Why is there more than one explanation for the Twin Paradox

[gehan.am...@gmail.com]

The Twin Paradox is predicted by Relativity theory. The event never took place in real life, it is purely hypothetical.

It seems strange that an effect predicted by a theory should need several different explanations, involving SRT, GRT, or a combination of both.

These explanations all cannot be true as they involve different effects:

Wikipedia:

Twin paradox
From Wikipedia, the free encyclopedia


In physics, the twin paradox is a thought experiment in special relativity involving identical twins, one of whom makes a journey into space in a high-speed rocket and returns home to find that the twin who remained on Earth has aged more. This result appears puzzling because each twin sees the other twin as moving, and so, according to an incorrect[1][2] and naive[3][4] application of time dilation and the principle of relativity, each should paradoxically find the other to have aged less. However, this scenario can be resolved within the standard framework of special relativity: the travelling twin's trajectory involves two different inertial frames, one for the outbound journey and one for the inbound journey, and so there is no symmetry between the spacetime paths of the twins. Therefore, the twin paradox is not a paradox in the sense of a logical contradiction.

Starting with Paul Langevin in 1911, there have been various explanations of this paradox. These explanations "can be grouped into those that focus on the effect of different standards of simultaneity in different frames, and those that designate the acceleration [experienced by the travelling twin] as the main reason...".[5] Max von Laue argued in 1913 that since the traveling twin must be in two separate inertial frames, one on the way out and another on the way back, this frame switch is the reason for the aging difference, not the acceleration per se.[6] Explanations put forth by Albert Einstein and Max Born invoked gravitational time dilation to explain the aging as a direct effect of acceleration.[7] General relativity is not necessary to explain the twin paradox; special relativity alone can explain the phenomenon.[8][9][10][11][12]

[Dono,]

On Wednesday, August 2, 2017 at 3:11:46 AM UTC-7, gehan.am...@gmail.com wrote:
> The event never took place in real life, it is purely hypothetical.
>

False. You are the same imbecile you have always been.

> It seems strange that an effect predicted by a theory should need several different explanations, involving SRT, GRT, or a combination of both.
>

That seems starnge because you are still the same crackpot you've always been.

> These explanations all cannot be true as they involve different effects:
>

Actually, they are.

[rotchm]

On Wednesday, August 2, 2017 at 6:11:46 AM UTC-4, gehan.am...@gmail.com wrote:
> The Twin Paradox is predicted by Relativity theory. The event
> never took place in real life, it is purely hypothetical.

It has took place in real life. That is similar/equivalent setups have been done (we did not actually use human twin if thats what you meant!).

> It seems strange that an effect predicted by a theory should need
> several different explanations, involving SRT, GRT, or a
> combination of both.

It does not need several walkthroughs, just one. But like
finding the answer to 1+2+3+...+100, there are many different approaches.

Also note that there are many different setups of the TP: Some involve accelerations, some do not. Some use triplets, some do not.

Also note that some solutions are sloppy (and even wrong!) & use ambiguous words.


<snipped bcause its too long to read>.

[Jeèným Ludnými]

Dne 28.7.2017 v 12:11 gehan.ameresekere napsal(a):

> The Twin Paradox is predicted by Relativity theory. The event never took
> place in real life, it is purely hypothetical.

Apparently not.

> In physics, the twin paradox is a thought experiment in special
> relativity involving identical twins,

"identical twins"?? This discussion is over.

[gehan.am...@gmail.com]

On Wednesday, August 2, 2017 at 7:15:27 PM UTC+5:30, rotchm wrote:
...

>
> Also note that some solutions are sloppy (and even wrong!) & use ambiguous words.
>
>

I am beginning to realize that there are better descriptions of the twin paradox and worser ones. I have been needlessly misled, hope to clear that up here.

So there are explanations involving SRT, GRT, and 'geometry'. Which theory resulted in the prediction of the twin paradox in the first place, is it not SRT only?

[gehan.am...@gmail.com]

That's Wikipedia's' definition ...

[rotchm]

On Thursday, August 3, 2017 at 3:01:25 AM UTC-4, gehan.am...@gmail.com

> I am beginning to realize that there are better descriptions of the
> twin paradox and worser ones. I have been needlessly misled, hope to
> clear that up here.
>
> So there are explanations involving SRT, GRT, and 'geometry'. Which
> theory resulted in the prediction of the twin paradox in the first
> place, is it not SRT only?

SR takes good care of the TP if one neglects gravity & accelerations.
For instance, the triplet version. Now, if one want to analyse the classical version whereby the traveler needs to accelerate, then SR can still be used if we analyze the situation solely from the POV of the home twin (since he is the only one that remains inertial). The conclusion will remain: traveler will return younger than the home twin. Many books that analyze this brush off too quickly the analysis and are very sloppy (like, many claim that we can just make the accelerations brief so they dont affect the total time; well, that reasoning is totally wrong, until they actually show that that is the case; they need to prove their assertion, but they dont).

[Tom Roberts]

On 8/2/17 8/2/17 6:11 AM, gehan.am...@gmail.com wrote:
> The Twin Paradox is predicted by Relativity theory. The event never took
> place in real life, it is purely hypothetical.

This is not true -- the twin paradox has been implemented several times, with
results consistent with the predictions of SR. The best one is by Bailey et al
in http://math.ucr.edu/home/baez/physics/Relativity/SR/experiments.html

> It seems strange that an effect predicted by a theory should need several
> different explanations, involving SRT, GRT, or a combination of both.

It doesn't "need" several explanations, any one will do. It's just that there
are multiple ways of looking at it. Note that this is true of almost every
experiment one can imagine, and also every gedanken.

> These explanations all cannot be true as they involve different effects:

Sure they can. They involve different effects for different sets of assumptions
or different theoretical contexts.

Why is "up" up?
1) because that's what the word means
2) because gravity points down (away from "up")
3) because free objects fall down
4) because objects at rest on the surface of the earth feel an
upward force from that surface
5) because all timelike geodesics near the surface of the earth
are accelerated down
These are five different explanations for a single question --
they involve different contexts. All five are obviously true.
> [... too complicated to bother with]

Tom Roberts

[Dono,]

On Thursday, August 3, 2017 at 5:58:46 AM UTC-7, rotchm wrote:
> On Thursday, August 3, 2017 at 3:01:25 AM UTC-4, gehan.am...@gmail.com
> > I am beginning to realize that there are better descriptions of the
> > twin paradox and worser ones. I have been needlessly misled, hope to
> > clear that up here.
> >
> > So there are explanations involving SRT, GRT, and 'geometry'. Which
> > theory resulted in the prediction of the twin paradox in the first
> > place, is it not SRT only?
>
> SR takes good care of the TP if one neglects gravity & accelerations.

False. SR handles acceleration just fine. You need to stop pretending you know what you are talking about. You don't.

> For instance, the triplet version. Now, if one want to analyse the classical version whereby the traveler needs to accelerate, then SR can still be used if we analyze the situation solely from the POV of the home twin (since he is the only one that remains inertial).

False again, there is a very good paper that analyzes the problem from the POV of the accelerating twin using SR. You need to stop pretending you know what you are talking about. You don't.

[gehan.am...@gmail.com]

On Friday, August 4, 2017 at 8:05:50 AM UTC+5:30, tjrob137 wrote:

OK but not sure about the origins of the twin paradox - was it predicted by SRT in which case SRT must have an explanation within itself for the effect. That was what I meant. Of course one could have several explanations for an effect, for example muon decay delays.

[Tom Roberts]

On 8/4/17 8/4/17 1:44 AM, gehan.am...@gmail.com wrote:
> [I'm] not sure about the origins of the twin paradox - was it predicted by

> SRT in which case SRT must have an explanation within itself for the effect.

Yes, it was first described shortly after SR was published in 1905.

In SR, the elapsed proper time of a clock moving relative to an inertial frame
is give by
\integral dt/gamma(v)
where t is the time coordinate of the inertial frame, v is the clock's speed
relative to that frame (as a function of t), gamma(v)=1/sqrt(1-v^2/c^2), and the
integral is taken over the clock's trajectory.

Since the home twin is at rest in an inertial frame, and the traveling twin is
moving relative to it, this unequivocally predicts the traveling twin returns
younger (less elapsed proper time) than the home twin. Actual experiments have
confirmed this quantitative prediction with an accuracy of a few parts per million.

Attempts to describe the situation from the perspective of the
traveling twin are complicated. Here there be dragons. Doesn't
matter, as the comparisons of their clocks at separation and
reunion are unequivocal; the dragons are related to intermediate
points and what "now" means to the traveling twin.

Tom Roberts

[Dono,]

On Friday, August 4, 2017 at 6:47:15 AM UTC-7, tjrob137 wrote:
>
> Attempts to describe the situation from the perspective of the
> traveling twin are complicated. Here there be dragons. Doesn't
> matter, as the comparisons of their clocks at separation and
> reunion are unequivocal; the dragons are related to intermediate
> points and what "now" means to the traveling twin.
>
> Tom Roberts

There is a very good paper on the subject. There are no "dragons"

[Thomas 'PointedEars' Lahn]

Tom Roberts wrote:

> In SR, the elapsed proper time of a clock moving relative to an inertial
> frame is give by
> \integral dt/gamma(v)
> where t is the time coordinate of the inertial frame, v is the clock's
> speed relative to that frame (as a function of t),
> gamma(v)=1/sqrt(1-v^2/c^2), and the integral is taken over the clock's
> trajectory.

JFTR & JFYI: As v > 0 → gamma(v) > 1, that is nothing but a description of
*time dilation* (a *proper* scientific term that, in contrast to other
scientific terms, for unknown reasons you ridiculously liked to put in
double-quotes, as if it were not).

> Since the home twin is at rest in an inertial frame, and the traveling
> twin is moving relative to it, this unequivocally predicts the traveling
> twin returns younger (less elapsed proper time) than the home twin. Actual
> experiments have confirmed this quantitative prediction with an accuracy
> of a few parts per million.
>
> Attempts to describe the situation from the perspective of the

> traveling twin are complicated. Here there be dragons. […]

I do not think it is that complicated. For the traveling twin, dx' = 0
→ dx'∕dt' = v' = 0 → gamma(v') = 1, so they do not observe time dilation in
their frame, but only proper time; but dx' = dx/gamma(v) – length
contraction –, so they are not amazed at all that they travel less spatial
distance than the rest distance in less proper time.

The traveling twin can further explain that (despite what they may expect
from the symmetry of time dilation) the home twin is older when they meet
again, with the *relativity of simultaneity*: *by contrast* to the home
twin, the traveling twin changes from at least one inertial frame to at
least one other when turning around. Assuming for simplicity that they are
only changing from a first inertial frame to a second one when turning
around, a different set of events in the home twin’s frame are simultaneous
in the traveling twin’s second frame than in their first frame, and some
home twin’s events during that journey are not simultaneous with *any*
events in the traveling twin’s two frames (with multiple frames there is
full correspondance, but only during the turning). If the traveling twin
could observe the home twin’s clock, when turning around they would observe
that clock jumping *ahead* of their clock (with multiple frames, gradually)
when before it was *behind* their clock.

It basically also says so in the Wikipedia article that (IIRC) I already
referred to, among several textbooks, I am confident, and the lines of
simultaneity in the/a Minkowski diagram clearly show it.

--
PointedEars

Twitter: @PointedEars2
Please do not cc me. / Bitte keine Kopien per E-Mail.

