Project ideas from Hacker News discussions.

Show HN: What if the speed of light was 5 km/h?

📝 Discussion Summary (Click to expand)

Educational/game applications of relativity simulations: Users frequently referenced and discussed interactive tools like MIT's "A Slower Speed of Light" game for visualizing relativistic effects.

"A Slower Speed of Light is a first-person game prototype in which players navigate a 3D space while picking up orbs that reduce the speed of light in increments... Visual effects of special relativity gradually become apparent to the player"
shagie

Debate over the "speed through time" slogan: A detailed technical discussion challenged the popular science notion that all objects move at c through spacetime, highlighting dimensional inconsistencies.

"Your own clock is one second per second, which is a pure number, 1... that's not a speed... You can't put meters per second on one side and a bare number on the other and call it a triangle."
Kranar

Connections to sci-fi, perception, and real-world tech: Commenters linked the concept to works like Discworld and Three Body Problem, questioned human-scale perception of light speed, and noted implications for technology (e.g., fiber optics, drones).

"The first few Discworld books explore this a little bit too... Darkness travels even faster than light on Discworld, because it has to be fast enough to get out of the way when light arrives."
zrail and yreg (combined for thematic relevance)


🚀 Project Ideas

Generating project ideas…

Relativity Mobile Sandbox

Summary

  • A touch‑optimized web simulation that lets users adjust the speed of light and explore relativistic visual effects on smartphones and tablets.
  • Core value: Intuitive controls, real‑time explanations, and cross‑browser compatibility make learning special relativity accessible anywhere.

Details

| Target Audience | Students, educators, and curious hobbyists who want to learn relativity on mobile | | Core Feature | Interactive 3D environment with adjustable c, touch joystick/movement, visual effects (Doppler, aberration, time dilation), and built‑in tooltip explanations | | Tech Stack | HTML5, Three.js, React (or Vue), Service Worker for PWA, WebGL2 | | Difficulty | Medium | | Monetization | Hobby |

Notes

  • HN users asked for mobile controls: “gryfft: It would be nice to add controls for mobile.” and “buttercraft: This only works on a desktop? Is there any way to interact with it on a phone?”
  • Could spark discussion on HN about physics education tools and serve as a practical teaching aid for classrooms or self‑study.

OpenRelativity Engine

Summary

  • A standalone, open‑source JavaScript library that encapsulates the relativistic rendering pipeline (Doppler shift, aberration, time dilation, Lorentz transformation) for use in any WebGL‑based game or simulation.
  • Core value: Developers can plug accurate special‑relativity effects into their projects without reinventing the physics, ensuring correctness and saving time.

Details

| Target Audience | Game developers, educational software creators, indie hobbyists building physics demos | | Core Feature | Module providing shaders and parameters to control c, velocity, and post‑process effects; includes demo scenes and documentation | | Tech Stack | JavaScript, GLSL, Three.js (or Babylon.js), TypeScript, npm package | | Difficulty | Medium‑High | | Monetization | Hobby |

Notes

  • Commenters highlighted correctness issues: “adamkurkiewicz: … issue that I found was with modeling temporal aspects of the relativistic doppler …” and “TZubiri: … they can take this as a base rather than vibing the physics from scratch…”
  • Enables the community to build variants, fosters discussion on implementation correctness, and provides practical utility for creating new relativistic games or visualizations.

Relativity Lab: Guided Experiments

Summary

  • An interactive learning platform that combines the relativistic sandbox with guided experiment modules (e.g., Young’s double‑slit, Michelson‑Morley, clock‑on‑a‑rocket) where users follow step‑by‑step instructions and see real‑time relativistic outcomes.
  • Core value: Turns abstract formulas into tangible, observable phenomena, boosting comprehension for students and self‑learners.

Details

| Target Audience | Physics educators, undergraduate students, lifelong learners interested in relativity | | Core Feature | Curated experiment scenarios with adjustable parameters, live narration/tooltips, quiz checks, and ability to share results | | Tech Stack | Same as Relativity Mobile Sandbox plus a lightweight backend (e.g., Firebase) for saving progress, React for UI, Three.js for visuals | | Difficulty | Medium | | Monetization | Hobby |

Notes

  • Users expressed desire for educational use: “gigisfndr: … using this as a “time scaled” model to “observe” well known physical experiments … Could that work / be useful?” and “nico_bresson: … a live explanation of what is happening while I'm navigating this virtual world … This would be a great way to learn!”
  • Generates rich discussion on pedagogy and serves as a practical supplement to textbooks or lecture courses.

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