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Is gravity a force?

  1. Sep 8, 2013 #1
    Gravity, as defined by Einstienien Theory, is a warping of space. And any mass traveling through space will take the path of least inertial resistance, ie not necessarily a straight line, dependent on that warping of space. So, is gravity a force, or just an expression of warped space, that happens to influence matter passing through it?
  2. jcsd
  3. Sep 8, 2013 #2


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    Staff: Mentor

    See this thread: https://www.physicsforums.com/showthread.php?t=207078

    I'll quote the last post.

  4. Sep 8, 2013 #3


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    Science Advisor

    Space-time not just space.

    A free falling object travels on straight paths (geodesics) in wrapped space-time, which might look curved when projected onto space.

    Both models can be used to describe the common effect of mass attraction. But Einstein's model predicts some effects like light bending better than Newton's model, and gravitational time dilation which Newton doesn't predict at all.

    Also note that even in Einsteins model you can treat gravity as a force, but unlike in Newton's model it is an inertial force due to an accelerated reference frame, not an interaction force:

    But if you model the accelerated reference frame with distorted coordinates, instead of inertial forces, then indeed there is no "force of gravity". And free falling a objects follow a straight path as shown in this animation:

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