Reusable cognitive primitives
Diffusion & spread
Countless small random steps carry things from where they are crowded to where they are sparse — smoothing differences and spreading through a network.
Where it appears
Dependencies & synergies
Derived from the graph’s real structure — 5 concepts across 14 disciplines carry this pattern. Every figure is a count, not a score.
How many concepts carrying this pattern are seen through each discipline.
Other thinking patterns that recur on the same concepts — the more shared concepts, the more often they co-occur.
What kinds of relationships the carrying concepts form — the relational signature of the pattern.
Concepts where this pattern does the most cross-disciplinary work — each reaches disciplines beyond its own.
- Epidemic spreadreachesAlgebraAnthropologyBiologyBiophysicsChemistryDiscrete MathematicsEconomicsEnvironmental EngineeringEnvironmental ScienceEthicsFinanceLinear AlgebraMathematicsMedicinePhysicsPhysiologyPublic PolicySociologyStatistical PhysicsStatisticsUrban Planning
- DiffusionreachesBiologyCell BiologyEngineeringEpidemiologyNetwork ScienceNutrition SciencePhysiologyPublic Health
- Gas exchangereachesBiophysicsChemistryEnvironmental EngineeringEnvironmental SciencePhysicsSociologyStatistical Physics
- OsmosisreachesChemistryEnvironmental EngineeringEnvironmental SciencePhysicsSociologyStatistical Physics
- Thermal conductionreachesChemical Engineering
Examples across disciplines
A scent spreads across a room by molecular diffusion.
An epidemic spreads through a contact network.
A new technology diffuses through adopters over time.
How this pattern travels
Interpreted from where the pattern recurs in the atlas — structural transfer and coverage, not a claim it is universally the "best" model.
Recurs across 14 disciplines over 5 carrier concepts — a broadly transferable pattern.
structural · Structural recurrence in the atlas — a pattern is a reasoning lens, not a law.
3 of its 5 carrier concepts are themselves cross-disciplinary connectors.
structural · Structural recurrence in the atlas — a pattern is a reasoning lens, not a law.
Explicit "where it breaks" notes exist for 5 of 5 annotated assignments.
curated · Curated boundary annotations — absence is a representation gap, not evidence the model has no limits.
Currently dark in the atlas: no origin recorded.
atlas representation · Describes the current Thinking OS representation, not the model itself.
Coverage matrix
How these concepts distribute across domains and concept families — real counts, not a score.
The statistical fingerprint
How the 5 concepts that exercise this pattern distribute — from the graph, not a ranking.
Disciplinary fingerprint
Carrier concepts under each illuminating lens.
How settled its carriers are
Epistemic status of the concepts that exercise this pattern.
Where the model breaks
This pattern is a reasoning lens, not a law. Here is where it stops helping:
- Diffusion (mechanism): Explains passive spreading down a concentration gradient only — it does NOT cover bulk flow (advection), active transport, or contact/network spread.
- Epidemic spread (analogy): Diffusion assumes local, gradient-driven spread; real epidemics also jump non-locally through travel and contact networks, which pure diffusion cannot capture.
- Gas exchange (mechanism): Diffusion sets the local step, but effective exchange depends on bulk ventilation and perfusion delivering the gradient — diffusion alone is too slow over distance.
- Osmosis (mechanism): Osmosis is diffusion of solvent across a selective membrane driven by water potential; treat it as free diffusion of solute and you get the direction wrong.
- Thermal conduction (mechanism): The diffusion analogy fits conduction, but convection and radiation often dominate heat transport — using diffusion everywhere underestimates the real flux.
5 of 5 explained assignments cite a source; the rest are editorial interpretations. 1 are flagged for review. None is externally validated.
✕ Something must be pushing it in a direction. Pure diffusion needs no push — random motion plus a gradient is enough.
You have seen this model in one place. Where else could it apply — and where would the analogy break?
Gas exchange →Expect spread to be driven by a gradient and by contact. Early growth can look explosive, then slows as the gradient flattens or susceptibles run out.
- Recurs across 14 disciplines.
- 17 concepts exercise this thinking pattern.
- 5 of them explicitly note where the model breaks down.
Derived from the graph — a pattern is a reasoning lens, not a law.
Is there a gradient from crowded to sparse, and does the spread happen through contact — fast at first, then slowing as the gradient flattens?
Keep this question handy when you meet something new — it helps you notice the pattern, not just name it.