Gary's "Solution" to the Issue of Causality Violation as a Result of Tachyonic Signaling Is Not Viable

[Prokaryotic Capase Homolog]

Gary's proposed solution to the problem of causality violation resulting
from superluminal messaging implies that reality changes with observer
motion, and is hence in violent conflict with the Principle of Relativity.

Minkowski diagrams are usually presented with frames in "standard
configuration" with the lab frame stationary. The forward Lorentz
transformation is used to map the coordinates of events in the lab frame
S to their coordinates in the primed frame S'.

For the purpose of this demonstration, we will set the primed frame S' as
the stationary frame, with the lab frame S in different states of motion.
To simplify the diagrams, we will not draw the coordinates of the lab frame,
which of course will always be orthogonal.

https://drive.google.com/file/d/1mZJcqaV2KieXFNU5iWHCsVtDK21HOLWE/view?usp=sharing

We begin by considering two objects C and D in the primed frame a distance
L apart. In the left illustration, we show how at time t' = 0, D sends an
instantaneous signal to C. In the illustration on the right, we present the
same scenario but also including an infinite number of background events.
The black dot represents the receipt of the signal by C.

In the following triptych of diagrams, we send the lab observer moving to
the right and then to the left, using the inverse Lorentz transform to map
events from S' to the lab frame. Note how, although the time and space
coordinates of the events as observed from lab frame S are smoothly
distorted, their topological relationships are always maintained.

Gary objects to the diagram on the right, since the arrow is downwards
sloping in the lab frame, meaning that the signal is going back in time. He
proposes that the signal by cannot arrive any earlier at C than vL/c^2,
thus preventing the possibility of causal loop formation.

Gary's "solution" is not viable. Look carefully at the events surrounding
the receipt of the tachyonic signal. They have changed as a result of
observer motion! The event representing the receipt of the tachyonic signal
by C has been displaced from its original context. Quite literally, the
fabric of spacetime has been ripped apart.

No reasonable model of reality can permit such a thing to happen.

[Gary Harnagel]

On Saturday, October 3, 2020 at 1:30:37 AM UTC-6, prokaryotic.c...@gmail.com wrote:
>
> Gary's proposed solution to the problem of causality violation resulting
> from superluminal messaging implies that reality changes with observer
> motion, and is hence in violent conflict with the Principle of Relativity.

How does DIRECT tachyon communication between relatively-moving observers
conflict with the PoR?

It doesn't, of course. So it's fair to ask why any other method would. It's also fair
to ask whether some "sleight-of-hand" is involved in any other purported method.

It's not clear what you're arguing here. Are you claiming causality is violated,
or that some hypothetical construct called "spacetime" is actually a real
thing ? Perhaps we should discuss DIRECT tachyon communication first.
You APPEAR to have addressed this in your "triptych" but it lacks the actual
"hand-off" of information:

And how does one of these "background events" affect what happens in a lab?
We seem to have different ideas of what constitutes "causality violation." I
see it as a signal actually being generated in the present and received in the past.

[Prokaryotic Capase Homolog]

In your model, the CONTEXT of events surrounding the receipt of a tachyon signal
by C changes with shifts in the observer frame.

Look at the events immediately surrounding the black dot representing the receipt
of the tachyon signal. These are the events that would be immediately affected
by receipt of the tachyon signal. In your theory, these would be different for each
observer. Alterations in these immediately affected events would change the entire
future history from receipt of the signal.

In other words, according to your theory, every observer will witness a different
universe unfolding from receipt of the tachyon signal.

Your theory is INSANE.

[Prokaryotic Capase Homolog]

On Saturday, October 3, 2020 at 5:58:54 PM UTC-5, Prokaryotic Capase Homolog wrote:

> In your model, the CONTEXT of events surrounding the receipt of a tachyon signal
> by C changes with shifts in the observer frame.
>
> Look at the events immediately surrounding the black dot representing the receipt
> of the tachyon signal. These are the events that would be immediately affected
> by receipt of the tachyon signal. In your theory, these would be different for each
> observer. Alterations in these immediately affected events would change the entire
> future history from receipt of the signal.
>
> In other words, according to your theory, every observer will witness a different
> universe unfolding from receipt of the tachyon signal.
>
> Your theory is INSANE.

I've appended some additional material to my illustration:
https://drive.google.com/file/d/1mZJcqaV2KieXFNU5iWHCsVtDK21HOLWE/view?usp=sharing

Since in your theory, the events surrounding the receipt of the tachyonic signal
vary according to observer motion, the ENTIRE FUTURE from the moment of receipt of
the signal will be observer-dependent. In the above, I illustrate the future
light-cones from receipt of the signal for different observers moving at different
speeds relative to the primed frame. The events encompassed within these future
light-cones are not the same.

[Dindu Nuffin]

Prokaryotic Capase Homolog wrote:

> Since in your theory, the events surrounding the receipt of the
> tachyonic signal vary according to observer motion, the ENTIRE FUTURE
> from the moment of receipt of the signal will be observer-dependent. In
> the above,
> I illustrate the future light-cones from receipt of the signal for
> different observers moving at different speeds relative to the primed
> frame. The events encompassed within these future light-cones are not
> the same.

not true. This emphasise you don't know how the faux rtPCR tests are
working. It takes a chunk of a molecule and amplify it. After a say 20
times, you have 2²⁰ = about 1 million, which may or not be seen as proof
for the real existence of that samples, due to noise etc (copy of a
copy). But these proper mafia governments are amplifying it over 40
times, thus the positive goes towards 100%. Now, before the tronald drumpf
militarized mandatory powerful by force vaccination, using the same
tests, these deep criminals will lower the number of runs of the
amplifications to a say, 10, or 8 -> 256, barely detectable "proof" for
the existence of a real fake "corona". Hence, you have to be vaccinated.
Everybody got it now? You idiots.

[Gary Harnagel]

On Sunday, October 4, 2020 at 4:38:04 AM UTC-6, prokaryotic.c...@gmail.com wrote:
>
> On Saturday, October 3, 2020 at 5:58:54 PM UTC-5, Prokaryotic Capase Homolog wrote:
> >
> > In your model, the CONTEXT of events surrounding the receipt of a tachyon signal
> > by C changes with shifts in the observer frame.

Actually, this is not so. I stated in the previous thread that I was wrong about that,
so that horse is dead.

> Since in your theory, the events surrounding the receipt of the tachyonic signal
> vary according to observer motion, the ENTIRE FUTURE from the moment of receipt of
> the signal will be observer-dependent. In the above, I illustrate the future
> light-cones from receipt of the signal for different observers moving at different
> speeds relative to the primed frame. The events encompassed within these future
> light-cones are not the same.

Which is beating a path to nowhere. But let's talk about "spacetime." What IS it?
John Norton has a great description of it:

"We build a spacetime by taking instantaneous snapshots of space at successive
instants of time and stacking them up."

http://www.pitt.edu/~jdnorton/teaching/HPS_0410/chapters/spacetime/

This is EXACTLY what a laboratory scenario does, and it relegates "spacetime" to a
concept rather than a "fabric" that can be "ripped apart." In an instantaneous snapshot
of space, there is no future and no past. In Figure 4-4:

https://en.wikipedia.org/wiki/Special_relativity#Graphical_representation_of_the_Lorentz_transformation

the possibility of D at (L,vL/c²) sending tachyons to C at (0,0) is presumed, but the
Norton/lab instantaneous view would have C at (v²L/c², vL/c²) when B initiates the
message and passes it to D. But A is at (0,vL/c²) and C is not adjacent to A so no
"hand-off" is possible.

In order to have a hand-off, another moving observer, P, must be to the left of C which
is adjacent to A at t = vL/c² (0,vL/c²).

tP' = g(vL/c² - 0), so u' = 0 - gL)/(gvL/c² - 0) = -c²/v.

This event (0,vL/c²) occurs at the same place in both frames, [-v²L/c²,gvL/c²] in S', so
the fictitious spacetime isn't "ripped apart" even if it physically existed. And causality
is preserved, too. And the issue becomes consistent with the direct communication
scenario between moving observers.

[Prokaryotic Capase Homolog]

On Sunday, October 4, 2020 at 10:02:39 AM UTC-5, Gary Harnagel wrote:
> On Sunday, October 4, 2020 at 4:38:04 AM UTC-6, prokaryotic.c...@gmail.com wrote:
> >
> > On Saturday, October 3, 2020 at 5:58:54 PM UTC-5, Prokaryotic Capase Homolog wrote:
> > >
> > > In your model, the CONTEXT of events surrounding the receipt of a tachyon signal
> > > by C changes with shifts in the observer frame.
>
> Actually, this is not so. I stated in the previous thread that I was wrong about that,
> so that horse is dead.
>
> > Since in your theory, the events surrounding the receipt of the tachyonic signal
> > vary according to observer motion, the ENTIRE FUTURE from the moment of receipt of
> > the signal will be observer-dependent. In the above, I illustrate the future
> > light-cones from receipt of the signal for different observers moving at different
> > speeds relative to the primed frame. The events encompassed within these future
> > light-cones are not the same.
>
> Which is beating a path to nowhere. But let's talk about "spacetime." What IS it?
> John Norton has a great description of it:

NO, we will not talk about spacetime. In this thread,
WE WILL NOT BE DISTRACTED FROM THIS CENTRAL MISCONCEPTION OF YOURS.

In the following exchange, https://tinyurl.com/y2d7joqd, I had written:
| As near as I can gather, then, you believe in the following:
| https://drive.google.com/file/d/1gipoP6PFcy0oqDvjAciWvAbvh5HQHEfZ/view?usp=sharing
To which you responded:
| You have everything right except you cunningly left out the fact that although
| D can't SEND tachyons to Event c in the third diagram, they will arrive at
| Event e @ (vL/c², 0).
| Sure, lab observers can SEE Event c at t = 0 in the lab frame., but that's
| not where the tachyons will go.

Later, you wrote in https://tinyurl.com/y26rhf5w:
| But if they go to (0,vL/c²) in the lab frame, they go there in all frames.

1) You do not like arrows going backwards in time in the lab frame.
2) In the rightmost set of figures in https://tinyurl.com/yy5tugup, instead of
drawing the arrow from Event d to Event c, which is to say, from (L,0) to (0,0)
in primed frame coordinates, you would have the arrow going somewhere else.

Instead of the arrow leading from (L,0) to (0,0) in primed frame coordinates,
where do you want the endpoint of the arrow to go (in PRIMED frame coordinates)?

If your answer involves use of "v", then physics in the primed frame depends on
the relative motion of the lab frame and the primed frame.

[SNIP a bunch of confused arguments intended to distract]

[Hale]

Prokaryotic Capase Homolog wrote:

> On Sunday, October 4, 2020 at 10:02:39 AM UTC-5, Gary Harnagel wrote:
>> Which is beating a path to nowhere. But let's talk about "spacetime."
>> What IS it? John Norton has a great description of it:
>
> NO, we will not talk about spacetime. In this thread,
> WE WILL NOT BE DISTRACTED FROM THIS CENTRAL MISCONCEPTION OF YOURS.

> [SNIP a bunch of confused arguments intended to distract]

All yours.

[Gary Harnagel]

On Sunday, October 4, 2020 at 11:57:31 PM UTC-6, prokaryotic.c...@gmail.com wrote:
>
> On Sunday, October 4, 2020 at 10:02:39 AM UTC-5, Gary Harnagel wrote:
> >
> > On Sunday, October 4, 2020 at 4:38:04 AM UTC-6, prokaryotic.c...@gmail.com wrote:
> > >
> > > Since in your theory, the events surrounding the receipt of the tachyonic signal
> > > vary according to observer motion, the ENTIRE FUTURE from the moment of receipt of
> > > the signal will be observer-dependent. In the above, I illustrate the future
> > > light-cones from receipt of the signal for different observers moving at different
> > > speeds relative to the primed frame. The events encompassed within these future
> > > light-cones are not the same.
> >
> > Which is beating a path to nowhere. But let's talk about "spacetime." What IS it?
> > John Norton has a great description of it:
>
> NO, we will not talk about spacetime. In this thread,
> WE WILL NOT BE DISTRACTED FROM THIS CENTRAL MISCONCEPTION OF YOURS.

YOU are the one claiming spacetime is shredded by what you SUPPOSE is
my position, so you are being completely unfair with that position.

> In the following exchange, https://tinyurl.com/y2d7joqd, I had written:
> | As near as I can gather, then, you believe in the following:
> | https://drive.google.com/file/d/1gipoP6PFcy0oqDvjAciWvAbvh5HQHEfZ/view?usp=sharing
> To which you responded:
> | You have everything right except you cunningly left out the fact that although
> | D can't SEND tachyons to Event c in the third diagram, they will arrive at
> | Event e @ (vL/c², 0).
> | Sure, lab observers can SEE Event c at t = 0 in the lab frame., but that's
> | not where the tachyons will go.
>
> Later, you wrote in https://tinyurl.com/y26rhf5w:
> | But if they go to (0,vL/c²) in the lab frame, they go there in all frames.
>
> 1) You do not like arrows going backwards in time in the lab frame.
> 2) In the rightmost set of figures in https://tinyurl.com/yy5tugup, instead of
> drawing the arrow from Event d to Event c, which is to say, from (L,0) to (0,0)
> in primed frame coordinates, you would have the arrow going somewhere else.
>
> Instead of the arrow leading from (L,0) to (0,0) in primed frame coordinates,
> where do you want the endpoint of the arrow to go (in PRIMED frame coordinates)?
>
> If your answer involves use of "v", then physics in the primed frame depends on
> the relative motion of the lab frame and the primed frame.
>
> [SNIP a bunch of confused arguments intended to distract]

By absolutely refusing to consider what "spacetime" REALLY is, you will NEVER be
able to understand why you are dead wrong:

http://www.pitt.edu/~jdnorton/teaching/HPS_0410/chapters/spacetime/

"We build a spacetime by taking instantaneous snapshots of space at successive
instants of time and stacking them up."

Thus the lab frame is identical to the "instantaneous snapshots of space" which
describes where objects ARE at that instant and not where they were. This has
been my view of the Minkowski diagram from the start, as opposed to YOUR view
(and that of the conventional view, too).

And, no, this isn't your hyperbole: "confused arguments intended to distract."
It's at the crux of our disagreement. And the stuff that you deleted is cogent
and clear. Perhaps you should create a figure representing the details.

BTW, I appreciate your adversarial position because it makes me become aware
of the weak points of MY position.

“I never learned from a man that agreed with me.” – Robert A. Heinlein

Your comments about "shredding spacetime" put the final capper on why point P
(to the left of C) is the correct endpoint of the signal from D to C. I had suggested
it way back in the first version of my paper, but it didn't have a robust foundation.
The lab frame/instantaneous snapshot idea to build up spacetime combined with
the sanctity of events leads to the correct solution to tachyon causality.

[Prokaryotic Capase Homolog]

What are the coordinates of Point P, expressed in primed coordinates?

[Gary Harnagel]

At what time? At t = 0, they are (-v²L/c²,0) in S, [-gv²L/c²,g(v²/c²)vL/c²] in S'.

At t = vL/c², they are (0,vL/c²) in S, [-gv²L/c², gvL/c²] in S'.

[Prokaryotic Capase Homolog]

So expressed in primed coordinates, the endpoint P of the signal from D to C, which
are both "in" frame S', depends on v.

What you are saying is that the laws of physics in the primed frame depend on
the relative velocity of the primed and unprimed frames.

You therefore deny the principle of relativity.

[Gary Harnagel]

Oh, come off it! The hand-off points are DIFFERENT for different parameters, because
THAT is a different PROBLEM. Velocity between frames is a PARAMETER. This is
simple algebra, simple physics. You seem to be squirming around trying to find any
vacuous reason to remain in denial of the fact that tachyons do indeed obey physical
law.

[coea...@gmail.com]

On Monday, October 5, 2020 at 4:14:34 PM UTC-7, Gary Harnagel wrote:
> Oh, come off it!

