3D simulation · Scale

The scale of the universe, in 3D

Name: How small are you?
Uploaded: 2026-11-05
Description: One zoom from an atom to a cell, a person, the Earth, the Sun, the galaxy and the whole observable universe.

One zoom from an atom to a cell, a person, the Earth, the Sun, the galaxy and the whole observable universe. Not a drawing and not an AI guess: a simulation that runs the real numbers, narrated, with every moment landing on its word.

Make this video →Free to try · 11 languages · about 3 minutes

What the simulation shows

Zoomed to an atom (a tenth of a billionth of a metre): its electron cloud.
Zoomed to a strand of DNA (2 nanometres wide).
Zoomed to a cell (a hundredth of a millimetre).
A person, about 1.7 metres.
Zoomed out to a whole city (about 15 km).
Zoomed out to the Earth (12,742 km).
Zoomed out to the Sun (109 Earths wide).
Zoomed out to the orbits of the solar system (9 billion km).
Zoomed out to the Milky Way (100,000 light-years).
Zoomed out to the observable universe: the cosmic web (93 billion light-years).

The real numbers it runs on

The simulation is built on these facts, so the narration and the picture always agree:

An atom is about a tenth of a billionth of a metre across; DNA is about 2 nanometres wide; a typical cell is about a hundredth of a millimetre.
A person is about 1.7 metres; a city about 15 kilometres; the Earth 12,742 km across.
The Sun is 109 times wider than the Earth (1.39 million km); the solar system to Neptune spans about 9 billion km.
The Milky Way is about 100,000 light-years across (a light-year is 9.46 trillion km) and holds 100 to 400 billion stars.
The observable universe is about 93 billion light-years across.
You are about as many times bigger than an atom (10 billion) as the Earth is bigger than you... roughly: we sit near the middle of the scales.

The script this video was made from

“How small are you?”: the narration of the video above. Each highlighted moment in the simulation happens on the word that names it.

This is you, about a metre and seventy. Now let's zoom out.

Home

Your city, fifteen kilometres. The Earth, twelve thousand seven hundred.

Out

The Sun, 109 Earths wide. Our galaxy, a hundred thousand light-years.

Everything

And all we can see: the observable universe, 93 billion light-years across.

Make your own

Type a question, like “How small are you?”, or your own angle on it.
ContentRoof picks this simulation, researches the facts and writes a short script, with every moment cued to a word.
A natural voice reads it in your language and the simulation plays in time with it. Change any line and it follows.
Download a vertical video for Shorts, TikTok and Reels, or use it in class.

Make this video →

Questions

Is this a real simulation or an AI-generated video?

A real simulation. The scale of the universe runs on the numbers listed above, so what you see is what actually happens, frame by frame. AI video generators guess what a scene should look like; they often get the science wrong.

Can I change what the narrator says?

Yes. Type your own question or idea and the AI writes a new script for this simulation, or edit any line yourself. Every moment of the simulation lands on the word that names it.

Which languages can it narrate in?

Eleven: English, Urdu, Hindi, Arabic, Spanish, French, Portuguese, German, Italian, Russian and Polish, with captions written properly (Urdu in Nastaliq, Arabic right to left).

Can I use it in class or post it on YouTube?

Yes. The video is yours to use in lessons, on YouTube Shorts, TikTok and Instagram Reels. The free plan makes 2 3D simulations a month; paid plans make more, in 1080p without the small mark.