Spiral Galaxy Screensaver
The Spiral Galaxy screensaver places a hundred thousand stars on elliptical orbits and lets spiral arms emerge from the orbits themselves rather than drawing any spiral. It runs in the browser with nothing to install; press ESC to exit.
How the Spiral Galaxy screensaver works
The saver renders with three.js on your GPU. The library is vendored into this site rather than fetched from a CDN, and loads only when a 3D screensaver actually runs.
It reads nothing external — the orbits are generated in the browser.
The scene resizes with the window and releases its WebGL context when the saver stops, so shuffle mode and Multi-view can cycle 3D savers without exhausting the browser's context limit.
If WebGL is unavailable the saver says so on screen rather than showing an empty black box.
A worked example
Each star follows an ellipse, and the orientation of that ellipse advances steadily with distance from the centre. Where neighbouring orbits crowd together, stars pile up — and that crowding traces the arms. It is density wave theory in its simplest form, and it answers a problem that troubled astronomers for decades: if arms were physical structures they would wind up tight within a few rotations, yet galaxies are billions of years old.
Settings & tips
- Accent and Background recolour the scene; Speed changes the pace of the motion and the camera.
- Add it to a Multi-view grid, though 3D savers are heavier than 2D ones and a few per screen is plenty.
- Press ESC at any time to leave fullscreen.
Frequently asked questions
- So the arms are not made of fixed stars?
- Correct, and that is the point. Stars drift in and out of an arm the way cars pass through a traffic jam. The pattern persists; the members of it do not.
- Is this a physical simulation?
- Not a gravitational one — there is no force calculation between stars. It is a kinematic model that reproduces the mechanism behind spiral structure without the cost of an n-body simulation.
- Does this need a special browser or plugin?
- No. It uses WebGL, which every current desktop and mobile browser supports. Nothing is installed and no plugin is required.
- Does it cost anything or need an account?
- No. Every screensaver here is free, runs in the browser and needs no sign-up.