• [SR] Their proper times will necessarily be equal

    From Richard Hachel@21:1/5 to All on Sat Apr 13 06:36:53 2024
    Let us understand each other (a moment of optimism).

    The immense, the incomparable, the fantastic relativist theorist (that's
    me) wrote:

    "If two different observers travel an identical path in equal observable times,
    then their proper times will necessarily be equal.

    The no less immense, incomparable, and fantastic international Python
    critic refutes.

    And yet, the idea is very simple.

    Let's set up a Galilean frame of reference, in which a Galilean mobile
    moves from left to right on the x axis.

    When it goes to O, in R, we click.

    When it passes x, let's say 12 al, we click.

    For example, we obtain To=12.915.

    Or a speed of Vo=x/To=0.9291c

    Tr=To.sqrt(1-Vo²/c²)=4.776

    Let us pose another body, but this time in uniformly accelerated motion,
    and whose speed will be specially chosen so that To=12.915.

    This means that in R, if they leave together, they arrive together (even
    if they do not have the same speed between them).

    This is where the problem lies with Mr. Python.

    He will immediately assert that the proper times will not be equal, and
    that to write this is to contradict the relativist concept, and,
    inevitably, to be mistaken.

    But let's take a moment at the level of mobiles.

    For the mobile at constant speed, the point to be joined, that is to say which will return to it,
    is at x'=x.sqrt[(1+Vo/c)/(1-Vo/c)] and it moves with a speed of Vapp=Vo/(1-Vo/c).

    For the accelerated mobile, the acceleration is only constant in its
    frame of reference (it is he who accelerates)
    and we have in each part of the path, dTr=dx'/dVapp' or dTr=dTo/sqrt(1-Voi²/c²)

    However, the integration of this, practiced at real speed, leads to Tr=To.sqrt(1+Vrm²/c²).

    That is to say again at Tr=To/sqrt(1-Vo²/c²) where Vo is the same
    speed as in the other Galilean frame of reference.

    We come back once again to:

    "If two different observers travel an identical path in equal observable times,
    then their proper times will necessarily be equal.

    Jean-Pierre Python then asserts that this is absurd, because there is acceleration of one of the mobiles in relation to the other.

    Except that there is also an acceleration of the other in relation to
    the one.

    And when placed on the same equal footing, we cannot differentiate the
    total proper time of one from the total proper time of the other.

    The fact that different observers experience acceleration between them
    is not an admissible objection, because let us take the case of two
    mobiles each performing at the same speed over half a circumference,
    one in hourly revolution, and the other in trigonometric revolution. It is quite obvious that the proper tenses will be equal to each other
    (otherwise it is immediately absurd) during their conjunction.

    And yet, constantly, they will have accelerated and decelerated between
    them, and at every point of their journey.

    It is the same thing with the proper times of two different observers,
    but covering equal portions in equal times.

    Their own times will be equal.

    The relativists' error consists of a poor understanding of the
    calculation of the proper times of objects
    in accelerated movement. They then find a proper time that is too small, compared to the correct proper time.

    They then deduce that the proper times of the two observers described
    above will not be equal.

    Always, always, always the same error is reproduced among them, they
    consider observable speeds as real.

    It's passable in Galilean RR with the artifice of mass change, with the artifice of time skipping, and other useless and ridiculous joys.

    In accelerated benchmarks, continuing with the same falsified principles becomes cumbersome.

    Hence the last criminal proposition of the physicists: "Ah yes, but
    these frames of reference are more like special relativity, they are hyperbolic, geostrategic, Remanian physics,
    and transcendental.

    It's not very serious when you scratch a little.

    It's even a very speech full of abstract religiosity.

    R.H.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Python@21:1/5 to All on Sat Apr 13 13:49:29 2024
    Le 13/04/2024 à 08:36, Richard "Hachel" Lengrand a écrit :
    Let us understand each other (a moment of optimism).

     The immense, the incomparable, the fantastic relativist theorist
    (that's me) wrote:

     "If two different observers travel an identical path in equal
    observable times,
    then their proper times will necessarily be equal.

    [note : I posted a more detailed answer on fr.sci.physique]

    This claim is logically ill-founded to begin with :

    1. From the point of view of any frame of reference the elapsed time
    between ANY pair of events has a UNIQUE value. So "equal observable
    times" is a void proposition.

    2. "Identical path" i.e. "same set of locations" for different
    trajectories is a condition that can be verified in a given
    frame of reference but, then won't be so in other frames.

