Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Gravitational Time and Length Change, Looking for mass formula

  1. Nov 12, 2014 #1
    Hi, Just curious if anyone knows of a formula that would show how mass changes in a gravitational field? I have seen the formulas for gravitational time dilation and length contraction (which are rather similar) and was wondering is mass changes the same way.

    Thanks
     
  2. jcsd
  3. Nov 12, 2014 #2

    phinds

    User Avatar
    Gold Member
    2016 Award

    Mass does not change in a gravitational field.
     
  4. Nov 12, 2014 #3

    PeterDonis

    User Avatar
    2016 Award

    Staff: Mentor

    What formulas have you seen for "gravitational length contraction"?
     
  5. Nov 12, 2014 #4
    Just to pick an extreme, a 1kg ball is a meter away from the event horizon of a black hole. So, to an outside observer, time is almost not moving at all for the 1 kg ball and its size has shrunk to almost a point due to gravitational length and time dilation but the ball would still be 1 kg?
     
  6. Nov 12, 2014 #5
    hmm i just figured since planck time and planck length are related by a factor of c that they would change the same.
     
  7. Nov 12, 2014 #6

    PeterDonis

    User Avatar
    2016 Award

    Staff: Mentor

    What are you basing this on? What formula? Do you have a reference?

    The Planck time and Planck length are not the same as the length of an object or its proper time.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Gravitational Time and Length Change, Looking for mass formula
  1. Time, mass and length (Replies: 38)

Loading...