Thread: Is time universal? NO (and its proof)

  1. #381
    Pete's notepad example is instructive.

    Clock times stamped on notepads are unambiguous records of clock readings at the time and place of the stamping.

    If you run past me holding a note pad, and at the instant you're level with me I reach out and stamp the current time displayed on my watch onto your pad, then you have an unambiguous reading from my watch.

    Suppose on the other side of the pad you record the time on your watch at the exact instant I stamp your pad. Suppose you then run off, and after running around in circles for a while you run past me again. Again, I stamp your pad and you write down the time on your watch on the other side. Now you can calculate the differences in accumulated time between our two meetings, as indicated on your watch and on my watch. You have a permanent record which we both agree on.

    There are no problems with simultaneity here, since both marks on the pad at the two times are made at the same spatial location. An argument cannot be made that I did not make make stamp simultaneously to your writing on the back of the pad, in either your frame or in my frame. In general, if events A and B occur in the same location at the same time according to one observer, they MUST occur at the same time according to every other observer, regardless of their state of motion.

    MacM says above that this is exactly like his argument for "real clock time", but it isn't. Why not? Because in his examples, MacM often compares times as recorded on clock at different spatial locations. In that case, the relativity of simultaneity is very important indeed. If I write on my pad, and you write on yours, how can we guarantee that just because those two events happened at the same time according to my watch, they also happen at the same time according to your watch, when they happened in different places? Answer: we can't.

  2. #382
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    I think the point that is lost on everyone is that within the framework of special relativity, there is a shift in simultaneity for any noninertial frame. However, in the framework of local ether theory, there is no shift in simultaneity. In special relativity, any instantaneous frame sees another frame's clock as dilated. In local ether theory, dilations are absolute (as in, they are all the same) in all frames relative to the local ether. There is no length contraction in the local ether model for relative motion with respect to the local ether frame.

    The two are very distinct theories yet give the same result if you assume the local ether frame to be the only rest frame.

  3. #383
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    James R: get back into reality. When times are compared in GPS, the comparison is not at the same spatial location as I am not required to launch up into space to each satellite so that my GPS device can take a reading

    We are of course suppose to be talking about the dilation calculation which is neither in the satellite frame or the ground frame. It is always calculated in the so-called "local ether frame".

  4. #384
    Registered Senior Member MacM's Avatar
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    Quote Originally Posted by James R
    Pete's notepad example is instructive.

    Clock times stamped on notepads are unambiguous records of clock readings at the time and place of the stamping.

    If you run past me holding a note pad, and at the instant you're level with me I reach out and stamp the current time displayed on my watch onto your pad, then you have an unambiguous reading from my watch.

    Suppose on the other side of the pad you record the time on your watch at the exact instant I stamp your pad. Suppose you then run off, and after running around in circles for a while you run past me again. Again, I stamp your pad and you write down the time on your watch on the other side. Now you can calculate the differences in accumulated time between our two meetings, as indicated on your watch and on my watch. You have a permanent record which we both agree on.

    There are no problems with simultaneity here, since both marks on the pad at the two times are made at the same spatial location. An argument cannot be made that I did not make make stamp simultaneously to your writing on the back of the pad, in either your frame or in my frame. In general, if events A and B occur in the same location at the same time according to one observer, they MUST occur at the same time according to every other observer, regardless of their state of motion.
    Absolutely agree.

    MacM says above that this is exactly like his argument for "real clock time", but it isn't. Why not? Because in his examples, MacM often compares times as recorded on clock at different spatial locations. In that case, the relativity of simultaneity is very important indeed. If I write on my pad, and you write on yours, how can we guarantee that just because those two events happened at the same time according to my watch, they also happen at the same time according to your watch, when they happened in different places? Answer: we can't.
    Do not agree. Yes it is different but my discertation about tick rates achieves the same principle. Or do you deny my presentation with any specific rebuttal or shall it just be the typical blow off as 1100f has just tried to pull.

  5. #385
    Aer:

    That post was partly for your benefit, since in an earlier response to Pete, you were arguing that relativity-of-simultaneity effects were important even at the same location.

    Now you know why you were wrong.

  6. #386
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    Quote Originally Posted by James R
    That post was partly for your benefit, since in an earlier response to Pete, you were arguing that relativity-of-simultaneity effects were important even at the same location.

    Now you know why you were wrong.
    No. We were talking about the calculations of the actual time dilated between two frames:

    Quote Originally Posted by Aer
    Quote Originally Posted by Pete
    That gives √(1-v˛/c˛) = 0.9999999999168
    Multiply that by 86400 seconds in a day, and we find that SR predicts the satellite clock ticks 86399.9999928 seconds for each 86400 second day on the ground clock, or 7.2 microseconds short.

