Houston Feldhaus wrote:

> Gary Harnagel wrote:
>
>>> Funny that you can't do that "jumping frames" only with your tachyon
>>> model, but fine otherwise
>>
>> Perhaps you didn't notice that I completed the analysis from the
>> perspective of Alice and Bob, and then I did the analysis from the
>> perspective of Carol and Dave: t = 0: C --> v _______________ D --> v A
>> ________________________ B
>
> ohh really, that's just wondreful, now that the lemmings are gotten
> penetrated already.
>
> THE FDA WIL NOT AUTHORIZE OR APPROVE OF ANY COVID-19 VACCINE
> https://www.brighteon.com/280bd995-9736-424c-82da-ef68b224f298
>
> "we will never authorize any vaccines, disregard pressure".
>
> This makes the bill gates, the bidens, the trumpf and the boris johnsons
> et al, prone to getten arrested, by the executive powers in western
> democracies. Since that will never happen, civilian arrests mass scale
> is the default alternative.

Meant as "citizen's arrest"
https://en.wikipedia.org/wiki/Citizen%27s_arrest

A citizen's arrest is an arrest made by a private citizen – that is, a
person who is not acting as a sworn law-enforcement official.[1] In
common law jurisdictions, the practice dates back to medieval England and
the English common law, in which sheriffs encouraged ordinary citizens to
help apprehend law breakers

On Thursday, April 29, 2021 at 6:33:10 AM UTC-7, hit...@yahoo.com wrote:
> On Wednesday, April 28, 2021 at 10:54:48 PM UTC-6, Dono. wrote:
> >
> > On Wednesday, April 28, 2021 at 9:19:19 PM UTC-7, hit...@yahoo.com wrote:
> > >
> > > I started a thread BEFORE 8/29/19 announcing the paper.
> >
> > So, you posted the same crankeries in an eralier thread, must have missed it.
> No, I don't think you missed it. I think you "missed it" intentionally because it
> proves you didn't post the first criticism as you claimed.
>

I posted the first criticism to your posted crackpoterries in TWO different threads, 8/24 and 8/29.

> > you do things the same exact way as your fellow crank, David Seppala, Ed Lake,
> > Ken Shito, Keith RocksFerBrains, you open a crank thread, you take it in the chin,
> > you avandon the thread, wait for the people to forget about you and you open a
> > new thread . With the same exact crankerries. You never learn, Gary.
> The fact that each version of https://vixra.org/abs/1908.0306 ("Causality Between
> Events with Space-Like Separation") is different,

....means that you compounded the crankerries from one version into the next. Bottom line, version 3 is just as crank as it gets.

> Furthermore, the
> newer paper, https://vixra.org/abs/2011.0076 ("Tachyons from a Laboratory Perspective")

....is just as crank as the others

On Friday, April 30, 2021 at 12:38:39 AM UTC+10, hit...@yahoo.com wrote:
> On Thursday, April 29, 2021 at 7:20:35 AM UTC-6, Rob Acraman wrote:

> > Not if you're careful.
> My point is that you and just about everyone else wasn't careful when dealing with tachyon
> analysis.

And my point is it's the other way round ;) You have not been careful enough, resulting in you not realising that when you switch frames, you have also been switching realities.

Let's say that the trailing end of the pole has a light, that makes a SINGLE brief flash (maybe when it receives a tachyon message ;) ). We could even add somebody standing on the ground (so in the Barn frame) by the side of the light as it flashes - let's call that person L.

That flash MUST be EITHER :
Reality 1: BEFORE it enters the barn, besides Lenny
OR
Reality 2: AT/AFTER it entered the barn, besides Linda

Under standard SR, ALL frames will always agree on the single reality. BOTH Barn-Frame and Pole-Frame agree on Reality-1, or BOTH Barn-Frame and Pole-Frame agree on Reality-2. This is being careful, and is what allows "jumping frames".

If someone is NOT careful, they may end up with thinking that that light flashes (eg, receives a tachyon message) in Reality-1 for the Pole frame, but Reality-2 for the Barn frame - which of course would be a "big no-no", a contradiction.

With such a result, that someone may choose to impose arbitrary rules forbidding "jumping frames" - you either look at the Barn frame with Lenny, or the Pole frame with Linda. In fact, that someone may confuse things even more, and give that person L the SAME name in both realities - for example, using "Lenny" for both cases. That someone would then insist on discussing the Barn Frame with Lenny, THEN the Pole frame with "Lenny". After all this work, that someone could then mistakenly think that it is the one who wants to "jump frames" that has not been careful, whereas in fact it's the other way round.

The problem - the lack of care - is NOT with the person who wants to jump frames, but with the someone who wants to insist that Reality-1 and Reality-2 are the same reality.

> > Of course, can't do that "jumping frames" if you're using the two different frames to actually describe
> > two different (so contradictory) realities.
> >
> > Funny that you can't do that "jumping frames" only with your tachyon model, but fine otherwise ;)
> Perhaps you didn't notice that I completed the analysis from the perspective of Alice and Bob, and
> then I did the analysis from the perspective of Carol and Dave:

Yes, you did Reality-1 from frame S, then Reality-2 from S'.

>
> t = 0:
> C --> v _______________ D --> v
> A ________________________ B
>
> A and B are stationary a distance L apart. At t = 0 in the stationary frame,
> C is adjacent to A, but D hasn't made it to D yet.
>
> C is at x = 0 and the time on C's clock reads tC' = 0.
>
> At t = vL/c², B initiates a message and passes it to D at tD' = 0, and D sends
> it by tachyons to C:
>
> t = vL/c²:
> ___ C --> v _________ u' <---- D --> v
> A ________________________ B
>
> So can D send the signal to C at u' = infinity? After all, if we jump to the
> moving frame:
>
> t' = 0:
> ____ C ___________________ D
> v <-- A _______________ <--v B
>

Let's make the point here - according to standard non-FTL-non-Tachyon SR, this is EXACTLY the reality in the S' frame. There is NO contradiction, nor is there any "interference" from the AB frame. BOTH the S' and the S frames are equally, perfectly valid. Neither has ANY claim to being the "true" reality, or in mandating what is "The Dead Past".

Even if one of the frames was stationary wrt a lab.

>
> You DO make a point, though. From S (the "stationary" frame), it looks to
> Alice and Bob that Dave must send the signal to Carol at x = v²L/c², not to
> Carol at x = 0, which isn't in the snapshot. But when you jump frames to
> S', it looks to Dave that he CAN and MUST send the signal infinitely-fast
>
> Do you see a disconnect there? I sure do! That means to me that the scenario
> cannot be a valid representation of reality.