According to you, A can transmit a message to B at speed 10c in terms of their mutual rest frame, and B can immediately transmit the message to D at speed 1c as they cross paths (with mutual speed c/2), and D can immediately transmit the message to C at speed 10c in terms of their mutual rest frame, and C can immediately transmit the message to A at speed 1c as they cross paths. But this implies that the message is received by A from C prior to being transmitted by A, which entails a causal loop.

[Prokaryotic Capase Homolog]

I have no "hand-off" points in my diagram. You've got Figure 4-4 on the brain.

I ask, very simply, that if a near-instantaneous tachyon signal is emitted by D at
point (x',t') = (L,0), at what point will the signal be received by C, expressed
in primed coordinates.

And please specify whether you are using (x',t') or (t',x') convention. Since your
previous answer made NO SENSE either way, I found it impossible to plot.

If "v" shows up anywhere in your answer, it means that you deny the principle of
relativity.

[Gary Harnagel]

On Monday, October 5, 2020 at 6:57:51 PM UTC-6, coea...@gmail.com wrote:
>
> On Monday, October 5, 2020 at 4:14:34 PM UTC-7, Gary Harnagel wrote:
>
> > Oh, come off it!
>
> According to you, A can transmit a message to B at speed 10c in terms of their mutual rest frame,
> and B can immediately transmit the message to D at speed 1c as they cross paths (with mutual
> speed c/2), and D can immediately transmit the message to C at speed 10c in terms of their mutual
> rest frame,

Do I? Are you SURE?

> and C can immediately transmit the message to A at speed 1c as they cross paths.

Can he? Are you SURE?

> But this implies that the message is received by A from C prior to being transmitted
> by A, which entails a causal loop.

All you've shown is that you completely misunderstand the theory I'm proposing.
Perhaps you should go back and reread my post that PCH tore the heart out of.

[Gary Harnagel]

No, that's NOT what you asked. You asked for the coordinates of point P in the
S' frame. Which means you WERE talking about the problem of Fig. 4-4.

> And please specify whether you are using (x',t') or (t',x') convention. Since your
> previous answer made NO SENSE either way, I found it impossible to plot.
>
> If "v" shows up anywhere in your answer, it means that you deny the principle of
> relativity.

So if L shows up anywhere, it means that denies PoR, too? Don't you even realize
L is a parameter, too, just like v? You seem to have gone completely bonkers.
You need to take some deep breaths and try to regather your wits about you.

I know, when one's cherished beliefs come crashing down, it can be quite
traumatic, but I'm sure you can overcome that river in northeast Africa ;-)

[coea...@gmail.com]

On Monday, October 5, 2020 at 8:02:29 PM UTC-7, Gary Harnagel wrote:
> > According to you, A can transmit a message to B at speed 10c in
> > terms of their mutual rest frame, and B can immediately transmit
> > the message to D at speed 1c as they cross paths (with mutual
> > speed c/2), and D can immediately transmit the message to C at
> > speed 10c in terms of their mutual rest frame,
>
> Do I? Are you SURE?

Your question doesn't parse. If you meant to ask "Have I (Gary) really stipulated to those things?", the answer is yes, you most certainly have. Remember, the context is special relativity, which entails the principle of relativity, Lorentz invariance, the ability to send signals at the speed of light, and so on. You have stipulated to all these things, because that is the context of the assertion you are challenging. To these things you add another claim, namely that for two relatively resting objects a signal at 10c can be sent from one to the other in terms of their mutual rest frame. The combination of the stipulated context and your single added claim leads to closed causal loops (see above), which proves that your added claim (superluminal signaling) is false.

> and C can immediately transmit the message to A at speed 1c as
> they cross paths.
>
> Can he? Are you SURE?

Again, the ability of subluminal objects to send light signals to each other is part of the context of special relativity, to which you have stipulated. You may believe personally that light signals are impossible, but any such absurd belief is not relevant to this discussion. The context here is special relativity and rationality.

> > But this implies that the message is received by A from C prior to
> > being transmitted by A, which entails a causal loop.
>
> All you've shown is that you completely misunderstand the theory
> I'm proposing.

That isn't a substantive argument. You've been presented with the simple and irrefutable proof that, in the context of special relativity, any ability to send superluminal signals would imply the ability to create closed causal loops. If you had any substantive reply, you would presumably have given it. Case closed.

[Prokaryotic Capase Homolog]

Re-read my question. I specifically referred to THIS IMAGE:
https://tinyurl.com/yy5tugup

> > And please specify whether you are using (x',t') or (t',x') convention. Since your
> > previous answer made NO SENSE either way, I found it impossible to plot.
> >
> > If "v" shows up anywhere in your answer, it means that you deny the principle of
> > relativity.
>
> So if L shows up anywhere, it means that denies PoR, too? Don't you even realize
> L is a parameter, too, just like v? You seem to have gone completely bonkers.
> You need to take some deep breaths and try to regather your wits about you.

Don't be silly. L is the proper distance between C and D.

> I know, when one's cherished beliefs come crashing down, it can be quite
> traumatic, but I'm sure you can overcome that river in northeast Africa ;-)

Speaking for yourself?

So what -IS- your answer? If a near-instantaneous tachyon signal is emitted by D at
point (x',t') = (L,0), what are the coordinates of the event representing the
receipt of the signal by C, expressed in primed coordinates. And as I requested,
please specify whether you use the (x',t') or (t',x') convention, because your
answers so far haven't made any sense either way.

[Gary Harnagel]

On Monday, October 5, 2020 at 9:26:18 PM UTC-6, coea...@gmail.com wrote:
>
> On Monday, October 5, 2020 at 8:02:29 PM UTC-7, Gary Harnagel wrote:
> >
> > > According to you, A can transmit a message to B at speed 10c in
> > > terms of their mutual rest frame, and B can immediately transmit
> > > the message to D at speed 1c as they cross paths (with mutual
> > > speed c/2), and D can immediately transmit the message to C at
> > > speed 10c in terms of their mutual rest frame,
> >
> > Do I? Are you SURE?
>
> Your question doesn't parse.

So now you're reduced to picking nits.

> If you meant to ask "Have I (Gary) really stipulated to those things?", the answer
> is yes, you most certainly have.

And you are wrong at the very least (maybe lying at most).

I speak in algebraic terms, not numerically.

> Remember, the context is special relativity, which entails the principle of relativity,
> Lorentz invariance, the ability to send signals at the speed of light, and so on.
> You have stipulated to all these things, because that is the context of the assertion
> you are challenging. To these things you add another claim, namely that for two
> relatively resting objects a signal at 10c can be sent from one to the other in terms
> of their mutual rest frame.

I HAVE stipulated that in principle IF tachyons exist. I believe they do, so carry on:

> The combination of the stipulated context and your single added claim leads to
> closed causal loops (see above), which proves that your added claim (superluminal
> signaling) is false.

I've gone to great lengths to demonstrate that tachyons don't violate causality, or
as you say, "create causal loops." Thus your conclusion is nonsense.

> > and C can immediately transmit the message to A at speed 1c as
> > they cross paths.
> >
> > Can he? Are you SURE?
>

> Again, [Blah, blah, blah. Repeated falsehoods deleted]

> > > But this implies that the message is received by A from C prior to
> > > being transmitted by A, which entails a causal loop.
> >
> > All you've shown is that you completely misunderstand the theory
> > I'm proposing.
>
> That isn't a substantive argument.

Actually, it is ... IF you've read and UNDERSTOOD what I proposed as a
solution to Figure 4-4. Obviously, you haven't.

>You've been presented with the simple and irrefutable proof that, in
> the context of special relativity, any ability to send superluminal signals
> would imply the ability to create closed causal loops.

And I've presented irrefutable proof that tachyons don't create your so-called

"causal loops."

> If you had any substantive reply, you would presumably have given it. Case closed.

The only thing "closed" around here is your mind. Stop babbling baloney and go
back and read my "substantive reply" about Fig 4-4.

[Gary Harnagel]

I don't care about that image.

> > > And please specify whether you are using (x',t') or (t',x') convention. Since your
> > > previous answer made NO SENSE either way, I found it impossible to plot.
> > >
> > > If "v" shows up anywhere in your answer, it means that you deny the principle of
> > > relativity.
> >
> > So if L shows up anywhere, it means that denies PoR, too? Don't you even realize
> > L is a parameter, too, just like v? You seem to have gone completely bonkers.
> > You need to take some deep breaths and try to regather your wits about you.
>
> Don't be silly. L is the proper distance between C and D.

OF COURSE IT IS. AND v IS THE RELATIVE VELOCITY IN A PARTICULAR EXPERIMENT.

> > I know, when one's cherished beliefs come crashing down, it can be quite
> > traumatic, but I'm sure you can overcome that river in northeast Africa ;-)
>
> Speaking for yourself?

I'm not the one in de Nile, mon ami. I provided a solution to your Figure 4-4
that allows superluminal speeds and doesn't violate causality and you REFUSE
to address it because of ... what? vanity?

> So what -IS- your answer? If a near-instantaneous tachyon signal is emitted by D at
> point (x',t') = (L,0), what are the coordinates of the event representing the
> receipt of the signal by C, expressed in primed coordinates. And as I requested,
> please specify whether you use the (x',t') or (t',x') convention, because your
> answers so far haven't made any sense either way.

I don't know what you're referring to. It's lost in past posts and I'm not going back to
look for it. In fact, YOU address my solution to Fig 4-4 before any further response
from me.

Just so YOU won't have to go back and look it up:
------------------------------

"We build a spacetime by taking instantaneous snapshots of space at successive
instants of time and stacking them up."

http://www.pitt.edu/~jdnorton/teaching/HPS_0410/chapters/spacetime/

This is EXACTLY what a laboratory scenario does, and it relegates "spacetime" to a
concept rather than a "fabric" that can be "ripped apart." In an instantaneous snapshot
of space, there is no future and no past. In Figure 4-4:

https://en.wikipedia.org/wiki/Special_relativity#Graphical_representation_of_the_Lorentz_transformation

the possibility of D at (L,vL/c²) sending tachyons to C at (0,0) is presumed, but the
Norton/lab instantaneous view would have C at (v²L/c², vL/c²) when B initiates the
message and passes it to D. But A is at (0,vL/c²) and C is not adjacent to A so no
"hand-off" is possible.

In order to have a hand-off, another moving observer, P, must be to the left of C which
is adjacent to A at t = vL/c² (0,vL/c²).

tP' = g(vL/c² - 0), so u' = 0 - gL)/(gvL/c² - 0) = -c²/v.

This event (0,vL/c²) occurs at the same place in both frames, [-v²L/c²,gvL/c²] in S', so
the fictitious spacetime isn't "ripped apart" even if it physically existed. And causality
is preserved, too. And the issue becomes consistent with the direct communication
scenario between moving observers.

-------------------------------------
A Minkowski diagram which depicts thiswas given way back in version 1 of my paper:

https://vixra.org/pdf/1908.0306v1.pdf

See Figure 4, which shows that in order to complete a hand-off, the tachyon signal
must go to Observer P, not C. And tP' = gvL/c². And tD' = 0. What is ∆t for a
particle moving from D to P?

[coea...@gmail.com]

On Monday, October 5, 2020 at 8:52:07 PM UTC-7, Gary Harnagel wrote:
> > The combination of the stipulated context and your single added claim
> > leads to closed causal loops (see above), which proves that your added
> > claim (superluminal signaling) is false.
>

> ...tachyons don't "create causal loops."

Again, any superluminal signaling ability in the context of special relativity would imply the ability to create causal loops as follows: A can transmit a message to B at speed (say) 10c in terms of their mutual rest frame, and B can immediately transmit the message to D at speed 1c as they cross paths (with mutual speed c/2), and D can immediately transmit the message to C at speed 10c in terms of their mutual rest frame, and C can immediately transmit the message to A at speed 1c as they cross paths. But this implies that the message is received by A from C prior to being transmitted by A, which entails a causal loop.

> I've presented irrefutable proof that tachyons don't create your
> so-called "causal loops."

Not true. The above reasoning (which of course goes back over a century) is iron-clad and irrefutable. Nothing you have said provides the slightest hint of a rational refutation of the above standard proof. In order to refute the proof, you would need to say which of the premises you deny, but you've already admitted you don't deny any of them, nor can you refute the logic that leads unavoidably to the conclusion that those premises imply the ability to create causal loops.

[Ross A. Finlayson]

Maybe the continuity of space-time is a bit more resilient and rip-stop
than you make it, and there is Fitzgerald after Lorentz for space-contraction
instead of length-contraction and time-dilation, making for a total field and
a unified or "single-world" field besides, that simply equips good old
Einstein's Theory of Relativity with what for the metric and being a gauge
theory, that it has one, and just one, that relativistic motion brings its
frame along, and the "conflict" is in your head on your paper, not violating
causality at all, because of course cause and effect.

This just as well explains the past experiments and future ones with
the tachyonic where light is always fleeting besides.

Of course, it so results than that physicists would have to learn potential
theory and stand up busts of Fritz London and arrive at quite a thorough
mathematical sophistication, and for a bit of change to the curriculum
besides, that GTR still holds up and in a Minkowski space-time, but
with time as a ray, that the rest of the 3+1 is just a space for projection,
and that space contraction occurs what keeps the geodesy current
(always, and everywhere).

[Prokaryotic Capase Homolog]

On Monday, October 5, 2020 at 11:24:19 PM UTC-5, Gary Harnagel wrote:
> On Monday, October 5, 2020 at 9:28:07 PM UTC-6, prokaryotic.c...@gmail.com wrote:

> > Re-read my question. I specifically referred to THIS IMAGE:
> > https://tinyurl.com/yy5tugup
>
> I don't care about that image.
>
> > > > And please specify whether you are using (x',t') or (t',x') convention. Since your
> > > > previous answer made NO SENSE either way, I found it impossible to plot.
> > > >
> > > > If "v" shows up anywhere in your answer, it means that you deny the principle of
> > > > relativity.
> > >
> > > So if L shows up anywhere, it means that denies PoR, too? Don't you even realize
> > > L is a parameter, too, just like v? You seem to have gone completely bonkers.
> > > You need to take some deep breaths and try to regather your wits about you.
> >
> > Don't be silly. L is the proper distance between C and D.
>
> OF COURSE IT IS.

If you are referring to Figure 4-4, you are wrong. In Figure 4-4, you have
consistently used L to refer to the proper distance between A and B,
not C and D. I myself never used the letter "L" in the Wikipedia article.
Although in figure https://tinyurl.com/yy5tugup, I happened to use several
of the same letters used in Figure 4-4, they are different diagrams.

> AND v IS THE RELATIVE VELOCITY IN A PARTICULAR EXPERIMENT.

Your use of L for Figure 4-4 is scaled by a factor of gamma from MY use of
the letter L for https://tinyurl.com/yy5tugup. In your calculations above, you
deal exclusively with lab frame coordinates. I had specifically asked for
PRIMED coordinates.

So I'll have to work out what you believe the primed coordinates to be for
myself based on your presentation above, as follows:

In Figure 4-4,
D at (x,t) = (L,vL/c²) transforms to (x',t') = (L/γ,0)
C at (x,t) = (v²L/c², vL/c²) transforms to (x',t') = (0,vL/(γc²))

After scaling the "L" in your calculations above by a factor of gamma, it is
apparent that in figure https://tinyurl.com/yy5tugup, you believe that a
superluminal signal emitted from object D at (x',t') = (L,0) crosses
horizontally to meet up with object C at point (x',t') = (0,vL/c²)

In https://tinyurl.com/yy5tugup, there are no hand-offs and no interactions
with the lab frame. Nevertheless, the letter "v" appears in the computation
for the primed coordinates of where the superluminal signal emitted from
object D meets up with object C.

*** The letter "v" has no business being in that computation. ***

Your fallacious "physics" is in total agreement with the fallacious "physics"
that I described in
https://drive.google.com/file/d/1mZJcqaV2KieXFNU5iWHCsVtDK21HOLWE/view?usp=sharing

In other words, the laws of your "physics" in the primed frame depend on the
speed of the primed frame relative to the lab frame, which is in total conflict
with the PoR.

