Recursive Attenuating Amplification¶
Core Idea¶
A single one-shot input is recirculated through a system that retains a fixed sub-unit fraction k of the marginal flow each pass, producing a total response larger than the input but bounded by input · 1/(1 − k). It is the strictly contractive (k < 1) regime of recirculating gain — a convergent geometric series — distinct from continuous-source growth, compounding, and the unbounded k ≥ 1 regime.
How would you explain it like I'm…
Fading Echoes Add Up
The Bouncing Dollar
Bounded Geometric Buildup
Broad Use¶
- Macroeconomics: the fiscal multiplier — a one-shot injection re-spent at the marginal propensity to consume, with leakage to savings, taxes, imports.
- Room acoustics: Sabine reverberation — a clapped pulse retaining a fraction of energy per reflection.
- Optics: Fabry-Perot etalons and integrating spheres accumulating intensity through sub-unit reflections.
- Neural circuits: a transient input to a recurrent loop with synaptic gain below one, holding a working-memory trace.
- Heat transfer: radiative re-trapping in greenhouse models.
- Chemistry: sub-critical chain reactions.
- Marketing: gossip-protocol reach and sub-viral campaigns below the threshold.
Clarity¶
Separates four substrate-confused patterns ordinary language fuses — generic amplification, exponential growth, compounding, and bounded recursive response — and converts "feedback getting out of hand" into the precise question of where the single scalar k sits relative to one.
Manages Complexity¶
Compresses the multiplier, Sabine equation, etalon intensity, and sustain into one shape parameterized by two scalars (input and k), with a clean intervention space: raise k to increase the total, increase leakage to lower it, alter loop latency to reshape timing.
Abstract Reasoning¶
Yields portable inferences: boundedness is fragile near k = 1 (where 1/(1−k) explodes and grows sensitive to small gain changes); magnitude and timing are separable; and leakage is the cleanest lever on magnitude.
Knowledge Transfer¶
- Economics ↔ optics: the multiplier formula 1/(1 − k) is mathematically identical to the Fabry-Perot intensity formula at resonance, so an economist can reason about a laser cavity without the optical formalism.
- Acoustics ↔ neuroscience: the Sabine reverberation-time calculation transfers directly to neural-circuit decay under sub-unit recurrent gain.
- Non-transfer caveat: the closed form requires k constant across rounds; where retention varies, the clean sum breaks down — and knowing this is part of what transfers.
Example¶
A $100 fiscal injection is re-spent at a marginal propensity to consume of 0.8, adding $80, then $64, and so on — the convergent series $100(1 + 0.8 + 0.8² + …) = $500, bounded at five times the injection, with the leakage lever (raising taxes or import-share) the cleanest way to shrink the multiplier without touching the spend.
Relationships to Other Primes¶
Parents (1) — more general patterns this builds on
- Recursive Attenuating Amplification is a kind of, typical Amplification — The bounded contractive (k<1) regime of recirculating gain yielding the closed form input*1/(1-k). Dossier-flagged as the parent/peer question to settle at Phase C. amplification's defining external-power-source criterion is the wedge (this prime's gain comes from re-accumulation of the one-shot input, not a separate reservoir) — so the edge is typical/low, owner may keep free-standing.
Path to root: Recursive Attenuating Amplification → Amplification → Founder Effect → Path Dependence → Dependency
Not to Be Confused With¶
- Recursive Attenuating Amplification is not Amplification because generic amplification is any input-to-output gain with no boundedness guarantee, whereas this prime is the specific bounded gain from recirculating a one-shot input, with the exact form input·1/(1−k).
- Recursive Attenuating Amplification is not Feedback because feedback spans negative, oscillating, and runaway regimes, whereas this prime is the strictly contractive positive-feedback corner that sums to a convergent series.
- Recursive Attenuating Amplification is not Recurrence because recurrence is the bare skeleton of a state re-entering a rule, whereas this prime adds the constant sub-unit k and one-shot input that yield the 1/(1−k) law.