Computation Model: Finite State Machine
All systems with computation model: finite-state-machine
Systems (14)
Biological brain
f(x) = general intelligence / perception, memory, reasoning, motor control
The human brain contains ~86 billion neurons connected by ~10¹⁵ synapses. Each neuron integrates thousands of synaptic inputs and fires a spike when its membrane potential crosses threshold — a leaky ...
Boson sampler
f(x) = sampling from the permanent of a unitary matrix (classically #P-hard)
Identical single photons enter an m-mode linear optical network (beam splitters and phase shifters implementing a unitary U). Detectors at the outputs sample from a distribution whose probabilities ar...
DNA computer (Adleman 1994)
f(x) = Hamiltonian path via strand hybridization
Leonard Adleman's 1994 demonstration solved the directed Hamiltonian path problem using DNA strand hybridization. Cities encoded as DNA sequences, flight connections as complementary strands. Massivel...
DishBrain (in-vitro neural culture)
f(x) = closed-loop sensorimotor control / game-playing (via biological learning)
~800,000 human iPSC-derived or mouse cortical neurons are plated onto a high-density multi-electrode array (HD-MEA). The DishBrain system (Kagan et al., 2022, Neuron) embeds the culture in a simulated...
Domino computer
f(x) = boolean logic (AND, OR, NOT)
Standing dominoes propagate a falling signal. Fan-outs split signals, and careful geometry implements AND and OR gates. Signal is one-shot — must reset by standing dominoes again. Speed: ~1 domino per...
Galton board (bean machine)
f(x) = Gaussian / binomial distribution
Balls dropped through a triangular array of pegs deflect left or right at each level. The distribution of balls in the output bins converges to a Gaussian as N→∞. Each peg is an independent Bernoulli ...
Hanging chain (catenary)
f(x) = hyperbolic cosine / thrust line
A chain suspended from two fixed points and left to hang under gravity settles into a curve that exactly realizes the hyperbolic cosine. Gaudí used physical catenaries (inverted) to design the arches ...
LEGO mechanical computer
f(x) = arbitrary digital logic / sequential game state
A fully mechanical computer built from LEGO Technic with no electronics. Binary memory is stored as lever positions on a rotating drum (rod logic); a read/write head flips levers to write bits and sen...
Physarum polycephalum (slime mold)
f(x) = Steiner tree / shortest transport network (approximate)
The plasmodial slime mold extends filaments toward nutrient sources and progressively reinforces paths that carry more flow, pruning inefficient routes. Toshiyuki Nakagaki showed it reproduces the Tok...
Pneumatic logic (Coanda-effect fluidics)
f(x) = boolean logic (AND, OR, NOT, NOR) via wall-attachment bistability
A jet of air entering a Y-shaped channel naturally attaches to one wall (the Coandă effect) and locks into that state by low-pressure recirculation. A small control jet on the opposite side provides e...
Quantum and quantum-inspired annealers
f(x) = Ising model energy minimization / QUBO optimization
Quantum and quantum-inspired systems for solving combinatorial optimization problems through annealing processes. Includes true quantum annealers (D-Wave) using superconducting qubits and quantum-insp...
Simulated annealing (thermal)
f(x) = argmin of energy / cost landscape
A physical system coupled to a heat bath at slowly decreasing temperature explores its energy landscape. At high temperature it escapes local minima; as T→0 it settles into a global minimum — if cooli...
Soap film
f(x) = minimal surface (Plateau's problem)
A soap film spanning a closed wire boundary settles into the surface of minimum area — the solution to Plateau's problem. For two parallel rings it realizes a catenoid. Can approximate Steiner trees f...
Thermodynamic computer
f(x) = sampling from Boltzmann distributions
Uses thermal noise in analog circuits to sample from Boltzmann distributions. Thermal fluctuations provide natural randomness that follows statistical mechanics principles. The Normal Computing SDE (S...