{
  "export": {
    "source": "https://urth.darkrealm.vip/thread/urth/3640",
    "note": "Exported from an unofficial mirror of a public mailing list. Copyright in each message remains with the person who wrote it.  Email addresses are obscured as `user at host`, the form the original archive published. This file was rebuilt from parsed fields rather than retained headers, so it is faithful in content but not byte-exact.",
    "addresses": "obscured as 'user at host'"
  },
  "archive": "urth",
  "thread": {
    "id": 3640,
    "subject": "time dilation terminology",
    "messages": 2,
    "voices": 2,
    "first": "2002-12-03T00:30:33+00:00",
    "last": "2002-12-03T00:39:40+00:00"
  },
  "messages": [
    {
      "message_id": "<urth-v0212-2334@digest.urth.net>",
      "from": {
        "name": "Michael Andre-Driussi",
        "address": "mantis at siriusfiction.com"
      },
      "date": "2002-12-03T00:30:33+00:00",
      "subject": "(urth) time dilation terminology",
      "in_reply_to": null,
      "reply_link": null,
      "blocks": [
        {
          "kind": "quote",
          "depth": 1,
          "text": "Blattid wrote:\nUm, no, Mantis ... in a world that obeys Einstein's rules,\n\"time\" is equally [ob|sub]jective in any inertial reference\nframe; more specifically, \"time\" on the Whorl cruising at\nNAFAL velocities is no more and no less objective than \"time\"\non the surface of Urth. This is a consequence of \"time\" not\nbeing an independent entity in such a world; it is one\ndimension of a four-or-more-dimensional manifold which we\n(more) properly refer to as \"spacetime.\"\n\nThe \"objective time\"/\"subjective time\" terminology you use\ncomes, not from relativistic physics, but from SF writers\nwho play with these concepts in their novels but either\ndo not comprehend what I oversimplify in the previous\nparagraph, or else assume (and I think this quite likely)\nthat most \"users\" of NAFAL ships would think this way, the\nnon-absolute nature of spacetime in an Einsteinian universe\nbeing kind of difficult to wrap one's head around. (I do\nnot claim to have my head all the way around it by any\nmeans!)"
        },
        {
          "kind": "text",
          "depth": 0,
          "text": "Unless you are trying to tell me that there is no time dilation at\nrelativistic speeds, which would be an interesting claim, then this looks\nto be another flea circumcising exercise on the terms Objective and\nSubjective.  Worthy of litcrit, and literary theory, and philosophy (where\nthese terms are Big Terms indeed).\n\nAs I was using it,\n\n\"Objective time\"  = t(o) = \"interval of time experienced by an observer in\nthe coordinate system (at rest)\"\n\n\"Subjective time\" = t = \"time recorded by a clock moving in the rocket at a\nconstant velocity V across space\"\n\nc = \"velocity of light in a vacuum\"\n\nt = t(o)/Square root(1-(V^2/c^2))\n\nWould you prefer I use \"t\" and \"t(o)\" instead of Subjective and Objective?\nI mean, criminy, you make it sound like I'm selling the Dean Drive here!\nGimme a break!\n\n=mantis="
        }
      ]
    },
    {
      "message_id": "<urth-v0212-2336@digest.urth.net>",
      "from": {
        "name": "Dan'l Danehy-Oakes",
        "address": "ddanehy at siebel.com"
      },
      "date": "2002-12-03T00:39:40+00:00",
      "subject": "RE: (urth) time dilation terminology",
      "in_reply_to": "<urth-v0212-2334@digest.urth.net>",
      "reply_link": "subject",
      "blocks": [
        {
          "kind": "quote",
          "depth": 1,
          "text": "Mantis wrote:\nUnless you are trying to tell me that there is no time \ndilation at relativistic speeds, which would be an \ninteresting claim, "
        },
        {
          "kind": "text",
          "depth": 0,
          "text": "It would, but I'm not. The question then becomes whose\nspeed is relative ... when you say that"
        },
        {
          "kind": "quote",
          "depth": 1,
          "text": "\"Objective time\"  = t(o) = \"interval of time experienced by \nan observer in the coordinate system (at rest)\""
        },
        {
          "kind": "text",
          "depth": 0,
          "text": "which coordinate system are you saying is \"at rest?\" At\nrest relative to what? Are you invoking luminiferous aether?\nWithout that, the coordinate system of the _Whorl_ -- except\nduring the boost phases -- is as legitimately \"at rest\" as\nthat of Urth; or, taking your other (verbal) reference frame,"
        },
        {
          "kind": "quote",
          "depth": 1,
          "text": "\"Subjective time\" = t = \"time recorded by a clock moving in \nthe rocket at a constant velocity V across space\""
        },
        {
          "kind": "text",
          "depth": 0,
          "text": "there's no \"space\" for it to be moving \"at a constant\nvelocity across\" -- once boost stops, it's moving along\nits natural worldline away, which happens to be at a more\nor less constant velocity relative to the Urth system ...\nbut it's quite as legitimate (though generally less \nconvenient) to declare that Urth is moving away from the \n_Whorl_."
        }
      ]
    }
  ]
}