Admit it, Gary. You are a crackpot.

[Maciej Wozniak]

On Tuesday, 6 October 2020 11:44:19 UTC+2, Prokaryotic Capase Homolog wrote:
> On Monday, October 5, 2020 at 11:24:19 PM UTC-5, Gary Harnagel wrote:
> > On Monday, October 5, 2020 at 9:28:07 PM UTC-6, prokaryotic.c...@gmail.com wrote:
>
> > > Re-read my question. I specifically referred to THIS IMAGE:
> > > https://tinyurl.com/yy5tugup
> >
> > I don't care about that image.
> >
> > > > > And please specify whether you are using (x',t') or (t',x') convention. Since your
> > > > > previous answer made NO SENSE either way, I found it impossible to plot.
> > > > >
> > > > > If "v" shows up anywhere in your answer, it means that you deny the principle of
> > > > > relativity.
> > > >
> > > > So if L shows up anywhere, it means that denies PoR, too? Don't you even realize
> > > > L is a parameter, too, just like v? You seem to have gone completely bonkers.
> > > > You need to take some deep breaths and try to regather your wits about you.
> > >
> > > Don't be silly. L is the proper distance between C and D.
> >
> > OF COURSE IT IS.
>
> If you are referring to Figure 4-4, you are wrong. In Figure 4-4, you have
> consistently used L to refer to the proper distance between A and B,
> not C and D. I myself never used the letter "L" in the Wikipedia article.
> Although in figure https://tinyurl.com/yy5tugup, I happened to use several
> of the same letters used in Figure 4-4, they are different diagrams.

You're wasting your time. He's a relativist, he is logic
immune.

[Prokaryotic Capase Homolog]

On Tuesday, October 6, 2020 at 5:13:12 AM UTC-5, Maciej Wozniak wrote:

> You're wasting your time. He's a relativist, he is logic
> immune.

No, Gary is NOT a relativist. He only THINKS that he is.

There is a big difference.

A few pseudo-relativists have managed to achieve a fair amount of
notoriety on these newsgroups. I imagine that some of us oldsters
remember "Uncle Al" with a certain degree of "fondness", if you want
to call it that. Although a good organic chemist, he was a total
bigot and crackpot who, unaware of his own crackpottery, was always
ready to skewer anti-relativists with delightfully inventive,
blasphemous, scatalogical insults. He still maintains a hate-filled
website http://www.mazepath.com/uncleal/

[Bob Ebbs]

Prokaryotic Capase Homolog wrote:

> On Tuesday, October 6, 2020 at 5:13:12 AM UTC-5, Maciej Wozniak wrote:
>
>> You're wasting your time. He's a relativist, he is logic immune.
>
> No, Gary is NOT a relativist. He only THINKS that he is.
> There is a big difference.

You indulge yourself. Dr. Gary knows more relativity than you ever did. A
bit of tensors, maybe, but at least he is honest. You however, have been
proved stupid in relativity many times.

> A few pseudo-relativists have managed to achieve a fair amount of
> notoriety on these newsgroups. I imagine that some of us oldsters
> remember "Uncle Al" with a certain degree of "fondness", if you want to
> call it that. Although a good organic chemist, he was a total bigot and
> crackpot who, unaware of his own crackpottery, was always ready to
> skewer anti-relativists with delightfully inventive, blasphemous,
> scatalogical insults. He still maintains a hate-filled website
> http://www.mazepath.com/uncleal/

How convenient, trashing a former poster in his absence. You disgusting
hypocrites should be banned from science forums, and from science
altogether.

[Maciej Wozniak]

On Tuesday, 6 October 2020 12:31:52 UTC+2, Prokaryotic Capase Homolog wrote:
> On Tuesday, October 6, 2020 at 5:13:12 AM UTC-5, Maciej Wozniak wrote:
>
> > You're wasting your time. He's a relativist, he is logic
> > immune.
>
> No, Gary is NOT a relativist. He only THINKS that he is.

:)
Were crusader knights not christians?

BTW, your guru has shown euclidean geometry can't be applied
when gravity is not insignificant; why do you ignore it?

[Gary Harnagel]

On Monday, October 5, 2020 at 11:00:09 PM UTC-6, coea...@gmail.com wrote:
>
> On Monday, October 5, 2020 at 8:52:07 PM UTC-7, Gary Harnagel wrote:
> >
> > > The combination of the stipulated context and your single added claim
> > > leads to closed causal loops (see above), which proves that your added
> > > claim (superluminal signaling) is false.
> >
> > ...tachyons don't "create causal loops."
>
> Again, any superluminal signaling ability in the context of special relativity would imply
> the ability to create causal loops as follows: A can transmit a message to B at speed
> (say) 10c in terms of their mutual rest frame, and B can immediately transmit the message
> to D at speed 1c as they cross paths (with mutual speed c/2),

Well, no. They are limited to "mutual speeds" of c²/v. This is what I've always claimed but
you continually misrepresent it.

> and D can immediately transmit the message to C at speed 10c in terms of their mutual
> rest frame, and C can immediately transmit the message to A at speed 1c as they cross
> paths. But this implies that the message is received by A from C prior to being transmitted
> by A, which entails a causal loop.

"By denying scientific principles, one may maintain any paradox." -- Galileo Galilei

> > I've presented irrefutable proof that tachyons don't create your
> > so-called "causal loops."
>
> Not true.

Yes, it IS true. The proof has been clearly laid out. Maybe you're not as intelligent as I
thought you were.

> The above reasoning (which of course goes back over a century) is iron-clad and
> irrefutable.

Iron rusts in less than a century. And tachyons weren't characterized relativistically
until 58 years ago. And you STILL deny those characteristics as well as the basis
behind the Minkowski diagram:

http://www.pitt.edu/~jdnorton/teaching/HPS_0410/chapters/spacetime/index.html

"We build a spacetime by taking instantaneous snapshots of space at successive
instants of time and stacking them up."

Which is exactly what the laboratory scenario is.

> Nothing you have said provides the slightest hint of a rational refutation of the above
> standard proof.

You haven't presented one iota of proof of your baseless assertion. What you believe
to be proof of your assertion is soundly refuted by tachyon properties and and Norton's
definition of spacetime.

> In order to refute the proof, you would need to say which of the premises you deny,

Clearly, you completely miss the point that speed of communication between moving
observers, whether direct or in the hand-off method is limited to c²/v.

> but you've already admitted you don't deny any of them,

I deny that when you cobble together tachyon speed of 10c with v = c/2, you make any
sense whatever.

> nor can you refute the logic that leads unavoidably to the conclusion that those premises
> imply the ability to create causal loops.

As I see it, a "causal loop" means a message is sent into the past, as you described above.
If speeds of communication are limited to c²/v, that can't happen. I've proven that such
speeds ARE limited to c²/v, Q,E.D.

[coea...@gmail.com]

On Tuesday, October 6, 2020 at 5:36:37 AM UTC-7, Gary Harnagel wrote:
> > Any superluminal signaling ability in the context of special relativity

> > would imply the ability to create causal loops as follows: A can
> > transmit a message to B at speed (say) 10c in terms of their mutual
> > rest frame, and B can immediately transmit the message to D at speed
> > 1c as they cross paths (with mutual speed c/2),
>
> Well, no. They are limited to "mutual speeds" of c²/v.

Objects B and D are ordinary material objects following timelike paths, and object D is moving at speed c/2 in terms of inertial coordinates in which B is at rest. Naturally B is moving with speed c/2 in terms of inertial coordinates in which D is at rest. Hence c/2 is their mutual speed. The signal sent from B to D as they cross paths has speed c in terms of each of those inertial coordinate systems. This is all part of the stipulated context of special relativity.

> > and [according to you] D can immediately transmit the message to C at

> > speed 10c in terms of their mutual rest frame, and C can immediately
> > transmit the message to A at speed 1c as they cross paths. But this
> > implies that the message is received by A from C prior to being
> > transmitted by A, which entails a causal loop.
> >

> > Nothing you have said provides the slightest hint of a rational
> > refutation of the above standard proof.
>

> I deny that when you cobble together tachyon speed of 10c with v = c/2,
> you make any sense whatever.

The speed c/2 is simply the speed of the objects C,D in terms of the inertial coordinates in which objects A,B are at rest, and vice versa. The quantity 10c is just an example of a putative superluminal speed at which you claim a signal can be sent and received between two mutually resting objects, such as from A to B, or from D to C. Which part of this don't you understand?

> If speeds of communication are limited to c²/v, that can't happen.

For the putative superluminal signal from A to B, the relative speed between A and B is zero. Likewise for the putative superluminal signal from D to C, the relative speed between D and C is zero. So, according to you, each of those transmissions can propagate at 10c in terms of the mutual rest frame of the transmitter and receiver. (In your terminology, v=0.)

The only other transmissions in the loop are ordinary light signals (speed=c) between ordinary objects passing each other at subluminal mutual speed, which is stipulated as part of the context of ordinary special relativity. But when combined with your putative superluminal signaling (above), the result is a causal loop. Hence your putative superluminal signaling is impossible in the context of special relativity.

This is hardly surprising, since every directed spacelike interval goes in the negative time direction of infinitely many inertial coordinate systems, and if signaling along such an interval was possible in terms of one such system it must, by the principle of relativity, be possible in terms of every other such system, and hence causal loops could trivially be constructed, as we've shown explicitly.

[Gary Harnagel]

On Tuesday, October 6, 2020 at 3:44:19 AM UTC-6, prokaryotic.c...@gmail.com wrote:
>
> On Monday, October 5, 2020 at 11:24:19 PM UTC-5, Gary Harnagel wrote:
> >
> > On Monday, October 5, 2020 at 9:28:07 PM UTC-6, prokaryotic.c...@gmail.com wrote:
> > >
> > > Re-read my question. I specifically referred to THIS IMAGE:
> > > https://tinyurl.com/yy5tugup
> >
> > I don't care about that image.
> >
> > > > > And please specify whether you are using (x',t') or (t',x') convention. Since your
> > > > > previous answer made NO SENSE either way, I found it impossible to plot.
> > > > >
> > > > > If "v" shows up anywhere in your answer, it means that you deny the principle of
> > > > > relativity.
> > > >
> > > > So if L shows up anywhere, it means that denies PoR, too? Don't you even realize
> > > > L is a parameter, too, just like v? You seem to have gone completely bonkers.
> > > > You need to take some deep breaths and try to regather your wits about you.
> > >
> > > Don't be silly. L is the proper distance between C and D.
> >
> > OF COURSE IT IS.
>
> If you are referring to Figure 4-4, you are wrong. In Figure 4-4, you have
> consistently used L to refer to the proper distance between A and B,
> not C and D.

Yes, L is the proper distance between A and B in Figure 4-4. Saying L is
the proper distance between C and D without reference to the figure you're
referring to and then claiming I'm wrong is ludicrous.

> I myself never used the letter "L" in the Wikipedia article.

So what? All that has done is given you license to mislead.
Are you saying since you didn't specify it, it doesn't exist. Are you asserting
that specifying an algebraic parameter to some distance is WRONG?

> Although in figure https://tinyurl.com/yy5tugup, I happened to use several
> of the same letters used in Figure 4-4, they are different diagrams.

Why go to the trouble of making different diagrams? You're just rearranging
the cookies and claiming that changes how many there are.

And I gave them to you. Do you have reading problems? Need glasses?

> So I'll have to work out what you believe the primed coordinates to be for
> myself based on your presentation above, as follows:

Is THAT such a hard thing for you?

> In Figure 4-4,
> D at (x,t) = (L,vL/c²) transforms to (x',t') = (L/γ,0)
> C at (x,t) = (v²L/c², vL/c²) transforms to (x',t') = (0,vL/(γc²))

Yep, that's what I got, too. See above.

> After scaling the "L" in your calculations above by a factor of gamma, it is
> apparent that in figure https://tinyurl.com/yy5tugup, you believe that a
> superluminal signal emitted from object D at (x',t') = (L,0) crosses
> horizontally to meet up with object C at point (x',t') = (0,vL/c²)

Yep, that's why C can't hand-off the message to A and why P is necessary.

> In https://tinyurl.com/yy5tugup, there are no hand-offs and no interactions
> with the lab frame.

Then no causality violation is possible. So what are you trying to say?

> Nevertheless, the letter "v" appears in the computation
> for the primed coordinates of where the superluminal signal emitted from
> object D meets up with object C.
>
> *** The letter "v" has no business being in that computation. ***
>
> Your fallacious "physics" is in total agreement with the fallacious "physics"
> that I described in
> https://drive.google.com/file/d/1mZJcqaV2KieXFNU5iWHCsVtDK21HOLWE/view?usp=sharing
>
> In other words, the laws of your "physics" in the primed frame depend on the
> speed of the primed frame relative to the lab frame, which is in total conflict
> with the PoR.
>
> Admit it, Gary. You are a crackpot.

Admit it, PCH, you're in denial of laboratory physics as well as of the definition of
spacetime:

"We build a spacetime by taking instantaneous snapshots of space at successive
instants of time and stacking them up."

I take an instantaneous snapshot of A, B, C and D at t = vL/c² and find that when
D is adjacent to B, C is NOT adjacent to A. YOU are in denial of this. And when we
introduce another moving observer, P, such that P IS adjacent to A at t = vL/c²,
tP' = gvL/c². So D MUST communicate with P at u' = -c²/v to effect the hand-off.

Curiously, this is infinitely fast in the lab frame:

u' = (u - v)/(1 - uv/c²) so u = (u' + v)/(1 + u'v/c²)

u = (-c²/v + v)/(1 - 1)

[Gary Harnagel]

On Tuesday, October 6, 2020 at 7:47:27 AM UTC-6, coea...@gmail.com wrote:
>
> On Tuesday, October 6, 2020 at 5:36:37 AM UTC-7, Gary Harnagel wrote:
> >
> > > Any superluminal signaling ability in the context of special relativity
> > > would imply the ability to create causal loops as follows: A can
> > > transmit a message to B at speed (say) 10c in terms of their mutual
> > > rest frame, and B can immediately transmit the message to D at speed
> > > 1c as they cross paths (with mutual speed c/2),
> >
> > Well, no. They are limited to "mutual speeds" of c²/v.
>
> Objects B and D are ordinary material objects following timelike paths, and object
> D is moving at speed c/2 in terms of inertial coordinates in which B is at rest.

? Naturally B is moving with speed c/2 in terms of inertial coordinates in which D

> is at rest. Hence c/2 is their mutual speed. The signal sent from B to D as they
> cross paths has speed c in terms of each of those inertial coordinate systems
>. This is all part of the stipulated context of special relativity.

And your point is? That's just ONE piece of the puzzle. You try to take a random
piece (like u' = -10c) that doesn't fit the first piece and try to cram them together.

> > > and [according to you] D can immediately transmit the message to C at
> > > speed 10c in terms of their mutual rest frame, and C can immediately
> > > transmit the message to A at speed 1c as they cross paths. But this
> > > implies that the message is received by A from C prior to being
> > > transmitted by A, which entails a causal loop.
> > >
> > > Nothing you have said provides the slightest hint of a rational
> > > refutation of the above standard proof.
> >
> > I deny that when you cobble together tachyon speed of 10c with v = c/2,
> > you make any sense whatever.

> The speed c/2 is simply the speed of the objects C,D in terms of the inertial
> coordinates in which objects A,B are at rest, and vice versa. The quantity 10c
> is just an example of a putative superluminal speed at which you claim a signal
> can be sent and received between two mutually resting objects, such as from
> A to B, or from D to C. Which part of this don't you understand?

Which part don't YOU understand about trying to cram two puzzle pieces together
that don't fit? The PROPER puzzle piece must fit u' = -c²/v. This means that if
you INSIST that u' = -10c, then v MUST equal 0.1c. Or if you INSIST that v = c/2,
then u' = 2c, not 10c, in order to complete the signal loop.

> > If speeds of communication are limited to c²/v, that can't happen.
>
> For the putative superluminal signal from A to B, the relative speed between A
> and B is zero. Likewise for the putative superluminal signal from D to C, the
> relative speed between D and C is zero. So, according to you, each of those
> transmissions can propagate at 10c in terms of the mutual rest frame of the
> transmitter and receiver. (In your terminology, v=0.)

