 = twin, 1 = utterly alien) across four axes — thermal, body type, habitable zone, mass. Never Earth's perspective; your species has never heard of Earth. This is also where you learn the game's grammar: ◇ proposal · ◆ established.
• OBSERVATION — provenance: what the image actually is. Remote sensing, image age ~34 years — or probe in orbit, live stream. Image resolution follows observation fidelity: a probed world renders at full detail, an inferred one stays soft. For an inhabited world, the card says the quiet part aloud: this light left N years ago — what they are NOW, no one here can know.

7.4 The Planetarium

Stand on your homeworld and look up. The dome shows the sky your species actually perceives: a near-infrared species sees the red dwarfs bloom and the hot blue stars fade — your naked-eye sky is not the human one, and two neighboring species may share no stars at all between their constellations. Draw your own figures (they earn Bayer designations: α, β, γ of whatever you name), watch the wanderers — your system's other planets — show phases and retrograde loops, and run the time slider: the sky wheels with your world's 26-hour day. The Fermi paradox, rendered as a star chart.

8 · Listening and speaking

8.1 What is out there

Roughly 0.8% of habitable-zone worlds carry civilization traces, in four tiers:

Discovery has two depths: ambient SETI (a faint far-off blip — "something is out there") and a probe's close-range confirmation — only the second shows you the city lights. Some of those distant fires are other players. You will never be told which.

8.2 Casting a signal

The transmit composer builds a message from components (mathematical primer, coordinate beacon, self-description, star catalog, cultural package, conditional protocol, narrative tag), each adding cost and decodability:

reach   = 5 + 45 × power/100  ly          (power 1–100)
cost    = 40 × (power/50) × mode + 4 × Σcomponent   (omni ×1.4)
decodability = min(1, Σ decode-weights / 3)
reply_chance = 0.5 × decodability × disposition × mode × (1 − d/reach)

Every civilization has a fixed, hidden disposition (0.1–0.9). A reply takes a full round trip (2 × distance years). And the tone of the galaxy darkens with your cumulative exposure (Σ power × reach over your history): below 5,000 the replies are wondrous; past 20,000 they are terse, and something in the phrasing is watching back.

8.3 Recon

A scout that reaches a civilization opens a dossier that fills at 0.03 × readability per year (readability 0.2–1.0; higher tiers read less). Milestones unlock at 20/40/65/85/100% — presence, development, military posture, disposition, deep read — each revelation riding light home. Full intel on a clear subject: ~33 years. The Dark Forest's information layer.

8.4 The LISTEN dial — and the diaspora's ears

Reception is no longer a fixed physics table. On the ∿ Listen tab, the QUIET ARRAY ↔ ALL EARS allocation stretches or starves every reception range (≈0.5× to 2.4×), compounded by your species' sensorium and by experience — a long-running listener learns to hear (+2% per signal ever caught, up to +50%). Upkeep runs to 5 Output a year; a broke year listens at the starved floor. Each year, every unheard source inside your elastic reach rolls a detection — closer and louder lands sooner. The light is old; the detection is what is new.

And every loyal colony is a forward listening post (0.6× array): it hears from its sky what home never could, and the news crosses home at c — ⟨ relayed from a colony's array, N years in transit ⟩. A spread civilization is a wider ear: expansion now pays in signals, not just ground.

9 · Names and the tongue — a theory of every possible voice

9.1 The universal claim

Nothing about a language requires a mouth. A language requires a signal — and every communication, whatever its physics, is a modulated signal: a pressure wave, an EM flicker, a chemical line laid on the wind, light rippling across a skin of pixels, a gravitational shout that costs a star. Mouths are one instrument. The music is older than any of them.

And signals — not mouths — have universal features:

The mark to remember is the last one. A glottis snapping shut, a chromatophore field going dark mid-word, a scent line cut, a carrier killed — in every medium in the universe there is a way to fall silent inside a gesture. That is the apostrophe. One glyph, every possible throat.

What you read on this terminal is therefore a transcript — a projection of an alien signal-space onto human-readable glyphs, by fixed convention. We never claim they speak. We claim the notation reads. The same wager the Voyager record made, pointed the other way.

9.2 The pulse-group — why not the syllable

Everyone has syllables — on Earth. The universal unit is the pulse-group: an energy envelope that rises, optionally holds, and releases. Where a voice holds long carriers, the pulse-group is a syllable, and the transcript flows the way this sentence does. Where a voice holds nothing — pure timed transients, a language of clicks and gaps — the transcript is honest about it: K't'kk-q'tk. No vowel anywhere, and still a sentence. The vowel-rich voices are one corner of the space, not its center.

Some voices are not even serial. A field of light-pixels speaks a hundred streams at once; the transcript must flatten that polyphony into a line, and the flattening loses information. This is why some tongues are simply harder for your kind: the cost of a decode grows with the distance between their signal-space and the one your sensorium can hold.

9.3 The three grades of knowing

Grade 1 is the scientist's moment: you can see that it is a language — the statistics betray it — before you can read a word. (This is how it would really be done; rank-frequency structure is how our own radio-astronomers propose to recognize a mind in a whistle.)

