Can the Twin Paradox be simplified?

Discussion in 'Physics & Math' started by timewarp, Nov 20, 2011.

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  1. timewarp Registered Member

    Is would be nice to eliminate the following from the Twin Paradox:

    1. Acceleration
    2. Clock synchronization
    3. Reciprocal Geometric effects
    4. Optical Doppler effects
    5. Relative simultaneity
    6. History problems
    7. Asymmetries
    8. Lorentz transformation

    It seems to me that by eliminating some or all of these things, we
    can have a better chance of seeing what is really happening.

    Oddly enough, we can simplify the Twin Paradox by adding a third
    person, and this addition will completely eliminate all but one of
    the above items (item 6).

    This Triplet Version is not my idea, but comes from a respected
    "relativist" and mathematician (by the name of Wayne Throop).

    Although he used three people, we need to use three clocks in order
    to eliminate item 6. (Clocks can be instantly made to read any time
    upon starting.)

    Here is the Triplet Case with clocks:
    [clocks and their time readings are in brackets]

    Inertial-moving clocks A and B meet in passing when they both read

    Clock B moves to the right at speed .6c wrt Clock A


    Clock B meets Clock C, which is made to copy B:

    C is moving in the opposite direction at .6c wrt A

    C finally catches up with A

    Switching back to people (because we can all relate to people
    much better than we can relate to clocks), we see that Ann (as
    Clock A) is older than Carl (or Clock C).

    Physical aging is an intrinsic phenomenon, and must have a
    physical cause. This means that a difference in ages for those
    who were born at the same time (such as triplets) must also
    have a physical cause.

    Ann could have been a grandmother while Carl was still a shy
    teenager, but there were no accelerations and no Einsteinian

    This raises the question Why do people in different frames age

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  3. AlphaNumeric Fully ionized Moderator

    So you want to remove relevant things?Asymmetric and acceleration and Loremtz transforms formthe core of the whole thought experiment. Asymmetry is the answer to your question!
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  5. James R Just this guy, you know? Staff Member

    Scenarios have been constructed in which acceleration is not required.

    I'm not sure what you mean by that. In the twin paradox, there are only two clocks and they are not synchronised.

    What are those?

    No version of the twin paradox I have ever seen has considered those.

    If you pretend that the relativity of simultaneity doesn't exist, then you'll get the wrong answer for the twin paradox. You can't just leave out relevant physics.

    Such as?

    If there's no asymmetry at some point, then there'll be no difference in twin ages, either.

    How can you do relativity without a Lorentz transformation?
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  7. timewarp Registered Member

    If you don't know about an item, or if you don't care about an item,
    then don't worry about it. But I have seen many "explanations" of
    the Triplet Case, so I had to cover all bases. If you took the time to
    Google, for example, twin paradox Doppler, then you would see
    why I had to include it in my list. Here is just one search result for
    you to think about:

    And we agree that there is no clock synchronization, so what's the
    problem with this item?

    However, I do disagree re the relativity of simultaneity item because
    it is simply not a part of the Triplet Case. (Not to mention the fact
    that you have not proved that simultaneity is relative.)

    But if you insist on bringing up the relativity of simultaneity, then
    you need to tell us how this has anything to do with people aging
    differently in different frames. I don't see how it has anything at
    all to do with it.

    I was not talking about the Twin Paradox. I was using the entirely
    different Triplet Paradox. I even gave you a web site. Did you not
    look at it?? And I was not pretending that the RoS doesn't exist,
    but was simply eliminating it as a cause or possible cause for the
    different triplet ages at the end. (Not to remention the fact that you
    have no proof that simultaneity is relative.)

    Are you trying to imply that the Lorentz transformation is the cause of
    the triplets' age difference?

    I want to know why people in different (inertial) frames age differently,
    that's all.
  8. James R Just this guy, you know? Staff Member

    Time dilation.
  9. timewarp Registered Member

    Time dilation is what happened, but I want to know
    the cause.

    What makes people age differently just because they
    are in different (inertial) frames?
  10. James R Just this guy, you know? Staff Member

    Because their clocks run at different rates relative to one another. That's what time dilation means.
  11. OnlyMe Valued Senior Member

    Think of the human body as an elaborate clock. It runs slow in the moving frames of reference, when compared to one at relative rest. The result is the slow clock ages slower and thus less.
  12. Janus58 Valued Senior Member

    No, time dilation is what is measured between frames. This is different than the difference in time that accrues for objects that are separated and brought back together. Time dilation is only one element responsible.
    The fact that the speed c is invariant causes them to measure time and space differently. IOW, what causes the age difference is the combination of time dilation, length contraction and the Relativity of Simultaneity.