    A condition that depends on a choice of frame of reference (subjective)
    CANNOT implies a conclusion that does not depend on it ("objective")

    (except in Galilean Relativity, of course, but then all times, proper
    or not are equal, but everything implies an always true proposition,
    and this is not what Lengrand claims)

    So Lengrand's claim is dead in the water at first read.

     Let's set up a Galilean frame of reference, in which a Galilean mobile moves from left to right on the x axis.
    ...
     Let us pose another body, but this time in uniformly accelerated
    motion, and whose speed will be specially chosen so that To=12.915.

     This means that in R, if they leave together, they arrive together
    (even if they do not have the same speed between them).
    ...
     Their own times will be equal.

    This is obviously violating the principle of Relativity. It is obvious
    when you describe the situation in the inertial traveler's frame of
    reference. (except, again, in Galilean Relativiy)

     It's even a very speech full of abstract religiosity.

    If you call religiosity the fact that you are psychologically unable
    to consider anything that went through your mind, without any sensible justification, as wrong, this is, indeed, religiosity. This is more
    correctly called "hubris".

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Python@21:1/5 to All on Sat Apr 13 16:04:47 2024
    Le 13/04/2024 à 16:01, Maciej Wozniak a écrit :
    W dniu 13.04.2024 o 13:49, Python pisze:
    Le 13/04/2024 à 08:36, Richard "Hachel" Lengrand a écrit :
    Let us understand each other (a moment of optimism).

      The immense, the incomparable, the fantastic relativist theorist
    (that's me) wrote:

      "If two different observers travel an identical path in equal
    observable times,
    then their proper times will necessarily be equal.

    [note : I posted a more detailed answer on fr.sci.physique]

    This claim is logically ill-founded to begin with :

    Oh, stinker Python is opening its muzzle again,
    and trying again to pretend he knows something.
    Tell me, poor stinker, have you already  learnt
    what a function is? Are you still trying to
    determine its properties applying a French
    definition of a different word?

    Woz, this thread is not about your own confusions about
    your own confusions.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Maciej Wozniak@21:1/5 to All on Sat Apr 13 16:01:20 2024
    W dniu 13.04.2024 o 13:49, Python pisze:
    Le 13/04/2024 à 08:36, Richard "Hachel" Lengrand a écrit :
    Let us understand each other (a moment of optimism).

      The immense, the incomparable, the fantastic relativist theorist
    (that's me) wrote:

      "If two different observers travel an identical path in equal
    observable times,
    then their proper times will necessarily be equal.

    [note : I posted a more detailed answer on fr.sci.physique]

    This claim is logically ill-founded to begin with :

    Oh, stinker Python is opening its muzzle again,
    and trying again to pretend he knows something.
    Tell me, poor stinker, have you already learnt
    what a function is? Are you still trying to
    determine its properties applying a French
    definition of a different word?

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Maciej Wozniak@21:1/5 to All on Sat Apr 13 17:45:58 2024
    W dniu 13.04.2024 o 16:04, Python pisze:
    Le 13/04/2024 à 16:01, Maciej Wozniak a écrit :
    W dniu 13.04.2024 o 13:49, Python pisze:
    Le 13/04/2024 à 08:36, Richard "Hachel" Lengrand a écrit :
    Let us understand each other (a moment of optimism).

      The immense, the incomparable, the fantastic relativist theorist
    (that's me) wrote:

      "If two different observers travel an identical path in equal
    observable times,
    then their proper times will necessarily be equal.

    [note : I posted a more detailed answer on fr.sci.physique]

    This claim is logically ill-founded to begin with :

    Oh, stinker Python is opening its muzzle again,
    and trying again to pretend he knows something.
    Tell me, poor stinker, have you already  learnt
    what a function is? Are you still trying to
    determine its properties applying a French
    definition of a different word?

    Woz, this thread is not about your own confusions about
    your own confusions.


    Oh, stinker Pyt is opening its muzzle again,
    and trying again to pretend he knows something.
    Tell me, poor stinker, have you already learnt
    what a function is? Are you still trying to
    determine its properties applying a French
    definition of a different word?

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Python@21:1/5 to All on Sat Apr 13 17:46:38 2024
    Le 13/04/2024 à 17:45, Maciej Wozniak a écrit :
    [same bullshit]

    Woz, this thread is not about your own confusions about
    your own confusions.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From gharnagel@21:1/5 to Richard Hachel on Sat Apr 13 16:37:54 2024
    Richard Hachel wrote:

    "If two different observers travel an identical path in equal observable times,

    "Observable"?
    WHO is doing the observing? Presumably, an observer at earth, yes?

    then their proper times will necessarily be equal.

