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causality mess

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altergnostic

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May 22, 2013, 9:58:22 AM5/22/13
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Back in the "experiment that topless einstein" thread I made a question
that i still do not grasp the answer to. It is about the two ships with
equal proper accelerations attached by a wire that breaks due to
relativistic effects.

There are frames in which the front ship fires it's engines before the rear
one, a frame in which they do so simultaneously and frames in which the
rear ship fires before the front one.

Aside from the impression that in the last case the wire would appear to be
compressed, with no justification as to why the wire should snap (which can
be addressed with hyperbolic motion in spacetime), there is a matter of
causality. Here is the question i made back then:

"if the front one launches before the rear one, the distance between ships
is already increasing in this particular frame, right? Just propose a wire
that will break at the slightest change in length. Does it break before or
after the rear ship fires its engines?"

My concern is that the order of events changes and the *cause* of the
breakage does too. In one case it is because the front ship started to
move, in another it is because the rear one did, and in a third case it's
"because" both did simultaneously but the proper accels differ. I don't
agree with the solution, but let's assume it is correct for the sake if
argument. Why isn't the order of events, and the disagreement of the causes
between frames, not a problem? Doesn't it violate causality?

Vertical provided this simple answer:

"causality would not be violated if it broke before the rearward ship
started to accelerate or after the rearward ship started to accelerate. i'm
sure you can see that. consider two boats connected by a string. gun the
engine in the first boat but wait on doing so on the second boat. would you
be surprised if the string broke before the second boat gunned its engine?
would you be surprised if the string broke after the second boat gunned its
engine?"

My answer to that is that i wouldn't be surprised either way, but if i saw
it break before the first boat fired, i would say it broke *because* the
second boat fired it's engines, and since the first ship fires it's engines
after the wire breaks, it's ignition can't be the cause. If the wire broke
before the second boat fired up, the reverse is true.
Now, if someone comes to me later on and says that the wire broke *because*
the first boat fired up, and i saw that it broke *because* the first one
did, we have a disagreement upon the *cause*. Isn't this a violation if
causality? Why wouldn't it be? Or why would it be in non-relativistic
situations but not in relativistic ones? Even considering the hyperbolic
motion in spacetime, this still seems to be a problem.

Anyone?

rotchm

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May 22, 2013, 12:17:42 PM5/22/13
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On May 22, 9:58 am, altergnostic <altergnos...@gmail.com> wrote:
> It is about the two ships with
> equal proper accelerations attached by a wire that breaks due to
> relativistic effects.

First off, your post is too long. You could have reduced it to 25% of
its length.
e.g. the above lines reduces to: "consider the bell spaceship
paradox". Dont overkill.

> There are frames in which the front ship fires it's engines before the rear
> one, a frame in which they do so simultaneously and frames in which the
> rear ship fires before the front one.

ok


> Aside from the impression that in the last case the wire would appear to be
> compressed, with no justification as to why the wire should snap (which can
> be addressed with hyperbolic motion in spacetime), there is a matter of
> causality. Here is the question i made back then:
>
> "if the front one launches before the rear one, the distance between ships
> is already increasing in this particular frame, right?

yes

> Just propose a wire
> that will break at the slightest change in length.

ok

> Does it break before or after the rear ship fires its engines?"

It breaks as the front starts "pulling" and breaks there. The first
millimeter of wire is stretched and breaks as posited by you above.
Since the pulling ship starts first and the pushing ship after and
that the wire breas as the pulling starts, then it breaks before the
pushing ship starts.


> My concern is that the order of events changes and the *cause* of the
> breakage does too.

The word "cause" is not defined here. Define it. The word 'causality'
has several meanings. Which one you want to use?


> In one case it is because the front ship started to
> move, in another it is because the rear one did, and in a third case it's
> "because" both did simultaneously but the proper accels differ.

Dont forget to apply the laws of physics. They say (Maxwell eqs) that
the "material cohesiveness", the "stretchiness" travels at finite
speed (and < c) within the wire: it is stretched, pulled till its
breaking point is attained and ...breaks. You did not consider that
and assumed something contrary to the laws of physics: you assumed
(posited) that the wire is unstreatchable, which is unrealistic. All
materials are stretchable to some extent, no matter how hard they are.
Is it the "magnetic field or the electric field"... remember Einsteins
original thoughts?


There is allot that you are missing in the problem. You have just the
'quick' and popular description of the Bell's paradox.

> I don't agree with the solution, but let's assume it is correct for the sake if
> argument.

It is partially correct. There are blank to fill. These blanks are
obvious to the connoisseur, unknown to the lay, and intrigued by those
in the middle. You seem to be in the middle.

> Why isn't the order of events, and the disagreement of the causes
> between frames, not a problem?

As I said above.


>Doesn't it violate causality?

No, not when you correctly consider all effects. You must describe
the stretching wrt each frame. In each frame you will see that it
stretches to its breaking point and snap there. The popular
description jumps over this since it is not needed: Its stretches, the
final speed of the ships are attained, length contraction should have
contracted the wire, but we assume that the wire is unstreachable, so
it breaks.

enough now.

Lord Androcles, Zeroth Earl of Medway

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May 22, 2013, 12:12:49 PM5/22/13
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"altergnostic" wrote in message news:kniitu$5ic$1...@speranza.aioe.org...
============================================
Your question assumes a result not in evidence.
Do the arithmetic, the wire is relaxed in all cases.
The so-called "length contraction" of Lorentz,
L = LO * sqrt(1-v^2/c^2)
was inverted to length expansion by Einstein in
xi = (x-vt) * 1/sqrt(1-v^2/c^2)

The world is full of sheep that simply cannot read what
he actually wrote and presume they can bleat a louder
"baa" than Einstein's "aab".

-- This message is brought to you from the keyboard of
Lord Androcles, Zeroth Earl of Medway.
When the fools chicken farmer Wilson and Van de faggot present an argument I
cannot laugh at I'll retire from usenet.

Absolutely Vertical

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May 22, 2013, 12:50:35 PM5/22/13
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On 5/22/2013 8:58 AM, altergnostic wrote:

>
> Anyone?
>

a wire is stretched between two movable objects o1 and o2.
1. o1 moves away from o2 and the wire breaks.
2. o2 moves away from o1 and the wire breaks.
3. o1 and o2 both move away from each other and the wire breaks.

would you say that the cause of the wire breaking is different in these
three cases?

Absolutely Vertical

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May 22, 2013, 12:57:59 PM5/22/13
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On 5/22/2013 8:58 AM, altergnostic wrote:

> Anyone?

bringing in another teaching puzzle, a researcher has sitting on a bench
a long rod and a box with two shutters that is shorter than the rod.

now he fires the rod at high speed at the box, which is sitting on the
bench. he has a camera mounted on the box and a camera mounted on the rod.

the observation is that the shutters briefly open and close and the rod
makes contact with nothing as it passes through the box. there is no impact.

the camera on the box records that the shutters close momentarily and at
the same time and then reopen, with the rod inside the box. the cause of
the observation is attributed to the rod being shorter than the box.

the camera on the rod records that the shutters close momentarily but
not at the same time before reopening. the cause of the observation is
attributed to the fact that the first shutter opens before the long rod
gets to it and doesn't close until the back of the rod passes it, and
the second shutter opens a bit later just before the front of the rod
gets to it and then doesn't close until the back of the rod passes it.

has causality been violated by these two different accounts of the events?

Absolutely Vertical

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May 22, 2013, 1:47:20 PM5/22/13
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On 5/22/2013 11:57 AM, Absolutely Vertical wrote:
> On 5/22/2013 8:58 AM, altergnostic wrote:
>
>> Anyone?
>
> bringing in another teaching puzzle, a researcher has sitting on a bench
> a long rod and a box with two shutters that is shorter than the rod.
>
> now he fires the rod at high speed at the box, which is sitting on the
> bench. he has a camera mounted on the box and a camera mounted on the rod.
>
> the observation is that the shutters briefly open and close and the rod
> makes contact with nothing as it passes through the box. there is no
> impact.

sorry typo. ... is that the shutters briefly close and open and the rod
makes ....

Paul Cardinale

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May 22, 2013, 4:06:54 PM5/22/13
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On May 22, 9:12 am, "Lord Androcles, Zeroth Earl of Medway"
<LordAndroc...@May2013.edu> wrote:

> ============================================
> Your question assumes a result not in evidence.
> Do the arithmetic, the wire is relaxed in all cases.
> The so-called "length contraction" of Lorentz,
> L = LO * sqrt(1-v^2/c^2)
> was inverted to length expansion by Einstein in
> xi = (x-vt)  *      1/sqrt(1-v^2/c^2)
>

Here once again androcrap demonstrates that he is utterly incapable of
understanding that the formula for length contraction is something
different than the formula for a coordinate transform. It's not just
that he doesn't understand the formulas, he can't grasp the difference
between the concepts of 'length contraction' and 'coordinate
transformation'.

Lord Androcles, Zeroth Earl of Medway

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May 22, 2013, 5:15:42 PM5/22/13
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"Paul Cardinale" wrote in message
news:9bb93a4f-d96d-4ed7...@s6g2000yqs.googlegroups.com...

On May 22, 9:12 am, "Lord Androcles, Zeroth Earl of Medway"
<LordAndroc...@May2013.edu> wrote:

> ============================================
> Your question assumes a result not in evidence.
> Do the arithmetic, the wire is relaxed in all cases.
> The so-called "length contraction" of Lorentz,
> L = LO * sqrt(1-v^2/c^2)
> was inverted to length expansion by Einstein in
> xi = (x-vt) * 1/sqrt(1-v^2/c^2)
>

Here once again androcrap demonstrates that he is utterly incapable of
understanding that the formula for length contraction is something
different than the formula for a coordinate transform.

==============================================
Here once again the fucking idiot and total MORON Crapinale is
utterly incapable of understanding what a coordinate transformation
is. A ruler of length 0 cm to 30 cm is laid on a grid from 9 cm to 39 cm
doesn't stretch or shrink as it slides past those points at ANY velocity,
you complete and total fucking IMBECILE, dead from the neck up.
The cretin Crapinale has no knowledge of algebra, has never read
Einstein's paper and if he did wouldn't understand it, sneers at others
that can read, and spends his entire life spewing insults at those
with far more intelligence than he. In short, he's just a CUNT.

The world will be a better place, the average happiness and the average
IQ of the human race will rise markedly on the day the Porkie Crapinale
dies.

-- This message is brought to you from the keyboard of

Dirk Van de moortel

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May 22, 2013, 5:26:54 PM5/22/13
to
Lord Androcles, Zeroth Earl of Medway <LordAn...@May2013.edu> wrote:
> "Paul Cardinale" wrote in message
> news:9bb93a4f-d96d-4ed7...@s6g2000yqs.googlegroups.com...
>> On May 22, 9:12 am, "Lord Androcles, Zeroth Earl of Medway"
>> <LordAndroc...@May2013.edu> wrote:
>>> ============================================
>>> Your question assumes a result not in evidence.
>>> Do the arithmetic, the wire is relaxed in all cases.
>>> The so-called "length contraction" of Lorentz,
>>> L = LO * sqrt(1-v^2/c^2)
>>> was inverted to length expansion by Einstein in
>>> xi = (x-vt) * 1/sqrt(1-v^2/c^2)
>>>
>> Here once again androcrap demonstrates that he is utterly incapable of
>> understanding that the formula for length contraction is something
>> different than the formula for a coordinate transform.
>>
> ==============================================
> Here once again the fucking idiot and total MORON Crapinale is
> utterly incapable of understanding what a coordinate transformation
> is.

