What is a reference frame?

Discussion in 'Physics & Math' started by James R, Oct 13, 2004.

  1. Quantum Quack Life's a tease... Valued Senior Member

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    it really comes down to a simple question:

    If the Non-rest frame is not simultaneous from it's perspective then where oh where does it locate itself relative to the rest frame when it deems itself at rest?
    It obviously can't be where the other frame thinks it is, so where is it?
     
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  3. fo3 acdcrocks Registered Senior Member

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    It should locate itself closer to the other frame, then the other frame locates it. γ times closer, i assume.

    And in the same time, the other frame sees it closer, then it is in reality, also, since it takes time for the information to reach the other frame? I don't really understand all this Now argumenting, so I'm not able to tell, what this means.
     
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  5. Yuriy Registered Senior Member

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    QQ,
    Show us where, when and how "SRT of course says otherwise", i. e. that "for two objects to collide in the usual physical sense their NOWS have not to be simultaneous". Show us where, when and how SRT says that "one object can collide with the past of another object" and that "of course the other object hasn't experienced that collision...... ".
    Little by little you become the most ignorant corrupter of SRT in our Forum...
     
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  7. Quantum Quack Life's a tease... Valued Senior Member

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    So Yuriy the NOWs are simultaneous, regardless of velocity, yes or No?
     
  8. Quantum Quack Life's a tease... Valued Senior Member

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    or maybe I should ask a more basic question:
    How would you define the "NOW"?
     
  9. Yuriy Registered Senior Member

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    QQ,
    First of all (before you will have a moral right to ask any new question in this discussion), you should show us where, when and how SRT says that "one object can collide with the past of another object" and that "of course the other object hasn't experienced that collision...... ".
    So, show us that...
     
  10. Quantum Quack Life's a tease... Valued Senior Member

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    Firstly Yuriy, I have never said that SRT states this, I have ASKED that if SRT maintains that the NOWs are not simultaneous that this could be an outcome of such logic.

    Secondly, Yuiry it appears that the very center of SRT reasoning is time or should I say relative time, yet it seems to be the least understood, which is what I wish to clarify.

    Thirdly, Yuiry, not once has any one in 2 yeasr fully explained how dilated time effects the NOW of an object at velocity, and indirectly claim simultaneousness of the NOW's whilst argueing that they are non-simultaneous.
    For this forum it is a new concept to realise that a frame when demed at rest is also in its NOW in time. And I am proposing that if this the case then it's NOW location is different to what the other frame deeems it to be as SUGGESTED by SRT.

    SO therefore my statement:

    which leads on to the following question:

    Obviously if I was not ignorant of the answer I wouldn't be asking the question.

    As to my MORAL right, I fail to see where morality has anything to do with my ignorance of the answer.
    It is my moral right to ask questions and seek answers in any way I see fit.

    Your theory of SRT is on a pedastal of your creation and is not mine. I understand that you will defend your worship of SRT to the hilt, and expose your own inability to open your eyes to other ideas, whether valid or not.
    But it is not my job to open your eyes as all I want is to keep mine open and not waste my time tryng to open yours.

    I see a problem with simultaneousness as per SRT and that is what I am exploring in my ignorant way.

    The logic isn't hard to see whether the premise is valid or not. if the premise is not valid then I stand corrected. But only if my understanding of SRT is invalid. [Which I am sure you think it is but are reluctant to discuss in what way, in a way that is successful to you, me and others]

    I know from past experience that SRT exponents will always resort to the issue of non-simultaneousness in their final defence of SRT and it amazes me that the concept of time is so badly understood.

    I get the impression that SRT [or should I say, the understanding of SRT] defeats itself if one looks closley at this issue.

    Simultaneousness to me is defined as saying that two events occur at exactly the same time. [world time line] Not just IN the SAME time but AT the SAME time.

