Project ideas from Hacker News discussions.

Show HN: Physically accurate black hole you can put in your room

📝 Discussion Summary (Click to expand)

3 Prevalent Themes

1. AR tracking relies on phone sensors & SLAM

"First time I have AR’d. That was cool. How does it keep the hole in the same point in space as I walk about?" – hahahaa
"Your phone has an accelerometer, which can be integrated twice to result in slightly accurate dead‑reckoning; just keep accumulating 3‑vectors with every time‑slice. That's a helluva lot easier than visual cues." – boothby
"\"SLAM\" is the term to google." – dmd

2. The simulation is marketed as “physically accurate” but is heavily simplified

"Its titled a \"physically accurate black hole\"! Please don’t do this, if its intentionally not physically accurate and heavily simplified!" – 20k
"The accretion disk shouldn't be red, people just expect it because it looks cool. Black‑hole accretion disks are near universally hot enough to be blue." – 20k
"The rendering is also done without taking into account sRGB, and its colours are wrong… the doppler isn’t terribly accurate." – 20k

3. Black‑hole visualisations trigger genuine fear / “melanoheliophobia”

"If somebody feels no fear while zooming towards a black hole, their brain has some strange wires crossed." – chamomeal
"VR is fine when it's small cute bunnies… but a massive thing that tricks my brain like the edge of a gas giant is terrifying." – dluan
"Melanoheliophobia… the Greek term is “mayri trypa”, literally “black hole”." – stavros


🚀 Project Ideas

Generating project ideas…

AR Black Hole Anchor

Summary

  • Provides persistent spatial anchoring for virtual black hole objects so they stay fixed as the user moves.
  • Solves the drift and “lose‑track” frustration reported by AR newcomers.

Details

Key Value
Target Audience AR hobbyists, educators, and developers building location‑aware AR experiences
Core Feature Persistent anchor tracking using cloud‑based spatial maps + low‑latency SLAM fusion
Tech Stack Unity + ARCore/ARKit, Cloud‑based spatial anchors (Google Cloud Anchor, Apple ARCocean), Firebase for sync
Difficulty Medium
Monetization Revenue-ready: Subscription (monthly tier for premium anchor features)

Notes

  • HN commenters asked “How does it keep the hole in the same point in space as I walk about?” – this product directly answers that.
  • Potential for community‑driven anchor sharing (e.g., “my black hole place” gallery) to spark discussion.

SLAM Explained – Interactive Learning Platform

Summary

  • Breaks down SLAM concepts (visual odometry, IMU integration, drift) into bite‑size interactive tutorials.
  • Addresses the “How do phones do that?” curiosity from the thread.

Details

Key Value
Target Audience Students, developers, and curious HN readers with little SLAM background
Core Feature Interactive 3D visualizations where users adjust parameters (e.g., IMU noise) and see drift in real time
Tech Stack React + Three.js, WebAssembly (C++ SLAM simulation), Node.js backend for user data
Difficulty Low
Monetization Hobby

Notes

  • Directly quotes users: “I guess it uses dead reckoning with visual cues and some machine learning.” – this tool makes those mechanisms explicit.
  • Encourages discussion by letting users experiment and share resulting drift graphs.

Physically Accurate Black Hole Simulator (Mobile)

Summary

  • A high‑fidelity, scientifically‑grounded black hole visualizer with correct accretion‑disk coloring, Doppler handling, and optional Kerr spin.
  • Fixes the “red disk” and simplified physics criticisms from the discussion.

Details

Key Value
Target Audience Space enthusiasts, educators, and astrophysics hobbyists seeking realism
Core Feature Real‑time ray‑marched black hole with physically based emission, proper color mapping, and optional spin/jet visualization
Tech Stack Unity (URP) + Vulkan/OpenGL ES shaders, Swift/Kotlin native wrappers, Unity Asset Store for audio ambience
Difficulty High
Monetization Revenue-ready: One‑time purchase ($4.99) with optional educator licensing

Notes

  • Responds to critiques like “accru... disks should be blue” and “doppler shifting isn’t correct” – the app implements corrections.
  • Appeals to the community of users who posted detailed technical feedback, offering a concrete, accurate tool to explore.

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