[Otten Schneijders]

Thomas 'PointedEars' Lahn wrote:

> Tom Roberts wrote:
>
>> In SR, the elapsed proper time of a clock moving relative to an
>> inertial frame is give by \integral dt/gamma(v)
>> where t is the time coordinate of the inertial frame, v is the clock's
>> speed relative to that frame (as a function of t),
>> gamma(v)=1/sqrt(1-v^2/c^2), and the integral is taken over the clock's
>> trajectory.
>
> JFTR & JFYI: As v > 0 → gamma(v) > 1, that is nothing but a description
> of *time dilation* (a *proper* scientific term that, in contrast to
> other scientific terms, for unknown reasons you ridiculously liked to
> put in double-quotes, as if it were not).

That's must be for the imbeciles without a brain. Stfu stupid, you are not
allowed to have an opinion, much less to comment Science. Go away. You are
also a known liar.

[Tom Roberts]

On 8/4/17 8/4/17 - 6:22 PM, Thomas 'PointedEars' Lahn wrote:
> Tom Roberts wrote:

>> [...]

> *time dilation* (a *proper* scientific term that, in contrast to other
> scientific terms, for unknown reasons you ridiculously liked to put in
> double-quotes, as if it were not).

I put "time dilation" and "length contraction" in quotes because they are VERY
POOR names for the phenomena they refer to. That is, for "time dilation" time
does NOT actually dilate, and for "length contraction" lengths do NOT actually
contract -- those phrases refer to the clock or object in question, which in all
cases is UNAFFECTED. Both "time dilation" and "length contraction" are really
geometrical projections that affect how observers moving relative to an object
will MEASURE the object, and the phrases do not capture this fact at all -- at
face value they imply that the object itself is somehow changed, but it isn't.

MANY people who are not experts in physics get confused by these phrases,
including many around here.

I have said all this many times before.

Tom Roberts

[gehan.am...@gmail.com]

Thanks Tom, that makes it all the more clearer. This is all about a 'transformation' when describing events in a moving frame to time and space measures in our stationary frame, adjusting for the fact that speeds approaching that of light are not additive.

But that begs the question does it not, if it is not a illusion, a real time one at that?

[gehan.am...@gmail.com]

And again, why is GRT attempted to be used to solve a scenario that owes its existence to SRT? (Wikipedie Twin Paradox)

[rotchm]

On Wednesday, August 9, 2017 at 8:32:47 AM UTC-4, gehan.am...@gmail.com

> And again, why is GRT attempted to be used to solve a scenario that owes its existence to SRT? (Wikipedie Twin Paradox)

Depends on what TP scenario you are referring to.
In the usual TP, GR is not required (when you analyze from the home twin).
But you can use GR if you want. However, if you want to analyze the situation from the POV of the traveling twin (versions where he is non inertial), then GR is required. This is well explained in the wiki page.

[Odd Bodkin]

On 8/9/17 7:30 AM, gehan.am...@gmail.com wrote:
> But that begs the question does it not, if it is not a illusion, a real time one at that?

In the sense that it affects reproducible measurements that fully adhere
to the defining characteristics of that measurement, then it is real.

Be careful about asking metaphysical questions like "is it real" while
carrying hidden baggage about what that term means. Some people, for
example, assume that real properties are completely independent of the
observer. If this were true, then properties like velocity and kinetic
energy and electric field could not be considered real -- under THAT
assumption of what "real" means. But for physicists, kinetic energy and
electric field are assuredly real, and so the hidden assumption about
what "real" means has to fall by the wayside.

--
Odd Bodkin -- maker of fine toys, tools, tables

[Tom Roberts]

On 8/9/17 8/9/17 7:30 AM, gehan.am...@gmail.com wrote:
> [Tom Roberts wrote] "Both "time dilation" and "length contraction" are

> really geometrical projections that affect how observers moving relative to
> an object will MEASURE the object, and the phrases do not capture this fact
> at all -- at face value they imply that the object itself is somehow changed,
> but it isn't."
>
> Thanks Tom, that makes it all the more clearer. This is all about a
> 'transformation' when describing events in a moving frame to time and space
> measures in our stationary frame, adjusting for the fact that speeds
> approaching that of light are not additive.
>
> But that begs the question does it not, if it is not a illusion, a real time
> one at that?

Illusions are what stage magicians do, or what certain pictures do that exploit
subtleties in human vision processing. This is not that.

Geometrical projections can and do have real, physical consequences:
1. the geometrical projection of a ladder's length onto the width of a
doorway determines whether it can be carried through the doorway.
2. The geometrical projection of a pion's proper time onto the lab
frame determines how far it can travel in a beamline before decaying.

Etc.

Tom Roberts

[mlwo...@wp.pl]

W dniu środa, 9 sierpnia 2017 19:18:41 UTC+2 użytkownik tjrob137 napisał:

> Geometrical projections can and do have real, physical consequences:

Sure, they can toggle some switches in a mind of insane
halfbrain.

[Dono,]

On Wednesday, August 9, 2017 at 6:28:48 AM UTC-7, rotchm wrote:
> However, if you want to analyze the situation from the POV of the traveling twin (versions where he is non inertial), then GR is required.

No.GR is not required, you are repeating the same idiocy you posted before.

[Tom Roberts]

On 8/9/17 8/9/17 7:32 AM, gehan.am...@gmail.com wrote

> And again, why is GRT attempted to be used to solve a scenario that owes its
> existence to SRT? (Wikipedie Twin Paradox)

GR can be used, but is not essential. As often happens in physics, there are
multiple ways to look at the physical situation, and multiple theories one can
apply.

> "Max von Laue argued in 1913 that since the traveling twin must be in two
> separate inertial frames, one on the way out and another on the way back,
> this frame switch is the reason for the aging difference, not the
> acceleration per se.[6] Explanations put forth by Albert Einstein and Max
> Born invoked gravitational time dilation to explain the aging as a direct
> effect of acceleration.[7] General relativity is not necessary to explain the
> twin paradox; special relativity alone can explain the
> phenomenon.[8][9][10][11][12]"

SR can certainly explain the twin paradox, quantitatively. Including
instantaneous or finite accelerations. GR can be used as well, but in flat
spacetime it of course gives results identical to those of SR.

Acceleration most definitely is NOT the root cause:
1. Good clocks are unaffected by acceleration (as long as they are not
broken by it). Experiments show that the timekeeping mechanism
governing muon decay is not affected by a proper acceleration of
10^18 g (!).
2. The triplet paradox, in which there is no acceleration, gives the same
result as the twin paradox with instantaneous frame changes.
3. Using GR and orbits around a massive object it is possible to construct
a twin scenario in which both twins move inertially, but have different
elapsed proper times between meetings.
4. In flat spacetime and SR, using two clocks on the rims of two adjacent
rotating tables, it is possible to arrange that the clock experiencing
larger proper acceleration has either less or more elapsed proper time
between meetings.
5. The basic calculation is of the elapsed proper time over a (timelike)
path through spacetime. When calculated in flat spacetime using an
inertial frame, acceleration does not appear in the integral, but
speed does.

In the usual twin paradox, it is not possible for the traveling twin to return
without experiencing acceleration. But the only "use" of the acceleration is in
changing inertial frames.

Tom Roberts

[JanPB]

Although there is a difference between the two in the sense that the doorway
is a physical object while spacetime is an abstraction (this may change
in future theories but in current space and time are not substances).

So the bottom line is that in relativity we have a model and a means
of quantification (for the elapsed time differences, say) but we don't
have any _underlying_ model from which the elapsed time differences (and
the geometry) would _emerge_.

--
Jan

--
Jan

[Tom Roberts]

On 8/9/17 8/9/17 2:23 PM, JanPB wrote:
>> Geometrical projections can and do have real, physical consequences:
>> 1. the geometrical projection of a ladder's length onto the width of a
>> doorway determines whether it can be carried through the doorway.
>> 2. The geometrical projection of a pion's proper time onto the lab
>> frame determines how far it can travel in a beamline before decaying.
>
> Although there is a difference between the two in the sense that the doorway
> is a physical object while spacetime is an abstraction (this may change
> in future theories but in current space and time are not substances).

Geometrical projections are ALWAYS part of the model, not the world. The pion
beamline is a physical object, just like the doorway. Those moving pions "fit"
in the beamline just as the ladder "fits" through the doorway, IF AND ONLY IF
the geometrical projection is favorable. Of course the ladder/doorway is a
projection in space, while the pion/beamline is a projection in spaceTIME.

> So the bottom line is that in relativity we have a model and a means
> of quantification (for the elapsed time differences, say) but we don't
> have any _underlying_ model from which the elapsed time differences (and
> the geometry) would _emerge_.

Yes. The relationship between geometrical projections in the model and
physically fitting in the world demonstrates that the model is an excellent one.
But don't be fooled into thinking that therefore the geometry "corresponds" to
"something" in the world....

Tom Roberts

[mlwo...@wp.pl]

W dniu czwartek, 10 sierpnia 2017 03:07:33 UTC+2 użytkownik tjrob137 napisał:
> On 8/9/17 8/9/17 2:23 PM, JanPB wrote:
> >> Geometrical projections can and do have real, physical consequences:
> >> 1. the geometrical projection of a ladder's length onto the width of a
> >> doorway determines whether it can be carried through the doorway.
> >> 2. The geometrical projection of a pion's proper time onto the lab
> >> frame determines how far it can travel in a beamline before decaying.
> >
> > Although there is a difference between the two in the sense that the doorway
> > is a physical object while spacetime is an abstraction (this may change
> > in future theories but in current space and time are not substances).
>
> Geometrical projections are ALWAYS part of the model, not the world.

And though they are not a pat of the world, they can and do
have real, physical consequences: they can toggle some switches
in the brain of a fanatic idiot.

[gehan.am...@gmail.com]

Thank you and excellent, clear answer to a question (from my point of view).

[gehan.am...@gmail.com]

Does this apply to GPS satellites? This would mean that satellites in the same position have different synch values to make with the ground station. Of course GPS satellites are geostationary, but what if.

[gehan.am...@gmail.com]

Do explore a somewhat obtuse parallel example, consider the Doppler effect - it only occurs when there is relative motion between the source and receiver and it collapses, for example, when the source and receiver are brought next to each other and the receiver or source stops. No legacy effects like in the age difference of twins. So the Doppler effect is a real time effect with no artefacts or permanent effects.

Why is not the 'time dilation' or the relativistic transformation the same? Does time have something to do with it?

[mlwo...@wp.pl]

W dniu środa, 9 sierpnia 2017 15:28:48 UTC+2 użytkownik rotchm napisał:


> Depends on what TP scenario you are referring to.
> In the usual TP, GR is not required (when you analyze from the home twin).
> But you can use GR if you want. However, if you want to analyze the situation from the POV of the traveling twin (versions where he is non inertial), then GR is required. This is well explained in the wiki page.

And you should also remember, that from the POV of a twin walking a street, trees and buildings are running around him. A physicist said, so there is no doubt; a physicist is an obvious expert of POVs.

[Winfred Tucker]

I never understand you trees analogy, you are using it every places. Dr.
Rotchm is mostly fully consistent. Except that the twin paradox, which is
not a paradox, is all about pure SR, not GR.

