Inescapable (symmetric) twins paradox

[Julio Di Egidio]

Dear all,

"In the context of special relativity, we present a twins experiment that is
symmetric between the twins, so that a paradox appears inescapable, in the
form of a violation of the principle of causality. [...] Bottom line: if
special relativity is correct, it must be incomplete."

<http://seprogrammo.blogspot.co.uk/2015/07/symmetric-twins-paradox.html>

Feedback welcome,

Julio

[qw]

Why not putting it in "Nature"?

[paparios]

What you present is nothing new or original and it is wrong.
What SR says is that in the symmetric twins case, at the end of the journey, both clocks will show the same reading. So there is no a violation on causality or anything else.

[ju...@diegidio.name]

There is indeed a tabu on this one: all analyses I have managed to find are patent nonsense...

Julio

[Julio Di Egidio]

[Sorry, I forgot GG loses cross-posts.]

<j***@diegidio.name> wrote in message
news:7c82a541-61af-4cd4...@googlegroups.com...

[Maciej Woźniak]

Użytkownik napisał w wiadomości grup
dyskusyjnych:7c82a541-61af-4cd4...@googlegroups.com...

|There is indeed a tabu on this one: all analyses I have managed to find are
patent nonsense...

Remember 2 things:
All idiot physicist's tales about clocks don't match real clocks since
Einstein
All physicist's tales about observers don't match real observers since
Galileo.

They all are simply imagined and fabricated.

[Julio Di Egidio]

"paparios" <papa...@gmail.com> wrote in message
news:683a35de-42ce-4755...@googlegroups.com...
<snip>

> What you present is nothing new or original and it is wrong.
> What SR says is that in the symmetric twins case, at the end of the
> journey, both clocks will show the same reading. So there is no a
> violation on causality or anything else.

That is wrong: the clocks may show the same reading only relative to an
observer stationary with the origin all along...

Julio

[Dono,]

Proper time is frame - invariant, so, since the clocks show the same elapsed proper time wrt one frame, they WILL show the same elapsed proper time wrt ALL frames. You are grossly ignorant. Tough.

[Julio Di Egidio]

On Wednesday, July 15, 2015 at 4:19:16 PM UTC+1, Dono, wrote:
> On Wednesday, July 15, 2015 at 8:14:59 AM UTC-7, Julio Di Egidio wrote:

> > "paparios" <p***@gmail.com> wrote in message

> > news:683a35de-42ce-4755...@googlegroups.com...
> > <snip>
> > > What you present is nothing new or original and it is wrong.
> > > What SR says is that in the symmetric twins case, at the end of the
> > > journey, both clocks will show the same reading. So there is no a
> > > violation on causality or anything else.
> >
> > That is wrong: the clocks may show the same reading only relative to an
> > observer stationary with the origin all along...
>

> Proper time is frame - invariant, so, since the clocks show the same elapsed proper time wrt one frame, they WILL show the same elapsed proper time wrt ALL frames.

Wrong as well as not to the point.

> You are grossly ignorant. Tough.

You must be under a spell...

Julio

[Helmut Wabnig]

Yawn.

(That was my feedback)


You are 120 Years too late.

w.

[Dono,]

Cretin. Incurable.

[hanson]

"Julio Di Egidio" <ju...@diegidio.name> wrote:

hanson wrote:
Pentcho Valev posted one. A Great one! Yesterday in
Re: VERIFYING EINSTEIN'S CONSTANCY OF THE SPEED OF LIGHT
<https://www.youtube.com/watch?v=vwiayZ3sH7U >
wherein Edward Teller, the inventor of the H-Bomb, says:
>
___ "Einstein didn't know what he was talking about..."
___ "...or he was lying, or both".
>
Read also the comments under the video.
>
Then there is also this about
Relativity which is a pitiful **Physics by hear-say**
... a condemnation from already 60+ years ago,
2 years before he died, when...
<http://tinyurl.com/Einstein-denied-his-SR-and-GR
Albert concluded that:
____ SR is short for STUPID RANT _____ & that
____ GR stands for GULLIBLE RECITAL _____

[Dirk Van de moortel]

Julio Di Egidio schreef op 15-jul-2015 om 17:12:

Showing the same "reading relative to" another observer?
Silly.
Proper time IS the reading of a clock, BY DEFINITION.
So BY YOUR OWN EXPLICIT ASSUMPTIONS ["for some fixed
(appropriately long) proper time"], when the clocks
reunite, they show the same reading. Period.

Dirk Vdm

[Julio Di Egidio]

"Dirk Van de moortel" <dirkvand...@hotspam.not> wrote in message
news:mo5v6r$j2r$1...@speranza.aioe.org...

> Julio Di Egidio schreef op 15-jul-2015 om 17:12:
>> "paparios" <papa...@gmail.com> wrote in message
>> news:683a35de-42ce-4755...@googlegroups.com...
>> <snip>
>>> What you present is nothing new or original and it is wrong.
>>> What SR says is that in the symmetric twins case, at the end of the
>>> journey, both clocks will show the same reading. So there is no a
>>> violation on causality or anything else.
>>
>> That is wrong: the clocks may show the same reading only relative to an
>> observer stationary with the origin all along...
>
> Showing the same "reading relative to" another observer?
> Silly.

Indeed...

> Proper time IS the reading of a clock, BY DEFINITION.
> So BY YOUR OWN EXPLICIT ASSUMPTIONS ["for some fixed
> (appropriately long) proper time"], when the clocks
> reunite, they show the same reading. Period.

Relative to a third observer stationary with the origin all along... The
question (read the original article, not the snipping and nonsense) is what
R's clock looks to L, and what L's clock looks to R when they rejoin. In
fact, a third "stationary" observer adds nothing to the paradox and is not
even mentioned.

Julio

[Maciej Woźniak]

"Dirk Van de moortel" <dirkvand...@hotspam.not> wrote in message

> Proper time IS the reading of a clock, BY DEFINITION.

Yes, it is, and proper time of GPS is galilean:(
Good bye, Ingenious Shit.

[paparios]

Wrong again. Each of the twins observes his own clock ticking 1 sec/sec. So Twin A observes his own clock working as usual. Twin B does exactly the same. What SR says is that Twin B will measure the clock of twin A running slow and that Twin A will measure the clock of Twin B running slow. Notice that this requires a different frame for the measuring.

In your document you write that after the trip both twins are at the point of origin and they have stopped moving. Consequently neither clock is running slow with respect to the other.

[Dirk Van de moortel]

Julio Di Egidio schreef op 15-jul-2015 om 18:22:

Julio, you missed the /period/ in my reply.

If you don't know the jargon that is used in some field, and you
don't even understand the concepts, the safest best is to avoid
arguing about it altogether. PERIOD. <=== look, another one!

Dirk Vdm

[Maciej Woźniak]

Użytkownik "paparios" napisał w wiadomości grup
dyskusyjnych:eea04e5a-b460-46be...@googlegroups.com...

On Wednesday, July 15, 2015 at 12:14:59 PM UTC-3, Julio Di Egidio wrote:
> "paparios" <papa...@gmail.com> wrote in message
> news:683a35de-42ce-4755...@googlegroups.com...
> <snip>
> > What you present is nothing new or original and it is wrong.
> > What SR says is that in the symmetric twins case, at the end of the
> > journey, both clocks will show the same reading. So there is no a
> > violation on causality or anything else.
>
> That is wrong: the clocks may show the same reading only relative to an
> observer stationary with the origin all along...
>
> Julio

|Wrong again. Each of the twins observes his own clock ticking 1 sec/sec.

Physicist's tales of observer had nothing in common with reality
even in Galileo time.
A pure fantasy.
Physics never understood real mechanism of observation, so
fabricated instead a mechanism simple enough for it.

[Sam Wormley]

Quoting from your link, "(Effects of acceleration can be minimised by
making the total proper time the rockets are subject to acceleration
appropriately small relative to the total proper time of the journey.)

"The twins at that point rejoin, again sharing a common frame of
reference (up to arbitrary precision)."

NOPE -- Getting back together requires a switching of reference
frames (via acceleration) which mean NO PARADOX.

Here are the details:
> http://www.phys.vt.edu/~takeuchi/relativity/notes/section15.html




--

sci.physics is an unmoderated newsgroup dedicated
to the discussion of physics, news from the physics
community, and physics-related social issues.

[Maciej Woźniak]

Użytkownik "Sam Wormley" napisał w wiadomości grup
dyskusyjnych:25GdndY8pbscDzvI...@giganews.com...

| NOPE -- Getting back together requires a switching of reference
| frames (via acceleration) which mean NO PARADOX.

No, poor idiot. No thing in the world ever required and ever
will require your moronic "switching frames". One, observer
independent reference frame is enough for any reasonable
model.
Just another thing idiot physicist found necessary, because
so.

[shuba]

Julio wrote:

> <http://seprogrammo.blogspot.co.uk/2015/07/symmetric-twins-paradox.html>
>
> Feedback welcome,

No point attempting to straighten you out. The best idea would
be to study the subject and correct your own misunderstandings.

"I am a software analyst and programmer, with
some background in mathematics and philosophy."

from http://julio.diegidio.name/

Well in *that case* you may not want to bother with study.


---Tim Shuba---

[Sam Wormley]

On 7/15/15 12:18 PM, Maciej Woźniak wrote:
> No, poor idiot. No thing in the world ever required and ever
> will require your moronic "switching frames". One, observer
> independent reference frame is enough for any reasonable
> model.

See: http://www.phys.vt.edu/~takeuchi/relativity/notes/section15.html

[Odd Bodkin]

On 7/15/2015 12:18 PM, Maciej Woźniak wrote:
> One, observer
> independent reference frame is enough for any reasonable
> model.