    If events do not occur at the same time in this context means that the events are no longer simultaneous. Thus one event occurs is in the past of the other event. The question is : "How far into the events past did the other event occur?
    And given that the object has velocity then the location of that event in it's NOW is also determined by that difference in events postion in time.
     
    Last edited: Jan 15, 2005
  11. Quantum Quack Life's a tease... Valued Senior Member

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    And BTW I really can't see how I can make my idea any clearer. If you don't understand what I am attempting to describe then quite simply I have failed to communicate it effectively.

    But please don't accuse me of deliberately and with malicious intent, attempting to undermine or conspire to in some way discredit you, SRT or anyone else. As this is definitely NOT the case.
    As part of my research into other fields the veracity or not of SRT is very important and this is what I am about with regards to the reasoning in use.
     
  12. Yuriy Registered Senior Member

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    QQ,
    I still can not determine my opinion about you, because every time I read your post I feel that I deal with … two people. One is very logical and careful in his research and expressions, and another one is … like MacM. One of them is able to see and emphasize the most sensitive and problematic aspects of SRT, demonstrating a deep apprehension of this fundamental theory, and another one reveals … a total misunderstanding and even ignorance of its very basic issues. It is something wrong in this picture and I know what is responsible for this strange dualism. It is your systematic neglecting of the basic scientific terminology, basic rules of expression of the basic notions and … some strange manner (or hubby?) to substitute usual conventional terms by the nova-creations.
    Indeed, let me go through some of your thoughts in the last your post.

    1. “Secondly, Yuiry it appears that the very center of SRT reasoning is time or should I say relative time, yet it seems to be the least understood, which is what I wish to clarify”.

    You feel that the phenpmenon of time plays a central role in whole SRT. It is good and it is right. But why you are using some strange word “reasoning” in this context? Like you already prepare the place to strike SRT in its most sensitive part… And you do it further: you are not clarifying anything (and even actually do not wish anything to be clarified), but striking, not explaining any appearing “problems”, but make conclusion: “Aha, there is a problem and that means that SRT is wrong, at least, partially”. This is seen through all your posts on SRT…

    2. “Thirdly, Yuiry, not once has any one in 2 yeasr fully explained how dilated time effects the NOW of an object at velocity, and indirectly claim simultaneousness of the NOW's whilst argueing that they are non-simultaneous.
    For this forum it is a new concept to realise that a frame when demed at rest is also in its NOW in time. And I am proposing that if this the case then it's NOW location is different to what the other frame deeems it to be as SUGGESTED by SRT
    .”

    Let’s analyze this mess of words.
    First of all what people failed to fully explain in 2 years. The “dilated time”? What it is? You can not divide a time on two parts and say this is “a dilated one” and this is “a non-dilated one”. Time is time. Every observer of Nature measures it by his clocks, observes it due to processes he is watching and monitoring, and so on. Nobody feels time as dilated or accelerated. Time dilation can be and actually is revealing only in comparison of its measuring in two (at least) references frames (RF). Without this comparison there is no time dilation, at all! You systematically neglect this fundamental attribute of the natural time. When it does MacM, we all already know why, but you? Why you are doing that?
    But let us go further. Why this mysterious "dilated time" should effect NOW? And what is “object at velocity”? An object that moves in respect to us? If so, man, why you do not say “at moving object”?
    Who “indirectly claim simultaneousness of the NOW's”, what NOW’s? Why “whilst argueing that they are non-simultaneous” if “claim simultaneousness of the NOW’s”?

    NOW plays a fundamental role in whole Physics (you will see it in my book on SRT soon), but its definition is very simple: NOW of any observer is the whole World, with all things and all events that happened to be at the current moment of time. His/her time, not some other observer’s one, or some mystic “Absolute time”.

    And now explain us what means your statement : “For this forum it is a new concept to realise that a frame when demed at rest is also in its NOW in time”. What we have missed accepting the obvious definition of NOW, I just gave you?

    3. “And I am proposing that if this the case then it's NOW location is different to what the other frame deeems it to be as SUGGESTED by SRT.” Here you go to attack SRT! But it is false accusation of SRT: SRT never “SUGGESTED” that.

