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

Change in orbit due to moment of inertia change?

  1. Jan 16, 2014 #1

    So recently I read about the massive 3 gorges dam changing the mass moment of inertia of the Earth to such an extent that the days will now be 60ns longer.

    Then I thought, how will this effect the orbit of the Earth about the Sun?

    Any thoughts?
  2. jcsd
  3. Jan 16, 2014 #2


    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper

    Wow! A whole 60 ns longer each day! Man, I can catch some additional zzzs every morning!

    I wouldn't worry about any orbital changes w.r.t. the earth's movement about the sun.

    BTW, in 60 ns, a beam of light travels about 18 meters.

    It would also take over 160 million years to add an additional HOUR to each day.
  4. Jan 16, 2014 #3

    D H

    User Avatar
    Staff Emeritus
    Science Advisor

    It won't. It hasn't changed the Earth's mass one iota, nor has it changed the distance between the Earth's center of mass and the Sun.
  5. Jan 16, 2014 #4


    User Avatar
    Homework Helper

    what about tidal locking effects between the earth and the sun? I guess it is negligibly small, since the size of the earth and sun is very small compared to the distance between them.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Discussions: Change in orbit due to moment of inertia change?