    You cannot point to one thing that is responsible for the age difference.

    For example, in the twin paradox, both twins will agree as to who had aged more when they reunite, but they will disagree as to why.

    The Earth twin will say that he aged 10 yrs while his twin only aged 1 yr because his brother's time ran 1/10 as fast as his during the trip (time dilation).

    The space twin will say that he only aged 1 yr because the distance he traveled from Earth before turning around was only 1/10 the distance as measured by him than that as measured by his Earthbound brother (length contraction) He also will say that time went 1/10 as fast for his brother while he was on his outbound and inbound legs of the trip.(due to time dilation, the Earth twin ages only 0.6 month during each leg), But that due to the relativity of simultaneity, his brother aged 9 yrs 10.8 mo, when he made the turn around between legs.

    Two different answers as to why they came to the same end result, and neither answer is better or more valid than the other.
  13. SSDS Banned Banned

    To simplify the twin paradox? – That is very simple. It’s enough to suggest the existance of the absolute spacetime and an absolute reference frame – as that was in pre-Einstein (and more correct) version of "special relativity theory"

    – i.e. in Voigt-FitzGerald-Lorentz theory.

    And the twin paradox disappears...

    More – see, e.g., (I cannot point out full URL) a couple of arXiv links
    and Section2 in

  14. timewarp Registered Member

    You overlooked the fact that there was no E-synch in the triplet example,
    which means that there was no relativity of simultaneity and no observed
    (per two clocks) length contraction.

    In fact, there were no length, time, or any other sort of measurements
    made in the given example.

    There was only an age difference that has no physical explanation so

    Think about this: Three people are born in the same hospital at or about
    the same time. Later, after none of them has accelerated, one is found
    to be an old man, whereas another is still a young man. This is a case of
    an intrinsic (physical, real) age difference. There must be some real or
    physical cause. And whatever this real cause is, it has nothing to do
    with how observers set their clocks or how they view lengths, etc.

    Without anyone observing anything with their clocks and rulers, people
    in different inertial frames age differently, and I wish to know what causes this, please!
  15. Tach Banned Banned

    Mr. Shevchenko, any luck in publishing your crackpot papers or are they doomed to linger for eternity in arxiv?
    It is been quite a few years since you have been pushing them, did any mainstream journal consider them for publication or are you just relegated to pushing them on this forum?
    It is interesting to see that the anti-Einstein, anti-relativity spirit is still alive in the former Soviet Union.
    Last edited: Nov 21, 2011
  16. Janus58 Valued Senior Member

    Yes there are. You have clocks (time measurement). Clock's B and C are some non-zero distance from clock A when they meet, so you have distance. This distance will be shorter for clock's B and C than it will for clock A .No one has to measure this distance, it just is. The time on clock A when they meet will be different for all three clocks, so you have Relativity of Simultaneity. Again, no one has to measure this, it just is.
    I'm afraid that you're in for a disappointment. There is no "physical" cause in the way you mean. It is all about how time and space are measured differently in different inertial frames. It has to do with the way that space and time are interrelated, and how objects with relative motion with respect to each other take different paths through space-time.
  17. OnlyMe Valued Senior Member

    timewarp, the hypothetical you present here will always require clock synchronization. It just synchronizes the clocks at different times and as they pass one onother.

    Further, had you stayed with clocks the hypothetical could eliminate acceleration. As soon as you introduced "triplets" acceleration is required, since triplets had to have begun life in the same frame of reference and then two of them in this hypothetical had to accelerate relative to that initial FoR. In fact the two that require acceleration, prior to this beginning of the hypothetical, must have undergone different accelerations.

    That is the same reason the twins require acceleration, as a component of their hypothetical, they were born relatively, at the same time.
  18. billvon Valued Senior Member

    Don't get too caught up in details of who was born in what hospital. The only thing that matters is what the clocks say after the trip/event/frame shift. The whole twin thing is just a human interest twist on a boring physics gendanken.

    Time. You age a year per year local time. If local time changes (accelerates or decelerates) then you age slower or faster.
  19. SSDS Banned Banned

    - "crackpot papers" - That is a swear-word or a compliment?

    If a compliment - then thanks!

