From the smallest particles to the edge of the observable universe — one continuous journey through size, time and light.
Every photon reaching your eye tonight left its star long before cities existed. Cosmic Scale AI exists to make those distances feel real — to turn abstract numbers into something you can sense, question, and explore.
A middle-aged G-type star holding 99.86% of the Solar System's mass. Every second it fuses 600 million tonnes of hydrogen into light.
Ask anything about space, time, and the mysteries beyond.
Answers by Cloudflare Workers AI · fact-checked by you, the explorer
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Time elapsed since the Big Bang — measured from the oldest light we can detect.
The sphere of everything whose light has had time to reach us.
Each one averaging hundreds of billions of stars. Ours is ordinary.
Five questions at the edge of human knowledge. Select one — the void responds.
NASA · Hubble Space Telescope Archive
Write a note, pick any destination in the cosmos, and watch it race away at the speed of light — then turn it into a shareable cosmic card.
Open Call the StarsFinal Transmission
Explore cosmic mysteries. Ask impossible questions.
Discover your place in the universe.
Cosmic Scale AI is a website about how big space actually is — and why that's so hard to picture. Most of us know the universe is large. Far fewer of us have any real feel for what "large" means once you leave Earth. Closing that gap is the whole reason Cosmic Scale AI exists.
The trouble with astronomy is that the numbers outrun the imagination. "93 billion light-years" is just sound after a while. Cosmic Scale AI takes a different route: it shows you the jump instead of quoting the total. You start at one person and move outward — Moon, Earth, Sun, Solar System, galaxy, and finally the whole observable universe — and at each step the next thing sits right next to the last, so you can compare them directly.
It's interactive. Tap any object and you get the real measurement: diameter, distance, and how many times larger it is than whatever came before. The Sun is about 109 Earths across. The Milky Way runs roughly 100,000 light-years wide and holds something like 200 billion stars — most of them bigger than ours. None of this is made up; the figures come from standard observational astronomy, and the ones we're less certain about are marked as estimates.
Here's what that walk looks like in practice. You begin with a human, about 1.7 meters tall. Beside the Moon — 3,474 km across — you've already disappeared. Earth is 12,742 km wide and makes the Moon look small. The Sun is 1.39 million km across and could swallow roughly 1.3 million Earths. The Solar System stretches about 9 billion km out to Neptune. The Milky Way is 100,000 light-years across. And the observable universe, the slice of space whose light has had time to reach us, is about 93 billion light-years wide. Each step is shown against the last, so the size isn't claimed — it's seen.
The point isn't the trivia. It's that after a few scrolls, "the universe is big" stops being something you nod at and starts being something you can almost picture — the kind of feeling a textbook rarely manages to deliver.
You don't need a science background to use it. There are no equations to solve and no jargon for its own sake. When a technical word does show up, the text around it explains it in plain language. Cosmic Scale AI was made so a curious twelve-year-old and a tired adult at 1 a.m. get the same thing out of it: a clearer picture, not a lecture.
The scale tool is the backbone, but once you've scrolled to the edge there's more to do:
• Hubble Birthday — type in your birth date and it pulls the actual Hubble Space Telescope image taken that day. You can save it as a little card.
• Sky Engine — pick any city and any date from AD 1 to AD 9999 and see the true night sky above you, computed live with real star positions and precession.
• Time Machine — drag from the Big Bang to right now and watch how the sky has changed across 13.8 billion years.
• Call the Stars — write a message, pick a destination, and watch it travel at the speed of light, ticking off the years as it goes.
• The Gravity Simulator shows what you'd weigh on Jupiter or a neutron star, and the Astrobiology Simulation Engine guesses where life might survive beyond Earth.
One rule runs through all of it. Real science is labeled real, and anything simulated is labeled simulated. There's no bait-and-switch between fact and fiction, because Cosmic Scale AI is meant to be something you can trust.
We'd rather say "we don't know yet" than dress a guess up as fact. Space is mostly unknown, and the site is comfortable admitting it — which, oddly, is exactly what makes it feel worth trusting.
There's a box where you can type anything — "why is space dark at night?", "what's inside a black hole?", "are we alone?" — and get a plain-language answer drawn from actual astronomy. When the live AI isn't available, it falls back to a stored archive, and it tells you that's what happened. No pretending it's something it isn't.
The questions people actually ask are usually the big, slightly embarrassing ones — what happens if you fall into a black hole, whether time travel is real, if the universe has an edge. Cosmic Scale AI answers those straight, points to the parts we're sure of, and flags the parts we aren't.
