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Homework Help: Topology of curved space

  1. Apr 30, 2008 #1
    [SOLVED] Topology of curved space

    1. The problem statement, all variables and given/known data
    The distance between a point (r, theta) and a nearby point (r + dr, theta + d\theta) on a positively curved sphere is given by

    ds^2 = dr^2 + R^2 \sin ^2 (r/R)d\theta ^2

    NOTE: I mean that ds^2 = (ds^2). My question is - how do I use this formula? What is what - can you explain it to me?
  2. jcsd
  3. Apr 30, 2008 #2


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    I'm not sure what your question is. You titled this "Topology of curved space" but topology does not concern itself with distances. You give a formula that involves R but don't say what R is. Apparently your "positively curved sphere" is a sphere of radius R. And if that is the case, then what are your coordinates? In particular, what is "r"?
  4. Apr 30, 2008 #3
    We are dealing with cylindrical coordinates.

    So ds is the distance between points (r, theta) and (r+dr, theta + d theta).

    Yes, R is the radius of the sphere - I'm sorry I did not mention that earlier.
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