OBSERVATION CHAMBER / ACTIVE

Nonequilibrium Markov Cycle Observatory

Change the transition rates of a three-state cycle. Observe probability flow, stationary circulation, cycle affinity, and entropy production.

structure / nonequilibrium cycle Observation Model

ROUTE 100 / STRUCTURE / MARKOV CYCLE

A steady distribution can still carry a current

Watch probabilities relax toward π. At nonzero affinity, the stationary distribution keeps a circulating current. Arrows show signed net probability currents, not particle trajectories.

PAUSED

Click a state to restart with 98% probability there and 1% in each other state. The buttons below do the same. Focus the canvas: Space/P = play or pause, S = step, R = reset.

TIME
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σ NOW
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σ AT π
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LOG RATE RATIO
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MASS DRIFT
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MAX |πQ|
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Probability ledger

Statep(t)πE

Rates and signed edge currents

Positive edgekᵢⱼ / s⁻¹kⱼᵢ / s⁻¹Jᵢⱼ / s⁻¹Jᵢⱼ(π) / s⁻¹

Positive orientation is 0 → 1 → 2 → 0. Negative J means reverse flow. In stationarity all three signed currents agree, although they need not be zero.

DETERMINISTIC CHECKS

Check conservation and limiting cases —

Checks cover stationarity, positive probabilities, mass conservation, composition, equilibrium, flat energies, current reversal and invalid input.

CheckErrorLimitResult

OBSERVATION GUIDE / STRUCTURE

Compare equilibrium and stationarity

  1. Choose EQUILIBRIUM and STATIONARY. Every edge current vanishes: detailed balance holds.
  2. Choose CLOCKWISE, then STATIONARY. π stays fixed while a current circulates. COUNTERCLOCKWISE reverses its sign.
  3. Choose FLAT. π is exactly one third in each state; J = (2/3)sinh(a/6) and stationary σ = aJ.

REPORT and PNG pause playback. Edits and reset clear stale outputs. Hidden tabs stop without catching up or restarting. Reduced motion disables playback, while STEP remains available. RESET restores a = 0, δ = 1, biased state 0, probability lens and empty checks and outputs.

Runs in this browser. No upload, registration or persistent storage.

MODEL AND SCOPE

Three positive states, continuous time

E = [0, δ, 2δ], k₀ = 1 s⁻¹
kᵢⱼ = k₀ exp((Eᵢ − Eⱼ)/2 + a/6)
kⱼᵢ = k₀ exp((Eⱼ − Eᵢ)/2 − a/6)
dpᵢ/dt = Σⱼ (pⱼkⱼᵢ − pᵢkᵢⱼ)
Jᵢⱼ = pᵢkᵢⱼ − pⱼkⱼᵢ
a = ln(k₀₁k₁₂k₂₀ / (k₁₀k₂₁k₀₂))
σ = Σ{01,12,20} Jᵢⱼ ln(pᵢkᵢⱼ / pⱼkⱼᵢ) ≥ 0

The rates above use the positive edges 01, 12 and 20. Each unordered pair enters σ once. E and a are dimensionless; entropy uses kB = 1 and σ is shown in kB/s. At a = 0, π is proportional to exp(−E).

Stationary probabilities use directed spanning trees. Uniformization evolves probabilities with P = I + Q/q and bounded Poisson tails. It preserves positivity without Euler clipping. This model does not simulate particle walks, eigenmodes or personal estimates. It does not measure heat, work, organisms or real networks.

OBSERVATION POLICY

This deterministic three-state continuous-time Markov model runs in your browser. Rates, calculations, reports, and images stay local. It does not sample particle paths or measure visitors or real systems.