Androcles understands what a coordinate transformation is:
http://users.telenet.be/vdmoortel/dirk/Physics/Fumbles/InvertingTransformation.html
http://users.telenet.be/vdmoortel/dirk/Physics/Fumbles/AndroTransform.html
http://users.telenet.be/vdmoortel/dirk/Physics/Fumbles/LinearityFight.html
http://users.telenet.be/vdmoortel/dirk/Physics/Fumbles/MisCoTransUnFail.html
http://users.telenet.be/vdmoortel/dirk/Physics/Fumbles/Persuasive.html
http://users.telenet.be/vdmoortel/dirk/Physics/Fumbles/UseTrans.html
http://users.telenet.be/vdmoortel/dirk/Physics/Fumbles/DontEvenKnow.html
http://users.telenet.be/vdmoortel/dirk/Physics/Fumbles/TinyMind.html

> A ruler of length 0 cm to 30 cm is laid on a grid from 9 cm to
> 39 cm doesn't stretch or shrink as it slides past those points at ANY
> velocity, you complete and total fucking IMBECILE, dead from the neck
> up.
> The cretin Crapinale has no knowledge of algebra

Androcles has knowledge of algebra:
http://users.telenet.be/vdmoortel/dirk/Physics/Fumbles/HalfPiDoesNotExist.html
http://users.telenet.be/vdmoortel/dirk/Physics/Fumbles/GOGI-GIGO.html
http://users.telenet.be/vdmoortel/dirk/Physics/Fumbles/Doofus.html
http://users.telenet.be/vdmoortel/dirk/Physics/Fumbles/SetSolve2.html
http://users.telenet.be/vdmoortel/dirk/Physics/Fumbles/AndroDistri.html
http://users.telenet.be/vdmoortel/dirk/Physics/Fumbles/Pythagoras.html
http://users.telenet.be/vdmoortel/dirk/Physics/Fumbles/ToothlessBite.html
http://users.telenet.be/vdmoortel/dirk/Physics/Fumbles/Competent.html
http://users.telenet.be/vdmoortel/dirk/Physics/Fumbles/UseTrans.html
http://users.telenet.be/vdmoortel/dirk/Physics/Fumbles/Sheesh.html
http://users.telenet.be/vdmoortel/dirk/Physics/Fumbles/SetSolve.html
http://users.telenet.be/vdmoortel/dirk/Physics/Fumbles/DivZero.html
http://users.telenet.be/vdmoortel/dirk/Physics/Fumbles/Think.html
http://users.telenet.be/vdmoortel/dirk/Physics/Fumbles/GoodTeachers.html
http://users.telenet.be/vdmoortel/dirk/Physics/Fumbles/TwoTurds.html
http://users.telenet.be/vdmoortel/dirk/Physics/Fumbles/STILL.html
http://users.telenet.be/vdmoortel/dirk/Physics/Fumbles/CanSpecify.html
http://users.telenet.be/vdmoortel/dirk/Physics/Fumbles/Nearly.html
http://users.telenet.be/vdmoortel/dirk/Physics/Fumbles/Quadratic.html
http://users.telenet.be/vdmoortel/dirk/Physics/Fumbles/GrowUp.html
http://users.telenet.be/vdmoortel/dirk/Physics/Fumbles/Tautology.html
http://users.telenet.be/vdmoortel/dirk/Physics/Fumbles/Material.html
http://users.telenet.be/vdmoortel/dirk/Physics/Fumbles/GIVEN.html
http://users.telenet.be/vdmoortel/dirk/Physics/Fumbles/PythagoRescue.html
http://users.telenet.be/vdmoortel/dirk/Physics/Fumbles/SqrtRev.html
http://users.telenet.be/vdmoortel/dirk/Physics/Fumbles/NegSqrt.html
http://users.telenet.be/vdmoortel/dirk/Physics/Fumbles/Humour.html
http://users.telenet.be/vdmoortel/dirk/Physics/Fumbles/SqrtAnswers.html

Dirk Vdm

Lord Androcles, Zeroth Earl of Medway

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May 22, 2013, 6:52:44 PM5/22/13
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"Dirk Van de moortel" wrote in message
news:knjd6p$uub$1...@speranza.aioe.org...
================================================
Thank you, Dork, for carefully selecting my gems and showing your fumbles.
Making lists seems to be your forte.

A ruler of length 0 cm to 30 cm is laid on a grid from 9 cm to
39 cm doesn't stretch or shrink as it slides past those points at ANY
velocity, you complete and total fucking IMBECILE, dead from the neck
up. (This time addressed to Dork Van der faggot.)

-- This message is brought to you from the keyboard of

altergnostic

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May 22, 2013, 7:31:49 PM5/22/13
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rotchm <rot...@gmail.com> wrote:
> On May 22, 9:58 am, altergnostic <altergnos...@gmail.com> wrote:
>> It is about the two ships with
>> equal proper accelerations attached by a wire that breaks due to
>> relativistic effects.
>
> First off, your post is too long. You could have reduced it to 25% of
> its length.
> e.g. the above lines reduces to: "consider the bell spaceship
> paradox". Dont overkill.

You lazy person... I have a hard time with synthesis, sorry.

>
>> There are frames in which the front ship fires it's engines before the rear
>> one, a frame in which they do so simultaneously and frames in which the
>> rear ship fires before the front one.
>
> ok
>
>
>> Aside from the impression that in the last case the wire would appear to be
>> compressed, with no justification as to why the wire should snap (which can
>> be addressed with hyperbolic motion in spacetime), there is a matter of
>> causality. Here is the question i made back then:
>>
>> "if the front one launches before the rear one, the distance between ships
>> is already increasing in this particular frame, right?
>
> yes
>
>> Just propose a wire
>> that will break at the slightest change in length.
>
> ok
>
>> Does it break before or after the rear ship fires its engines?"
>
> It breaks as the front starts "pulling" and breaks there. The first
> millimeter of wire is stretched and breaks as posited by you above.
> Since the pulling ship starts first and the pushing ship after and
> that the wire breas as the pulling starts, then it breaks before the
> pushing ship starts.
>
>
>> My concern is that the order of events changes and the *cause* of the
>> breakage does too.
>
> The word "cause" is not defined here. Define it. The word 'causality'
> has several meanings. Which one you want to use?

I refer to cause and effect, the order of events, one event being the
physical cause of the next.

>
>
>> In one case it is because the front ship started to
>> move, in another it is because the rear one did, and in a third case it's
>> "because" both did simultaneously but the proper accels differ.
>
> Dont forget to apply the laws of physics. They say (Maxwell eqs) that
> the "material cohesiveness", the "stretchiness" travels at finite
> speed (and < c) within the wire: it is stretched, pulled till its
> breaking point is attained and ...breaks. You did not consider that
> and assumed something contrary to the laws of physics: you assumed
> (posited) that the wire is unstreatchable, which is unrealistic. All
> materials are stretchable to some extent, no matter how hard they are.
> Is it the "magnetic field or the electric field"... remember Einsteins
> original thoughts?

It doesn't matter. Suppose the fastest possible breakage if the wire, due
to the minimal possible change. Or doesn't! What matters is the order of
events.

altergnostic

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May 22, 2013, 7:32:51 PM5/22/13
to
"Lord Androcles, Zeroth Earl of Medway" <LordAn...@May2013.edu> wrote:
===========================================Your question assumes a result
not in evidence.
> Do the arithmetic, the wire is relaxed in all cases.
> The so-called "length contraction" of Lorentz,
> L = LO * sqrt(1-v^2/c^2)
> was inverted to length expansion by Einstein in
> xi = (x-vt) * 1/sqrt(1-v^2/c^2)
>
> The world is full of sheep that simply cannot read what
> he actually wrote and presume they can bleat a louder
> "baa" than Einstein's "aab".
>
> -- This message is brought to you from the keyboard of
> Lord Androcles, Zeroth Earl of Medway.
> When the fools chicken farmer Wilson and Van de faggot present an argument I
> cannot laugh at I'll retire from usenet.

Yes, assuming the accepted explanation is true. Regardless if it is or
isn't, i still find it internally inconsistent, unless causality is no
longer considered a fact. Or i still miss the complete meaning of this
solution, and i want to have a clear understanding of what is the accepted
solution.

altergnostic

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May 22, 2013, 7:41:52 PM5/22/13
to
No. But that depends, what is the cause of the motion?
I realize we have a three-step cause and effect situation. From end to
start:
C. Wire breaks
B. Due to the movement of the ships
A. Due to the accel from the engine

If you stop at 2, there seems to be no problem, so, in your 123 scenarios,
all of them could be caused by the firing of either engines. o1 fires up
and causes 1 2 and 3. Conversely, o2 fires and causes 1 2 and 3. See what i
mean?

altergnostic

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May 22, 2013, 7:48:29 PM5/22/13
to
Classic.
No problem here, these effects of SR are not considered changes in physical
processes, so the differences are frame dependent.
A wire breaking is a physical process, strictly mechanical, which requires
mechanical causes that are changes in physical processes themselves
(ignition).
Totally different situation.

Lord Androcles, Zeroth Earl of Medway

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May 22, 2013, 8:16:08 PM5/22/13
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"altergnostic" wrote in message news:knjkj3$jft$1...@speranza.aioe.org...
================================================
Accepted explanation?
There can be no "acceptance" in mathematics, there is only proof.
Mathematics is NOT a democracy where majority opinion decides.

The moron Einstein wrote:
"Thus, whereas the Y and Z dimensions of the sphere (and therefore of every
rigid body of no matter what form) do not appear modified by the motion, the
X dimension appears shortened in the ratio 1: sqrt(1-v^2/c^2) , i.e. the
greater the value of v, the greater the shortening. For v=c all moving
objects—viewed from the “stationary” system—shrivel up into plane figures."

That is in DIRECT CONTRADICTION to xi = (x-vt) / sqrt(1-v^2/c^2)
which the clown derived himself.
It really is that fucking simple!

xi is GREATER than (x-vt) BECAUSE sqrt(1-v^2/c^2) is LESS THAN 1.
2 is GREATER than 1 because 0.5 is LESS THAN 1 and 2 = 1/0.5
It really is that fucking simple!

10,000,000 arseholes can mumble "Lorentz contraction", it still won't
be Einstein's expansion and that bozo had no idea what we was doing.
It really is that fucking simple!

Lord Androcles, Zeroth Earl of Medway

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May 22, 2013, 8:18:00 PM5/22/13
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"altergnostic" wrote in message news:knjkh4$jd1$1...@speranza.aioe.org...
==============================================
No algebra, only bullshit.

Lord Androcles, Zeroth Earl of Medway

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May 22, 2013, 8:18:20 PM5/22/13
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"altergnostic" wrote in message news:knjl3v$kmf$1...@speranza.aioe.org...

Lord Androcles, Zeroth Earl of Medway

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May 22, 2013, 8:18:31 PM5/22/13
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"altergnostic" wrote in message news:knjlga$lf0$1...@speranza.aioe.org...

rotchm

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May 22, 2013, 8:40:35 PM5/22/13
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On May 22, 7:31 pm, altergnostic <altergnos...@gmail.com> wrote:
> rotchm <rot...@gmail.com> wrote:
elativistic effects.
>
> > First off, your post is too long. You could have reduced it to 25% of
> > its length.

> You lazy person... I have a hard time with synthesis, sorry.

That makes you the lazy one; you do not put enough time and effort to
produce a quick/simple/concise text. Prhaps you do have hard time
with synthesis, but dont bestow that onto us. Take your time, take a
week, a month if need be, to better your "test"... Lazy you....

> > The word "cause" is not defined here. Define it. The word 'causality'
> > has several meanings. Which one you want to use?
>
> I refer to cause and effect, the order of events, one event being the
> physical cause of the next.

"Physical cause" is an old and defunct concept in (higher) physics. It
is part of philosophy.
If I punch you (lightly) on the nose and you start bleeding, is my
punch the cause? Is it your weak nose the cause or your high blood
pressure the cause or your slow reflexes the cause or your weak
capillaries or your attempt to rob me? Everything conspires to the
"cause". The creation of the universe is the "cause", since w/o it,
you would not have been punched! So, this type of caus(ality) is
devoid of physical interest.

Order of events. Two events are said to be causal if they are timelike
(some include lightlike). IOW if light can reach both before one event
"signals" the other. The order of events has nothing to do with this
definition of "causal" and will not change the predictions of SR (or
any other good model).

Think of the bug-rivet paradox where the order of events is switched.
In one the bug dies first whereas in the other frame it dies after.

> It doesn't matter. Suppose the fastest possible breakage if the wire, due
> to the minimal possible change.

Ok, just as you pull it, it breaks there, "1 millimiter " from the
stretching.
In all frames it will be stretched from the front so it will break
there.

> Or doesn't! What matters is the order of events.

If its sufficiently stretchable, it wont break. No, the order of
events dont matter here.

altergnostic

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May 22, 2013, 11:59:30 PM5/22/13
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rotchm <rot...@gmail.com> wrote:
> On May 22, 7:31 pm, altergnostic <altergnos...@gmail.com> wrote:
>> rotchm <rot...@gmail.com> wrote:
> elativistic effects.
>>
>>> First off, your post is too long. You could have reduced it to 25% of
>>> its length.
>
>> You lazy person... I have a hard time with synthesis, sorry.
>
> That makes you the lazy one; you do not put enough time and effort to
> produce a quick/simple/concise text. Prhaps you do have hard time
> with synthesis, but dont bestow that onto us. Take your time, take a
> week, a month if need be, to better your "test"... Lazy you....

I guess you are right... I really am eager to post sometimes.

>
>>> The word "cause" is not defined here. Define it. The word 'causality'
>>> has several meanings. Which one you want to use?
>>
>> I refer to cause and effect, the order of events, one event being the
>> physical cause of the next.
>
> "Physical cause" is an old and defunct concept in (higher) physics. It
> is part of philosophy.
> If I punch you (lightly) on the nose and you start bleeding, is my
> punch the cause? Is it your weak nose the cause or your high blood
> pressure the cause or your slow reflexes the cause or your weak
> capillaries or your attempt to rob me? Everything conspires to the
> "cause". The creation of the universe is the "cause", since w/o it,
> you would not have been punched! So, this type of caus(ality) is
> devoid of physical interest.

Whoa, hold your horses!
I'm talking about a *change in physical processes* that *generates* a
following *change in physical processes*.
If it stretches *because* the distance grows *because* one ship fired up,
not *because* the other did, the reverse can't also be true at the same
time! That would require parallel realities!

>
> Order of events. Two events are said to be causal if they are timelike
> (some include lightlike). IOW if light can reach both before one event
> "signals" the other. The order of events has nothing to do with this
> definition of "causal" and will not change the predictions of SR (or
> any other good model).
>
> Think of the bug-rivet paradox where the order of events is switched.
> In one the bug dies first whereas in the other frame it dies after.