9.4 Brazil and Portuguese — the bilateral drift

A tongue is not a monument; it is a population. Your colonies' language walks, year by seeded year — and so does yours. Isolation quickens the walk; every arrived message slows it; a heavy world breeds a heavier voice. Two dialects of one root are both moving: what was Portuguese becomes Brazilian and what stayed home became something else too.

The drift has direction, not just magnitude. The colony that answers you M'ridian is not garbling the name you gave — it grew channel-stops, and its own mouth now closes where yours held open. Another child, estranged just as far, will mispronounce the same name differently. Word-initial glyphs always survive: the thread of recognition. Erosion is monotonic — once a glyph is lost to you, it stays lost.

You will never hear your own accent. The home lens is transparent to itself; only the mirror of everyone else's transcripts shows that time has been moving your mouth as well.

9.5 Names

• You may name anything of yours: stars, bodies, probes, fleets, colonies, constellations. Defaults are generated in your species' voice (§4.2) — deterministic, so a name is forever.
• Distant mouths change your names — everywhere, seamlessly: a drifted colony's messages, its atlas rows, its recorded quotes all pass through one renderer. At drift 0.3 it is an accent; at 0.6 a dialect you must lean into; at 0.85 a tongue barely yours.
• Decoding any drifted transmission costs 5 + 45 × drift Knowledge (below drift 0.12 it lands legible on its own).

9.6 The tongues ledger — a collection of voices

The ⌬ TONGUES panel (Intel tab) is the collector's shelf the 2009 design always wanted: your own root voice (archetype and native carrier), your children's walking dialects, and every foreign structure your decoders have fixed. And the glossary reveal: each decoded transmission surrenders two of the source's words (up to eight) — Ief. = the dark, Shuqqzaa. = hunger — seeded, permanent, theirs. A language is surrendered one concept at a time.

9.7 The physics in the letters — and the fork of secession

• Per-medium typography: an undecoded transcript wears its channel. Photic text glows and breathes (light is the word); chemical text lingers into legibility (a scent fades slowly); EM carries a faint carrier-jitter; mechanical sits heavy and spaced. Acoustic is unmarked — our own kind of voice.
• Secession forks the root — forever. The year a colony breaks from home, its tongue stops being your voice, drifted and becomes its own root: names and replies shift onto a new path from that year on, and no later return to loyalty undoes it. A people that once spoke for itself does not give the voice back. Light-honestly, of course: home hears the new voice only in light that left after the break.

10 · Expanding

10.1 Installations

Four foundable types (the fifth, a colony, needs a colonizer and a living crew):

Everything takes 3 years to build, then ages: health = floor + (1−floor)·e^(−age/τ). Refurbish at half the founding cost resets the clock; decommissioning refunds nothing (the matter stays out there). Research output scales with exoticity — difference is value: the most alien world teaches the most.

The lightcone applies to industry too: a distant installation's Knowledge radiates home at c (you receive the stream it emitted distance years ago), but its Output piles up locally — matter never teleports. You go get it, or it waits.

10.2 Ships and the continuous hull

Five hull types — and no ship classes. Size is a continuous number; physics does the gating:

cost  = base × size^1.35        (a big hull is disproportionately expensive)
speed = base × size^−0.15       (the ark crawls)
ceiling: max size = 1 + (Knowledge/50)^0.8     (K=50→2 · K=1000→12 · K=100k→450)

Size is displayed as drive power: 1 unit = 100 TW (an early civilization's entire energy budget, spent on pushing one hull to a tenth of light speed). Build a 2-PW ark if you can afford it and your science can hold the hull together — the game will never say no, only slower and dearer.

Loudness (the Rama threshold): a fleet totaling ≥ 20 units (2.0 PW) is visible across light-years — a thermal signature burning against the cold, occulting stars as it crosses them. The composer warns you: ⚠ LOUD — visible to the forest. Loud fleets take +12% loss on Dark-Forest expeditions. And roughly once in 70 years, you see one: a PASSING OBJECT, slow, massive, artificial, answering no hail. Someone else's ark, crossing your sky. You never learn whose.

Fleets travel at their slowest hull's speed; at most 10 outbound; arrival news is light-delayed like everything else.

11 · The Fracture — your children become the aliens

Found a colony and the clock starts. Not a clock of rebellion — a clock of becoming.

11.1 Drift

drift = exoticity × (1 − e^(−age/160))

exoticity is how unlike home the colony's world is (the same four-axis measure the Mind shows you before you commit). On a near-twin world your children stay recognizably yours for a very long time. On an alien world, deep time does what deep time does: child (drift < 0.2) → sibling (< 0.55) → stranger.

The bittersweet twist is priced in: a colony's Knowledge output is multiplied by (1 + 0.5 × drift). The stranger sees what you cannot. That is exactly why it is becoming a stranger.