    The problem of simultaneousness of two events in SRT is very clear and obvious one: I wrote about it in this Forum many times.

    Let we have two events of Nature, event A and event B. There are two fundamental physical characteristics attributed to each of them in any RF: position, where event is happening, and moment of time, when event is happening. So, A = A(Xa, Ta) and B = B(Xb, Tb). Of course, each observer attributes each of those events (the same events of Nature, A and B!) with his/her own position and moment of time, measured in his/her RF.
    Therefore, if in one RF it is A = A(Xa, Ta) and B = B(Xb, Tb), than in another RF it will be A = A(Xa’, Ta’) and B = B(Xb’, Tb’).

    All this has noting to do with SRT: it is common concept for any physical theory: so it was in Newtonian Physics, so it is in SRT, and so it will be in any other physical theory.

    The specific of SRT comes after the Lorentz transformations that are the logical consequence of the Postulate of the absoluteness of the speed of light in vacuum. They state that the relations of {(Xa, Ta), (Xb, Tb)} with each other is:

    Xa’ = G(u)(Xa – uTa) and Ta’ = G(u)(Ta – uXa/c^2) …………………..(*)
    and
    Xb’ = G(u)(Xb – uTb) and Tb’ = G(u)(Tb – uXb/c^2) …………………..(**)

    where G(u) =1/(1-u^2/c^2)^1/2 and u is the speed of second Rf in respect to the first one (it is assumed that RF moves along axis X and that clocks of both RF are synchronized at the coincidence of the origins of both RF).

    To analyze the problem of simultaneousness in SRT, all you need is (*) and (**).

    If events A and B are happened simultaneously in the two different places in one RF, let us say at Ta = Tb in Xa and Xb in the first RF, then at any u they can happen also simultaneously in the second RF only and only if in the first one we have Xa = Xb. Indeed, as (*) and (**) show, at Ta=Tb we will have Ta’=Tb’ only and only if Xa = Xb. So, any two events that were happened simultaneously in the one RF in two different places CAN NOT HAPPEN ALSO SIMULTENEOUSLY IN ANY OTHER RF.

    In contrary, if Xa = Xb and Ta = Tb then Xa’ = Xb’ and Ta’ = Tb’ at any u. This is why I called your assertion that “SRT of course says otherwise, one object can collide with the past of another object” as your fantasies! No object can collide with any Past or Future of any other object! SRT stays upon that and saying opposite is a false accusations of SRT…

    And so on, and so one in all your posts with accusations of SRT, my friend…
     
    Last edited: Jan 15, 2005
  13. MacM Registered Senior Member

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    Before coming over here and interjecting my name in vain with BS, let me suggest you show you know anything at all and respond scientifically to the question I have raised [thread=44130]Here[/thread] rather than dancing around false innuendo and slander.
     
  14. Quantum Quack Life's a tease... Valued Senior Member

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    The problem I have with this is you seem to be missing the other attribute being the objects movement or relative velocity.
    In the above assessment where does velocity play it's part in these two events of Nature?
     
  15. Quantum Quack Life's a tease... Valued Senior Member

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    Yuiry I deleted the post I made becasue I failed to read your last post properly. Also my previous post immediately above also was incorrect but I will let it stand as an example of my rash judgement.
     
  16. Quantum Quack Life's a tease... Valued Senior Member

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    Firstly let me apologize for assuming that you would go on posting with out addressing the issue and in some ways I note that you have and therefore I apologize for my premature assumption.

    Secondly as I attempt to understand the logic of what you have written I have a question to ask in teh mean time:

    You have stated:

    My interpretation:
    This assumes that the situation has a begining in time and that the clocks are synchronized at this beginning.
    The question comes to mind that if there is no initial synchronisation what basis is used to account for the degree of non-simultaneousness?