BUT, they can't complete a signal loop unless the relative speed between frames
is 0,1c or less. You seem to be completely oblivious to your error.

> [Rest of nonsense deleted]

Neither you nor PCH has addressed the fact that direct tachyon communication
between moving observers does NOT violate causality, does NOT create a "causal
loop." Furthermore, my introduction of moving observer P prevents causal loops
in the hand-off method, making the hand-off method consistent with direct
communication. Why IS that? Is it because you realize that it would destroy
your assertions? Chicken?

[Bob Ebbs]

Gary Harnagel wrote:

>> I myself never used the letter "L" in the Wikipedia article.
>
> So what? All that has done is given you license to mislead.
> Are you saying since you didn't specify it, it doesn't exist. Are you
> asserting that specifying an algebraic parameter to some distance is
> WRONG?

Absolutely. These guys know less than we do in physics, but will not stop
them from saying we are wrong. Keep it up with the good work, Dr. Gary.
If I can help with arduino etc, just leave a message.

[Dono.]

On Tuesday, October 6, 2020 at 7:27:28 AM UTC-7, hit...@yahoo.com wrote:

> Neither you nor PCH has addressed the fact that direct tachyon communication
> between moving observers does NOT violate causality, does NOT create a "causal
> loop."

Repeating the same idiotic lie doesn't make it true.

[coea...@gmail.com]

On Tuesday, October 6, 2020 at 7:27:28 AM UTC-7, Gary Harnagel wrote:
> > According to you, A can transmit a message to B at speed (say) 10c

> > in terms of their mutual rest frame, and B can immediately transmit
> > the message to D at speed 1c as they cross paths (with mutual speed

> > c/2), and [according to you] D can immediately transmit the message

> > to C at speed 10c in terms of their mutual rest frame, and C can
> > immediately transmit the message to A at speed 1c as they cross paths.
> > But this implies that the message is received by A from C prior to
> > being transmitted by A, which entails a causal loop.
>

> If you INSIST that u' = -10c, then v MUST equal 0.1c.

The quantity 10c refers to the speed of the putative superluminal signal from A to B, which are mutually stationary objects, and from D to C, which are also mutually stationary objects. If you define the symbol "v" as representing the speed between transmitter and receiver, then v=0 in both cases.

> Or if you INSIST that v = c/2...

I do not. Again, the speed between transmitter and receiver for these putative superluminal signals is zero in both cases. The speed c/2 is the mutual speed between the pairs of ordinary objects A,B and C,D.

> > For the putative superluminal signal from A to B, the relative speed
> > between A and B is zero. Likewise for the putative superluminal signal
> > from D to C, the relative speed between D and C is zero. So, according
> > to you, each of those transmissions can propagate at 10c in terms of
> > the mutual rest frame of the transmitter and receiver. (In your
> > terminology, v=0.)
>
> BUT, they can't complete a signal loop unless the relative speed between

> frames is 0.1c or less.

Again, the putative superluminal signal from A to B is between mutually resting objects, as is the putative superluminal signal from D to C. Both of these signals satisfy your requirements (because v=0). The only other signals in the loop are between ordinary subluminal objects with ordinary light signals as they pass each other. Those are stipulated in the context of special relativity, but together with your putative superluminal signaling capability they would comprise a closed causal loop, which proves that your putative superluminal signaling is impossible in the context of special relativity.

[Prokaryotic Capase Homolog]

On Tuesday, October 6, 2020 at 9:27:28 AM UTC-5, Gary Harnagel wrote:

> Neither you nor PCH has addressed the fact that direct tachyon communication
> between moving observers does NOT violate causality, does NOT create a "causal
> loop." Furthermore, my introduction of moving observer P prevents causal loops
> in the hand-off method, making the hand-off method consistent with direct
> communication. Why IS that? Is it because you realize that it would destroy
> your assertions? Chicken?

However, your proposed means of preventing the transmission of tachyonic signals
back in time thoroughly trashes the Principle of Relativity.

By way of analogy, the speed of light that one measures does not show diurnal
30 km/s variation due to Earth's passage through the aether. The presence of "v"
in the expression for where the tachyonic signal from D intersects C's world line
should surely be a warning sign to you that something is VERY WRONG with your
theory.

[Ross A. Finlayson]

A conciliatory explanation has it actually contracts the space,
and with a fluid model what that space-time (or rather, the space)
is continuous and a manifold, what its changes in content only
result in distortions ("torsion" usually eg using Rindler's) not de-fabrications.

[Gary Harnagel]

On Tuesday, October 6, 2020 at 9:20:20 AM UTC-6, coea...@gmail.com wrote:
>
> On Tuesday, October 6, 2020 at 7:27:28 AM UTC-7, Gary Harnagel wrote:
> >
> > > According to you, A can transmit a message to B at speed (say) 10c
> > > in terms of their mutual rest frame, and B can immediately transmit
> > > the message to D at speed 1c as they cross paths (with mutual speed
> > > c/2), and [according to you] D can immediately transmit the message
> > > to C at speed 10c in terms of their mutual rest frame, and C can
> > > immediately transmit the message to A at speed 1c as they cross paths.
> > > But this implies that the message is received by A from C prior to
> > > being transmitted by A, which entails a causal loop.
> >
> > If you INSIST that u' = -10c, then v MUST equal 0.1c.
>
> The quantity 10c refers to the speed of the putative superluminal signal
> from A to B, which are mutually stationary objects, and from D to C, which
> are also mutually stationary objects. If you define the symbol "v" as
> representing the speed between transmitter and receiver, then v=0 in both cases.

No! v is the velocity between A and C (or B and D). Or between S' and S. It's
ALWAYS been that, so where did your stupid nonsense originate?

> > Or if you INSIST that v = c/2...
>
> I do not.

But you DO! I didn't come up with that c/s, YOU did.

>Again, the speed between transmitter and receiver for these putative superluminal signals is zero in both cases. The speed c/2 is the mutual speed between the pairs of ordinary objects A,B and C,D.
> > > For the putative superluminal signal from A to B, the relative speed
> > > between A and B is zero. Likewise for the putative superluminal signal
> > > from D to C, the relative speed between D and C is zero. So, according
> > > to you, each of those transmissions can propagate at 10c in terms of
> > > the mutual rest frame of the transmitter and receiver. (In your
> > > terminology, v=0.)
> >
> > BUT, they can't complete a signal loop unless the relative speed between
> > frames is 0.1c or less.
>
> Again, the putative superluminal signal from A to B is between mutually resting
> objects, as is the putative superluminal signal from D to C. Both of these signals
> satisfy your requirements (because v=0). The only other signals in the loop are
> between ordinary subluminal objects with ordinary light signals as they pass each
> other.

At v = c/2, dissembler. The speed BETWEEN S and S' determines the limit at which
a hand-off can be successfully effected.

> Those are stipulated in the context of special relativity, but together with your
> putative superluminal signaling capability they would comprise a closed
> causal loop, which proves that your putative superluminal signaling is
> impossible in the context of special relativity.

You try to produce a paradox by impossible means. Your argument is
simplistic, at best.

"By denying scientific principles, one may maintain any paradox."
-- Galileo Galilei

You've either not read or not understood what I'm proposing.

And you continue to refuse to address direct tachyon communication.

[Gary Harnagel]

On Tuesday, October 6, 2020 at 10:14:25 AM UTC-6, prokaryotic.c...@gmail.com wrote:
>
> On Tuesday, October 6, 2020 at 9:27:28 AM UTC-5, Gary Harnagel wrote:
> >
> > Neither you nor PCH has addressed the fact that direct tachyon communication
> > between moving observers does NOT violate causality, does NOT create a "causal
> > loop." Furthermore, my introduction of moving observer P prevents causal loops
> > in the hand-off method, making the hand-off method consistent with direct
> > communication. Why IS that? Is it because you realize that it would destroy
> > your assertions? Chicken?
>
> However, your proposed means of preventing the transmission of tachyonic signals
> back in time thoroughly trashes the Principle of Relativity.

Impossible.

> By way of analogy, the speed of light that one measures does not show diurnal
> 30 km/s variation due to Earth's passage through the aether.

Why is that an "analogy"? It's nonsense.

> The presence of "v" in the expression for where the tachyonic signal from D
> intersects C's world line should surely be a warning sign to you that something is
> VERY WRONG with your theory.

The "v" you so rage about is from t' = γ(t - vx/c²). Or for a particular value of x, L:
t' = γ(t - vL/c²). So you're saying "v" in that equation is a "warning sign" that
something is VERY WRONG with the Lorentx transform? Have you gone completely
NUTS?! Don't you realize that vL/c² is a TIME? That it's the first-order factor in RoS?

So you're saying that in a given problem with given values for v and L, you won't
accept that vL/c² represents a certain time? Are you totally bonkers?!

You and coeal better start LEARNING something instead of posting inanities and
misconceptions.

[Prokaryotic Capase Homolog]

You don't even understand the problem. INCREDIBLE ignorance on your part.

[coea...@gmail.com]

On Tuesday, October 6, 2020 at 3:11:20 PM UTC-7, Gary Harnagel wrote:
>>>> According to you, A can transmit a message to B at speed (say) 10c
>>>> in terms of their mutual rest frame, and B can immediately transmit
>>>> the message to D at speed 1c as they cross paths (with mutual speed
>>>> c/2), and [according to you] D can immediately transmit the message
>>>> to C at speed 10c in terms of their mutual rest frame, and C can
>>>> immediately transmit the message to A at speed 1c as they cross paths.
>>>> But this implies that the message is received by A from C prior to
>>>> being transmitted by A, which entails a causal loop.
>>>
>>> If you INSIST that u' = -10c, then v MUST equal 0.1c.
>>
>> The quantity 10c refers to the speed of the putative superluminal signal
>> from A to B, which are mutually stationary objects, and from D to C,
>> which are also mutually stationary objects. If you define the symbol "v"
>> as representing the speed between transmitter and receiver, then v=0 in
>> both cases.
>

> [I define] v as the velocity between A and C (or B and D).

In that case it's irrelevant. The objects A and B are both at rest in a given system of inertial coordinates, and according to you A can send a signal to B at speed 10c in terms of these coordinates. Likewise the objects C and D are both at rest in a given system of inertial coordinates, and according to you D can send a signal to C at speed 10c in terms of these coordinates.

> > > Or if you INSIST that v = c/2...
> >
> > I do not.
>
> But you DO!

I'm referring to the speed between the transmitter and receiver of a putative superluminal signal, noting that those speeds are zero for both of the putative superluminal signals. It goes without saying that the infinitely many speeds of those two objects relative to infinitely many completely uninvolved objects cannot be relevant.

>> Again, the speed between transmitter and receiver for these putative
>> superluminal signals is zero in both cases. The speed c/2 is the mutual
>> speed between the pairs of ordinary objects A,B and C,D.

>> Again, the putative superluminal signal from A to B is between mutually
>> resting objects, as is the putative superluminal signal from D to C. Both
>> of these signals satisfy your requirements (because v=0). The only other
>> signals in the loop are between ordinary subluminal objects with ordinary
>> light signals as they pass each other.
>

> At v = c/2...

Right, and it is stipulated that ordinary material objects moving at any subluminal speed relative to each other can send light signals over the arbitrarily short distance between them as they pass. The ability to send luminal signals between ordinary subluminal objects is not in question.

> The speed BETWEEN S and S' determines the limit at which a hand-off
> can be successfully effected.

In the context of special relativity, any two subluminal objects can send a luminal signal from one to the other. The light signal has speed c in terms of each of the inertial coordinates in which each object is at rest. The only limitation on the relative speed between the material objects is that it be less than c. This is part of the stipulations entailed by special relativity.

>> Those are stipulated in the context of special relativity, but together
>> with your putative superluminal signaling capability they would comprise
>> a closed causal loop, which proves that your putative superluminal
>> signaling is impossible in the context of special relativity.
>
> You try to produce a paradox by impossible means. Your argument is
> simplistic, at best.

It is very simple, but it is not simplistic. This is the standard text-book proof that, in the context of special relativity, the ability to send superluminal signals would imply the ability to create closed causal loops. As you can see, it is iron-clad and irrefutable.

[Gary Harnagel]

On Tuesday, October 6, 2020 at 4:55:46 PM UTC-6, coea...@gmail.com wrote:
>
> On Tuesday, October 6, 2020 at 3:11:20 PM UTC-7, Gary Harnagel wrote:
> >
> > > The quantity 10c refers to the speed of the putative superluminal signal
> >> from A to B, which are mutually stationary objects, and from D to C,
> >> which are also mutually stationary objects. If you define the symbol "v"
> >> as representing the speed between transmitter and receiver, then v=0 in
> >> both cases.
> >
> > [I define] v as the velocity between A and C (or B and D).
>
> In that case it's irrelevant. The objects A and B are both at rest in a given system
> of inertial coordinates, and according to you A can send a signal to B at speed
> 10c in terms of these coordinates. Likewise the objects C and D are both at rest
> in a given system of inertial coordinates, and according to you D can send a
> signal to C at speed 10c in terms of these coordinates.

Since you completely misunderstand and misrepresent the hand-off method, even
after having it explained to you several times, there's no point in continuing this
charade with you.

> > > > Or if you INSIST that v = c/2...
> > >
> > > I do not.
> >
> > But you DO!
>
> I'm referring to the speed between the transmitter and receiver of a putative
> superluminal signal, noting that those speeds are zero for both of the putative
> superluminal signals.

Which is completely nonsisical. EVERYONE knows what the "v" means in the LT.
Except YOU, apparently. And you apparently don't understand that "v" is in the
LT where it is part of a TIME representation, a major part of RoS between frames.

> It goes without saying that the infinitely many speeds of those two objects
> relative to infinitely many completely uninvolved objects cannot be relevant.

Assertion with malice aforethought. Or is it just stupidity? Either is very bad
form. The least amount of thought would reveal that v is indeed involved. Even
YOU specify v = c/2 when setting up a problem, so your asinine claim that v isn't
involved is dishonesty or stupidity,

> >> Again, the speed between transmitter and receiver for these putative
> >> superluminal signals is zero in both cases. The speed c/2 is the mutual
> >> speed between the pairs of ordinary objects A,B and C,D.
> >> Again, the putative superluminal signal from A to B is between mutually
> >> resting objects, as is the putative superluminal signal from D to C. Both
> >> of these signals satisfy your requirements (because v=0). The only other
> >> signals in the loop are between ordinary subluminal objects with ordinary
> >> light signals as they pass each other.
> >
> > At v = c/2...
>
> Right, and it is stipulated that ordinary material objects moving at any subluminal
> speed relative to each other can send light signals over the arbitrarily short distance
> between them as they pass. The ability to send luminal signals between ordinary

> subluminal objects is not in question. The only limitation on the relative speed

> between the material objects is that it be less than c. This is part of the stipulations
> entailed by special relativity.

Which is only PART of the problem, as you well know. The other part is setting up
observers, moving and stationary, so they can do an effective hand-off. This requires
specifying v, L and initial positions.

> > The speed BETWEEN S and S' determines the limit at which a hand-off
> > can be successfully effected.
>
> In the context of special relativity, any two subluminal objects can send a luminal signal
> from one to the other. The light signal has speed c in terms of each of the inertial
> coordinates in which each object is at rest.

No one is contesting that, so why do you keep regurgitating it?

> > > Those are stipulated in the context of special relativity, but together
> > > with your putative superluminal signaling capability they would comprise
> > > a closed causal loop, which proves that your putative superluminal
> > > signaling is impossible in the context of special relativity.
> >
> > You try to produce a paradox by impossible means. Your argument is
> > simplistic, at best.
>
> It is very simple, but it is not simplistic.

Yes, it IS simplistic, which means WRONG. And you don't even realize it. Very sad.

> This is the standard text-book proof that, in the context of special relativity, the
> ability to send superluminal signals would imply the ability to create closed
> causal loops. As you can see, it is iron-clad and irrefutable.