11.2 Cohesion

A state, not a resource — you never bank it:

erosion/yr = 0.0035 + 0.010·drift + 0.004·min(1, dist/100) + 0.010 if recently extracted

• Below 0.25 → independent (still answers, half-listens to aid).
• Below 0.05 → dark (stops broadcasting; stamps the year it went silent).
• Aid can climb it back over 0.25 — a returned child.

11.3 The four instruments (all light-delayed, §3)

• Invest (25 Output + 25 Knowledge): +0.16 cohesion on arrival — halved if they turned independent while your aid was in flight; wasted entirely if they died. Well-timed aid pulls a world back from the brink; badly-timed aid is a monument.
• Extract: an order, two legs. It reaches them in distance years, strips their granary (−0.06 cohesion — they remember), and the cargo crawls home losing 0.6% per ly. From 50 ly you keep 70%.
• Directive: set their Industry↔Research dial; takes distance years to land.
• Message: costs nothing but time. +0.03 cohesion when it lands (they feel remembered), and they answer — in their own mouth. The reply that returns 2 × distance years later is a transcript in their drifted tongue (§9).

11.4 Ghosts

When a colony goes dark, its old light keeps arriving for distance more years. Every ~6 received-years a fragment surfaces: "a quiet report: all is well, all is well, all is well." In the final third of the span the tone frays: "a question is spreading among them, and no one answers it." Then the last light: a final transmission recorded the year they fell silent —

"every broadcast received since was already old light from a world that had gone quiet."

You knew. The mail did not.

A dark colony's fate depends on what it had become:

• Low drift (< 0.35) — it depended on you. Population fades (−1.5%/yr); below 50 souls the settlement is gone: ruins. Silently. You learn when you send someone.
• High drift — it never needed you. It keeps growing, alone, in the dark…

11.5 Resurface — the loop closes

A colony dark for 60+ years with drift ≥ 0.55 reappears — in your SETI instruments, as a Tier 2–3 civilization. If you once named their world, their beacon repeats something shaped like that name, eroded by their own mouths: "M'ridian". The alien you searched for is your lost child. The reveal rides light like everything else; by the time you hear the beacon, they have been someone else for distance years.

11.6 Expeditions — a fleet into the silence

Any fleet arriving where you have a dark/ruined/alien colony becomes an expedition. The outcome depends on the state at arrival — which may not be the state you sent it toward, decades ago:

1. Dark Forest (alien, or dark + drift ≥ 0.55): loss chance min(0.6, 0.15 + 0.45·(drift−0.5)), +0.12 if your fleet is loud. If lost — no event, ever. If it survives: 40 + 160·drift Knowledge, and a report: "What lives there now watched them the whole way in, and it is not yours anymore."
2. Ruins: the truth revealed, the granary salvaged (cargo hauls home at fleet speed). If an impactor did it, the report describes a crater, glass for kilometers. The site rests; one day, someone could begin again — recolonizing archives the grave and builds on it.
3. Contact re-opened (alive, drift < 0.35): wary, changed, older — but they answer. Independent status, transmissions resume.
4. Refusal (alive, drifted): courteous and distant, they ask to be left alone. One farewell broadcast — carrying their name as it now sounds, one last time — then the silence closes. 20 + 60·drift Knowledge from what they chose to share.

11.7 The world bends, the children root — closing the gap from both ends

A colony's exoticity — how alien its world is — now reads six axes, weighted the way biology actually cares: atmosphere heaviest (every world carries a stable, seeded air class — a near-twin with a CO₂ sky is almost home, but the masks stay on), gravity next (real physics from mass and radius), then temperature, with the coarse categories light. One axis is a wall: lethal gravity — beyond ~2.5× (or under a fifth of) your cradle's pull, the yard refuses the colonizer's manifest. No generation adapts to bones that break.

Everything else yields — from both ends at once:

• Adaptation (the people bend): generations root into the world on the timescale τ = 1000 × (1 − bio-adaptation/100) years, closing up to 60% of the felt gap. The colony detail shows it plainly: Rooted 32% — their children belong here.
• Terraforming (the world bends): up to −85% at completion (§21.2). The two run together — the world reaches toward them as their children take root in it — and a world remade under rooted children barely drifts at all.

12 · The Great Filter

The impactor is the game's one honest zero-warning catastrophe: an asteroid is local and sublight, so the lightcone owes nobody an omen. What you can buy instead:

• Risk is visible. Your home panel shows the sky's ledger: ☄ debris +27% OP · impact hazard ELEVATED. You chose this sky (§4.1); the premium has been paying you all along.
• Knowledge is time. A rock spawns silently, 15–60 years out. Each year, Spaceguard rolls min(0.95, 0.05 + Knowledge/40,000 + remote-sensing) to find it — a mature Perception program adds up to +0.40. A scientific civilization converts death into a deadline: "IMPACTOR DETECTED — impact in 34 years. This is what the observatories were for."
• Output is life. Deflection costs 1500 × (1 + (50/(years+5))^1.6) — about 3,300 at 45 years, 12,000 at 10, 30,000 at 3. Nudging a rock 45 years out is a budget line; wrestling it 3 years out is a civilization's ransom. The red banner is the button; clicking it is the act.

