Alternatives to Universe Sandbox
A physics-based space simulator for experimenting with gravity, collisions, climate and stellar evolution. The listings below can replace it for an important use case. Each note says what changes if you switch.
The original
Universe Sandbox
A physics-based space simulator for experimenting with gravity, collisions, climate and stellar evolution.
Replacements
Listings that take over the same core job as Universe Sandbox.
SpaceEngine
A 3D universe simulator for travelling between stars and galaxies and landing on planets.
SpaceEngine is also paid but Windows only, focusing on seamless travel from galaxies to planet surfaces rather than gravity experiments and climate models.
Celestia
An open-source real-time 3D space simulator for exploring the solar system, stars and galaxies.
Celestia is free and open source under GPL-2.0 for 3D space exploration, but it is a viewer rather than a physics sandbox for experiments.
Similar software
Related functionality, not a direct replacement.
Stellarium
A planetarium on your screen showing exactly what is in the sky above you, tonight or on any date you choose.
KStars
A free, open-source desktop planetarium from KDE for simulating the sky and planning observations.
Algodoo
A 2D physics sandbox where you draw objects and watch them move, collide and interact.
Step
A KDE interactive physics simulator for building two-dimensional experiments and watching them evolve.
PhET Interactive Simulations
Free interactive physics, chemistry and math simulations usable directly in the browser.
