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Homework Help: Is our moon epicyclic?

  1. Jan 7, 2013 #1
    Hi, A quick clarification question. Is epicyclic a correct description for our moons path around the sun. I can only find references to epicycles in a historical context.

  2. jcsd
  3. Jan 7, 2013 #2


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    Hi Minki! :smile:
    Epicycles are an approximation … the number of cycles gives you the order of the approximation.

    The only actual epicylces I know of are what are usually called planetary gears, see http://en.wikipedia.org/wiki/Epicyclic_gearing :wink:
  4. Jan 7, 2013 #3

    Simon Bridge

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    Focus on what it means for an orbit to be epicyclic and you can answer the question yourself.

    example of a modern use.

    But perhaps you are thinking that, maybe, the Moon's orbit (in, say, the reference frame of the Earth-Moon center-of-mass) traces out some sort of complicated scribble rather than a simple ellipse?
  5. Jan 16, 2013 #4
    Ok, thanks for that guys.
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