Any resolutions to FTL paradoxes?

[KelvinZero]

Kelvinzero, here is a response for a hard science fictional viewpoint. There is no way to have FTL drive without causing paradoxes in SR and GR. However, the complete answer is not so simple.

Hi RSE, we seem to have found a simple way to describe FTL without paradoxes. I summarised what we have so far in the OP. (It is possible this gimmick only works for special relativity. It assumes things are pretty flat.)

There is absolutely no evidence or suggestion given that such a loophole exists. I repeat, It is not about being true, just about being describable.

(I actually started this thread thinking we could not even find this, and that a paradox could be formed with a single FTL flight making frame of reference irrelevant. I thought we would have to introduce massive spacewalls or such that pretty much isolate regions of space visited by FTL. Turns out it is not that bad)

[kamill85]

Guys, I registered just to say this - this entire thread encapsulates one giant misunderstanding between the two parties.

It seems there are two things confused:
1. "FTL" - Faster Than Light travel in space, which YES, would cause paradoxes and allow messages being sent back in time (like shown on the diagrams and the PBS video).
2. Warp-drive, "Jump Drive", etc. are actually considered an Apparent FTL,
 wikipedia quote:

Apparent FTL is not excluded by general relativity, however, any Apparent FTL physical plausibility is speculative. Examples of Apparent FTL proposals are the Alcubierre drive and the traversable wormhole.

So yes, if you travel using FTL drive, in space, you will open door to a full range of paradoxes, incl. Temporal Viber messaging app if you like.

If you jump around different coordinates in space, via worm-hole or a warp-drive, these paradoxes do no apply. There is no acceleration work being done. You take a patch of space (your ship and then some space around it) from place X and basically "teleport" it to a place Y. Clock speed/rates are NOT affected. Time on board such ships goes at same rate as at the place it started from.

Now, having said that, there is something that is usually not considered when it comes to A-FTL (Apparent FTL):
If we take a patch of space with a reference frame of position X (Earth#1), warp through space to position Y (with Earth#2 for example), lets say 150k light years across our galaxy, then YES, we have moved 150k light years. However, the moment we turn off the drive we wouldn't see the Earth#2 (our original target) waiting for us in front of the ship for very long - it would instead instantly move away from us (since its in different reference frame / moving at different speed/direction etc.). So technically, A-FTL ships on top of "jumping around" would also have to use regular, relativistic drives to match the target reference frames.

Hopefully this cleared some things up. Thank you.

[meberbs]

If you jump around different coordinates in space, via worm-hole or a warp-drive, these paradoxes do no apply. There is no acceleration work being done. You take a patch of space (your ship and then some space around it) from place X and basically "teleport" it to a place Y. Clock speed/rates are NOT affected. Time on board such ships goes at same rate as at the place it started from.

As I have told this to WarpTech repeatedly, the time experienced by the people on board the ship is unrelated to the paradoxes. Unless the existence of the wormhole you used prevents the creation of a wormhole by another ship, it is trivial to implement the paradox.

So technically, A-FTL ships on top of "jumping around" would also have to use regular, relativistic drives to match the target reference frames.

This is not a significant problem, which is why people don't bother discussing it, and irrelevant to paradoxes.

[aceshigh]

Guys, I registered just to say this - this entire thread encapsulates one giant misunderstanding between the two parties.

no misundestanding

It seems there are two things confused:
1. "FTL" - Faster Than Light travel in space, which YES, would cause paradoxes and allow messages being sent back in time (like shown on the diagrams and the PBS video).
2. Warp-drive, "Jump Drive", etc. are actually considered an Apparent FTL,
 wikipedia quote:

Apparent FTL is not excluded by general relativity, however, any Apparent FTL physical plausibility is speculative. Examples of Apparent FTL proposals are the Alcubierre drive and the traversable wormhole.

the two things are not being confused, and we know them pretty well.

If you jump around different coordinates in space, via worm-hole or a warp-drive, these paradoxes do no apply. There is no acceleration work being done. You take a patch of space (your ship and then some space around it) from place X and basically "teleport" it to a place Y. Clock speed/rates are NOT affected. Time on board such ships goes at same rate as at the place it started from.

you are showing here that it's you who do not understand how things work.

your problem lies in thinking you are travelling through 3D space and time is another thing, separate.

Time and space are deeply connected. There is no universal time. So it doesn´t matter you take a bubble of space time with you, if you travelled faster than the speed of causality, you will still may be dropped in a moment of time BEFORE you departed the moment you turn it off.

Hopefully this cleared some things up. Thank you.

yes, it's clear you are not very aware of how light cones and causality works. I posted some videos pages ago. Watch them again and again.

[sghill]

Time and space are deeply connected. There is no universal time. So it doesn´t matter you take a bubble of space time with you, if you travelled faster than the speed of causality, you will still may be dropped in a moment of time BEFORE you departed the moment you turn it off.

I get this part, but I still ask "so what?"

A ship's sudden appearance in a moment in the past won't affect the moment it left the present until the speed of causality reaches it. So therefore, can't a paradox never be created because the effects of causality can't reach the origination point prior to the moment of departure? It seems to me that I can't affect the local time in the past and create a paradox unless I use a time machine that ignores distance. An FTL ship can't do it.

E.G., if in 2017 I warp out 100 light years in only 2 years of local time, I've gone back in time 100 years. But it still takes 100 years for me to transmit my radio message of "Oh crap, I just looked through a my ship's big telescope back at the Earth, and Shoeless Joe is cheating at baseball! Don't place your bets on Chicago" to get back to Earth 100 years later (in 2019). If I instead hop in my ship and warp back to Earth, now 4 years have passed locally, and no one on Earth cares about the Black Sox in 2021, but I've got some cool videos of what Earth looked like in the past that I recorded through my ship's telescope.

