{
  "id": "cusp.threshold",
  "term": "cusp",
  "sense": "threshold",
  "pos": "noun",
  "status": "review",
  "level": 14,
  "arena": "ontological",
  "domain": "window",
  "style": "window",
  "definition": "a parameter whose window overlaps with another, where the crossing leads into the second rather than ending the first",
  "folk_gloss": null,
  "emergence": {
    "components": [
      "parameter.condition",
      "window.range",
      "wall.range-end",
      "drift.aimless",
      "cross.symbol",
      "first.order",
      "lead.guide",
      "rather.comparative",
      "second.temporal"
    ],
    "interaction": "The drift of a parameter toward a wall of its window coincides with the opening of an adjacent window, and the crossing of the boundary leads into the second state rather than terminating the first.",
    "novel_properties": [
      "transition priority",
      "asymmetric window crossing",
      "concurrent persistence and change"
    ]
  },
  "examples": [
    {
      "text": "In 2007, the Arctic sea ice extent dropped below 4.2 million km², crossing a threshold scientists now associate with irreversible summer melt trends.",
      "domain": "climate"
    },
    {
      "text": "The Therac-25 radiation therapy machine allowed parameter drift in beam intensity until a software threshold was crossed, delivering lethal doses.",
      "domain": "engineering"
    },
    {
      "text": "Bitcoin’s block reward halving in May 2020 crossed a profitability threshold, triggering a shift in mining pool dominance from China to Central Asia.",
      "domain": "economics"
    }
  ],
  "relations": [],
  "used_by": [],
  "forms": [
    "cusp",
    "cusps"
  ],
  "closed": false,
  "provenance": {
    "author": "retrofit:qwen/qwen3-235b-a22b-2507",
    "date": "2026-07-29",
    "confidence": 0.8,
    "sources": [
      "Sample/we-already-had-the-words.md"
    ],
    "reconciled": {
      "by": "openrouter:qwen/qwen3-235b-a22b-2507",
      "date": "2026-07-31",
      "changed": "factual",
      "note": "Definition was factually misaligned with components. Missing foundational concepts identified in definition were added. Definition kept as is because it correctly describes emergent behavior after com"
    }
  },
  "canonical": "https://emergencemachine.com/tools/lexicon/what-is-the-meaning-of-cusp.threshold"
}