Yes, in this situation the order of events doesn't matter. Remember, my
problem is not that the order of events differ from frame to frame, this is
really easy to prove even without SR, all we need is the finite speed of
light.
My problem is when one event is related to another causally in one frame
and not in the other, where the same event has a completely different
cause. That is what i still can't cope with.

>
>> It doesn't matter. Suppose the fastest possible breakage if the wire, due
>> to the minimal possible change.
>
> Ok, just as you pull it, it breaks there, "1 millimiter " from the
> stretching.
> In all frames it will be stretched from the front so it will break
> there.
>
>> Or doesn't! What matters is the order of events.
>
> If its sufficiently stretchable, it wont break. No, the order of
> events dont matter here.

Well, my concern is related to which event is causally related to the wire
breaking. Is it ship1 ignition? Is it ship2's? Both? Neither? Wtf?

rotchm

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May 23, 2013, 12:27:54 AM5/23/13
to
On May 22, 11:59 pm, altergnostic <altergnos...@gmail.com> wrote:
> rotchm <rot...@gmail.com> wrote:


> If it stretches *because* the distance grows *because* one ship fired up,
> not *because* the other did, the reverse can't also be true at the same
> time! That would require parallel realities!

? No idea what you are talking about. It doesnt stretch because you
posited that it does not. So either you pull it and it immediately
breaks, or it stretches.

OTOH, Laws of physics say that nothing is rigid, therefore you cannot
posit that its rigid when analyzing a physical process.

> My problem is when one event is related to another causally in one frame
> and not in the other, where the same event has a completely different
> cause. That is what i still can't cope with.

Your inability to cope with it will not change the math, nor the
predictions nor the agreement to exp's.


> Well, my concern is related to which event is causally related to the wire
> breaking. Is it ship1 ignition? Is it ship2's? Both? Neither? Wtf?

There are many contributions to the breaking. The initial pull, the
elasticity (internal EM or cohesiveness) , the "pulling wave".

For instance, if the ship pulls too fast, the wire will immediately
break. If he pulls slow, it will not break yet or even perhaps not at
all, depending on its elasticity.

John Gogo

unread,
May 23, 2013, 12:51:47 AM5/23/13
to
You still think that the universal constant c, still rules. Only in
special circumstance.

altergnostic

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May 23, 2013, 9:14:16 AM5/23/13
to
Rotchie, please. If you don't want to think about it abd address what
troubles me, fine.
As i said many times, i am NOT arguing math, predictions or models. Nor how
the wire breaks, or how fast. I am looking at the ORDER IF EVENTS and which
IGNITION event can be taken as a cause (in the line of causes) of the
breakage. I simply don't get how two DIFFERENT events can be taken as the
cause in different frames, with the other ship's ignition NOT be taken as a
cause in either frame. It seems to be a rather serious disagreement. Why
isn't it?

Absolutely Vertical

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May 23, 2013, 9:33:10 AM5/23/13
to
On 5/22/2013 6:31 PM, altergnostic wrote:
> I refer to cause and effect, the order of events, one event being the
> physical cause of the next.

and here is the problem. spacelike-separated events do not have
frame-independent order, and so cannot be pair in a cause-effect
relationship in this sense.

so you have to be pretty careful about identifying which is the cause
and which is the effect in the analysis of this situation.

Absolutely Vertical

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May 23, 2013, 9:39:49 AM5/23/13
to
of course i do. the question is whether the wire cares and whether the
frame-dependence of the accounting amounts to what you referred to as
'violation of causality'.

consider the case where neither o1 or o2 are accelerating. they are just
coasting, and a wire happens to be caught by both of the ships as they
pass. then there is no A.

Absolutely Vertical

unread,
May 23, 2013, 9:41:45 AM5/23/13
to
On 5/22/2013 6:48 PM, altergnostic wrote:

>
> Classic.
> No problem here, these effects of SR are not considered changes in physical
> processes, so the differences are frame dependent.
> A wire breaking is a physical process, strictly mechanical, which requires
> mechanical causes that are changes in physical processes themselves
> (ignition).
> Totally different situation.
>

good. now consider the case where the shutters stay closed....

altergnostic

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May 23, 2013, 9:49:40 AM5/23/13
to
"Lord Androcles, Zeroth Earl of Medway" <LordAn...@May2013.edu> wrote:
> "altergnostic" wrote in message news:knjkj3$jft$1...@speranza.aioe.org...
>
> "Lord Androcles, Zeroth Earl of Medway" <LordAn...@May2013.edu> wrote:
> ===========================================Your question assumes a result
> not in evidence.
>> Do the arithmetic, the wire is relaxed in all cases.
>> The so-called "length contraction" of Lorentz,
>> L = LO * sqrt(1-v^2/c^2)
>> was inverted to length expansion by Einstein in
>> xi = (x-vt) * 1/sqrt(1-v^2/c^2)
>>
>> The world is full of sheep that simply cannot read what
>> he actually wrote and presume they can bleat a louder
>> "baa" than Einstein's "aab".
>>
>> -- This message is brought to you from the keyboard of
>> Lord Androcles, Zeroth Earl of Medway.
>> When the fools chicken farmer Wilson and Van de faggot present an argument
>> I
>> cannot laugh at I'll retire from usenet.
>
> Yes, assuming the accepted explanation is true. Regardless if it is or
> isn't, i still find it internally inconsistent, unless causality is no
> longer considered a fact. Or i still miss the complete meaning of this
> solution, and i want to have a clear understanding of what is the accepted
> solution.
> ===============================================Accepted explanation?
> There can be no "acceptance" in mathematics, there is only proof.
> Mathematics is NOT a democracy where majority opinion decides.

Two things:
1. Agreed, but just assume it for the sake of argument. IF the solution is
taken as correct, it still yields the problem i raised, and i want to know
how it is addressed by those who accept it.
2. Don't pretend science or any other human endeavor is not affected by
democracy or influence from authority.

altergnostic

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May 23, 2013, 9:51:45 AM5/23/13
to
And there is no acceleration either, and no bell's paradox. What's your
point?

altergnostic

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May 23, 2013, 9:52:46 AM5/23/13
to
What about it?

Absolutely Vertical

unread,
May 23, 2013, 10:56:51 AM5/23/13
to
it's a different case, designed to probe your ideas about causality.

Absolutely Vertical

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May 23, 2013, 10:57:26 AM5/23/13
to
account for what happens, as seen in the two cameras.

Lord Androcles, Zeroth Earl of Medway

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May 23, 2013, 11:02:21 AM5/23/13
to
"altergnostic" wrote in message news:knl6ph$iu7$1...@speranza.aioe.org...
=========================================
IF Santa Claus delivers toys by coming down chimneys is taken as
correct, it still yields the problem of soot getting on his red suit and
I want to know how it is cleaned every visit by those that accept it.
(Actually I don't. I couldn't give a flying fuck what some idiot's
explanation of the fairy tale is and I'm wondering if you are sane
for wanting to know the explanation of non-existent problems which
any fool can create.)


2. Don't pretend science or any other human endeavor is not affected by
democracy or influence from authority.
==========================================
Human endeavour can be affected by many influences, but science
is the observation, investigation and explanation of natural
phenomena or occurrences and if the explanation is wrong
then it isn't science. Where light and relativity are concerned
it is the observation that is wrong. Nobody has ever observed
light always propagated in empty space with a definite velocity
c which is independent of the state of motion of the emitting
body, that's a fairy tale and so is anything derived from it.
I don't pretend fairy tales are science. If you want to call relativity
"science" then so is Santa Claus.

rotchm

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May 23, 2013, 11:27:04 AM5/23/13
to
On May 23, 9:14 am, altergnostic <altergnos...@gmail.com> wrote:


> As i said many times, i am NOT arguing math, predictions or models. Nor how
> the wire breaks, or how fast. I am looking at the ORDER IF EVENTS and which
> IGNITION event can be taken as a cause (in the line of causes) of the
> breakage. I simply don't get how two DIFFERENT events can be taken as the
> cause in different frames, with the other ship's ignition NOT be taken as a
> cause in either frame.

There is a cascade of events in your example. Be specific: what events
you thing "ignite" the breakage? Then which ones no longer "ignite"
the breakage in the other frame?

Or, can you imagine a simpler/clearer example instead of Bell's?

altergnostic

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May 23, 2013, 12:54:42 PM5/23/13
to
Let me put it this way. If some observable is not a change physical
process, the order of events does not violate causality, since the observed
feature is not the cause of a physical change, or part of the line of
causes. In inertial frames, this problem never arises, since there are no
changes in physical processes (i'm talking about relativistic effects here,
of course: two bodies moving apart would cause the breaking by strictly
mechanical processes, regardless of relativity). So, two bodies moving at
tge same speed in the x axis would not cause any breakage, and moving at
different speeds would, and the cause would only be the increase in spatial
separation. I see no problem here.

But when there is a change from a inertial state of motion, it has to be
accounted for by some real cause, and since it generates a real change in
the structure of the wire, the firing of the engine that occurs after the
wire breaks can hardly be the cause, and if two frames disagree about the
cause - which ignition caused the L increase that caused the breakage - i
see a problem. I'm wondering why you think it isn't.

altergnostic

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May 23, 2013, 1:13:06 PM5/23/13
to
?
If the shutters don't open the rod bumps into the box! Wtf?
I'm sure i'm missing your point here, could you be more specific?
In any case, my previous post should clarify what i mean by causal related
events.

rotchm

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May 23, 2013, 1:21:17 PM5/23/13
to
On May 23, 12:54 pm, altergnostic <altergnos...@gmail.com> wrote:

> two bodies moving apart would cause the breaking by strictly
> mechanical processes, regardless of relativity).

Yes, but them moving apart is not the only cause. many causes
contribute to the breaking.

> So, two bodies moving at tge same speed in the x axis would not cause any breakage,

Yes they can, depending on the elasticity. This is true even in
classical kinematics/EM.

> and moving at different speeds would,

Would moreso.

> and the cause would only be the increase in spatial
> separation. I see no problem here.

And elasticity etc...

> But when there is a change from a inertial state of motion, it has to be
> accounted for by some real cause, and since it generates a real change in
> the structure of the wire, the firing of the engine that occurs after the
> wire breaks can hardly be the cause, and if two frames disagree about the
> cause - which ignition caused the L increase that caused the breakage - i
> see a problem. I'm wondering why you think it isn't.

Ah... I see what u mean now. The wire breaks because it is stretched.
In every frame it is stretched. In every frame it is being pulled
first as you can conclude by applying the LT.

Absolutely Vertical

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May 23, 2013, 2:14:16 PM5/23/13
to
sure, let me be direct. the rod will only hit _one_ of the shutters, the
one at the back of the back of the box, and the front of the pole will
hit it from the inside of the box.

but the other shutter will not close on the pole. there will be no mark
on either the pole or the shutter from a collision between the two.

the question now is how to account for _why_. (the cause, if you like.)
do this from the frame of the box, and then do it from the frame of the
pole.

altergnostic

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May 23, 2013, 7:39:09 PM5/23/13
to
But how can it be pulled first in the frame in which the rear ship fires up
before the frontmost one?

altergnostic

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May 23, 2013, 7:52:44 PM5/23/13
to
Let's assume the rod hits the shutter and passes right through it. In the
frame of the box, the rod fits inside the box, so when both shutters close,
the rod is completely inside, as it continues to move forward, it hits the
front shutter. The shutter on the back never touched the rid.
In the frame of the rod, it passes through the first shutter, which closes
after the back end of the rod has already passed through. The front end
hits the second shutter before the first shutter closes.
I don't see any disagreement in the line of causes. Consider a setup in
which the rod breaks if it hits a shutter. All frames agree that it does so
because it hits the front one, not the back one.

xxein

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May 23, 2013, 9:49:46 PM5/23/13
to
On May 22, 9:58 am, altergnostic <altergnos...@gmail.com> wrote:
> Back in the "experiment that topless einstein" thread I made a question
> that i still do not grasp the answer to. It is about the two ships with
> equal proper accelerations attached by a wire that breaks due to
> relativistic effects.
>
> There are frames in which the front ship fires it's engines before the rear
> one, a frame in which they do so simultaneously and frames in which the
> rear ship fires before the front one.
>
> Aside from the impression that in the last case the wire would appear to be
> compressed, with no justification as to why the wire should snap (which can
> be addressed with hyperbolic motion in spacetime), there is a matter of
> causality. Here is the question i made back then:
>
> "if the front one launches before the rear one, the distance between ships
> is already increasing in this particular frame, right? Just propose a wire
> that will break at the slightest change in length. Does it break before or
> after the rear ship fires its engines?"
>
> My concern is that the order of events changes and the *cause* of the
> breakage does too. In one case it is because the front ship started to
> move, in another it is because the rear one did, and in a third case it's
> "because" both did simultaneously but the proper accels differ. I don't
> agree with the solution, but let's assume it is correct for the sake if
> argument. Why isn't the order of events, and the disagreement of the causes
> between frames, not a problem? Doesn't it violate causality?
>
> Vertical provided this simple answer:
>
> "causality would not be violated if it broke before the rearward ship
> started to accelerate or after the rearward ship started to accelerate. i'm
> sure you can see that. consider two boats connected by a string. gun the
> engine in the first boat but wait on doing so on the second boat. would you
> be surprised if the string broke before the second boat gunned its engine?
> would you be surprised if the string broke after the second boat gunned its
> engine?"
>
> My answer to that is that i wouldn't be surprised either way, but if i saw
> it break before the first boat fired, i would say it broke *because* the
> second boat fired it's engines, and since the first ship fires it's engines
> after the wire breaks, it's ignition can't be the cause. If the wire broke
> before the second boat fired up, the reverse is true.
> Now, if someone comes to me later on and says that the wire broke *because*
> the first boat fired up, and i saw that it broke *because* the first one
> did, we have a disagreement upon the *cause*. Isn't this a violation if
> causality? Why wouldn't it be? Or why would it be in non-relativistic
> situations but not in relativistic ones? Even considering the hyperbolic
> motion in spacetime, this still seems to be a problem.
>
> Anyone?

xxein: It's only your problem of not understanding what's really
going on.