I disagree, and I'm not a physicist.
Do that, and the laws of physics will change depending on your motion.
You think that's just fine and dandy. I don't.

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

[Maciej Woźniak]

Użytkownik "Sam Wormley" napisał w wiadomości grup

dyskusyjnych:25Gdnc88pbvdADvI...@giganews.com...

On 7/15/15 12:18 PM, Maciej Woźniak wrote:
> No, poor idiot. No thing in the world ever required and ever
> will require your moronic "switching frames". One, observer
> independent reference frame is enough for any reasonable
> model.


| See: http://www.phys.vt.edu/~takeuchi/relativity/notes/section15.html

What for? To see you're not the only brainwashed moron in the
world we inhabit?

[Odd Bodkin]

On 7/15/2015 1:04 PM, Maciej Woźniak wrote:
>
>
> What for? To see you're not the only brainwashed moron in the
> world we inhabit?
>

Anybody who believes he is humiliating anyone by calling them names is a
lost cause to humanity.

Maciej, you have greatly overestimated your importance, your impact, and
your general footprint in the world, I'm afraid.

[pcard...@volcanomail.com]

You write "To compute results, we apply special relativity." But then you don't apply relativity (and you don't actually compute anything), you apply hand waving and get a wrong answer. If you apply relativity, you will get the right answer; which is that relativity predicts that the two clocks would read the same.

[Koobee Wublee]

On Wednesday, July 15, 2015 at 8:08:21 AM UTC-7, paparios wrote:
> On Wednesday, July 15, 2015 at 11:55:53 AM UTC-3, Julio Di Egidio wrote:

> > "In the context of special relativity, we present a twins experiment that is
> > symmetric between the twins, so that a paradox appears inescapable, in the
> > form of a violation of the principle of causality. [...] Bottom line: if
> > special relativity is correct, it must be incomplete."
>
> > http://seprogrammo.blogspot.co.uk/2015/07/symmetric-twins-paradox.html
>

> What you present is nothing new or original and it is wrong.

What is wrong about design a scenario? <shrug>

> What SR says is that in the symmetric twins case, at the end of the
> journey, both clocks will show the same reading.

This is not what SR says. If insisting to be such an ass, please show some mathematics to support your claim. <shrug>

> So there is no a violation on causality or anything else.

There have been plenty of mathematics showing the scenario with both traveling twins to be a fatal contradiction to the Twin paradox. <shrug>

[Sylvia Else]

On 16/07/2015 12:53 AM, Julio Di Egidio wrote:
> Dear all,
>

> "In the context of special relativity, we present a twins experiment
> that is symmetric between the twins, so that a paradox appears
> inescapable, in the form of a violation of the principle of causality.
> [...] Bottom line: if special relativity is correct, it must be
> incomplete."
>
> <http://seprogrammo.blogspot.co.uk/2015/07/symmetric-twins-paradox.html>
>

> Feedback welcome,
>
> Julio
>
>

What I see is a description of an experiment, together with an assertion
as to the result of applying SR.

What I don't see is any math to support the assertion.

If you had presented the math, we could point to the errors you've made.

Sylvia.

[Koobee Wublee]

On Wednesday, July 15, 2015 at 10:23:05 PM UTC-7, Sylvia Else wrote:
> On 16/07/2015 12:53 AM, Julio Di Egidio wrote:

> > <http://seprogrammo.blogspot.co.uk/2015/07/symmetric-twins-paradox.html>

>
> If you had presented the math, we could point to the errors you've made.

Let's write down the Lorentz transform which describes how two observations, by observers 1 and 3 mutually observing 2, are related. <shrug>

** dt12 = (dt32 - v31 dx32 / c^2) / sqrt(1 - v31^2 / c^2)
** dx12 = (dx32 - v31 dt32) / sqrt(1 - v31^2 / c^2)
** dy12 = dy32
** dz12 = dz32

And (reciprocal form)

** dt32 = (dt12 - v13 dx12 / c^2) / sqrt(1 - v13^2 / c^2)
** dx32 = (dx12 - v13 dt12) / sqrt(1 - v13^2 / c^2)
** dy32 = dy12
** dz32 = dz12

Where

** dt12, dx12, dy12, dz12 = Observations of 2 by 1
** dt32, dx32, dy32, dz32 = Observations of 2 by 3
** v13 = velocity of 3 as observed by 1
** v31 = velocity of 1 as observed by 3
** v13 = - v31

It is trivial to simplify the equations above into the following (squaring each equation and subtract the three spatial ones from the temporal one). This is very much the textbook stuff in which Sylvia should find no objections so far. <shrug>

** dt12 = dt32 sqrt(1 - v32^2 / c^2)

And

** dt32 = dt12 sqrt(1 - v12^2 / c^2)

Where

** v12^2 / c^2 = (dx12/dt12)^2 + (dy12/dt12)^2 + (dz12/dt12)^2
** v32^2 / c^2 = (dx32/dt32)^2 + (dy32/dt32)^2 + (dz32/dt32)^2

Now, we have the twins A and B. When A is observing B, A = 1, and B = 2 and 3. So, the following is the applicable result of the above equations. <shrug>

** dtAB = dtBB sqrt(1 - vBB^2 / c^2)

And

** dtBB = dtAB sqrt(1 - vAB^2 / c^2)

Where

** A = 1
** B = 2, 3

The above equations can be simplified into the following. <shrug>

** dtAB = dtBB

And

** dtBB = dtAB sqrt(1 - vAB^2 / c^2)

Where

** vBB = 0

Thus, the intrinsic rate of time flow at B (tBB) is observed by A (tAB) to be the following:

** dtBB = dtAB = dtAB sqrt(1 - vAB^2 / c^2)

See the fatal contradiction, Sylvia? Good luck digging yourself out of this one. <shrug>

[Sylvia Else]

On 16/07/2015 3:55 PM, Koobee Wublee wrote:
> On Wednesday, July 15, 2015 at 10:23:05 PM UTC-7, Sylvia Else wrote:
>> On 16/07/2015 12:53 AM, Julio Di Egidio wrote:
>
>>> <http://seprogrammo.blogspot.co.uk/2015/07/symmetric-twins-paradox.html>
>>
>> If you had presented the math, we could point to the errors you've made.
>
> Let's write down the Lorentz transform which describes how two observations, by observers 1 and 3 mutually observing 2, are related. <shrug>
>
> ** dt12 = (dt32 - v31 dx32 / c^2) / sqrt(1 - v31^2 / c^2)
> ** dx12 = (dx32 - v31 dt32) / sqrt(1 - v31^2 / c^2)
> ** dy12 = dy32
> ** dz12 = dz32

Step 1. Define you terms. Forcing the reader to make an educated guess
leaves you wiggle room for later.

Sylvia.

[Sylvia Else]

Yes, and all of it has been trivially wrong.

Sylvia.

[JanPB]

On Wednesday, July 15, 2015 at 7:55:53 AM UTC-7, Julio Di Egidio wrote:
> Dear all,
>

> "In the context of special relativity, we present a twins experiment that is
> symmetric between the twins, so that a paradox appears inescapable, in the
> form of a violation of the principle of causality. [...] Bottom line: if
> special relativity is correct, it must be incomplete."
>
> <http://seprogrammo.blogspot.co.uk/2015/07/symmetric-twins-paradox.html>
>

> Feedback welcome,
>
> Julio

I suggest you learn special relativity. No, I'm not joking! It's simply
true in general that in order to form a valid opinion about X, one should
understand X first.

--
Jan

[Julio Di Egidio]

"Sylvia Else" <syl...@not.at.this.address> wrote in message
news:d0otdm...@mid.individual.net...

> On 16/07/2015 12:53 AM, Julio Di Egidio wrote:

<snip>
>> <http://seprogrammo.blogspot.co.uk/2015/07/symmetric-twins-paradox.html>

>
> What I see is a description of an experiment, together with an assertion
> as to the result of applying SR.

That is correct: the result is obvious, the consequences are not obvious.

> What I don't see is any math to support the assertion.
>
> If you had presented the math, we could point to the errors you've made.

This is not a maths forum: anyway, if you knew anything about special
relativity, you would not need to ask.

Julio

[Julio Di Egidio]

"Koobee Wublee" <koobee...@gmail.com> wrote in message
news:0017b8ac-1934-4d57...@googlegroups.com...

> There have been plenty of mathematics showing the scenario with both
> traveling twins to be a fatal contradiction to the Twin paradox

Thanks for the feedback, Koobee. Why fatal? I am thinking the paradox can
be resolved and causality embraced: the world would not get any less weird,
in fact somehow more, but it would be consistent with logic as well as
amenable to some serious philosophy... Unless you do not accept the
constancy of the speed of light at all?

Julio

[Sylvia Else]

The math of special relativity is only high-school algebra, and plenty
of it gets posted to this forum. Your conclusion that there's a
contradiction certainly arises from an incorrect application of the
Lorentz transform. If you can't, or won't, post your math here, we can
only conclude that either you can't do the math anyway, or know very
well that it's wrong.

Sylvia.

[kefischer]

The outcome of the twins parting is
about as significant as a flea getting mashed.

[Gary Harnagel]

On Thursday, July 16, 2015 at 3:07:37 AM UTC-6, Julio Di Egidio wrote:
>
> "Sylvia Else" <syl...@not.at.this.address> wrote in message
> news:d0otdm...@mid.individual.net...
> >

> > What I see is a description of an experiment, together with an assertion
> > as to the result of applying SR.
>
> That is correct: the result is obvious, the consequences are not obvious.
>
> > What I don't see is any math to support the assertion.
> >
> > If you had presented the math, we could point to the errors you've made.
>
> This is not a maths forum: anyway, if you knew anything about special
> relativity, you would not need to ask.
>
> Julio

The question is NOT whether Sylvia knows anything about SR. The question
is, do you?