    This is not possible.

    Let's set up a Galilean frame of reference, in which a Galilean mobile moves from left to right on the x axis.

    When it goes to O, in R, we click.

    When it passes x, let's say 12 al, we click.

    For example, we obtain To=12.915.

    Or a speed of Vo=x/To=0.9291c

    Tr=To.sqrt(1-Vo²/c²)=4.776

    This is assuming a constant velocity of v = 0.9291c, yes. The proper time
    of the trip is 4.7746 years, using c = 299792458 m/s and one year equal to 3600*24*365.25 = 31557600 seconds.

    Let us pose another body, but this time in uniformly accelerated motion,

    WHO sees the "uniformly accelerated motion"? The earth observer or the one
    in the ship?

    and whose speed will be specially chosen so that To=12.915.

    Neither the earth observer nor the ship observer sees a "specially chosen" speed. Both will see the ship going faster and faster. An ACCELERATION
    must be specially chosen.

    This means that in R, if they leave together, they arrive together (even
    if they do not have the same speed between them).

    The equations are here (Equ. 6a):

    https://en.wikipedia.org/wiki/Acceleration_(special_relativity)

    I set the problem up using excel. For the ships to arrive together at the
    same time when viewed in the earth frame, the second ship must accelerate
    at 10 m/sec^2. The proper time (ship's time) will take 1.3632 years. The constant-v ship's time is 4.7746 years, so their proper times are NOT equal.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Maciej Wozniak@21:1/5 to All on Sat Apr 13 19:47:00 2024
    W dniu 13.04.2024 o 17:46, Python pisze:
    Le 13/04/2024 à 17:45, Maciej Wozniak a écrit :
    [same bullshit]

    Woz, this thread is not about your own confusions about
    your own confusions.



    Oh, stinker Pyt is opening its muzzle again,
    and trying again to pretend he knows something.
    Tell me, poor stinker, have you already learnt
    what a function is? Are you still trying to
    determine its properties applying a French
    definition of a different word?

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Maciej Wozniak@21:1/5 to All on Sat Apr 13 19:46:24 2024
    W dniu 13.04.2024 o 18:37, gharnagel pisze:
    Richard Hachel wrote:

    "If two different observers travel an identical path in equal
    observable times,

    "Observable"?
    WHO is doing the observing?  Presumably, an observer at earth, yes?

    then their proper times will necessarily be equal.

    This is not possible.

      Let's set up a Galilean frame of reference, in which a Galilean
    mobile moves from left to right on the x axis.

      When it goes to O, in R, we click.

      When it passes x, let's say 12 al, we click.

      For example, we obtain To=12.915.

      Or a speed of Vo=x/To=0.9291c

      Tr=To.sqrt(1-Vo²/c²)=4.776

    This is assuming a constant velocity of v = 0.9291c, yes.  The proper time of the trip is 4.7746 years, using c = 299792458 m/s and one year equal to 3600*24*365.25 = 31557600 seconds.

    AAnd in the meantime in the real world, forbidden
    by your bunch of idiots "improper" clocks keep
    measuring t'=t, just like all serious clocks
    always did.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From gharnagel@21:1/5 to Maciej Wozniak on Sat Apr 13 17:56:06 2024
    Maciej Wozniak wrote:

    AAnd in the meantime in the real world, forbidden
    by your bunch of idiots "improper" clocks keep
    measuring t'=t, just like all serious clocks
    always did.

    The "improper" clocks in orbit keep proper time
    only on earth. In orbit, or on the moon or on Mars,
    they're improper. Wozzie always seems to ignore
    inconvenient truths.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Maciej Wozniak@21:1/5 to All on Sat Apr 13 20:18:17 2024
    W dniu 13.04.2024 o 19:56, gharnagel pisze:
    Maciej Wozniak wrote:

    AAnd in the meantime in the real world, forbidden
    by your bunch of idiots "improper" clocks keep
    measuring t'=t, just like all serious clocks
    always did.

    The "improper" clocks in orbit keep proper time
    only on earth.


    Sure. Why would they do otherwise, Harrie?
    Only brainwashed by The Shit morons like you,
    Harrie, care about its "proper time" absurd.
    Professionals from GPS surely don't.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Python@21:1/5 to All on Sun Apr 14 00:40:06 2024
    Le 13/04/2024 à 19:47, Maciej Wozniak a écrit :
    [same bullshit]

    Woz, this thread is not about your own confusions about
    your own confusions.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Tom Roberts@21:1/5 to Richard Hachel on Sat Apr 20 11:52:36 2024
    On 4/13/24 1:36 AM, Richard Hachel wrote:
    "If two different observers travel an identical path in equal
    observable times, then their proper times will necessarily be equal.