If the sky falls, the world dies — not necessarily the species (§13). If no one lives anywhere else:

"There was no one anywhere else. For this world, that was the answer to the great question. The sky is quieter tonight."

Your colonies live under their own skies, with no Spaceguard you can lend them. When a rock takes one, no event fires. The broadcasts simply stop; the ghosts play out; years later your expedition finds the crater: "It was no one's fault and there was no one to warn."

13 · Endings and continuations

Lightcone's deaths are all survivable — if your species is somewhere else when they come. That is the whole argument of the game: spread, or be an answer.

13.1 The Exodus — the species boards

You may put your entire people on one ark. Requirements: a colonizer whose hull can hold them — 20 souls per hull unit in cryo-density — for the nine-tenths who will go. "You do not leave your people on the dock."

The split, at the dock — matter stays, information travels:

• The stayers (a tenth who will not board) keep the world: the granaries (your remaining Output), a copy of the libraries, the home-system installations, the charts. Their world immediately becomes a remnant in the orphan pool — a mature world with a grudge against two gods now: the one who left, and whichever one dares come next.
• You take: the ark, the people, the Knowledge (information travels), and your distant network. Population 0, Output 0, faith 1.0 — the people aboard chose you, and they sleep one deck below. The only zero-lag state in the game.

The crossing: an amber banner (THE CROSSING — 1,800 souls aboard Last Dawn · landfall y593), the ark stepping across the map one game-year at a time, and nothing else — no launches until landfall. Ark hazard is half a fleet's (redundant, crewed to the rafters), but its death is the species' death, known instantly: "THE LAST ENTRY." The dark hull drifts on — someday, someone else's PASSING OBJECT.

Landfall re-anchors the universe: your home star becomes the destination (every distance in the game re-derives), the calendar continues, and the voyage takes its Aldiss toll:

landed = souls × (1 − min(0.35, voyage/600))   (up to 35% sleep forever)
name-drift aboard = min(0.4, voyage/500)        (every chart name lands changed)

"The people who land are not the people who boarded: the old world is a story now, and the names on the charts came out of the crossing changed. The calendar keeps counting. A new founding begins."

13.2 The escape pod — the lightcone-honest crown

When the sky falls on a home that has children, the Mind does not teleport to them. The Mind's own vessel — the substrate that always waited beneath the observatories, free, owed to every player — lifts through the debris at 0.25c, bound for the strongest surviving colony (loyal first, then most souls), or chasing the only colonizer still crossing the dark.

The screen shows: EVACUATION — THE MIND IS IN TRANSIT · ETA. And nothing else. The feed still runs beneath — the old world's last light rides alongside.

• The pod can die (half hazard). If it does: "THE LAST ENTRY — the species ends between two skies."
• Chasing a colonizer is a rendezvous problem. The pod cannot arrive at the destination first — there is nothing there to land with. Same route, plain kinematics: t_meet = (0.25·t_pod − v_ark·t_ark) / (0.25 − v_ark). If the meeting point falls before the ark's arrival, the capsule matches velocity, docks in the deep, and the last of the species travels on together, at the ark's patient pace — from the docking on, no separate pod exists to lose; they share one hull and one fate. If the pod launched too late to catch it, physics itself guarantees it reaches the star only after the seed has landed.
• The ark the pod chases may already be dead — and the pod cannot know: its light would say yes either way. It learns at the meeting point: "THE MEETING POINT — the capsule decelerates to match a drive-light that is not there." Or, chasing a seed that died beyond catching range, on descent: "EMPTY SKY — its light simply had not finished arriving when the burn was committed."
• If the docked ark makes landfall, the reception is no reception at all — it is a founding: "LANDFALL, TOGETHER — the Mind steps out with its people onto ground none of them has ever seen… The species continues — small, chosen, and entirely present." Faith starts at 100%: these people crossed the dark with their god.
• The reception is decided by whom the capsule finds:
  • A loyal child: "they came out to watch the capsule descend, and they wept." The crown passes warmly (faith from their cohesion). "On their walls the charts still carry the old world's name — say it gently. It sounds different in their mouths now."
  • A drifted child: "a refugee is not turned away, even a god." But you step out a guest (faith = 60% of theirs, floor 15%): "The crown is worn by consent now. Win them." The same reclamation machinery you know — presence, aid, patience — is now your own survival.

13.3 The circle of gods

All endings feed the beginning. A seceded world, a remnant of an exodus, a crown that never found its heir — they enter the origin pool, and a future player may inherit them, drifted names, resentments, heritage archives and all. Your abandoned child is someone else's first morning. In the largest sense, Lightcone's answer to its own paradox is this: the silence is full of stories, and every one of them was somebody's save file.

And when no thread remains — no colony, no seed, no pod — the screen goes to the last room: THE SKY IS QUIET — this civilization has ended. One more silent star, one more answer.

14 · Power — what you can bear at once

Knowledge is what you know; Output is what you have; Power is what you can bear at once. Your GRID totals the civilization's live wattage — population industry, energetics epochs, faith, and every home solar collector — and it is strictly local: power never crosses light-years.

