Scale of the universe: how big is everything?

How Big? is a free, interactive scale of the universe. Zoom from the Planck length, the smallest length in physics, through quarks, atoms, cells, ants, people, the Taj Mahal and Mount Everest, up to planets, stars, galaxies and the observable universe. It features 108 hand-drawn objects with their real sizes, a fact for each, and a comparison with everyday things.

The 20 chapters

1. The Planck Scale — Down here, space and time themselves may churn into a quantum foam. No experiment has come anywhere close to probing this deep — everything at this scale is pure theory.
2. Inside the Nucleus — Protons and neutrons are made of quarks, bound by the strong force — the most powerful force in nature, over a hundred times stronger than electromagnetism.
3. The Empty Atom — Between a nucleus and its electrons lies almost nothing. If you squeezed the empty space out of every human on Earth, all of us would fit inside a sugar cube.
4. Atoms & Molecules — Everything you've ever touched is built from about 90 natural kinds of atom, snapped together into molecules.
5. The Machinery of Life — Proteins, DNA and viruses work at this scale — machines so small that visible light is too coarse to see them clearly.
6. Under the Microscope — Cells and bacteria rule here. Your body is built from roughly 30 trillion cells — and carries about as many bacteria.
7. The Edge of Sight — Around a tenth of a millimetre, things finally become visible to the naked eye — just barely.
8. Small Wonders — Insects, coins and the tiniest birds. The scale of things you can hold between your fingers.
9. Human Scale — The world we live in: things we can lift, ride and walk beside.
10. Giants — The largest animals ever to live top out here — alongside trains, palms and the gateways we build.
11. Monuments — The tallest things humans have ever built. Even the Burj Khalifa is less than a kilometre high.
12. Landscapes — Clouds, mountains, ocean trenches and cities. Yet shrink Earth to the size of a billiard ball and it would be smoother than one.
13. Countries & Worlds — India alone is almost as wide as the Moon. Our whole planet is small enough to circle in a couple of long-haul flights.
14. Giant Planets — Gas giants dwarf the rocky worlds. Jupiter is so massive that it and the Sun orbit a point just outside the Sun's surface.
15. Stars — Stars come in a staggering range of sizes. Some giants could swallow hundreds of millions of Suns.
16. The Solar System — Our solar system is mostly empty space. Sunlight takes over four hours just to reach Neptune.
17. Between the Stars — Stars are scattered unimaginably thinly. Even the nearest one is about 100 million times farther away than the Moon.
18. Galaxies — Galaxies are islands of hundreds of billions of stars — and there may be hundreds of billions of galaxies out there.
19. Groups & Clusters — Gravity gathers galaxies into groups and clusters, bound together across millions of light-years.
20. The Cosmic Web — On the largest scales, galaxies trace a vast web of filaments around enormous empty voids. This is the biggest structure there is.

See all 108 things and their sizes · About How Big? · Privacy