About How Big?

How Big? is a free, interactive journey through scale. Zoom from the smallest length in physics, past atoms, cells, auto rickshaws, Qutub Minar and the Taj Mahal, out to planets, stars, galaxies and the edge of the observable universe.

How to explore

• Zoom with your mouse wheel or trackpad, by pinching on a phone, or by dragging up and down.
• Travel fast by dragging the ruler at the bottom of the screen, or with the − and + buttons.
• Jump to anything by tapping it. Each thing has its size, a fact, and an everyday comparison.
• Music: turn on the calm ambient soundtrack with the speaker button, or press M.
• Share: the share button creates a link that opens straight at whatever you're looking at.

About the sizes

Every size is a rounded, typical value — real cats, cells and clouds vary. For living things we use typical adult sizes; for buildings, their height; for vehicles, their length; and for planets and stars, their diameter. Distances, like Earth to the Moon, are drawn as measured lines.

Sources

Values come from widely published reference figures, including NIST/CODATA physical constants for atomic and subatomic scales and NASA's planetary fact sheets for the Solar System. If you spot something that looks wrong, please get in touch and we'll fix it.

How it's made

Every illustration is drawn in code with a hand-sketched ink style, and the music is generated live in your browser — there are no image or audio files to download, so it stays fast even on slow connections.

Contact

Questions, corrections or ideas for new things to add: steve.marcus2011@gmail.com