    Say for an extreme example a comet that has been traveling at relative to Earth velocity for a million years. How would one estimate it's relative age to that of Earth. Assuming no ability to synchronise hypothetical clocks.

    And if we assume an age difference can this only be done by assuming also simultaneous nows of that comet and the Earth. Otherwise the age difference looses relevance?
     
    Last edited: Jan 15, 2005
  17. Yuriy Registered Senior Member

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    This your post is a best proof of what I said about you in my previous one: we deal with two people in … you.

    1. So, you still do not know what means the fundamental procedure of the synchronization of clocks before you start comparing its readings? Any theory of Relativity starts from this point of consideration.

    Synchronization of clocks means putting their readings (arrows, counter of seconds, etc) on the same positions (numbers on clock-faces, number of face of counter, etc) simultaneously in some of the reference frames. Usually this initial moment – the start of readings – is chosen as the zero of readings (the beginning of readings).

    2. The procedure of synchronization of clocks has nothing to do with … physical “beginning of a time”.
    3. If clocks of Earth and comet never were synchronized, you never will know comets actual age. That is why physics starts with synchronization of clocks. If we can not do that physically, we do an investigation of the actual age of things due to analyzing of the different processes and accumulated features of comet or any other considered body.
     
    Last edited: Jan 15, 2005
  18. Quantum Quack Life's a tease... Valued Senior Member

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    I think this diagram shows what it is I wish to come to understand.
    There are two NOW [event] concepts shown, and I have a feeling that neither show the SRT position.

    The grey bars indicate the length of a second of time. The question is which diagram shows the SRT position regarding the NOW event of each RF.

    <img src=http://www.paygency.com/Diagrams/relativenow.jpg>

    If Yuiry you could indicate which diagram is indicative of SRT I would appreciate it.
    Diagram 1,
    Diagram 2
    or
    Neither....

    Thanks
     
  19. Yuriy Registered Senior Member

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    QQ,
    I repeat this specially for you for the last time:
    1. NOW for any observer is not an event, but set of all events that are occurring and existing in some given moment t shown on the observer's (let say - observer A) clock. So, each NOW should be accompanied by some mark like the moment of time, or words like "just when this pistol did shoot". In other words, NOW(t|A) is the NOW that happened (happens, is realized, exist, etc) at moment t measured by this observer A.

    2. Because NOW(t|A) for some observer A is set of events, it is Lorentz-invariant notion: any observer will tell you the same of what events of Nature are included into the set NOW(t|A). In other words, any observer exactly knows what NOW of any other observer is at any moment of time.

    3. If two observers in different RF are talking about their NOW-s connected with some two events that happened for both of them simultaneously (like collision of particles e and p), then these NOW-s are consisting of all the same events - all events in Nature that happened simultaneously with collision of those physical particles, e and p.

    So, stop wasting your time and attention of people of our Forum to drawing and watching diagrams, which even you can not explain... Best what you can do is to cogitate on what I just said and try to develop it in your head... I will not answer you anymore on any questions about NOW-s, if you will not speak in terms and definitions I just gave you...
     
    Last edited: Jan 19, 2005
  20. Quantum Quack Life's a tease... Valued Senior Member

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    Yuiry, I may be uneducated in the language of physics, and I may offer some pretty wierd ways of looking at things but I am not an arrogant arsehole, who can not see the forrest for the trees.
    It is obvious that in all our communications now and in the past that we are unable to communicate in any meaningful way. So I withdraw any questions outstanding including my last one and accept that there is no hope in achieving anything worth while by continued discussion with you.

    Maybe one day we willlearn to speak the same language and enjoy further discussion but until then ...........take care

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  21. fo3 acdcrocks Registered Senior Member

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    So, if there are two reference frames, then if the collision of particles happens simultaneously in both frames, then all the other events in the frames happen simultaneously also, in that moment?
     
  22. Ophiolite Valued Senior Member

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    Damn. I enjoyed the exchanges.

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  23. Yuriy Registered Senior Member

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    fo3,
    exactly!
     

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