"Koobee Wublee" wrote:

> > There have been plenty of mathematics showing the scenario with both
> > traveling twins to be a fatal contradiction to the Twin paradox
>
> Thanks for the feedback, Koobee.

You realize, don't you, that you are talking to a complete loon, don't you?
K-dub's logic is what's fatally-flawed.

> Why fatal? I am thinking the paradox can be resolved

The "paradox HAS been resolved, but you need to use logic (a part of
mathematics) plus some algebra to resolve it.

> and causality embraced: the world would not get any less weird,
> in fact somehow more, but it would be consistent with logic

The TP is consistent with logic.

> as well as amenable to some serious philosophy... Unless you do not
> accept the constancy of the speed of light at all?

And there are loons around here that deny that, too. They are reality-
deniers.

Gary

[Michael Moroney]

If you knew about special relativity, you'd do the math, show it, and find
out that the two twins would be the same age (but younger than a
hypothetical triplet left behind on the planet).

[Odd Bodkin]

On 7/16/2015 12:16 AM, Koobee Wublee wrote:
>> >What SR says is that in the symmetric twins case, at the end of the
>> >journey, both clocks will show the same reading.
> This is not what SR says. If insisting to be such an ass, please show some mathematics to support your claim. <shrug>
>

I believe this has been done for you. And when that happened, as has
happened in other cases, you have demonstrated that you don't know how
to do the basic mathematics of the Lorentz transform.

You are mathematically incompetent, despite your bluster.

[Odd Bodkin]

Julio, in order to work out the consequences of any physical theory, you
have to do the math. This is why math is part and parcel of physics. It
is simply not possible to competently work out the consequences of
relativity if you can't do the math of relativity. I think that's the
caution that Sylvia is putting out to you. If you now say that you don't
believe that math should be a required skill to work out the outcomes
and consequences of a theory, then it's quite likely you'll lose the
interest of your readers.

>
> Julio

[Maciej Woźniak]

Użytkownik "Sylvia Else" napisał w wiadomości grup
dyskusyjnych:d0p0jj...@mid.individual.net...

Step 0, Sylvia. Define "define".

[Maciej Woźniak]

Użytkownik "Sylvia Else" napisał w wiadomości grup

dyskusyjnych:d0pbut...@mid.individual.net...

|The math of special relativity is only high-school algebra, and plenty
|of it gets posted to this forum.

Show me the place, where high school algebra defines terms
"time", "distance" "simultaneity" or "light speed".

[benj]

Julio, Boinker can't understand that math is nothing but fantasy. It
can't sink into his thick skull that when your assumptions are wrong,
your math is "wrong" (but "right" as mathematics). He's just snowed.


--
___ ___ ___ ___
/\ \ /\ \ /\__\ /\ \
/::\ \ /::\ \ /::| | \:\ \
/:/\:\ \ /:/\:\ \ /:|:| | ___ /::\__\
/::\~\:\__\ /::\~\:\ \ /:/|:| |__ /\ /:/\/__/
/:/\:\ \:|__| /:/\:\ \:\__\ /:/ |:| /\__\ \:\/:/ /
\:\~\:\/:/ / \:\~\:\ \/__/ \/__|:|/:/ / \::/ /
\:\ \::/ / \:\ \:\__\ |:/:/ / \/__/
\:\/:/ / \:\ \/__/ |::/ /
\_:/__/ \:\__\ /:/ /
\/__/ \/__/

[Sam Wormley]

Those are common terms used in physics. The algebra is used by the
physics student to calculate quantities in relationships of the
physics.

Maciej, can you calculate the force between to masses M1 and M2
separated by a distance d? The physics concept is Newton Law of
Gravitation. The algebra is the tool to calculate the force of
gravity.

[Maciej Woźniak]

Użytkownik "Sam Wormley" napisał w wiadomości grup
dyskusyjnych:CN6dnYfmIJ2vTDrI...@giganews.com...

On 7/16/15 10:24 AM, Maciej Woźniak wrote:
>
>
> Użytkownik "Sylvia Else" napisał w wiadomości grup
> dyskusyjnych:d0pbut...@mid.individual.net...
>
> |The math of special relativity is only high-school algebra, and plenty
> |of it gets posted to this forum.
>
> Show me the place, where high school algebra defines terms
> "time", "distance" "simultaneity" or "light speed".
>

| Those are common terms used in physics.

Yes. And they are not terms of high school algebra.
Your math is not high school algebra. Though, it's
inheriting.

[Odd Bodkin]

Right. Like Newtonian math F=dp/dt and F_g = GMm/r^2 is fantasy and has
nothing to do with reality.

[Koobee Wublee]

On Wednesday, July 15, 2015 at 11:17:27 PM UTC-7, Sylvia Else wrote:
> On 16/07/2015 3:55 PM, Koobee Wublee wrote:

> > Let's write down the Lorentz transform which describes how two
> > observations, by observers 1 and 3 mutually observing 2, are
> > related. <shrug>
>
> > ** dt12 = (dt32 - v31 dx32 / c^2) / sqrt(1 - v31^2 / c^2)
> > ** dx12 = (dx32 - v31 dt32) / sqrt(1 - v31^2 / c^2)
> > ** dy12 = dy32
> > ** dz12 = dz32
>

> Step 1. Define you terms.

Already defined that Sylvia has maliciously snipped. <shrug>

> Forcing the reader to make an educated guess leaves you wiggle room
> for later.

How much is Sylvia getting paid for this lip service? If nothing, then a very cheap whore. <shrug>

[Koobee Wublee]

They are not wrong but just dismissed by the ones who have called themselves scientists and very cheap whores like Sylvia. <shrug>

[Koobee Wublee]

On Thursday, July 16, 2015 at 12:14:49 AM UTC-7, JanPB wrote:
> On Wednesday, July 15, 2015 at 7:55:53 AM UTC-7, Julio Di Egidio wrote:

> > http://seprogrammo.blogspot.co.uk/2015/07/symmetric-twins-paradox.html

>
> I suggest you learn special relativity.

That is a great suggestion for yourself as well. <shrug>

> No, I'm not joking!

Neither is Koobee Wublee. <shrug>

> It's simply true in general that in order to form a valid opinion about
> X, one should understand X first.

Absolutely. The problem is that Jan the relativistic moron is the biggest abuser of the above. <shrug>

[qw]

Koobee Wublee wrote:

>> > Thus, the intrinsic rate of time flow at B (tBB) is observed by A
>> > (tAB) to be the following:
>>
>> > ** dtBB = dtAB = dtAB sqrt(1 - vAB^2 / c^2)
>>
>> Step 1. Define you terms.
>
> Already defined that Sylvia has maliciously snipped. <shrug>
>
>> Forcing the reader to make an educated guess leaves you wiggle room for
>> later.
>
> How much is Sylvia getting paid for this lip service? If nothing, then
> a very cheap whore. <shrug>

Silvia is just another one not understanding Tensors. Amazingly, people
are coming here pretending (or expecting) understanding modern theories.
But without rigorous prerequisites in Differential Geometry and tensors,
there is no hope to understand anything.

Einstein was smart realizing it. Therefore he phoned his friends to help
him in his tensors.

[Koobee Wublee]

On Thursday, July 16, 2015 at 2:22:18 AM UTC-7, Julio Di Egidio wrote:

> "Koobee Wublee" wrote:

> > There have been plenty of mathematics showing the scenario with both
> > traveling twins to be a fatal contradiction to the Twin paradox
>
> Thanks for the feedback, Koobee. Why fatal?

Because the Twin paradox is a contradiction that will case the religion of SR to crumble. That means SR IS WRONG. <shrug>

> I am thinking the paradox can be resolved and causality embraced:

Keep brain storming. <shrug>

> the world would not get any less weird, in fact somehow more, but it
> would be consistent with logic as well as amenable to some serious
> philosophy...

You always allow science to take you wherever not take science to where you want to go. <shrug>

> Unless you do not accept the constancy of the speed of light at all?

Koobee Wublee pays close attentions to scientific method. <shrug>

[Odd Bodkin]

On 7/16/2015 11:54 AM, Koobee Wublee wrote:
> Koobee Wublee pays close attentions to scientific method. <shrug>

As well as grammar....

Koobee Wublee is also of the opinion that He is not capable of making
mistakes because of His divinity, and that anyone who claims Koobee has
made a mistake is merely denying His divinity.

[Koobee Wublee]

On Thursday, July 16, 2015 at 2:31:11 AM UTC-7, Sylvia Else wrote:
> On 16/07/2015 7:05 PM, Julio Di Egidio wrote:

> > This is not a maths forum: anyway, if you knew anything about special
> > relativity, you would not need to ask.
>

> The math of special relativity is only high-school algebra, and plenty
> of it gets posted to this forum. Your conclusion that there's a
> contradiction certainly arises from an incorrect application of the
> Lorentz transform. If you can't, or won't, post your math here, we can
> only conclude that either you can't do the math anyway, or know very
> well that it's wrong.