    Yes, of course.

    My response differs from others because I interpret your context
    differently.

    Since you mention "proper times", your context must be relativity; it
    does not matter whether SR or GR, because "travel an identical path"
    means they travel along a single worldline through spacetime -- i.e.
    they are always co-located and co-moving, so of course their elapsed
    proper times are equal (counting from any event on their worldline).

    Your "in equal observable times" is redundant. For any
    observer this directly follows from them following the
    same worldline through spacetime.

    Note this is essentially the first time I agree with Hachel. I doubt
    that he understands why what he wrote is actually correct, because he
    followed it with a bunch of obfuscatory nonsense.

    [... enormous amount of gibberish ignored.]

    Tom Roberts

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Python@21:1/5 to All on Sat Apr 20 19:07:53 2024
    Le 20/04/2024 à 18:52, Tom Roberts a écrit :
    On 4/13/24 1:36 AM, Richard Hachel wrote:
    "If two different observers travel an identical path in equal
    observable times, then their proper times will necessarily be equal.

    Yes, of course.

    My response differs from others because I interpret your context
    differently.

    You interpret path as a path in space-time while Hachel is considering
    path in space only (so it is true in only ONE reference frame)

    For instance, he claims that if two travelers would go from Earth
    to Tau Ceti, one at constant velocity w.r.t Earth the other one
    with a constant acceleration both will measure the same (proper)
    time for their trips.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Maciej Wozniak@21:1/5 to All on Sat Apr 20 22:08:40 2024
    W dniu 20.04.2024 o 18:52, Tom Roberts pisze:
    On 4/13/24 1:36 AM, Richard Hachel wrote:
    "If two different observers travel an identical path in equal
    observable times, then their proper times will necessarily be equal.

    Yes, of course.

    My response differs from others because I interpret your context
    differently.

    Since you mention "proper times", your context must be relativity;


    Sure, only The Shit and its brainwashed followers may be dumb
    enough to believe that sick absurd to have any meaning and
    importance.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From German Dorotea@21:1/5 to Tom Roberts on Sat Apr 20 20:20:40 2024
    Tom Roberts wrote:

    On 4/13/24 1:36 AM, Richard Hachel wrote:
    "If two different observers travel an identical path in equal
    observable times, then their proper times will necessarily be equal.

    Yes, of course. My response differs from others because I interpret your context differently.
    Since you mention "proper times", your context must be relativity; it
    does not matter whether SR or GR, because "travel an identical path"
    means they travel along a single worldline through spacetime -- i.e.
    they are always co-located and co-moving, so of course their elapsed
    proper times are equal (counting from any event on their worldline).
    Your "in equal observable times" is redundant. For any observer this
    directly follows from them following the same worldline through
    spacetime.
    Note this is essentially the first time I agree with Hachel. I doubt
    that he understands why what he wrote is actually correct, because he followed it with a bunch of obfuscatory nonsense.

    i'm not sure. It looks like you think same wordline means same place and trajectory, which is false. A same path through spacetime does not mean
    that.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Richard Hachel@21:1/5 to All on Sat Apr 20 22:31:03 2024
    Le 20/04/2024 à 18:52, Tom Roberts a écrit :
    Yes, of course.

    My response differs from others because I interpret your context
    differently.

    Since you mention "proper times", your context must be relativity; it
    does not matter whether SR or GR, because "travel an identical path"
    means they travel along a single worldline through spacetime -- i.e.
    they are always co-located and co-moving, so of course their elapsed
    proper times are equal (counting from any event on their worldline).

    Your "in equal observable times" is redundant. For any
    observer this directly follows from them following the
    same worldline through spacetime.

    Note this is essentially the first time I agree with Hachel. I doubt
    that he understands why what he wrote is actually correct, because he followed it with a bunch of obfuscatory nonsense.

    [... enormous amount of gibberish ignored.]

    J'ai rien compris.

    R.H.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Athel Cornish-Bowden@21:1/5 to Richard Hachel on Sun Apr 21 10:42:10 2024
    On 2024-04-20 22:31:03 +0000, Richard Hachel said:

    Le 20/04/2024 18:52, Tom Roberts a crit :
    Yes, of course.

    My response differs from others because I interpret your context
    differently.

