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Pressure and curvature

  1. May 5, 2015 #1
    [Moderator note: This has been spun off into a separate thread from here.]

    I've never been on a forum so I apologize if I'm asking a question in the wrong place. If so, would someone kindly directing me where to post.
    If gravity warps space around mass, wouldn't the curving of space create pressure of force with momentum on the object warping it? Bad example but kinda like filling up a clear plastic bag and pressins a ball up against it.
    Last edited by a moderator: May 5, 2015
  2. jcsd
  3. May 5, 2015 #2
    Correct the method is described via the stress energy tensor. ( included earlier this post)

    Here is three detailed articles on the subject
    http://arxiv.org/abs/astro-ph/0409426 An overview of Cosmology Julien Lesgourgues
    http://arxiv.org/pdf/hep-th/0503203.pdf "Particle Physics and Inflationary Cosmology" by Andrei Linde
    http://www.wiese.itp.unibe.ch/lectures/universe.pdf:" Particle Physics of the Early universe" by Uwe-Jens Wiese Thermodynamics, Big bang Nucleosynthesis
    Last edited: May 5, 2015
  4. May 5, 2015 #3
    Much appreciated, and since I have your attention, one more question... Does time slow near mass due to the curve in space creates a longer distance to travel than it would in a straight line?
  5. May 5, 2015 #4
    You will need to specify the observer. To the outside observer time slows down due to higher mass, however to the perspective of the infalling test particle time is the same

    The relations are well explained here
    Last edited: May 5, 2015
  6. May 5, 2015 #5


    Staff: Mentor

    As Mordred said, whether time "slows" depends on who the "time" is being measured relative to. However, even in the case where time does "slow"--when the outside observer is at rest relative to the massive object--this slowing is not due to space curvature. Space curvature means that, for example, if you measure the angles of a triangle that encloses the mass, the angles will not sum to 180 degrees. This is a different effect from the slowing of time.
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