The high school mathematics below shows such fatal contradictions in the Lorentz transform. <shrug>

https://groups.google.com/d/msg/sci.physics.relativity/7KgNzGFOYNI/zFX6zEP7VZIJ

[Koobee Wublee]

The Lorentz transform is able to predict all accounts. The buffoons who have called themselves scientists just ignore some certain predictions that would show such fatal contradiction to SR. <shrug>

https://groups.google.com/d/msg/sci.physics.relativity/7KgNzGFOYNI/zFX6zEP7VZIJ

You cannot ignore such contradictions in science. After SR is shown wrong, the religion of SR will crumble, and the self-styled physicists would have to find another buffoon to worship instead of Einstein the nitwit, the plagiarist, and the liar. <shrug>

[Koobee Wublee]

On Thursday, July 16, 2015 at 6:47:54 AM UTC-7, Odd Bodkin wrote:
> On 7/16/2015 12:16 AM, Koobee Wublee wrote:

> > This is not what SR says. If insisting to be such an ass, please
> > show some mathematics to support your claim. <shrug>
>
> I believe this has been done for you.

All debunked by Koobee Wublee. <shrug>

> And when that happened, as has happened in other cases, you have
> demonstrated that you don't know how to do the basic mathematics
> of the Lorentz transform.

On the contrary, Koobee Wublee had shown exactly where mathemaGic tricks are played in these pathetic, wrong resolution to the Twin paradox. <shrug>

> You are mathematically incompetent, despite your bluster.

That's Odd Bodkin aka PD for you. <shrug>

[Julio Di Egidio]

On Thursday, July 16, 2015 at 5:54:10 PM UTC+1, Koobee Wublee wrote:
> On Thursday, July 16, 2015 at 2:22:18 AM UTC-7, Julio Di Egidio wrote:
> > "Koobee Wublee" wrote:
>
> > > There have been plenty of mathematics showing the scenario with both
> > > traveling twins to be a fatal contradiction to the Twin paradox
> >
> > Thanks for the feedback, Koobee. Why fatal?
>
> Because the Twin paradox is a contradiction that will case the religion of SR to crumble. That means SR IS WRONG. <shrug>

The twins paradox *per se* is not fatal...

> > I am thinking the paradox can be resolved and causality embraced:
>
> Keep brain storming. <shrug>
>
> > the world would not get any less weird, in fact somehow more, but it
> > would be consistent with logic as well as amenable to some serious
> > philosophy...
>
> You always allow science to take you wherever not take science to where you want to go. <shrug>
>
> > Unless you do not accept the constancy of the speed of light at all?
>
> Koobee Wublee pays close attentions to scientific method. <shrug>

Don't bullshit me, I am not brainstorming either: do you have a more precise answer than that?

Julio

[Odd Bodkin]

On 7/16/2015 12:05 PM, Koobee Wublee wrote:
> On Thursday, July 16, 2015 at 6:47:54 AM UTC-7, Odd Bodkin wrote:
>> On 7/16/2015 12:16 AM, Koobee Wublee wrote:
>
>>> This is not what SR says. If insisting to be such an ass, please
>>> show some mathematics to support your claim. <shrug>
>>
>> I believe this has been done for you.
>
> All debunked by Koobee Wublee. <shrug>
>
>> And when that happened, as has happened in other cases, you have
>> demonstrated that you don't know how to do the basic mathematics
>> of the Lorentz transform.
>
> On the contrary, Koobee Wublee had shown exactly where mathemaGic tricks

MathemaGic is the word the Koobee Wublee uses for mathematics that goes
over his head.

> are played in
> these pathetic, wrong resolution to the Twin paradox. <shrug>

How does it feel that a woodworker has a better grip on the mathematics
than you do, a CalTech graduate?

>
>> You are mathematically incompetent, despite your bluster.
>
> That's Odd Bodkin aka PD for you. <shrug>
>

[Koobee Wublee]

> > Thus, the intrinsic rate of time flow at B (tBB) is observed by A
> > (tAB) to be the following:
>
> > ** dtBB = dtAB = dtAB sqrt(1 - vAB^2 / c^2)
>

> > See the fatal contradiction, Sylvia? Good luck digging yourself out
> > of this one. <shrug>

> MathemaGic is the word the Koobee Wublee uses for mathematics that goes
> over his head.

Odd Bodkin aka PD cannot read or understand the simple math. <shrug>

> How does it feel that a woodworker has a better grip on the mathematics
> than you do, a CalTech graduate?

Odd Bodkin aka PD certainly has a very creative imagination. Smoking too much ganja stuff again? <shrug>

[Gary Harnagel]

On Thursday, July 16, 2015 at 10:56:48 AM UTC-6, Koobee Wublee wrote:
>
> The high school mathematics below shows such fatal contradictions in the
> Lorentz transform. <shrug>
>
> https://groups.google.com/d/msg/sci.physics.relativity/7KgNzGFOYNI/zFX6zEP7VZIJ

Au contraire, it shows the fatal ignorance of the one doing the calcs. And
K-dub's stamp of approval on it proves that he is also fatally ignorant.

"You are not entitled to your opinion. You are entitled to your informed
opinion. No one is entitled to be ignorant." -- Harlan Ellison

The point of "making the deceleration small" is where the ignorance sets in.
It is sophomoric to believe that nothing happens during that period, even
when it is made very small. K-dub should know this as it has been explained
to him ad nauseam, but he remains persistently and willfully ignorant.

Is K-dub REALLY a Caltech grad? I don't believe it!

Gary

[Julio Di Egidio]

On Thursday, July 16, 2015 at 6:58:38 PM UTC+1, Gary Harnagel wrote:

> The point of "making the deceleration small" is where the ignorance sets in.
> It is sophomoric to believe that nothing happens during that period, even
> when it is made very small.

That is indeed how they usually hand-wave their way out of it: "gravity!", as if that changed anything... The point of setting up a symmetric experiment was indeed just that, to by-pass that nonsense and use plain special relativity. The other point is that you *have* to (re-)do the basic calculations and realise (think!) what the heck is actually going on in SR, with time dilation and so on, given that the Lorentz transformations are perfectly symmetric between inertial frames! Then, among other things, you would see how time travel in the future is pure nonsense: the guy who travels comes back younger as seen by the one who stayed, but the one who stayed looks younger as seen by the one who travelled...

Julio

[rotchm]

That setup is not new. It is a well know gedanken. The conclusion, is that the clocks (twins) reunite with the same values.

Note that if you invoke accelerations (of the twins) then *you cant* apply SR from within their frames since their frames are NON INERTIAL. Making the accelerations brief (and huge) wont make that disappear, they remain non inertial (and hence the definition of position and time have not even been defined in such frames!); you need GR and to specify which metric you which to use for each of their frames (and what definition of position and time too!).

You can remove the accelerations with a third (and fourth twin), and where all twins are inertial. In such case, SR predicts that wrt each of the returning/ coinciding, their clocks will indicate the same value.

[Maciej Woźniak]

Użytkownik "rotchm" napisał w wiadomości grup
dyskusyjnych:5e49013c-dd89-4f14...@googlegroups.com...

|you need GR and to specify which metric you which to use for each of their
frames (and what definition of position and time too!).

We don't need your insane shit to anything,
and your tales of clocks have nothing in common with reality.

[Julio Di Egidio]

On Thursday, July 16, 2015 at 7:45:57 PM UTC+1, rotchm wrote:

> That setup is not new. It is a well know gedanken. The conclusion, is that the clocks (twins) reunite with the same values.

For the last time, that is plain wrong: if we had a third observer stationary with the origin, she and only she would see L and R's clocks in synch with each other. In fact, adding observers changes nothing: still the clocks would be late relative to her own clock, and still the twins would see *her* clock late relative to their own...

> Note that if you invoke accelerations

<snip>

I am not the one invoking accelerations...

Julio

[qw]

rotchm wrote:

> You can remove the accelerations with a third (and fourth twin), and
> where all twins are inertial. In such case, SR predicts that wrt each of
> the returning/ coinciding, their clocks will indicate the same value.

Only IFF the integration of the acceleration profile, for all those
distinct journeys, evaluates to same value. You dont need to remove
anything.

[kefischer]

The only thing he has a good grip on,
is probably between his legs. :-)

[kefischer]

Are you a salad chef?

Looks like it.

[underante]

On Thursday, July 16, 2015 at 6:55:12 AM UTC+1, Koobee Wublee wrote:
> On Wednesday, July 15, 2015 at 10:23:05 PM UTC-7, Sylvia Else wrote:

> > On 16/07/2015 12:53 AM, Julio Di Egidio wrote:
>
> > > <http://seprogrammo.blogspot.co.uk/2015/07/symmetric-twins-paradox.html>
> >

> > If you had presented the math, we could point to the errors you've made.
>

> Let's write down the Lorentz transform which describes how two observations, by observers 1 and 3 mutually observing 2, are related. <shrug>
>

> ** dt12 = (dt32 - v31 dx32 / c^2) / sqrt(1 - v31^2 / c^2) <--- eqn1
> ** dx12 = (dx32 - v31 dt32) / sqrt(1 - v31^2 / c^2) <---- eqn2

> ** dy12 = dy32
> ** dz12 = dz32
>
> And (reciprocal form)
>
> ** dt32 = (dt12 - v13 dx12 / c^2) / sqrt(1 - v13^2 / c^2)
> ** dx32 = (dx12 - v13 dt12) / sqrt(1 - v13^2 / c^2)
> ** dy32 = dy12
> ** dz32 = dz12
>
> Where
>
> ** dt12, dx12, dy12, dz12 = Observations of 2 by 1
> ** dt32, dx32, dy32, dz32 = Observations of 2 by 3
> ** v13 = velocity of 3 as observed by 1
> ** v31 = velocity of 1 as observed by 3
> ** v13 = - v31
>
> It is trivial to simplify the equations above into the following (squaring each equation and subtract the three spatial ones from the temporal one). This is very much the textbook stuff in which Sylvia should find no objections so far. <shrug>
>

> ** dt12 = dt32 sqrt(1 - v32^2 / c^2) <---- eqn3

>
> And
>
> ** dt32 = dt12 sqrt(1 - v12^2 / c^2)
>
> Where
>
> ** v12^2 / c^2 = (dx12/dt12)^2 + (dy12/dt12)^2 + (dz12/dt12)^2

> ** v32^2 / c^2 = (dx32/dt32)^2 + (dy32/dt32)^2 + (dz32/dt32)^2 <-----eqn4

erm, no doubt it is all trivial as you say, but sadly i don't quite see how that last expression for dt12 is arrived at (eqn3.)
if you go back to the start, put c = 1, then do the squaring and subtracting business on eqn1 and eqn2 that gives as expected:

** [dt32]^2 - [dt12]^2 = [dx32]^2 - [dx12]^2 -- eqn5

however if you square eqn3 and rearrange terms a bit to give:

** [dt32]^2 = [dt12]^2 + [v32]^2 * [dt32]^2 ---- eqn6

if yiou then use eqn4 to substitute for v32 that gives:

** [dt32]^2 - [dt12]^2 = [dx32]^2 + [dy32]^2 + [dz32]^2 --- eqn7

which sadly does not appear to match very well with eqn5
help?

