Browser-based solar system simulator models gravity from Newton to Einstein

A developer has released Gravity, an interactive solar-system simulator that runs in the browser, shared as a Show HN project. The simulator’s premise is to let users explore orbital mechanics across two regimes of physics: classical Newtonian gravitation and Einstein’s general relativity, making the differences between the two frameworks tangible rather than purely theoretical.

The project is hosted on GitHub Pages, suggesting an open, freely accessible tool aimed at education and experimentation rather than a commercial product. Tools like this fill a useful niche: relativistic corrections to orbital motion — such as the precession of Mercury’s perihelion, which Newtonian mechanics famously fails to explain — are usually confined to textbooks, and an interactive visualization lets users see where the simpler model breaks down.

The source article provides little detail beyond the headline, so specifics about the simulation methods, accuracy, or feature set aren’t available here. For technical readers, the interesting questions will be how the simulator integrates the equations of motion and how faithfully it approximates relativistic effects at solar-system scales — answers that require trying the tool directly.