    Since you mention "proper times", your context must be relativity; it
    does not matter whether SR or GR, because "travel an identical path"
    means they travel along a single worldline through spacetime -- i.e.
    they are always co-located and co-moving, so of course their elapsed
    proper times are equal (counting from any event on their worldline).

    Your "in equal observable times" is redundant. For any
    observer this directly follows from them following the
    same worldline through spacetime.

    Note this is essentially the first time I agree with Hachel. I doubt
    that he understands why what he wrote is actually correct, because he
    followed it with a bunch of obfuscatory nonsense.

    [... enormous amount of gibberish ignored.]

    J'ai rien compris.

    Quelle surprise !

    --
    athel -- biochemist, not a physicist, but detector of crackpots

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Python@21:1/5 to All on Sun Apr 21 16:48:25 2024
    Le 21/04/2024 à 15:53, Ross Finlayson a écrit :
    On 04/20/2024 09:52 AM, Tom Roberts wrote:
    On 4/13/24 1:36 AM, Richard Hachel wrote:
    "If two different observers travel an identical path in equal
    observable times, then their proper times will necessarily be equal.

    Yes, of course.

    My response differs from others because I interpret your context
    differently.

    Since you mention "proper times", your context must be relativity; it
    does not matter whether SR or GR, because "travel an identical path"
    means they travel along a single worldline through spacetime -- i.e.
    they are always co-located and co-moving, so of course their elapsed
    proper times are equal (counting from any event on their worldline).

         Your "in equal observable times" is redundant. For any
         observer this directly follows from them following the
         same worldline through spacetime.

    Note this is essentially the first time I agree with Hachel. I doubt
    that he understands why what he wrote is actually correct, because he
    followed it with a bunch of obfuscatory nonsense.

    [... enormous amount of gibberish ignored.]

    Tom Roberts

    Can you help further explain for the rest of us why
    this isn't necessarily the usual interpretation or
    why it sort of doesn't arrive at the same results of
    some of the usual thought experiments like the traveling twins?

    In the twins scenario, twins does not share the same
    space-time path.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Maciej Wozniak@21:1/5 to All on Sun Apr 21 19:00:10 2024
    W dniu 21.04.2024 o 16:48, Python pisze:
    Le 21/04/2024 à 15:53, Ross Finlayson a écrit :
    On 04/20/2024 09:52 AM, Tom Roberts wrote:
    On 4/13/24 1:36 AM, Richard Hachel wrote:
    "If two different observers travel an identical path in equal
    observable times, then their proper times will necessarily be equal.

    Yes, of course.

    My response differs from others because I interpret your context
    differently.

    Since you mention "proper times", your context must be relativity; it
    does not matter whether SR or GR, because "travel an identical path"
    means they travel along a single worldline through spacetime -- i.e.
    they are always co-located and co-moving, so of course their elapsed
    proper times are equal (counting from any event on their worldline).

         Your "in equal observable times" is redundant. For any
         observer this directly follows from them following the
         same worldline through spacetime.

    Note this is essentially the first time I agree with Hachel. I doubt
    that he understands why what he wrote is actually correct, because he
    followed it with a bunch of obfuscatory nonsense.

    [... enormous amount of gibberish ignored.]

    Tom Roberts

    Can you help further explain for the rest of us why
    this isn't necessarily the usual interpretation or
    why it sort of doesn't arrive at the same results of
    some of the usual thought experiments like the traveling twins?

    In the twins scenario, twins does not share the same
    space-time path.

    Samely like in Star Wars scenario Jedi knighrs wave their
    lightsabers.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Richard Hachel@21:1/5 to All on Sun Apr 21 21:07:31 2024
    Le 21/04/2024 à 16:48, Python a écrit :
    Le 21/04/2024 à 15:53, Ross Finlayson a écrit :
    On 04/20/2024 09:52 AM, Tom Roberts wrote:
    On 4/13/24 1:36 AM, Richard Hachel wrote:
    "If two different observers travel an identical path in equal
    observable times, then their proper times will necessarily be equal.

    Yes, of course.

    My response differs from others because I interpret your context
    differently.

    Since you mention "proper times", your context must be relativity; it
    does not matter whether SR or GR, because "travel an identical path"
    means they travel along a single worldline through spacetime -- i.e.
    they are always co-located and co-moving, so of course their elapsed
    proper times are equal (counting from any event on their worldline).

         Your "in equal observable times" is redundant. For any
         observer this directly follows from them following the
         same worldline through spacetime.