Paul Cardinale

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May 23, 2013, 11:24:54 PM5/23/13
to
On May 22, 2:15 pm, "Lord Androcles, Zeroth Earl of Medway"
<LordAndroc...@May2013.edu> wrote:
> "Paul Cardinale"  wrote in message
>
> news:9bb93a4f-d96d-4ed7...@s6g2000yqs.googlegroups.com...
>
> On May 22, 9:12 am, "Lord Androcles, Zeroth Earl of Medway"
>
> <LordAndroc...@May2013.edu> wrote:
> ==============================================
> Here once again the fucking idiot and total MORON Crapinale is
> utterly incapable of understanding what a coordinate transformation
> is.  A ruler of length 0 cm to 30 cm ...

AND YET AGAIN! "A ruler of length 0 cm to 30 cm ..." is perfect
demonstration that he just can't grasp the difference between
coordinates and distance!

rotchm

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May 23, 2013, 11:42:43 PM5/23/13
to
On May 23, 7:39 pm, altergnostic <altergnos...@gmail.com> wrote:
> But how can it be pulled first in the frame in which the rear ship fires up
> before the frontmost one?

Doesnt matter when you think of it. It is pulled in all frames. This
pulling will break the wire, no matter when the pulling is done.
Dont forget, in the trivial frame, the front pulls and the rear
pushes. A "pulling wave" travels through the wire and so does a
pushing wave. In the frame where the push is first, a pushing wave
travels through the wire and a little later the pulling ships starts
pulling. The wire will break when its internal "stretchiness" is
attained. The "cause" is still the "pull".

Lord Androcles, Zeroth Earl of Medway

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May 24, 2013, 1:44:40 AM5/24/13
to
"Paul Cardinale" wrote in message
news:86af2d23-0e96-4fb3...@k4g2000yqb.googlegroups.com...
====================================================
Okay, you stupid fuck, why don't you tell is all what the x, y ands z
coordinates of a school ruler are and the what the "difference" is?




altergnostic

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May 24, 2013, 9:37:56 AM5/24/13
to
If that was really the case, i'd see no problem. But the way i understand
it, there is a frame in which the sequence of events is as follows:
1- the rear ship fires up
2- the wire breaks
3- the front ship fires up

In such frame, the "pull" does not cause the breakage.
Furthermore, your description sounds unrelativistic. It isn't really a pull
because the front ship pulls it more than the rear ship pushes: that would
work only as a description in space, but not exactly in spacetime.

rotchm

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May 24, 2013, 10:23:02 AM5/24/13
to
On May 24, 9:37 am, altergnostic <altergnos...@gmail.com> wrote:

> If that was really the case, i'd see no problem.

Ok then.

> But the way i understand
> it, there is a frame in which the sequence of events is as follows:
> 1- the rear ship fires up
> 2- the wire breaks
> 3- the front ship fires up
> In such frame, the "pull" does not cause the breakage.

No that doesnt happen in any frame. The sequence in all frames is (1<--
>3),2.
2 is always last, in every frame. in the frame where both ships start
simul, those two events are not causal. But The pulling ship and
breakage are causal (delta_t > 0) and in every other frame, the LT's
show that delta_t' > 0 also. The "pulling pressure wave" is slower
that the SoL in every frame.

> Furthermore, your description sounds unrelativistic. It isn't really a pull
> because the front ship pulls it more than the rear ship pushes: that would
> work only as a description in space, but not exactly in spacetime.

As I (and many here in the past) said, the full description is quite
complicated. You need to describe (relativisticlly) the EM between the
constituents (altoms...) of the wire (globally, this is what I was
calling the "pushing" or "pressure wave" etc). See Born rigid motion.

altergnostic

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May 24, 2013, 2:04:59 PM5/24/13
to
I did consider born rigid motion before.
So you are saying the solution is related to the time it takes for the pull
to travel through the wire until it breaks and that the added times of this
traveling through the wire plus the time light takes to reach the observer
from the breakage point will always be less than the time it takes light
from the second ship's exhaust to reach the observer.
I completely agree that this does not violate causality.
BUT
This is not the explanation i found around. What i found (and which was
answered around here as well) is that the stretching doesn't have to travel
from the pulling ship through the wire until the wire breaks, but that the
whole length of the wire changes "simultaneously" (this is probably not the
best word) in spacetime. Meaning, the increase in proper distance doesn't
take time to travel from the front ship to the breakage point.
Again, your description seems rather classical, and the breakage is always
observed after both engines started.
If that is really the correct answer, then i understand why there is no
causality violation. But vertical seems to believe what i have concluded as
well: that there are frames in which the breakage occurs before the second
ship fires up.

To point out another, lesser issue i see in your explanation, think about
the frame where the rear ship fires first: the wire is compressed a bit
before the front ship ignites.
In the frame where the front ship pulls first, the wire surely CAN break
before the rear ship is seen to ignite, hence there is no compression in
this frame. The only way i see to deal with this disagreement is to take
this compression as a regular LC (as in inertial frames) where no physical
process is not altered. But since this is a non-inertial frame, i remain
puzzled.

Could you clarify further?

rotchm

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May 24, 2013, 2:36:46 PM5/24/13
to
On May 24, 2:04 pm, altergnostic <altergnos...@gmail.com> wrote:

> I completely agree that this does not violate causality.
> BUT
> This is not the explanation i found around.


Lets see the toher explanation...

> What i found (and which was
> answered around here as well) is that the stretching doesn't have to travel
> from the pulling ship through the wire until the wire breaks,

yes it does.

> but that the
> whole length of the wire changes "simultaneously" in spacetime.

No it doesnt. Thast description is a *simplified* and perhaps naive
description of the process. The laws of physics must apply; there are
no 'rigid' things according to SR; the wire is stretchable.

> Meaning, the increase in proper distance doesn't
> take time to travel from the front ship to the breakage point.

The 'naive' description is that eventually, when the ships have
attained their final speed and so as the wire, the wire is Lorentz
contracted. But since we posit that we ant to 'force' it to maintain
the full length, then those two effects are incompatible: eventually
the wire breaks. You dont need the intermolecular cohesion description
to conclude that the wire will break. But if you want a full analysis,
you do need to consider it.

> Again, your description seems rather classical,

It might seem that to you but it is a fully relativistic description.
Actually, in classical mechanics the wire will stretch and break
too...but thats a different topic.

> and the breakage is always
> observed after both engines started.
> If that is really the correct answer, then i understand why there is no
> causality violation.

There you go.

> But vertical seems to believe what i have concluded as
> well: that there are frames in which the breakage occurs before the second
> ship fires up.

The wire breaks always after the pulling ship, in all frames. In S
frame:

E1:Front ship starts pulling @ t1
E2: wire breaks @ t2

dt' = g(dt - dx*v/c2). But dt >= dx/c (causal, it breaks after
pulling in S), thus

dt = g(dt - c*dt*v/c2) = d*dt*(1 - v/c) >= 0 for all v.

Note_1: For E3 = back ship starts 'pushing' @ t3 = t1 (it is
simultaneous in S).
Thus dt for these two events is 0 thus dt' can be < 0. But this is not
what you are looking for. You are concerned with the breakage which
is not simul to t1 = 0 in S.

Note_2: But again, even pushing (squishing and destroying) will break
the wire if one assumes its rigid, which is no longer part of our
discussion since nothing is rigid.


> To point out another, lesser issue i see in your explanation, think about
> the frame where the rear ship fires first: the wire is compressed a bit
> before the front ship ignites.

Yes, as hinted in Note_1.

> In the frame where the front ship pulls first, the wire surely CAN break
> before the rear ship is seen to ignite,


yes.

> hence there is no compression in this frame.

None yet, and is, a priori, not needed.

> The only way i see to deal with this disagreement

I see no disagreement here. All works out fine.


> is to take this compression as a regular LC (as in inertial frames) where no physical
> process is not altered. But since this is a non-inertial frame, i remain
> puzzled.
>
> Could you clarify further?

Just did. But perhaps a note_3: "this" is a non-frame? Which one? S is
inertial so as S', the final steadystate frame. You can describe the
EM intemolecular stretching/compression via any iframe. You cant
readily describe the effects via non iframe, but thats a different
subject.

Paul Cardinale

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May 24, 2013, 10:17:50 PM5/24/13
to
On May 23, 10:44 pm, "Lord Androcles, Zeroth Earl of Medway"
<LordAndroc...@May2013.edu> wrote:
> "Paul Cardinale"  wrote in message
>
> news:86af2d23-0e96-4fb3...@k4g2000yqb.googlegroups.com...
>
> On May 22, 2:15 pm, "Lord Androcles, Zeroth Earl of Medway"
>
> <LordAndroc...@May2013.edu> wrote:
> > "Paul Cardinale"  wrote in message
>
> >news:9bb93a4f-d96d-4ed7...@s6g2000yqs.googlegroups.com...
>
> > On May 22, 9:12 am, "Lord Androcles, Zeroth Earl of Medway"
>
> > <LordAndroc...@May2013.edu> wrote:
> > ==============================================
> > Here once again the fucking idiot and total MORON Crapinale is
> > utterly incapable of understanding what a coordinate transformation
> > is.  A ruler of length 0 cm to 30 cm ...
>
> AND YET AGAIN! "A ruler of length 0 cm to 30 cm ..." is perfect
> demonstration that he just can't grasp the difference between
> coordinates and distance!
> ====================================================
> Okay, you stupid fuck,  why don't you tell is all what the x, y ands z
> coordinates of a school ruler are and the what the "difference" is?

So you flat-out admit that you don't know the difference between
'coordinates' and 'distance', right?

rotchm

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May 24, 2013, 10:44:02 PM5/24/13
to
On May 24, 2:36 pm, rotchm <rot...@gmail.com> wrote:

> dt' = g(dt - dx*v/c2). But dt >= dx/c  (causal, it breaks after
> pulling in S), thus
>
> dt = g(dt - c*dt*v/c2) = d*dt*(1 - v/c) >= 0 for all v.

A few typo's here. It should read dt' = ... = g*dt*(1-v/c) >=0 ...

Earl Wagner

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May 25, 2013, 3:15:33 AM5/25/13
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You are all too much indulgent with the "few", much less "typo's"

Lord Androcles, Zeroth Earl of Medway

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May 25, 2013, 3:17:22 AM5/25/13
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"Paul Cardinale" wrote in message
news:59de74ae-07bd-4067...@w8g2000yqf.googlegroups.com...
=====================================================


You asked about coordinates and length, not coordinates and distance,
you clueless ignorant cunt.
So you flat-out admit that you don't know the difference between
'length' and 'distance', right, ARSEHOLE?
Why don't you tell is all what the x, y ands z coordinates of a school
ruler are and what the "difference" is, you useless bullshitting bastard?

Earl Wagner

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May 25, 2013, 3:32:18 AM5/25/13
to
Lord Androcles, Zeroth Earl of Medway wrote:

> You asked about coordinates and length, not coordinates and distance,
> you clueless ignorant cunt.
> So you flat-out admit that you don't know the difference between
> 'length' and 'distance', right, ARSEHOLE?

Neither do I, what is the difference?

> Why don't you tell is all what the x, y ands z coordinates of a school
> ruler are and what the "difference" is, you useless bullshitting bastard?

Angles? This is all greek for me.

Lord Androcles, Zeroth Earl of Medway

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May 25, 2013, 4:32:17 AM5/25/13
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"Earl Wagner" wrote in message news:knppe2$g7d$3...@speranza.aioe.org...

Lord Androcles, Zeroth Earl of Medway wrote:

> You asked about coordinates and length, not coordinates and distance,
> you clueless ignorant cunt.
> So you flat-out admit that you don't know the difference between
> 'length' and 'distance', right, ARSEHOLE?