[mlwo...@wp.pl]

W dniu czwartek, 10 sierpnia 2017 12:15:06 UTC+2 użytkownik Winfred Tucker napisał:
> mlwozniak wrote:
>
> > W dniu środa, 9 sierpnia 2017 15:28:48 UTC+2 użytkownik rotchm napisał:
> >> Depends on what TP scenario you are referring to.
> >> In the usual TP, GR is not required (when you analyze from the home
> >> twin).
> >> But you can use GR if you want. However, if you want to analyze the
> >> situation from the POV of the traveling twin (versions where he is non
> >> inertial), then GR is required. This is well explained in the wiki
> >> page.
> >
> > And you should also remember, that from the POV of a twin walking a
> > street, trees and buildings are running around him. A physicist said, so
> > there is no doubt; a physicist is an obvious expert of POVs.
>
> I never understand you trees analogy, you are using it every places.

I'm not surprised. And I don't have much hope
you'll understand the question below:
Somewhere, deep in the real world, are living some
real observers with some real points of view. Do
your tales have something in common with them?

> Dr.
> Rotchm is mostly fully consistent.

Even if he was it wouldn't mean much.

[Odd Bodkin]

When the two clocks in the twin puzzle join again, it is found that
their rates are identical. So in this way they are exactly the same as
the Doppler effect that goes away when the source and receiver come to
relative rest.

The difference in *accumulated* time in the twins case then must have
something to do with the paths that they took, considered in totality.
(And you're going to be frustrated looking for one defining
characteristic that marks the difference.) So in the case of Doppler,
you should be looking at some parameter that is different for the two
light sources that has to do with the different paths that the light
took -- say for example the total delivered energy.

I think where you are getting confused is in attempting to compare
apples to oranges in the two cases. Compare things that are physically
more like apples to apples, and you'll see that the analogy is actually
pretty close.

[rotchm]

They are the same. Put two clocks side by side with relative speed zero: they tick at the same rate. The thing is with clocks, they are counters; they keep track, log, and "add" their results. The Doppler effect does not do this (because its not meant to; it is interested only in the rate, and not in the cumulative effect.).

[mlwo...@wp.pl]

W dniu czwartek, 10 sierpnia 2017 15:40:30 UTC+2 użytkownik Odd Bodkin napisał:

> When the two clocks in the twin puzzle join again, it is found that
> their rates are identical.

Wrong, poor idiot, of course. It's not theory anymore,
we have GPS. The rates are not identical.

[Tom Roberts]

No. Of course not -- GPS satellites never meet, which is a key feature of any
twin scenario.

> GPS satellites are geostationary

No, they aren't. They have an orbital period ~ 12 hours, and are much lower than
a geostationary orbit (but much higher than the ISS, Hubble, and other low-earth
orbit satellites).

Tom Roberts

[JanPB]

You are mixing two different concepts: the mundane appearances and
quantities calculated from coordinate systems.

--
Jan

[mlwo...@wp.pl]

And you're a queen of England, poor idiot.

[JanPB]

This is just gobbledygook. So you have no answer.

--
Jan

[Odd Bodkin]

Well, look at you! You've been doing your drunken catcall thing for a long
time, claiming that the GPS and ground clocks ARE synchronized and showing
the same rate and that the Galilean transformation t'=t is therefore shown
to be correct.

Now in your drunken catcalling you say the opposite.

Which means you just like the drunken catcalling, regardless of what you're
actually saying.

Same to ya, loser! Pfblbfftpblt!!

[Winfred Tucker]

mlwozniak wrote:

>> I never understand you trees analogy, you are using it every places.
>
> I'm not surprised. And I don't have much hope you'll understand the
> question below:
> Somewhere, deep in the real world, are living some real observers with
> some real points of view. Do your tales have something in common with
> them?

I'm tootaly loopy in here, of course I don't understand. Exactly because
I'm not stupid. Would have been stupid, I would have a chance to
understand. Stupid people always understand more than the clever ones.

[mlwo...@wp.pl]

W dniu czwartek, 10 sierpnia 2017 23:20:30 UTC+2 użytkownik Odd Bodkin napisał:
> <mlwo...@wp.pl> wrote:
> > W dniu czwartek, 10 sierpnia 2017 15:40:30 UTC+2 użytkownik Odd Bodkin napisał:
> >
> >> When the two clocks in the twin puzzle join again, it is found that
> >> their rates are identical.
> >
> > Wrong, poor idiot, of course. It's not theory anymore,
> > we have GPS. The rates are not identical.
> >
> >
>
> Well, look at you! You've been doing your drunken catcall thing for a long
> time, claiming that the GPS and ground clocks ARE synchronized and showing
> the same rate

A lie, of course. I'm claiming they are synchronized and
have equal indications t'=t. Never said they have the same
rate. Oppositely - if they had, they would unsynchronize.

Read again what you wrote.

>> When the two clocks in the twin puzzle join again, it is found that
>> their rates are identical.

Now, take the clock from GPS satellite back to Earth. Will
you really find what you claimed, poor idiot?

[JanPB]

He really thinks he is making a valid point.

--
Jan

[gehan.am...@gmail.com]

So what says there a cumulative effect?

[rotchm]

On Friday, August 11, 2017 at 3:58:26 AM UTC-4, gehan.am...@gmail.com wrote:

> So what says there a cumulative effect?

You. A clock is a device meant to accumulate, to count the total. View it this way:

1.1.1.1.1.1.1....

The doppler effect measures the # of dots between two successive 1's.
A clock counts the # of dots from start to your chosen end.

Simple, no?

[kenseto]

Better explanation: the twin clocks accumulate different number of clock seconds between meetings because they are in different states of absolute motion. The cause of this difference is that the competition of a transition of the Cs 133 atom is depedent on the arrival of a specific packet of energy from the aether.....the higher is the absolute motion of the Cs clock the larger amount of absolute time is needed for the arrival of this energy and thus the slower is the accumulation of clock seconds.

[Dono,]

There is no "absolute motion". You are as cretin as Stephane Baune.

>The cause of this difference is that the competition of a transition of the Cs 133 atom is depedent on the arrival of a specific packet of energy from the aether.....

There is no "aether". You are as cretin as Stephane Baune.

> the higher is the absolute motion of the Cs clock the larger amount of absolute time

There is no "absolute time". You are as cretin as Stephane Baune.

[Tom Roberts]

On 8/11/17 2:58 AM, gehan.am...@gmail.com wrote:
> So what says there a cumulative effect?

The way they are calculated:

"Time dilation" is a differential effect which depends only on the relative
velocity between the clock in question and an inertial frame. It is a
measurement effect for the inertial frame, and changes instantaneously when that
relative velocity changes.

Path length is an integral effect which for elapsed proper time of a clock
moving relative to an inertial frame depends on the entire path, including the
relative velocity relative to the frame at each and every point along the path.

Path length (elapsed proper time) is cumulative, "time dilation" is not. The
usual twin paradox demonstrates the former, not the latter.

Tom Roberts

[Odd Bodkin]

That is not a better explanation. The path difference explanation is
actually better. Whether you understand it or not makes no difference in
whether it is better or not.

>
>> (And you're going to be frustrated looking for one defining
>> characteristic that marks the difference.) So in the case of Doppler,
>> you should be looking at some parameter that is different for the two
>> light sources that has to do with the different paths that the light
>> took -- say for example the total delivered energy.
>>
>> I think where you are getting confused is in attempting to compare
>> apples to oranges in the two cases. Compare things that are physically
>> more like apples to apples, and you'll see that the analogy is actually
>> pretty close.
>>
>> --
>> Odd Bodkin -- maker of fine toys, tools, tables

[Nicolaas Vroom]

On Monday, 7 August 2017 16:22:34 UTC+2, tjrob137 wrote:
> On 8/4/17 8/4/17 - 6:22 PM, Thomas 'PointedEars' Lahn wrote:
> > Tom Roberts wrote:
> >> [...]
> > *time dilation* (a *proper* scientific term that, in contrast to other
> > scientific terms, for unknown reasons you ridiculously liked to put in
> > double-quotes, as if it were not).
>
> I put "time dilation" and "length contraction" in quotes because they are
> VERY POOR names for the phenomena they refer to. That is, for "time dilation"
> time does NOT actually dilate, and for "length contraction" lengths do NOT
> actually contract -- those phrases refer to the clock or object in question,
> which in all cases is UNAFFECTED.
> Both "time dilation" and "length contraction" are really geometrical
> projections that affect how observers moving relative to an object
> will MEASURE the object, and the phrases do not capture this fact at all
> -- at face value they imply that the object itself is somehow changed,
> but it isn't.

Is the concept geometrical projections equivalent with something mathematical?

Does this also indicate that both "time dilation" and "length contraction"
are not something physical? In the sense that when you heat an iron rod its
length becomes longer?

But what about a moving clock i.e. when two clocks are moved along
different path and when they meet the number of ticks is different?

Nicolaas Vroom

[mlwo...@wp.pl]

W dniu piątek, 11 sierpnia 2017 20:30:32 UTC+2 użytkownik Odd Bodkin napisał:


> > Better explanation: the twin clocks accumulate different number of clock seconds between meetings because they are in different states of absolute motion. The cause of this difference is that the competition of a transition of the Cs 133 atom is depedent on the arrival of a specific packet of energy from the aether.....the higher is the absolute motion of the Cs clock the larger amount of absolute time is needed for the arrival of this energy and thus the slower is the accumulation of clock seconds.
>
> That is not a better explanation. The path difference explanation is
> actually better.

And you know what is good and better, because
you make toys and tables.

[kenseto]

It certainly is a better explanation. It tells you exactly which clock is running slower (accumulating clock seconds at a slower rate. Your explanation don’t know which path gives you the slower rate clock.....so you asserted wrongly that A sees B running slower and B sees A runs slow and that gives you the false claim of reciprocity.

[The Starmaker]

But the question is...When did the number of ticks become different? At what time did the number of ticks become different?


1) right away

2) a little while later

3) a week later

4) sometimes

5) all the time

6) the first tick



I gotta get into my car and go varrrooooooooooooommmm.

[Odd Bodkin]

No, it's better because it makes accurate predictions of measurements that
had not been made previously, which Ken's stuff doesn't do. That is the
test of goodness in science. You have an entirely different view of what's
good, but that's you and has no bearing on science. And you have stated
that you don't care what's important to science, which is your right, not
that anyone else here cares what you think. Just makes people why you're
here, like the drunk at the baseball game.

[Odd Bodkin]

Oh that's bullshit, Ken. The one that has the bent worldline is the one
that has the less elapsed time, every time. You really know NOTHING about
relativity? Moreover, relativity will tell you HOW MUCH less elapsed time
will be there BEFORE the trip is taken. Yours cannot. Yours cannot PREDICT
based on the planned path.