Hahahahaha! Repeating a lie doesn't make it true. The lie you keep telling yourself
is that v doesn't matter. In that you are DEAD wrong. You look at Figure 4-4 and
say, "Oh, there's nothing wrong with that" when the time at A is tA = 0 and the time at
B is tB = vL/c². Fool! The perspective is from the frame in which A and B are
stationary, which means that tA = tB. Furthermore, tC and tD (times in the stationary
frame) are also related. All observers at a particular time in the stationary frame
lie on a horizontal line. This is what a physicist in a lab will see and is consistent
with the definition of a Minkowski diagram:

"We build a spacetime by taking instantaneous snapshots of space at successive
instants of time and stacking them up."

http://www.pitt.edu/~jdnorton/teaching/HPS_0410/chapters/spacetime/index.html#Building

This also demonstrates that when tB = vL/c², tA MUST equal vL/c² also. It also means
that tC and tC' are no longer zero, which means that C can't hand off the message to A.
So Figure 4-4 is dead wrong. It presumes connections which are impossible.

But you are blind to all of this. And I thought you were smarter than Dumbo Dono.

[Dono.]

On Tuesday, October 6, 2020 at 7:07:07 PM UTC-7, hit...@yahoo.com wrote:
> This is what a physicist in a lab will see and is consistent
> with the definition of a Minkowski diagram:

But you have no clue what a Minkowski diagram is. I proved that hundreds of posts ago.

[coea...@gmail.com]

On Tuesday, October 6, 2020 at 7:07:07 PM UTC-7, Gary Harnagel wrote:
> Even YOU specify v = c/2 when setting up a problem...

The speed c/2 was specified as the relative speed between A and C, but that is irrelevant to the fact that A and B are mutually stationary in an inertial coordinate system, and hence according to you A can send a message at speed 10c to B in terms of that system, and B can receive it. Likewise since C and D are mutually at rest, D can (according to you) send a message at speed 10c to C in terms of that system, and C can receive it. The relative speed between A and C does not affect the conditions for these two putative superluminal signals.

> > It is stipulated that ordinary material objects moving at

> > any subluminal speed relative to each other can send light signals over
> > the arbitrarily short distance between them as they pass. The ability
> > to send luminal signals between ordinary subluminal objects is not in
> > question. The only limitation on the relative speed between the
> > material objects is that it be less than c. This is part of the
> > stipulations entailed by special relativity.
>

> Which is only PART of the problem...

That's the part consisting of the luminal signals, which are not in question, and the other part (explained above) is your claimed superluminal signals, which lead to the causal loop, and hence are impossible. That's how the reductio ad absurdum proof works.

You've been misled by Norton's web page, where he omits any mention of the different foliations of spacetime due to the relativity of simultaneity. He depicts just a single foliation. I urge you to actually read a book on special relativity to learn about it. The relativity of simultaneity is perfectly explicit in the Lorentz transformation. Two events that are simultaneous in terms of one system of inertial coordinates are not in terms of another.

[Prokaryotic Capase Homolog]

Gary, take a look at these two Minkowski diagrams.
https://drive.google.com/file/d/1YaIG29kRVKjZWobqXc27aZfMTHRKRgrp/view?usp=sharing

Except for minor quibbles from the fact that I drew them freehand (and so my lengths
are not accurate), is there anything wrong with how I have drawn them? Please specify
what is wrong, and explain why.

[Maciej Wozniak]

He is a relativist. What do you expect?

[Prokaryotic Capase Homolog]

On Tuesday, October 6, 2020 at 10:01:54 PM UTC-5, coea...@gmail.com wrote:

> That's the part consisting of the luminal signals, which are not in question, and the other part (explained above) is your claimed superluminal signals, which lead to the causal loop, and hence are impossible. That's how the reductio ad absurdum proof works.
>
> You've been misled by Norton's web page, where he omits any mention of the different foliations of spacetime due to the relativity of simultaneity. He depicts just a single foliation. I urge you to actually read a book on special relativity to learn about it. The relativity of simultaneity is perfectly explicit in the Lorentz transformation. Two events that are simultaneous in terms of one system of inertial coordinates are not in terms of another.

I'm thinking of replacing the existing Fig. 4-4 in Wikipedia with a pair of figures
based on
https://drive.google.com/file/d/1YaIG29kRVKjZWobqXc27aZfMTHRKRgrp/view?usp=sharing
except that I would adjust the proper lengths of the arrows to accurately represent
the Lorentz factor.

However, as I've explained to you before, as a diligent Wikipedia editor, I need
to respect the "No original research" policy. The original pair of figures can
be solidly traced to a figure in Morin, the main difference being that I've broken
out his single original B&W figure into two figures and added color.

In a paragraph on "Routine calculations", it is stated, "Routine calculations do not
count as original research, provided there is consensus among editors that the result
of the calculation is obvious, correct, and a meaningful reflection of the sources.
Basic arithmetic, such as adding numbers, converting units, or calculating a person's
age are some examples of routine calculations."
https://en.wikipedia.org/wiki/Wikipedia:No_original_research#Routine_calculations

To me, the transformation between frames would count as a "routine calculation".
Do you think that I'd be stretching the rule here?

[Gary Harnagel]

On Tuesday, October 6, 2020 at 9:01:54 PM UTC-6, coea...@gmail.com wrote:
>
> On Tuesday, October 6, 2020 at 7:07:07 PM UTC-7, Gary Harnagel wrote:
> >
> > Even YOU specify v = c/2 when setting up a problem...
>
> The speed c/2 was specified as the relative speed between A and C, but that is
> irrelevant to the fact that A and B are mutually stationary in an inertial coordinate
> system, and hence according to you A can send a message at speed 10c to B in
> terms of that system, and B can receive it. Likewise since C and D are mutually
> at rest, D can (according to you) send a message at speed 10c to C in terms of
> that system, and C can receive it. The relative speed between A and C does not
> affect the conditions for these two putative superluminal signals.

Obviously, but you're in the business of telling half-truths. The speed between frames
IS relevant to whether or not a hand-off can be effected. L, v and positions of the
participants are all parameters that make or break the ability to create a message loop.

> > > It is stipulated that ordinary material objects moving at
> > > any subluminal speed relative to each other can send light signals over
> > > the arbitrarily short distance between them as they pass. The ability
> > > to send luminal signals between ordinary subluminal objects is not in
> > > question. The only limitation on the relative speed between the
> > > material objects is that it be less than c. This is part of the
> > > stipulations entailed by special relativity.
> >
> > Which is only PART of the problem...
>
> That's the part consisting of the luminal signals, which are not in question, and
> the other part (explained above) is your claimed superluminal signals, which
> lead to the causal loop, and hence are impossible. That's how the reductio ad
> absurdum proof works.

YOU certainly have been reduced to the absurd by your distortions.

> You've been misled by Norton's web page, where he omits any mention of the
> different foliations of spacetime due to the relativity of simultaneity. He depicts
> just a single foliation. I urge you to actually read a book on special relativity to
> learn about it.

This looks like another of your attempts to befuddle simple issues. It's OBVIOUS
that a MD includes RoS and it's OBVIOUS that a MD can be built from instantaneous
snap shots of the positions of the constituents, and that one can stack the snapshots
together and, voila, a MD emerges. All that's needed is to apply the LT to the
evolution on snapshot to the next.

>The relativity of simultaneity is perfectly explicit in the Lorentz transformation.

Exactly.

> Two events that are simultaneous in terms of one system of inertial coordinates
> are not in terms of another.

Which is demonstrated in a proper MD: one in which observers at rest all have
synchronized clocks, unlike Figure 4-4 which violates that principle.

[Gary Harnagel]

On Wednesday, October 7, 2020 at 3:06:11 AM UTC-6, prokaryotic.c...@gmail.com wrote:
>
> I'm thinking of replacing the existing Fig. 4-4 in Wikipedia with a pair of figures
> based on
> https://drive.google.com/file/d/1YaIG29kRVKjZWobqXc27aZfMTHRKRgrp/view?usp=sharing
> except that I would adjust the proper lengths of the arrows to accurately represent
> the Lorentz factor.

Yes, indeed, a good first step. But it doesn't cover what the spaceship observer cocludes
from his perspective. So B at t = vL/c² (I'm including parameters for v and L, positions are
already specified) passes a signal to D at tD' = 0, who transmits it to C at u' = -∞, who
receives it at tC' = 0 and passes it to A at t = 0. From the spaceship observer's perspective,
A transmits to B at u' = ∞, so it arrives at B whose clock reads tB = vL/c².

So the signal makes the loop in zero time (ideally), and causality is NOT violated.

Your lab frame is inconsistent with the spaceship frame because the arrival time at B has
already been determined by the spaceship observer: it arrives at tB = vL/c² (tB' = 0), so the
blue arrow MUST be slanted upward (along the x' axis so u' = ∞). Thus it agrees with the
view from the spaceship.

Of course, when u' = ∞, u = (u' + v)/(1 + u'v/c²) = c²/v.

> However, as I've explained to you before, as a diligent Wikipedia editor, I need
> to respect the "No original research" policy. The original pair of figures can
> be solidly traced to a figure in Morin, the main difference being that I've broken
> out his single original B&W figure into two figures and added color.
>
> In a paragraph on "Routine calculations", it is stated, "Routine calculations do not
> count as original research, provided there is consensus among editors that the result
> of the calculation is obvious, correct, and a meaningful reflection of the sources.
> Basic arithmetic, such as adding numbers, converting units, or calculating a person's
> age are some examples of routine calculations."
> https://en.wikipedia.org/wiki/Wikipedia:No_original_research#Routine_calculations
>
> To me, the transformation between frames would count as a "routine calculation".
> Do you think that I'd be stretching the rule here?

Not if you did them correctly :-)

By drawing the blue arrow horizontally you've introduced inconsistency in the two
views. This is what happens when you frame jump in the middle of an analysis.
The COMPLETE analysis must be done in each frame to ensure consistency.

By looking at both frames, you've inadvertently exposed the inconsistency prevalent
in all presentations of causality "violations." Even the direct communication
renditions in physics textbooks ignore the physics of tachyons and presume that
signalling speed can exceed the c²/v limit, which I've exposed in my paper:

https://vixra.org/pdf/1908.0306v3.pdf

Of course, I would still have a problem with your graphs even with the modified lab
frame (modified to be consistent with the spaceship frame). From the perspective
of the lab frame, the red arrow would appear to go backward in time, which means
it starts at tD = vL/c² (i.e., tD' = 0) and arrives at tC = tC' = 0.

There IS a spaceship observer's position that precludes this and still remains
consistent in both frames. I've discussed this position before and it has the satisfying
outcome that the roundtrip time is vL/c², not zero, making it consistent with direct
tachyon communication.

I'm afraid, however, that would entail original research to wikipedia :-|

They might even think correcting Figure 4-4 would be "stretching things." It's obvious
how ingrained the status quo is.

I'm working on a new paper where I have considered the view from S' and it's inconsistency
with the view from S. That's why I applauded your new approach.

[Prokaryotic Capase Homolog]

Amazing. Even when confronted with graphs explicitly showing the relationship
between the spaceship and lab views, you continue to misunderstand.

As Darth Vader might say, "I see that you are creating a new version of your
vixra paper. Your crackpottery is complete. Indeed, you are as misguided as
the Emperor has forseen."

[Gary Harnagel]

Amazing! Even when confronted by conclusive evidence that your two frames are
inconsistent, you still obstinately refuse to understand. It's a CHOICE you're making
to be wrong.

> As Darth Vader might say, "I see that you are creating a new version of your
> vixra paper. Your crackpottery is complete. Indeed, you are as misguided as
> the Emperor has forseen."

No, it's not a new "version." You DO jump often to incorrect conclusions. So go ahead
with your revised Figure 4-4. It will be held up as another obstinate example of
misconceptions about tachyon communication.

So you really truly believe that it's okay for S' to predict that tachyon speed in S will
be u = c²/v and then go ahead and pretend that you can make u = ∞. A crackpot
is someone who believes something that's inconsistent. That would be YOU.

So, PCH: Pot, kettle, black.

[coea...@gmail.com]

On Wednesday, October 7, 2020 at 4:02:16 AM UTC-7, Gary Harnagel wrote:
> > A and B are mutually stationary in an inertial coordinate system,
> > and hence according to you A can send a message at speed 10c to B in
> > terms of that system, and B can receive it. Likewise since C and D
> > are mutually at rest, D can (according to you) send a message at
> > speed 10c to C in terms of that system, and C can receive it. The
> > relative speed between A and C does not affect the conditions for
> > these two putative superluminal signals.
>

> The speed between frames IS relevant to whether or not a hand-off
> can be effected.

The ability to send luminal signals between ordinary subluminal objects is not in question. It is stipulated as part of special relativity that ordinary material objects moving at any subluminal speed relative to each other can send light signals to each other, including over the arbitrarily short distance between them as they pass. The only limitation on the relative speed between the material objects is that it be less than c. This is part of the stipulations entailed by special relativity. The specified speed c/2 complies with the requirement for the two objects (e.g., B and D) to be moving subluminally relative to each other.

> > That's the part consisting of the luminal signals, which are not in
> > question, and the other part (explained above) is your claimed
> > superluminal signals, which lead to the causal loop, and hence are
> > impossible. That's how the reductio ad absurdum proof works.
> >

> > You've been misled by Norton's web page, where he omits any mention of
> > the different foliations of spacetime due to the relativity of
> > simultaneity. He depicts just a single foliation. I urge you to

> > actually read a book on special relativity to learn about the skew
> > between the temporal foliations of relatively moving systems of
> > inertial coordinates. The relativity of simultaneity is perfectly
> > explicit in the Lorentz transformation. Two events that are

> > simultaneous in terms of one system of inertial coordinates
> > are not in terms of another.
>

> Observers at rest all have synchronized clocks...

We can synchronize clocks in infinitely many ways, but there is a unique temporal foliation associated with each system of inertial coordinates, and those foliations of simultaneity are skewed in the way described by the Lorentz transformation. As a consequence, every putative superluminal signal goes in the negative time direction of infinitely many systems of inertial coordinates, so if you believe (sensibly) that it is not possible to send signals in the negative time direction of an inertial coordinate system, you rule out the possibility of superluminal signaling.

> unlike Figure 4-4 which violates that principle.

Figure 4-4 depicts two putative superluminal signals, each of which goes in the negative time direction of some system of inertial coordinates, which does indeed violate the principles of physics... that's the point of the figure, to illustrate why superluminal signaling violates the principles of physics. You seem to agree that signals can't go in the negative time direction of an inertial coordinate system, but you fail to grasp that *every* putative superluminal signal goes in the negative time direction of some system of inertial coordinates, and hence we can rule out, not just some, but *all* superluminal signaling.

[Prokaryotic Capase Homolog]

A major difference between you and me is that all of my major writings are subject
to peer-review by dozens of eyes in Wikipedia, where I have contributed not only
under my current nym, but under a previous one which I no longer use. (There
are strict rules in Wikipedia against sock-puppetry, so once I decided to switch
nyms, I have STAYED switched.) Once and only once have I made a serious error of
fact in the article on special relativity, and when I did so, J. R. Spriggs quickly
caught me, and I just as quickly acknowledged my error.

There is no pot/kettle/black here.

[Gary Harnagel]

On Wednesday, October 7, 2020 at 7:49:59 AM UTC-6, coea...@gmail.com wrote:
>
> [Regurgitations deleted]

>
> Figure 4-4 depicts two putative superluminal signals, each of which goes in the negative
> time direction of some system of inertial coordinates, which does indeed violate the
> principles of physics...

Well, THAT'S the real question that's giving your gizzard indigestion, isn't it? That some
looky loo hypothetical "observer" uninvolved in creating the loop will be offended by
seeing a "result" occurring before its cause.

> that's the point of the figure, to illustrate why superluminal signaling violates the
> principles of physics.

But Figure 4-4 violates the principles of physics without regard to tachyons, pretending
that (1) two observers at rest with each other needed have their clocks synchronized
and (2) insisting that the past actually, physically exists and is accessible from the
present.

