Sources and implementation

Original references checked 28 September 2026. Stellar-weather and world-condition references checked 4 October 2026. Engineering and gravastar references checked 7 October 2026.

These sources explain concepts used in the game and the information pages. They are references, not endorsements. External links require an internet connection; the game and its bundled pages do not.

Astronomy references

• NASA Planetary Fact Sheet: reference planetary masses and other physical properties.
• NASA: How did our Solar System form?: molecular clouds, disks and planetary formation.
• NASA: Black Holes: accretion, black-hole classes and related terminology.

World conditions and stellar weather

• NASA: a roaming magnetar: strongly magnetized neutron stars.
• ESA: resonant planetary orbits: repeating period relationships.
• NASA: the habitable zone: stellar radiation and the liquid-water distance range.
• NASA: types of exoplanets: rocky and gas-rich worlds.

Climate, density, flare reach and resonance bonuses are gameplay approximations. The game detects persistent period relationships; it does not solve resonant-angle libration or prove a world is habitable.

What the game simplifies

Logical mass grows through compressed thresholds. Displayed astronomical units do not imply that every numerical ratio is an exact physical model. Time, size, distance and movement are scaled for play. Gravity is softened and limited by distance; stable systems use approximate orbital hierarchies. Gas uses coarse cells and bounded matter parcels. Lensing is a visual displacement approximation. Companions and asteroid DNA are fictional gameplay content. Strange Matter, gravastars and The Interstallar are speculative or fictional game forms. Optional supernova routes preserve mass, and their compressed evolution thresholds do not model actual stellar endings.

Advancement interface reference

The publisher's Advancement Plaques by Grend and its screenshot gallery were inspected on 6 October 2026 for the wide framed notification, inset badge, staged light reveal, and task/goal/challenge hierarchy. Anti-Horizon uses original celestial SVG emblems, CSS frames, typography and procedural chimes. No Minecraft or mod texture, font, artwork, sound or code is included.

Galactic encounter and interface references

ESA/Hubble: star formation in galactic tidal tails informed the bridge, gas concentrations and compressed star-forming passages. The optional two-hour duration, finite gameplay reserves and completion rewards are game rules, not physical astronomical timescales.

CCP Games' Photon UI iteration notes and the linked compact-mode reference image were inspected on 6 October 2026 for dense instrument hierarchy, restrained borders, aligned readings and compact spacing. Anti-Horizon uses original local CSS, vector controls and procedural charts. No EVE screenshot, asset, font or code is bundled.

Engineering interface and gravastar references

The publisher’s Diep.io game and changelog informed the compact colored rank bars and direct upgrade selection. Anti-Horizon uses its own layout, branch names, requirements, artwork and code. No Diep.io assets are bundled.

Kurzgesagt: Black Hole’s Evil Twin, Gravastars Explained is the requested visual and conceptual reference. The underlying Mazur and Mottola gravastar proposal describes a vacuum-energy interior separated from the exterior by a thin material boundary, without a singularity or event horizon. The game now draws a distinct interior and moving surface waves. This is an original interpretation of a hypothetical model, not a confirmed object or a simulation of quantum gravity.

Mining currency, research timing, generators, battery units, combat and overclock bonuses are compressed game rules. Initial stellar systems use orbital velocities; their later stability is decided by the existing simulation. Galactic associations use a few aggregate bodies and nested stars rather than thousands of simulated stars.

Code and assets

The full source is in this package under the MIT license. The graphics use procedural Canvas drawing and local vector artwork. Sound is synthesized with Web Audio. No downloaded stock image, external font, tracking library or third-party runtime library is loaded by the game.

Black-hole optics and original rendering

Version 3.9 adds seven original stage-specific animated Canvas designs, drawn from paths in final-render.js. No photograph or imported black-hole asset is used. Distinct inclinations, flow arms and feeding-dependent jets are artistic gameplay choices; class mass alone does not determine the appearance of a real accretion flow. See design notes.