.....so you asserted wrongly that A sees B running slower and B sees A runs
slow and that gives you the false claim of reciprocity.
>>
>>>
>>>> (And you're going to be frustrated looking for one defining
>>>> characteristic that marks the difference.) So in the case of Doppler,
>>>> you should be looking at some parameter that is different for the two
>>>> light sources that has to do with the different paths that the light
>>>> took -- say for example the total delivered energy.
>>>>
>>>> I think where you are getting confused is in attempting to compare
>>>> apples to oranges in the two cases. Compare things that are physically
>>>> more like apples to apples, and you'll see that the analogy is actually
>>>> pretty close.
>>>>
>>>> --
>>>> Odd Bodkin -- maker of fine toys, tools, tables
>>
>>
>> --
>> Odd Bodkin -- maker of fine toys, tools, tables
>

[mlwo...@wp.pl]

W dniu niedziela, 13 sierpnia 2017 22:08:12 UTC+2 użytkownik Odd Bodkin napisał:
> <mlwo...@wp.pl> wrote:
> > W dniu piątek, 11 sierpnia 2017 20:30:32 UTC+2 użytkownik Odd Bodkin napisał:
> >
> >
> >>> Better explanation: the twin clocks accumulate different number of
> >>> clock seconds between meetings because they are in different states of
> >>> absolute motion. The cause of this difference is that the competition
> >>> of a transition of the Cs 133 atom is depedent on the arrival of a
> >>> specific packet of energy from the aether.....the higher is the
> >>> absolute motion of the Cs clock the larger amount of absolute time is
> >>> needed for the arrival of this energy and thus the slower is the
> >>> accumulation of clock seconds.
> >>
> >> That is not a better explanation. The path difference explanation is
> >> actually better.
> >
> > And you know what is good and better, because
> > you make toys and tables.
> >
> >
>
> No, it's better because it makes accurate predictions of measurements that
> had not been made previously, which Ken's stuff doesn't do.

Yeah, these measurements made by imagined twins in imagined
rockets are predicted just perfectly. GPS t'=t is a bit worse.

That is the
> test of goodness in science.

And you know about goodness in science!! And you know
what is important in it!!! You simply can't be wrong
about it, because you make toys and tables.

[Paparios]

El domingo, 13 de agosto de 2017, 11:23:15 (UTC-3), Nicolaas Vroom escribió:
> On Monday, 7 August 2017 16:22:34 UTC+2, tjrob137 wrote:
> > On 8/4/17 8/4/17 - 6:22 PM, Thomas 'PointedEars' Lahn wrote:
> > > Tom Roberts wrote:
> > >> [...]
> > > *time dilation* (a *proper* scientific term that, in contrast to other
> > > scientific terms, for unknown reasons you ridiculously liked to put in
> > > double-quotes, as if it were not).
> >
> > I put "time dilation" and "length contraction" in quotes because they are
> > VERY POOR names for the phenomena they refer to. That is, for "time dilation"
> > time does NOT actually dilate, and for "length contraction" lengths do NOT
> > actually contract -- those phrases refer to the clock or object in question,
> > which in all cases is UNAFFECTED.
> > Both "time dilation" and "length contraction" are really geometrical
> > projections that affect how observers moving relative to an object
> > will MEASURE the object, and the phrases do not capture this fact at all
> > -- at face value they imply that the object itself is somehow changed,
> > but it isn't.
>
> Is the concept geometrical projections equivalent with something mathematical?
>
> Does this also indicate that both "time dilation" and "length contraction"
> are not something physical? In the sense that when you heat an iron rod its
> length becomes longer?
>

It is a geometrical projection that has physical consequences.
Like if you try to pass a ladder through a door, the geometrical orientation of the ladder projects the ladder onto the door. If the projection is less than the door width, you can pass the ladder through the door.

[kenseto]

You are a lying sack of shit. All the IRT equation are converted from the LT equations. so what ever the LT can predict IRT math will give the same predictions. I am not going to waste time on you....you are a moron who is void of knowledge of real physics.

[rotchm]

On Sunday, August 13, 2017 at 7:25:42 PM UTC-4, kenseto wrote:
> On Sunday, August 13, 2017 at 4:09:59 PM UTC-4, Odd Bodkin wrote:
>
> You are a lying sack of shit.

Hey idiot ken, WATCH YOUR MOUTH. Odd never has thrown insults to you, so you owe him (and me) the same respect he gives to you.

> All the IRT equation are converted from the LT equations.

No they are not. What ever gave you that idea? Can you provide a link to support your claim?

[Odd Bodkin]

This you say but you cannot do one fucking calculated prediction with
EITHER relativity or your stuff. You just make the BALD AND UNSUPPORTABLE
ASSERTION that whatever relativity predicts, so does your stuff. NO PROOF
OF THAT FROM YOU, NOT ONE STICK OF IT. You are a shameless fraud full of
empty claims and no proof of anything.

What you HAVE proven is that you do not understand relativity when you
claim relativity cannot tell which clock will show less accumulated time,
when IT CAN and DOES. You do not know anything about relativity and YOU
KNOW YOU DON'T and you have chosen to lie about that instead.

> I am not going to waste time on you....you are a moron who is void of
> knowledge of real physics.
>
>
>> .....so you asserted wrongly that A sees B running slower and B sees A runs
>> slow and that gives you the false claim of reciprocity.
>>>>
>>>>>
>>>>>> (And you're going to be frustrated looking for one defining
>>>>>> characteristic that marks the difference.) So in the case of Doppler,
>>>>>> you should be looking at some parameter that is different for the two
>>>>>> light sources that has to do with the different paths that the light
>>>>>> took -- say for example the total delivered energy.
>>>>>>
>>>>>> I think where you are getting confused is in attempting to compare
>>>>>> apples to oranges in the two cases. Compare things that are physically
>>>>>> more like apples to apples, and you'll see that the analogy is actually
>>>>>> pretty close.
>>>>>>
>>>>>> --
>>>>>> Odd Bodkin -- maker of fine toys, tools, tables
>>>>
>>>>
>>>> --
>>>> Odd Bodkin -- maker of fine toys, tools, tables
>>>
>>
>>
>>
>> --
>> Odd Bodkin -- maker of fine toys, tools, tables
>

[kenseto]

I don’t see you do any calculations with SR (LT) math.

> You just make the BALD AND UNSUPPORTABLE
> ASSERTION that whatever relativity predicts, so does your stuff. NO PROOF
> OF THAT FROM YOU, NOT ONE STICK OF IT. You are a shameless fraud full of
> empty claims and no proof of anything.

You are a lying sack of shit. The proof of derivation of the IRT math is in my book.

>
> What you HAVE proven is that you do not understand relativity when you
> claim relativity cannot tell which clock will show less accumulated time,
> when IT CAN and DOES. You do not know anything about relativity and YOU
> KNOW YOU DON'T and you have chosen to lie about that instead.

SR is a fail theory.....why? Because it predicts the impossible reciprocity. IRT does not predict reciprocity.

[JanPB]

On Sunday, August 13, 2017 at 1:36:47 PM UTC-7, mlwo...@wp.pl wrote:
> W dniu niedziela, 13 sierpnia 2017 22:08:12 UTC+2 użytkownik Odd Bodkin napisał:
> > <mlwo...@wp.pl> wrote:
> > > W dniu piątek, 11 sierpnia 2017 20:30:32 UTC+2 użytkownik Odd Bodkin napisał:
> > >
> > >
> > >>> Better explanation: the twin clocks accumulate different number of
> > >>> clock seconds between meetings because they are in different states of
> > >>> absolute motion. The cause of this difference is that the competition
> > >>> of a transition of the Cs 133 atom is depedent on the arrival of a
> > >>> specific packet of energy from the aether.....the higher is the
> > >>> absolute motion of the Cs clock the larger amount of absolute time is
> > >>> needed for the arrival of this energy and thus the slower is the
> > >>> accumulation of clock seconds.
> > >>
> > >> That is not a better explanation. The path difference explanation is
> > >> actually better.
> > >
> > > And you know what is good and better, because
> > > you make toys and tables.
> > >
> > >
> >
> > No, it's better because it makes accurate predictions of measurements that
> > had not been made previously, which Ken's stuff doesn't do.
>
>
> Yeah, these measurements made by imagined twins in imagined
> rockets are predicted just perfectly. GPS t'=t is a bit worse.

Incorrect.

> That is the
> > test of goodness in science.
>
> And you know about goodness in science!!

Sure.

> And you know
> what is important in it!!!

Correct.

> You simply can't be wrong
> about it, because you make toys and tables.

No, not "can't be wrong", merely you are wrong and he is right in this case. What he does
in his life otherwise is irrelevant.

--
Jan

[Odd Bodkin]

Bullshit, Ken. And I've given you PAGE REFERENCES in books where the
calculations are done. You say you won't bother even looking at them. If
you don't look at them, they don't exist, right?

>
>> You just make the BALD AND UNSUPPORTABLE
>> ASSERTION that whatever relativity predicts, so does your stuff. NO PROOF
>> OF THAT FROM YOU, NOT ONE STICK OF IT. You are a shameless fraud full of
>> empty claims and no proof of anything.
>
> You are a lying sack of shit. The proof of derivation of the IRT math is in my book.

NOT ONE CALCULATED PREDICTION. Just an empty claim the results will be the
same. You imposter.

>
>>
>> What you HAVE proven is that you do not understand relativity when you
>> claim relativity cannot tell which clock will show less accumulated time,
>> when IT CAN and DOES. You do not know anything about relativity and YOU
>> KNOW YOU DON'T and you have chosen to lie about that instead.
>
> SR is a fail theory.....why? Because it predicts the impossible
> reciprocity. IRT does not predict reciprocity.
>
>
>

[mlwo...@wp.pl]

A queen of England said.

[gehan.am...@gmail.com]

Not only clocks but:

Fuel flow meters
Biological processes
Crystal growth
Nuclear reactors

So the number of dots differs depending on? Are there 'lost dots' ?
I guess the travelling twin loses some of this dots.

[mlwo...@wp.pl]

W dniu poniedziałek, 14 sierpnia 2017 08:25:16 UTC+2 użytkownik gehan.am...@gmail.com napisał:

> Not only clocks but:

Because they don't - check in GPS.

>
> Fuel flow meters
> Biological processes
> Crystal growth
> Nuclear reactors

Unfortunately:
- nobody has ever checked how biological processes flow in a near light speed rocket
- nobody has ever checked how crystals grow in a near light speed rocket
- nobody has ever checked what fuel flow metters show in a near light speed rocket
- nobody has ever checked how nuclear reactors work in a in a near light speed rocket
- and clocks in GPS indicate t'=t. With the precision of an acceptable error.

[gehan.am...@gmail.com]

Need to get up to speed on 'proper time'

"The essence of the Special Theory of Relativity (STR) is that it connects three distinct quantities to each other: space, time, and proper time. ‘Time’ is also called coordinate time or real time, to distinguish it from ‘proper time’. Proper time is also called clock time, or process time, and it is a measure of the amount of physical process that a system undergoes. For example, proper time for an ordinary mechanical clock is recorded by the number of rotations of the hands of the clock. Alternatively, we might take a gyroscope, or a freely spinning wheel, and measure the number of rotations in a given period. We could also take a chemical process with a natural rate, such as the burning of a candle, and measure the proportion of candle that is burnt over a given period."

http://www.iep.utm.edu/proper-t/

[gehan.am...@gmail.com]

"proper time" is the rate of processes taking place within an inertial frame of reference. This article explains much:

http://www.iep.utm.edu/proper-t/

It admits that if you are moving along with your clocks and fuel flow meters and crystals, the laws of physics hold.

"Time dilation" or the 'correction factor for translating measurements and times between two systems moving at a relatively large fraction of the speed of light' is, as pointed out.. how did tjrob put it:

""Time dilation" is a differential effect which depends only on the relative
velocity between the clock in question and an inertial frame. It is a
measurement effect for the inertial frame, and changes instantaneously when that relative velocity changes"

Could it be that the two effects have been confused, where "time dilation" is a measurement effect to which permanence and cumulative effects have been wrongly attributed.

Could it be..