Honest answer: the universe is the one thing we're all standing inside of, and almost none of us have a feel for it. School hands you the facts and moves on. This hands you the feel, which tends to stick longer. When the scale shows that sunlight takes eight minutes to arrive but light from the next star takes more than four years, "far away" stops being a word and becomes a distance you can almost sense. That's the whole reason Cosmic Scale AI was built — not to impress you, but to make the size of things finally add up.
Teachers use it to make "the solar system" click for a room of kids. Parents use it on a slow afternoon. I've watched people spend twenty quiet minutes just scrolling the scale, which is probably the best review the site could ask for. It runs in any browser, on a phone or a laptop, with nothing to install and no account to make.
There's no correct door. Open the scale. Ask a question. Find the Hubble photo from your birthday. Solve today's mystery. However you come in, Cosmic Scale AI is the same thing every time: real numbers, plain words, no agenda. Just the universe, rescaled so your brain can actually hold it.
You'll likely leave with one fact stuck in your head that you didn't have before. That, more than any number, is the point.
People ask a lot of questions about the scale of the universe, how space works, and the AI industry around it. Here are straight, sourced answers — no hype.
As of August 2026, the CEO of Scale AI is Francis deSouza, who took over on August 10, 2026 after being appointed by the board in late July. He is a veteran enterprise technology executive, formerly COO of Google Cloud and CEO of Illumina. Scale AI was founded in 2016 by Alexandr Wang, who left in 2025 to become Chief AI Officer at Meta; Jason Droege served as interim CEO in between.
NASA does not use a single AI. It builds and runs many. The agency develops its own models, such as the Prithvi geospatial foundation model built with IBM, and uses machine learning for rover autonomy, exoplanet searches, and weather forecasting. On the engineering side, NASA's Science Cloud gives researchers access to commercial tools like Microsoft's GitHub Copilot. The constant is that NASA applies AI where it clearly helps missions, under a strict responsible AI policy.
Scale AI has taken steps toward going public. It filed a confidential S-1 in early 2026, but as of August 2026 it remains a private company and has not yet listed. Reporting at the time pointed to a possible debut later in 2026, though no date was confirmed. Until shares actually trade on an exchange, there is no public stock to buy.
Yes. Scale AI is one of the most important companies in the AI infrastructure layer. It supplies training data and evaluation tools to major AI labs such as OpenAI, Anthropic, and Google, and to government customers including the U.S. Department of Defense. After Meta invested roughly 14 billion dollars for a stake in 2025, its valuation sat around 25 to 30 billion dollars, with staff across data, applications, and research.
That depends on how you count, but Elon Musk is most often named the richest person whose fortune is tied to AI. In 2026 his net worth was estimated at more than 800 billion dollars, driven by Tesla's self driving efforts, SpaceX, and his AI venture xAI, maker of Grok. Other AI linked billionaires near the top include Larry Page, Sergey Brin, Larry Ellison, and Nvidia's Jensen Huang.
Here is the surprise: the stuff we can actually see, stars, planets, gas, and us, is a tiny sliver. Ordinary matter, the atoms we are made of, makes up only about 5 percent of the universe's mass energy, and visible stars are less than 1 percent of that. The rest is dark matter, about 27 percent, and dark energy, about 68 percent, which we cannot see directly. So 1 percent is roughly the share of the cosmos made of the bright, familiar matter we call home.
Essentially, yes. About 95 percent of the universe is made of dark matter and dark energy, things we detect only through their effects on gravity and the expansion of space, never directly. Only the remaining 5 percent is ordinary matter, and most of even that is dim gas and dust rather than shining stars. Hidden is a fair word, though scientists prefer not yet directly observed.
Because the universe has been expanding while the light traveled to us. The universe is 13.8 billion years old, so the oldest light has been on the move that long, but space itself stretched in the meantime, carrying the sources to about 46 billion light years away. That is the radius of the observable universe: 13.8 billion years of travel time, wrapped in 46 billion light years of expanded space.
In astronomy, cosmic simply means relating to the universe, its origin, structure, scale, and evolution. A cosmic concept is any big picture idea about how the universe works, from the Big Bang and cosmic expansion to the life cycles of stars. On this site the core cosmic concept is scale: understanding where we sit in a universe that spans from a single proton to 93 billion light years.
Outside science, cosmic often carries a feeling of vastness and connection, the sense that we are part of something far larger than ourselves. Many spiritual traditions use cosmic imagery, the star stuff we are made of, the unity of all things, to express awe and belonging. It is a poetic cousin of the scientific meaning, and both point to the same humbling idea: we are small, and somehow, made of the universe itself.