On that we agree ! Ooops, am I bisecting your comment ? Whoopsie ;)

First, because Alice and Bob claim
> the message loop cannot be completed while Carol and Dave think it can.

To be clear, that is only a contradiction for an FTL (such as a Tachyon) model.
Under standard non-FTL-non-tachyon SR, there is no problem : A,B,C and D all agree that the message loop cannot be completed.

>
> Second, if Dave sends the signal at u' = infinity, time goes backward in S.
> That violates causality, entropy and the arrow of time. This is what happens
> when jumping frames ... um ... "illegally."

Yes, which is why I say that Dave cannot send the signal at u' = infinity..

>
> When we do a COMPLETE analysis in one frame and THEN do a complete
> analysis in the other frame, we see the inconsistency, but when we do half
> in one frame and half in the other, we sail obliviously through to an invalid
> conclusion.

To take my Pole-Barn scenario earlier, if we do a COMPLETE analysis of Reality-1 in the Barn frame, THEN a complete analysis of Reality-2 in the Pole frame, we see the inconsistency. If we do half in one and half in the other, we can sail through to the conclusion that those are two different realities.

> > > > That is a problem with FTL, not with taking the time-slice of the coordinates.
> > >
> > > You say "FTL" without defining what you mean by that. You seem to mean a
> > > frame that's traveling FTL. Is that right? If so, that's not at all what I wrote.
> >
> > I meant whatever you meant when you referred to "has been done since FTL" :)
> My take is that tachyons don't reside in a "frame," meaning that observers can't
> go there, and there's a good reason for that. It's been hypothesized that charged
> tachyons would emit Cerenkov radiation, so tachyons must be UNCHARGED
> particles. It's hard to imagine how one could construct observers without
> protons and electrons :-)

Photons don't reside in a "frame" either.
Regardless, the point is getting a message (or "information") from (x, y, z, t1) to (other-x, other-y, other-z, t2) at faster-than-light speed. Whether that is tachyons, or what frame the messenger particles are in, or whatever really doesn't matter. The only thing that's important is that information "illegally" arriving at (other-x, other-y, other-z, t2).

> > > > > > One thing we never quite got clear in our previous discussions :
> > > > > >
> > > > > > Suppose Alice and Bob are in the same frame (so stationary wrt eachother), some
> > > > > > distance L apart from eachother, and of course they have synchronised their clocks.
> > > > > > At t=0, Alice sends Bob both a tachyon signal travelling at 10c, and a normal radio
> > > > > > signal. What time will Bob receive the tachyon signal ?
> > > > >
> > > > > If u = 10c, then ∆t = L/u, n'est-ce pas?
> > > >
> > > > ALWAYS ?? Regardless of other frames ??????????
> > >
> > > Other frames have nothing to do with ∆t. How could they? They would measure ∆t'.
> >
> > So other frames have nothing to do with the time that Bob's clock will be showing when
> > he receives the tachyon message.
> >
> > Great, I agree, so let's keep to that - so the ONLY frame that has been mentioned is the
> > one in which Alice and Bob are stationary.
> Now Rob, that's not true. Are you forgetting Carol and Dave in S'?

I had my Alice and Bob in this thread before you introduced yours ;-P

Yes, I had always intended my Alice and Bob to be the ones where we disagreed - where you say the messages could not be sent. In other words, the ones who you have just introduced and calling Carol and Dave - so OK, let's stick with those names.

So let's rephrase those earlier paragraphs with the Carol/Dave names, to see what you just agreed to :

Question: Dave and Carol are in the same frame S', distance L apart from eachother. At t=0, Dave sends Carol a tachyon signal travelling at 10c. What time will Carol receive that signal.

Your answer : If u = 10c, then ∆t = L/u, n'est-ce pas?

Me : ALWAYS ?? Regardless of other frames ??????????

Your answer: Other frames have nothing to do with ∆t. How could they?

Great, so you wholeheartedly agree that Alice and Bob passing by have absolutely NOTHING to do with what happens in the Carol/Dave frame. Specifically, Carol will receive the message in her frame (ie, her clock will be showing the time) of ∆t = L/u as you say. Of course, we said there that u = 10c, but for (near-)infinite-speed tachyons within that frame, that L/u becomes (near-)0 . Other frames like Alice/Bob's have nothing to do with it.

Gary Harnagel wrote:

> A and B are stationary a distance L apart. At t = 0 in the stationary
> frame, C is adjacent to A, but D hasn't made it to D yet.
> C is at x = 0 and the time on C's clock reads tC' = 0.
> At t = vL/c², B initiates a message and passes it to D at tD' = 0, and D
> sends it by tachyons to C: t = vL/c²:
> ___ C --> v _________ u' <---- D --> v A ________________________ B

exactly, *big_bang_zero* slow_now.

On Friday, April 30, 2021 at 1:36:50 AM UTC-6, Rob Acraman wrote:
>
> On Friday, April 30, 2021 at 12:38:39 AM UTC+10, hit...@yahoo.com wrote:
> >
> > On Thursday, April 29, 2021 at 7:20:35 AM UTC-6, Rob Acraman wrote:
> > >
> > > Not if you're careful.
> >
> > My point is that you and just about everyone else wasn't careful when dealing with tachyon
> > analysis.
>
> And my point is it's the other way round ;) You have not been careful enough, resulting in you
> not realising that when you switch frames, you have also been switching realities.

But I'm not the one switching frames. Please note that I did the entire analysis from the
perspective of Alice and Bob. According to them, Carol is at x = v²L/c², not at x = 0.
Therefore, tC' = γ(vL/c² - v^3L/c^4) = vL/c²/γ, not tC' = 0.

It's you and everyone else that's been switching frames and claiming that Dave can send
a signal at u' = -infinity to Carol at t' = 0 and then switching back and claiming that tachyons
send Alice and Bob back in time to t = 0, and therefore tachyons can't exist.

> Let's say that the trailing end of the pole has a light, that makes a SINGLE brief flash (maybe
> when it receives a tachyon message ;) ). We could even add somebody standing on the
> ground (so in the Barn frame) by the side of the light as it flashes - let's call that person L.
>
> That flash MUST be EITHER :
> Reality 1: BEFORE it enters the barn, besides Lenny
> OR
> Reality 2: AT/AFTER it entered the barn, besides Linda
>
> Under standard SR, ALL frames will always agree on the single reality. BOTH
> Barn-Frame and Pole-Frame agree on Reality-1, or BOTH Barn-Frame and Pole-Frame
> agree on Reality-2. This is being careful, and is what allows "jumping frames".