[mlwo...@wp.pl]

W dniu poniedziałek, 14 sierpnia 2017 12:08:56 UTC+2 użytkownik gehan.am...@gmail.com napisał:
> On Monday, August 14, 2017 at 12:53:11 PM UTC+5:30, mlwo...@wp.pl wrote:
> > W dniu poniedziałek, 14 sierpnia 2017 08:25:16 UTC+2 użytkownik gehan.am...@gmail.com napisał:
> >
> > > Not only clocks but:
> >
> > Because they don't - check in GPS.
> >
> > >
> > > Fuel flow meters
> > > Biological processes
> > > Crystal growth
> > > Nuclear reactors
> >
> > Unfortunately:
> > - nobody has ever checked how biological processes flow in a near light speed rocket
> > - nobody has ever checked how crystals grow in a near light speed rocket
> > - nobody has ever checked what fuel flow metters show in a near light speed rocket
> > - nobody has ever checked how nuclear reactors work in a in a near light speed rocket
> > - and clocks in GPS indicate t'=t. With the precision of an acceptable error.
>
> "proper time" is the rate of processes taking place within an inertial frame of reference. This article explains much:

:)
And proper system is communism. It's explained here:
https://www.marxists.org/archive/lenin/works/cw/

"within an inertial frame of reference" sounds like
"nowhere" to me, BTW.

[Gary Harnagel]

And nobody has ever checked Wozzie-boy's mental problems ... of have they?
He certainly is dealing with autism (or not dealing with it because he is
ignoring it).

[gehan.am...@gmail.com]

No need to check, because they all happen as they always happen.

Unless you are speeding by in a rocket trying to measure your experiments which are in the other rocket, you need to make sure nothing gets lost in the translation.

[mlwo...@wp.pl]

W dniu poniedziałek, 14 sierpnia 2017 15:30:06 UTC+2 użytkownik gehan.am...@gmail.com napisał:
> On Monday, August 14, 2017 at 4:09:21 PM UTC+5:30, mlwo...@wp.pl wrote:
> > W dniu poniedziałek, 14 sierpnia 2017 12:08:56 UTC+2 użytkownik gehan.am...@gmail.com napisał:
> > > On Monday, August 14, 2017 at 12:53:11 PM UTC+5:30, mlwo...@wp.pl wrote:
> > > > W dniu poniedziałek, 14 sierpnia 2017 08:25:16 UTC+2 użytkownik gehan.am...@gmail.com napisał:
> > > >
> > > > > Not only clocks but:
> > > >
> > > > Because they don't - check in GPS.
> > > >
> > > > >
> > > > > Fuel flow meters
> > > > > Biological processes
> > > > > Crystal growth
> > > > > Nuclear reactors
> > > >
> > > > Unfortunately:
> > > > - nobody has ever checked how biological processes flow in a near light speed rocket
> > > > - nobody has ever checked how crystals grow in a near light speed rocket
> > > > - nobody has ever checked what fuel flow metters show in a near light speed rocket
> > > > - nobody has ever checked how nuclear reactors work in a in a near light speed rocket
> > > > - and clocks in GPS indicate t'=t. With the precision of an acceptable error.
> > >
> > > "proper time" is the rate of processes taking place within an inertial frame of reference. This article explains much:
> >
> > :)
> > And proper system is communism. It's explained here:
> > https://www.marxists.org/archive/lenin/works/cw/
> >
> > "within an inertial frame of reference" sounds like
> > "nowhere" to me, BTW.
>
> No need to check, because they all happen as they always happen.

That's right, things in near-light-speed rockets are as usual,
no doubt. there is no need to check, for sure. But, still,
nobody has ever checked them.

[Nicolaas Vroom]

I do not fully understand.
You can pass a ladder of 5 by 20 by 200 cm through a hole of 6 by 21 cm.
If you have a box of 20 * 20 by 200 cm you cannot pass that box through that
same hole,

> > But what about a moving clock i.e. when two clocks are moved along
> > different path and when they meet the number of ticks is different?

IMO that is something physical

> > Nicolaas Vroom

[Odd Bodkin]

On 8/13/17 6:46 PM, kenseto wrote:
> You are a lying sack of shit. The proof of derivation of the IRT math is in my book.

I'll point out, Ken, that you keep pointing people to your book to see
your claimed calculations.
When people point you to other books to see the calculations of
relativity, you say you wouldn't dream of doing that.

Hypocrisy much?

[Paparios]

El lunes, 14 de agosto de 2017, 10:53:58 (UTC-3), Nicolaas Vroom escribió:
> On Monday, 14 August 2017 00:05:42 UTC+2, Paparios wrote:
> > El domingo, 13 de agosto de 2017, 11:23:15 (UTC-3), Nicolaas Vroom escribió:
> > > On Monday, 7 August 2017 16:22:34 UTC+2, tjrob137 wrote:
> > > > I put "time dilation" and "length contraction" in quotes because they are
> > > > VERY POOR names for the phenomena they refer to. That is, for "time dilation"
> > > > time does NOT actually dilate, and for "length contraction" lengths do NOT
> > > > actually contract -- those phrases refer to the clock or object in question,
> > > > which in all cases is UNAFFECTED.
> > > > Both "time dilation" and "length contraction" are really geometrical
> > > > projections that affect how observers moving relative to an object
> > > > will MEASURE the object, and the phrases do not capture this fact at all
> > > > -- at face value they imply that the object itself is somehow changed,
> > > > but it isn't.
> > >
> > > Is the concept geometrical projections equivalent with something mathematical?
> > >
> > > Does this also indicate that both "time dilation" and "length contraction"
> > > are not something physical? In the sense that when you heat an iron rod its
> > > length becomes longer?
> > >
> >
> > It is a geometrical projection that has physical consequences.
> > Like if you try to pass a ladder through a door, the geometrical orientation
> > of the ladder projects the ladder onto the door. If the projection is less
> > than the door width, you can pass the ladder through the door.
>
> I do not fully understand.

Yes it figures. You should try any book on Geometry.

> You can pass a ladder of 5 by 20 by 200 cm through a hole of 6 by 21 cm.
> If you have a box of 20 * 20 by 200 cm you cannot pass that box through that
> same hole,
>

Take your 50x300cm ladder through a 70x200 cm door. The geometrical projection
of the ladder onto the door has to be less than 70x200cm to pass through. If
you take it horizontal, 200 > 70 means it will not pass. You rotate it so its
geometrical projection is 50x60cm and the ladder goes through without a problem.

That it means the ladder length changed from 300cm to 60cm? Of course not,
only its orientation in space did.

Similarly, the traveling twin clock rate does not change in its path through
spacetime, but its geometrical projection does.

[Nicolaas Vroom]

On Wednesday, 9 August 2017 21:04:42 UTC+2, tjrob137 wrote:
>
> SR can certainly explain the twin paradox, quantitatively. Including
> instantaneous or finite accelerations. GR can be used as well, but in flat
> spacetime it of course gives results identical to those of SR.
>
> Acceleration most definitely is NOT the root cause:

I do not understand this. (See bootom)
In any experiment where you want to test the behaviour of identical
clocks with different speeds (the initial condition considered being
that all the clocks are at rest) there are always accelerations involved
specific if the final condition is that all the clocks meet at the same
point.

> 1. Good clocks are unaffected by acceleration (as long as they are not
> broken by it). Experiments show that the timekeeping mechanism
> governing muon decay is not affected by a proper acceleration of
> 10^18 g (!).

The condition of the experiment should be such that after all the clocks
meet again they should all tick at the same rate.

> 2. The triplet paradox, in which there is no acceleration, gives the same
> result as the twin paradox with instantaneous frame changes.

In a real triplet experiment there are also accelerations involved, except
they are outside the direct scope(?) of the experiment.
The point of the experiment is that: the longer the duration of the full
experiment (with constant speeds) the larger the final difference between
the clocks (or the more the staying at home twin has aged)

> 5. The basic calculation is of the elapsed proper time over a (timelike)
> path through spacetime. When calculated in flat spacetime using an
> inertial frame, acceleration does not appear in the integral, but
> speed does.

If you want to do it accurate you have to take all the speeds into account involved (starting 'slowly' from zero to v and back at each dt) which
implies acceleration.

The root cause is that the physical behaviour of clocks is affected by speed.

> In the usual twin paradox, it is not possible for the traveling twin to
> return without experiencing acceleration.

What the travelling twin B experience IMO is of no importance also not if B
truelly ages. What is important the clock B uses on the trip.

Nicolaas Vroom

[rotchm]

On Wednesday, August 16, 2017 at 10:25:22 AM UTC-4, Nicolaas Vroom wrote:
> On Wednesday, 9 August 2017 21:04:42 UTC+2, tjrob137 wrote:

> > Acceleration most definitely is NOT the root cause:
>
> I do not understand this. (See bootom)
> In any experiment where you want to test the behaviour of identical
> clocks with different speeds (the initial condition considered being
> that all the clocks are at rest) there are always accelerations involved
> specific if the final condition is that all the clocks meet at the same
> point.

Yes, there is usually accelerations involved. But its not the "accelerations" per se that makes the discrepancy; its the (instantaneous) speed. And even that is not necessary; we only need to know its trajectory (path) (and hence we know its speed; no need of the acceleration). That is what we mean by "acceleration has no effect". Its like a subtle play on words, if you would like.

That said, some versions of the twin paradox (TP) have no accelerations (the triplet version) and yet there is time dilation (TD). So again we see that accelerations are not the "root cause".

> The condition of the experiment should be such that after all the clocks
> meet again they should all tick at the same rate.

Yes, and that's what we try to use/attain. If the returning clock no longer functions as its supposed too, we deem it "not a good clock" or "broken".

>
> > 2. The triplet paradox, in which there is no acceleration, gives the same
> > result as the twin paradox with instantaneous frame changes.
>
> In a real triplet experiment there are also accelerations involved,

No there arent.

> except
> they are outside the direct scope(?) of the experiment.

Perhaps, but its irrelevant what the scientist had for breakfast; its irrelevant what we do with the clock after the experiment is done. During the experiment (the scenario), there are no accelerations whatsoever.

> The point of the experiment is that: the longer the duration of the full
> experiment (with constant speeds) the larger the final difference between
> the clocks (or the more the staying at home twin has aged)

Yes, thats about it.

>
> > 5. The basic calculation is of the elapsed proper time over a (timelike)
> > path through spacetime. When calculated in flat spacetime using an
> > inertial frame, acceleration does not appear in the integral, but
> > speed does.
>
> If you want to do it accurate you have to take all the speeds into account involved (starting 'slowly' from zero to v and back at each dt) which
> implies acceleration.

Yes. And thats done in some literature too. But since its not that interesting and does not add to the understanding, we tend to jump over it.

> The root cause is that the physical behaviour of clocks is
> affected by speed.

Perhaps, or perhaps not. "causes" in physics are irrelevant.
We have a model, describe by formulas. The formulas predict the end results.
The gamma factor 1/√(1 - v²(t)) contains but the speed, not the acceleration and this suffices to find the elapsed time (change in value).

[Dono,]

On Wednesday, August 16, 2017 at 7:59:36 AM UTC-7, rotchm wrote:
>
> That said, some versions of the twin paradox (TP) have no accelerations (the triplet version) and yet there is time dilation (TD). So again we see that accelerations are not the "root cause".
>

The Twin paradox has nothing to do with Time Dilaton. Time Dilation does not intervene in the explanation of the Twin Paradox.

> > If you want to do it accurate you have to take all the speeds into account involved (starting 'slowly' from zero to v and back at each dt) which
> > implies acceleration.
>
> Yes. And thats done in some literature too. But since its not that interesting and does not add to the understanding, we tend to jump over it.
>

Actually, it does. Only reductionist imbeciles like Stephane Baune would claim such an idiocy.