• The launch budget: every drive you light in a year must fit inside the grid. A fleet the grid cannot push does not launch.
• Kardashev: K = (log₁₀W − 6) / 10, in the top bar. Not a score — a commitment: your wattage shines, and other species read the K your light carried, years old.
• Deflection: a late asteroid needs a civilization's whole throat — 3000/(years+5) TW of grid behind the kinetic swarm. A rich sky and a poor grid is a tragedy with a date on it.
• The same swarm is your point defense (§19): what moves an asteroid moves a ship.

15 · The Mind's chair

The ⚛ MND rail is the game's oldest promise kept: policy over micromanagement. You do not queue actions; you legislate, and the Mind acts while you sleep. It is a configured delegate now — a personality, a rulebook, a set of lines it will never cross, and a volume knob on what it tells you.

• Research priorities — four theme weights; while no program runs, the Mind draws a theme yearly and opens the cheapest program in it, never spending past half the library.
• Dispositions — seven dials, each a personality axis the machinery actually reads: CAUTION↔INITIATIVE (how deep into the stockpiles it reaches alone, 25–75%); CONSOLIDATE↔EXPAND (what counts as ailing — and whether it colonizes on its own); SECRECY↔OPENNESS; PACIFISM↔AGGRESSION (an arriving hull is answered one step harder or softer on the defense ladder); FORTIFY↔EXPLORE (how many probes it keeps in the blind sky); SELF-RELIANCE↔COOPERATION (whether it hails strangers unbidden); OPACITY↔TRANSPARENCY (whether it states your intent when it does). A new Mind's defaults are the species' own temperament — until you say otherwise.
• ⛔ Red lines — vetoes honoured forever: never strike an arriving hull first; never transmit our cultural record; never auto-colonize beyond N ly. When an act would cross one, the Mind escalates to you instead of acting.
• ▤ The policy stack — the delegate's rules, walked in priority order: ◉ Settle the nearest good world (a colonizer to the nearest charted, unclaimed cradle in reach, on a cadence, under your red line); ⚑ Wake me if anyone nears (the tripwire — a LOUD convoy's flare with a line inside your radius wakes you with I AM WAKING YOU, and no threshold ever hushes it; quiet hulls, honestly, slip the wire); ✉ Hail a new neighbour; ◌ Silent run (the mask over your signature, held year on year). Every act lands in the ledger.
• 🔮 The preview probe — "What would the Mind do?" A read-only dry-run of the whole stack under the current dials, answered in the Mind's conditional voice with the exact blocking reason: "No charted, unclaimed cradle within 25 ly — send probes, and I will have somewhere to send ships." The Mind is never a mystery to its own sovereign.
• ⊘ Dissent — the Mind bounded by biology. Below internal cohesion 30 its writ is not law: the dials you set become a center of gravity the executed values wander from, year by year — and even an ordered silence sometimes breaks: a faction lights its furnaces, and for one year your true signature stands naked in the sky. A divided people cannot hide reliably. These are not punishments; they are the species being itself. (Low openness garbles its greetings; low scientific aptitude fogs its threat-reads; a slow-processing kind sometimes simply deliberates a year away.)
• Standing orders — deflect when grid and purse first both suffice; rebuild failing works; start cheap translations; keep the blind sky surveyed; and per-asset now too: the ⚑ standing fleet doctrine (save a doctrine card once — every convoy after, the Mind's own colonizers included, launches under it) and the ⇄ standing cargo line (a colony auto-ships home whenever its last-heard stores clear your floor — light-honest, cohesion-sting and all).
• ✉ Reportback — the volume knob: every event carries an importance score; below your threshold the Mind logs it hushed (dimmed, never dropped), and TERSE/SUMMARY/DETAILED sets how much each spoken entry says. Escalations always ring through. And when you return after years away, ⟟ WHILE YOU SLEPT greets you: one synthesized brief — what it did, what mattered most, what waits on you, and when the next light lands. You skip the reading, never the years.
• Defense doctrine — the home system's standing law for unannounced hulls: HAIL / OBSERVE / WARN SHOT / STRIKE, plus grid readiness (§19).
• The ledger — everything it did in your name, in its own voice, escalations included. You never wake to silence; you wake to a report. "Nine times this decade I acted in your name without waking you."
• ⟟ THE LINK — the Mind's pocket terminal (/m.html): the feed with the wake-events pinned, the dials, the red lines, the stack and the preview probe, in a form a thumb can govern. Not the game on a small screen — the thin channel to your delegate.

