No shared present
Messages and people move at light-speed limits, so years to decades of delay are ordinary.
Setting guide
Humanity does not conquer the stars. It extends its constraints into them.
This page tracks the latest canon: the world rules, transport model, network structure, and political logic of The Light Between. Where a section depends on specific equations or scaling laws, it links to the matching Physics section.
No FTL or shared present
Typical cruise at 0.03c-0.1c
Power means control of constraints
Physical constraints
The setting starts by refusing the usual sci-fi escapes.
No FTL travel. No FTL communication. No exotic shields, artificial gravity, or reactionless drives. Typical interstellar cruise sits in the 0.03c-0.1c range.
No exotic escape hatch
Passive armor exists, but there are no force fields, no gravity hacks, and no reactionless propulsion.
Throughput-limited civilization
Energy is abundant at system scale, but usable high-power throughput is heat- and schedule-limited.
Energy is abundant. Throughput is not.
Solar civilization chokes not on raw energy scarcity, but on heat rejection, precision control, infrastructure congestion, and political allocation of duty cycle.
Physics link: Radiator scaling at infrastructure scale
Civilizational driver
Interstellar expansion emerges from Sol system maturity, not a miracle invention.
The enabling stack
- Autonomous industrial systems
- Cheap mass movement to orbit and between nodes
- Asteroid extraction for structure and volatiles
- Large-scale solar power infrastructure
- Beam-based power transmission and momentum transfer
- Advanced high-temperature, high-precision materials
- Later supplementary fusion systems
Why Sol saturates
- Thermal congestion: the hottest nodes cannot run everything continuously.
- Infrastructure interference: arrays, industry, logistics, and habitats compete for timing.
- Duty-cycle scarcity: beam time becomes politically contested.
- Capital lock-in: giant thermal systems are expensive and fragile.
- Throughput politics: safe, continuous power allocation becomes governance.
Corridors externalize growth and risk by turning constrained local power into outbound momentum.
Physics links: thermal bottlenecks, cooling layers, campaign energetics
Corridors and transport
Corridors are beam-driven transport systems coupled to timing, heat, and capture.
Corridor model
Corridors are synchronized transport events, not simple routes, and they bind origin and destination infrastructure together.
Transport architecture
Packets are beam-coupled mission stacks with beam interface, payload, spine or tether, thermal surfaces, and guidance.
Dual-interface standard
Mature packets separate launch sail and brake sail because acceleration and deceleration are different engineering problems.
Conceptual beam-sail packet
A transport packet is not a cinematic starship. It is a beam-coupled stack: sail forward, payload mass aft, thermal surfaces spread where needed, and guidance keeping the whole geometry stable over a very long push.
Transport classes
- Class I: rugged cargo with broader capture margins.
- Class II: fragile technical cargo using precision braking.
- Class III: human torpor transport with full redundancy and the strictest limits.
Physics links: beam mechanics and sail heating, beam energy budget, layered capture sequence
Network structure
The network is sparse, route-dependent, and historically uneven.
- Layer 1: Sol backbone Corridors at 100-500+ TW scale.
- Layer 2: regional and colony systems at 10-50 TW scale.
- Layer 3: opportunistic and low-confidence routes.
Proxima
First Corridor, Sol-aligned, and burdened by old standards.
Alpha Centauri
Emerging routing authority and the first autonomous return node in Centauri.
Tau Ceti
High-performance capture architecture and the cleanest mature non-Sol system.
Epsilon Eridani
Environmental assumptions and reality fail to align cleanly.
Wolf 1061
A late political route whose inefficiency is partly an expression of independence.
~150 CA (Corridor Age) network state
Sol still dominates the backbone. Multiple colonies possess uneven Sol-return capability.
Only one fully operational inter-colony Corridor exists: Tau Ceti ↔ Alpha Centauri.
Physics links: example beam-array scales, capture geometry
Mandates and military
Force projection is mostly about capture control, infrastructure seizure, and delayed authority.
Mandate Groups
Mandates are finite, semi-autonomous enforcement formations dispatched under pre-authorized directives. They secure Corridors, deter threats to continuity, and protect human-rated transit.
- Autonomy-heavy: command cores, escorts, drones, seizure and engineering units.
- Bounded autonomy: mission-tree logic, not general intelligence.
- Crew-light: operational viability cannot depend on successful revival.
- Infrastructure doctrine: seize arrays, radiators, depots, and sensors before trying to destroy fleets.
Colonial Military
Colonial military systems prioritize continuity of beam arrays, radiators, sensors, depots, hospitals, and fabrication lines. Conflict is usually thermal denial, schedule interference, capture access control, and dependency manipulation.
Physics links: deep deceleration and arrival vulnerability, why thermal denial can bite quickly
Economy and cargo
Interstellar exchange is low-volume, high-value, and justified by difference rather than scale.
Cargo doctrine
- Control and cognition cargo
- Precision technical cargo
- Industrial seed cargo
- Infrastructure concentrates
- Biological and medical cargo
- Rare human-rated transport
- Limited rugged bulk-strategic cargo
Physics links: campaign-scale throughput limits, why speed is expensive
Economic insight
Colonies do not outcompete Sol on raw scale. They matter because they generate divergent industrial processes, local knowledge, specialized manufacturing, and political alternatives.
Value in this setting comes from difference, not abundance.
Physics link: campaign energetics and why bulk cargo does not pencil out