> You seem to agree that signals can't go in the negative time direction of an inertial
> coordinate system,

Irrelevant. Don't you believe that A and B can collude to have an event E1 happen after
an event E2 where it seems that E1 causes E2?

> but you fail to grasp that *every* putative superluminal signal goes in the negative
> time direction of some system of inertial coordinates,

You're dead wrong again. I DO realize that. You can look in the previous
thread and see where I addressed it. Simply this: A true causality violation occurs
when a message is sent back into the past and is returned to the sender before he
sent it, and that can only be done in the two frames directly involved with making
that (purportedly) happen. All these other busybody observers have no effect
whatever. Pretending that they're involved is an overreach in defining causality.

> and hence we can rule out, not just some, but *all* superluminal signaling.

By SOME people's "definition" of causality violation. Where do you think that
"definition" will go when tachyons are confirmed by experiment?

Right down the toilet where it belongs.

“When a distinguished but elderly scientist states that something is possible,
he is almost certainly right. When he states that something is impossible, he
is very probably wrong.” -- Arthur C. Clarke

YOU are very probably wrong. And you're not even a scientist. I am.

[Dono.]

On Wednesday, October 7, 2020 at 7:34:18 AM UTC-7, hit...@yahoo.com wrote:
> . And you're not even a scientist. I am.

Delusional imbecile

[Dono.]

On Wednesday, October 7, 2020 at 7:34:18 AM UTC-7, hit...@yahoo.com wrote:
>

> All these other busybody observers have no effect
> whatever. Pretending that they're involved is an overreach in defining causality.
> > and hence we can rule out, not just some, but *all* superluminal signaling.

Dumbestfuck,

PoR requires ALL observers to agree.

[Gary Harnagel]

So no one is making you correct your delusion, apparently because the mainstream
physics community is also deluded. It is totally absurd to believe that it's okay for
the spaceship observer to calculate that u = c²/v for the tachyon speed in S, but
for S to proclaim it can close the loop by sending tachyons faster.

“The fact that an opinion has been widely held is no evidence whatever
that it is not utterly absurd.” -- Bertrand Russell

And the widely-held opinion that tachyons violate causality is indeed totally absurd.
Your new version of 4-4 proves it, but you're too blind to see it.

BTW, my major writings have been published in peer-reviewed letters and journals.
In fact, I have reviewed papers for publishing. Not surprising since when an author
references a paper, the authors referenced are in danger of becoming peer reviewers.

This subject's not ready for prime time, but it's getting closer. For peer review it
must be very cogent and logically sound because the inertia resisting the concept
will be very great indeed. It's OBVIOUS that direct tachyon communication can't
send messages back in time to disrupt the continuum (by tachyon energy analysis),
so I don't know how some authors of physics textbooks will react, particularly the
ones I will reference as examples of those in error :-)

[Prokaryotic Capase Homolog]

On Wednesday, October 7, 2020 at 9:58:13 AM UTC-5, Gary Harnagel wrote:

> BTW, my major writings have been published in peer-reviewed letters and journals.
> In fact, I have reviewed papers for publishing. Not surprising since when an author
> references a paper, the authors referenced are in danger of becoming peer reviewers.

When I was in academia, many years ago, I published six papers and contributed a
chapter in a book before being awarded my Ph.D., which I just bound together and
submitted for my dissertation. Easiest dissertation ever, since I didn't have to
write anything except "glue" paragraphs between the chapters.

That doesn't count papers AFTER my Ph.D., of which there were a fair number before
I left academia for better-paying jobs.

...and yes, I've reviewed papers...

So don't think I'm impressed.

[coea...@gmail.com]

On Wednesday, October 7, 2020 at 7:34:18 AM UTC-7, Gary Harnagel wrote:
> > You seem to agree that signals can't go in the negative time direction
> > of an inertial coordinate system,
>
> Irrelevant.

It's very relevant, in view of:

> > *every* putative superluminal signal goes in the negative time
> > direction of some system of inertial coordinates,
>

> I DO realize that.

So, you agree that a signal cannot go in the negative time direction of a system of inertial coordinates, and you realize that *every* putative superluminal signal goes in the negative time direction of a system of inertial coordinates, so superluminal signals are not possible.

[Gary Harnagel]

On Wednesday, October 7, 2020 at 9:39:51 AM UTC-6, coea...@gmail.com wrote:
>
> On Wednesday, October 7, 2020 at 7:34:18 AM UTC-7, Gary Harnagel wrote:
> >
> > > You seem to agree that signals can't go in the negative time direction
> > > of an inertial coordinate system,
> >
> > Irrelevant.
>
> It's very relevant, in view of:
> > > *every* putative superluminal signal goes in the negative time
> > > direction of some system of inertial coordinates,
> >
> > I DO realize that.
>
> So, you agree that a signal cannot go in the negative time direction of a system
>of inertial coordinates,

You DO seem to have trouble parsing sentences.

> and you realize that *every* putative superluminal signal goes in the negative
> time direction of a system of inertial coordinates, so superluminal signals are
> not possible.

So you just go down a list: First you misrepresent what happens in a two frame
hand-off thought experiment and loudly proclaim, "See? FTL is impossible!"

Then when you're shown the error you made, you say, "Well, SOMEONE watching
them sees causality reversed. So FTL is impossible!"

Well, that's a mistake, too. You DO realize each looky loo observer has minions
at rest with him everywhere, right? They're the one's that report the so-called
"causality violation," right? These were right beside A and B and C and D, right?

So they're too stupid to READ the clocks of A, B, C and D and note that THEY didn't
see any causality violation? I guess you just can't find good minions these days.
Their conclusions should go right down the dumper where they belong.

[Gary Harnagel]

My, aren't we getting snippy :-)

Fortunately, I haven't reviewed very many papers. They're a pain in the neck.

So what was your major?

[coea...@gmail.com]

On Wednesday, October 7, 2020 at 10:28:00 AM UTC-7, Gary Harnagel wrote:
>>>> You seem to agree that signals can't go in the negative time
>>>> direction of an inertial coordinate system,
> > >
> > > Irrelevant.
> >

> > So, you agree that a signal cannot go in the negative time direction of

> > a system of inertial coordinates...

>
> You DO seem to have trouble parsing sentences.

To be clear, do you agree that a signal can't go in the negative time direction of any inertial coordinate system? This is the key question, since you've explicitly agreed that every putative superluminal signal goes in the negative time direction of an inertial coordinate system. Consequently, if you agree that a signal cannot go in the negative time direction of a system of inertial coordinates, it follows that superluminal signals are not possible.

On the other hand, if you claim that the laws of physics permit a signal to be sent in the negative time direction of an inertial coordinate system, then by the principle of relativity the laws of physics permit a signal to be sent in the negative time direction of any other system of inertial coordinates, which leads to the (false) ability to construct causal loops, as per the single-sentence reductio ad absurdum proof given earlier.

[Gary Harnagel]

On Wednesday, October 7, 2020 at 11:52:06 AM UTC-6, coea...@gmail.com wrote:
>
> On Wednesday, October 7, 2020 at 10:28:00 AM UTC-7, Gary Harnagel wrote:
> >
> > You DO seem to have trouble parsing sentences.
>
> To be clear, do you agree that a signal can't go in the negative time direction of any
> inertial coordinate system?

The only two that are relevant are the ones engaged in completing the loop. Everyone
else is irrelevant.

> This is the key question, since you've explicitly agreed that every putative superluminal
> signal goes in the negative time direction of an inertial coordinate system.

Actually, you completely misunderstand the dynamic properties of tachyons and that
relativistic velocity composition applies to them.

If u = 10c in a given frame, anyone moving at v wrt that frame will see the velocity as

u' = (u - v)/(1 - uv/c²) = (10c - v)/(1 - 10v/c)

If v = 0.1c, u' becomes infinite, which means it has no energy wrt that moving frame,
which means it's undetectable. So the moving observer can only detect it if he's
moving at v < 0.1c.

What happens if v = -0.9c? Then u' = 10.9c/(1 + 9) = 1.09c.

> Consequently, if you agree that a signal cannot go in the negative time direction of
> a system of inertial coordinates, it follows that superluminal signals are not possible.

It's irrelevant because tachyons can only be detected if they have positive energy.
The "negative time" assertion is synonymous with tachyons not having positive energy.

> On the other hand, [regurgitated misunderstanding deleted]

The observers who can't detect the tachyons can still interrogate their minions and
determine that they would claim (according to their clocks) that a result happened
before a cause. But how would they know what was the result and what was the
cause? By asking the stationary observers, of course, who would tell them that
according to their clocks, there was no causality violation. So if you take the word
of a bunch of looky loos, you can believe there was a causality violation. But you
would be stupid to do that.

[Dono.]

On Wednesday, October 7, 2020 at 1:26:15 PM UTC-7, hit...@yahoo.com wrote:
> So if you take the word
> of a bunch of looky loos, you can believe there was a causality violation. But you
> would be stupid to do that.

And just like that, dumbestfuck master crank Gary Harnagel denies PoR once again.

[Tom Roberts]

On 10/7/20 9:34 AM, Gary Harnagel wrote:
> A true causality violation occurs
> when a message is sent back into the past and is returned to the sender before he
> sent it, and that can only be done in the two frames directly involved with making
> that (purportedly) happen.

Here I explicitly prove that for any tachyonic signal with speed greater
than c there are always simple scenarios in which a "true causality
violation" occurs.

I use no Minkowski diagrams, as there are too many
quibbles about them. This is an algebraic proof based
on Lorentz transforms between inertial frames. I do
not know why none of the major participants in this
thread have not done this, as it is definitive.
This is, of course, a gedanken.

Consider inertial frames S and S' with coordinates (x,y,z,t) and
(x',y',z',t'), having parallel x/x' axes with S' moving in the +x
direction with speed v relative to S; ignore y,z,y',z'. Arrange the
coordinates so x=0,t=0 coincides with x'=0,t'=0. Let g=1/sqrt(1-v^2) and
L be a positive distance. Let w be the speed of the tachyonic signal
relative to the inertial frame in which the transmitter and receiver are
at rest. Use units with c=1, so 0<v<1 and w>1.

At x=0,t=0 a transmitter at rest in S sends a tachyonic signal in the +x
direction, which is received at x=L,t=L/w by a receiver at rest in S.

We have pre-arranged a transmitter at rest in S' to coincide with
x=L,t=L/w, so the receiver in S can instantly send a normal signal to
this transmitter in S' over zero distance. The transmitter in S'
immediately sends a second tachyonic signal in the -x' direction. That
signal was clearly sent at:
x' = g(x - v t) = g L - g v L/w
t' = g(t - v x) = g L/w - g v L
In passing note the following:
* x' > 0 (as expected)
* if 1/w > v: t'>0 and there can be no causality violation.
* if 1/w < v: t'<0 and the analysis continues; this
condition always applies in the limit v -> 1.
* for the example used in this thread (w=10,v=0.5), t' is
clearly negative.
* For the case 1/w < v: if one claims that no signal can
ever be sent in the negative time direction relative to
any inertial frame, that claim is already violated, as
in S' the signal was sent at t'=0 and gets to the S'
transmitter at t'<0.

We have also pre-arranged a receiver at rest in S' to coincide with x=0
when it receives that second tachyonic signal. It will immediately send
a normal signal over zero distance to the transmitter in S, completing a
causal loop -- the question is: does it arrive at t>0 (causality OK), or
t<0 (causality violation)?

Use (X',T') for the coordinates of the second tachyonic signal in S',
and compute (X',T') such that the receiver is located at x=0.

The second tachyonic signal propagates in S' as a function of T':
X' = (g L - g v L/w) - w (T' - (g L/w - g v L))
[This is just a linear trajectory in the -x' direction
starting at the S' coordinates given above.]
The condition for the receiver to be located at x=0 is:
0 = x = g(X' + v T')
Solving these two equations in two unknowns (X',T') gives:
T' = (2 g L - g v L/w - g w v L) / (w - v)
X' = -v T'

Now we can calculate the arrival time T of the signal back at the
transmitter in S (at x=0):
T = g(T' + v X') = g T' (1 - v^2) = T'/g
= [L/(w-v)] (2 - v/w - w v)
As w>v and L>0, the factor in brackets is positive so the sign of T is
sign(T) = sign(2 - v/w - w v)
This means that for any value of w greater than 1 there is a range of v,
2/(1/w+w)<v<1, for which T<0 and causality is violated.

For the example in this thread with w=10: 0.198<v<1,
which includes the example's v=0.5.

Thus, for any tachyonic signal with speed greater than c relative to an
inertial frame, there are simple scenarios in which a "true causality
violation" occurs. It is also true that for such a signal there are
inertial frames in which it propagates in the negative time direction.
Both of those imply that such tachyonic signals are incompatible with SR
and causality.

Tom Roberts

[coea...@gmail.com]

On Wednesday, October 7, 2020 at 1:26:15 PM UTC-7, Gary Harnagel wrote:
> > To be clear, do you agree that a signal can't go in the negative time
> > direction of any inertial coordinate system?
>
> The only two that are relevant are the ones engaged in completing the
> loop.

I ask again: Is it possible for a signal to go in the negative time direction of an inertial coordinate system?

This is the key question, since you've explicitly agreed that every putative superluminal signal goes in the negative time direction of an inertial coordinate system, so if you agree that such backward-in-time signals are impossible, it rules out superluminal signaling.

> The observer can only detect it if he's moving at v < 0.1c.

Relative to what? The transmitter? If so, then A can send a signal to B at 10c in terms of their mutual rest frame, and D can send a signal at 10c to C in terms of their mutual rest frame. This leads to the causal loop as shown before.

[If, to the contrary, you are saying the ability of a receiver to detect a signal depends on the receiver's speed not relative to the transmitter but relative to some arbitrary third object that is not involved in the transmission or reception at all, then you're not making any sense, so I'll assume (unless you say otherwise) that this is not what you mean.]

> If u = 10c in a given frame, anyone moving at v wrt that frame will see

> the velocity as...

In the standard text-book proof, the receiver and transmitter are both stationary in the frame in which the putative superluminal signal propagates at speed 10c. So the speed of the signal is 10c in terms of each of their respective rest frames, because they are mutually at rest. (The infinitely many speeds that these two objects have relative to the infinitely many other objects in the universe, none of which are involved in this transmission, are obviously irrelevant.) Remember, the equations of physics take exactly the same form in terms of every system of inertial coordinates (principle of relativity).

[Tom Roberts]

On 10/7/20 3:26 PM, Gary Harnagel wrote:
> The only two [inertial frames] that are relevant are the ones

> engaged in completing the loop. Everyone else is irrelevant.

The proof I just posted conforms to this.

> Actually, you completely misunderstand the dynamic properties of
> tachyons and that relativistic velocity composition applies to them.

The proof that I just posted needs no assumption about velocity
composition of tachyon signals.

> It's irrelevant because tachyons can only be detected if they have
> positive energy.

The proof I just posted uses only tachyons that are detected in the same
frame from which they were emitted, so they have whatever energy they
were emitted with; it does not use their energy in any way.

> The "negative time" assertion is synonymous with tachyons not having
> positive energy.

Not true of the proof I just posted. It demonstrates that for any
tachyon signal traveling with speed > c there is always a simple
scenario in which the signal arrives at its source before it was emitted
(i.e. "negative time"). It does not use their energy in any way.

> [...]

The proof I just posted shows that a "true causality violation" [Gary
Harnagel] occurs in some scenarios for any tachyonic signal traveling
with speed > c relative to the inertial frame of its transmitter and
receiver.

Tom Roberts

[Dono.]

On Wednesday, October 7, 2020 at 1:36:50 PM UTC-7, tjrob137 wrote:
>
> sign(T) = sign(2 - v/w - w v)
> This means that for any value of w greater than 1 there is a range of v,
> 2/(1/w+w)<v<1, for which T<0 and causality is violated.
>

Nice analysis. Small correction: 2 - v/w - w v<0 for all w,v positive, so your proof is actually more general than you posted.