Neither do I, what is the difference?
===============================
The complete moron Crapinale claims the " formula for length
contraction is something different than the formula for a coordinate
transform" but the arsehole can't say what it is because the
useless cunt knows no algebra and can only insult others. Nor
does the stupid fuck wish to learn, he's spent the last decade
writing one line vicious stabs at others.
You can fuck off too, nymshifting troll.
*plonk*

Earl Wagner

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May 25, 2013, 4:35:58 AM5/25/13
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Lord Androcles, Zeroth Earl of Medway wrote:

> You can fuck off too, nymshifting troll.
> *plonk*

I didn't knew you feel that much. I asked kindly about the difference.

altergnostic

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May 25, 2013, 1:26:19 PM5/25/13
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rotchm <rot...@gmail.com> wrote:
> On May 24, 2:04 pm, altergnostic <altergnos...@gmail.com> wrote:

>
>> In the frame where the front ship pulls first, the wire surely CAN break
>> before the rear ship is seen to ignite,
>
>
> yes.
>
>> hence there is no compression in this frame.
>
> None yet, and is, a priori, not needed.
>
>> The only way i see to deal with this disagreement
>
> I see no disagreement here. All works out fine.
>


Thanks for the thorough reply.
You agreed that there is a frame in which compression occurs before
breakage and another in which there isn't any compression before the wire
breaks. Don't you see the disagreement in that?
Everything else is clarified (except the fact that vertical seems to
believe in the existence of frames in which the wire breaks before the
front ship ignites, i wish he addressed this over here).

rotchm

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May 25, 2013, 2:53:46 PM5/25/13
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On May 25, 1:26 pm, altergnostic <altergnos...@gmail.com> wrote:

> Thanks for the thorough reply.
> You agreed that there is a frame in which compression occurs before
> breakage

... in the sense that the ship starts pushing before the pulling ship.

> and another in which there isn't any compression before the wire
> breaks.

Not necessarily. It depends on the acceleration of the pulling ship
and the speed of propagation of the pulling in the wire. The wire can
break before that point receives the compression.

No matter when the pushing will occur (in the other frames), the
breakage will always be after the pulling ship.

> Don't you see the disagreement in that?

Nope.

> Everything else is clarified (except the fact that vertical seems to
> believe in the existence of frames in which the wire breaks before the
> front ship ignites, i wish he addressed this over here).

I gave you the math. dt' = g(dt - dx*v/c2) >=0 since dt>= dx/c
(causal) in S.

But he can be right if, *if* we assume that pushing can break the
wire. Recall that materials can have different breaking features
depending if they are pulled or pushed. But this is a different story.

Paul Cardinale

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May 25, 2013, 4:16:40 PM5/25/13
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On May 25, 1:32 am, "Lord Androcles, Zeroth Earl of Medway"
<LordAndroc...@May2013.edu> wrote:
> "Earl Wagner"  wrote in messagenews:knppe2$g7d$3...@speranza.aioe.org...
>
> Lord Androcles, Zeroth Earl of Medway wrote:
>
> > You  asked about coordinates and length, not coordinates and distance,
> > you clueless ignorant cunt.
> > So you flat-out admit that you don't know the difference between
> > 'length' and 'distance', right, ARSEHOLE?
>
> Neither do I, what is the difference?
> ===============================
> The complete moron Crapinale claims the " formula for length
> contraction is something different than the formula for a coordinate
> transform"

Aw. Still angry because you can't tell the difference and no one
wants to try to explain it to a stupid puke like you?
I and many others would be happy to explain it to someone civil.

Dirk Van de moortel

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May 25, 2013, 4:40:13 PM5/25/13
to

Lord Androcles, Zeroth Earl of Medway

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May 25, 2013, 4:55:00 PM5/25/13
to
"Paul Cardinale" wrote in message
news:855381dc-6079-4017...@k4g2000yqb.googlegroups.com...

On May 25, 1:32 am, "Lord Androcles, Zeroth Earl of Medway"
<LordAndroc...@May2013.edu> wrote:
> "Earl Wagner" wrote in messagenews:knppe2$g7d$3...@speranza.aioe.org...
>
> Lord Androcles, Zeroth Earl of Medway wrote:
>
> > You asked about coordinates and length, not coordinates and distance,
> > you clueless ignorant cunt.
> > So you flat-out admit that you don't know the difference between
> > 'length' and 'distance', right, ARSEHOLE?
>
> Neither do I, what is the difference?
> ===============================
> The complete moron Crapinale claims the " formula for length
> contraction is something different than the formula for a coordinate
> transform"

Aw. Still angry
===================================
So you flat-out admit that you don't know the difference between
'length' and 'distance', right, ARSEHOLE?

Paul Cardinale

unread,
May 26, 2013, 10:33:21 AM5/26/13
to
On May 25, 1:55 pm, "Lord Androcles, Zeroth Earl of Medway"
Apparently you don't know the meaning of the word "admit". Do you
know the meanings of even 10% of the words you use?

Lord Androcles, Zeroth Earl of Medway

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May 26, 2013, 11:32:03 AM5/26/13
to
"Paul Cardinale" wrote in message
news:db58dc85-3cdf-494e...@d6g2000yqi.googlegroups.com...
===================================================
AND YET AGAIN!
So you flat-out admit that you don't know the difference between
'length' and 'distance', right, ARSEHOLE?

-- ==============================================
Commiserations, Crapinale! You have managed to produce a one-line insult,
your only capability.
The miserable putrid scum Paul Cardinale can only resort to lies when
confronted with
his own rank stupidity.
The world will be a better place, the average happiness and the average IQ
of the
human race will rise markedly on the day the Porkie Crapinale dies.

Tom Roberts

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May 26, 2013, 2:51:28 PM5/26/13
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On 5/22/13 5/22/13 8:58 AM, altergnostic wrote:
> [Bell's spaceships and wire paradox]
> There are frames in which the front ship fires it's engines before the rear
> one, a frame in which they do so simultaneously and frames in which the
> rear ship fires before the front one.[...]

There has been much heat and misinformation in this thread, and a few hints at
the resolution, but no clear answer.


The basic problem is that the naive causality you seek is not present in the
fundamental theories of modern physics, it is at best an APPROXIMATION. Granted,
in our everyday lives the approximation is very good, but it remains an
approximation, and certainly is not any fundamental "law" of nature (as you seem
to think).

Indeed, all physical theories since Newton have been expressed in terms of
differential equations, which lack any sort of causality in the sense you seek
-- one cannot claim "this force caused that mass to accelerate", because the
equations only describe the CORRELATION between the force and the acceleration,
and correlation is not causation -- while people do say things like that, they
are imposing personal interpretations not present in the equations.

This mode of speaking presumably arose via analogy with how we
humans modify our world: we personally cause things to move by
using our bodies to exert a force on them. HUMANS have this
causality in our minds and inappropriately project it onto the
world in general.

Your insistence on "causality" is a major part of your confusion about modern
physics. You are emotionally/psychologically projecting how you personally
behave onto the world at large; that's invalid.

Two key points:

1. In the Bell paradox, the starting of the two spaceships are events with
a SPACELIKE separation. This means they have no coordinate-independent
time order, and that they are not causally connected [#].
2. All physics is local.

[#] This is NOT your naive causality. This means that whatever
happens at point P cannot be influenced by any happening outside
the past lightcone of P.

#2 means that if you want to consider how and where and why the wire breaks, you
must examine the strain at the inter-atomic bonds between each and every pair of
atoms in the wire. This goes FAR beyond the elementary teaching example, because
the tension in the wire is passed atom-to-atom by these bonds, until enough of
them are over-strained and the wire breaks; that is a complex dynamical problem.
But I can make a few remarks about it:
A) each bond must be analyzed in its instantaneously co-moving inertial
frame.
B) as the spaceships (measured "now" in the frame of A) are spacelike
separated from the bond in question, they aren't the "cause" of the
bond breaking.
C) but the neighboring bonds are right there, transferring strain to this
bond.

So when the wire breaks at some point, all one can say is that it broke there
because of the strain transferred to that point. Attempting to "trace a chain of
causality" back to the rockets is difficult at best and quite useless, because
of all the spacelike separations. No matter: every observer will agree that the
wire broke because of the strain right at the point where it broke.


Tom Roberts

altergnostic

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May 27, 2013, 7:49:24 AM5/27/13
to
I disagree with such line of reasoning. It isn't emotion or psychology that
supports causality, but evidence that one thing causes the next - which
yields the forwarding of time - and that nothing is uncaused (which can't
be proven).
There can be no evidence against causality. We can only propose a cause and
falsify it, but to propose no cause is to accept an open ended reasoning as
fact, since it will always be possible that we simply haven't found out
what the cause actually is. As far as i'm concerned, this is just a
hypothesis that you (and others) find compelling, but i don't.

Are you familiar with the Black Swan's Logic? You can only prove that all
swan's are white if you have the whole population of swans for a sample,
otherwise there may be a black swan outside your sample. But then, you
can't prove that your sample contains all the swans, for that requires you
have looked in all possibles places at the same time.
In one line, such assertion requires omniscience, which no human will ever
achieve, of course.
There is no cause = there is no black swan.

>
> Two key points:
>
> 1. In the Bell paradox, the starting of the two spaceships are events with
> a SPACELIKE separation. This means they have no coordinate-independent
> time order, and that they are not causally connected [#].
> 2. All physics is local.
>
> [#] This is NOT your naive causality. This means that whatever
> happens at point P cannot be influenced by any happening outside
> the past lightcone of P.

Yes, and I agree. I never said one ship causes the other to ignite, that
would be ridiculous.

>
> #2 means that if you want to consider how and where and why the wire
> breaks, you must examine the strain at the inter-atomic bonds between
> each and every pair of atoms in the wire. This goes FAR beyond the
> elementary teaching example, because the tension in the wire is passed
> atom-to-atom by these bonds, until enough of them are over-strained and
> the wire breaks; that is a complex dynamical problem. But I can make a
> few remarks about it:
> A) each bond must be analyzed in its instantaneously co-moving inertial
> frame.
> B) as the spaceships (measured "now" in the frame of A) are spacelike
> separated from the bond in question, they aren't the "cause" of the
> bond breaking.
> C) but the neighboring bonds are right there, transferring strain to this
> bond.
>
> So when the wire breaks at some point, all one can say is that it broke
> there because of the strain transferred to that point. Attempting to
> "trace a chain of causality" back to the rockets is difficult at best and
> quite useless, because of all the spacelike separations. No matter: every
> observer will agree that the wire broke because of the strain right at
> the point where it broke.
>

The statement "it's hard to follow a line of causes" is not an argument.
Rotchm was the only one so far who said anything plausible, which is that
there is no possible frame in which the wire breaks before both ships have
started. Veryical stated otherwise. What's your input on this? Is there a
frame in which the wire breaks before one of the ships have started or not?

>
> Tom Roberts

shuba

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May 27, 2013, 2:03:34 PM5/27/13
to
altergnostic wrote:

> Is there a frame in which the wire breaks before one of the ships
> have started or not?

It is possible to consider (rather contrived) scenarios in which
the start of *one* particular ship is spacelike separated from the
breaking of the wire. For those cases there is no causal chain of
events including those two events. The ignition of the two ships
cannot both be spacelike separated from the breaking of the wire
(unless there is some as yet unstated alternative causal chain
unaffected by the firing (or not) of the engines on either ship).


---Tim Shuba---

Absolutely Vertical

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May 28, 2013, 9:09:17 AM5/28/13
to
On 5/23/2013 6:52 PM, altergnostic wrote:
> Absolutely Vertical <absolutel...@gmail.com> wrote:

>> sure, let me be direct. the rod will only hit _one_ of the shutters, the
>> one at the back of the back of the box, and the front of the pole will
>> hit it from the inside of the box.
>>
>> but the other shutter will not close on the pole. there will be no mark
>> on either the pole or the shutter from a collision between the two.
>>
>> the question now is how to account for _why_. (the cause, if you like.)
>> do this from the frame of the box, and then do it from the frame of the pole.
>
> Let's assume the rod hits the shutter and passes right through it. In the
> frame of the box, the rod fits inside the box, so when both shutters close,
> the rod is completely inside, as it continues to move forward, it hits the
> front shutter. The shutter on the back never touched the rid.
> In the frame of the rod, it passes through the first shutter, which closes
> after the back end of the rod has already passed through. The front end
> hits the second shutter before the first shutter closes.
> I don't see any disagreement in the line of causes. Consider a setup in
> which the rod breaks if it hits a shutter. All frames agree that it does so
> because it hits the front one, not the back one.
>

that's not really the question.
the shutters are open when the box approaches, and then they close.
in the frame of the box, the rod is shorter than the box and there is an
impact when the front of the rod hits one of the shutters from inside
the box. but the other shutter doesn't hit the rod, even though it
closes at the same time as the first one, because the rod is shorter
than the box and the whole rod is now inside the box.
in the frame of the rod, though, the rod is much longer than the box,
and so the accounting (the cause, if you like) for why the back end of
the rod isn't hit by the shutter must be different. here, the other
shutter doesn't close at the same time as the first one. that's not
enough because if the rod is longer than the box, it doesn't matter when
the shutter closes. but what is true in this frame is that the back of
the rod keeps moving even when the front of the rod has stopped, because
the news that the front of the rod has been stopped takes a while to
propagate to the back of the rod. this little while is enough that the
back of the rod passes into the interior of the box before the shutter
closes, and that is the reason why the back shutter doesn't hit the rod.

altergnostic

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May 28, 2013, 9:43:56 AM5/28/13
to
I see, but let me ask you this: when the rod completely stops, does it
expand back and hits the rear shutter from inside the box?

