OBSERVATION CHAMBER / ACTIVE

Graph Spectral Diffusion Field

Observe heat diffusion on a weighted graph through Laplacian eigenmodes, spectral gap, heat trace, and community mixing.

structure / graph diffusion Observation Model

ROUTE 69 / STRUCTURE / GRAPH DIFFUSION

LAPLACIAN / HEAT EQUATION

A graph signal settling through its eigenmodes

Read the same weighted graph as topology, spectrum, and heat flow. The canvas shows values on vertices; the readouts keep the numerical contract in view.

PAUSED

Each vertex stores u. Edge brightness follows |uᵢ − uⱼ|; the lower bars show λ in ascending order. Select a vertex with pointer or touch.

All calculations stay local in this browser.

Vertices
Edges
λ₀
λ₁ / gap
Heat trace
Mass Σu
Energy uᵀLu
Components / zero

SPECTRAL READOUT

What the graph is conserving

PASS
λ₀ / zero mode
λ₁ / spectral gap
Zero multiplicity / components
Heat trace Tr(e⁻ᵗᴸ)
Mass Σu
Dirichlet energy
Community contrast
Selected vertex
Solver
FINITE · Jacobi rotations

For bridge OFF, λ₁≈0 and the zero multiplicity is two. Bridge ON makes the graph connected, so λ₁ becomes positive.

DETERMINISTIC SELF-TEST

Numerical acceptance

PASS

BRIDGE OFF / PASS

CHECKVALUELIMITRESULT
Observation report

OBSERVATION CONTRACT

Graph heat, not particle motion

The field is a scalar value on vertices. L = D − A is built from the weighted adjacency matrix, and u(t) = exp(−tL)u₀ is evaluated in the symmetric eigenbasis. No walkers, membrane vibration, clock synchronization, or network animation is used.

WHAT TO WATCH

Gap, trace, and mixing

  • BRIDGE OFF gives two connected components and two zero modes.
  • BRIDGE ON gives one component and a positive λ₁.
  • Heat trace falls with time; total mass is conserved; Dirichlet energy does not increase.

MODEL NOTE

Symmetric graph Laplacian

L = D − A, L1 = 0, Lvₖ = λₖvₖ

The graph has at most 24 vertices. The solver is a deterministic Jacobi decomposition with residual and orthogonality checks.

Formula note

du/dt = −Lu and u(t) = Σₖ e⁻ᵗλₖ (vₖᵀu₀)vₖ. The heat trace is Tr(e⁻ᵗᴸ) = Σₖe⁻ᵗλₖ; the Dirichlet energy is uᵀLu = Σ_(i,j) wᵢⱼ(uᵢ−uⱼ)².

OBSERVATION GUIDE

Touchpoints for observation

Start with TWO COMMUNITIES and BRIDGE OFF. Select FIELD, then STEP. The contrast signal fades inside each component while the zero modes stay visible.

  • Switch BRIDGE ON and STEP again. The graph becomes connected and λ₁ opens.
  • Use MODE 1 or MODE 2 to inspect eigenvectors instead of the evolving field.
  • Use pointer, touch, or arrow keys to choose a vertex. Reduced-motion stops PLAY and keeps STEP available.

This is a finite weighted-graph heat model, not a particle simulation, a physical heat measurement, or a full-scale network solver.

Runs inside the browser with no upload and no registration.

OBSERVATION POLICY

This chamber runs a deterministic weighted-graph heat model in your browser. The graph, calculations, reports, and images stay local. It does not measure visitors, devices, social networks, or physical heat.