The whole story, told without a single equation. What we built, the strange force we found, how it passed the apple test — and the beautiful ideas we had to bury on the way. If you've never opened a physics book, this page is for you.
We build tiny toy universes inside a computer. Not pictures of universes — working ones: a small patch of "vacuum" where every ripple and every jiggle is computed exactly, with nothing hidden and nothing approximated away. Toy universes are small and humble, but they have one superpower: you can ask them questions and they cannot lie.
The question we asked this week is very old. It is the most embarrassing question in physics, and it fits in four words: what makes things fall? Newton told us how they fall — perfectly, 340 years ago. Einstein told us how they fall near black holes — perfectly, 110 years ago. Neither theory says what gravity actually is. There is no mechanism inside. It is a perfect machine with no gears.
In 1748, a schoolmaster in Geneva named Georges-Louis Le Sage proposed the only mechanical explanation of gravity anyone has ever offered. Imagine space filled with an invisible hail falling from every direction. Objects block a little of it. Two objects shade each other — and the hail, pushing on every side except the shaded one, presses them together. Gravity as a shadow.
It's lovely, and it's wrong, and the way it's wrong matters. James Clerk Maxwell showed that if the hail bounces off things elastically, every shadow gets refilled exactly — the bounced hail pays back what the shadow took, to the last penny. The force vanishes. The books always balance. For 150 years, that refund killed every shadow theory of gravity. Case closed.
Except Maxwell's proof has a hidden assumption: it works in a medium where waves pass through each other like ghosts, never interacting. Real media aren't like that. Nobody had ever checked what happens to the refund when the medium itself reacts. So we did.
Here is our experiment, as a story you can picture.
A calm pond. Plant a post in the bottom, and make it tremble randomly — that's our "watched" object. (In quantum physics, being observed is not a gentle thing: whatever measures you also jiggles you. A watched object is a jiggled object, always.) The trembling post sends messy little ripples in every direction.
Now float a cork two meters away. In an ordinary pond, the ripples hit the cork and slowly push it away. Nothing exotic — waves push. We measured exactly that.
But now try a pond whose water changes where it's agitated — say it thickens where things shake it, like water full of starch. Something entirely different happens: the cork drifts toward the post. The thing that trembles, attracts. We measured that too — and then we spent two days finding out exactly why.
Here is the "why", and it's our favorite thing we've ever found.
When the post's ripples reach the cork, some bounce back. Incoming and bounced ripples overlap on the cork's front side and make a bright patch of agitation there — and a quiet shadow behind. In ordinary water this bright patch just pushes the cork away. Maxwell wins, as always.
But the starchy water does something the ordinary pond can't: it takes a photograph. It thickens exactly where the bright patch is. And here's the twist: thickened water is stiffer, and stiffer water trembles less on its own. The thickening ends up calming that spot more than the ripples were brightening it. The photograph develops as a negative: the bright patch becomes the quietest place around.
This is not just a pretty story — we checked each step separately in the toy universe. The bright patch is there (we measured it). The photograph is there (we measured the thickening). The negative is there (the bright spot really does become the quietest, by a lot). And a pencil-and-paper calculation now predicts where the switch from push to pull happens — and it matches.
A cute force in a toy pond is one thing. Newton's gravity is another: it has a very particular signature. Double the distance between two objects, and the force drops to a quarter. Triple it, and it drops to a ninth. One over distance-squared — the law of the apple, the Moon, and everything else.
Why that particular law? Picture butter and toast. A source sends out its influence like a fixed amount of butter, spread each second over a sphere that grows with distance. A sphere twice as big has four times the surface. Same butter, four times the toast: a quarter of the butter per bite. That's all 1/distance² means — the influence is a real flux, spreading out and getting diluted.
And here's the beautiful part: that dilution law changes with the shape of the world. In a one-dimensional world — a wire — there's nowhere to spread: the force shouldn't weaken with distance at all. In a flat, two-dimensional world it should weaken like 1/distance. Only in a three-dimensional world like ours does it go as 1/distance². So we built all three worlds and measured:
We are not saying we found what gravity is. Honesty is the whole point of this project, so here is the other side of the ledger, with no small print:
Fourteen of our own ideas are buried on this site, each with its tombstone visible. That's not a failure of the project — that is the project. A theory that never loses an argument with reality isn't strong; it's unexamined.
Remember the pond. In a medium that reacts to agitation, being watched creates weight: whatever is observed gets jiggled, whatever is jiggled prints a hollow into the world around it, and everything nearby falls toward the hollow — exactly as hard as Newton says it should, fading with distance exactly as Newton says it should.
Whether the real vacuum is that kind of pond is the open question — the one experiments in the 2030s may actually answer. We don't know. Nobody knows. But for the first time in a long time, the oldest question in physics — what makes things fall? — has a possible answer you can picture with your eyes closed: the universe watches, and what it watches, it holds.
Every number behind this story comes from a short program you can run on an ordinary laptop in minutes. They're all free, on this site, with the failed attempts left in. The technical page has the full account with every claim tagged by how sure we are — and every tombstone.