{
  "export": {
    "source": "https://urth.darkrealm.vip/thread/whorl/453",
    "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": 453,
    "subject": "Asteroid & L-5 Numbers",
    "messages": 2,
    "voices": 1,
    "first": "1997-10-08T01:19:00+00:00",
    "last": "1997-10-08T05:38:00+00:00"
  },
  "messages": [
    {
      "message_id": "<whorl-v0007-0604@digest.urth.net>",
      "from": {
        "name": "m.driussi",
        "address": "m.driussi at genie.com"
      },
      "date": "1997-10-08T01:19:00+00:00",
      "subject": "(whorl) Asteroid & L-5 Numbers",
      "in_reply_to": null,
      "reply_link": null,
      "blocks": [
        {
          "kind": "text",
          "depth": 0,
          "text": "Reply:  Item #7581861 from WHORL at LISTS.BEST.COM@INET02#\n\nNope, the idea that the whorl was carved from an asteroid (rather\nthan being built up from beams and ship plate) did not arise outside\nof the text in the minds of overeager readers--rather, it was told\nspecifically by an old chem soldier to someone else in the text.  This\nwas also the point where the weather-related rational for the tunnels\nwas divulged, I believe.  Somebody else can find it, no doubt.\n\nRe: 9.80616 m/sec^2 as being equal to \"78,986 miles per hour per\nhour,\" hmmmm.  This looks odd, because Earth's escape velocity is \"7\nmiles/sec, or 25,000 mph\" (Adams, SPACEFLIGHT, 1958, p. 177).\n\nI believe the question with a simulated g (as in a spinning cylinder)\nis not so much overcoming the simulated g-force as it is in\novercoming the rotational speed.  [ . . . well . . . see later.]\n\nTHE SCIENCE IN SCIENCE FICTION (p. 19) offers a few L-5 space colony\nmodels that might be of interest here:\n\n          Length    Dia.     RPM    Population max\nModel 1    0.62     0.12     2.85       10,000\nModel 2    2.0      0.4      1.67      200,000\nModel 3    6.2      1.2      0.95    2,000,000\nModel 4   20        4        0.53   20,000,000\n\n(simplified chart, using only miles.  RPM = Revolutions per minute to\ncreate a simulated 1 g at the surface.)\n\nNow let's look at the biggest one, No. 4.  Dia = 4 miles, thus\ncircumference = 12.56 miles; RPM of 0.53 therefore translates into\n6.66 miles/minute or 400 miles per hour.\n\nIn contrast, No. 3's Dia = 1.2 means Circ = 3.76 miles; RPM 0.95 =>\n214 miles per hour.\n\nWell hey, that's pretty much what John Eric Ivancich came up with!\nSo nevermind my initial doubts, we agree on this much!  (BTW, Welcome\naboard John Eric Ivancich.)\n\nIn addition to all this, which still looks like a formidable speed to\novercome, there is the fact that a human being, a child even, can\nactually jump up from the Earth.  Compared to a child jumping on the\nwhorl, the floater has two vectors: one horizontal (the \"go\" vector) and\none vertical (the \"float\" vector); as the simulated g force is reduced (by\ntravelling in the direction of rotation with the go vector) the float\nvector faces less resistance.  The floater suddenly has the uplifting\ncapacity of a micro-helicopter (but not the aerodynamic shape, nor control\nsurfaces for true air flight).\n\nSo then, assuming my calculations above are close enough, we'll say\nthat 400 mph will cancel out 1 g(sim) in model colony 4.\n\nNow, doesn't that imply that if we can reach 200 mph we will have only .5\ng(sim) \"holding us down\"?  And at 100 mph we'd have only .75 g(sim)?\n\nA blower that can hover a vehicle, and provide brief pop-ups of six\nto eight feet to clear obstacles (as Grissom showed Silk that Blood's\ncivilian floater could do), such a blower could probably really loft\na vehicle that only weighs three-fourths as much, I'm thinking.\n\nBut yeah, yeah, Ringworld's a-going down, boys--everybody into the\nlifeboats and let's pray that the rubber band powered warp drives\ncan holdout until we can get back to the green hills of Earth! :)\n\n=mantis="
        }
      ]
    },
    {
      "message_id": "<whorl-v0007-0605@digest.urth.net>",
      "from": {
        "name": "m.driussi",
        "address": "m.driussi at genie.com"
      },
      "date": "1997-10-08T05:38:00+00:00",
      "subject": "(whorl) Asteroid & L-5 Numbers",
      "in_reply_to": "<whorl-v0007-0604@digest.urth.net>",
      "reply_link": "subject",
      "blocks": [
        {
          "kind": "text",
          "depth": 0,
          "text": "Reply:  Item #9713026 from WHORL at LISTS.BEST.COM@INET03#\n\nUh, make that \"moving =against= the direction of rotation rather than\nwith it.\"  That is, if I understand it correctly, the rotation is from\nsouth to north, so that when one drives to the south one is subtracting\nfrom the very velocity vector that provides the simulated gravity.\n\n=mantis="
        }
      ]
    }
  ]
}