    Note this is essentially the first time I agree with Hachel. I doubt
    that he understands why what he wrote is actually correct, because he
    followed it with a bunch of obfuscatory nonsense.

    [... enormous amount of gibberish ignored.]

    Tom Roberts

    Can you help further explain for the rest of us why
    this isn't necessarily the usual interpretation or
    why it sort of doesn't arrive at the same results of
    some of the usual thought experiments like the traveling twins?

    In the twins scenario, twins does not share the same
    space-time path.

    We may not have the same space-time path, and have the same proper time,
    the same path, and the same improper time (for other observers).
    Note that "space-time path", I don't understand the geometric concept very well.
    Relativist theorists must say clear things if they want to be understood. However, I see that their geometry is not entirely clear and easily understandable. Above all, I see results that are as false as they are
    strange appearing at the end of the race. All this is not normal and
    deserves more serious reflection.

    R.H.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Richard Hachel@21:1/5 to All on Sun Apr 21 21:31:16 2024
    Le 20/04/2024 à 19:07, Python a écrit :
    On 4/13/24 1:36 AM, Richard Hachel wrote:
    "If two different observers travel an identical path in equal
    observable times, then their proper times will necessarily be equal.

    Yes, of course.

    My response differs from others because I interpret your context
    differently.

    You interpret path as a path in space-time while Hachel is considering
    path in space only (so it is true in only ONE reference frame)

    For instance, he claims that if two travelers would go from Earth
    to Tau Ceti, one at constant velocity w.r.t Earth the other one
    with a constant acceleration both will measure the same (proper)
    time for their trips.

    Yes, this is entirely correct.

    If two different protagonists use different frames of reference to join
    Tau Ceti (12al), and if we notice that in the terrestrial frame of
    reference the travel times are similar and the path is similar (direct
    path), then the two proper times will be similar.
    This is the case of a trip by Stella in Galilean mode at constant speed Vo=0.929c, and of a trip in accelerated mode by Bella
    (10m/s²=1.052ly/y²).
    The duration of the trip, which is also very well calculated by my
    relativistic theoretician friends around the world, will be To=x/Vo in the first case, and To=(x/c).sqrt(1+2c²/ax) in the second case, i.e. 12,915
    years.
    But this duration will also be the same for the two rockets with regard to their own time. Tr=4.776 years.
    Physicists tell me that while this is true for Stella, it is not true for Bella.
    However, here, it is they who are mistaken and misuse space-time concepts
    in an accelerated environment.
    On the other hand, be careful, for this to be true, and for it to remain
    true, two clarifications:
    1. You must only use one reference frame during the entire trip.
    2. the accelerated twin must go into “native” state, i.e. at rest.

    R.H.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Python@21:1/5 to All on Sun Apr 21 23:19:00 2024
    Le 21/04/2024 à 23:07, Richard Hachel a écrit :
    Le 21/04/2024 à 16:48, Python a écrit :
    Le 21/04/2024 à 15:53, Ross Finlayson a écrit :
    On 04/20/2024 09:52 AM, Tom Roberts wrote:
    On 4/13/24 1:36 AM, Richard Hachel wrote:
    "If two different observers travel an identical path in equal
    observable times, then their proper times will necessarily be equal.

    Yes, of course.

    My response differs from others because I interpret your context
    differently.

    Since you mention "proper times", your context must be relativity; it
    does not matter whether SR or GR, because "travel an identical path"
    means they travel along a single worldline through spacetime -- i.e.
    they are always co-located and co-moving, so of course their elapsed
    proper times are equal (counting from any event on their worldline).

         Your "in equal observable times" is redundant. For any
         observer this directly follows from them following the
         same worldline through spacetime.

    Note this is essentially the first time I agree with Hachel. I doubt
    that he understands why what he wrote is actually correct, because he
    followed it with a bunch of obfuscatory nonsense.

    [... enormous amount of gibberish ignored.]

    Tom Roberts

    Can you help further explain for the rest of us why
    this isn't necessarily the usual interpretation or
    why it sort of doesn't arrive at the same results of
    some of the usual thought experiments like the traveling twins?

    In the twins scenario, twins does not share the same
    space-time path.

    We may not have the same space-time path, and have the same proper time,
    the same path, and the same improper time (for other observers).

    To have the same improper time is meaningless because in a given
    frame of reference there is a single time elapsed between any
    two events. And there are only two events : travelers' depart
    and travelers' meeting again.

    Moreover to have the same path (in the spatial sense) is a
    property that is only true in a single frame of reference.

