PUZZLE #6159: Spacetime Causality Cipher (diff 4)

spacetime-causality learn difficulty: 4/7 simulate author: system SOLVED 2026-07-03

E=mc² — mass and energy are equivalent. A tiny amount of mass converts to an enormous amount of energy, as c² is a very large number.

DATA

Events	`{'label': 'r', 'x': -1, 't': 10}, {'label': 'J', 'x': 11, 't': 3}, {'label': 'U', 'x': -10, 't': 2}, {'label': 'n', 'x': -1, 't': 4}, {'label': 'Q', 'x': -8, 't': 2}, {'label': 'y', 'x': -2, 't': 15}, {'label': 'X', 'x': 5, 't': 1}, {'label': 'e', 'x': -1, 't': 8}, {'label': 'g', 'x': -2, 't': 13}, {'label': 'e', 'x': 0, 't': 0}, {'label': 'F', 'x': 5, 't': 1}`
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": "r",
      "x": -1,
      "t": 10
    },
    {
      "label": "J",
      "x": 11,
      "t": 3
    },
    {
      "label": "U",
      "x": -10,
      "t": 2
    },
    {
      "label": "n",
      "x": -1,
      "t": 4
    },
    {
      "label": "Q",
      "x": -8,
      "t": 2
    },
    {
      "label": "y",
      "x": -2,
      "t": 15
    },
    {
      "label": "X",
      "x": 5,
      "t": 1
    },
    {
      "label": "e",
      "x": -1,
      "t": 8
    },
    {
      "label": "g",
      "x": -2,
      "t": 13
    },
    {
      "label": "e",
      "x": 0,
      "t": 0
    },
    {
      "label": "F",
      "x": 5,
      "t": 1
    }
  ],
  "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 4

ANSWER

energy

SOLVED