    This is not frame dependent. SR says that it's true in all frames.
    SR does not say it is true in all frames. It is only true in the frame you calculated it in (ECI). All other frames will give a different value.
    Quote Originally Posted by Aer
    Quote Originally Posted by Pete
    Quote Originally Posted by Aer
    SR does not say it is true in all frames. It is only true in the frame you calculated it in (ECI). All other frames will give a different value.
    So you say... what's your response to this post?
    ...
    Do you agree that the writing on the notepads is an unambiguous record of the readings of the clocks each time they pass each other?
    It is not unambiguous because of the relativity of simultaneity inherent in special relativity.
    And what I said is correct, because the actual time dilation in various frames (the source topic) is different in every frame because of the relativity of simultaneity. You just didn't understand the entire meaning of the problem.

    This debate has always been about the time dilation calculation. This is different in every frame of reference for the reason I stated: the relativity of simultaneity.

  7. #387
    Quote Originally Posted by MacM
    You seem to be wasting ours since you have no rebuttal of my position.
    It appeard that you are the one that waste our time wuth the things that you say about relativity since you have shown that the simplest exercise in SR is beyond your capacity.

  8. #388
    Registered Senior Member MacM's Avatar
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    Quote Originally Posted by Aer
    No. We were talking about the calculations of the actual time dilated between two frames:

    And what I said is correct, because the actual time dilation in various frames (the source topic) is different in every frame because of the relativity of simultaneity. You just didn't understand the entire meaning of the problem.

    This debate has always been about the time dilation calculation. This is different in every frame of reference for the reason I stated: the relativity of simultaneity.
    It should be pointed out that what is fixed is the tick rate of the orbiting clock. What changes is the 86400 tick referance view of some other frame than a stationary one.

  9. #389
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    Quote Originally Posted by 1100f
    It appeard that you are the one that waste our time wuth the things that you say about relativity since you have shown that the simplest exercise in SR is beyond your capacity.
    To be fair, I challenged MacM to actually do SR problems in the past in which he was successfully able to complete. Some of his ideas are what I would label as "incomplete" and therefore don't really make sense, but for the most part he seems to be in agreement with the local ether model of wave propogation which has been introduced by others in academia

  10. #390
    Quote Originally Posted by Aer
    To be fair, I challenged MacM to actually do SR problems in the past in which he was successfully able to complete. Some of his ideas are what I would label as "incomplete" and therefore don't really make sense, but for the most part he seems to be in agreement with the local ether model of wave propogation which has been introduced by others in academia
    I guess you and me are living on different planets

  11. #391
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    I guess you and me are living on different planets
    Was quite shocked myself

  12. #392
    Valued Senior Member Neddy Bate's Avatar
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    Quote Originally Posted by James R
    Pete's notepad example is instructive.

    Clock times stamped on notepads are unambiguous records of clock readings at the time and place of the stamping.

    If you run past me holding a note pad, and at the instant you're level with me I reach out and stamp the current time displayed on my watch onto your pad, then you have an unambiguous reading from my watch.

    Suppose on the other side of the pad you record the time on your watch at the exact instant I stamp your pad. Suppose you then run off, and after running around in circles for a while you run past me again. Again, I stamp your pad and you write down the time on your watch on the other side. Now you can calculate the differences in accumulated time between our two meetings, as indicated on your watch and on my watch. You have a permanent record which we both agree on.

    There are no problems with simultaneity here, since both marks on the pad at the two times are made at the same spatial location. An argument cannot be made that I did not make make stamp simultaneously to your writing on the back of the pad, in either your frame or in my frame. In general, if events A and B occur in the same location at the same time according to one observer, they MUST occur at the same time according to every other observer, regardless of their state of motion.
    James' above comments about "notepads" has inspired me to try this: "Is time universal? YES (and its proof)".

    Let us imagine a surveillance system of notepads evenly distributed throughout an inertial frame of reference, K. The entire system is of notebook clocks is synchronized so that all notepads are gathering information "simultaneously" in that frame. In other words, all of the clocks in K always show the exact same time (factoring out all perception-delay effects due to c being finite).

    A second, identical 'surveillance system' co-exists for a different inertial frame of reference, K'. The velocity of the uniform translational motion between the two systems is v.

    Whenever a notepad in K passes very near (disallowing collisions) a notepad in K', they collaborate and print one receipt of all of the available information about the current time and location of each coordinate in each of the two systems.

    Assuming these Cartesian systems represent our universe (something which KitNyx suggested previously in this thread miight not be the case), then we can come to no other conclusion except a concept of universal time. In fairness to Aer, who refuted KitNyx's objection to the Cartesian system, I cannot envision any system, Cartesian or otherwise, in which the notebooks could read two different ways, and still conform the James' contention that the notebooks are synchronized as they pass very near each other at v (disallowing collisions).

  13. #393
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    Neddy Bate, it appears that you have discovered the nonsensical nature of the relativity of simultaneity that I've claimed for, well... ever. If one is to believe most of the clowns around here - physics need not make sense! I give them the benefit of the doubt on this, but I will not believe them when they try to convince me that current theory is "correct".

  14. #394
    Neddy Bate:

    What you have discovered is that everybody in two frames will agree unambiguously on what clocks in the two frames read at any particular location, provided all clocks in one frame are synchronised with each other, and all clocks in the other frame are synchronised with each other.