Absolutely Vertical

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May 28, 2013, 12:46:05 PM5/28/13
to
not necessarily. why do you think this is important to answer?
perhaps we could deal with the different in the accounting of the
observations listed above....

altergnostic

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May 28, 2013, 7:14:53 PM5/28/13
to
Why do i think it's important?? Why don't you?
See, if it expands back and hits the back side of box from inside it
*necessarily* means that the contraction represented a very real change of
state, it should be clear it corresponds to a change in physical processes,
the rod would suffer tension and all the effects that come with it, the
extension yields a real force and the back end of the rod would accelerate
at the same rate as the rod decelerates, and such extension should even
cause a recoil, making the rod's elasticity work against the equal and
opposite force until the rod achieves equilibrium and the length is
stabilized.
It follows that the relativistic length contraction and the subsequent
expansion could be used to transfer energy. This is a direct contradiction
of the "no change in physical processes" claim, isn't it?

Absolutely Vertical

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May 29, 2013, 7:00:29 AM5/29/13
to
On 5/28/2013 6:14 PM, altergnostic wrote:
>>> I see, but let me ask you this: when the rod completely stops, does it
>>> >>expand back and hits the rear shutter from inside the box?
>>> >>
>> >
>> >not necessarily. why do you think this is important to answer?
>> >perhaps we could deal with the different in the accounting of the
>> >observations listed above....
> Why do i think it's important?? Why don't you?
> See, if it expands back and hits the back side of box from inside it
> *necessarily* means that the contraction represented a very real change of
> state, it should be clear it corresponds to a change in physical processes,
> the rod would suffer tension and all the effects that come with it, the
> extension yields a real force and the back end of the rod would accelerate
> at the same rate as the rod decelerates, and such extension should even
> cause a recoil, making the rod's elasticity work against the equal and
> opposite force until the rod achieves equilibrium and the length is
> stabilized.

then my previous answer should serve it's purpose. it does not
necessarily expand backwards.

altergnostic

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May 29, 2013, 1:01:05 PM5/29/13
to
Are you saying the length that was contracted due to relative motion
remains contracted when the rod comes to a stop?

Absolutely Vertical

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May 29, 2013, 1:14:14 PM5/29/13
to
no, i'm not saying that. however, it would then be false to say that the
real and necessary implication would then be that a rod decelerated to a
stop would then result in the back end of the rod reversing direction
and going backwards so that the rod resumes its rest length.

such a circumstance would rely on the deceleration being less than the
elastic limit of the rod, that the signal propagating backwards with the
news that the front end has stopped is an elastic and restorative signal
rather than a shock wave, and so on. and that is not a necessary
conclusion at all. in fact, it may be worthwhile to compare the kinetic
energy of a rod moving this fast with the stored configuration energy
that binds the rod together as a solid.

special relativity doesn't dismiss other laws of physics, such as those
governing the binding of solid materials. you can get into considerable
trouble idealizing a situation too much so that you can trace the
implication of one law of physics, while completely violating another.

so special relativity is fine with the rod collapsing (or vaporizing)
upon impact.

but back to the original point of this example. do you see any problem
with the two different accounts for why the second shutter did not make
contact with the rod? does this in any way 'violate causality' for you,
in that two completely different causes are given for the observed outcome?

Absolutely Vertical

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May 29, 2013, 1:36:09 PM5/29/13
to
On 5/29/2013 12:01 PM, altergnostic wrote:
see my previous response to this.

but let's take for giggles the very limited case where the slowing
stress is less than the elastic limit of the rod, and that there is a
touching of the inside of the second shutter by the back end of the rod.
how is this accounted for?

in the frame of the box, the back end of the rod continues to proceed
forward until the signal of the impact by the front of the rod has made
its way to the back of the rod. this then causes backwards acceleration
of the back of the rod, so that the back end of the rod changes
direction of motion and retreats to the back of the box, where it
encounters the closed shutter. there it is trapped and the rod
experiences a compressional stress, held by both shutters.

in the frame of the rod, the back end of the rod is not moving of course
and still does not move when the first closed shutter impacts the front
of the rod. the signal of this impact progresses backwards through the
rod. meanwhile, notice that one end of the moving box has been stopped
by the front of the rod and the other end of the moving box continues to
slide past the rod, the second shutter still open, for exactly the same
reasons the two ends of the rod don't stop simultaneously. shortly after
the second shutter opening passes the back end of the rod, the second
shutter closes. meanwhile, the signal propagating from the front of the
rod has made its way to the back of the rod and the back of the rod
accelerates rearward, just like the last ball in a newton's cradle. the
back of the rod encounters the closed shutter and the rod is now shorter
(compressed) because the front of the rod started accelerating backwards
before the back of the rod did. the rod is now trapped in compressive
stress inside the box.

same outcome: rod inside the box, trapped by shutters in compressive
stress. two different accounts for _why_ it ended up in this state. does
this violate causality for you?

Absolutely Vertical

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May 29, 2013, 1:41:50 PM5/29/13
to
On 5/29/2013 12:36 PM, Absolutely Vertical wrote:
> On 5/29/2013 12:01 PM, altergnostic wrote:

>>
>> Are you saying the length that was contracted due to relative motion
>> remains contracted when the rod comes to a stop?
>>
>
> see my previous response to this.
>
> but let's take for giggles the very limited case where the slowing
> stress is less than the elastic limit of the rod, and that there is a
> touching of the inside of the second shutter by the back end of the rod.
> how is this accounted for?
>
...
>
> same outcome: rod inside the box, trapped by shutters in compressive
> stress. two different accounts for _why_ it ended up in this state. does
> this violate causality for you?

and just as a pedagogical meta-comment, let me remind you that i have
not made anything up in the accounts of the two perfectly real outcomes
described here. in fact, had you been reading mainstream materials about
relativity as you say you have, you would have already encountered
descriptions with this level of detail. so consider it simply a reminder
that you really should invest the time and effort to read quality
materials about relativity, so that you will understand it better than
you do.

altergnostic

unread,
May 29, 2013, 1:51:30 PM5/29/13
to
Absolutely Vertical <absolutel...@gmail.com> wrote:
>>
>> Are you saying the length that was contracted due to relative motion
>> remains contracted when the rod comes to a stop?
>>
>
> no, i'm not saying that.
Just checking.

>however, it would then be false to say that the real and necessary
> implication would then be that a rod decelerated to a stop would then
> result in the back end of the rod reversing direction and going backwards
> so that the rod resumes its rest length.
>
> such a circumstance would rely on the deceleration being less than the
> elastic limit of the rod, that the signal propagating backwards with the
> news that the front end has stopped is an elastic and restorative signal
> rather than a shock wave, and so on. and that is not a necessary
> conclusion at all. in fact, it may be worthwhile to compare the kinetic
> energy of a rod moving this fast with the stored configuration energy
> that binds the rod together as a solid.
>
> special relativity doesn't dismiss other laws of physics, such as those
> governing the binding of solid materials. you can get into considerable
> trouble idealizing a situation too much so that you can trace the
> implication of one law of physics, while completely violating another.
>
> so special relativity is fine with the rod collapsing (or vaporizing) upon impact.
>
> but back to the original point of this example. do you see any problem
> with the two different accounts for why the second shutter did not make
> contact with the rod? does this in any way 'violate causality' for you,
> in that two completely different causes are given for the observed outcome?

Not at all. I'll reply to your other post.

altergnostic

unread,
May 29, 2013, 1:58:30 PM5/29/13
to
No, but it does say that these effects are real changes in physical
processes. Surely, they are allowed because they occur in non-inertial
circumstances (during accel).
In any case, these descriptions are not incompatible with each other:
everyone agrees that the force is generated in the front if the rod first,
and that the back shutter keeps the rod from expanding. The other effects
could even be regarded as apparent effects (frame dependent quantities),
but not real changes in physical processes, since these are not changes at
all, the changes are only introduced when frames become non-inertial.

Absolutely Vertical

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May 29, 2013, 2:45:08 PM5/29/13
to
well, just about any laws of dynamical interactions involve
accelerations (including the electromagnetic ones that got this whole
business of relativity going) and all those dynamical interactions
respect relativity, so this should not be a surprise.

as a comment to your last nine words, let me point out that very little
if anything of my descriptions changes if you stick to inertial frames.
the frame of the rod in that case would be the frame that moving along
with the rod prior to impact and continues inertially. thus any changes
you see should be treated as you would if we were looking at inertial
frames.

as to your comment about real vs apparent effects, all of the different
accounts given are obviously frame dependent. since i have no idea what
you mean by 'real changes in physical processes' and since the
descriptions i have given you involve real dynamical processes, though
the descriptions are different in different frames, i would be hesitant
to call any of them 'apparent'.

Absolutely Vertical

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May 29, 2013, 3:16:49 PM5/29/13
to
On 5/29/2013 12:51 PM, altergnostic wrote:
>> but back to the original point of this example. do you see any problem
>> >with the two different accounts for why the second shutter did not make
>> >contact with the rod? does this in any way 'violate causality' for you,
>> >in that two completely different causes are given for the observed outcome?
>
> Not at all. I'll reply to your other post.

good. then i think you and i agree that having different accounts for
chains of events and ascribing frame-dependent causes to them has
nothing whatsoever to do with violating causality or causing any kind of
causality mess.

altergnostic

unread,
May 31, 2013, 1:23:35 PM5/31/13
to
That depends, Vert.
One thing is to have two different descriptions to the same thing, where
everyone agrees that the rod and the back shutter hit each other from the
inside, independently of the order of events - the forces are the same.
Another, is when someone thinks they hit eachother from outside and someone
else from the inside. Or, back to our problem, that the wire broke because
ship 2 ignited or because ship 1 did.

altergnostic

unread,
May 31, 2013, 2:01:28 PM5/31/13
to
By real changes in physical processes i mean effects like boiling water.
Length contraction can't boil water, because water has to boiling in all
frames, and these are the kind of changes i refer to, they are frame
independent and the body itself feels them, so everyone agrees they are
real. Length contraction is not a *change* that *occurs* in inertial
frames, the length suffer changes only in non-inertial frames. Is that a
bit clearer?

Absolutely Vertical

unread,
May 31, 2013, 2:05:19 PM5/31/13
to
On 5/31/2013 12:23 PM, altergnostic wrote:

>
> That depends, Vert.
> One thing is to have two different descriptions to the same thing, where
> everyone agrees that the rod and the back shutter hit each other from the
> inside, independently of the order of events - the forces are the same.

the striking of the shutters on the ends of the pole are observable
outcomes, which are always independent of observer. however, the
accounting of how those observable outcomes arose is different, that is,
the _causes_ of the events.

> Another, is when someone thinks they hit eachother from outside and someone
> else from the inside. Or, back to our problem, that the wire broke because
> ship 2 ignited or because ship 1 did.
>

the observable outcome of the bell puzzle is that the wire broke when it
experienced stress at its anchor points. this is the outcome that is
analogous to the marks on the shutters from the ends of the poles and
the stress between the shutter and the ends of the poles. however, the
accounting for the cause outcome is what varies from frame to frame, and
this is exactly analogous to the different accounts of the cause for the
analogous outcomes in the pole and box case.

it will help too to notice the distinction between two pairs of events
in the pole and box case.
pair 1: the closings of the two shutters at the opposite ends of the box.
pair 2: the signal of the impact at the front of the pole, and that
signal arriving at the back of the pole.

in the first pair, the two events are spacelike-separated and in the
second pair, the two events are timelike-separated. this has important
physical consequences, as i'm sure you're aware.


altergnostic

unread,
May 31, 2013, 5:18:42 PM5/31/13
to
Absolutely Vertical <absolutel...@gmail.com> wrote:
> On 5/31/2013 12:23 PM, altergnostic wrote:
>
>>
>> That depends, Vert.
>> One thing is to have two different descriptions to the same thing, where
>> everyone agrees that the rod and the back shutter hit each other from the
>> inside, independently of the order of events - the forces are the same.
>
> the striking of the shutters on the ends of the pole are observable
> outcomes, which are always independent of observer. however, the
> accounting of how those observable outcomes arose is different, that is,
> the _causes_ of the events.

Yes, of course. As i said, one thing is to say that everyone agrees that
rod and shutter meet from the inside of the box, another is to state that
two observers will differ about which ship did the damage. If the rod broke
in two, it would be like disagreeing if it was because it hit shutter A
(and broke before contact with shutter B) or the reverse. These are not
different causes, they are different observations.

Tom Roberts

unread,
Jun 2, 2013, 8:53:39 AM6/2/13
to
On 5/27/13 5/27/13 6:49 AM, altergnostic wrote:
> Tom Roberts <tjrobe...@sbcglobal.net> wrote:
>> [...]
>> Your insistence on "causality" is a major part of your confusion about
>> modern physics. You are emotionally/psychologically projecting how you
>> personally behave onto the world at large; that's invalid.
>
> I disagree with such line of reasoning. It isn't emotion or psychology that
> supports causality, but evidence that one thing causes the next

I repeat: this applies ONLY at the scale of human beings, and ONLY for VERY
casual observations. At the atomic and subatomic scale there is NO EVIDENCE FOR
YOUR NAIVE CAUSALITY. Indeed, there is LOTS of evidence against it.

