Anatomy.
Take one machine and cut it into three: the body it is made of, the one rule that runs it, and the learned brain that decides. Every lesson refuses you its answer until you guess, then proves it in front of you — real physics, real policies, every number on the board computed by an open core, so the page cannot lie. Six machines run this way now: fly, balance, grasp, drive, grip soft, and swim — across every medium and mode a body can meet the world.
Six ways to meet the world.
A drone, a humanoid, a hand, a rover, a soft hand — and a fish that moves through water, the third medium after air and ground. Nothing about them is alike except the method that takes each one apart, and the fact that each stays useful for a completely different reason. Start anywhere; the layers rhyme across all six.
Anatomy of Flight
Stays up by pushing air down.
One eVTOL, taken apart three ways — the body it is made of, the loop that flies it, and the brain that decides where to push. The surprising body number is endurance, not thrust; the control rule is that it must lean to move; the brain is a real policy flying the airframe live and recovering a shove.
Open the demonstration →Anatomy of Balance
Stays up by not falling over.
One printed humanoid — the body that stands for almost no power, the capture-point loop that catches a shove by stepping to a spot it can name, and the brain that runs the ankle a hundred times a second. Standing is nearly free; the step is computed before the foot lands.
Open the demonstration →Anatomy of Grasp
Holds by geometry, not by force.
One hand — the fingers that hold with almost no squeeze, the force-closure rule that decides whether a grip catches or spins free, and the brain that scores candidate grasps and picks the best. The one regime the drone and humanoid never touch: seizing the world and not letting go.
Open the demonstration →Anatomy of Driving
Rolls for free, but never sideways.
One rover — the wheels that carry it kilometres on the charge that only hovered the drone, the nonholonomic rule that forbids it from sliding straight left, and the brain that turns a parking spot into steering and throttle. The cheapest way to move, bought with a constraint on where it can go.
Open the demonstration →Anatomy of the Soft Hand
The body does the thinking.
One compliant hand — twelve joints closed by a single motor, a body that fits any shape on its own (morphological computation), and the smallest brain in the series because the mechanics already did the work. The only soft machine, and the deepest idea: the body as controller.
Open the demonstration →Anatomy of Swimming
Held up for free, fought harder for speed.
One robotic fish — a buoyant body that holds its depth for nothing, the quadratic-drag rule that means twice the push buys only √2 the speed, and a brain that learned to invert that rule and set the pace. The third medium a body moves through: water.
Open the demonstration →Every one is a body, a rule, and a small brain.
Read across the six and the same three layers appear every time — the physics of the body, one rule that governs it, and a learned brain to decide. And look at the last column: the largest brain in the series is 843 numbers, the smallest is 97. That is the quiet thesis of the whole set — intelligence for the physical world is small and cheap when a real body and its one rule already do most of the work.
| Machine | The body — what surprises you | The one rule | Brain |
|---|---|---|---|
| Flight | Eleven minutes of hover — bound by energy, not thrust | It must lean before it can move | 843 |
| Balance | Standing costs almost no power at all | Step to the capture point, ξ = x + v∕ω | 337 |
| Grasp | About ten newtons — friction sets it, not the motor | Force closure: it holds iff Q > 0 | 369 |
| Driving | Fifty kilometres on the battery that only hovered | A wheel rolls, but never sideways | 746 |
| Soft Hand | One motor drives all twelve joints | The body conforms to the shape on its own | 97 |
| Swimming | It holds its depth for no power at all | Double the push, only √2 the speed | 141 |
None of these brains is bigger than a small spreadsheet — and each one flies, stands, grips, parks, wraps or swims a real body, live, on the page. That is the reach of Physical AI: not a larger model, but the right body under a smaller one.
One engine, six machines.
Every Anatomy runs on the same small engine: the same withhold-guess-prove beat, the same editable source sitting beside the board, the same rule that nothing on the board is animated by hand. Change the source and the physics recomputes; press the wrong beat and nothing lies to you. Carrying the format from a flying machine to a walking one to a grasping one to a rolling one to a soft one to a swimming one took a single generalization, which is the whole argument that it is a format and not a trick.
Guess first
Each demonstration opens with a question almost everyone gets wrong and refuses to answer it until you commit. Withholding is the engine of attention — the same predict-first beat now offered in every Institute course.
It cannot lie
Endurance, capture point, force closure, the nonholonomic constraint, morphological computation — six learned policies flying, standing, gripping, parking, conforming and swimming — each is checked live by an open core, on the production page. Verified, not asserted.
Body to brain
Every machine carries the whole stack: the physics of the body, the one loop that runs it, and the learned policy that decides. Six times over, the three layers of an embodied system, in one place you can turn over in your hands.