    What you need to be careful about is to assert that therefore the clocks in one frame remain synchronised at all times with clocks in the other frame, because that does not happen.

  15. #395
    Aer:

    You missed the point again.

    Quote Originally Posted by Aer
    Quote Originally Posted by Pete
    Do you agree that the writing on the notepads is an unambiguous record of the readings of the clocks each time they pass each other?
    It is not unambiguous because of the relativity of simultaneity inherent in special relativity.
    The only way you can claim that is if you believe that the actual writings on the papers change so they are different for different observers.

    That is not what happens according to relativity, and it certainly seems like nonsense to me, so I'd be interested in how you attempt to justify it.

    And what I said is correct, because the actual time dilation in various frames (the source topic) is different in every frame because of the relativity of simultaneity.
    I agree that time dilation is different in different frames, but due to velocity, not relativity of simultaneity. I think you are confusing the two things.

  16. #396
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    Quote Originally Posted by James R
    Aer:

    You missed the point again.
    No, you missed the point. Pete is suggesting that the elapsed dilated time is the same in all frames. That is not the case. Each frame will measure time dilation different for the two satellites. You are only picking up one part of the problem and ignoring the portion of the problem that I was talking about and responding to. Here it is again:
    Quote Originally Posted by Aer
    Quote Originally Posted by Pete
    That gives √(1-v˛/c˛) = 0.9999999999168
    Multiply that by 86400 seconds in a day, and we find that SR predicts the satellite clock ticks 86399.9999928 seconds for each 86400 second day on the ground clock, or 7.2 microseconds short.

    This is not frame dependent. SR says that it's true in all frames.
    SR does not say it is true in all frames. It is only true in the frame you calculated it in (ECI). All other frames will give a different value.

  17. #397
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    Quote Originally Posted by James R
    What you need to be careful about is to assert that therefore the clocks in one frame remain synchronised at all times with clocks in the other frame, because that does not happen.
    Neddy Bate did not assume any clocks were synchronised in any other frame than clocks that are in the same frame. You need to reread his post.

    Think of it this way: On the x-axis you have a clock at each coordinate, 0, 1, 2, 3, 4, 5, 6, etc. These clocks are all synchronised and stay at rest in frame K.

    Then you have a clock that moves along the x axis at a relativistic velocity such that it is at rest in an inertial frame K'. Each time the moving clock passes a clock on the x-axis, they exchange their information. There is no assumption that any clock at rest in frame K is synchronized with the clock at rest in frame K'.

    I am curious, with velocity v=.9c, what do you predict the exchanged information will be at each coordinate 0-5.
    Last edited by Aer; 10-12-05 at 02:36 AM.

  18. #398
    Good question, Aer.

    Let's take a clock moving at 0.9c. Let that clock start from x=0 at time t=t'=0, moving along the positive x axis. Suppose the axis is marked off so that x=1 corresponds to 1 light second, x=2 corresponds to 2 light seconds from the origin, etc.

    After the clock has passed x=6, we look at what is written on the notepads attached at x=0,1,2,3,4,5,6.

    The recorded times on on the two sides of each piece of note paper are:

    Code:
    x       t(s)        t'(s)
    0     0      0
    1     1.11  0.484
    2     2.22  0.968
    3     3.33  1.452
    4     4.44  1.936
    5     5.55  2.420
    6     6.66  2.904
    Now, I say that it doesn't matter whether the stationary observer collects the papers and looks at them, or if the moving observer collects the papers and looks at them. The numbers will be as I have written, and both observers will agree on that.

    Do you agree? Because your previous posts seem to say youi disagree.

  19. #399
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    So you are suggesting to me that the moving observer (always in an inertial frame) agrees that his clock is dilated from the perspective of his rest frame? That is what your notepad readings suggest.

    Is this what you think would happen or is this what special relativity says happens?

  20. #400
    Quote Originally Posted by Aer
    So you are suggesting to me that the moving observer (always in an inertial frame) agrees that his clock is dilated from the perspective of his rest frame? That is what your notepad readings suggest.
    How do you figure that?
    Do you agree that the given notepad readings are as predicted by SR or not?
    Do you agree that according to SR both observers agree on those readings or not?

    I've checked James' figures (have you?), and they check out except for some slight rounding errors.
    I make the figures to be:
    Code:
    x       t(s)      t'(s)
    0      0         0
    1      1.11     0.484
    2      2.22     0.968
    3      3.33     1.453
    4      4.44     1.937
    5      5.56     2.422
    6      6.67     2.906
    Be sure to check that the readings are consistent in the moving frame... but be sure to transform events properly and be careful of your assumptions. It's easy to assume absolute time if you try to take shortcuts.

    Don't forget that in the example given, we have one moving clock and seven stationary clocks. To properly check consistency, you might like to expand the example and add some more moving clocks.
    Last edited by Pete; 10-12-05 at 05:29 AM.

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