    It makes no sense (outside of a trivial one in Galilean Relativity)
    to claim that a condition depending on a given chosen frame could
    imply a property (equality of proper times) that does not depend
    on that.

    Note that "space-time path", I don't understand the geometric concept
    very well.

    It's not a big deal! It is the set of events "traveler is at this
    position at that time".

    [snip babbling]

    Your claim is directly violating the principle of Relativity. End of
    Story.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Python@21:1/5 to All on Sun Apr 21 23:39:56 2024
    Le 21/04/2024 à 23:31, Richard Hachel a écrit :
    Le 20/04/2024 à 19:07, Python a écrit :
    On 4/13/24 1:36 AM, Richard Hachel wrote:
    "If two different observers travel an identical path in equal
    observable times, then their proper times will necessarily be equal.

    Yes, of course.

    My response differs from others because I interpret your context
    differently.

    You interpret path as a path in space-time while Hachel is considering
    path in space only (so it is true in only ONE reference frame)

    For instance, he claims that if two travelers would go from Earth
    to Tau Ceti, one at constant velocity w.r.t Earth the other one
    with a constant acceleration both will measure the same (proper)
    time for their trips.

    Yes, this is entirely correct.

    If two different protagonists use different frames of reference to join
    Tau Ceti (12al), and if we notice that in the terrestrial frame of
    reference the travel times are similar and the path is similar (direct
    path), then the two proper times will be similar.

    The equality of travel times in any frame is always true. There is
    a single value for the time elapsed between two events. You are
    ridiculous, Richard.

    The path being the same is only true in a single inertial frame,
    and false in all others.

    It is logically unsound that a property that depends on a
    chosen frame of reference could imply a property that does
    not. This is basic logic.

    Moreover It is obvious that your claim is violating the principle of Relativity: just consider the situation from the frame of reference of
    the inertial traveler.

    This is quite pathetic that you're unable to grasp such a
    simple argument.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Richard Hachel@21:1/5 to All on Sun Apr 21 21:42:24 2024
    Le 21/04/2024 à 23:19, Python a écrit :
    We may not have the same space-time path, and have the same proper time,
    the same path, and the same improper time (for other observers).

    To have the same improper time is meaningless because in a given
    frame of reference there is a single time elapsed between any
    two events. And there are only two events : travelers' depart
    and travelers' meeting again.

    Moreover to have the same path (in the spatial sense) is a
    property that is only true in a single frame of reference.

    It makes no sense (outside of a trivial one in Galilean Relativity)
    to claim that a condition depending on a given chosen frame could
    imply a property (equality of proper times) that does not depend
    on that.

    Note that "space-time path", I don't understand the geometric concept
    very well.

    It's not a big deal! It is the set of events "traveler is at this
    position at that time".

    [snip babbling]

    Your claim is directly violating the principle of Relativity. End of
    Story.

    Having the same improper time is on the contrary an important relativistic concept, as important as having the same proper time.

    For example, in the example of the two travelers from Tau Ceti, Stella and Bella, one in Galilean mode (Vo=0.929c), the other in accelerated mode (a=1.052ly/y²), we notice that the The observer Terrence (terrestrial)
    will give them the same improper time. That is 12,915 years.

    This means that they leave together, make the same journey, and arrive together, although the journey was never joint at any point of the
    journey.

    This is a point that all physicists in the world accept (I hope).

    It is on Bella's notion of proper time that we no longer agree because the
    way physicists go about it in accelerated frames of reference does not
    seem entirely correct or logical to me.

    R.H.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Richard Hachel@21:1/5 to All on Sun Apr 21 21:44:25 2024
    Le 21/04/2024 à 23:39, Python a écrit :

    The equality of travel times in any frame is always true.

    ? ? ?

    R.H.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Python@21:1/5 to All on Sun Apr 21 23:45:35 2024
    Le 21/04/2024 à 23:42, Richard Hachel a écrit :
    Le 21/04/2024 à 23:19, Python a écrit :
    We may not have the same space-time path, and have the same proper
    time, the same path, and the same improper time (for other observers).

    To have the same improper time is meaningless because in a given
    frame of reference there is a single time elapsed between any
    two events. And there are only two events : travelers' depart
    and travelers' meeting again.

    Moreover to have the same path (in the spatial sense) is a
    property that is only true in a single frame of reference.

    It makes no sense (outside of a trivial one in Galilean Relativity)
    to claim that a condition depending on a given chosen frame could
    imply a property (equality of proper times) that does not depend
    on that.

    Note that "space-time path", I don't understand the geometric concept
    very well.