[benj]

You are correct but so brainwashed like Boinker you don't know you are
correct! So what exactly is a "dp/dt" anyway? Where do I find one to
measure? I presume you think Newton's law of gravitation "explains"
gravity? You need to think a bit more.

[Gary Harnagel]

On Thursday, July 16, 2015 at 12:24:07 PM UTC-6, Julio Di Egidio wrote:
>
> On Thursday, July 16, 2015 at 6:58:38 PM UTC+1, Gary Harnagel wrote:
> >
> > The point of "making the deceleration small" is where the ignorance sets in.
> > It is sophomoric to believe that nothing happens during that period, even
> > when it is made very small.
>
> That is indeed how they usually hand-wave their way out of it:

It's not a "hand wave," Julio, it's MATHEMATICS and LOGIC.

> "gravity!", as if that changed anything...

That's ONE way to resolve it, but not the only way:

http://www.npl.washington.edu/AV/altvw38.html

> The point of setting up a symmetric experiment was indeed just that, to
> by-pass that nonsense and use plain special relativity.

What is your definition of "plain"? If it ignores acceleration (i.e.,
changing from one frame to another), then YOU are the one creating nonsense.

> The other point is that you *have* to (re-)do the basic calculations and
> realise (think!) what the heck is actually going on in SR,

I thought. Apparently, you haven't.

> with time dilation and so on,

Actually, the fact of non-simultaneity.

> given that the Lorentz transformations are perfectly symmetric between
> inertial frames!

Yes, they are; however, what does "symmetric" mean when you have FOUR
different inertial frames? See? YOU are the one not thinking.

> Then, among other things, you would see how time travel in the future is
> pure nonsense:

We're ALL traveling into the future at 1 second per second. Relativity
demonstrates, however, that simultaneity cannot be maintained across frames.

> the guy who travels comes back younger as seen by the one who stayed, but
> the one who stayed looks younger as seen by the one who travelled...
>
> Julio

This is false, as a correct analysis of the scenario demonstrates, it is
NOT symmetrical.

Gary

[Koobee Wublee]

On Thursday, July 16, 2015 at 1:20:55 PM UTC-7, underante wrote:

> Koobee Wublee wrote:

> > Let's write down the Lorentz transform which describes how two
> > observations, by observers 1 and 3 mutually observing 2, are
> > related. <shrug>
>
> > ** dt12 = (dt32 - v31 dx32 / c^2) / sqrt(1 - v31^2 / c^2)

> > ** dx12 = (dx32 - v31 dt32) / sqrt(1 - v31^2 / c^2)

> > ** dy12 = dy32
> > ** dz12 = dz32
>
> > And (reciprocal form)
>
> > ** dt32 = (dt12 - v13 dx12 / c^2) / sqrt(1 - v13^2 / c^2)
> > ** dx32 = (dx12 - v13 dt12) / sqrt(1 - v13^2 / c^2)
> > ** dy32 = dy12
> > ** dz32 = dz12
>
> > Where
>
> > ** dt12, dx12, dy12, dz12 = Observations of 2 by 1
> > ** dt32, dx32, dy32, dz32 = Observations of 2 by 3
> > ** v13 = velocity of 3 as observed by 1
> > ** v31 = velocity of 1 as observed by 3
> > ** v13 = - v31
>
> > It is trivial to simplify the equations above into the following
> > (squaring each equation and subtract the three spatial ones from
> > the temporal one). This is very much the textbook stuff in which
> > Sylvia should find no objections so far. <shrug>
>
> > ** dt12 = dt32 sqrt(1 - v32^2 / c^2)
>

> > And
>
> > ** dt32 = dt12 sqrt(1 - v12^2 / c^2)
>
> > Where
>
> > ** v12^2 / c^2 = (dx12/dt12)^2 + (dy12/dt12)^2 + (dz12/dt12)^2
> > ** v32^2 / c^2 = (dx32/dt32)^2 + (dy32/dt32)^2 + (dz32/dt32)^2
>

> > Now, we have the twins A and B. When A is observing B, A = 1, and
> > B = 2 and 3. So, the following is the applicable result of the
> > above equations. <shrug>
>
> > ** dtAB = dtBB sqrt(1 - vBB^2 / c^2)
>
> > And
>
> > ** dtBB = dtAB sqrt(1 - vAB^2 / c^2)
>
> > Where
>
> > ** A = 1
> > ** B = 2, 3
>
> > The above equations can be simplified into the following. <shrug>
>
> > ** dtAB = dtBB
>
> > And
>
> > ** dtBB = dtAB sqrt(1 - vAB^2 / c^2)
>
> > Where
>
> > ** vBB = 0
>
> > Thus, the intrinsic rate of time flow at B (tBB) is observed by A
> > (tAB) to be the following:
>
> > ** dtBB = dtAB = dtAB sqrt(1 - vAB^2 / c^2)
>
> > See the fatal contradiction, Sylvia? Good luck digging yourself out
> > of this one. <shrug>
>

> erm, no doubt it is all trivial as you say, but sadly i don't quite see
> how that last expression for dt12 is arrived at (eqn3.)

Let's assign the equations:

1) dt12 = (dt32 - v31 dx32 / c^2) / sqrt(1 - v31^2 / c^2)
2) dx12 = (dx32 - v31 dt32) / sqrt(1 - v31^2 / c^2)
3) dy12 = dy32
4) dz12 = dz32

Square each equations above, and subtract the sum of equations 2 to 4 squared from equation 1 squared:

** equ(1)^2 - equ(2)^2 - equ(3)^2 - equ(4)^2

Or

** c^2 dt12^2 - dx12^2 - dy^12 - dz12^2 = c^2 dt32^2 - dx32^2 - dy^32 - dz32^2

Or

** c^2 dt12^2 - v12^2 dt12^2 = c^2 dt32^2 - v32^2 dt32^2

Or

** dt12^2 (1 - v12^2 / c^2) = c^2 dt32^2 (1 - v32^2 / c^2)

Where

** v12^2 dt12^2 = (dx12)^2 + (dy12)^2 + (dz12)^2
** v32^2 dt32^2 = (dx32)^2 + (dy32)^2 + (dz32)^2

Notice v13 and v31 vanish. This is exactly how Minkowski was able to derive spacetime from the Lorentz transform. Although Larmor's transform is mathematically similar but drastically different in extreme boundaries, spacetime derived from Larmor's transform is mathematically no different from the spacetime derived from the Lorentz transform. Larmor's transform is an antithesis to the Lorentz transform. Larmor's transform demands the very existence of the Aether. <shrug>

[Odd Bodkin]

Really? You don't know how to measure momentum?
You don't know how to do repeated measurements of momentum over time?
You don't know how to measure a rate of change of a value of a
measurement done repeatedly over time?

Such a shame you were never taught how to measure anything.

> Where do I find one to
> measure? I presume you think Newton's law of gravitation "explains"
> gravity? You need to think a bit more.
>
>
>


--

[Dono,]

On Thursday, July 16, 2015 at 11:45:57 AM UTC-7, rotchm wrote:
> That setup is not new. It is a well know gedanken. The conclusion, is that the clocks (twins) reunite with the same values.
>
> Note that if you invoke accelerations (of the twins) then *you cant* apply SR from within their frames since their frames are NON INERTIAL.

This is, of course, false. SR deals with accelerated motion just fine. Case and point, see the treatment of TP for accelerated motion:

https://en.wikipedia.org/wiki/Twin_paradox#Difference_in_elapsed_time_as_a_result_of_differences_in_twins.27_spacetime_paths

See, the calculations from the frame(s) of the accelerated twin:

https://en.wikipedia.org/wiki/Twin_paradox#Difference_in_elapsed_times:_how_to_calculate_it_from_the_ship

> you need GR and to specify which metric you which to use for each of their frames (and what definition of position and time too!).
>

No, you don't, Stephane. See above.
You need to stop pretending that you know what you are talking about. Because you obviously don't.

[Sylvia Else]

On 16/07/2015 12:53 AM, Julio Di Egidio wrote:

> Dear all,
>
> "In the context of special relativity, we present a twins experiment
> that is symmetric between the twins, so that a paradox appears
> inescapable, in the form of a violation of the principle of causality.
> [...] Bottom line: if special relativity is correct, it must be
> incomplete."
>
> <http://seprogrammo.blogspot.co.uk/2015/07/symmetric-twins-paradox.html>
>
> Feedback welcome,
>
> Julio
>
>
At this juncture, I wonder at your motives for posting.

