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Does time dilation occur even without a point of reference to measure motion?

  1. May 24, 2004 #1
    Help shed some light on this question please.

    It is my understanding that organisms age faster at the North Pole relative to organisms at the equator. And organisms at the equator age slower relative to organisms at the north pole. An experiment I head of that measured these effects was similar to putting one atomic clock on the center of a record player and another at the edge of the record player and recording the difference of their clocks.

    I assume we know the North Pole is moving slower than the equator because of observations of the North Pole and equator relative to points of references such as the Sun, distant stars, CMBR, etc.

    My question is this… if we took away all of our points of references would these time dilation effects at the north pole relative to the equator still take effect? Imagine if we enclosed the Earth in a HUGE metal sphere where we could no longer see any points of references that we currently use to determine the orbital and rotational motions of the Earth…would organisms still age slower at the North Pole?

    Thank you,

    (edited) There is probably a hundred reasons why a huge metal sphere enclosing the Earth would not take away all of our points of references... but forgetting about that... if it was possible to take away all of our points of references to measure the Earths rotation would time dilation sill occur at the North Pole relative to the equator...
    Last edited: May 24, 2004
  2. jcsd
  3. May 24, 2004 #2


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    Where in the world did you get that understanding? The difference in speeds between the north pole and the equator is nowhere near the speed of light and any time contraction effects are unmeasureably small.

    Are you only referring to points of reference off the earth? The point of time contraction is that one reference frame has to be moving relative to the other. IF the difference in speeds at the north pole and equator were large enough to be of any importance, you would still measure them relative to one another, not relative to any point in space.
    Last edited by a moderator: May 24, 2004
  4. May 24, 2004 #3
    I've read about it a few times, saw a show last night called "Ascent of Man" that reminded me about it, and just did a quick search on the Net and found many articles talking about clock differences between the North Pole and Equator, here are some links 1) http://www.physics.nus.edu.sg/~physowch/teaching/SFM/22 [Broken] 2) http://www.jnocook.net/work/choi/einstein.htm [Broken] 3) http://www.newphys.se/elektromagnum/physics/Tedenstig/own/einein.html

    I didn't read these articles listed; I’m just showing some search results from the words (time dilation differences north pole equator) to let you know "where in the world" I got this understanding. I got it from different shows, books, and articles. I certainly didn’t fabricate the idea.

    I understand the speed difference between the North Pole and the Equator is no where near the speed of light. But I did think time contraction effects between the equator and North Pole were measurable because the shows and articles I have seen allude to it. But you replied that they are "ummeasurably small." I respect your knowledge because I see you intelligently responding to many posts on this board. However, being a little skeptical here,... Are time contraction effects between the North Pole and Equator indeed so small that they can not be measured?

    This is where I am mixed up I bet. Yes I was referring to points of references off of the Earth, because I didn't realize you could tell that the Earth was rotating if you didn't have things like the Sun as a reference points.

    How can you tell that the Earth is rotating without observing objects off of the Earth?

    Thanks again,
    Last edited by a moderator: May 1, 2017
  5. May 24, 2004 #4


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    "How can you tell that the Earth is rotating without observing objects off of the Earth?"

    Foucault's pendulum
  6. May 24, 2004 #5


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    The first of those three links didn't work. The second talks about measuring differences in atomic clocks- not quite the same thing as "animals aging slower" but I will accept that it is (if you work really, really accurately) measurable. The third link is a crank site arguing that the theory of relativity is wrong.
  7. May 24, 2004 #6
    There is no change, but not because the speeds are so small. It turns out that the earth is an oblate spheroid because of its rotation, and the change in the gravitational redshift from the deviation in r cancels out the time dilation from rotational speed. Ideal clocks on the geoid (basically the idealized sea level) all tick at the same rate - you don't have to adjust for latitude. Just altitude, for the gravitational redshift, of about a part in 1016 per meter.
  8. May 25, 2004 #7


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    Why do you people always talk about Atomic clocks. Atomic clocks are only for accurate measures of time. If it affects an atomic clock, it affects everything else.

    Just because something isn't going a phenomenal speed, is does not mean it doesn't get affected by relativity. The changes might be small, but they shouldn't be ignored. That's like ignoring anything on the Atomic Scale just because you can't measure it with a ruler or "see" it.

    You have to stop making benchmarks.
  9. May 25, 2004 #8
    But if you can't measure it with the most sensitive instrument you've got, you aren't going to notice it elsewhere.
  10. May 25, 2004 #9


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    Plus, that's the only way to quantify it. Its not generally something you would qualitatively observe.
  11. May 25, 2004 #10

    Chi Meson

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    Further explanation:

    Even if there was nothing else to measure the motion of the earth by, the spinning earth would require that all objects on its surface undergo centripetal acceleration. What Foucault's pendulum is able to detect is the fact that it is accelerating.
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