But it's most careful to analyze the complete problem from the pole-frame and then
analyze the complete problem from the barn-frame. Those should certainly agree,
right? If those disagree, there's something wrong. If they agree with each other, but
disagree with an analysis with frame-swiching, then something was done incorrectly
in the frame-switching analysis. Don't you agree?

> If someone is NOT careful, they may end up with thinking that that light flashes (eg,
> receives a tachyon message) in Reality-1 for the Pole frame, but Reality-2 for the
> Barn frame - which of course would be a "big no-no", a contradiction.

I agree. And that's EXACTLY what happens in conventional tachyon analyses.

> With such a result, that someone may choose to impose arbitrary rules forbidding
> "jumping frames" - you either look at the Barn frame with Lenny, or the Pole frame
> with Linda. In fact, that someone may confuse things even more, and give that person
> L the SAME name in both realities - for example, using "Lenny" for both cases. That
> someone would then insist on discussing the Barn Frame with Lenny, THEN the Pole
> frame with "Lenny". After all this work, that someone could then mistakenly think that
> it is the one who wants to "jump frames" that has not been careful, whereas in fact it's
> the other way round.
>
> The problem - the lack of care - is NOT with the person who wants to jump frames, but
> with the someone who wants to insist that Reality-1 and Reality-2 are the same reality.

I fail to understand how stating in one frame to do the analysis can possibly result in
mistakes. If one frame is really a different reality from frame two, then analyses from
each frame will give different results.

But we have to define what we mean be "different results." Obviously, we don't mean
that both will see the same lengths, or the same delta-t, right?

> > > Of course, can't do that "jumping frames" if you're using the two different frames
> > > to actually describe two different (so contradictory) realities.
> > >
> > > Funny that you can't do that "jumping frames" only with your tachyon model, but
> > > fine otherwise ;)
> >
> > Perhaps you didn't notice that I completed the analysis from the perspective of Alice
> > and Bob, and then I did the analysis from the perspective of Carol and Dave:
>
> Yes, you did Reality-1 from frame S, then Reality-2 from S'.

If that truly IS Reality-1 and Reality-2, then you prove my point: And doing
the complete analysis from both perspectives is the way you can know if
you have one or two realities. The scenario below cannot create a message
loop. A and C aren't adjacent when C receives the signal from D, or that
message is completed but hurls A and B back in time.

> > t = 0:
> > C --> v _______________ D --> v
> > A ________________________ B
> >
> > A and B are stationary a distance L apart. At t = 0 in the stationary frame,
> > C is adjacent to A, but D hasn't made it to D yet.
> >
> > C is at x = 0 and the time on C's clock reads tC' = 0.
> >
> > At t = vL/c², B initiates a message and passes it to D at tD' = 0, and D sends
> > it by tachyons to C:
> >
> > t = vL/c²:
> > ___ C --> v _________ u' <---- D --> v
> > A ________________________ B
> >
> > So can D send the signal to C at u' = infinity? After all, if we jump to the
> > moving frame:
> >
> > t' = 0:
> > ____ C ___________________ D
> > v <-- A _______________ <--v B
>
> Let's make the point here - according to standard non-FTL-non-Tachyon SR,
> this is EXACTLY the reality in the S' frame. There is NO contradiction, nor is
> there any "interference" from the AB frame. BOTH the S' and the S frames
> are equally, perfectly valid. Neither has ANY claim to being the "true" reality,
> or in mandating what is "The Dead Past".

No, it mandates a LIVE past for A and B :-)

> Even if one of the frames was stationary wrt a lab.

Or along a track.

> > You DO make a point, though. From S (the "stationary" frame), it looks to
> > Alice and Bob that Dave must send the signal to Carol at x = v²L/c², not to
> > Carol at x = 0, which isn't in the snapshot. But when you jump frames to
> > S', it looks to Dave that he CAN and MUST send the signal infinitely-fast
> >
> > Do you see a disconnect there? I sure do! That means to me that the scenario
> > cannot be a valid representation of reality.
>
> On that we agree ! Ooops, am I bisecting your comment ? Whoopsie ;)
>
> First, because Alice and Bob claim
>
> > the message loop cannot be completed while Carol and Dave think it can.
>
> To be clear, that is only a contradiction for an FTL (such as a Tachyon) model.
> Under standard non-FTL-non-tachyon SR, there is no problem : A,B,C and D
> all agree that the message loop cannot be completed.

And S claims it can't be completed for tachyons, also.

> > Second, if Dave sends the signal at u' = infinity, time goes backward in S.
> > That violates causality, entropy and the arrow of time. This is what happens
> > when jumping frames ... um ... "illegally."
>
> Yes, which is why I say that Dave cannot send the signal at u' = infinity.

So we're both in agreement on that. But if we set up the scenario differently.
So B passes the message to D at t =0, tD' = - γvL/c², D sends it to C at t = tC' =0

t = 0, B passes the message to D, who sends the signal to C:
____ C --> v ______________ u' <-- D --> v
____ A ________________________ B

Still from the perspective of A and B, u = -infinity but u' = -c²/v, so A and B
aren't hurled back in time.

> > When we do a COMPLETE analysis in one frame and THEN do a complete
> > analysis in the other frame, we see the inconsistency, but when we do half
> > in one frame and half in the other, we sail obliviously through to an invalid
> > conclusion.
>
> To take my Pole-Barn scenario earlier, if we do a COMPLETE analysis of Reality-1
> in the Barn frame, THEN a complete analysis of Reality-2 in the Pole frame, we
> see the inconsistency.

I don't see how that's possible. They MUST agree.

> If we do half in one and half in the other, we can sail through to the conclusion that
> those are two different realities.

That can only happen if complete analysis in each frame agree.

> > > > > That is a problem with FTL, not with taking the time-slice of the coordinates.
> > > >
> > > > You say "FTL" without defining what you mean by that. You seem to mean a
> > > > frame that's traveling FTL. Is that right? If so, that's not at all what I wrote.
> > >
> > > I meant whatever you meant when you referred to "has been done since FTL" :)
> >
> > My take is that tachyons don't reside in a "frame," meaning that observers can't
> > go there, and there's a good reason for that. It's been hypothesized that charged
> > tachyons would emit Cerenkov radiation, so tachyons must be UNCHARGED
> > particles. It's hard to imagine how one could construct observers without
> > protons and electrons :-)
>
> Photons don't reside in a "frame" either.