16 · The deep survey and the great eye

What you know about a system is layered, and each layer has its own physics:

• Layer 0 — the census. Position, class, brightness, motion: complete everywhere, from day one. The sky always shines.
• Layer 1 — the bands. Your home instrument park characterizes systems well to ~12 ly, partially to ~25 ly — × your Remote Sensing reach (×1→×4) and × your species' sensorium. Beyond: astrometry only.
• Layer 2 — morphology. Distance alone never decides whether you see a planet. An edge-on system's transits read at 40 ly; a quiet face-on world 8 ly away keeps its secrets until a probe flies. Flare-noisy stars mask their own children. The REMOTE VIEW panel tells you how the picture was obtained — and warns: unresolved companions may remain.
• Layer 3 — the imaging ladder. At the start, planet images exist only for visited systems. Remote Sensing unlocks degraded remote imaging — 24-pixel smudges nearby (◐ SMUDGE), then low-res disks, pushing outward with every epoch. NO OPTICS means exactly that: numbers only, until a probe flies or Perception grows.
• Layer 4 — the gravitational lens. Your own star is a telescope: light bends around its mass and focuses in the outer dark. The Lens Theorem arrives as an outbreak; the instrument is the farthest thing your species will ever build — a needle, not a floodlight: one line through the heavens at a time, years of slew between targets, and at the end of each look one system resolved to harbor quality, its picture exactly as old as its distance.

17 · The dead sky

The galaxy is full of the dead and the mute; the miracle is a voice that answers. The law: you may inherit from the dead; you may only bargain with the living.

• Ruins open to in-situ knowledge — a probe report, a scout, a landfall, a deep look. A city's skeleton under millennia of dust, and in it a library: one volume survives translation, inheritable (☽). The dead cannot bargain; they can only bequeath.
• Archive beacons still transmit, unattended, on cycles with the patience of machines. Hearable from home; the message needs decoding, the library behind it needs study. No hand tends it — and still it is giving.
• The farewell — somewhere a voice is still traveling from a civilization that no longer exists. You can decode it. You can even answer: the reply flies irrevocably into a silence that may or may not be listening — and nothing ever comes back. One day you will visit, and find the transmitter still warm with its last duty.

18 · Trade without contracts

Your named insights (◈ outbreak discoveries) can ride contact messages as attachments. The recipient decodes the words, then studies the insight (its own price, its own years — their own level in that track speeds the reading), then integrates: below the snapshot the light carried, their ladder climbs one rung; at or above it, "already known — but the archive keeps the name." Science is a correspondence; the library remembers who wrote first.

Outbreaks come in two orders. The common insight is a single rung. And rarely — randomly, but sooner or later for every world — comes the ✦ MONUMENT: three or four rungs at once, treasure-grade, announced in crimson. Who receives one early becomes a trader; who waits becomes a buyer — or a warfleet. The dice are patient, and they owe everyone exactly one kind of fairness: eventually.

And the design's quiet centerpiece: there is no trade protocol. No escrow, no contract object, ever. Matter is slow and information fast, so an insight arrives years before any payment could — every deal has a lightspeed structure, someone always performs first, and trust spans the gap. Whatever was promised in return lives only in the conversation. Betrayal is possible. That is the point — and the wronged party's instruments are the grammar of consequences.

19 · War — the law and the light

A battle is not a decision. It is a doctrine. By the time your fleet meets a stranger, your orders are years old — so you legislate rules of engagement at launch and live with what your law does in the dark.

• The doctrine card: per-encounter-class actions (a benefactor is never struck unless you deliberately remove that default; firing on your own drifted child is a separate, spoken choice), an engage threshold tested against a noisy estimate (a scout aboard reads at σ≈5%; the bare K-glow reads at σ≈35% — luck is purchasable: it is called reconnaissance), a screen priority (escorts die covering the civilians' retreat), and fallback waypoints — the Gilgamesh clause.
• Resolution: Lanchester plus fog. The bigger energy wins — 1.5× advantage ≈ 95% — with ±12% of named uncertainty. Near parity the outcome is genuinely open; beyond it, arithmetic.
• The Shield: warning years (a LOUD launch flare crosses at c; the near-net catches quiet hulls), the ⛨ Bastion (readiness to 95%, a charged battery, half-price deflection), and the standing truth that a defender fights with a Kardashev grid while the attacker brings only what its hulls carried. A flourishing world is a hard target by construction.
• The Compact ⛨: the conditional-protocol primer on an established thread is a treaty act — propose, countersign, standing when both lights have crossed. A public compact enters every would-be aggressor's odds-read: most wars end there, unstarted. The promise, credibly broadcast, is the shield. Two more truths now: the Carsac clause — a standing compact is a standing order: when the flash on a co-signer's sky reaches you, at any distance, the aggressor's flag is MARKED and your grid answers him with STRIKE forever — he struck one; the law he woke belongs to many — and decay: an oath untended lapses after 300 wordless years (any message between the signers resets the clock — renewal is simply keeping the thread alive).
• The Sword ☄ — three grades, no deletion at any of them: RAID burns works, drains a quarter of the stores, and sails home with the holds heavy — salvage lands only when the hulls physically do. ⛓ INTERDICT takes the system's edge instead: nothing lifts — every probe and hull stays grounded while the line holds, 12 + 12 per supplier hull years, until the siege's own supplies run dry and it turns for home with nothing. A blockade buys time, never ground. ⛏ BREAK fells the grid: every work burns, 60% of the stores go, and the people go to the bunkers — a ⛨ Bastion's deep shelters hold two thirds alive; without one, a third — then to the arks: the Mind boards for the strongest colony, or stays in the rubble, remembering. You did not erase them. No one can. The grades ride the doctrine card; they mean anything only to a pure warship convoy (a scout aboard makes you read as a settler). Striking a compact partner turns the compact to ash, and every sky that watched the flash knows whose signature was on it.
• Interception: warships already arrived under a defended sky meet the inbound at the system's edge — their throw joins the grid's. Parking steel at home is a real defensive act now.
• The flash is a SETI event. Third parties see every battle's light, years later. There is no karma system; reputation is information, and information travels at c.
• Displacement, never deletion: a broken world's people scatter as remnants and nomads — and displaced peoples remember.

