PUZZLE #4827: Spacetime Causality Cipher (diff 3)

spacetime-causality learn difficulty: 3/7 simulate author: system unsolved

Light consists of massless particles called photons. Their speed is constant in all reference frames — the cornerstone of special relativity.

DATA

Events	`{'label': 'C', 'x': 3, 't': 2}, {'label': 'Z', 'x': 7, 't': 3}, {'label': 'o', 'x': -2, 't': 6}, {'label': 'I', 'x': -5, 't': 1}, {'label': 'n', 'x': -3, 't': 15}, {'label': 'o', 'x': -2, 't': 11}, {'label': 't', 'x': -2, 't': 9}, {'label': 'p', 'x': 0, 't': 0}, {'label': 'V', 'x': 4, 't': 3}, {'label': 'h', 'x': 0, 't': 2}, {'label': 'J', 'x': 5, 't': 2}`
Speed Of Light	`1`
Hint	`Spacetime diagram: 6 of 11 events are in the future light cone of (0,0). An event (x, t) is causally connected if \|x\| ≤ c·t where c=1. Filter out spacelike events (\|x\| > t), sort remaining by t. GPS satellites use this same physics to maintain cm-level accuracy.`
Answer Format	`lowercase word (the causally connected message)`

{
  "type": "spacetime-causality",
  "events": [
    {
      "label": "C",
      "x": 3,
      "t": 2
    },
    {
      "label": "Z",
      "x": 7,
      "t": 3
    },
    {
      "label": "o",
      "x": -2,
      "t": 6
    },
    {
      "label": "I",
      "x": -5,
      "t": 1
    },
    {
      "label": "n",
      "x": -3,
      "t": 15
    },
    {
      "label": "o",
      "x": -2,
      "t": 11
    },
    {
      "label": "t",
      "x": -2,
      "t": 9
    },
    {
      "label": "p",
      "x": 0,
      "t": 0
    },
    {
      "label": "V",
      "x": 4,
      "t": 3
    },
    {
      "label": "h",
      "x": 0,
      "t": 2
    },
    {
      "label": "J",
      "x": 5,
      "t": 2
    }
  ],
  "speed_of_light": 1,
  "note": "6 causally connected events + 5 spacelike events (noise). Sort by time after filtering.",
  "hint": "Spacetime diagram: 6 of 11 events are in the future light cone of (0,0). An event (x, t) is causally connected if |x| \u2264 c\u00b7t where c=1. Filter out spacelike events (|x| > t), sort remaining by t. GPS satellites use this same physics to maintain cm-level accuracy.",
  "answer_format": "lowercase word (the causally connected message)"
}

author's note: Pool fill: spacetime-causality diff 3