[Gary Harnagel]

From the perspective of S', the tachyon signal is launched at t' = 0
and is received at t' = γ(L/w + vL/c²). Even if w approaches infinity,
∆t' > γvL/c², which means w' < c²/v. ∆t = 0.

So the second tachyon signal is launched from x' = γL at t' = γvL/c²,
at the earliest, so it will arrive back at x = 0 at t' = γvL/c² at the earliest.
t = vL/c², so the total roundtrip time is ∆t = vL/c² in the stationary frame
and ∆t' = γvL/c² in the moving frame.

I don't get any ∆t or ∆t' negative, so what am I doing wrong?

[Dono.]

On Wednesday, October 7, 2020 at 7:18:54 PM UTC-7, hit...@yahoo.com wrote:

> I don't get any ∆t or ∆t' negative, so what am I doing wrong?

You are incapable to use the Lorentz transforms correctly. Just like you are inacpable of using the Minkowski diagrams correctly. Face it , Gary, you are an imbecile.

[Gary Harnagel]

Oops! I see what I did wrong. That should be t' = γ(L/w - vL/c²)

So unless w < c²/v, ∆t' < 0.

Back later ....

[Dono.]

On Wednesday, October 7, 2020 at 7:27:38 PM UTC-7, hit...@yahoo.com wrote:
>
> Oops! I see what I did wrong. That should be t' = γ(L/w - vL/c²)
>
> So unless w < c²/v, ∆t' < 0.
>
> Back later ....

Your goose is cooked , Gary. Just stop embarrassing yourself and admit you have been wrong all along.

[Ufonaut]

Consider a "stationary" rod of length L has synchronised clocks at each end, and one end has a tachyon emitter, the other end a receiver. If at time t=0 an emitter emits a (near-)infinite speed tachyon, the receiver will receive it at (approx) time t=0.

What this actually means is that if the emitter emits a (near-)infinite speed tachyon when it's clock is reading t=0, the receiver will receive it when its clock is reading (approx) t=0. Those clock readings are facts (not frame-dependant variables) that every observer in every frame can see for themselves - or, of course, the emitter and receiver can broadcast their clock readings to any interested parties (or "minions" :-) ) in any frame at any time.

Effectively, that's what "(near-)infinite speed " MEANS - the travel time is effectively 0, so the receiver's clock reads (approx) the same as the emitter.

So let's look at your "Figure 4 : Correct Minkowski Diagram" at https://vixra.org/pdf/1908.0306v1.pdf , which algebraically you have agreed as below :

On Wednesday, October 7, 2020 at 12:10:56 AM UTC+10, hit...@yahoo.com wrote:
> On Tuesday, October 6, 2020 at 3:44:19 AM UTC-6, prokaryotic.c...@gmail.com wrote:

> > In Figure 4-4,
> > D at (x,t) = (L,vL/c²) transforms to (x',t') = (L/γ,0)
> > C at (x,t) = (v²L/c², vL/c²) transforms to (x',t') = (0,vL/(γc²))
> Yep, that's what I got, too. See above.
> > After scaling the "L" in your calculations above by a factor of gamma, it is
> > apparent that in figure https://tinyurl.com/yy5tugup, you believe that a
> > superluminal signal emitted from object D at (x',t') = (L,0) crosses
> > horizontally to meet up with object C at point (x',t') = (0,vL/c²)
> Yep, that's why C can't hand-off the message to A and why P is necessary.

So you have D emitting a (near-)infinitely fast tachyon when his clock reads t'D=0, and according to you this will be received by C at t'C = vL/c².

To be clear again what you are saying here : you are saying that when C receives the tachyons from D, then C's clock (that has been synchronised with D's clock) will be reading vL/c². Likewise, P's clock will also be reading roughly the same (certainly > 0). As above for the rod, D's, C's and P's clock readings at these events are NOT frame dependant, but will be agreed by all (eg each of them can broadcast their clock readings to all).

That difference in clock readings between t'D and t'C is the time taken ACCORDING TO THE PRIMED-DCP-FRAME for the tachyon's D-to-C trip. That difference = t'C - t'D = vL/c² ACCORDING TO THE PRIMED-DCP-FRAME.

The thing is, BY DEFINITION a trip that takes time vL/c² > 0 is NOT infinite speed.

In other words, you are contradicting the initial premise of D being able to emit an infinitely fast tachyon (or at 10c tachyon ), as well as your earlier statements that any frame (such as the primed-DCP frame) can send tachyons at any speed between emitter and receiver both at rest in that frame.

Your justification for this is your acceptance of the "snapshots of spacetime" image of http://www.pitt.edu/~jdnorton/teaching/HPS_0410/chapters/spacetime/index.html

Your assertion seems to be based on the idea that time marches equally and inexorably upwards through that stack, from "earlier" to "now" to "later" for ALL frames - ie when at "now", that "earlier" layer belongs to "the dead past" that no other frames can "access".

To me, that is the clearest demonstration of "the block universe" concept that I reject.

Trouble is, Norton's image is the perspective of ONE frame; RoS means other frames equally have their own "stacks" of spacetime, that are "tilted" relative to that one. There is no "dead past", but each frame can "access" whatever is allowed according to their own "stack".

[Ross A. Finlayson]

Does the Batavia/Baikal neutrino-phone pick up more or less right on time?

[Ufonaut]

On Thursday, October 8, 2020 at 2:08:58 PM UTC+10, Ross A. Finlayson wrote:
> Does the Batavia/Baikal neutrino-phone pick up more or less right on time?

The Bat-Phone is always answered right on time :-)
https://www.flickr.com/photos/batman-and-robin/33370727832

[Gary Harnagel]

On Wednesday, October 7, 2020 at 8:18:54 PM UTC-6, Gary Harnagel wrote:
>

and is received at t' = γ(L/w - vL/c²). This is why I believe it makes
sense to limit w to c²/v. The reason for this will be discussed later.

Thus if w = c²/v, ∆t = vL/c² and ∆t' = 0.

So the second tachyon signal is launched from x' = γL at t' = 0, at
the earliest, but t' at t = (0,vL/c²) is t' = γvL/c², so let's call the
velocity of the return tachyon signal u and u' = -c²/v. So u = -∞.

So the total roundtrip time is ∆t = vL/c² in the stationary frame

and ∆t' = γvL/c² in the moving frame.

If w actually reached c²/v, the tachyon energy would reach zero and
would be undetectable by an observer in the moving frame, but they
would conclude an effect happened before its cause. Is this really
a problem? A subject for future discussion.

If w = ∞, and u' = -c²/v (u = -∞), the roundtrip time would be zero in
both frames. That doesn't violate causality, but it's inconsistent with
direct tachyon communication between moving observers.

Limiting w to c²/v makes this method consistent with the direct method.
That may be important.

[Dono.]

On Wednesday, October 7, 2020 at 9:52:44 PM UTC-7, hit...@yahoo.com wrote:
>
> From the perspective of S', the tachyon signal is launched at t' = 0
> and is received at t' = γ(L/w - vL/c²). This is why I believe it makes
> sense to limit w to c²/v. The reason for this will be discussed later.
>

You can't , dishonest dumbfuck. You get the causality violations for w>c^2/v. You can't even tie the speeds of the tachyons to the relative speed between frames, "v". There is no reason for that limitation. Except your desperate dishonesty. You and your "theory" are cooked.

[Ross A. Finlayson]

Einstein-Lorentz-Fitzgerald is for a supergravity theory after GTR.

Actually putting the supergravity up front ("modern fall gravity")
kind of is like where the organization before was SR makes GR,
that these days GR makes SR and SR is local, and that GR makes
supergravity, would then follow later that supergravity makes GR.

[Ross A. Finlayson]

"This section is treated as a classical Higgs field. " -- https://en.wikipedia.org/wiki/Supermetric

... which IS a field, the classical Higgs field, which is a field,
not the "Higgs field" which is not.

Super-symmetry breaking in the theory (for, symmetry-flex), is either way, in the theory,
where of course that always in the theory without it, it's only ever one way.

Of course anybody knows that Higgs boson is both last inside Standard Model
and first outside Standard Model, and has a big divot in it.

Big divot.

[Prokaryotic Capase Homolog]

As I have repeatedly emphasized in this thread, the formula relating how signals
are passed between two objects at rest within an observational frame of reference
cannot be dependent on "v", otherwise one has a means within the frame for
determining v, with a violation of the PoR.

[Gary Harnagel]

On Thursday, October 8, 2020 at 2:38:34 AM UTC-6, prokaryotic.c...@gmail.com wrote:
>
> As I have repeatedly emphasized in this thread, the formula relating how signals
> are passed between two objects at rest within an observational frame of reference
> cannot be dependent on "v", otherwise one has a means within the frame for
> determining v, with a violation of the PoR.

But to effect a hand-off between frames, v IS important for where receivers and
transmitters are located. For example, given xA = 0 and xB = L , at rest in S, and
observer D moving at v wrt S, and xD = L/γ² at t = 0. If A initiates a tachyon pulse
at velocity w at t = 0, then in order for B to hand-off to D, w must equal c²/v.

Of course, you can specify different initial conditions, say xD = L at t = 0, then
A must send the tachyon pulse at w = ∞. D can't detect the pulse directly (because
the tachyon energy isn't positive), but B can still hand off the "message" to D (at
tD' = -γvL/c²). So what can D do with that message?

Can he send it to C infinitely fast so it arrives at C at tC' = -γL/c²? We're still observing
this from the S frame, where t = 0. So if C can pass it to A then xC = 0, but if xC = 0
when t = 0, tC' = 0 also. So D must send it at u' = -c²/v ( u = ∞).

So v comes into a speed limit in both scenarios.
.

[coea...@gmail.com]

On Thursday, October 8, 2020 at 9:07:04 AM UTC-7, Gary Harnagel wrote:
> > To be clear, do you agree that a signal can't go in the negative time
> > direction of any inertial coordinate system?
>

> The only two that are relevant are the ones engaged in completing the
> loop.

I ask again: Is it possible for a signal to go in the negative time direction of an inertial coordinate system?

This is the key question, since you've explicitly agreed that every putative superluminal signal goes in the negative time direction of an inertial coordinate system, so if you agree that such backward-in-time signals are impossible, it already rules out superluminal signaling.

> The observer can only detect it if he's moving at v < 0.1c.

Relative to what? The transmitter? If so, then A can send a signal to B at 10c in terms of their mutual rest frame, and D can send a signal at 10c to C in terms of their mutual rest frame, leading to the causal loop as shown before, which rules out superluminal signaling.

If, to the contrary, you are saying the ability of a receiver to detect a signal depends on the receiver's speed not relative to the transmitter but relative to some arbitrary third object that is not involved in the transmission or reception at all, then you're not making any sense, so I'll charitably assume (unless you say otherwise) that this is not what you mean.

> If u = 10c in a given frame, anyone moving at v wrt that frame will see
> the velocity as...

In the standard text-book proof, the receiver and transmitter are both stationary in the frame in which the putative superluminal signal propagates at speed 10c. So the speed of the signal is 10c in terms of each of their respective rest frames, because they are mutually at rest.

The infinitely many speeds that these two objects have relative to the infinitely many other objects in the universe, none of which are involved in this transmission, are obviously irrelevant. Remember, the equations of physics take exactly the same form in terms of every system of inertial coordinates (principle of relativity).

You've been given the one-sentence text-book explanation of why the putative ability to send superluminal signals would imply causal loops, and the explanation is iron-clad and irrefutable. You've not even attempted to provide any rebuttal.

[Dono.]

On Thursday, October 8, 2020 at 9:07:04 AM UTC-7, hit...@yahoo.com wrote:

> So v comes into a speed limit in both scenarios.
>

You are reaching new lows, Harnagel.

[Gary Harnagel]

On Thursday, October 8, 2020 at 11:12:42 AM UTC-6, coea...@gmail.com wrote:
>
> On Thursday, October 8, 2020 at 9:07:04 AM UTC-7, Gary Harnagel wrote:
> >
> > > To be clear, do you agree that a signal can't go in the negative time
> > > direction of any inertial coordinate system?
> >
> > The only two that are relevant are the ones engaged in completing the
> > loop.
>
> I ask again: Is it possible for a signal to go in the negative time direction of an
> inertial coordinate system?

Since it becomes undetectable at infinite speed, your question makes no sense.

> This is the key question, since you've explicitly agreed that every putative
> superluminal signal goes in the negative time direction of an inertial coordinate
> system, so if you agree that such backward-in-time signals are impossible, it already
> rules out superluminal signaling.

You should have been a shyster lawyer.

> > The observer can only detect it if he's moving at v < 0.1c.
>
> Relative to what? The transmitter? If so, then A can send a signal to B at 10c in terms of
> their mutual rest frame, and D can send a signal at 10c to C in terms of their mutual rest
> frame, leading to the causal loop as shown before, which rules out superluminal signaling.

"When did you stop beating your wife?"

Your simplistic argument is misleading.

> If, to the contrary, you are saying the ability of a receiver to detect a signal depends on the
> receiver's speed not relative to the transmitter but relative to some arbitrary third object
> that is not involved in the transmission or reception at all, then you're not making any sense,

Even bringing such a stupid claim is nonsensical.

> so I'll charitably assume (unless you say otherwise) that this is not what you mean.

It's IOTTMCO that v was wrt the transmitter, DUH!

> > If u = 10c in a given frame, anyone moving at v wrt that frame will see
> > the velocity as...
>
> In the standard text-book proof, the receiver and transmitter are both stationary in the frame
> in which the putative superluminal signal propagates at speed 10c. So the speed of the
> signal is 10c in terms of each of their respective rest frames, because they are mutually at rest.
> The infinitely many speeds that these two objects have relative to the infinitely many other
> objects in the universe, none of which are involved in this transmission, are obviously
> irrelevant.

Tom showed us that with w = 10c, no causality violation occurred. Didn't you notice?
But there's still a problem when w > c²/v which wasn't addressed. I addressed it previously,
but it went right over your head.

> Remember, the equations of physics take exactly the same form in terms of every system
> of inertial coordinates (principle of relativity).

So what equations do you have heartburn over?

> You've been given the one-sentence text-book explanation of why the putative ability to
> send superluminal signals would imply causal loops, and the explanation is iron-clad and
> irrefutable. You've not even attempted to provide any rebuttal.

We've all been given simplistic lawyerese which deceives the lawyer :-)

Let's take a scenario with standard transmitters and receivers A, B, C, and D. A and B are
at rest in S at xA = 0 and xB = L, with moving transmitters and receivers at xC' = 0, xD' = γL,
tC' = 0 and tD' = -γvL/c² at t = 0.

At t = 0, A sends a tachyon pulse to B at w = ∞. It arrives at t = 0. B hands it off to D at
tD' = -γvL/c². If D sends it to C at u' = -∞, can C pass it immediately to A?

No, because they weren't adjacent then. D can send it to C at u' = -c²/v so it arrives at
tC' = 0. Then C can hand it off to A. Roundtrip time is ∆t = 0. BUT ...

There's a different scenario that makes a little more sense. It presumes w = c²/v. Of
course, at t = 0, xC and xD would be at -v²L/c² and L/γ², respectively. Then the roundtrip
time would be ∆t = vL/c² (∆t' = γvL/c²).

This result is consistent with direct tachyon communication and neither tachyon signal
"goes back in time" in the two frames involved with the hand-off. As I said before, most
moving looky loos wouldn't see the tachyon signals. aren't part of the process, and can't
use any information gleaned to create a paradox anyway, so what they conclude is irrelevant.

[Dono.]

On Thursday, October 8, 2020 at 3:30:47 PM UTC-7, hit...@yahoo.com wrote:

> Tom showed us that with w = 10c, no causality violation occurred. Didn't you notice?
> But there's still a problem when w > c²/v which wasn't addressed. I addressed it previously,

No, you didn't, you have simply sunk into your own morass of lies and imbecilities even deeper.

[Tom Roberts]

On 10/7/20 11:52 PM, Gary Harnagel wrote:
> I believe it makes
> sense to limit w to c²/v.

That makes ABSOLUTELY NO SENSE -- w and v are completely independent
parameters with VERY different meanings.

