Exploring Intelligence: The Matching Principle
One idea, carried from a 1928 antenna to a theory of mind. A wave meets a boundary and whatever does not match comes back — and that same geometry reappears as lost channel capacity, as a bandwidth budget you cannot overspend, as the heat of erasing a bit, as a robot's contact chattering against a wall, and finally as surprise. You start with no prerequisites and finish by writing one function that reproduces every answer you earned along the way. The Smith Chart Navigator and the passivity disk are your instruments throughout.
▶ Start the course ← All coursesFoundations: the wave, the bit, and the loop
Build the vocabulary from nothing: what reflects, what a bit is, and where an agent touches its world.
- L1Waves, reflection, and the scariest chart in engineeringMeet the founding image of the course: a wave hits a boundary, and whatever does not match comes back.→
- L1What is information?Put a number on surprise, so that later we can ask what a channel costs.→
- L1What is an agent?Draw the loop that makes something an agent, and find the one place it can touch its world.→
The universal matching principle
Show that one theorem sizes an antenna and a gearbox, and that impedance is a language, not a metaphor.
The information spine
Carry matching into information: the optimal receiver, and the conservation law that caps every match.
The physical price of a bit
Find where information finally touches thermodynamics, and what forgetting costs.
Physical AI: learning the interface
Follow the chart onto the die and into the model — and design a matching network with a net.
Embodied AI: contact and the body
Meet the disk again in mechanical dress: the passivity condition, and what a compliant body computes.
The unifying frontier
Reach surprise as the last reflected wave, and collapse the course into one function.
- L3The free energy principle: matching as cognitionReach the top of the ladder: surprise as the last reflected wave.→
- L3Curiosity: seeking the reflected waveTurn the free-energy agent active — make it seek the mismatch — and find exactly when curiosity buys speed and when it does not.→
- L3Development: the U-shaped curveWatch a learner *develop* — memorize, then over-generalize, then reconcile — the fingerprint that tells an entity apart from a controller.→
- L3Capstone: a theory of intelligence as matchingCollapse the whole course into a single function, and make it reproduce every answer you earned.→