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Refusal to give up absolute

  1. Nov 22, 2004 #1

    Alkatran

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    People refuse to accept that there is no 'rest' frame. Maybe I should just start saying "Well the speed of light is the same for everyone, let's take it's frame" Then I'll fall to the ground yelling "DIVION BY ZERO!!! ARGH!!! ARGH!!!!!"

    All comedy aside:
    Consider a 2d universe on top of a sphere. When someone is moving very quickly up the left side of the shere, would he see events higher up on the right side of the sphere as happening sooner or later than if he weren't moving? (according to our clearly superior rest frame :rolleyes: )

    The problem with this is: Is it only his 2d space which is contracted or the 3d sphere's space?
     
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  3. Nov 22, 2004 #2

    Garth

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    There is no absolute or preferred frame in SR. This insight is carried through into GR with the equivalence principle and the conservaton of four-momentum. However GR introduces masses into the pristine flat SR Minkowski spacetime. Such masses may define a 'preferred frame - that which is co-moving with the Centre of Mass/Momentum.

    You may be interested in the discussion on the thread about the Cosmological Twin Paradox and the preferred frame endowed to observers by the topology of a closed universe here.

    Garth
     
  4. Dec 2, 2004 #3
    Garth - do I take it that you are of the opinion that the non-rotating earth centered reference frame is a preferred frame vis a vis the earths motion through space.
     
  5. Dec 2, 2004 #4

    Garth

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    yogi - IMHO it is that frame co-moving with the centre of mass and momentum of all the matter in the universe, which itself can be identified with the frame co-moving with the surface of last scattering of the CMB in which it is globally isotropic, may be thought of as a 'preferred frame'.

    The cosmological twin paradox highlights its importance as that frame with a 'zero winding number'. That is, if two observers meet in a closed Friedmann universe at two events between which one observer has circumnavigated the universe then one will have measured a longer proper time between these events than the other. The observer in the preferred frame defined by cosmological topology, and therefore the distribution of matter in motion in the whole universe, is the member of the set of all such observers who measures the longest proper time separation between such encounters.

    Garth
     
    Last edited: Dec 2, 2004
  6. Dec 2, 2004 #5

    Aether

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    On Cosmic Clocks

    Special Relativity is based in part on a definition of simultaneity which assumes that there is no such thing as a cosmic clock. If you had a clock that measures cosmic time, then you could compare that to any regular clock that measures proper time, and with a little bit of work you could identify a preferred frame.

    So, how sure are you that there is no such thing as a cosmic clock?
     
  7. Dec 2, 2004 #6

    ZapperZ

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    Say what??!!

    Where exactly is SR based "in part" on the definition of simultaneity? SR is based explicitly on a couple of postulates. It is the consequences of these postulates that there is an issue with "simultaneity". Simultaneity is one of the consequences, NOT the cause, nor the "base". Nowhere in any of these postulates are there any mention of "simultaneity".

    Zz.
     
  8. Dec 2, 2004 #7

    Aether

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    Here Exactly

    Hello Zz,
    In Einstein's 1905 paper On The Electrodynamics of Moving Bodies (which may be found here: http://home.tiscali.nl/physis/HistoricPaper/Historic Papers.html), he makes the following statement: "We have to take into account that all our judgments in which time plays a part are always judgments of simultaneous events". Now, to the extent that one of the postulates of SR that you refer to, namely that "the speed of light c is the same in all inertial frames", applies to "judgements in which time plays a part", then the definition of simultaneity is clearly what is ultimately at issue.
     
  9. Dec 2, 2004 #8

    ZapperZ

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    And he says A LOT more than that too. But it doesn't mean SR is BASED on all that! All you need to do is this: WORK out the formulation of SR, and tell me if at any given point you are forced to assume what a "simultaneous event" is. Just because something is mentioned, it doesn't mean it is based or built on it.

    Zz.
     
  10. Dec 2, 2004 #9

    russ_watters

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    Pretty sure, since all attempts to find it thus far have failed.
     
  11. Dec 2, 2004 #10

    Aether

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    OK, if your argument is with how I'm saying this but not with what I am saying, then please show me how you would phrase what I have said. My point is, Zz, that, contrary to SR, there is a preferred frame in our universe.
     
  12. Dec 2, 2004 #11

    Aether

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    Really? How about the observed mass density of the universe for an example?
     
  13. Dec 2, 2004 #12

    Tom Mattson

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    Speaking for myself: I wouldn't have phrased what you said at all, because what you said is wrong. SR is not based on the denial of a cosmic clock.

    The first postulate says that the speed of light is the same for everyone. In the language of simultaneity, that means that if the emission of a light pulse at x1 is simultaneous with the reading of "t1 seconds" on someone's clock, and the absorption of the pulse at x2 is simultaneous with the reading of "t2" on the same clock, then the quantities will always work out to:

    (x2-x1)/(t2-t1)

    no matter whose clock is used. This, by itself, says nothing about a cosmic clock.

    The second postulate says that the laws of EM (and the laws of mechanics) and are the same in every inertial frame. Again, no explicit or tacit denial of a cosmic clock here.

    It's when you put the two together that you get the prediction of "no cosmic clock". In other words, SR is not based on that idea. Rather, that idea is derived from SR.

    But you have not provided any theoretical or empirical grounds for saying this.

    Mass density is not an example of a clock.
     
  14. Dec 2, 2004 #13

    Aether

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    Based on its two fundamental postulates, SR predicts "no cosmic clock". Thank you Zz, and Tom.

    The observed mass density of the universe is a function of cosmic time. Taking Friedmann's cosmological equations (enter GR) as a first approximation to this function yields one example of a cosmic clock. SR's prediction of "no cosmic clock" fails due to the non-zero mass density of the universe, and therefore something is clearly wrong with either one or both of the fundamental postulates of SR in this context. The door is now open to a preferred frame, and our cosmic clock is useful for identifying this frame.