[Paparios]

El miércoles, 16 de agosto de 2017, 11:25:22 (UTC-3), Nicolaas Vroom escribió:
> On Wednesday, 9 August 2017 21:04:42 UTC+2, tjrob137 wrote:
> >
> > SR can certainly explain the twin paradox, quantitatively. Including
> > instantaneous or finite accelerations. GR can be used as well, but in flat
> > spacetime it of course gives results identical to those of SR.
> >
> > Acceleration most definitely is NOT the root cause:
>
> I do not understand this. (See bootom)
> In any experiment where you want to test the behaviour of identical
> clocks with different speeds (the initial condition considered being
> that all the clocks are at rest) there are always accelerations involved
> specific if the final condition is that all the clocks meet at the same
> point.
>

What the experiments show is that atomic clocks (the type of clocks used in
scientific experiments) are not affected by acceleration. Tom even put the
number just below.

> > 1. Good clocks are unaffected by acceleration (as long as they are not
> > broken by it). Experiments show that the timekeeping mechanism
> > governing muon decay is not affected by a proper acceleration of
> > 10^18 g (!).
>
> The condition of the experiment should be such that after all the clocks
> meet again they should all tick at the same rate.
>

But they do, the reunited clocks are tested and sure enough they continue to

tick at the same rate.

> > 2. The triplet paradox, in which there is no acceleration, gives the same
> > result as the twin paradox with instantaneous frame changes.
>
> In a real triplet experiment there are also accelerations involved, except
> they are outside the direct scope(?) of the experiment.
> The point of the experiment is that: the longer the duration of the full
> experiment (with constant speeds) the larger the final difference between
> the clocks (or the more the staying at home twin has aged)
>

Again, accelerations do not affect the clock ticking.

> > 5. The basic calculation is of the elapsed proper time over a (timelike)
> > path through spacetime. When calculated in flat spacetime using an
> > inertial frame, acceleration does not appear in the integral, but
> > speed does.
>
> If you want to do it accurate you have to take all the speeds into account involved (starting 'slowly' from zero to v and back at each dt) which
> implies acceleration.
>

What? Are you unable to read above?

> The root cause is that the physical behaviour of clocks is affected by speed.
>

Total nonsense. If the atomic clock rate are not affected by acceleration, why would they be affected by speed?

> > In the usual twin paradox, it is not possible for the traveling twin to
> > return without experiencing acceleration.
>
> What the travelling twin B experience IMO is of no importance also not if B
> truelly ages. What is important the clock B uses on the trip.
>
> Nicolaas Vroom

Yeah right....
This is a waste of time...PLONK

[mlwo...@wp.pl]

W dniu czwartek, 17 sierpnia 2017 01:37:40 UTC+2 użytkownik Paparios napisał:

> But they do, the reunited clocks are tested and sure enough they continue to
> tick at the same rate.

Bullshit. Yake the clock from GPS back to Earth, poor idiot - the rate will
be different.

[gehan.am...@gmail.com]

On Monday, August 14, 2017 at 9:26:47 PM UTC+5:30, Paparios wrote:
> El lunes, 14 de agosto de 2017, 10:53:58 (UTC-3), Nicolaas Vroom escribió:
> > On Monday, 14 August 2017 00:05:42 UTC+2, Paparios wrote:
> > > El domingo, 13 de agosto de 2017, 11:23:15 (UTC-3), Nicolaas Vroom escribió:
> > > > On Monday, 7 August 2017 16:22:34 UTC+2, tjrob137 wrote:
> > > > > I put "time dilation" and "length contraction" in quotes because they are

> > > > > VERY POOR names for the phenomena they refer to. That is, for "time d.....

"Similarly, the traveling twin clock rate does not change in its path through
spacetime, but its geometrical projection does. "

Does the Pioneer spacecraft represent a travelling twin? In which case can we verify the twin paradox effect by using the signals from the Pioneer? This would sort of settle it.

Wikipedia

"Pioneer 10 crossed the orbit of Saturn in 1976 and the orbit of Uranus in 1979.[47] On June 13, 1983, the craft crossed the orbit of Neptune, the outermost planet, and so became the first human-made object to leave the proximity of the major planets of the Solar System. The mission came to an official end on March 31, 1997, when it had reached a distance of 67 AU from the Sun, though the spacecraft was still able to transmit coherent data after this date"

[Paparios]

El jueves, 17 de agosto de 2017, 7:05:14 (UTC-4), gehan.am...@gmail.com escribió:
> On Monday, August 14, 2017 at 9:26:47 PM UTC+5:30, Paparios wrote:
> > El lunes, 14 de agosto de 2017, 10:53:58 (UTC-3), Nicolaas Vroom escribió:
> > > On Monday, 14 August 2017 00:05:42 UTC+2, Paparios wrote:
> > > > El domingo, 13 de agosto de 2017, 11:23:15 (UTC-3), Nicolaas Vroom escribió:
> > > > > On Monday, 7 August 2017 16:22:34 UTC+2, tjrob137 wrote:
> > > > > > I put "time dilation" and "length contraction" in quotes because they are
> > > > > > VERY POOR names for the phenomena they refer to. That is, for "time d.....
>
>
>
> "Similarly, the traveling twin clock rate does not change in its path through
> spacetime, but its geometrical projection does. "
>
>
> Does the Pioneer spacecraft represent a travelling twin? In which case can we verify the twin paradox effect by using the signals from the Pioneer? This would sort of settle it.
>

Well, bring it back and check it here on Earth. That would be a travelling twin
scenario.

[kenseto]

But after it went through the door via orientation can it be contained in a 70x200x200 cm barn briefly with both barn doors close simultaneously? I think not.

[Paparios]

El viernes, 18 de agosto de 2017, 11:07:44 (UTC-3), kenseto escribió:
> On Monday, August 14, 2017 at 11:56:47 AM UTC-4, Paparios wrote:
> > El lunes, 14 de agosto de 2017, 10:53:58 (UTC-3), Nicolaas Vroom escribió:

> >
> > Take your 50x300cm ladder through a 70x200 cm door. The geometrical projection
> > of the ladder onto the door has to be less than 70x200cm to pass through. If
> > you take it horizontal, 200 > 70 means it will not pass. You rotate it so its
> > geometrical projection is 50x60cm and the ladder goes through without a problem.
>
> But after it went through the door via orientation can it be contained in a 70x200x200 cm barn briefly with both barn doors close simultaneously? I think not.
>

If you are referring to the pole and barn paradox, then the ladder has to be
traveling at v=0.8c, for example. At that speed, an observer in the barn will
see the ladder to be length contracted and, for sure, to be fully contained
inside the barn with its doors closed.
The situation for the observer with the ladder is different. For him the ladder
has the same length it had before moving, but it will pass through the barn
unharmed, since the doors for that observer do not close at the same time
(due to relativity of simultaneity)

[Nicolaas Vroom]

On Wednesday, 16 August 2017 16:59:36 UTC+2, rotchm wrote:
> On Wednesday, August 16, 2017 at 10:25:22 AM UTC-4, Nicolaas Vroom wrote:
>
> That said, some versions of the twin paradox (TP) have no accelerations
> (the triplet version) and yet there is time dilation (TD). So again we
> see that accelerations are not the "root cause".

Okay

> Yes, and that's what we try to use/attain. If the returning clock no
> longer functions as its supposed too, we deem it "not a good clock"
> or "broken".

Okay

> > except
> > they are outside the direct scope(?) of the experiment.
>
> Perhaps, but its irrelevant what the scientist had for breakfast;
> its irrelevant what we do with the clock after the experiment is
> done. During the experiment (the scenario), there are no accelerations
> whatsoever.

I agree with your final remark, but considering the experiment in total
there are accelerations involved.

> > The point of the experiment is that: the longer the duration of the full
> > experiment (with constant speeds) the larger the final difference between
> > the clocks (or the more the staying at home twin has aged)
>
> Yes, thats about it.

But important

> > If you want to do it accurate you have to take all the speeds into account
> > involved (starting 'slowly' from zero to v and back at each dt) which
> > implies acceleration.
>
> Yes. And thats done in some literature too. But since its not that interesting
> and does not add to the understanding, we tend to jump over it.

Okay. Interesting

> > The root cause is that the physical behaviour of clocks is
> > affected by speed.
>
> Perhaps, or perhaps not. "causes" in physics are irrelevant.

The causes in physics are the actual descriptions of the processes that
take place. It is a light which is reflected between two mirrors
at rest versus two mirrors which both have a speed v.
Generally speaking the path in the second case (moving) is longer
then the first case (at rest). This physical explains why there is a
difference between the two clocks.

> We have a model, describe by formulas. The formulas predict the end results.
> The gamma factor 1/√(1 - v²(t)) contains but the speed, not the acceleration
> and this suffices to find the elapsed time (change in value).

When you start with the physical model you can derive based on some
simple mathematics the gamma factor.
The final part is to test the gamma factor based on actual experiments.
When they agree all the steps leading to the final formula are correct.

Nicolaas Vroom

[Tom Roberts]

On 8/16/17 8/16/17 9:25 AM, Nicolaas Vroom wrote:
> On Wednesday, 9 August 2017 21:04:42 UTC+2, tjrob137 wrote:
>> SR can certainly explain the twin paradox, quantitatively. Including
>> instantaneous or finite accelerations. GR can be used as well, but in flat
>> spacetime it of course gives results identical to those of SR.
>>
>> Acceleration most definitely is NOT the root cause:
>
> I do not understand this. (See bootom)

Hmmmm. Note that muons experiencing 10^18 g as they go around a ring have the
same lifetime measured in the lab as muons that travel at the same speed along a
straight line with essentially no acceleration. So acceleration does not affect
the timekeeping mechanism of muon decay. GPS satellite clocks are likewise
unaffected by their acceleration, giving us confidence to apply the same idea to
all clocks: they are unaffected by acceleration. And that is how SR and GR model it.

> In any experiment where you want to test the behaviour of identical
> clocks with different speeds (the initial condition considered being
> that all the clocks are at rest) there are always accelerations involved
> specific if the final condition is that all the clocks meet at the same
> point.

No. You are assuming things which are not present.

>> 1. Good clocks are unaffected by acceleration (as long as they are not
>> broken by it). Experiments show that the timekeeping mechanism
>> governing muon decay is not affected by a proper acceleration of
>> 10^18 g (!).
>
> The condition of the experiment should be such that after all the clocks
> meet again they should all tick at the same rate.

Can't be done. Experiments are what they are, not what you WISH them to be.

>> 2. The triplet paradox, in which there is no acceleration, gives the same
>> result as the twin paradox with instantaneous frame changes.
>
> In a real triplet experiment there are also accelerations involved, except
> they are outside the direct scope(?) of the experiment.

Perhaps, but perhaps the triplets were each born in their inertial frame. In
this scenario there is no need for them to be born together. But that's
irrelevant -- activities before the experiment started don't matter.

> The point of the experiment is that: the longer the duration of the full
> experiment (with constant speeds) the larger the final difference between
> the clocks (or the more the staying at home twin has aged)

This is a GEDANKEN, not a real experiment. The gedanken certainly behaves that way.

