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World whirled

  1. Dec 4, 2008 #1
    What place on Earth moves the fastest?
     
  2. jcsd
  3. Dec 5, 2008 #2

    Evo

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    Staff: Mentor

    As in plate tectonics?
     
  4. Dec 5, 2008 #3
    I take this to mean (based on the thread title) which place moves fastest in relation to the Earth's rotation. Taking into account proximity to the equator and altitude, I would vote for the top of Mount Kilimanjaro.
     
  5. Dec 5, 2008 #4

    DaveC426913

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    ... at midnight, in winter (perigee), just for good measure.:wink:
     
  6. Dec 5, 2008 #5

    Evo

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    I thought of that, but I think plate tectonics are more interesting. North America & Europe move about an inch apart every year. A location that was at a specific latitude and longitude years ago, would no longer be at that point. I know this is an issue that has had to be taken into account for GPS.
     
  7. Dec 5, 2008 #6
    There are mountains near the equator in South America which might take the cake. Although I had meant whirling as a result of Earth's rotation, I believe I once saw an interesting map representing tectonic movements (slowest wins?) :smile:
     
  8. Dec 5, 2008 #7
    Not really, think again.

    Meanwhile, the winner is Chimborazo

     
  9. Dec 5, 2008 #8

    DaveC426913

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    No?

    At midnight(ish), the Earth's rotation and its revolution about the sun will be cumulative.
    In (North American) winter, Earth is at its perigee, thus moving fastest in its orbit. (OK, Kilimanjaro is actually in the S.Hemisphere, so it would be summer there...)

    I was facetiously considering this point on Earth with respect to a point outside both the Earth and, in fact, the Solar system.
     
  10. Dec 5, 2008 #9
    You are right, good thinking.
     
  11. Dec 19, 2008 #10

    Ian

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    Loren,
    If a sphere like has an axis of rotation through its north and south poles, as you observe it rotating you would see that its equatorial plane has the fastest motion on the spheres surface.
    If we add another axis of rotation perpendicular to the poles (i.e., through its equator) and rotate the sphere through this second axis at the same velocity of rotation as the polar axis, you will observe the sphere to rotate as though it were inclined at 45 degrees.
    The real velocity of maximum rotation on the spheres surface would then be twice the observed value because of the existence of the illusion that makes us think the sphere is actually leaning over at 45 degrees.
    If we change the velocity of rotation of the eqatorial axis - lets say we reduce it so it is half the velocity of rotation of the polar axis the 45 degree angle of inclination will become 22.5 degrees, but we will still think it is leaning over and not bolt upright, because of the illusion.
    There is no way to tell if the earth is rotating on one or two axes (because of the illusion)and therefore we simply cannot tell which part of our planet is fastest moving in reality.

    Look at the way the planets appear to rise and fall almost in a zig-zag across the sky as we observe them from the earth. Their motion is only seen that way because of our vantage point on earth, from outside the solar system our view would be rather different.
    Consequently, you have asked an impossible question because we cannot tell if the earth is rotating on one, two or even three axes. If the earth were rotating slightly on a third axis we would observe a wobble through its polar axis (which we do), but we cannot tell.
     
  12. Dec 20, 2008 #11
    Might Earth be revolving on infinite axes resolved into one? I defer to Ernst Mach.
     
  13. Feb 8, 2009 #12
    lol Loren!

    " I defer to Ernst Mach. "

    The wit to match the wit. Your quantumdream sure has progressed over the last 5 years.
     
  14. Feb 8, 2009 #13
    netometry,

    I appreciate your taking time for deciphering my site and feedback. You really boost my spirits!
     
  15. Feb 9, 2009 #14

    baywax

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    Thinking outside the...... ellipse? Bravo!
     
  16. Feb 9, 2009 #15
    Don't forget galactic rotation?
     
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