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

Clocks on earth

  1. Jul 24, 2006 #1
    Clocks show less elapsed time in gravitational field right?
    So clocks on Earth seem to apply.

    Consider one clock stationed on the north pole and one somewhere on the equator, both at sea level.

    It seems there are a couple of factors in order to calculate the difference in time between each clock and a fictional observer in flat space.

    Looks like we have to take into consideration the following things

    They are in a gravitational field
    The EM-force accelerates in the opposite direction
    The Earth is rotating,
    Both clocks are accelerating due to the rotation (each one slightly different).
    The earth is not a perfect sphere.

    My main question concerning this problem is the "cancellation" of the EM-force. How does the EM force interact with the curvature? Are there well established theories for this?
    Last edited: Jul 24, 2006
  2. jcsd
  3. Jul 24, 2006 #2


    User Avatar
    Staff Emeritus
    Science Advisor

    It's somewhat well known that all clocks on the geoid (intuitively, at sea leve) tick at the same rate.

    I'm not sure what your concerns with the "EM field" are. You don't need to know the acceleration of a clock to know how it keeps time - you only need to know the metric, and the velocity of the clock.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook