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I've seen it printed multiple places, here for example, that the reason orbits are elliptical is because the gravitational law has an inverse square of the radius. Why does this make the orbits elliptical?


marked as duplicate by Floris, Qmechanic Jun 14 '16 at 2:54

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    $\begingroup$ Have you heard about Betrand's theorem? en.wikipedia.org/wiki/Bertrand%27s_theorem $\endgroup$ – CuriousOne Jun 14 '16 at 2:42
  • $\begingroup$ Comes out of the equations for a 1/r potential (which gives you 1/r^2 force). Don't read many printed stories on it, just get a classical mechanics book for junior/seniors and they are easily derived. It worthwhile reading and maybe even semis tidying some authoritative normal textbooks rather than looking for things printed here and there that seems like magic to you. Not a lot of magic around, you can actually try to get some education. I don't say that to be mean, just that there is a lot of knowledge around, decide what interests you and read on it from the basics up. $\endgroup$ – Bob Bee Jun 14 '16 at 2:51