Did you really think your claim would be taken on trust?

Did you not expect that people would want to see your math?

Or was it your goal just to create yet another pointless thread?

Sylvia.

[Sam Wormley]

On 7/15/15 1:04 PM, Maciej Woźniak wrote:
>
>
> Użytkownik "Sam Wormley" napisał w wiadomości grup
> dyskusyjnych:25Gdnc88pbvdADvI...@giganews.com...
>
> On 7/15/15 12:18 PM, Maciej Woźniak wrote:
>> No, poor idiot. No thing in the world ever required and ever
>> will require your moronic "switching frames". One, observer
>> independent reference frame is enough for any reasonable
>> model.
>
>
> | See: http://www.phys.vt.edu/~takeuchi/relativity/notes/section15.html
>
> What for? To see you're not the only brainwashed moron in the
> world we inhabit?
>

Why do you think the physics community is brain washed, Maciej?

The original poster doesn't have a good grasp of inertial referece
frames. Perhaps you don't either. Going through this PDF may shed
some light on misconceptions.

Student understanding of time in special relativity: simultaneity
and reference frames
> http://arxiv.org/pdf/physics/0207109.pdf?origin=publication_detail

> This article reports on an investigation of student understanding of
> the concept of time in special relativity. A series of research tasks
> are discussed that illustrate, step-by-step, how student reasoning of
> fundamental concepts of relativity was probed. The results indicate
> that after standard instruction students at all academic levels have
> serious difficulties with the relativity of simultaneity and with the
> role of observers in inertial reference frames. Evidence is presented
> that suggests many students construct a conceptual framework in which
> the ideas of absolute simultaneity and the relativity of simultaneity
> harmoniously co-exist.

> Conclusions

> This investigation has identified widespread difficulties that
> students have with the definition of the time of an event and the
> role of intelligent observers. After instruction, more than 2/3 of
> physics undergraduates and 1/3 of graduate students in physics are
> unable to apply the construct of a reference frame in determining
> whether or not two events are simultaneous. Many students interpret
> the phrase “relativity of simultaneity” as implying that the
> simultaneity of events is determined by an observer on the basis of
> the reception of light signals. They often attribute the relativity
> of simultaneity to the difference in signal travel time for different
> observers. In this way, they reconcile statements of the relativity
> of simultaneity with a belief in absolute simultaneity and fail to
> confront the startling ideas of special relativity.

> Experienced instructors know that students often have trouble
> relating measurements made by observers in different reference
> frames. It is not surprising that students, even at advanced levels,
> do not fully understand the implications of the invariance of the
> speed of light. What is surprising is that most students apparently
> fail to recognize even the basic issues that are being addressed.
> Students at all levels have significant difficulties with the ideas
> that form the foundations of the concept of a reference frame. In
> particular, many students do not think of a reference frame as a
> system of observers that determine the same time for any given event.
> Such difficulties appear to impede not only their understanding of
> the relativity of simultaneity, but also their ability to apply
> correctly the Lorentz transformations.

> Special relativity offers instructors an opportunity to channel
> student interest in modern physics into a challenging intellectual
> experience. For most people, the implications of special relativity
> are in strong conflict with their intuition. For students to
> recognize the conflict and appreciate its resolution, they need to
> have a functional understanding of some very basic concepts.
> Formulating an appropriate measurement procedure for the time of an
> event involves recognizing the inherently local nature of
> measurement, applying a well-defined measurement procedure in a given
> reference frame, and understanding the relationship between
> measurements made by different observers. These ideas are crucial in
> contexts ranging from the rolling of a steel ball on a level track to
> the motion of objects in the vicinity of massive stars. This
> investigation documents prevalent modes of reasoning with these
> fundamental concepts as a first step toward making special relativity
> meaningful to students.




--

sci.physics is an unmoderated newsgroup dedicated
to the discussion of physics, news from the physics
community, and physics-related social issues.

[rotchm]

On Thursday, July 16, 2015 at 2:54:52 PM UTC-4, Julio Di Egidio wrote:
> On Thursday, July 16, 2015 at 7:45:57 PM UTC+1, rotchm wrote:
>
> > That setup is not new. It is a well know gedanken. The conclusion,
> is that the clocks (twins) reunite with the same values.
>
> For the last time, that is plain wrong:

So you say, and w/o any math to support your claim. Using only words is too imprecise; that's why we use "language of math", since it is succinct. IOW, SHOW THE MATH!

> if we had a third observer stationary with the origin, she and only
> she would see L and R's clocks in synch with each other.

SHE, AND EVERY ONE ELSE WILL CONCLUDE THAT both returning/coinciding twins (clocks) will indicate the same value. The math can be found in countless papers and documentations. READ UP!

> In fact, adding observers changes nothing: still the clocks would be late
> relative to her own clock,

So? We are not interested in comparing the values of her clock; we are interested in comparing the values of the returning and coinciding clocks.

> and still the twins would see *her* clock late relative to their own...

So? That is irrelevant. Moreover, refrain from using the word "see" since it has a different meaning than you think and indices confusions for newbies (as you).

>
> > Note that if you invoke accelerations
> <snip>
>
> I am not the one invoking accelerations...

Liar. On YOUR page
http://seprogrammo.blogspot.co.uk/2015/07/symmetric-twins-paradox.html

YOU invoke that word 3 times.

To further point out your confusions about SR, do you agree that SR says that 'time slows down' or a clock 'ticks slower' on a moving clock? If so, you are confused. SR doesnt say that. Moving clocks dont run slow according to SR. Great care and understanding are required to correctly comprehend such claims.

So, try again....

[rotchm]

On Thursday, July 16, 2015 at 6:57:00 PM UTC-4, Dono, wrote:

> > Note that if you invoke accelerations (of the twins) then
> > *you cant* apply SR from within their frames since their
> > frames are NON INERTIAL.
>
> This is, of course, false.

Again, you are wrong. I and even Tom pointed this out to you. Remember?

> SR deals with accelerated motion just fine.

Correct. Note that I did not say otherwise. Read correctly what I said.

So, the rest of your comment does not apply. Try again.

[Dono,]

On Thursday, July 16, 2015 at 8:17:17 PM UTC-7, rotchm wrote:
> On Thursday, July 16, 2015 at 6:57:00 PM UTC-4, Dono, wrote:
>
> > > Note that if you invoke accelerations (of the twins) then
> > > *you cant* apply SR from within their frames since their
> > > frames are NON INERTIAL.
> >
> > This is, of course, false.
>
> Again, you are wrong. I and even Tom pointed this out to you. Remember?

No, you are the only one who sustains such imbecilities, Stephane.

>
> > SR deals with accelerated motion just fine.
>
> Correct. Note that I did not say otherwise.

Sure you did, lying POS.

[rotchm]

Where in this thread did I say that again? Can you quote me on it? Of course you cant. You have shown your inability at simple math problems and now you show your inability to comprehend what you read. And of course, you remain ignorant and a liar. Good job, boy...

[Dono,]

On Thursday, July 16, 2015 at 9:11:37 PM UTC-7, rotchm wrote:
> On Thursday, July 16, 2015 at 11:36:23 PM UTC-4, Dono, wrote:
> > On Thursday, July 16, 2015 at 8:17:17 PM UTC-7, rotchm wrote:
>
> > > > SR deals with accelerated motion just fine.
> > >
> > > Correct. Note that I did not say otherwise.
> >
> > Sure you did, lying POS.
>
> Where in this thread did I say that again?

In THIS thread, lying POS.

> Can you quote me on it? Of course you cant.

Err, you are not only a liar, you are a stupid Liar:

https://groups.google.com/forum/?hl=en#!topic/sci.physics.relativity/7KgNzGFOYNI

[Dono,]

On Thursday, July 16, 2015 at 11:45:57 AM UTC-7, rotchm wrote:

> That setup is not new. It is a well know gedanken. The conclusion, is that the clocks (twins) reunite with the same values.
>
> Note that if you invoke accelerations (of the twins) then *you cant* apply SR from within their frames since their frames are NON INERTIAL.

Actually, contrary to your ignorant views, you can. You only need to know SR, something that you don't.

>you need GR and to specify which metric you which to use for each of their frames (and what definition of position and time too!).
>

No, you don't "need GR". You only need to know SR, something that you are obviously ignorant of.

[rotchm]

And there you go; Idiot dono the liar has not quoted. Providing a link is not to quote. Google kept a record of your lies...

[rotchm]

On Friday, July 17, 2015 at 9:03:56 AM UTC-4, Dono, wrote:
> On Thursday, July 16, 2015 at 11:45:57 AM UTC-7, rotchm wrote:

> > Note that if you invoke accelerations (of the twins) then *you cant*
> >apply SR from within their frames since their frames are NON INERTIAL.
>
> Actually, contrary to your ignorant views, you can. You only need to
> know SR, something that you don't.

You are just so confused... we all know that...

[Dono,]

You are so exposed, POS.

[underante]

aha! that makes a bit more sense now! good.

[Julio Di Egidio]

"Julio Di Egidio" <ju...@diegidio.name> wrote in message
news:mo5s70$vaf$1...@dont-email.me...

> Dear all,
>
> "In the context of special relativity, we present a twins experiment that
> is symmetric between the twins, so that a paradox appears inescapable, in
> the form of a violation of the principle of causality. [...] Bottom
> line: if special relativity is correct, it must be incomplete."
>
> <http://seprogrammo.blogspot.co.uk/2015/07/symmetric-twins-paradox.html>
>
> Feedback welcome,

Thanks for the feedback so far, that was quite useful.