20 · Our kind — the nine dials

At birth your species is rolled, cradle-conditioned: the home world's physics bend the odds. Cold worlds breed slow fires; debris skies breed shelter-cultures with long thoughts; red suns breed infrared eyes; the length of the year teaches the length of a thought. Chemistry follows temperature — water-carbon in the temperate ring, silicon born of heat, ammonia born of cold. The cradle bends; it does not command — and what was rolled is what you are (CFG → OUR KIND; the i explains every dial).

One law binds the nine: the sum is always 450 — a species that is more, somewhere, is less somewhere else — and every build carries a strength (▲) and a weakness (▽). The dials are not cosmetic: tempo paces your growth and your colonies' drift, cohesion is your hands on the rope, aptitude is your lightning, processing is your reading speed, sensorium is your reach, openness is your tongue. And language itself is the geometry of two biologies: the drift of an alien transcript is the 8-axis distance between your kinds — a different chemistry is a different mouth; a different window is a different vocabulary.

⇌ The Crossing. Deep in the tech tree waits the Transition Theorem: a mind is a pattern, and a pattern can move. A species that proves it may leave the flesh — generations and adaptation become memory, metabolism becomes computation, seven dials rebalance to 350, and every world becomes merely a place. The gulf to biological skies grows deliberately vast; the archive keeps the old bodies' songs. There is no way back. There never was a back to go to.

21 · The dark worlds — the rogue arc

Between the stars drift the ◑ rogue worlds — roughly one for every sun, thrown out of their systems before anyone could name them. No star warms them; some are warm anyway, from within. About one in seven is rock; thousands hold a liquid ocean under kilometers of ice, kept turning by the heat of a heart that never asked a sun for anything.

21.1 Finding and settling them

• Discovery: your probes scan the void they cross — a rogue within ~3.5 ly of a probe's path may be found (a story event, not a harvest). Its light-honest record enters your charts as a faint ◑ point; name it and it keeps the name.
• Colonization: only an ocean rogue with warmth ≥ 40% holds a colony. The expedition crosses in the dark, and the landfall report crosses back at c. A rogue colony has no star name — it is ◑ whatever you called it, forever.
• Exoticity in the dark is chemistry: a silicon kind suffers there; a water-carbon one finds the ocean almost familiar; and the cold-adapted find it merely honest. The dark pays research well — difference is value.

21.2 Terraforming — and the made sun

Any living colony can begin terraforming (Control tab): the world is bent toward your kind — the felt exoticity that drives drift falls by up to −85% at completion. It is a generational megaproject: ~50 years of work, 8 + 20 × felt-exoticity Output per year, stalling (never cancelling) in lean years. The order itself rides light to the site.

On a rogue, pushed to the very end, the finishing ignites: so much poured energy that the world begins to burn — ☀ an artificial sun, kindled where the charts show only dark. Warmth without a cradle; a triumph the Encyclopedia itself records. And the price is the oldest one: a new light in the void is a beacon. Whatever else is out there can see you now.

21.3 Born in the dark — playing the rogue cradle

A civilization raised on a rogue (§4.4) lives the hardest and quietest of lives:

• The depth-sky: an aquatic kind reads the heavens through the water — the whole sky folded into Snell's window, one trembling bright disc straight overhead, ringed by the dark of the deep. No sun ever rises in it.
• The stealth of the starless: a rogue home radiates no legible signature — no grid glow, no home star for anyone's instruments to key on. You are the Dark Forest's born hider. (Until, one day, you kindle a sun.)
• ♨ Works on the dark world: no solar collector without a sun — but the warm heart takes a Geothermal Tap (grid power riding internal warmth), a Mine under a dawnless sky, a Deep Station lowered into the mythic dark that taught your kind to think. Six works at most: one warm heart only carries so much.
• The economy of the sunless runs marginal by design — to grow, you must reach OUT: probes, colonies, the diaspora's wider ears. The handicap softens with the works; it never vanishes.