Unstable particles decay, with no discernible "cause".


> There can be no evidence against causality.

This is just plain wrong, displaying your non-scientific motives. If this were
true, then your naive causality could not be a scientific theory. The basic
problem is that you do not have a TESTABLE theory that includes your naive
causality. Note that interactions among elementary particles are extremely well
modeled by theories without any hint of your naive causality. Evidence for
non-causal theories, which is legion, is also evidence against your naive causality.

When you insist on ignoring experimental evidence like that, then you are not
doing science. Your personal dreams and prejudices are IRRELEVANT to science.
And yours are just plain wrong, presumably due to your ignorance and illiteracy
in the subject.

Your "black swan" discussion also shows that you are not interested in science.
The analogy there is that the MODEL "there are no black swans here" is accurate
for a population of swans being observed in a reasonable region. A scientist
recognizes that she cannot possibly search the entire universe for black swans,
but she CAN search her local area, AND THAT IS ALL THAT IS NEEDED FOR SUCH A MODEL.


> Is there a
> frame in which the wire breaks before one of the ships have started or not?

That's irrelevant. There is no frame in which the wire breaks between a given
pair of atoms, such that the break occurs before the adjacent atoms have exerted
a strain on the inter-atomic bond in question.


Tom Roberts

Lord Androcles, Zeroth Earl of Medway

unread,
Jun 2, 2013, 9:06:55 AM6/2/13
to
"Tom Roberts" wrote in message news:bcednbR4xJb...@giganews.com...

On 5/27/13 5/27/13 6:49 AM, altergnostic wrote:
> Tom Roberts <tjrobe...@sbcglobal.net> wrote:
>> [...]
>> Your insistence on "causality" is a major part of your confusion about
>> modern physics. You are emotionally/psychologically projecting how you
>> personally behave onto the world at large; that's invalid.
>
> I disagree with such line of reasoning. It isn't emotion or psychology
> that
> supports causality, but evidence that one thing causes the next

I repeat: this applies ONLY at the scale of human beings, and ONLY for VERY
casual observations. At the atomic and subatomic scale there is NO EVIDENCE
FOR
YOUR NAIVE CAUSALITY. Indeed, there is LOTS of evidence against it.
===================================================

-- Note to readers: Humpty Roberts, mincer of words, is among
the most persistent LYING idiots around here. He has been
repeating this nonsense for many years, without any attempt
to learn the subject he tries to write about. I reply to him only
occasionally, as a service to readers who may not recognize
his lies.
He has proven himself to be unable and unwilling to learn
anything, including physics, algebra and Einstein's paper.

altergnostic

unread,
Jun 2, 2013, 2:40:41 PM6/2/13
to
Tom Roberts <tjrobe...@sbcglobal.net> wrote:
> On 5/27/13 5/27/13 6:49 AM, altergnostic wrote:

>>
>> I disagree with such line of reasoning. It isn't emotion or psychology that
>> supports causality, but evidence that one thing causes the next
>
> I repeat: this applies ONLY at the scale of human beings, and ONLY for
> VERY casual observations. At the atomic and subatomic scale there is NO
> EVIDENCE FOR YOUR NAIVE CAUSALITY. Indeed, there is LOTS of evidence against it.
>
> Unstable particles decay, with no discernible "cause".
>
>
>> There can be no evidence against causality.
>
> This is just plain wrong, displaying your non-scientific motives. If this
> were true, then your naive causality could not be a scientific theory.
> The basic problem is that you do not have a TESTABLE theory that includes
> your naive causality. Note that interactions among elementary particles
> are extremely well modeled by theories without any hint of your naive
> causality. Evidence for non-causal theories, which is legion, is also
> evidence against your naive causality.

But it isn't a scientific theory, it's a logical formalism which was
originally one of the *aums* of science, and it isn't mine either. What did
you think causality was?

>
> When you insist on ignoring experimental evidence like that, then you are
> not doing science. Your personal dreams and prejudices are IRRELEVANT to
> science. And yours are just plain wrong, presumably due to your ignorance
> and illiteracy in the subject.
>
> Your "black swan" discussion also shows that you are not interested in
> science. The analogy there is that the MODEL "there are no black swans
> here" is accurate for a population of swans being observed in a
> reasonable region. A scientist recognizes that she cannot possibly search
> the entire universe for black swans, but she CAN search her local area,
> AND THAT IS ALL THAT IS NEEDED FOR SUCH A MODEL.

Indeed! So keep looking for a cause til you find one or propose how
something is generated without a cause without violating any rules of
logic. To have discovered no cause will never be proof that there is no
cause, especially when dealing with relatively new fields of science with
relatively new technology.

But why are we even discussing this, Tom? Aren't the ships and wires at
human scale after all? Have macro objects and human scales interactions
ever cheated causality in any experiment?
>
>
>> Is there a
>> frame in which the wire breaks before one of the ships have started or not?
>
> That's irrelevant. There is no frame in which the wire breaks between a
> given pair of atoms, such that the break occurs before the adjacent atoms
> have exerted a strain on the inter-atomic bond in question.
>
>
> Tom Roberts

No need to dodge into the subatomic realm, since they are not necessary to
solve the problem. Where precisely it breaks and how many atoms have felt
strain near the breakage is what's really irrelevant. All we need to know
is which ignition event is causally related to the breakage - if you still
believe it needs a cause, because if you think the wire can break
spontaneously i don't even know why we are discussing possible scenarios
and outcomes, really.

Tom Roberts

unread,
Jun 3, 2013, 11:47:37 AM6/3/13
to
On 5/31/13 5/31/13 - 1:01 PM, altergnostic wrote:
> [... length contraction ...]
> By real changes in physical processes i mean effects like boiling water.

Analogy: When you walk away from me, you APPEAR to get smaller. This is not any
"physical change" in you, it is merely a change in the way I observe you, or I
measure you (subtended angle). IOW: The only physical change here is just a
change in the RELATIONSHIP between you and me (viz. distance apart).

Similarly, "length contraction" in SR is just a change in the RELATIONSHIP
between the object and the observer (viz. relative velocity). There is no
"physical change" in either object or observer, just a change in the way the
observer observes or measures the object. Ditto for "time dilation".

But don't think this is "mere appearance" -- in the analogy there are real
physical consequences, such as my being able to see you through a smaller
aperture. For "time dilation" it means we can construct pion beamlines longer
than a few meters. For "length contraction" it means pointlike particle
interactions obey Bjorken scaling, at least approximately. These consequences
are all very well measured (just two of the myriad reasons why SR is solidly
accepted by physicists).


For the pole and barn "paradox", stopping the pole would release more energy
than an atomic bomb. The question "does the pole expand when it is stopped in
the barn?" is unanswerable, as it depends on the details of the stopping
mechanism and how the released kinetic energy is dissipated; moreover, no
recognizable "pole" could possibly remain.

But we do know this: the interatomic bonds between atoms
in the pole operate to maintain their normal interatomic
distance in their rest frame. So if one stops the pole in
such a way that these bonds are never overstressed beyond
their breaking point, the pole will have its normal proper
length. That is, as it slows to rest in an inertial frame
it will be measured to expand by an observer using that
frame (but as I keep stressing, to the pole itself no
"change" occurs). Such a "gentle" deceleration would take
zillions of kilometers for a pole moving with an appreciable
fraction of c.


Tom Roberts

Alter Gnostic

unread,
Jun 3, 2013, 12:11:38 PM6/3/13
to
On Monday, June 3, 2013 12:47:37 PM UTC-3, tjrob137 wrote:
> On 5/31/13 5/31/13 - 1:01 PM, altergnostic wrote:
>
> > [... length contraction ...]
>
> > By real changes in physical processes i mean effects like boiling water.
>
>
>
> Analogy: When you walk away from me, you APPEAR to get smaller. This is not any
>
> "physical change" in you, it is merely a change in the way I observe you, or I
>
> measure you (subtended angle). IOW: The only physical change here is just a
>
> change in the RELATIONSHIP between you and me (viz. distance apart).
>

Precisely.

>
>
> Similarly, "length contraction" in SR is just a change in the RELATIONSHIP
>
> between the object and the observer (viz. relative velocity). There is no
>
> "physical change" in either object or observer, just a change in the way the
>
> observer observes or measures the object. Ditto for "time dilation".
>

Indeed.

>
>
> But don't think this is "mere appearance" -- in the analogy there are real
>
> physical consequences, such as my being able to see you through a smaller
>
> aperture.

This isn't a real physical consequence, it is a real apparent consequence. Remember what I mean by "physical" here - these effects can't change physical processes, like internal clocks, generate heat (i.e. length contraction can't boil contracted water due to pressure), etc. Seeing someone far away through a smaller aperture doesn't mean the man fits in the aperture - he isn't squeezed by vanishing points.

> For "time dilation" it means we can construct pion beamlines longer
>
> than a few meters. For "length contraction" it means pointlike particle
>
> interactions obey Bjorken scaling, at least approximately. These consequences
>
> are all very well measured (just two of the myriad reasons why SR is solidly
>
> accepted by physicists).
>
>

So the question would be if these are truly physical changes or apparent changes, in the sense I have presented. If the pion beam is intrinsically longer (i.e. contains more pions - if that's even applicable - or contains more energy or whatever) or if it is apparently longer (i.e. the pion is not affected in any way and can't affect anything it interacts with in any different manner in comparison to non-dilated beams). For length contraction, I don't even understand how point-like particles can be contracted (although I get how it's surroundings would) nor I know what is Bjorken scaling - i'll look it up! - But the question would be the same.



>
>
>
> For the pole and barn "paradox", stopping the pole would release more energy
>
> than an atomic bomb. The question "does the pole expand when it is stopped in
>
> the barn?" is unanswerable, as it depends on the details of the stopping
>
> mechanism and how the released kinetic energy is dissipated; moreover, no
>
> recognizable "pole" could possibly remain.

This is irrelevant. It is a theoretical question, and the pole can be moving quite slowly, all we'd need is astonishingly precise measurements (far far far from what's practicable today), but since it is a theoretical question, it doesn't matter. The released energy could be of any magnitude we desire in this thought problem, and the contracted length can be in the planck scale range, if we like. Assume such change is measurable, assume the lowest conceivable velocity that would yield valid relativistic effects (viable in real-life setups or not).

In other words, this is a dodge.

>
>
>
> But we do know this: the interatomic bonds between atoms
>
> in the pole operate to maintain their normal interatomic
>
> distance in their rest frame. So if one stops the pole in
>
> such a way that these bonds are never overstressed beyond
>
> their breaking point, the pole will have its normal proper
>
> length. That is, as it slows to rest in an inertial frame
>
> it will be measured to expand by an observer using that
>
> frame (but as I keep stressing, to the pole itself no
>
> "change" occurs). Such a "gentle" deceleration would take
>
> zillions of kilometers for a pole moving with an appreciable
>
> fraction of c.
>
>
>

Sorry, but this sounds like misdirection, Tom. Again, this isn't a practicable thought problem. If we go down these lines, we'll end up arguing that this experiment is not humanly feasible and therefore can't be either validated or falsified. We could just as well state that a real macro rod can't be accelerated up to relativistic speeds, rendering the question is unanswerable. Is that what you're going for?

>
>
> Tom Roberts

Tom Roberts

unread,
Jun 5, 2013, 8:39:18 PM6/5/13
to
On 6/3/13 6/3/13 11:11 AM, Alter Gnostic wrote:
> On Monday, June 3, 2013 12:47:37 PM UTC-3, tjrob137 wrote:
>> On 5/31/13 5/31/13 - 1:01 PM, altergnostic wrote:
>> [...]
>> But don't think this is "mere appearance" -- in the analogy there are real
>> physical consequences, such as my being able to see you through a smaller
>> aperture.
>
> This isn't a real physical consequence, it is a real apparent consequence.

Physically using a smaller aperture sure looks "physical" to me.


> Remember what I mean by "physical" here - these effects can't change physical
> processes, like internal clocks, generate heat (i.e. length contraction can't
> boil contracted water due to pressure), etc. Seeing someone far away through
> a smaller aperture doesn't mean the man fits in the aperture - he isn't
> squeezed by vanishing points.

Sure. But if you insist on using a private language like that, count me out.


>> For "time dilation" it means we can construct pion beamlines longer
>> than a few meters. [...]

Go LOOK at the pion beamlines at Fermilab or CERN. They are as physical as
anything else. And without "time dilation" they would be impossible.


>> For the pole and barn "paradox", stopping the pole would release more
>> energy than an atomic bomb. [...]
> This is irrelevant. It is a theoretical question,[...[]
> In other words, this is a dodge.

Which I addressed in the very next paragraph. But first, I had to dismiss the
physical situation under discussion.