    Published results from the four-year COBE DMR Cosmic Microwave Background (CMB) Observations http://citebase.eprints.org/cgi-bin/citations?id=oai:arXiv.org:astro-ph/9601067, indicate “… a value for the CMB monopole temperature, T0 =2.725 ± 0.020 K…” and confirm that “The CMB anisotropy is dominated by a dipole term usually attributed to the motion of the solar system with respect to the CMB rest frame…” (e.g., an absolute frame of reference with which to standardize realistic units of space or time). More recently, pre-publication results from the first year Wilkinson Microwave Anisotropy Probe (WMAP) observations http://citebase.eprints.org/cgi-bin/citations?id=oai:arXiv.org:astro-ph/0302207 indicate that “The WMAP-determined dipole is 3.346 ± 0.017 mK in the direction (l,b)=(263.85º ± 0.1º, 48.25º ± 0.04º)”; which is consistent with a solar system β of 1.228(±0.015)E-3.
     
  15. Dec 2, 2004 #14

    ZapperZ

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    Er... hello? You want ME to put words into your mouth so that I can understand what you are trying to say? What kind of a scam is this?

    And since when is physics based on accepting statements of what you or anyone else is saying? Are experimental verifications completely devoid from your consideration? If you think there are contradictions to SR, please cite examples. I, on the other hand, have a zoo of experimental evidence at my disposal. Don't believe me? Check my Journal entries that contains a bunch of published experimental verifications of the postulates of SR and GR.

    Zz.
     
  16. Dec 2, 2004 #15

    ZapperZ

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    I challenge you to contact the authors who published all the papers on CMB results and the WMAP results and ask them if this is exactly what they meant. I will bet you any amount of money that you have bastardized what they are saying because you clearly do NOT understand the basic principles of SR and GR. I have attended several seminars given by people reporting the WMAP results here at Argonne, and in NONE of them have there ever been any declaration of absolute reference frame of any kind! If this is the case, it would have made the headlines in ALL the major physics journals. Yet, where are they?

    You took bit and pieces of snippets of information the very same way the quacks took bits and pieces of understand of "zero point energy" and took off into a completely bogus direction.

    Zz.
     
  17. Dec 2, 2004 #16

    Aether

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    Since your label says "Science Advisor", I thought that you might be willing to gove me some advice.

    Ok, gravity is a contradiction to SR.
     
  18. Dec 2, 2004 #17

    Aether

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    The words absolute reference frame are my own, and they did not come from the authors of those papers on CMB.

    So, which is it Zz?

    I do not doubt the evidence for SR or GR. With respect to SR, I am simply pointing out that it is only valid in the limit as the volume of the space-time element under scrutiny goes to zero. It simply does not apply to the universe as a whole; not by any stretch of the imagination. However, with respect to GR, I do believe that it is an incomplete theory.
     
  19. Dec 2, 2004 #18

    Tom Mattson

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    How's that? "Mass density" is not a Lorentz invariant, so just like time, it is not expected to be the same for all observers. And can you please explain how your argument for cosmic time does not simply presuppose the same? It isn't apparent to me that it doesn't.

    I'll freely admit that my specialty is particle physics and not cosmology. So, could you please supply some backing details to this statement? Mathematical statements would be preferable.

    This is naive. SR's prediction of "flat universe" fails due to the presence of matter in the universe. Guess what? SR is an approximation. But that does not mean that it is to be discarded in the regimes when it is known to be reliable. And there is nothing "wrong" with the postulates of SR. It's just that they need to be supplemented by the postulates of GR to match all of the observational evidence.

    But that's not to say that the predictions of SR don't match a hell of a lot of the observational evidence.

    Sorry, but the simple identification of the limits of applicability of SR is not sufficient to open the door to the negation of SR.

    In the words of the venerable ZapperZ: "Hello?"

    You cannot validly infer that the CMB provides some 'absolute' frame of reference. At least, you have not provided any reason for thinking that you can. Do you have any reasons?

    And you think this means.....?
     
  20. Dec 3, 2004 #19
    SR does not allow for a preferred frame of reference and therefore it does not apply to the Big Bang.

    If you accept the concept that the Big Bang is the starting point of our universe, and there is much evidence to prove that it was, then you must accept the fact that the BB is the prime frame of reference for the entire universe. By every manner of reason the BB is a preferred frame of reference.

    To try and use theories of SR and GR, which only deal with a very small part of the nature of the universe, as a reference eliminates any consideration of the rest of the nature of the universe. This is why no connection of gravity to the other forces has been made and no connection to QM is possible.

    All observation requires that the BB happen about 15 billion years ago and the universe changed in that time to the universe we see today. All logic requires the acceptance that a transition of the universe took place from the BB to the universe of today. The only question is the nature of the transition.

    The nature of the transition of the BB is the starting point and reference for all other frames of reference.

    To deny the reality of transition outward from the BB is not logical or productive.
     
  21. Dec 3, 2004 #20
    All of the experimental results that are cited to support SR are also consistent with LR (Lorentz Relativity), and MLET (modified Lorentz Ether Theory), Non rotating earth center as a preferred frame, and a frame that has zero velocity with respect to the CBR (a point and velocity where the CBR is isotropic). All experiments that confirm the Lorentz transforms are also consistent with Selleri transforms, and some other cosmological theories. Most of the alternative theories are based upon one of the above preferred reference frames and they all predict the same results as SR. So until there are experiments that fasify these alternative explanations in favor of SR, why be so certain that SR is any more correct than any other theory that gets to the same result vis a vis a preferred reference frame.
     
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