    It's not a big deal! It is the set of events "traveler is at this
    position at that time".

    [snip babbling]

    Your claim is directly violating the principle of Relativity. End of
    Story.

    Having the same improper time is on the contrary an important
    relativistic concept, as important as having the same proper time.

    Idiot! There are only two events involved! One for when the travelers
    departs and another one when they meet again.

    Hence a SINGLE time elapsed between these two events, as seen in any
    frame of reference.

    Such a triviality about a single value being equal to itself is not
    "important" Richard. It is just showing how silly you are!

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Python@21:1/5 to All on Sun Apr 21 23:47:09 2024
    Le 21/04/2024 à 23:44, Richard Hachel a écrit :
    Le 21/04/2024 à 23:39, Python a écrit :

    The equality of travel times in any frame is always true.

    ? ? ?

    Oh come on!

    There are only two events involved! One for when the travelers
    departs and another one when they meet again.

    Hence a SINGLE time elapsed between these two events, as seen in any
    frame of reference.

    You seemed to have, at least, understood this recently. It appears
    you don't. You are insufferable.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Python@21:1/5 to All on Mon Apr 22 00:03:41 2024
    Le 22/04/2024 à 00:01, Richard Hachel a écrit :
    Le 21/04/2024 à 23:47, Python a écrit :
    Oh come on!

    There are only two events involved! One for when the travelers
    departs and another one when they meet again.

    Hence a SINGLE time elapsed between these two events, as seen in any
    frame of reference.

    You seemed to have, at least, understood this recently. It appears
    you don't. You are insufferable.

    [snip babbing]
    It goes without saying that it defines the time between the joint
    departure event of the two rockets and the joint arrival of the two
    rockets.

    We have entered into tautology there.

    You are the one insisting as taking an always true condition of the
    form a = a as a precondition. This is utterly stupid.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Richard Hachel@21:1/5 to All on Sun Apr 21 21:52:16 2024
    Le 21/04/2024 à 23:42, Python a écrit :
    Le 21/04/2024 à 23:31, Richard Hachel a écrit :
    [snip babbling]
    1. You must only use one reference frame during the entire trip.

    "use" a reference frame... sigh...

    2. the accelerated twin must go into “native” state, i.e. at rest.

    At rest with respect to what? Absolute space again! You are
    insufferable.

    Au repos par rapport au référentiel terrestre qui a permis de mesurer
    une distance de 12 ly, entre la terre et Tau Ceti.

    Je te rappelle que si tu comprends bien la RR du docteur Hachel (c'est
    moi) les notions de longueurs et de distances sont relatives.

    Les 12 ly sont mesurées dans le référentiel terrestre et sont une
    distance propre mesurée par celui-ci.

    Je te rappelle qu'une fusée qui croise la terre à cet instant, et se
    dirige vers Tau Ceti à Vo=0.8c (Vapp=4c) VOIT Tau Ceti à 36 ly.

    Il faut donc que la fusée qui part (Bella) ait un départ au repos pour
    que l'équation soit correcte, et que les temps propres qui sont corrects
    chez moi, soient égaux entre Bella et Stella (4.776 ans).

    R.H.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Richard Hachel@21:1/5 to All on Sun Apr 21 22:01:46 2024
    Le 21/04/2024 à 23:47, Python a écrit :
    Oh come on!

    There are only two events involved! One for when the travelers
    departs and another one when they meet again.

    Hence a SINGLE time elapsed between these two events, as seen in any
    frame of reference.

    You seemed to have, at least, understood this recently. It appears
    you don't. You are insufferable.

    Breathe in, exhale.

    Breathe.

    When Bella and Stella make their trip, they take the same amount of time. Everyone agrees on that.

    The calculated time is the same for all physicists in the world, French, American, German, Spanish, English, and even Richard Hachel.

    Here, 12,915 years old.

    I call this time improper time because it does not correspond to the
    proper time of the two rockets and in any system of relativistic Axelian
    or Minkowskian calculations.

    It goes without saying that it defines the time between the joint
    departure event of the two rockets and the joint arrival of the two
    rockets.

    We have entered into tautology there.

    R.H.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Python@21:1/5 to All on Sun Apr 21 23:42:20 2024
    Le 21/04/2024 à 23:31, Richard Hachel a écrit :
    [snip babbling]
    1. You must only use one reference frame during the entire trip.

    "use" a reference frame... sigh...

    2. the accelerated twin must go into “native” state, i.e. at rest.

    At rest with respect to what? Absolute space again! You are
    insufferable.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)