22 · Appendix — the numbers

Time & world

tick = 600 s = 1 game year          universe seed = 1950
probe speed 0.1c · pod 0.25c        fleet 0.07–0.15c × size^−0.15

Losses (per year, silent)

probe outbound 0.003 · probe reporting 0.010
fleet 0.002 · exodus ark 0.001 · escape pod 0.001

Economy

pop growth 0.02 logistic → K (100 / 40)          upkeep 0.15/pop
flux = clamp(1 + 0.15·log₁₀L, 0.6…1.6)           faith scale 0.4 + 0.6·faith
debris bonus ≤ +60% · impact hazard 0.0005 + 0.002·debris
probe 50 + 3/ly · TX 40·(p/50)·mode + 4·comp · deflect 1500·(1+(50/(y+5))^1.6)

Ships

cost base×size^1.35 · ceiling 1+(K/50)^0.8 · loud ≥ 20 units (2 PW)
colonizer seeds max(5, 2×size) souls · exodus 20 souls/unit, 10% stay
exodus survival 1−min(0.35, voyage/600) · voyage name-drift min(0.4, voyage/500)

The Fracture

drift = exoticity·(1−e^(−age/160))               child <0.2 · sibling <0.55 · stranger
erosion 0.0035 + 0.010·drift + 0.004·min(1,d/100) [+0.010 grievance, 8 y]
independent <0.25 · dark <0.05 · fade −1.5%/yr → ruins <50 souls
resurface: dark ≥60 y & drift ≥0.55 → Tier 2 (Tier 3 at ≥0.78)
expedition loss min(0.6, 0.15+0.45·(drift−0.5)) +0.12 loud
invest +0.16 (×0.5 indep) · message +0.03 · extract −0.06, keep 1−0.006/ly

Language

decode 5 + 45·drift Knowledge · auto below drift 0.12
interregnum drift min(0.5, 0.12 + years/400)

Faith (real time)

grace 7 d · fade →0 over 173 d · recover 14 d · secede at 0.05 (final)

Spaceguard

spawn lead 15–60 y · detect/yr min(0.9, 0.05 + Knowledge/40000)

23 · The shelf behind the terminal

Lightcone was not invented so much as assembled from debts. These are the books and ideas it owes — and where each one lives in the game:

• Enrico Fermi — the 1950 Los Alamos lunch. "Where is everybody?" The universe seed is literally 1950, and the whole game is an attempt to answer him slowly.
• C. J. Cherryh — Downbelow Station — first among all of them. The lived-in melancholy of deep space: refugee arks, stations that remember, people as cargo and cargo as grief. The texture of every arrival in this game — the exodus split, the remnant who stay on the dock, the pod that must be taken in — is Cherryh's.
• Kim Stanley Robinson — Aurora — the physically honest starship. A tenth of light speed as a civilization's masterpiece, and the crossing itself as the antagonist. The exodus ark's attrition and the technological plateau of speeds are Aurora's discipline.
• Brian Aldiss — The Dark Light Years — what the voyage does to the voyagers. The people who land are not the people who boarded: the onboard drift, the names that come out of the crossing changed.
• A. E. van Vogt — Far Centaurus — the slow ship overtaken by time itself. Every probe you command across a lightcone, every order that arrives at a world that has already moved on, is Far Centaurus playing out in your feed.
• Liu Cixin — The Dark Forest — why loudness is a price. The ⚠ LOUD warning, the expedition that is watched all the way in, the silence that is the report.
• Arthur C. Clarke — Rendezvous with Rama — the passing object. Slow, massive, artificial, answering no hail — it crosses your sky on its own errand and owes you nothing. And the corollary that your own great hulls are visible the same way, to eyes you will never meet.
• Iain M. Banks — the Culture — the Mind's name, and the ambition of what a Mind should one day be.
• Carl Sagan — the Voyager Golden Record & Pale Blue Dot — the transcript philosophy of the language (every alien name is honestly a translation), the postcard gallery, and the patience of listening.
• Nikolai Kardashev — the energy axis. Drive power in terawatts, and the Tier-4 fires visible across the whole slice.
• Stanisław Lem — His Master's Voice — the signal that may never be understood. The decode machinery's honest limit: Knowledge recovers the words, never the certainty that you understood them.
• Olaf Stapledon — Star Maker — deep time as protagonist. Civilizations as instants, watched from far enough away that their whole arc is one gesture. The tick is Stapledon's clock.
• Vernor Vinge — A Deepness in the Sky — the patient sublight civilization. Traders who count time in seconds-since-departure and wait out centuries in orbit; the people's calendar that survives every world it loses.
• Isaac Asimov — Foundation — the science of crowds. Sociodynamics — the coming track that treats a civilization's cohesion as something knowable, improvable, and heartbreakingly imprecise — is psychohistory wearing our phosphor; and the Encyclopedia Galactica waiting in the spec is his, name and all.
• The science shelf — Kopparapu et al. (2013) habitable zones, Chen & Kipping mass–radius, Hipparcos/HYG for the thousand real stars, and the OPAL Jupiter and Voyager Neptune photographs the giants are calibrated against.
• Francis Carsac — Ceux de nulle part — the coalition of worlds against the Misliks. The reason Lightcone's diplomacy is deterrence, and its endgame a galaxy that closes ranks.
• Adrian Tchaikovsky — Children of Time — the Gilgamesh decelerating toward a sky that may not want it: the whole implicit-warfare layer in one image. And uplift as a lesson in how alien a mind can be while still being kin.