{
  "export": {
    "source": "https://urth.darkrealm.vip/thread/whorl/452",
    "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": "whorl",
  "thread": {
    "id": 452,
    "subject": "More about Physics",
    "messages": 1,
    "voices": 1,
    "first": "1997-10-08T02:33:00+00:00",
    "last": "1997-10-08T02:33:00+00:00"
  },
  "messages": [
    {
      "message_id": "<whorl-v0007-0603@digest.urth.net>",
      "from": {
        "name": "m.driussi",
        "address": "m.driussi at genie.com"
      },
      "date": "1997-10-08T02:33:00+00:00",
      "subject": "(whorl) More about Physics",
      "in_reply_to": null,
      "reply_link": null,
      "blocks": [
        {
          "kind": "text",
          "depth": 0,
          "text": "A few more thoughts--\n\n\"Zero Gravity\" is experienced by the jumping child at apogee; by the\ncannonball at apogee; by the passengers of the infamous \"vomit comet\"\nastronaut trainer B-52 when it goes into a steep dive.  Or people in\na free-falling elevator.\n\nSo since Silk's floater flight is basically as ballistic as a\ncannonball ride, we can try to time the arc, estimate the altitude at\napogee, gauge the time of \"true\" zero gravity, etc., all as another\napproach to analyzing the whole thing and therefore the physical\nnature of the whorl.\n\n(The vomit comet goes for ten minute bursts--or was it shorter?  More\nlike three minutes?  They talked about it regarding the filming of\nmotion picture \"Apollo 13\" which used the vomit comet.)\n\n(And while Silk sees things \"falling up\" in the floater cabin,\nsuggesting true zero gravity, doesn't it turn out to be the fact that\nthe floater has rolled over and is upside down?  So that when Silk pokes\nhis head out for a peek he nearly plummets?)\n\nFWIW, since THE SCIENCE IN SCIENCE FICTION gives 16 km as the max\ndiameter for a generation starship (as I'm sure I mentioned before),\nI ran the formula with that diameter of 10 miles and get a\ngroundspeed of 628 mph.\n\n=mantis="
        }
      ]
    }
  ]
}