From quarks to the cosmic web
Drag the slider across 45 orders of magnitude
The universe operates on scales so extreme that our evolved primate brains physically cannot comprehend them. Here's an attempt anyway.
The observable universe spans 93 billion light-years — and it's still expanding faster than light itself at its edges.
There are over 2 trillion galaxies in the observable universe. Each one contains billions of stars. Most of them, we'll never see.
Roughly a septillion stars. That's more stars than grains of sand on every beach on Earth — by a factor of ten.
Atoms are 99.9% empty. If a hydrogen atom were a cathedral, its nucleus would be a grain of salt at the center.
The universe has been expanding for 13.8 billion years. Humans have existed for 0.001% of that time.
The full universe may be 250× larger than what we can see — or it might be literally infinite. We don't know. We may never know.
Click a star to learn more — sizes are to relative scale
If Earth → Moon is 1 pixel wide...
Galaxies come in wildly different forms
The honest terrifying stuff
Something with mass is holding galaxies together, but we can't see it, touch it, or detect it directly. We only know it's there because without it, galaxies would fly apart. After decades of searching, we still have zero confirmed detections.
The universe isn't just expanding — it's accelerating. Something is pushing space apart faster and faster, and we've named it "dark energy" mostly as a placeholder for "we have absolutely no idea." It makes up most of the universe.
Light from beyond ~46.5 billion light-years away hasn't had time to reach us. There could be infinite more universe, copies of you, or something so alien our physics can't describe it. The edge isn't a wall — it's a horizon of ignorance.
Our entire local supercluster — hundreds of thousands of galaxies — is being pulled toward a point in space we can't properly see because our own Milky Way is in the way. Something with the mass of a million billion suns is pulling us at 600 km/s. We don't know what it is.
Galaxies aren't scattered randomly — they're strung along enormous filaments of dark matter, forming a web-like structure. Between the filaments are colossal voids millions of light-years across containing almost nothing. The Boötes Void alone is 330 million light-years of near-emptiness.