Black holes in this game are an original real-time rendering inspired by published scientific visualisation. No film footage, images or sound are included. The optional renderer solves a bounded Schwarzschild null-orbit model. Its weak-field point-source lens, finite photosphere, warm grade and display asymmetry are gameplay approximations. It is not DNGR or a full Kerr simulation.

• James, O.; von Tunzelmann, E.; Franklin, P.; Thorne, K. S. (2015). Gravitational lensing by spinning black holes in astrophysics, and in the movie Interstellar. Classical and Quantum Gravity 32, 065001. DOI: 10.1088/0264-9381/32/6/065001. Scientific context for ray bundles and disk appearance, not copied code.
• Thorne, K. S. (2014). The Science of Interstellar. W. W. Norton. Context; publisher title checked, bibliographic year supplied in the brief.
• Luminet, J.-P. (1979). Image of a spherical black hole with thin accretion disk. Astronomy and Astrophysics 75, 228–235. Schwarzschild disk-image context; primary paper and first-page title checked.
• Bardeen, J. M. (1973). Timelike and null geodesics in the Kerr metric. In Black Holes, Les Houches, pp. 215–239. Context for what this simplified model omits. Retrieval of this paper failed here; the bibliographic entry is from the supplied brief, not a claim that the paper was read.
• Event Horizon Telescope Collaboration (2019). First M87 Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole. Astrophysical Journal Letters 875, L1. DOI: 10.3847/2041-8213/ab0ec7. Shadow context, not a texture source.
• NASA Science: Black Holes. Undated overview, accessed 7 October 2026.
• Gralla, S. E.; Holz, D. E.; Wald, R. M. (2019). Black Hole Shadows, Photon Rings, and Lensing Rings. Physical Review D 100, 024018. DOI: 10.1103/PhysRevD.100.024018. Distinguishes the narrow photon feature from broader lensed emission.
• Khronos WebGL 1.0 specification. Context flags, precision and resource-lifecycle guidance; editor draft checked 7 October 2026. No external shader or library is loaded.

Supplied images were privately inspected at their original resolution. Only numerical observations and short fitted colour constants are stored. Reference images, image strips, watermarks, film stills and sound samples are absent from this package. See measurement provenance and the measured CPU fidelity comparison, including its remaining failures.

Dock reference

Apple Support: Desktop & Dock settings informed the compact shelf, subtle icon magnification and hiding behavior. The game uses original vector icons and F-only activation, with no Apple artwork, logo, copied source or external runtime.

Site and policy references

• MDN: localStorage: browser storage and file-page limitations.
• MDN: 404 Not Found: the server status required for missing pages.
• Google Search Central: sitemaps: public URLs and sitemap preparation.
• Google Search Central: robots directives: crawl and indexing directives are not access controls.
• OAIC: developing a privacy policy: describing actual information practices and responsibilities.
• ACCC: consumer rights and guarantees: rights that terms cannot remove where they apply.
• llms.txt proposal: a machine-readable content guide, not a security or compliance guarantee.

Verification

The test report separates automated checks from browser checks that still require verification. Release readiness records the remaining publication requirements. No public user numbers, review scores or performance guarantees are asserted.

Orbital Command implementation

Update guide and multiplayer setup describe the exact mechanics and operating limits. The original procedural renderer is extended in command-rendering.js; no replacement photographs are included.

Starlight graphics layer

Version 4.1 adds graphics.js: a procedurally generated deep-sky backdrop, star-lit bodies, stellar coronas, lit asteroids, horizon emission and softer effects. Every image is generated in the browser from seeded noise; no textures, photographs or external art are loaded. graphics-tests.js checks it inside the diagnostics page.

Prospector fleet

Version 4.2 reworks mining-drone flight and job selection in industry.js and draws the fleet in graphics.js. fleet-tests.js flies a controlled rock course to check formation keeping, delivery, job assignment and orders.

Nebulae

Version 4.3 gives each physical gas type its own procedurally baked glow and dust textures in graphics.js, generated from seeded value and ridged noise in the browser. No images or photographs are loaded.

The optional transport uses the browser WebSocket API. The backend implements a bounded subset of RFC 6455 using Python asyncio streams. These external reference pages are opened only when selected.