---
slug: "Decay"
name: "Decay"
type: "Primitives"
layer: "Physics"
ref: "Decay#482b"
sema_id: "sema:Decay#mh:SHA-256:482b97f7196f35c8c50be1b2537ec6e04410a4920fcd8409bec735db3278737a"
tags: ["Physics","Primitives"]
updated: 2026-11-11
mindscape: "bootstrap"
index_url: https://mindscape.world/scapes/bootstrap.json
url: https://mindscape.world/bootstrap/Decay/
related: ["State","Value","Crystallize","CurriculumReplay","EpistemicCalibrate","ExpiringToken","GlacialVault","Resonate","Stigmergy","StateTransition"]
---

# Decay

Automatic expiration of stale state

Layer: Physics · Category: Primitives

## Mechanism

Gradual attenuation: without reinforcement, [Value](https://mindscape.world/scapes/bootstrap/Value.md) V decreases over time. `half_life` determines the rate. Reinforcement resets or boosts V. V descends to `floor_value` and stops there; reaching the floor triggers a [State](https://mindscape.world/scapes/bootstrap/State.md) change, and removal only where the floor is zero.

## Invariants

- Monotone absent reinforcement: V does not increase unless reinforced.
- V never descends below `floor_value`.

## Failure modes

- Unreachable removal: `floor_value` is above zero, so V never reaches zero and a removal trigger set at zero never fires.

## Parameters

- `floor_value` (Float, [0.0, 0.5]): Minimum value, never decays below
- `half_life` (Duration, [1min, 30d]): Time for value to halve

## Builds on

- [State](https://mindscape.world/scapes/bootstrap/State.md) (Infrastructure; References)
- [Value](https://mindscape.world/scapes/bootstrap/Value.md) (Infrastructure; References)

## Used by

- [Crystallize](https://mindscape.world/scapes/bootstrap/Crystallize.md) (Mind; References)
- [CurriculumReplay](https://mindscape.world/scapes/bootstrap/CurriculumReplay.md) (Mind; References)
- [EpistemicCalibrate](https://mindscape.world/scapes/bootstrap/EpistemicCalibrate.md) (Mind; References)
- [ExpiringToken](https://mindscape.world/scapes/bootstrap/ExpiringToken.md) (Society; References)
- [GlacialVault](https://mindscape.world/scapes/bootstrap/GlacialVault.md) (Society; References)
- [Resonate](https://mindscape.world/scapes/bootstrap/Resonate.md) (Society; References)
- [Stigmergy](https://mindscape.world/scapes/bootstrap/Stigmergy.md) (Society; References)

## Identity

- Sema ID: `sema:Decay#mh:SHA-256:482b97f7196f35c8c50be1b2537ec6e04410a4920fcd8409bec735db3278737a`
- Ref: `Decay#482b`
- Supersedes:
  - `sema:Decay#mh:SHA-256:a1d4b9d5a517a5a8e942a9bedaafdd004b3d7d5bf2e02bd4018af16350bb64f0`
  - `sema:Decay#mh:SHA-256:ed25c7d3a502881dbdd455802f3c1d3581c2514f263d5339bc4e56221416b552`

## Links

- [Pattern page](https://mindscape.world/bootstrap/Decay/)
- [View in the interactive graph](https://mindscape.world/bootstrap/#Decay)
- [JSON](https://mindscape.world/scapes/bootstrap/Decay.json)
- [Index of all patterns](https://mindscape.world/scapes/bootstrap.json)