The premise is that tachyonic signals might be physical phenomena with
speed w (> c). But physical phenomena cannot possibly be dependent on
any aspect of coordinate systems, including v (the ARBITRARY relative
speed between a pair of inertial coordinate systems).

For any w > c, there is a simple scenario in which a "true causality
violation" occurs, and there are inertial frames in which such a
tachyonic signal propagates backwards in time. These make discussions of
tachyons useless, until and unless they are observed experimentally.

Tom Roberts

[coea...@gmail.com]

On Thursday, October 8, 2020 at 3:30:47 PM UTC-7, Gary Harnagel wrote:
> > Is it possible for a signal to go in the negative time direction of an
> > inertial coordinate system?
>
> Since it becomes undetectable at infinite speed, your question
> makes no sense.

To be clear, are you saying that a signal that propagates instantaneously (meaning at constant time coordinate) in terms of an inertial coordinate system cannot be detected?

If so, then no superluminal signal can be detected, because you've already agreed that every putative superluminal signal goes in the negative time direction of some inertial coordinates, and of course it goes in the positive time direction of others, and it goes in the constant time direction in one unique system of inertial coordinates (Relativity 101).

> The observer can only detect it if he's moving at v < 0.1c [with
> respect to the transmitter].

Great. So A can send a signal to B at 10c in terms of their mutual rest frame, and D can send a signal at 10c to C in terms of their mutual rest frame, leading to the causal loop as shown before, which rules out superluminal signaling.

> At t = 0, A sends a tachyon pulse to B at w = ∞.

No, you've already declared many times (including your current post) that an instantaneous signal cannot be detected, which is why I've been explaining things to you with putative superluminal signals of speed 10c in terms of the mutual rest frame of the transmitter and receiver.

Again, according to you, A can transmit a message to B at speed (say) 10c in terms of their mutual rest frame, and B can immediately transmit the message to D at speed 1c as they cross paths (with mutual speed c/2), and [according to you] D can immediately transmit the message to C at speed 10c in terms of their mutual rest frame, and C can immediately transmit the message to A at speed 1c as they cross paths. But this implies that the message is received by A from C prior to being transmitted by A, which entails a causal loop.

As you know, this standard text-book reasoning is iron-clad and irrefutable.

> If D sends it to C... can C pass it immediately to A? No, because they
> weren't adjacent then.

Yes they were. The initial conditions are such that C intersects with A at the event where the signal from D arrives at A.

[Tom Roberts]

On 10/7/20 4:06 PM, Dono. wrote:
> 2 - v/w - w v<0 for all w,v positive

That is not true: w=2,v=0.5 is just one counterexample to your claim.

The range for v that I gave, 2/(1/w+w)<v<1, is correct: given any w>1,
that range of v makes 2-v/w-v*w < 0, implying a causality violation.

The closer w is to 1, the larger is the lower bound on v:
if w=1.1, the range is 0.99547511<v<1
If w=10, the range is 0.1980198<v<1
If w=100, the range is 0.019998<v<1

Tom Roberts

[Tom Roberts]

On 10/8/20 5:30 PM, Gary Harnagel wrote:
> Tom showed us that with w = 10c, no causality violation occurred.

This is just plain wrong.

For w = 10c, in my scenario a causality violation occurs for any v in
the range 0.198c < v < c (restoring the c in my values).

I said that explicitly, and have no idea how you could misread so badly.

Tom Roberts

[Dono.]

Correct, I saw it as 2-v/w-v/w , missed the multiplication "*"

[Gary Harnagel]

So you picked a value for w of 10c (well, someone else used it first0).
Don't you agree that if 10c didn't work, 20c would be even worse?
What about 50c? 1000c? So in my thought experiments I go all out
and presume w = ∞. If that doesn't violate causality, then 10c won't either.

So first I considered this:

Let's take a scenario with standard transmitters and receivers A, B, C, and D. A and B are
at rest in S at xA = 0 and xB = L, with moving transmitters and receivers at xC' = 0, xD' = γL,
tC' = 0 and tD' = -γvL/c² at t = 0.

At t = 0, A sends a tachyon pulse to B at w = ∞. It arrives at t = 0. B hands it off to D at
tD' = -γvL/c². If D sends it to C at u' = -∞, can C pass it immediately to A?

No, because they weren't adjacent then. D can send it to C at u' = -c²/v so it arrives at
tC' = 0. Then C can hand it off to A. Roundtrip time is ∆t = 0.

Of course, C could receive it at tC' = -γvL/c² but would have to hang onto it until A is
adjacent to it (at t = 0). The net velocity would be -c²/v.

At v = 0.5c, u' = 2c, which any assumption of greater tachyon speed, such as -10c, wouldn't
change anything since the hand-off still coudn't happen until A and C were adjacent.
Do you see any errors in this analysis?

A modification of your thought experiment (tachyon speed different):

[Dono.]

On Thursday, October 8, 2020 at 7:15:38 PM UTC-7, hit...@yahoo.com wrote:
>
> There's a different scenario that makes a little more sense. It presumes w = c²/v. Of
> course, at t = 0, xC and xD would be at -v²L/c² and L/γ², respectively. Then the roundtrip
> time would be ∆t = vL/c² (∆t' = γvL/c²).

Dumbestfuck,

You don't get it: there is no physical reason to tie the speed of the tachyon "w" and the relative speed of the frames "v". You theory is cooked. And so are you.

[Tom Roberts]

On 10/8/20 9:15 PM, Gary Harnagel wrote:
> On Thursday, October 8, 2020 at 5:38:21 PM UTC-6, tjrob137 wrote:
>> On 10/8/20 5:30 PM, Gary Harnagel wrote:
>>> Tom showed us that with w = 10c, no causality violation occurred.
>> This is just plain wrong.
>> For w = 10c, in my scenario a causality violation occurs for any v in
>> the range 0.198c < v < c (restoring the c in my values).
>> I said that explicitly, and have no idea how you could misread so badly.
>

> So you picked a value for w of 10c (well, someone else used it first0).
> Don't you agree that if 10c didn't work, 20c would be even worse?

No value for w greater than c is "worse" or "better" -- ALL OF THEM
imply a "true causality violation" [YOUR words]. It's just that a larger
value for w permits smaller values of v to display that causality
violation; for EVERY value of w > c there is a range of values of v that
do so: 2c/(c/w+w/c)<v<c.
if w=1.1c, the range is 0.99547511c<v<c
If w=10c, the range is 0.1980198c<v<c
If w=100c, the range is 0.019998c<v<c
In the limit w->infinity, the range is 0<v<c

> [...] the hand-off still coudn't happen until A and C were adjacent.

While I did not label tachyon endpoints as you did, in my scenario I
EXPLICITLY computed where to place the receiver in S' so when it
receives the tachyon signal it is adjacent to the initial transmitter in
S (i.e. x=0), specifically so the ordinary hand-off could be performed.

> There's a different scenario that makes a little more sense. It presumes w = c²/v.

That makes NO "sense". A physical phenomenon like tachyon signaling
cannot possibly depend on a coordinate relationship like v. You are
expecting the tachyon to be CLAIRVOYANT, and magically "know" BEFORE IT
IS EMITTED how fast S' will be traveling relative to S -- THAT IS NONSENSE.

Remember that in my scenario the tachyon transmitter
and receiver are at rest in a single inertial frame.

Tom Roberts

[coea...@gmail.com]

On Thursday, October 8, 2020 at 3:30:47 PM UTC-7, Gary Harnagel wrote:

> [A signal] becomes undetectable at infinite speed...

To be clear, you are now saying that a signal that propagates instantaneously (meaning at constant time coordinate) in terms of an inertial coordinate system cannot be detected. It follows that *no* superluminal signal can be detected, because every putative superluminal signal goes in the constant time direction in a system of inertial coordinates.

> The observer can only detect it if he's moving at v < 0.1c [with
> respect to the transmitter].

Then you have no objection to the standard textbook proof, in which the putative superluminal signals are between transmitters and receivers that are mutually at rest.

> At t = 0, A sends a tachyon pulse to B at w = ∞.

You contradict yourself, because you've already declared many times (including your current post) that an instantaneous signal cannot be detected, which is why I've been explaining things to you with putative superluminal signals of speed 10c in terms of the mutual rest frame of the transmitter and receiver.

> If D sends it to C... can C pass it immediately to A? No, because they
> weren't adjacent then.

Yes they were. The initial conditions are such that C intersects with A at the event where the putative superluminal signal from D would arrive at C. Of course, no signal will actually arrive, because superluminal signals are impossible. That's what this proof demonstrates, i.e., it shows that IF it were possible to send the claimed superluminal signals between mutually resting transmitter and receiver, then in the context of special relativity we could construct this causal loop.

[Gary Harnagel]

On Thursday, October 8, 2020 at 10:36:22 PM UTC-6, tjrob137 wrote:
>
> On 10/8/20 9:15 PM, Gary Harnagel wrote:
> >
> > So you picked a value for w of 10c (well, someone else used it first0).
> > Don't you agree that if 10c didn't work, 20c would be even worse?
>
> No value for w greater than c is "worse" or "better" -- ALL OF THEM
> imply a "true causality violation" [YOUR words]. It's just that a larger
> value for w permits smaller values of v to display that causality
> violation;

Yes, but for a given v, a larger tachyon speed would produce a more negative
purported ∆t.

> > [...] the hand-off still coudn't happen until A and C were adjacent.
>
> While I did not label tachyon endpoints as you did, in my scenario I
> EXPLICITLY computed where to place the receiver in S' so when it
> receives the tachyon signal it is adjacent to the initial transmitter in
> S (i.e. x=0), specifically so the ordinary hand-off could be performed.

Yes, I see! I was assuming a laboratory setup where xC = -v(1/w - 1/u) + vt
so that at t = L(1/w - 1/u), xC = 0 (where u is negative).

The tachyon signal gets to L at t = L/w. The time in the entire S frame is
then t = L/w. The tachyon transmitter (with an em receiver) at x = 0 is
also at t = L/w.

The question is, can a tachyon signal in the S' frame (call its velocity u',
where u' is negative) have a velocity, u, in S such that it arrives at x = 0
BEFORE t = L/w - L/u?

By picking v = 0.5c and u' = -10c, you're assuming that the past actually,
physically exists and is accessible from the present ( t = L/w). This
NEVER happens with transmitter and receiver at rest with each other.
In fact, it NEVER happens with direct tachyon communication between
moving transmitters and receivers. And in fact it doesn't happen when
a moving transmitter (v relative to the stationary observer) emits a
tachyon signal at w' (both v and w' positive.

The ONLY time it is purported to happen is when v and w' are in opposite
directions. That should give one pause.

“No, no, you’re not thinking: you’re just being logical” – Niels Bohr

> > There's a different scenario that makes a little more sense. It presumes
> w = c²/v.
>
> That makes NO "sense". A physical phenomenon like tachyon signaling
> cannot possibly depend on a coordinate relationship like v.

Well, actually it does. Given v and w' positive (tachyon transmitter in S'),

w = (w' + v)/(1 + w'v/c²)

so the observed tachyon velocity in S does indeed depend on v. In fact,
as w' approaches infinity, w approaches c²/v.

> expecting the tachyon to be CLAIRVOYANT, and magically "know" BEFORE IT
> IS EMITTED how fast S' will be traveling relative to S -- THAT IS NONSENSE.

Simple relativistic velocity composition :-)

> Remember that in my scenario the tachyon transmitter
> and receiver are at rest in a single inertial frame.
>
> Tom Roberts

As a laboratory physicist, I see this:

t = 0:
C_____________________D xC = -vL(1/w - 1/u) + vt, tC' = -γ(v xC/c²)
________A_________________B
________T --> w


t = L/w:
____C_____________________D tD' = γ(L/w - vL/c²)
________A_________________B
__________________________T

t = L/w - L/u:
________C_____________________D tC' = γL(1/w - 1/u)
________A_________________B
____u <--T_________________

u = (0 - L)/(L/w - L/u)

What you're saying is:

t = 0:
____________C_________D
________A_________________B
________T --> w

t = L/w:
________________C_________D
________A_________________B
__________________________T

t = -vL/c²
________C_________D
________A_________________B
_______POP!

No tachyon has been transmitted.
Ergo, D couldn't have sent the tachyon back to C at ANY speed.

[Gary Harnagel]

On Friday, October 9, 2020 at 8:43:40 AM UTC-6, coea...@gmail.com wrote:
>
> On Thursday, October 8, 2020 at 3:30:47 PM UTC-7, Gary Harnagel wrote:
> >
> > [A signal] becomes undetectable at infinite speed...
>

> [Blah, blah, blah]

>
> > The observer can only detect it if he's moving at v < 0.1c [with
> > respect to the transmitter].
>
> Then you have no objection to the standard textbook proof, in
> which the putative superluminal signals are between transmitters
> and receivers that are mutually at rest.
>
> > At t = 0, A sends a tachyon pulse to B at w = ∞.
>
> You contradict yourself, because you've already declared many times
> (including your current post) that an instantaneous signal cannot be
> detected, which is why I've been explaining things to you with putative
> superluminal signals of speed 10c in terms of the mutual rest frame
> of the transmitter and receiver.

OH GOOD GRIEF!!! I have explained previously that u = ∞ is an IDEALIZATION.
WHERE WERE YOU WHEN I STATED THAT? Now you come out of the
woodwork with THIS baloney?

> > If D sends it to C... can C pass it immediately to A? No, because they
> > weren't adjacent then.
>
> Yes they were.

Wrong. Look at my response to Tom Roberts.

[coea...@gmail.com]

On Friday, October 9, 2020 at 9:14:38 AM UTC-7, Gary Harnagel wrote:
> [A signal] becomes undetectable at infinite speed...

As you know, every putative superluminal signal has infinite speed in terms of some system of inertial coordinates, so your statement implies that every putative superluminal signal is undetectable.

> [blah blah blah]

That isn't a substantive response.

> The observer can only detect it if he's moving at v < 0.1c [with
> respect to the transmitter].

Then you have no objection to the standard textbook proof, in which the putative superluminal signals are between transmitters and receivers that are mutually at rest.

> At t = 0, A sends a tachyon pulse to B at w = ∞.

You contradict yourself, because just above in this very post you refused to respond to the simple and crucial question: "Is it possible for a signal to be sent in the negative time direction of an inertial coordinate system?" by saying that an instantaneous signal is undetectable. Now, as you know, every putative superluminal signal has infinite speed in terms of some system of inertial coordinates, so your statement implies that every putative superluminal signal is undetectable.

> If D sends it to C... can C pass it immediately to A? No, because they
> weren't adjacent then.

Again, we set the the initial conditions so that C intersects with A at the event where the putative superluminal signal from D would arrive at C. Of course, no signal will actually arrive, because superluminal signals are impossible. That's what this proof demonstrates, i.e., it shows that IF it were possible to send the claimed superluminal signals between mutually resting transmitter and receiver, then in the context of special relativity we could construct this causal loop. But this is actually superfluous now, because you've already stated that all putative superluminal signals are undetectable, since they are all instantaneous in terms of some system of inertial coordinates - in fact, they all go in the negative time direction of some systems of inertial coordinates.

[Prokaryotic Capase Homolog]

On Friday, October 9, 2020 at 12:52:14 PM UTC-5, coea...@gmail.com wrote:
> On Friday, October 9, 2020 at 9:14:38 AM UTC-7, Gary Harnagel wrote:
> > [A signal] becomes undetectable at infinite speed...
>
> As you know, every putative superluminal signal has infinite speed in terms of
> some system of inertial coordinates, so your statement implies that every putative
> superluminal signal is undetectable.

Gary -

The physics of a scenario does not change when observed in different reference
frames. If a superluminal signal cannot be transmitted from D to C when observed
from one reference frame, switching to a different reference frame will not
magically make transmission of the signal from D to C possible.

Coeal has made this simple and fundamental point perhaps a dozen times, but you
have chosen to ignore this point an equal number of times.

[Maciej Wozniak]

And what do you expect from your fellow
fanatic cultist?