On Friday, April 30, 2021 at 2:48:04 PM UTC-7, hit...@yahoo.com wrote:

> But I find it less important to answer the belittlers as my confidence grows :-)
You mean, as your severe delusions grow. l

On Friday, April 30, 2021 at 12:36:50 AM UTC-7, Rob Acraman wrote:
>
> And likewise :) I am on this forum to both learn and share, and have never had the taste (nor understanding why) all the insult-throwing that goes on.

Your experience with Gary is very short, the day will come when you will get fed up with his lying, weaseling, distorting the facts and....you'll call him for what he is: a hardened crank.

On Friday, April 30, 2021 at 8:37:47 PM UTC-6, Dono. lied:
>
> On Friday, April 30, 2021 at 12:36:50 AM UTC-7, Rob Acraman wrote:
> >
> > And likewise :) I am on this forum to both learn and share, and have
> never had the taste (nor understanding why) all the insult-throwing that goes on.
>
> Your experience with Gary is very short, the day will come when you will get fed
> up with his lying, weaseling, distorting the facts and....you'll call him for what he
> is: a hardened crank.

See Rob? The belittler-in-chief.

To DOn'tkNOw:

“You are mean because inside you’re tiny. So tiny you cannot hold up the weight of
your own body. You must inflate your ego just to fill the skin. You float around like a
helium balloon. Blown up and bloated and gassy and empty.” ― Rivers Solomon

I've come across decomposed bodies that are less offensive than you are. --- Anon.

As an outsider, what do you think of the human race? --- Anon.

On Saturday, May 1, 2021 at 7:48:04 AM UTC+10, hit...@yahoo.com wrote:
> On Friday, April 30, 2021 at 1:36:50 AM UTC-6, Rob Acraman wrote:
> >
> > On Friday, April 30, 2021 at 12:38:39 AM UTC+10, hit...@yahoo.com wrote:
> > >
> > > On Thursday, April 29, 2021 at 7:20:35 AM UTC-6, Rob Acraman wrote:
> > > >
> > > > Not if you're careful.
> > >
> > > My point is that you and just about everyone else wasn't careful when dealing with tachyon
> > > analysis.
> >
> > And my point is it's the other way round ;) You have not been careful enough, resulting in you
> > not realising that when you switch frames, you have also been switching realities.
> But I'm not the one switching frames. Please note that I did the entire analysis from the
> perspective of Alice and Bob. According to them, Carol is at x = v²L/c², not at x = 0.
> Therefore, tC' = γ(vL/c² - v^3L/c^4) = vL/c²/γ, not tC' = 0.
>
> It's you and everyone else that's been switching frames and claiming that Dave can send
> a signal at u' = -infinity to Carol at t' = 0 and then switching back and claiming that tachyons
> send Alice and Bob back in time to t = 0, and therefore tachyons can't exist.

At core is the principle that no frame is "special". Anything and EVERYTHING that goes for one frame, goes equally for EVERY frame. NO frame can lay ownership to "reality".

Except you reject that. You allow infinite-speed tachyons - but ONLY in Alice/Bob's "Lab" frame S; Not in the Dave/Carol's frame S' (so tough luck, I guess, if they had a lab as well ;) )

Those infinite-speed tachyons emitted from Alice at (x=0, t=0) arrive at Bob at (x=L, t=0). That's a NEGATIVE t' in the C/D frame. You've sent Carol and Dave "back in time" - but that's OK because that's not the Lab frame. But infinite-speed tachyons in the C/D frame doing the same to the A/B "Lab" frame, no way.

I reject the Lab frame being special.

> > Let's say that the trailing end of the pole has a light, that makes a SINGLE brief flash (maybe
> > when it receives a tachyon message ;) ). We could even add somebody standing on the
> > ground (so in the Barn frame) by the side of the light as it flashes - let's call that person L.
> >
> > That flash MUST be EITHER :
> > Reality 1: BEFORE it enters the barn, besides Lenny
> > OR
> > Reality 2: AT/AFTER it entered the barn, besides Linda
> >
> > Under standard SR, ALL frames will always agree on the single reality. BOTH
> > Barn-Frame and Pole-Frame agree on Reality-1, or BOTH Barn-Frame and Pole-Frame
> > agree on Reality-2. This is being careful, and is what allows "jumping frames".
> But it's most careful to analyze the complete problem from the pole-frame and then
> analyze the complete problem from the barn-frame. Those should certainly agree,
> right? If those disagree, there's something wrong. If they agree with each other, but
> disagree with an analysis with frame-swiching, then something was done incorrectly
> in the frame-switching analysis. Don't you agree?

If there is ANY disagreements about ANY frame-invariant factors with frame-switching, then they do not "agree with eachother" but disagree by definition.

Those frame-invariant factors would be such as the location of the light when it flashed, or what time is showing on Bob's clock at a specific event at his location, or what speed someone (myself, or Dave) measure something travelling away from them. If there is ANY disagreement on these sorts of things, then there are two realities.

Let's take that last one - "what speed someone (myself, or Dave) measure something travelling away from them" .

Imagine I am standing by a ball-throwing machine, and I turn the ball-speed dial to 10 metres/second, and have a ball thrown - so it is moving away from me at 10 metres/second. However, I am on a train passing you at 30 metres/second at the moment I throw the ball. That means the ball is travelling at 40 metres/second relative to you.

Now, you can subtract the speed of the train and work out that that ball is moving at 10 metres/second RELATIVE TO ME. We would agree that that is the SAME reality, even though you and I are in different frames.

So, that speed that I measure the ball RELATIVE TO ME is a frame-invariant quantity (all frame agree that I would measure it to be 10 metres/second RELATIVE TO ME, so by definition in my frame). If you construct a "reality" where you say that ball was travelling at 5 metres/second RELATIVE TO ME, then that is a different reality.

Likewise, Dave has a tachyon-emitting machine with a dial that he can set to whatever speed he wants those tachyons to be travelling RELATIVE TO HIM. For example, he can set that dial to emit at (near-)infinity, or he can set it to emit at a slower speed like c²/v.

That setting on the tachyon-speed dial is a frame-invariant reality. EVERYBODY in every frame can see it, and everybody in every frame will agree that that speed setting is what he will measure the speed of those tachyons to be RELATIVE TO HIM, just as I did with those balls.

> > > Second, if Dave sends the signal at u' = infinity, time goes backward in S.
> > > That violates causality, entropy and the arrow of time. This is what happens
> > > when jumping frames ... um ... "illegally."
> >
> > Yes, which is why I say that Dave cannot send the signal at u' = infinity.
> So we're both in agreement on that.

I also say Alice can't send a signal at u = infinity for exactly the same reason - are we both in agreement on that ?