I still have found no reason to think that (special) relativity is
necessarily wrong, it seems apparent to me that the twins paradox rather
calls for multiverses in some specific sense. On the other hand, it is now
clear that special relativity is completely misunderstood/mystified in the
mainstream at least, and already in its very basics. So, let us go back to
those basics (assume collinear motion, assume c=1):

1) The very principle of relativity establishes that there is no privileged
frame of reference. In particular, if you are moving relative to me, I am
moving relative to you in a perfectly symmetrical way, i.e. perfectly
symmetrical are all space-time relations in the two frames.

2) It is clear (and acknowledged) that length contraction is totally
symmetrical between two frames of reference moving relative to each other:

2.1) If you are moving relative to me at speed v > 0, and you carry a
meter stick, I will measure a (contracted) length of your meter stick, L =
sqrt(1-v^2) < 1. That is, a moving meter stick looks shorter to me than my
own meter stick.

2.2) If you are moving relative to me at speed v > 0, and I carry a meter
stick, you will measure a (contracted) length of my meter stick, L =
sqrt(1-v^2) < 1. That is, a stationary meter stick (moving relative to you)
looks shorter to you than your own meter stick.

2.3) Bottom line, if you and I are moving relative to each other, *at the
same time* your lengths will look shorter to me and my lengths will look
shorter to you.

3) Is is also clear (but usually not acknowledged) that time dilation is
totally symmetrical between two frames of reference moving relative to each
other:

3.1) If you are moving relative to me at speed v > 0, and you carry a
clock, I will measure a (dilated) unit of time on your clock, T =
1/sqrt(1-v^2) > 1. That is, a moving clock looks slower to me than my own
clock.

3.2) If you are moving relative to me at speed v > 0, and I carry a clock,
you will measure a (dilated) unit of time on my clock, T = 1/sqrt(1-v^2) >
1. That is, a stationary clock (moving relative to you) looks slower to you
than your own clock.

3.3) Bottom line, if you and I are moving relative to each other, *at the
same time* your clocks will look slower to me and my clocks will look slower
to you.

That is indeed already enough to establish the paradox: if you and I move
relative to each other, not only during motion each of us would see the
other's lengths contracted relative one's own (not reciprocal!), but also,
and permanently so (!), each of us would see the other's clocks late in time
relative to one's own (again, not reciprocal!).

On the other hand, note that most presentations of special relativity
problems are set up in terms of a "rest" frame vs. a "moving" frame: that is
not incorrect but it is only half of the coin, because, at the same time and
in a perfectly symmetrical way, the "rest" frame is moving relative to the
"moving" frame. As said, the relations involved are symmetrical, so indeed
solving one case implicitly solves the other (mathematically), but with
special relativity it becomes a mistake to forget that, physically, both
situations occur and they are in fact distinct!

Julio

[Dono,]

On Saturday, July 18, 2015 at 9:13:35 AM UTC-7, Julio Di Egidio wrote:
>
> On the other hand, note that most presentations of special relativity
> problems are set up in terms of a "rest" frame vs. a "moving" frame: that is
> not incorrect but it is only half of the coin, because, at the same time and
> in a perfectly symmetrical way, the "rest" frame is moving relative to the
> "moving" frame. As said, the relations involved are symmetrical, so indeed
> solving one case implicitly solves the other (mathematically), but with
> special relativity it becomes a mistake to forget that, physically, both
> situations occur and they are in fact distinct!
>
> Julio

You just demonstrated that you are an imbecile with zero understanding of relativity.

[hanson]

<ju...@diegidio.name> "Julio Di Egidio" wrote:
I still have found no reason to think that (special) relativity is
> necessarily wrong, it seems apparent to me that the twins paradox rather
> calls for multiverses in some specific sense. On the other hand, it is
> now clear that special relativity is completely misunderstood/mystified in

> the mainstream at least, and already in its very basics. <snip teh rest>
>
hanson wrote:
Never mind your additional hand waving "multi-versed" tripe, Julio.
Your math interpretation attemps got you into the classic
SR trap that you fell into "Inescapable ("symmetric)"... which
is hailed by all morons who are Einstein Dingleberriers, that
worship Albert's Sphincter, about which one poster even
cautioned you of, that you are "120 years too late". Pity.
>
So, Julio ,your belated historic heroic regurgitation efforts not
withstanding, you could have saved yourself a lot of anguish,
doubts and embarrassment had you considered first what....
>
.... hanson cited:
>
||| Edward Teller, the inventor of the H-Bomb, says:
<https://www.youtube.com/watch?v=vwiayZ3sH7U >
||| "Einstein didn't know what he was talking about..."
||| "...or he was lying, or both".
>
Teller was/is NOT alone with that notion. Other
luminaries said:
>
||| Prof. Carver A. Mead of Caltech (a student of Feynman),
||| "It is my firm belief that the 20th century will be
|||characterized in history as the dark ages of physics."
>
||| or F.A Hayek, Nobel laureate, who said: "In the future,
||| Humanity will see in our Epoch an Era of superstition, all
||| associated with the names of Marx, Freud and Einstein"
>
||| or John Beckman, an astronomy professor & Einstein disciple:
||| "The theory of relativity lives on. Is it a true picture of reality?
||| That is probably more a matter of FAITH than of proof."
>
Then there is also this about Relativity which shows that
it is a pitiful **Physics by hear-say** that needs FAITH
and BELIEF in "observers" which was condemned already
60+ years ago, 2 years before he died, when...
<http://tinyurl.com/Einstein-denied-his-SR-and-GR
in which Albert concluded that:
____ SR is short for STUPID RANT _____ & that
____ GR stands for GULLIBLE RECITAL _____
end cit
>
Ergo, SR&GR is only "observed" today by RETARDS
and deranged kikes who yearn to preserve Einstein's shit
as Jewish heritage... ahahahaha... like the cut&pasting
Jew Sam Wormey and his schizophrenic understudy,
Swine Glazier, the Face Shitter & Graveyard vandal does,
who also, in stereotypical Jew fashion trumped Einstein
with his "G=EMC^2" that Glazier stole off a farmer's barn.
>
Julio, you really wanna be a member of that sorry cabal?

.

[Gary Harnagel]

On Saturday, July 18, 2015 at 10:13:35 AM UTC-6, Julio Di Egidio wrote:
>
> ....

> That is indeed already enough to establish the paradox: if you and I move
> relative to each other, not only during motion each of us would see the
> other's lengths contracted relative one's own (not reciprocal!), but also,
> and permanently so (!), each of us would see the other's clocks late in time
> relative to one's own (again, not reciprocal!).
>
> On the other hand, note that most presentations of special relativity
> problems are set up in terms of a "rest" frame vs. a "moving" frame: that is
> not incorrect but it is only half of the coin, because, at the same time and
> in a perfectly symmetrical way, the "rest" frame is moving relative to the
> "moving" frame. As said, the relations involved are symmetrical, so indeed
> solving one case implicitly solves the other (mathematically), but with
> special relativity it becomes a mistake to forget that, physically, both
> situations occur and they are in fact distinct!
>
> Julio

A "rest" frame is called out simply for convenience. The "moving" frame
is NOT symmetrical because it actually consists of at least TWO frames.
THAT is the mistake you are making: forgetting that there aren't merely
two frames to consider, but three. If you want to know why that is so,
all you need to do is ask.

Gary

[paparios]

What you have not considered in your arguments, is that for performing the length and time measurements you have to applied a certain methodology.

For instance, to measure length in your own at rest frame of reference M, you as the observer need to use a ruler to measure the object length AT THE SAME TIME.

Similarly, to measure the length of a moving object with respect to frame M, you need now a number of observers, provided with Einstein synchronized clocks and rulers. Each observer has to note the time when the front of the object and the time the back of the object passed through his location. Comparing notes, then the team will be able to say: observer j located at coordinate x_j, observed the back of the passing object at time t_j, while observer k, located at coordinate x_k observed the front of the passing object also at time t_j. So the length of the moving object is L=x_k-x_j

Hence the measuring is clearly not symmetric. The length contraction will always require several observers to be measured.

[Maciej Woźniak]

Użytkownik "paparios" napisał w wiadomości grup
dyskusyjnych:eb853f12-ac62-4380...@googlegroups.com...

|For instance, to measure length in your own at rest frame of reference M,
you as the observer need to use a ruler to measure the object length AT THE
SAME TIME.
|Similarly, to measure the length of a moving object with respect to frame
M, you need now a number of observers, provided with Einstein synchronized
clocks and rulers. Each observer has to note the time

Remember, however, that physicist's tales of observer are
pure fabrication. They never had anything in common
with reality and real observers.

[Sylvia Else]

On 19/07/2015 2:11 AM, Julio Di Egidio wrote:

> 3) Is is also clear (but usually not acknowledged) that time dilation is
> totally symmetrical between two frames of reference moving relative to
> each other:
>
> 3.1) If you are moving relative to me at speed v > 0, and you carry a
> clock, I will measure a (dilated) unit of time on your clock, T =
> 1/sqrt(1-v^2) > 1. That is, a moving clock looks slower to me than my
> own clock.
>
> 3.2) If you are moving relative to me at speed v > 0, and I carry a
> clock, you will measure a (dilated) unit of time on my clock, T =
> 1/sqrt(1-v^2) > 1. That is, a stationary clock (moving relative to you)
> looks slower to you than your own clock.
>
> 3.3) Bottom line, if you and I are moving relative to each other, *at
> the same time* your clocks will look slower to me and my clocks will
> look slower to you.
>
> That is indeed already enough to establish the paradox: if you and I
> move relative to each other, not only during motion each of us would see
> the other's lengths contracted relative one's own (not reciprocal!), but
> also, and permanently so (!), each of us would see the other's clocks
> late in time relative to one's own (again, not reciprocal!).
>

If that did indeed establish the existence of a paradox, do you really
think that it would have been overlooked for the last hundred years,
waiting to be discovered by you?

