Determinism: Deterministic
All systems with determinism: deterministic
Systems (29)
Antikythera mechanism
f(x) = astronomical positions, eclipse prediction, Metonic calendar (multi-cycle gear ratios)
A hand-cranked bronze gearwork device built around 150–100 BC — the oldest known analog computer. Turning a single input crank advances 37 meshing gears whose tooth-count ratios encode the periods of ...
Billiard-ball computer
f(x) = reversible boolean logic (Fredkin gate)
Proposed by Fredkin & Toffoli (1982). Balls travel on paths representing wires; presence/absence of a ball encodes a bit. Collisions at path intersections implement logic gates. Logically and thermody...
Differential analyzer
f(x) = solutions to systems of ODEs (via chained mechanical integration)
Built by Vannevar Bush and Harold Hazen at MIT in 1928–1931, the differential analyzer is a general-purpose analog ODE solver. The core component is a wheel-and-disk integrator: a disk rotates at rate...
Diffractive deep neural network (D²NN)
f(x) = neural network inference / image classification (at the speed of light)
A stack of passive, 3D-printed diffraction layers implements a trained neural network entirely in the optical domain. Each layer is a mask with pixel-wise phase or amplitude modulation, trained offlin...
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...
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 ...
Kelvin tide-predicting machine
f(x) = sum of sinusoids / tidal height (Fourier synthesis)
Designed by Lord Kelvin (William Thomson) in 1872–73, this special-purpose mechanical analog computer performs real-time Fourier synthesis. Each tidal harmonic constituent (M2, S2, N2 …) is represente...
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...
Liquid marble computer
f(x) = boolean logic / reversible gates (AND, XOR, OR, NOT, Toffoli, Fredkin)
Liquid marbles are millimetre-scale droplets coated with hydrophobic powder that makes them roll freely without wetting surfaces. Computation is collision-based: two marbles directed at an intersectio...
MEMS accelerometer
f(x) = Newton's second law (a = F/m) — continuous analog acceleration measurement
A microfabricated proof mass (typically silicon, ~1 μg) suspended by folded-beam springs. Under acceleration, the mass displaces by x = ma/k (Hooke's law + Newton's second law in equilibrium). Displac...
MONIAC (Phillips hydraulic computer)
f(x) = Keynesian macroeconomic equilibrium (ODE system)
Built by Bill Phillips (1949). Water flows through tanks and pipes representing economic sectors — income, consumption, taxation, investment. Flow rates encode economic quantities. The system settles ...
Marble computer
f(x) = binary arithmetic / boolean logic
Gravity-fed marble runs with rocker/seesaw gates implement binary arithmetic and logic operations. One marble = 1 bit. The rocker flips state on each pass, implementing half-adders and logic gates. Th...
Mechanical fire-control computer
f(x) = ballistic trajectory / gun bearing and elevation (multivariate real-time ODE)
Electromechanical analog computers installed on WWII-era warships (e.g. the US Navy Mark 1) continuously computed the correct bearing and elevation for naval guns from up to 25 live inputs: target ran...
Mechanical gyroscope
f(x) = time-integral of angular velocity (orientation tracking)
A spinning rotor mounted in gimbals conserves angular momentum. Any external torque causes precession perpendicular to both the spin axis and the applied torque — rather than tilting directly. By read...
Memristor crossbar
f(x) = analog matrix-vector multiplication
Crossbar arrays of memristors (memory resistors) perform matrix-vector operations in analog. Voltages applied to rows, currents collected from columns. Resistance values encode matrix elements. Enable...
Op-amp analog computer
f(x) = ODE integration via Kirchhoff's laws
Operational amplifiers configured as integrators, adders, and multipliers solve differential equations in real-time. Voltages represent variables, circuit topology encodes the equation structure. Clas...
Optical correlator (4f / VanderLugt filter)
f(x) = cross-correlation / matched filtering (pattern detection in O(1) optical time)
A 4f lens system consists of two lenses separated by twice their focal length with a holographic or spatial-light-modulator (SLM) filter at the shared Fourier plane. The first lens computes the Fourie...
Photonic integrated circuit (silicon photonics)
f(x) = matrix-vector multiplication / unitary linear transforms (for neural network inference)
Arrays of Mach-Zehnder interferometers (MZIs) and microring resonators on a silicon chip implement programmable unitary matrices in the optical domain. Light encodes values as amplitude or phase; pass...
Planimeter
f(x) = area enclosed by an arbitrary plane curve (∮ via Green's theorem)
A two-bar linkage with a tracing point at one end and a measuring wheel mounted on the tracer arm. When the operator traces the boundary of an arbitrary shape, the wheel rolls only in the direction pe...
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 gate computer (superconducting qubits)
f(x) = unitary transformations / quantum algorithms
Superconducting qubits manipulated by microwave pulses to perform unitary operations. Quantum gates like Hadamard, CNOT, and phase gates enable quantum algorithms such as Shor's factoring and Grover's...
Reservoir computer
f(x) = temporal pattern recognition / dynamical system computation
Fixed nonlinear dynamical system (reservoir) coupled to a trained linear readout layer. Input drives the reservoir dynamics, output layer learns to extract desired computations. Echo state networks an...
Resistive sheet (Teledeltos) Laplace solver
f(x) = solutions to Laplace's equation ∇²φ = 0 (electrostatics, heat, groundwater flow)
A sheet of Teledeltos — carbon-coated resistive paper with ~6 kΩ/square resistivity — conducts current that obeys the same Laplace equation as electrostatic potential, steady-state heat conduction, in...
Rubber-band Steiner tree
f(x) = Euclidean Steiner minimum tree (approximate)
Elastic bands stretched between pins hammered into a board relax under tension to a state of minimum total length. Because each band pulls with a force proportional to its extension, the equilibrium c...
Slide rule
f(x) = logarithm, multiplication, division, roots
Logarithmic scales engraved on sliding rules allow multiplication by physical addition of lengths (log a + log b = log ab). Precision is bounded by engraving quality and human reading resolution — typ...
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...
Spaghetti sort
f(x) = total ordering of positive reals (sorting) in O(n) physical time
Cut n spaghetti strands to lengths proportional to the n values to be sorted. Gather them loosely in a fist and lower them vertically onto a flat table so all strands stand upright. Lower a flat hand ...
Water (fluidic) computer
f(x) = binary addition / boolean logic (AND, XOR)
Water levels in vessels encode binary digits; a siphon and slow drain combine to implement AND and XOR in a single cup-and-tube unit. A filled cup is a 1, an empty cup a 0. When two cups feed one cont...
Watt centrifugal governor
f(x) = proportional speed regulation (continuous set-point tracking via negative feedback)
Two steel balls are mounted on hinged arms linked to a rotating vertical shaft driven by the engine. As engine speed increases, centrifugal force swings the balls outward and upward; through a collar ...