> But if we set up the scenario differently.
> So B passes the message to D at t =0, tD' = - γvL/c², D sends it to C at t = tC' =0

In that case D is fully aware he has NOT sent the tachyon at (near-)infinite velocity RELATIVE TO HIM, so clearly a different reality from one where D would think he did - agreed ?

In other words, you are saying that Dave has CHOSEN to set the dial on his tachyon machine to emit at that slower speed of c²/v. This is NOT the reality where Dave has set his tachyon-speed dial to infinity.

>
> t = 0, B passes the message to D, who sends the signal to C:
> ____ C --> v ______________ u' <-- D --> v
> ____ A ________________________ B
>
> Still from the perspective of A and B, u = -infinity but u' = -c²/v, so A and B
> aren't hurled back in time.

So Alice gets the message at t=0, and then sends it to Bob who receives it at t=0.

So Alice must have set her tachyon machine to emit at (near-)infinity. You have given no explanation as to why she can set her tachyon-emission dial to that value (and Dave for some reason does-not / can-not), beyond just that Alice is in the "Lab" frame.

Likewise, you have no problem with the tachyons from A to B having Charles and Dave "hurled back in time".

> > So let's rephrase those earlier paragraphs with the Carol/Dave names, to see what you just
> > agreed to :
> >
> > Question: Dave and Carol are in the same frame S', distance L apart from eachother.
> As observed from S? What gives here?
> > At t=0, Dave sends Carol a tachyon signal travelling at 10c. What time will Carol receive that
> > signal.
> >
> > Your answer : If u = 10c, then ∆t = L/u, n'est-ce pas?
> That was for Alice and Bob, not for Carol and Dave.
> > Me : ALWAYS ?? Regardless of other frames ??????????
>
> > Your answer: Other frames have nothing to do with ∆t. How could they?
> So now your switching frame illegally?
....
> But you specified u, not u' in S'.

Again, I introduced "Alice" and "Bob" in this thread before you did - it was a stand-alone scenario, not connected to the A/B/C/D scenario you subsequently introduced. I made NO restriction on what frame they were in - they could be ANY one frame, and your answers stand.

You have just confirmed that for that one frame (which could be ANY frame), other frames have NOTHING to do with the ∆t within that frame (which, of course, is perfectly consistent with no frame interfering with any other - such as by being in any more "special" or "real" than any other).

Since I did not specify a frame, consequently my scenario applies equally to u in S as to u' in S'.

> > We have an experiment where you are sending a (near-)infinite-speed tachyon
> > message to me in the same frame. During that experiment, the laws of physics
> > don't "know" whether I am intending to pass on that message (so potentially
> > creating a message loop) or not.
> >
> > So can you send me that (near-)infinite-speed tachyon message, or can't you ? You
> > can or you can't - Yes or No ?
> Yes.

OK, so your and my clocks have been previously synchronised. Your clock reads 0 at the instant you send me those (near-)infinite-speed tachyons. What will my clock be reading when I receive those tachyons ?

There was a lot of stuff to cover in that previous post, so let's summarise..
I know you said "Start from Bob", but both of the have Alice at x=0,t=0, so let's start from there - a loop is a loop where ever it starts ! Naturally, let's also start where origins co-incide - so x=0,t=0 is coincident with x'=0,t'=0.

Firstly, the impossible message :
1.1 Alice (t=0,x=0) sets her Tachyon-Speed dial to u=infinity, and sends a tachyon at that speed RELATIVE TO HER to Bob
1.2 Bob receives that tachyon at (x=L, t=0), as he is coincident with Dave at (x'= γL, t'D = -γvL/c²)
1.3 Dave sets his Tachyon-Speed dial to u' = infinity, and fires the tachyon at that speed RELATIVE TO HIMSELF.
1.4 Since infinite-speed tachyons take zero time, this means all observers in the CD frame will receive it as their clocks read the same time as D's clock does when she sends it.
1.4 However, only one such CD-frame observer will be adjacent to Alice as their clock reads this value (t'C = -γvL/c².) Let's call this person Charles.
1.5 So Charles is co-located with Alice, but earlier than t'=0 - so ERROR: impossible back-in-time message.

So you blame this on "frame-swapping", and instead suggest that the following alternative views are of the same reality :

2.1 Alice (t=0,x=0) sets her Tachyon-Speed dial to u=c²/v, and sends a tachyon at that speed RELATIVE TO HER to Bob
2.2 After some transit time, Bob receives that tachyon at (x=L, t=vL/c²), as he is coincident with Dave whose clock is reading t'D=0
2.3 Dave sets his Tachyon-Speed dial to u' = infinity, and fires the tachyon at that speed RELATIVE TO HIMSELF.
2.4 Since infinite-speed tachyons take zero time, this means all observers in the CD frame will receive it as their clocks read the same time as D's clock does when she sends it.
2.4 However, only one such CD-frame observer will be adjacent to Alice as their clock reads this value (t'C = 0.) This is the same Charles as in 1.4 and 1.5.
2.5 So Alice receives the message from Charles at t=0 - so crisis averted.

And also :

3.1 Alice (t=0,x=0) sets her Tachyon-Speed dial to u=infinity, and sends a tachyon at that speed RELATIVE TO HER to Bob
3.2 Since infinite-speed tachyons take zero time, this tachyon will be received by Bob with the same time on her clock that was showing on Alice's clock when she sent it. ie. Bob receives the tachyon at tB = 0. At this instant, he is co-located with Dave, whose clock is reading t'D = -γvL/c²
3.3 Dave sets his Tachyon-Speed dial to the slower u' = c²/v and fires the tachyon at that speed RELATIVE TO HIMSELF.
3.4 This means that unlike the u' = infinity tachyon, this tachyon will take some definite period of time to travel, eventually arriving at Alice's location at t' = 0.
3.4 This in turn means that it will be a DIFFERENT passenger (not Charles) on the C/D "train" who will be adjacent to Alice when the tachyon arrives.. Let's call this person Calvin.
3.5 So Alice receives the message from Calvin at t=0 - so crisis averted..

Firstly, you appear to think that descriptions 2 and 3 are somehow compatible views of the same reality. That is impossible for numerous reasons , such as described in my ball-throwing machine on the train, and because Alice MUST receive the message from ONE individual - Charles or Calvin. Sweeping it under the rug by just calling them both "Carol" doesn't work.

Secondly, the BIG issue with descriptions 2 and 3 is that there is nothing COMPELLING the individuals to turn their tachyon-speed dials to c²/v rather than infinity. It's just something that they have to do in order to avoid the impossible-message.

