{
  "export": {
    "source": "https://urth.darkrealm.vip/thread/urth/1458",
    "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": 1458,
    "subject": "Paradoxes [Digest urth.v024.n023]",
    "messages": 1,
    "voices": 1,
    "first": "1999-03-30T14:36:50+00:00",
    "last": "1999-03-30T14:36:50+00:00"
  },
  "messages": [
    {
      "message_id": "<urth-v0024-0105@digest.urth.net>",
      "from": {
        "name": "John Bishop",
        "address": "jbishop at blkbrd.zko.dec.com"
      },
      "date": "1999-03-30T14:36:50+00:00",
      "subject": "(urth) Re: Paradoxes [Digest urth.v024.n023]",
      "in_reply_to": null,
      "reply_link": null,
      "blocks": [
        {
          "kind": "text",
          "depth": 0,
          "text": "It's not true that all time-travel (properly considered) \nhas to lead to paradoxes.\n\nFirst, forward-in-time travel is non-paradoxical.  The\nproof is that we are doing it right now!  Vinge did a lot\nwith fowards-only time travel, as have others (the oldest\nsuch story I know of is _Sleeping_Beauty_, but _Rip_van_Winkel_\nis more aware of the difference between the \"now\" of the\nsleeper and the present).\n\nSecond, in the many-worlds model, timelines split at \"change\npoints\", either for all change points [to support quantuum\nmechanics] or just for \"imposed\" points due to time travellers;\nin that case, backwards time travel is non-paradoxical:\n\n   The mad scientist Dr. Parah travels from 1999 to \n   2002 and grabs copies of the best-selling novels\n   from a bookstore.  He than travels back to 1999 \n   and (having copied them) sends the manuscripts\n   to publishers as his own work.  \n\nThe original author still wrote the book during 2000 in \ntimeline 1, and though the book appears full-fledged (with\nno apparent author) in 1999 in timeline 2, that's not a\nparadox.  Note that the theft from the bookstore only \nhappens in timeline 1.\n\n\"Many worlds\" is prodigal of universes, but logically consistent.\nThe movie \"Sliding Doors\" is an example.\n\nThird is the one I think more Wolfean: rather than a huge number\nof timelines, we have a universe in which history has near-repeats.\nSimiliar causes, similiar effects: so there are ages of barbarism\nand of civilization, ages of discovery and of forgetting.\n\nThen you have a Severian, in one cycle, write a book but not read\nit.  Another Severian (very much like the first) reads the book and\nmay or may not write another, etc.\n\nSee the discussion in Steven Pinker's _How_the_Mind_Works_ of how\nrepetition in time (via generations) can mimic backwards or\ncircular causation.\n\n\t-John Bishop"
        }
      ]
    }
  ]
}