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Posers and Puzzles

Posers and Puzzles

  1. Subscriber sonhouse
    Fast and Curious
    09 May '07 15:53
    Back to our toroid planet, remember our discussion about whether you could get into orbit on a perfect roadway on the moon (no atmosphere, plenty of energy available).
    OK, so now we make the same kind of roadway around our newly constructed donut planet, around the skinny part of the donut, not sure the terminology, Not the wide way round but going through the hole, ok? Same conditions. vacuum, perfect roadway, plenty of energy, whether fusion, solar, whatever. Do the conditions around our donut planet change things for our quest to be able to drive into orbit?
  2. Standard member PBE6
    Bananarama
    09 May '07 17:17
    Originally posted by sonhouse
    Back to our toroid planet, remember our discussion about whether you could get into orbit on a perfect roadway on the moon (no atmosphere, plenty of energy available).
    OK, so now we make the same kind of roadway around our newly constructed donut planet, around the skinny part of the donut, not sure the terminology, Not the wide way round but going through ...[text shortened]... e conditions around our donut planet change things for our quest to be able to drive into orbit?
    Won't the car fall in towards the centre of the toroid? The gravity force lines should all point inward like spokes on a bicycle wheel.
  3. Standard member leisurelysloth
    Man of Steel
    09 May '07 17:37
    Originally posted by PBE6
    Won't the car fall in towards the centre of the toroid? The gravity force lines should all point inward like spokes on a bicycle wheel.
    I would think it would be the other way around--inside the toroid the gravity force lines would all point out like the spokes on a bicycle wheel and the very center would be an unstable "tipping" point (if you were perfectly centered you could balance there, but the slightest nudge would cause you to fall out of the center towards the toroid). If this is correct, then I would think that you could simply drive/accelerate in circles inside the toroid until you reach escape velocity, and then a quick turn and you're outta there!
  4. Standard member PBE6
    Bananarama
    09 May '07 17:58
    Originally posted by leisurelysloth
    I would think it would be the other way around--inside the toroid the gravity force lines would all point out like the spokes on a bicycle wheel and the very center would be an unstable "tipping" point (if you were perfectly centered you could balance there, but the slightest nudge would cause you to fall out of the center towards the toroid). If thi ...[text shortened]... ide the toroid until you reach escape velocity, and then a quick turn and you're outta there!
    Oh yeah, I forgot. I think you're right about that. Hey, can someone MatLab this sucker and find an expression for the gravitational field around a torus with a uniform density?
  5. Subscriber AThousandYoung
    Proud Boys Beware
    09 May '07 21:15
    Originally posted by PBE6
    Oh yeah, I forgot. I think you're right about that. Hey, can someone MatLab this sucker and find an expression for the gravitational field around a torus with a uniform density?
    http://www.mathpages.com/home/kmath402/kmath402.htm
  6. Subscriber sonhouse
    Fast and Curious
    11 May '07 15:57
    Looks bloody complicated, what happened to good old 1/R^2
    But it's clear on the outside of the circular path there is more gravity than on the inside path so if you can accel to full speed in a half circuit then maybe when you reach the inner side the gravity will be enough less to allow the craft to start an orbit.