Further, of course, that c²/v factor is dependent on those specific frames. For example, let's say c²/v worked out to be 10c for this specific pair of frames. Even if something prevents them turning their tachyon-speed dials to infinity, that 10c limitation that they CAN use could still be used if there was another frame (Eve and Frank's) passing by at the same time.

On Monday, May 3, 2021 at 12:42:14 AM UTC-6, Rob Acraman wrote:
>
> On Saturday, May 1, 2021 at 7:48:04 AM UTC+10, hit...@yahoo.com wrote:
> >
> > On Friday, April 30, 2021 at 1:36:50 AM UTC-6, Rob Acraman wrote:
> > >
> > > And my point is it's the other way round ;) You have not been careful enough, resulting in you
> > > not realising that when you switch frames, you have also been switching realities.
> >
> > But I'm not the one switching frames. Please note that I did the entire analysis from the
> > perspective of Alice and Bob. According to them, Carol is at x = v²L/c², not at x = 0.
> > Therefore, tC' = γ(vL/c² - v^3L/c^4) = vL/c²/γ, not tC' = 0.
> >
> > It's you and everyone else that's been switching frames and claiming that Dave can send
> > a signal at u' = -infinity to Carol at t' = 0 and then switching back and claiming that tachyons
> > send Alice and Bob back in time to t = 0, and therefore tachyons can't exist.
>
> At core is the principle that no frame is "special". Anything and EVERYTHING that goes for
> one frame, goes equally for EVERY frame. NO frame can lay ownership to "reality".
>
> Except you reject that. You allow infinite-speed tachyons - but ONLY in Alice/Bob's "Lab" frame S;
> Not in the Dave/Carol's frame S' (so tough luck, I guess, if they had a lab as well ;) )

You're missing my point. The fact that analysis (completely) from S and analysis (co,pletely) from
S' don't agree tells us that we cannot create a valid loop with that particular arrangement. Doing
half the analysis and then jumping frames for the other half obscured that fact and led to an
invalid conclusion.

> Those infinite-speed tachyons emitted from Alice at (x=0, t=0) arrive at Bob at (x=L, t=0). That's a
> NEGATIVE t' in the C/D frame. You've sent Carol and Dave "back in time" - but that's OK because
> that's not the Lab frame. But infinite-speed tachyons in the C/D frame doing the same to the A/B
> "Lab" frame, no way.
>
> I reject the Lab frame being special.

So do I. It's okay to send u = ∞ tachyons to receivers at relative rest, but they can't be used to create
a message loop BECAUSE they result in two different realities. What we want to find is a scenario
that results in ONE reality.

> > > Let's say that the trailing end of the pole has a light, that makes a SINGLE brief flash (maybe
> > > when it receives a tachyon message ;) ). We could even add somebody standing on the
> > > ground (so in the Barn frame) by the side of the light as it flashes - let's call that person L.
> > >
> > > That flash MUST be EITHER :
> > > Reality 1: BEFORE it enters the barn, besides Lenny
> > > OR
> > > Reality 2: AT/AFTER it entered the barn, besides Linda
> > >
> > > Under standard SR, ALL frames will always agree on the single reality.. BOTH
> > > Barn-Frame and Pole-Frame agree on Reality-1, or BOTH Barn-Frame and Pole-Frame
> > > agree on Reality-2. This is being careful, and is what allows "jumping frames".
> >
> > But it's most careful to analyze the complete problem from the pole-frame and then
> > analyze the complete problem from the barn-frame. Those should certainly agree,
> > right? If those disagree, there's something wrong. If they agree with each other, but
> > disagree with an analysis with frame-swiching, then something was done incorrectly
> > in the frame-switching analysis. Don't you agree?
>
> If there is ANY disagreements about ANY frame-invariant factors with frame-switching,
> then they do not "agree with eachother" but disagree by definition.
>
> Those frame-invariant factors would be such as the location of the light when it flashed,
> or what time is showing on Bob's clock at a specific event at his location, or what speed
> someone (myself, or Dave) measure something travelling away from them. If there is ANY
> disagreement on these sorts of things, then there are two realities.
>
> Let's take that last one - "what speed someone (myself, or Dave) measure something
> travelling away from them" .
>
> Imagine I am standing by a ball-throwing machine, and I turn the ball-speed dial to 10 metres
> /second, and have a ball thrown - so it is moving away from me at 10 metres/second.
> However, I am on a train passing you at 30 metres/second at the moment I throw the ball.
> That means the ball is travelling at 40 metres/second relative to you.
>
> Now, you can subtract the speed of the train and work out that that ball is moving at 10 metres
>/second RELATIVE TO ME. We would agree that that is the SAME reality, even though you and I
> are in different frames.
>
> So, that speed that I measure the ball RELATIVE TO ME is a frame-invariant quantity (all frame
> agree that I would measure it to be 10 metres/second RELATIVE TO ME, so by definition in my
> frame). If you construct a "reality" where you say that ball was travelling at 5 metres/second
> RELATIVE TO ME, then that is a different reality.
>
> Likewise, Dave has a tachyon-emitting machine with a dial that he can set to whatever speed
> he wants those tachyons to be travelling RELATIVE TO HIM. For example, he can set that dial
> to emit at (near-)infinity, or he can set it to emit at a slower speed like c²/v.
>
> That setting on the tachyon-speed dial is a frame-invariant reality. EVERYBODY in every frame
> can see it, and everybody in every frame will agree that that speed setting is what he will
> measure the speed of those tachyons to be RELATIVE TO HIM, just as I did with those balls.

Well, only half of "everybody in every frame" can detect tachyons :-)

> > > > Second, if Dave sends the signal at u' = infinity, time goes backward in S.
> > > > That violates causality, entropy and the arrow of time. This is what happens
> > > > when jumping frames ... um ... "illegally."
> > >
> > > Yes, which is why I say that Dave cannot send the signal at u' = infinity.
> >
> > So we're both in agreement on that.
>
> I also say Alice can't send a signal at u = infinity for exactly the same reason
> - are we both in agreement on that ?

Yep, as an active participant in a message loop.

> > But if we set up the scenario differently.
> > So B passes the message to D at t =0, tD' = - γvL/c², D sends it to C at t = tC' =0
>
> In that case D is fully aware he has NOT sent the tachyon at (near-)infinite velocity
> RELATIVE TO HIM, so clearly a different reality from one where D would think he did -
> agreed ?

Sure, a message loop cannot be created by violating causality. If the analysis says
causality IS violated, we must disbelieve the analysis.

> In other words, you are saying that Dave has CHOSEN to set the dial on his tachyon
> machine to emit at that slower speed of c²/v. This is NOT the reality where Dave has
> set his tachyon-speed dial to infinity.