Such hubris.

Sylvia.

[Koobee Wublee]

> > Let's assign the equations:
> >
> > 1) dt12 = (dt32 - v31 dx32 / c^2) / sqrt(1 - v31^2 / c^2)
> > 2) dx12 = (dx32 - v31 dt32) / sqrt(1 - v31^2 / c^2)
> > 3) dy12 = dy32
> > 4) dz12 = dz32
> >
> > Square each equations above, and subtract the sum of equations 2 to 4
> > squared from equation 1 squared:
>
> > ** equ(1)^2 - equ(2)^2 - equ(3)^2 - equ(4)^2
>
> > Or
>
> > ** c^2 dt12^2 - dx12^2 - dy^12 - dz12^2 = c^2 dt32^2 - dx32^2 - dy^32 - dz32^2
>
> > Or
>
> > ** c^2 dt12^2 - v12^2 dt12^2 = c^2 dt32^2 - v32^2 dt32^2
>
> > Or
>
> > ** dt12^2 (1 - v12^2 / c^2) = c^2 dt32^2 (1 - v32^2 / c^2)
>

> > Where
> >
> > ** v12^2 dt12^2 = (dx12)^2 + (dy12)^2 + (dz12)^2
> > ** v32^2 dt32^2 = (dx32)^2 + (dy32)^2 + (dz32)^2
> >
> > Notice v13 and v31 vanish. This is exactly how Minkowski was able
> > to derive spacetime from the Lorentz transform. Although Larmor's
> > transform is mathematically similar but drastically different in
> > extreme boundaries, spacetime derived from Larmor's transform is
> > mathematically no different from the spacetime derived from the
> > Lorentz transform. Larmor's transform is an antithesis to the
> > Lorentz transform. Larmor's transform demands the very existence
> > of the Aether. <shrug>
>
> aha! that makes a bit more sense now! good.

Yes, with Koobee Wublee's presentation of the mathematics above no Einstein dingleberries are able to get away with their mathemaGic shit. From this, Koobee Wublee is able to pinpoint where Paul Andersen has play out its mathemaGic trick in formulating that JAVA stuff. <shrug>

That conclusion is that the math of SR is nothing but mathemaGics, and SR is nothing but a religion where the worshippers of SR worship their god Einstein the nitwit, the plagiarist, and the liar. This cult is no better off than the Moonies. <shrug>

[Koobee Wublee]

On Saturday, July 18, 2015 at 10:03:29 PM UTC-7, Sylvia Else wrote:

> If that did indeed establish the existence of a paradox, do you really
> think that it would have been overlooked for the last hundred years,
> waiting to be discovered by you?

Right, speaking just like any of these religious nuts giving lip services to how great their religions are just because their religions have scammed and flourished for quite a fvcking long time. <shrug>

> Such hubris.

Cheap whore promoting her religion. <shrug>

[rotchm]

This, coming from the idiot dono who maintains that two simultaneous events in one iframe remain simul in another iframe, if the events are caused by the ends of a horizontal falling rod! LOL. Idiot dono, why dont you just forget about physics and try for garbage collecting.

[Dono,]

On Sunday, July 19, 2015 at 7:00:01 AM UTC-7, rotchm wrote:
> On Saturday, July 18, 2015 at 12:33:24 PM UTC-4, Dono, wrote:
> > On Saturday, July 18, 2015 at 9:13:35 AM UTC-7, Julio Di Egidio wrote:
>
> > > Julio
> >
> > You just demonstrated that you are an imbecile with zero
> > understanding of relativity.
>
> This, coming from the idiot dono who maintains that two simultaneous events in one iframe remain simul in another iframe,

You countinue to lie, POS.

[rotchm]

On Sunday, July 19, 2015 at 10:06:40 AM UTC-4, Dono, wrote:

> > This, coming from the idiot dono who maintains that two
> >simultaneous events in one iframe remain simul in another iframe,

> > if the events are caused by the ends of a horizontal falling rod
>

> You countinue to lie, POS.

From idiot dono,
" The short answer is that the presence of the gravitational field
in the exercise makes it (the exercise) unsuitable for application
of SR. You can't solve this exercise in the context of SR..."

Even though there were no mention, nor no need of a gravitational field in the problem, idiot dono maintains his stance till this day. Google kept a record!

Want the links to the numerous threads where you maintain your stance? We can ervive them if you want, or start a new one...

[Dono,]

On Sunday, July 19, 2015 at 7:44:39 AM UTC-7, rotchm wrote:
> On Sunday, July 19, 2015 at 10:06:40 AM UTC-4, Dono, wrote:
>
> > > This, coming from the idiot dono who maintains that two
> > >simultaneous events in one iframe remain simul in another iframe,
> > > if the events are caused by the ends of a horizontal falling rod
> >
> > You countinue to lie, POS.
>
> From idiot dono,
> " The short answer is that the presence of the gravitational field
> in the exercise makes it (the exercise) unsuitable for application
> of SR. You can't solve this exercise in the context of SR..."
>
> Even though there were no mention, nor no need of a gravitational field in the problem,

Stephane,

You are a poser and a pretender, live with it.

[Sam Wormley]

On 7/15/15 8:53 AM, Julio Di Egidio wrote:
> "In the context of special relativity, we present a twins experiment
> that is symmetric between the twins, so that a paradox appears
> inescapable, in the form of a violation of the principle of causality.
> [...] Bottom line: if special relativity is correct, it must be
> incomplete."

Here is an accurate analysis of the twin paradox for
symmetrically traveling twins


Solution
> http://www.phys.vt.edu/~takeuchi/relativity/practice/TwinParadox.gif
> http://www.phys.vt.edu/~takeuchi/relativity/practice/solution18.html

> As Alice travels from O to A on the outbound portion of her trip, she
> observes the time in Beth's spaceship to pass from O to I, which is
> shorter than the time from O to A in Alice's frame. During the
> inbound portion of her trip from A to C, Alice observes the time in
> Beth's spaceship to pass from E to C, which is again shorter than the
> time from A to C in Alice's frame. However, when Alice turns around
> at A to switch inertial frames, the point along Beth's worldline
> which is simultaneous with A jumps forward from I to E, which cancels
> out the time dilation effect.

> Similarly, as Beth travels from O to B on the outbound portion of her
> trip, she observes the time in Alice's spaceship to pass from O to H,
> which is shorter than the time from O to B in Beth's frame. During
> the inbound portion of her trip from B to C, Beth observes the time
> in Alice's spaceship to pass from D to C, which is again shorter than
> the time from B to C in Beth's frame. However, when Beth turns around
> at B to switch inertial frames, the point along Alice's worldline
> which is simultaneous with B jumps forward from H to D, which cancels
> out the time dilation effect.

> Both Alice and Beth observe the time in the other spaceship to be
> flowing slower in the outbound and inbound parts of their trips, but
> because of the "jump forward" effect when they turn around, they will
> be of the same age when they meet at C.

[Koobee Wublee]

On Sunday, July 19, 2015 at 10:22:12 AM UTC-7, Sam Wormley wrote:
> On 7/15/15 8:53 AM, Julio Di Egidio wrote:

> > "In the context of special relativity, we present a twins experiment
> > that is symmetric between the twins, so that a paradox appears
> > inescapable, in the form of a violation of the principle of causality.
> > [...] Bottom line: if special relativity is correct, it must be
> > incomplete."
>
> Here is an accurate analysis of the twin paradox for
> symmetrically traveling twins
>

> > http://www.phys.vt.edu/~takeuchi/relativity/practice/TwinParadox.gif
> > http://www.phys.vt.edu/~takeuchi/relativity/practice/solution18.html
>
> > As Alice travels from O to A on the outbound portion of her trip, she
> > observes the time in Beth's spaceship to pass from O to I, which is
> > shorter than the time from O to A in Alice's frame. During the
> > inbound portion of her trip from A to C, Alice observes the time in
> > Beth's spaceship to pass from E to C, which is again shorter than the
> > time from A to C in Alice's frame. However, when Alice turns around
> > at A to switch inertial frames, the point along Beth's worldline
> > which is simultaneous with A jumps forward from I to E, which cancels
> > out the time dilation effect.
>
> > Similarly, as Beth travels from O to B on the outbound portion of her
> > trip, she observes the time in Alice's spaceship to pass from O to H,
> > which is shorter than the time from O to B in Beth's frame. During
> > the inbound portion of her trip from B to C, Beth observes the time
> > in Alice's spaceship to pass from D to C, which is again shorter than
> > the time from B to C in Beth's frame. However, when Beth turns around
> > at B to switch inertial frames, the point along Alice's worldline
> > which is simultaneous with B jumps forward from H to D, which cancels
> > out the time dilation effect.
>
> > Both Alice and Beth observe the time in the other spaceship to be
> > flowing slower in the outbound and inbound parts of their trips, but
> > because of the "jump forward" effect when they turn around, they will
> > be of the same age when they meet at C.

That's Alice and Beth in Wonderland with plenty of handwaving by Takeuchi. No math, no logic, more bullshit. <shrug>

[Paul B. Andersen]

https://paulba.no/pdf/Mutual_time_dilation.pdf
https://paulba.no/pdf/TwinsByMetric.pdf
https://paulba.no/pdf/TwinsByDoppler.pdf
https://paulba.no/twins.html

--
Paul

https://paulba.no/