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Sep 13, 2017 at 16:27 comment added Narasimham These trajectories depend strongly on initial conditions.
Sep 13, 2017 at 16:11 comment added Joseph O'Rourke @Narasimham: 2:1:1. See the explicit equation of the ellipsoid in my post.
Sep 13, 2017 at 16:09 comment added Narasimham What were axes proportions you have used? I am almost sure analytical $ r- \theta $ relation involves elliptic integrals whose periodicity determines closed geodesics formation.
Jul 24, 2017 at 17:36 history edited Joseph O'Rourke CC BY-SA 3.0
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Jul 24, 2017 at 13:10 answer added Robert Bryant timeline score: 10
Jul 24, 2017 at 11:55 history edited Joseph O'Rourke CC BY-SA 3.0
Image links broken; now fixed.
Apr 13, 2017 at 12:58 history edited CommunityBot
replaced http://mathoverflow.net/ with https://mathoverflow.net/
Jul 24, 2012 at 0:37 history edited Joseph O'Rourke CC BY-SA 3.0
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Jul 23, 2012 at 11:57 comment added Joseph O'Rourke @Ben: You were right to be suspicious! My method of computing the angular turn at each point of the curve was incorrect. I agree that closure should not be so prevalent.
Jul 23, 2012 at 9:58 history edited Joseph O'Rourke CC BY-SA 3.0
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Jul 23, 2012 at 5:07 comment added user21349 It's strongly counterintuitive to me that randomly chosen initial conditions would lead with nonzero probability to a simple closed curve. For the curves you showed, did you choose initial conditions that had special symmetry? Did you verify with high precision, or only visually, that they returned to the same point with the same tangent vector?
Jul 22, 2012 at 20:42 history edited Joseph O'Rourke CC BY-SA 3.0
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Jul 22, 2012 at 20:19 comment added user21349 In the degenerate case of a cylinder, you can clearly get non-simple closed curves curves. Draw a circle on a piece of paper and roll the paper up into a tube so that it self-intersects. For a prolate ellipsoid whose long axis is long compared to the scale set by the curve's curvature, you should get the same behavior.
Jul 22, 2012 at 18:35 history edited Joseph O'Rourke CC BY-SA 3.0
(Not sure they are "inexact," but they are "naive.")
Jul 22, 2012 at 18:02 history edited Joseph O'Rourke CC BY-SA 3.0
Added ellipsoid experiments.
Jul 21, 2012 at 0:13 history edited Joseph O'Rourke CC BY-SA 3.0
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Jul 20, 2012 at 17:59 comment added Joseph O'Rourke @Will: A geometric picture!
Jul 20, 2012 at 14:58 comment added Will Sawin do you want a geometric picture or a mathematical formula?
Jul 20, 2012 at 12:06 history asked Joseph O'Rourke CC BY-SA 3.0