Yep, the scenario is busted.

> > t = 0, B passes the message to D, who sends the signal to C:
> > ____ C --> v ______________ u' <-- D --> v
> > ____ A ________________________ B
> >
> > Still from the perspective of A and B, u = -infinity but u' = -c²/v, so A and B
> > aren't hurled back in time.
>
> So Alice gets the message at t=0, and then sends it to Bob who receives it at t=0.
>
> So Alice must have set her tachyon machine to emit at (near-)infinity. You have
> given no explanation as to why she can set her tachyon-emission dial to that value
> (and Dave for some reason does-not / can-not), beyond just that Alice is in the "Lab" frame.
>
> Likewise, you have no problem with the tachyons from A to B having Charles and Dave
> "hurled back in time".

So A sends it at w = c²/v and B isn't adjacent to D anymore; and the signal gets back to
B at t = vL/c².

Is it important that A send the signal to B at w = c²/v? Not sure, but suppose C sent it DIRECTLY
to B: C is moving toward B, so C can send it at w' = ∞ and B will receive it at w = c²/v. Why
would passing it to A and letting him send it change anything?

> > > So let's rephrase those earlier paragraphs with the Carol/Dave names, to see what you just
> > > agreed to :
> > >
> > > Question: Dave and Carol are in the same frame S', distance L apart from eachother.
>
> > As observed from S? What gives here?
> >
> > > At t=0, Dave sends Carol a tachyon signal travelling at 10c. What time will Carol receive that
> > > signal.
> > >
> > > Your answer : If u = 10c, then ∆t = L/u, n'est-ce pas?
> >
> > That was for Alice and Bob, not for Carol and Dave.
> >
> > > Me : ALWAYS ?? Regardless of other frames ??????????
> >
> > > Your answer: Other frames have nothing to do with ∆t. How could they?
> >
> > So now your switching frame illegally?
> ...
> > But you specified u, not u' in S'.
>
> Again, I introduced "Alice" and "Bob" in this thread before you did - it was a
> stand-alone scenario, not connected to the A/B/C/D scenario you subsequently
> introduced. I made NO restriction on what frame they were in - they could be ANY
> one frame, and your answers stand.

On Monday, May 3, 2021 at 3:57:35 AM UTC-6, Rob Acraman wrote:
>
> There was a lot of stuff to cover in that previous post, so let's summarise.
> I know you said "Start from Bob", but both of the have Alice at x=0,t=0, so let's start from
> there - a loop is a loop where ever it starts ! Naturally, let's also start where origins co-incide -
> so x=0,t=0 is coincident with x'=0,t'=0.
>
> Firstly, the impossible message :
> 1.1 Alice (t=0,x=0) sets her Tachyon-Speed dial to u=infinity, and sends a tachyon at that
> speed RELATIVE TO HER to Bob
> 1.2 Bob receives that tachyon at (x=L, t=0), as he is coincident with Dave at
> (x'= γL, t'D = -γvL/c²)
> 1.3 Dave sets his Tachyon-Speed dial to u' = infinity, and fires the tachyon at that speed
> RELATIVE TO HIMSELF.

Yes, u', but u' = -∞.

> 1.4 Since infinite-speed tachyons take zero time, this means all observers in the CD
> frame will receive it as their clocks read the same time as D's clock does when she sends
> it.
> 1.4 However, only one such CD-frame observer will be adjacent to Alice as their clock
> reads this value (t'C = -γvL/c².) Let's call this person Charles.

Can't happen. At t = 0 there is ONLY one position where t' = -γvL/c², and thats at x = L.

> 1.5 So Charles is co-located with Alice, but earlier than t'=0 - so ERROR: impossible
> back-in-time message.
>
> So you blame this on "frame-swapping",

Yes, because t = 0 in the S frame and tC' = 0 but tD' = -γvL/c². If you deny that, you deny
relativity of simultaneity.

> and instead suggest that the following alternative views are of the same reality :
>
> 2.1 Alice (t=0,x=0) sets her Tachyon-Speed dial to u=c²/v, and sends a tachyon at that
> speed RELATIVE TO HER to Bob
> 2.2 After some transit time, Bob receives that tachyon at (x=L, t=vL/c²), as he is
> coincident with Dave whose clock is reading t'D=0
> 2.3 Dave sets his Tachyon-Speed dial to u' = infinity, and fires the tachyon at that speed
> RELATIVE TO HIMSELF.

Actually, I say he sets it to u' = -c²/v because A and B say he must..

> 2.4 Since infinite-speed tachyons take zero time, this means all observers in the CD
> frame will receive it as their clocks read the same time as D's clock does when she
> sends it.
> 2.4 However, only one such CD-frame observer will be adjacent to Alice as their clock reads this value (t'C = 0.) This is the same Charles as in 1..4 and 1.5.
> 2.5 So Alice receives the message from Charles at t=0 - so crisis averted.

There is still the crisis that some frame was hurled back in time, so this isn't my scenario.
Neither is this:

> And also :
>
> 3.1 Alice (t=0,x=0) sets her Tachyon-Speed dial to u=infinity, and sends a tachyon at that
> speed RELATIVE TO HER to Bob
> 3.2 Since infinite-speed tachyons take zero time, this tachyon will be received by Bob with
> the same time on her clock that was showing on Alice's clock when she sent it. ie. Bob
> receives the tachyon at tB = 0. At this instant, he is co-located with Dave, whose clock is
> reading t'D = -γvL/c²
> 3.3 Dave sets his Tachyon-Speed dial to the slower u' = c²/v and fires the tachyon at that
> speed RELATIVE TO HIMSELF.
> 3.4 This means that unlike the u' = infinity tachyon, this tachyon will take some definite
> period of time to travel, eventually arriving at Alice's location at t' = 0.
> 3.4 This in turn means that it will be a DIFFERENT passenger (not Charles) on the C/D
> "train" who will be adjacent to Alice when the tachyon arrives. Let's call this person Calvin.
> 3.5 So Alice receives the message from Calvin at t=0 - so crisis averted.
>
> Firstly, you appear to think that descriptions 2 and 3 are somehow compatible views of the
> same reality.

No, I don't. I think two COMPLETE analyses, one done from S and the other from S' prove
that the scenario is fatally flawed.

> That is impossible for numerous reasons , such as described in my ball-throwing machine
> on the train, and because Alice MUST receive the message from ONE individual - Charles
> or Calvin. Sweeping it under the rug by just calling them both "Carol" doesn't work.

