Gravity – Interactive solar-system simulator, from Newton to Einstein
Just for fun and self education, I've built this over a weekend to teach myself why orbits exist, not just show planets going around. Something that was never clearly explain to me in school. It opens with a guided tour that builds the idea up step by step: two bodies and the equal/opposite force, inertia (the Sun is removed and Earth just drifts straight), then "an orbit is falling and continuously missing," cosmic velocities with a little rocket, Voyager 1 & 2's real gravity assists (the clock runs the actual 1977–1989 dates so the planets orbit into their grand-tour alignment and the…
In plain words
Gravity is an interactive solar-system simulator that explains orbital mechanics through hands-on exploration. It opens with a guided tour building understanding from basic physics—Newton's laws, inertia, and gravity—through to Einstein's curved spacetime. Users can watch real gravity assists of Voyager 1 and 2 unfold with actual 1977–1989 dates, adjust cosmic velocities with a virtual rocket, or switch to N-body simulation mode. All bodies use real masses, radii, and orbital elements calculated from Kepler's equation. It's designed for self-education and casual learning about why orbits exist.
written from the facts on this page · September 2026
From the sources
In the maker’s words, at launch
Just for fun and self education, I've built this over a weekend to teach myself why orbits exist, not just show planets going around. Something that was never clearly explain to me in school. It opens with a guided tour that builds the idea up step by step: two bodies and the equal/opposite force, inertia (the Sun is removed and Earth just drifts straight), then "an orbit is falling and continuously missing," cosmic velocities with a little rocket, Voyager 1 & 2's real gravity assists (the clock runs the actual 1977–1989 dates so the planets orbit into their grand-tour alignment and the slingshots line up), and it ends on Einstein — gravity as curved spacetime, the classic rubber-sheet well. What's real: every body uses its real radius/mass and J2000 orbital elements; positions come from solving Kepler's equation each frame. You can toggle to an N-body mode (symplectic leapfrog) that shows live energy drift (~1e-6%) so you can see the integrator is honest. The only thing faked is scale — at true scale you can't see anything — so there's a toggle between true scale and a log-remapped "visual" scale, with physics always running in real AU. Tech: TypeScript + Three.js + Vite, fully client-side, no backend, works offline (surface textures are generated procedurally from value-noise; only Earth uses a real image). Source: https://github.com/qunabu/Gravity Happy to answer questions — and feedback on the physics or the explanations is very welcome. This project might be totally inaccurate in terms of real physics, this is how i do understand this on my own - i'm happy to confront this with reality
More life & fun this month
the category →- TL
Life & fun · 10d ago · louisabraham.github.io
Photosynthesis fires two of your iPhone
Life & fun · 28d ago · photosynthesis.camera
SoloUno▲310Take control of hair pulling, nail biting & skin picking
Life & fun · 28d ago · solouno.io
Scroll through all 43,252,003,274,489,856,000 reachable Rubik's Cube permutations.
Life & fun · 26d ago · everycube.alen.is
Hi HN, I built Eigendrum, a web tool that solves the 2D wave equation for arbitrary shapes so you can hear what they sound like as drums. How it works: * Solves -∇²u = λu using finite element analysis (Kφ = λMφ) on a triangle mesh. * Validated to <0.1% error against closed-form solutions for circles (Bessel zeros) and rectangles. * Sound model factors in strike location, Rayleigh damping, and mallet width. * Includes Kac drums I & II to demonstrate identical sound spectra from different geometries. * No frameworks, build steps, or dependencies. Repo and tests:…
Life & fun · 27d ago · baselashraf81.github.io
Launched alongside, June 2026
the whole month →
Fundraisly▲1,544AI fundraising agent that finds investors and books meetings
AI · Jun 2026 · fundraisly.com
- H6Homebrew 6.0.0▲1,481
Today, I’m proud to announce Homebrew 6.0.0. The most significant changes since 5.1.0 are a new tap trust security mechanism, the new faster, smaller, default internal Homebrew JSON API, sandboxing on Linux, better defaults informed by our user survey, many brew bundle improvements, improved performance and initial support for macOS 27 (Golden Gate). Happy to discuss any questions here!
Dev tools · Jun 2026 · brew.sh
- PU
hope you enjoy
Life & fun · Jun 2026 · vorpus.github.io
- IM
Life & fun · Jun 2026 · hackernewstrends.com