>> 5. The basic calculation is of the elapsed proper time over a (timelike)
>> path through spacetime. When calculated in flat spacetime using an
>> inertial frame, acceleration does not appear in the integral, but
>> speed does.
>
> If you want to do it accurate you have to take all the speeds into account involved (starting 'slowly' from zero to v and back at each dt) which
> implies acceleration.

THIS calculation can handle arbitrary accelerations. But the accelerations do
not contribute to the result, only the resulting path and its speed (relative to
that inertial frame) contribute. That is, acceleration affects the path but not
the calculation itself, but the calculation depends on the path.

> The root cause is that the physical behaviour of clocks is affected by speed.

No! NOT AT ALL! Experiments show the opposite: speed does not affect the
physical behavior of clocks. It only affects how observers MEASURE them. That,
however, does not make it "imaginary", or "fictitious", or "illusory", because
it can have real physical consequences (such as pion beams 1 km long being useful).

If what you claim were true, Einstein's first postulate of SR
could not possibly be valid. But myriad experiments show that
SR is valid.

Tom Roberts

[mlwo...@wp.pl]

W dniu sobota, 19 sierpnia 2017 00:08:29 UTC+2 użytkownik tjrob137 napisał:

> No! NOT AT ALL! Experiments show the opposite: speed does not affect the
> physical behavior of clocks.

Your gedanken experiments only, poor idiot.
As for reality, clocks of GPS satellite coun second
with different numer of ticks than clocks on Earth.
As you've said, experiments are what they are, not

[gehan.am...@gmail.com]

Why does it need to be brought back? In this age of virtual reality why is physical presence necessary? Video transmissions would do, would they not?

Suppose the twins never physically meet but their spaceships are brought back and they see each other through video?

[Prokaryotic Caspase Homolog]

On Friday, August 18, 2017 at 5:08:29 PM UTC-5, tjrob137 wrote:

> Note that muons experiencing 10^18 g as they go around a ring have the
> same lifetime measured in the lab as muons that travel at the same speed along a
> straight line with essentially no acceleration. So acceleration does not affect
> the timekeeping mechanism of muon decay.

Acceleration should not have _no_effect_at_all_ on muon decay, merely
_unmeasurable_ effects. Are there any sorts of heuristic arguments that one
might apply to estimate what level of acceleration might significantly affect
muon decay?

By analogy, I was considering singly-ionized helium traveling around a ring.
Given Coulomb's law and the dimensions of the helium ion, I imagine that the
second electron should be stripped from the helium ion, leaving an alpha
particle, at accelerations above, say, 5e21 g or so.

Looking at a table of muon properties, I see nothing obvious that would allow
me to perform any sort of "Fermi-estimate" on what accelerations might begin to
have a significant effect on muon lifespan.

It seems fun to speculate, however.

[kenseto]

On Friday, August 18, 2017 at 11:04:21 AM UTC-4, Paparios wrote:
> El viernes, 18 de agosto de 2017, 11:07:44 (UTC-3), kenseto escribió:
> > On Monday, August 14, 2017 at 11:56:47 AM UTC-4, Paparios wrote:
> > > El lunes, 14 de agosto de 2017, 10:53:58 (UTC-3), Nicolaas Vroom escribió:
>
> > >
> > > Take your 50x300cm ladder through a 70x200 cm door. The geometrical projection
> > > of the ladder onto the door has to be less than 70x200cm to pass through. If
> > > you take it horizontal, 200 > 70 means it will not pass. You rotate it so its
> > > geometrical projection is 50x60cm and the ladder goes through without a problem.
> >
> > But after it went through the door via orientation can it be contained in a 70x200x200 cm barn briefly with both barn doors close simultaneously? I think not.
> >
>
> If you are referring to the pole and barn paradox, then the ladder has to be
> traveling at v=0.8c, for example. At that speed, an observer in the barn will
> see the ladder to be length contracted and, for sure, to be fully contained
> inside the barn with its doors closed.

So that means material contraction but your SR brothers (Bodkin and Tom) said that there is no material contraction. Do you agree

[kenseto]

On Saturday, August 19, 2017 at 11:34:34 AM UTC-4, kenseto wrote:
> On Friday, August 18, 2017 at 11:04:21 AM UTC-4, Paparios wrote:
> > El viernes, 18 de agosto de 2017, 11:07:44 (UTC-3), kenseto escribió:
> > > On Monday, August 14, 2017 at 11:56:47 AM UTC-4, Paparios wrote:
> > > > El lunes, 14 de agosto de 2017, 10:53:58 (UTC-3), Nicolaas Vroom escribió:
> >
> > > >
> > > > Take your 50x300cm ladder through a 70x200 cm door. The geometrical projection
> > > > of the ladder onto the door has to be less than 70x200cm to pass through. If
> > > > you take it horizontal, 200 > 70 means it will not pass. You rotate it so its
> > > > geometrical projection is 50x60cm and the ladder goes through without a problem.
> > >
> > > But after it went through the door via orientation can it be contained in a 70x200x200 cm barn briefly with both barn doors close simultaneously? I think not.
> > >
> >
> > If you are referring to the pole and barn paradox, then the ladder has to be
> > traveling at v=0.8c, for example. At that speed, an observer in the barn will
> > see the ladder to be length contracted and, for sure, to be fully contained
> > inside the barn with its doors closed.
>
> So that means material contraction but your SR brothers (Bodkin and Tom) said that there is no material >contraction. Do you agree

The computer sends out my post before I was ready.
So according to you, the pole is materially contracted but your SR brothers (Bodkin and Tom) said that there is no material contraction. Do you agree with Tom and Bodkin or do you believe that there was material contraction?

The third alternative is that the contraction is merely a geometric projection of the pole unto the barn frame and that this projection can be fit into the barn with both doors close simultaneously.... the material length of the pole cannot fit into the barn at anytime. This interpretation is similar to my interpretation. In my theory IRT, the barn observer predicts that the light-path length of the pole is foreshortened by a factor of 1/gamma and this foreshortened light-path length can fit into the barn at any time. This IRT prediction is based on the assumption that the light-path length of the same pole at rest in the barn is its material length.
A paper on IRT is available in the following link:
http://www.modelmechanics.org/2015irt.pdf
>

[Nicolaas Vroom]

On Thursday, 17 August 2017 01:37:40 UTC+2, Paparios wrote:

> El miércoles, 16 de agosto de 2017, 11:25:22 (UTC-3), Nicolaas Vroom wrote:
> > On Wednesday, 9 August 2017 21:04:42 UTC+2, tjrob137 wrote:
> > >
> > > SR can certainly explain the twin paradox, quantitatively. Including
> > > instantaneous or finite accelerations. GR can be used as well, but in
> > > flat spacetime it of course gives results identical to those of SR.
> > >
> > > Acceleration most definitely is NOT the root cause:
> >
> > I do not understand this. (See bootom)
> > In any experiment where you want to test the behaviour of identical
> > clocks with different speeds (the initial condition considered being
> > that all the clocks are at rest) there are always accelerations involved
> > specific if the final condition is that all the clocks meet at the same
> > point.
> >
>
> What the experiments show is that atomic clocks (the type of clocks used in
> scientific experiments) are not affected by acceleration. Tom even put the
> number just below.

I'am not writing here that they are affected by accelerations.
In any such experiments there are always different speeds involved which
indistinguishable implies that there are accelerations involved.

Read page 167 of the book GRAVITATION
"Exercise 6.3 Twin Paradox
(a) show that of all timelike world lines connecting two events A and B the
one with the longest lapse of proper time is the unaccelerated one (hint:
perform the calculation in the inertial frame of the unaccelerated world line)
(b) One twin chooses to move from A to B along the unaccelerated world line.
Show that the other twin, by appropriate choice of accelerations can get from
A to B in arbitrary small proper time"
Also see page 315.

> But they do, the reunited clocks are tested and sure enough they continue to
> tick at the same rate.

That is also my understanding
The point is that the final readings are different, which implies that
something must have happened inbetween.

> > > 2. The triplet paradox,

> > The point of the experiment is that: the longer the duration of the full
> > experiment (with constant speeds) the larger the final difference between
> > the clocks (or the more the staying at home twin has aged)
>
> Again, accelerations do not affect the clock ticking.

But something must have.

> > > 5. The basic calculation is of the elapsed proper time over a (timelike)
> > > path through spacetime. When calculated in flat spacetime using an
> > > inertial frame, acceleration does not appear in the integral, but
> > > speed does.

But this does not explain what the cause is.

> > If you want to do it accurate you have to take all the speeds into account
> > involved (starting 'slowly' from zero to v and back at each dt) which
> > implies acceleration.
>
> What? Are you unable to read above?
>
> > The root cause is that the physical behaviour of clocks is affected by
> > speed.
>
> Total nonsense. If the atomic clock rate are not affected by acceleration,
> why would they be affected by speed?

If the atomic clock rate is not affected in some way by something then, when
they reunite the reading of the two clocks should be identical, which is in
conflict with the results of actual experiments?

> > > In the usual twin paradox, it is not possible for the traveling twin to
> > > return without experiencing acceleration.
> >
> > What the travelling twin B experience IMO is of no importance also not if B
> > truelly ages. What is important the clock B uses on the trip.
>

> Yeah right....
> This is a waste of time...PLONK

My problem is that I want to understand something.
I want to understand why there is a different in clock readings between
a stay at home clock versus a moving clock.
You can never explain that simply based on the lorentz transformations.
because the lorentz transformations are also a description of a process
and it is that process that I want to understand.
And because the difference between the two clocks is distance
the cause must be related to speed and or acceleration.
(But that does not mean there are two explanations)

Nicolaas Vroom

[Tom Roberts]

On 8/19/17 8/19/17 11:52 AM, Nicolaas Vroom wrote:
> Read page 167 of the book GRAVITATION
> "Exercise 6.3 Twin Paradox
> (a) show that of all timelike world lines connecting two events A and B the
> one with the longest lapse of proper time is the unaccelerated one (hint:
> perform the calculation in the inertial frame of the unaccelerated world line)
> (b) One twin chooses to move from A to B along the unaccelerated world line.
> Show that the other twin, by appropriate choice of accelerations can get from
> A to B in arbitrary small proper time"

So do the exercise. Then LOOK at the formulas you used -- acceleration does not
appear in them. If you follow the hint, you'll find that speed relative to that
frame does appear.

> [Twin paradox]

> The point is that the final readings are different, which implies that
> something must have happened inbetween.

Yes! They traveled different paths between the same endpoints; paths with
different path lengths (elapsed proper times). NOTHING "happened" to the clocks,
just to the PATHS.

>> Again, accelerations do not affect the clock ticking.
>
> But something must have.

No. "Something" happened TO THE PATHS.

> If the atomic clock rate is not affected in some way by something then, when
> they reunite the reading of the two clocks should be identical, which is in
> conflict with the results of actual experiments?

You repeatedly ignore the PATHS. Clocks measure the path length of their
trajectory through spacetime, and when they follow different paths they can
measure different path lengths. For timelike paths, path length is just elapsed
proper time.

> I want to understand why there is a different in clock readings between
> a stay at home clock versus a moving clock.

See above. The difference in clock readings is related to the different paths
they followed, not any effect on the clocks themselves.

> You can never explain that simply based on the lorentz transformations.
> because the lorentz transformations are also a description of a process
> and it is that process that I want to understand.

That "process" is simple geometry: different paths can have different path
lengths, and each clock measures the path length of its trajectory through
spacetime.