Only by jumping frames can you conclude that ANYONE can receive the message before it's
sent:

x' = γ(x - vt)
t' = γ(t - vx/c²)

How many observers in S' can be at x = 0, t = 0?
Only one: Carol. Where will Carol be at t = vL/c²?
How many observers in S' can be at x = 0, t = vL/c²?
t' = γ(vL/c² - 0), x' = γ(0 - v²L/c²)

Looks like one, but his, her, its clock will NOT read zero. It'll be t' = γvL/c²

> Secondly, the BIG issue with descriptions 2 and 3 is that there is nothing COMPELLING
> the individuals to turn their tachyon-speed dials to c²/v rather than infinity. It's just
> something that they have to do in order to avoid the impossible-message.

So not being able to complete a loop isn't "compelling"?

> Further, of course, that c²/v factor is dependent on those specific frames. For example,
> let's say c²/v worked out to be 10c for this specific pair of frames.. Even if something
> prevents them turning their tachyon-speed dials to infinity, that 10c limitation that they
> CAN use could still be used if there was another frame (Eve and Frank's) passing by at
> the same time.

Not if you do THOSE analyses completely from their respective frames. "v" is a parameter
of the problem. It determine the u in u = -c²/v. If you think that adding another pair of
observers in a frame S'' can actually ADD anything to the experiment, have a go at THREE
complete analyses. It might be interesting. I'll be happy to critique :-)

First however, you might look at Figure 7 in https://vixra.org/abs/2011.0076 to see what
my position REALLY is. Of course, B initiates the message in this scenario.. Some
logistics must be adjusted to accommodate A initiating the message.

Gary Harnagel wrote:

>> Except you reject that. You allow infinite-speed tachyons - but ONLY in
>> Alice/Bob's "Lab" frame S; Not in the Dave/Carol's frame S' (so tough
>> luck, I guess, if they had a lab as well )
>
> You're missing my point. The fact that analysis (completely) from S and
> analysis (co,pletely) from S' don't agree tells us that we cannot create
> a valid loop with that particular arrangement. Doing half the analysis
> and then jumping frames for the other half obscured that fact and led to
> an invalid conclusion.
>
>Yes, the E-Matrix composed of continuous E-Strings. The E-Strings
> transmit transverse waves

Send me a sample, for me to see that it does.

On Monday, May 3, 2021 at 9:20:16 AM UTC-5, hit...@yahoo.com wrote:

> You're missing my point. The fact that analysis (completely) from S and analysis (co,pletely) from
> S' don't agree tells us that we cannot create a valid loop with that particular arrangement. Doing
> half the analysis and then jumping frames for the other half obscured that fact and led to an
> invalid conclusion.

Please re-read my initial response to your lead post to this thread.

You repeatedly have referred to David Morin's recommendation "An extremely
important strategy in solving relativity problems is to plant yourself in a frame
and stay there." As I explained, Morin was giving advice to *beginner* students
of relativity solving the simple sort of *beginner* relativity problems that form
the bulk of those found in elementary textbooks on the subject. As I browse
through French's *introductory* textbook and Taylor & Wheeler's *introductory*
textbook, I do not immediately see any problems that *require* switching frames
in order to solve the problem. True, there are problems in both textbooks that
benefit from one looking at the problem from two different frames. One of my
favorite examples of such is problem 52 on pages 98-99 of the first edition of
T&W, "The meter-stick paradox":
https://www.eftaylor.com/pub/stp/STP1stEdExercP81to100.pdf
where the solution is found on pp 24-25 of the following:
https://www.eftaylor.com/pub/stp/STP1stEdExercSolns.pdf
I refer to Taylor and Wheeler in my (currently at least 95% my words, and
certainly 100% my illustration) discussion of Thomas rotation in Wikipedia:
https://en.wikipedia.org/wiki/Special_relativity#Thomas_rotation

The point is, introductory problems are almost always *single-step* problems,
where everything can be solved from a single frame, *provided* that one
has identified the proper frame from which to perform the analysis.

But please remember where I wrote, "Choice of frame can make all the
difference between a problem which is exasperatingly difficult to solve,
versus one which is almost trivial", and I gave as example of the analysis
of different variants of experiments measuring transverse Doppler effect:
https://en.wikipedia.org/wiki/Relativistic_Doppler_effect#Transverse_Doppler_effect
(Please note that all the illustrations in the above section are mine, while
at least 95% of the words are mine. On the other hand, I completely *disown*
the section on longitudinal Doppler effect which has been re-written by too
many people, resulting in a mixed-up hash.)

The analysis of FTL closed loops is *not* a single-step problem.

The "stationary" frame is the wrong frame from which to analyze
superluminal motions in the moving frame, and the moving frame is the
wrong frame from which to analyze motions in the stationary frame.
Because nobody has any experience in superluminal motions, most of
us would get ourselves, as I wrote, "all twisted up" trying to analyze this
multi-step problem from a single frame.

This includes you.

As Rob wrote, the *real* danger from a *beginner* student jumping frames, is
that the *beginner* student risks " 'writing down an equation that combines
quantities that are measured in different frames, which is a no-no.' So if you have a
an un-primed and a primed frame, his no-no is that you never write t'/L or t/L'.
NOTHING against the perfectly good and proper practice of being able to observe
for any frame, at any time t in that frame, the (x, y, z) coordinates in that frame at
that frame's time t of all objects."

Nota bene: It is a perfectly good and proper practice to switch frames so as to
observe, within that frame, the (x,y,z,t) coordinates of events within that frame.
One then relates events between the two frames using the LT.

Note how Morin analyzes the FTL closed loop. He first analyzes the scenario
without Minkowski diagrams:
https://drive.google.com/file/d/1Gv8SGdssOWqSuK70gLVSuWkJpa-Uy08i/view?usp=sharing

He follows up later with analysis using Minkowski diagrams:
https://drive.google.com/file/d/1Gv8SGdssOWqSuK70gLVSuWkJpa-Uy08i/view?usp=sharing

In both versions of his FTL closed loop analysis, Morin makes *informed* jumps
between frames to handle different stages of this *multi-step* problem.

In this thread, Rob has covered most of the same points that I did when I debated
with you, only without all the pretty pictures and with a different emphasis:
https://drive.google.com/drive/folders/1G8VUcfkrLVd7Jxt9tV62Wod9pMferBZz?usp=sharing

For example, where Rob noted that you are switching realities in your analysis, I
provided this illustration:
https://drive.google.com/file/d/1mZJcqaV2KieXFNU5iWHCsVtDK21HOLWE/view?usp=sharing

Rob is doing a good job. You, on the other hand, have been blinded by your
philosophical prejudices and BEGINNER misunderstandings.