"no-hair theorem" meaning in English

{
  "etymology_text": "Hair is a metaphor for the unnecessary information beyond the three proposed parameters.",
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      "expansion": "no-hair theorem (uncountable)",
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  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
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        {
          "kind": "topical",
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          "name": "Black holes",
          "orig": "en:Black holes",
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      "glosses": [
        "A theorem postulating that all black hole solutions of the Einstein-Maxwell equations in general relativity can be completely characterized by only three externally observable classical parameters: mass, electric charge, and angular momentum."
      ],
      "id": "en-no-hair_theorem-en-noun-aZot9F32",
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          "black hole",
          "black hole"
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          "general relativity",
          "general relativity"
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          "observable",
          "observable"
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        [
          "mass",
          "mass"
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        [
          "electric charge",
          "electric charge"
        ],
        [
          "angular momentum",
          "angular momentum"
        ]
      ],
      "tags": [
        "uncountable"
      ],
      "wikipedia": [
        "no-hair theorem"
      ]
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  "word": "no-hair theorem"
}

{
  "etymology_text": "Hair is a metaphor for the unnecessary information beyond the three proposed parameters.",
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  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
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        "en:Black holes"
      ],
      "glosses": [
        "A theorem postulating that all black hole solutions of the Einstein-Maxwell equations in general relativity can be completely characterized by only three externally observable classical parameters: mass, electric charge, and angular momentum."
      ],
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          "theorem"
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          "black hole"
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          "general relativity",
          "general relativity"
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          "observable",
          "observable"
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        [
          "mass",
          "mass"
        ],
        [
          "electric charge",
          "electric charge"
        ],
        [
          "angular momentum",
          "angular momentum"
        ]
      ],
      "tags": [
        "uncountable"
      ],
      "wikipedia": [
        "no-hair theorem"
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  "word": "no-hair theorem"
}