Tom Roberts

[Odd Bodkin]

kenseto <set...@att.net> wrote:
> On Friday, August 18, 2017 at 11:04:21 AM UTC-4, Paparios wrote:
>> El viernes, 18 de agosto de 2017, 11:07:44 (UTC-3), kenseto escribió:
>>> On Monday, August 14, 2017 at 11:56:47 AM UTC-4, Paparios wrote:
>>>> El lunes, 14 de agosto de 2017, 10:53:58 (UTC-3), Nicolaas Vroom escribió:
>>
>>>>
>>>> Take your 50x300cm ladder through a 70x200 cm door. The geometrical projection
>>>> of the ladder onto the door has to be less than 70x200cm to pass through. If
>>>> you take it horizontal, 200 > 70 means it will not pass. You rotate it so its
>>>> geometrical projection is 50x60cm and the ladder goes through without a problem.
>>>
>>> But after it went through the door via orientation can it be contained
>>> in a 70x200x200 cm barn briefly with both barn doors close simultaneously? I think not.
>>>
>>
>> If you are referring to the pole and barn paradox, then the ladder has to be
>> traveling at v=0.8c, for example. At that speed, an observer in the barn will
>> see the ladder to be length contracted and, for sure, to be fully contained
>> inside the barn with its doors closed.
>
> So that means material contraction but your SR brothers (Bodkin and Tom)
> said that there is no material contraction. Do you agree

Note that he did not say anything about material contraction, nor did
anything he said imply that. YOU are the one inserting "material" where it
isn't there.

>
>
>> The situation for the observer with the ladder is different. For him the ladder
>> has the same length it had before moving, but it will pass through the barn
>> unharmed, since the doors for that observer do not close at the same time
>> (due to relativity of simultaneity)
>>>
>>>>
>>>> That it means the ladder length changed from 300cm to 60cm? Of course not,
>>>> only its orientation in space did.
>>>>
>>>> Similarly, the traveling twin clock rate does not change in its path through
>>>> spacetime, but its geometrical projection does.
>>>>
>>>>
>>>>>>> But what about a moving clock i.e. when two clocks are moved along
>>>>>>> different path and when they meet the number of ticks is different?
>>>>>
>>>>> IMO that is something physical
>>>>>
>>>>>>> Nicolaas Vroom
>

[Paparios]

El sábado, 19 de agosto de 2017, 13:09:50 (UTC-3), kenseto escribió:
> On Saturday, August 19, 2017 at 11:34:34 AM UTC-4, kenseto wrote:
> > On Friday, August 18, 2017 at 11:04:21 AM UTC-4, Paparios wrote:
> > > El viernes, 18 de agosto de 2017, 11:07:44 (UTC-3), kenseto escribió:
> > > > On Monday, August 14, 2017 at 11:56:47 AM UTC-4, Paparios wrote:
> > > > > El lunes, 14 de agosto de 2017, 10:53:58 (UTC-3), Nicolaas Vroom escribió:
> > >
> > > > >
> > > > > Take your 50x300cm ladder through a 70x200 cm door. The geometrical projection
> > > > > of the ladder onto the door has to be less than 70x200cm to pass through. If
> > > > > you take it horizontal, 200 > 70 means it will not pass. You rotate it so its
> > > > > geometrical projection is 50x60cm and the ladder goes through without a problem.
> > > >
> > > > But after it went through the door via orientation can it be contained in a 70x200x200 cm barn briefly with both barn doors close simultaneously? I think not.
> > > >
> > >
> > > If you are referring to the pole and barn paradox, then the ladder has to be
> > > traveling at v=0.8c, for example. At that speed, an observer in the barn will
> > > see the ladder to be length contracted and, for sure, to be fully contained
> > > inside the barn with its doors closed.
> >
> > So that means material contraction but your SR brothers (Bodkin and Tom) said that there is no material >contraction. Do you agree
>
> The computer sends out my post before I was ready.
> So according to you, the pole is materially contracted but your SR brothers (Bodkin and Tom) said that there is no material contraction. Do you agree with Tom and Bodkin or do you believe that there was material contraction?
>

You snipped the second part of my post:

"The situation for the observer with the ladder is different. For him the ladder
has the same length it had before moving, but it will pass through the barn
unharmed, since the doors for that observer do not close at the same time

(due to relativity of simultaneity)".

Indeed nothing material happens to the ladder, so yes I agree with Tom and
Bodkin. If you were riding with the ladder, you would experience nothing
out of the ordinary. For you, however, the doors of the barn would not close
simultaneously: the front door (the one the ladder tip crosses when leaving
the barn) would close first (just before the ladder reaches it) and later the
back door would close (just after the ladder tail enters the barn).

[Paparios]

It has been explained before to you and tyhis will be my last one. Both clocks
at the end of the gedanken show the accumulated reading (total number of ticks)
due to their respective paths through spacetime and, since those path are
clearly different, those reading should also be different and they are.

[mlwo...@wp.pl]

W dniu sobota, 19 sierpnia 2017 22:05:01 UTC+2 użytkownik Paparios napisał:

> It has been explained before to you and tyhis will be my last one. Both clocks
> at the end of the gedanken show the accumulated reading (total number of ticks)
> due to their respective paths through spacetime and, since those path are
> clearly different, those reading should also be different and they are.

A lie, as expected from relativistic trash.
Yes, the readings should be different. No,
they are not (check it at GPS).

[mlwo...@wp.pl]

W dniu sobota, 19 sierpnia 2017 21:59:41 UTC+2 użytkownik Paparios napisał:

> Indeed nothing material happens to the ladder, so yes I agree with Tom and

Nothing material, you say. But you do know the atomic
bindings are electromagnetic, do you, poor idiot?

[Nicolaas Vroom]

On Saturday, 19 August 2017 00:08:29 UTC+2, tjrob137 wrote:
> On 8/16/17 8/16/17 9:25 AM, Nicolaas Vroom wrote:
> > On Wednesday, 9 August 2017 21:04:42 UTC+2, tjrob137 wrote:
> >> SR can certainly explain the twin paradox, quantitatively. Including
> >> instantaneous or finite accelerations. GR can be used as well, but in
> >> flat spacetime it of course gives results identical to those of SR.
> >>
> >> Acceleration most definitely is NOT the root cause:
> >

> > I do not understand this. (See bottom)

>
> Hmmmm. Note that muons experiencing 10^18 g as they go around a ring have
> the same lifetime measured in the lab as muons that travel at the same
> speed along a straight line with essentially no acceleration.
> So acceleration does not affect the timekeeping mechanism of muon decay.

Okay But muon decay is a physical process which has its own (quantum
mechanical) rules. Let us emphasize the experiments mentioned at page
167 of the book GRAVITATION in chapter 6 (Accelerated observers)
which are about to the Twin paradox.

> GPS satellite clocks are likewise unaffected by their acceleration,
> giving us confidence to apply the same idea to all clocks:
> they are unaffected by acceleration.

And that is only true if these clocks work based on muon decay and I
doubt that. Anyway GPS clocks require continuous synchronisation and
there must be a reason why.

> And that is how SR and GR model it.

IMO SR, GR and Newton's supply the descriptions in mathematical form
how the universe changes and evolves. The cause are primarily forces.

> >> 1. Good clocks are unaffected by acceleration (as long as they are not
> >> broken by it). Experiments show that the timekeeping mechanism
> >> governing muon decay is not affected by a proper acceleration of
> >> 10^18 g (!).
> >
> > The condition of the experiment should be such that after all the clocks
> > meet again they should all tick at the same rate.
>
> Can't be done. Experiments are what they are, not what you WISH them to be.

What I understand of all the experiments is when you start the experiments
you should test that all clocks tick at the same rate and when the experiment
is finished you should test again. Muon decay is a different process.

> >> 5. The basic calculation is of the elapsed proper time over a (timelike)
> >> path through spacetime. When calculated in flat spacetime using an
> >> inertial frame, acceleration does not appear in the integral, but
> >> speed does.
> >
> > If you want to do it accurate you have to take all the speeds into
> > account involved (starting 'slowly' from zero to v and back

> > at each dt) whichimplies acceleration.

>
> THIS calculation can handle arbitrary accelerations. But the
> accelerations do not contribute to the result, only the resulting path
> and its speed (relative to that inertial frame)
> contribute. That is, acceleration affects the path but not
> the calculation itself, but the calculation depends on the path.

Okay

> > The root cause is that the physical behaviour of clocks is affected
> > by speed.
>
> No! NOT AT ALL! Experiments show the opposite: speed does not affect
> the physical behavior of clocks.

Speed affects the innerworking and the positions of the dials on the
clock using light signals.
This is equivalent as the number of revolutions or ticks of the clocks.

> It only affects how observers MEASURE them.

Observing the time on the clock, the event of looking, has nothing to do
with the physical behaviour of a clock.
(It is the same as when you open the box)

> That, however, does not make it "imaginary", or "fictitious",
> or "illusory", because it can have real physical consequences
> (such as pion beams 1 km long being useful).
>
> If what you claim were true, Einstein's first postulate of SR
> could not possibly be valid. But myriad experiments show that
> SR is valid.

For a clock, based on the speed of light, it is important that the
speed of light is constant.
The more there is a discrepancy the less accurate this clock is,

> Tom Roberts
Thanks

Nicolaas Vroom

[kenseto]

On Saturday, August 19, 2017 at 3:59:41 PM UTC-4, Paparios wrote:
> El sábado, 19 de agosto de 2017, 13:09:50 (UTC-3), kenseto escribió:
> > On Saturday, August 19, 2017 at 11:34:34 AM UTC-4, kenseto wrote:
> > > On Friday, August 18, 2017 at 11:04:21 AM UTC-4, Paparios wrote:
> > > > El viernes, 18 de agosto de 2017, 11:07:44 (UTC-3), kenseto escribió:
> > > > > On Monday, August 14, 2017 at 11:56:47 AM UTC-4, Paparios wrote:
> > > > > > El lunes, 14 de agosto de 2017, 10:53:58 (UTC-3), Nicolaas Vroom escribió:
> > > >
> > > > > >
> > > > > > Take your 50x300cm ladder through a 70x200 cm door. The geometrical projection
> > > > > > of the ladder onto the door has to be less than 70x200cm to pass through. If
> > > > > > you take it horizontal, 200 > 70 means it will not pass. You rotate it so its
> > > > > > geometrical projection is 50x60cm and the ladder goes through without a problem.
> > > > >
> > > > > But after it went through the door via orientation can it be contained in a 70x200x200 cm barn briefly with both barn doors close simultaneously? I think not.
> > > > >
> > > >
> > > > If you are referring to the pole and barn paradox, then the ladder has to be
> > > > traveling at v=0.8c, for example. At that speed, an observer in the barn will
> > > > see the ladder to be length contracted and, for sure, to be fully contained
> > > > inside the barn with its doors closed.
> > >
> > > So that means material contraction but your SR brothers (Bodkin and Tom) said that there is no material >contraction. Do you agree
> >
> > The computer sends out my post before I was ready.
> > So according to you, the pole is materially contracted but your SR brothers (Bodkin and Tom) said that there is no material contraction. Do you agree with Tom and Bodkin or do you believe that there was material contraction?
> >
> You snipped the second part of my post:
>
> "The situation for the observer with the ladder is different. For him the ladder
> has the same length it had before moving, but it will pass through the barn
> unharmed, since the doors for that observer do not close at the same time
> (due to relativity of simultaneity)”.

But you said according to the barn observer the pole is completely inside the barn briefly with both doors closed simultaneously. This is only possible if the pole is materially contracted.