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Universe simulator: how Everdust builds the cosmos from particles

What a universe simulator is, how the big research simulations and Everdust's particle universe simulator differ, and what you can do with Everdust, from the Big Bang to colliding galaxies and black holes. Free in your browser, on Android and on Apple Vision Pro.

Faint threads of blue and gold particles crossing a dark field, a frame from the Everdust engine's cosmic web

The best universe simulator depends on what you want: Universe Sandbox ($29.99 on Steam, PC or Mac) is the deepest sandbox, SpaceEngine ($29.99, Windows) flies you through the whole universe at real scale, Gaia Sky and Celestia are free with real star and galaxy data, and Everdust is free on phones, tablets, Apple Vision Pro, Meta Quest and Mac and in a browser, with live galaxy collisions and black holes to play with.

I make Everdust, so this is a guide to one universe simulator by the person who built it. It explains what the phrase means, how Everdust does it and what it leaves out. If you want to compare it with Universe Sandbox, SpaceEngine, Gaia Sky and Celestia, read our honest guide to galaxy and black hole simulators.

The short answer: which universe simulator to pick

  • The deepest sandbox, on PC or Mac: Universe Sandbox ($29.99 on Steam). Build systems, change gravity and smash things together.
  • The whole universe at real scale, on PC: SpaceEngine ($29.99 on Steam, Windows). Fly to any galaxy, star or planet.
  • Free, with real star and galaxy data: Gaia Sky (Windows, macOS and Linux, open source) and Celestia (almost every platform, including Android).
  • On a phone, a tablet, a Vision Pro, a Quest, a Mac or in a browser, with live physics to play with: Everdust (free). Galaxy collisions, black holes and the story of the universe run live as particles.

Prices and platforms are as checked for the galaxy simulator apps guide on October 27, 2026, which compares them all.

What is a universe simulator?

The phrase covers three quite different things.

  • Research simulations. Astronomers model the growth of the universe on supercomputers. The Millennium Simulation, published in 2005, followed more than ten billion particles of dark matter as gravity pulled them from a smooth start into a web of filaments, with galaxies forming in the knots. Runs like it take weeks and produce data, not something you play.
  • Sandboxes and explorers. Programs such as Universe Sandbox let you build systems and change the physics; SpaceEngine and Celestia let you fly through a 3D model of space.
  • Ready-made live simulations. This is Everdust. Each world is one physical process, such as two galaxies colliding or a cloud collapsing into a star, running live on your device as particles you can turn and touch.

How does Everdust simulate the universe?

Everything you see is made of particles, and the particles are moved by rules, frame by frame, on your device's graphics chip. Nothing is a pre-rendered video, so each run unfolds on its own and answers your hands.

The rules are real physics, simplified where a phone or a browser can't do the full calculation, and we say where. The galaxy collision follows the method Alar and Juri Toomre published in 1972: each star is pulled by both galaxy cores rather than by every other star, which is enough to reproduce the long tidal tails of real colliding pairs (more in how galaxy simulations work). In the app it moves up to about a million stars. Black Hole Golf uses a formula that copies how gravity behaves near a non-spinning black hole. The three-body world uses Newton's law of gravity directly.

What Everdust leaves out matters too. It doesn't model the whole universe at once, it isn't a map of real stars, and you can't build a solar system from scratch. Each world is one idea, done live.

What can you do in it?

Follow the story of the universe. In the app, The Story of Everything walks from the Big Bang to today in narrated chapters, and every chapter is a live simulation you can turn while River, the narrator, explains it. It starts with First Light, when the hot plasma of the Big Bang cools until light runs free. Then gravity pulls dark matter into the cosmic web, galaxies collide, a giant star explodes, the Sun is born, and the planets and the Moon form. The Story of Everything is free in full. The Life of a Star, The Life of a Black Hole and The Future of Everything carry on from there.

Collide galaxies. Drag to orbit and pinch to zoom while two galaxies tear into tidal tails and merge.

Play with gravity. The games are built on the same physics: feed a black hole, slingshot round one, or knock over towers under the gravity of other worlds.

Try it in your browser first. A few worlds run free on this site, with the science written under each:

Where does it run?

Everdust is on the App Store for iPhone, iPad, Apple Vision Pro and Apple TV, on Google Play for Android phones and tablets and on the Meta Horizon Store for Meta Quest 3 and 3S, free to download, with no ads. On Mac it's a free download from everdust.ai (version 1.0.1; macOS 14 Sonoma or later, Apple silicon (M1 or later)); the Mac App Store version is in review. The browser worlds at everdust.ai/play run on any recent phone or computer.

The same particle engine also runs in your browser: turn any photo into living particles, free.

Questions people ask

Is there a free universe simulator? Yes. Everdust is free to download on the App Store for iPhone, iPad and Apple Vision Pro, on Google Play for Android and on the Meta Horizon Store for Meta Quest, and The Story of Everything is free in full. A few of its worlds also run free in a web browser at everdust.ai/play, with no install. Gaia Sky and Celestia are free too; they let you explore a model of space rather than run physics like this.

Is there a universe simulator for Android? Everdust on Google Play is one: a galaxy collision of up to about a million stars runs live on your phone, alongside narrated stories from the Big Bang on and games built on gravity. Celestia also has an Android app for flying through a 3D model of space.

Can I simulate the Big Bang? Not from first principles; even research supercomputers start a little after it. The Story of Everything begins with First Light, about 13.8 billion years ago, when the young universe had cooled enough for light to travel freely, and follows the physics forward from there.

Is Everdust like Universe Sandbox? Partly. Both run gravity live. Universe Sandbox is a deep, paid sandbox on Steam where you build systems and change the rules; Everdust is a set of ready-made worlds, stories and games, free to start, on phones, a headset and the web.

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