>> But we do know this: the interatomic bonds between atoms
>> in the pole operate to maintain their normal interatomic
>> distance in their rest frame. So if one stops the pole in
>> such a way that these bonds are never overstressed beyond
>> their breaking point, the pole will have its normal proper
>> length. That is, as it slows to rest in an inertial frame
>> it will be measured to expand by an observer using that
>> frame [...]
>
> Sorry, but this sounds like misdirection,

Then you need to read it more carefully. It directly and cogently addresses your
issue.

IOW: if you stop the pole in such a way that you don't damage it, and if you
have sufficient measurement resolution, then in your frame you will measure the
pole to expand as it stops.

And as I keep stressing, the pole itself does not "change" during
this procedure; it retains its normal proper length throughout.


Tom Roberts

Alter Gnostic

unread,
Jun 6, 2013, 1:38:40 AM6/6/13
to
On Wednesday, June 5, 2013 9:39:18 PM UTC-3, tjrob137 wrote:
> On 6/3/13 6/3/13 11:11 AM, Alter Gnostic wrote:
>
> > On Monday, June 3, 2013 12:47:37 PM UTC-3, tjrob137 wrote:
>
> >> On 5/31/13 5/31/13 - 1:01 PM, altergnostic wrote:
>
> >> [...]
>
> >> But don't think this is "mere appearance" -- in the analogy there are real
>
> >> physical consequences, such as my being able to see you through a smaller
>
> >> aperture.
>
> >
>
> > This isn't a real physical consequence, it is a real apparent consequence.
>
>
>
> Physically using a smaller aperture sure looks "physical" to me.
>
>
>
>
>
> > Remember what I mean by "physical" here - these effects can't change physical
>
> > processes, like internal clocks, generate heat (i.e. length contraction can't
>
> > boil contracted water due to pressure), etc. Seeing someone far away through
>
> > a smaller aperture doesn't mean the man fits in the aperture - he isn't
>
> > squeezed by vanishing points.
>
>
>
> Sure. But if you insist on using a private language like that, count me out.
>

I am unaware of a better way to put it... how would you express such notion?

>
>
>
>
> >> For "time dilation" it means we can construct pion beamlines longer
>
> >> than a few meters. [...]
>
>
>
> Go LOOK at the pion beamlines at Fermilab or CERN. They are as physical as
>
> anything else. And without "time dilation" they would be impossible.
>

I'm pretty sure the people at cern can't LOOK at the pions themselves either, I bet they can LOOK at a bunch of readings and mathematically interpret them as long pion beams though, using the time dilation equations.

>
>
>
>
> >> For the pole and barn "paradox", stopping the pole would release more
>
> >> energy than an atomic bomb. [...]
>
> > This is irrelevant. It is a theoretical question,[...[]
>
> > In other words, this is a dodge.
>
>
>
> Which I addressed in the very next paragraph. But first, I had to dismiss the
>
> physical situation under discussion.
>
>
>
>
>
> >> But we do know this: the interatomic bonds between atoms
>
> >> in the pole operate to maintain their normal interatomic
>
> >> distance in their rest frame. So if one stops the pole in
>
> >> such a way that these bonds are never overstressed beyond
>
> >> their breaking point, the pole will have its normal proper
>
> >> length. That is, as it slows to rest in an inertial frame
>
> >> it will be measured to expand by an observer using that
>
> >> frame [...]
>
> >
>
> > Sorry, but this sounds like misdirection,
>
>
>
> Then you need to read it more carefully. It directly and cogently addresses your
>
> issue.
>
>
>
> IOW: if you stop the pole in such a way that you don't damage it, and if you
>
> have sufficient measurement resolution, then in your frame you will measure the
>
> pole to expand as it stops.

Yes, that's what I thought, and I said that to Vertical, but he dismissed it. If this stretching affects the atomic bonds, we are saying that (changes in) relativistic effects by themselves can generate energy and affect physical processes: the total energy transfer in the pole deceleration scenario is not accounted for without relativity, there is a relativistic factor that comes into play and which transfers energy itself, such as the pole expansion. Is this correct?

Tom Roberts

unread,
Jun 6, 2013, 11:17:57 AM6/6/13
to
On 6/6/13 6/6/13 - 12:38 AM, Alter Gnostic wrote:
> On Wednesday, June 5, 2013 9:39:18 PM UTC-3, tjrob137 wrote:
>> Go LOOK at the pion beamlines at Fermilab or CERN. They are as physical as
>> anything else. And without "time dilation" they would be impossible.
>
> I'm pretty sure the people at cern can't LOOK at the pions themselves either,
> I bet they can LOOK at a bunch of readings and mathematically interpret them
> as long pion beams though, using the time dilation equations.

Your outrageously anthropocentric view of the world is invalid. To understand
the things you see requires applying models of how physical processes operate.
Applying the same sort of analysis to instruments outside your body is no
different in principle.

And learn to read more accurately: I asked you to look at the BEAMLINES, not the
beams. The BEAMLINES are a physical consequence of "time dilation" being valid
for their beams, as without it they could never have been built.


>> IOW: if you stop the pole in such a way that you don't damage it, and if
>> you
>> have sufficient measurement resolution, then in your frame you will measure
>> the
>> pole to expand as it stops.
>
> If this stretching affects the atomic bonds,

YOU'RE NOT PAYING ATTENTION. To the pole itself, and to the atomic bonds it
contains, there is no "stretching". I have said this repeatedly, in this thread
and in other threads around here: "length contraction" and "time dilation" are
merely artifacts of the geometrical projections involved, and do not involve any
sort of "physical change" in the object itself.

Until you learn to read more accurately, and to remember what you
have read, don't expect me to respond.


Tom Roberts

Lord Androcles, Zeroth Earl of Medway

unread,
Jun 6, 2013, 11:58:52 AM6/6/13
to
"Tom Roberts" wrote in message news:DsOdnRTUXIe...@giganews.com...
=====================================================

Glenn Harrison

unread,
Jun 6, 2013, 2:28:52 PM6/6/13
to
Tom Roberts wrote:

> Go LOOK at the pion beamlines at Fermilab or CERN. They are as physical
> as anything else. And without "time dilation" they would be impossible.

I beg to differ. Wherever time dilation is allegedly involved, one may
just use a speed higher than the speed of light in stead of. Problem
solved.

Glenn Harrison

unread,
Jun 6, 2013, 2:32:54 PM6/6/13
to
Tom Roberts wrote:

> And learn to read more accurately: I asked you to look at the BEAMLINES,
> not the beams. The BEAMLINES are a physical consequence of "time
> dilation"
> being valid for their beams, as without it they could never have been
> built.

You don't get your own argument. Why should a picture of a beam serve as a
proof of unmeasurable TIME dilation. There are no clocks flying inside
that beam.

Is about TIME that should be DILATED, and you have NOT even a model for it.

Absolutely Vertical

unread,
Jun 6, 2013, 3:03:31 PM6/6/13
to
unfortunately, this is not the case. the problem, you see, is that you
can actually measure the time of flight of the particles in the
beamline. the beam is pulsed and so you can watch the pulse pass a
detector at x_a, clock it at time t_a, then watch the pulse pass a
detector at x_b, clock it at time t_b. then you know pretty damn surely
that the particle is not going faster than the speed limit, exactly the
same way that helicopters watch cars for speeding on the highway.

Absolutely Vertical

unread,
Jun 6, 2013, 3:04:37 PM6/6/13
to
On 6/6/2013 1:32 PM, Glenn Harrison wrote:
> Tom Roberts wrote:
>
>> And learn to read more accurately: I asked you to look at the BEAMLINES,
>> not the beams. The BEAMLINES are a physical consequence of "time
>> dilation"
>> being valid for their beams, as without it they could never have been
>> built.
>
> You don't get your own argument. Why should a picture of a beam serve as a
> proof of unmeasurable TIME dilation. There are no clocks flying inside
> that beam.

oh but there are. the pions have a finite lifetime, and when they go
'ding' when they decay, you have a measurement of how much time has gone by.

altergnostic

unread,
Jun 6, 2013, 3:07:07 PM6/6/13
to
Tom Roberts <tjrobe...@sbcglobal.net> wrote:
> On 6/6/13 6/6/13 - 12:38 AM, Alter Gnostic wrote:
>> On Wednesday, June 5, 2013 9:39:18 PM UTC-3, tjrob137 wrote:
>>> Go LOOK at the pion beamlines at Fermilab or CERN. They are as physical as
>>> anything else. And without "time dilation" they would be impossible.
>>
>> I'm pretty sure the people at cern can't LOOK at the pions themselves either,
>> I bet they can LOOK at a bunch of readings and mathematically interpret them
>> as long pion beams though, using the time dilation equations.
>
> Your outrageously anthropocentric view of the world is invalid. To
> understand the things you see requires applying models of how physical
> processes operate. Applying the same sort of analysis to instruments
> outside your body is no different in principle.

Agreed, as you put it, to *understand* things we need models - not to *see*
them. I don't have to *understand* "this looks bigger than that".

>
> And learn to read more accurately: I asked you to look at the BEAMLINES,
> not the beams. The BEAMLINES are a physical consequence of "time
> dilation" being valid for their beams, as without it they could never have been built.

Ok, that totally escaped me, my bad.

>
>
>>> IOW: if you stop the pole in such a way that you don't damage it, and if
>>> you
>>> have sufficient measurement resolution, then in your frame you will measure
>>> the
>>> pole to expand as it stops.
>>
>> If this stretching affects the atomic bonds,
>
> YOU'RE NOT PAYING ATTENTION. To the pole itself, and to the atomic bonds
> it contains, there is no "stretching". I have said this repeatedly, in
> this thread and in other threads around here: "length contraction" and
> "time dilation" are merely artifacts of the geometrical projections
> involved, and do not involve any sort of "physical change" in the object itself.
>
> Until you learn to read more accurately, and to remember what you
> have read, don't expect me to respond.

Feisty!
Did you read the discussion i had with vertical? The point is that the
moving pole fits inside the box, comes to a stop and then doesn't fit in
the box anymore, therefore *pushing against the walls* from the inside - it
expands. This is a very physical change with very physical effects.

I completely agree that LC and TD are not physical effects per se, and only
geometrical artifacts, but here we have a change in these geometrical
descriptions causing a real change in physical processes - a real change in
the objects themselves.

>
>
> Tom Roberts

Glenn Harrison

unread,
Jun 6, 2013, 3:40:54 PM6/6/13
to
Absolutely Vertical wrote:

>> You don't get your own argument. Why should a picture of a beam serve
>> as a
>> proof of unmeasurable TIME dilation. There are no clocks flying inside
>> that beam.
>
> oh but there are. the pions have a finite lifetime, and when they go
> 'ding' when they decay, you have a measurement of how much time has gone
> by.

There are no models available telling that a pion or other particle must
have a finite and CONSTANT lifetime. A higher speed than the speed the
light is also a AVAILABLE solution to the problem. You don't get it as
well.

Glenn Harrison

unread,
Jun 6, 2013, 3:44:22 PM6/6/13
to
Absolutely Vertical wrote:

[snip crap]

> then you know pretty damn surely that the particle is not
> going faster than the speed limit, exactly the same way that helicopters
> watch cars for speeding on the highway.

No, you cannot tell anything about a particle at quantum level. There are
no clocks transported, nor MODELS telling exactly that. You don't get it.

Absolutely Vertical

unread,
Jun 6, 2013, 4:08:44 PM6/6/13
to
On 6/6/2013 2:07 PM, altergnostic wrote:
> Feisty!
> Did you read the discussion i had with vertical? The point is that the
> moving pole fits inside the box, comes to a stop and then doesn't fit in
> the box anymore, therefore*pushing against the walls* from the inside - it
> expands. This is a very physical change with very physical effects.

please be sure you're talking about the same circumstances with tom that
you did with me. in our conversation, we were talking about closing
_both_ apertures in the box, and moreover in our case the stopping force
was applied at only one end. in our case, there is no chance for the
pole to expand in a relaxed state, because the other wall of the box
prevents that.

what tom was referring to was a case where you applied a stopping force
such that the pole was not destroyed and for which there was no
constraint against the rod that would prevent it from expanding in a
relaxed state.

Absolutely Vertical

unread,
Jun 6, 2013, 4:13:43 PM6/6/13
to
well, actually, there is a model that says that pions have a specific
lifetime. it's called the standard model of particle interactions, and
the lifetime is completely determined by the rate the pion interacts via
the strong, weak, and electromagnetic interactions, and by the masses,
spins, parities and so forth of the final states allowed by those
interactions. you can _calculate_ the lifetime of a pion.

now, one can suppose there _might_ be a model where, by virtue of being
accelerated, a pion is affected dynamically (that is, the strength of
its interactions are changed) so that it lives longer. to date, no one
has come up with a successful model with those specific and quantitative
predictions. you are free to try.

Absolutely Vertical

unread,
Jun 6, 2013, 4:19:21 PM6/6/13
to
i'm not talking about something 'at quantum level' where i gather you
think everything is a big freakin' mystery. i'm talking about watching a
pulse of a tenth of a microcoulomb or so traveling a quarter mile down
an evacuated tube and hitting two detectors 1.3 microseconds apart.
there is nothing complicated or mysterious about measuring the
propagation speed of a charged pulse like that. any high school kid with
a long cable and an oscilloscope can do that.
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