  20. SSDS Banned Banned

    Since there aren't objections from Tach relating to SSDS post above - let think that "crackpot papers" was indeed a compliment.
    So - continue:

    Such a note isn't a first one - there was some other in another forum, and was answered. Because of this discussion is some offtopic, I don't post the answer and point out only corresponding link:

    post SSDS 10 June 2011 - 10:08 AM.

    And - to return to the thread's topic repost some other post from the forum:


    - No. But, as it seems, as well as the SR theory, though:

    Historically some theory that explains the effects appearing at high speeds, i.e. – Michelson–Morley experiment and non-invariance of Maxwell equations at Galilean relativity principle – was created by Voigt, FitzGerald and Lorentz (mainly, there were a number of other contributors) - in 1887 – 1905 (further – "VFL –T"(heory)). In 1905 A. Einstein created some version of the theory that was called "special relativity theory" (SRT). In contrast to the VFL-T, though both were rather similar since were based on the same "Lorentz transformations" (LT), the SRT, as that was declared, is based on two postulates: P1 – relativity principle and P2 – that speed of light is constant in any reference frame. (The postulates weren’t new and implicitly were used at developing of the VFL-T).

    But the declaration above isn’t complete – in reality – and what indeed differs the SRT from the VFL-T – the SRT is based on two additional postulates: P3 – the SRT is a global theory, i.e. the LT are true for special and temporal coordinates x, y,z,t from 0 to +/- infinity, and P4 - there is no absolute reference frame in Universe, all reference frames are absolutely equivalent.

    Just the last two postulates allowed Minkowski to declare:
    …“We should then have in the world no longer space, but an infinite number of spaces, analogously as there are in three-dimensional space an infinite number of planes. Three-dimensional geometry becomes a chapter in four-dimensional physics. Now you know why I said at the outset that space and time are to fade away into shadows, and only a world in itself will subsist".

    From what follows, e.g., that at movement some body/ particle the full space is transformed (4D space time is rotated).

    At that neither P3 nor P4 cannot be proven or experimentally tested – as well as by no ways one can detect "spacetime transformations" and there aren’t any conceivable methods in the SRT – how the spacetime can be affected.

    Besides – given P3 and P4 are true, the SRT became self-contradictory - e.g. – got the twin paradox; from the P4 immediately follows that if there are in spacetime a number of RFs that move with different speeds, then Matter in our Universe has a number of corresponding masses – when it seems evident that there is only unique one, etc.

    The VFL-T is local theory and so hasn’t these contradictions and so is more correct then the SRT. But under unknown reasons just the SRT is used in physics (and in this forum) as standard theory till now...

    Last edited: Nov 24, 2011
  21. SSDS Banned Banned

    And - continue:

    Sorry - what does that mean?

  22. Tach Banned Banned

    this is precisely what I meant in my previous post.

    yep, 100% crackpot
  23. SSDS Banned Banned

    So it seems that "crackpot papers" isn’t a compliment. What’s pity.

    Besides - to the link ( in SSDS post 11-24-11, 05:29 AM an addition appeared in the last couple of weeks. The paper "Space and Time" was rejected by two philosophical journals: "METAPHYSICA" (Germany) and "THEORIA" (Spain). Both – without any concrete remarks (in Metaphysica - after 3 week peer review), though the paper is evidently new, actual, reasonable and philosophical.

    It is interesting – is somewhere a "mainstream" philosophical and/or physical journal where editor board are clever and ethical people?

    But that is some offtopic again.


    To return to the thread’s topic let some brief comment to the OPERA experiment.

    So, from the informational model follows that all/ anything/ everything in Matter move always uninterruptedly in absolute spacetime with the speed of light, c; at that – because of equal footing in any spacetime direction and in the absolute time direction - all/ anything/ everything in Matter is always in the same absolute time’s point.

    If some particle that is born in Matter obtains a spatial speed that differs from the speed of light – including if exceeds c , then it is rather probable that it changes footing in the absolute time also and hence immediately occurs outside Matter and cannot interact with any material particle. As well as any material particles that are produced by such a particle (e.g., electron-positron pairs) will be outside Matter (non-detectable) also.

    So a theory, which considers such a particles, rather probably cannot be verified in an experiment.

    OPERA neutrinos are born at material interactions and are detected in material detector, so it is rather probable that their speed doesn’t exceed c and it is necessary to verify (if the electronics’ delays are estimated correctly) the synchronization (e.g., by transport of a clock from CERN to Italy) and the geodesy…

    Last edited: Dec 1, 2011
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