Hopefully this cleared some things up. Thank you.

yes, it's clear you are not very aware of how light cones and causality works. I posted some videos pages ago. Watch them again and again.

Please play nice. Polite questions and answers are the soul of NSF. If we wanted romper room, we'd take it to Reddit.

[meberbs]

E.G., if in 2017 I warp out 100 light years in only 2 years of local time, I've gone back in time 100 years. But it still takes 100 years for me to transmit my radio message of "Oh crap, I just looked through a my ship's big telescope back at the Earth, and Shoeless Joe is cheating at baseball! Don't place your bets on Chicago" to get back to Earth 100 years later (in 2019).

I don't think you have thought through your own description here. You are describing going into the past and then seeing light from the future.

Anyway, the real problem has been described multiple times in these threads. The short version is that you need to recognize that since there are frames where you travelled backwards in time, then travelling FTL the same way back the other direction means going even further back in time.

[KelvinZero]

So yes, if you travel using FTL drive, in space, you will open door to a full range of paradoxes, incl. Temporal Viber messaging app if you like.
If you jump around different coordinates in space, via worm-hole or a warp-drive, these paradoxes do no apply.

By cunning use of FTL, I responded to this before you posted:

The problem is that you can produce paradoxes just by sending messages. You can ignore what the postman experiences.

[KelvinZero]

It seems to me that I can't affect the local time in the past and create a paradox unless I use a time machine that ignores distance.

Hi sghill, this has been reiterated many times, here is another way of underlining the problem.

How do you define 'simultaneous' between two distant points?

Consider just that. What answer would you come up with?

Here is a very reasonable sounding approach:

* Place a beacon exactly halfway between these to points, A & B.
* The beacon emits a flash of light.
* You claim that the flash arrives at A at the exact same time as it arrives at B.
* Therefore, an instantaneous (ftl) message from A sent when it detects the beacon would be received by b when it detects that beacon.

If you buy that argument you trivially have a paradox, because someone in a different inertial frame will see the light pulse arriving at A and B at different times. They could use one instantaneous communication in their frame of reference to send a message to A, and another also in their frame of reference to get the information back from B before they sent it.

Suffice it to say that it turns out that our really reasonable way of defining simultaneous with a beacon between two points was nonsense.

So how would you define simultaneous?

[Johnnyhinbos]

Sorry, but the statements I see on this thread, like with the EM drive thread, crack me up. People post such strongly worded statements on the definite and immutable nature of the physical world around us. Because, you know, we know. Right?

Because, you know, we knew the world was a disk and the heavens above revolved about us.

Until it was proven wrong.

Then of course all was right in the world when Newtonian physics set it all straight. We finally had, literally, conservative physics. And any direction of thought that strayed from these new tenants was blasphemy and the spewers of such treason were dealt with accordingly. But hey, what now do we hear? A particle is a wave? A wave a particle? Where's a cat in a box when a tree falls... quantum leaps of faith?

So now - apparently now - we've got physics all trussed up, flipped over and hog tied. It's now our complete plaything because we've tamed it.

When will we learn - we know nothing in the big picture - hell, we can't even see what the big picture is. So stay in your reference frame and argue the world as you want it perceived, but just take a moment to reflect back into the past and see that we know absolutely nothing - but the future is just waiting to be discovered.

So open your minds and expand past your rest frame for once in your life - you might just learn something amazing...

[nice evening, post cocktail rant. It's just that I get so tired of the directed bickering and blind arguments done to protect egos. It would be nice to see constructive debate without hostility. I'm a writer and this forum definitely provides fodder for my brain - but sadly it's does so by sorting out the personality traits I wish to quell in my own writings...]

[dustinthewind]

Sorry, but the statements I see on this thread, like with the EM drive thread, crack me up. People post such strongly worded statements on the definite and immutable nature of the physical world around us. Because, you know, we know. Right?

Because, you know, we knew the world was a disk and the heavens above revolved about us.

Until it was proven wrong.

Then of course all was right in the world when Newtonian physics set it all straight. We finally had, literally, conservative physics. And any direction of thought that strayed from these new tenants was blasphemy and the spewers of such treason were dealt with accordingly. But hey, what now do we hear? A particle is a wave? A wave a particle? Where's a cat in a box when a tree falls... quantum leaps of faith?

So now - apparently now - we've got physics all trussed up, flipped over and hog tied. It's now our complete plaything because we've tamed it.

When will we learn - we know nothing in the big picture - hell, we can't even see what the big picture is. So stay in your reference frame and argue the world as you want it perceived, but just take a moment to reflect back into the past and see that we know absolutely nothing - but the future is just waiting to be discovered.

So open your minds and expand past your rest frame for once in your life - you might just learn something amazing...

[nice evening, post cocktail rant. It's just that I get so tired of the directed bickering and blind arguments done to protect egos. It would be nice to see constructive debate without hostility. I'm a writer and this forum definitely provides fodder for my brain - but sadly it's does so by sorting out the personality traits I wish to quell in my own writings...]

Feel free to make any specific suggestions that come to mind.  I have been wrong before and will openly consider what you have to say and do my best not to be demeaning.  I prefer the sparring back and forth of ideas as it stimulates the imagination and helps me gain over time a visual understanding of what hopefully represents the abstract hidden reality.  If two puzzle pieces don't fit together that should, then it is only an interesting clue of something yet to be uncovered.  It's not easy to find people to spar with.  That's probably what keeps me coming back to this forum. 

I speak for myself and others like me.  There are some that can come across as rude.

[kamill85]

If you jump around different coordinates in space, via worm-hole or a warp-drive, these paradoxes do no apply. There is no acceleration work being done. You take a patch of space (your ship and then some space around it) from place X and basically "teleport" it to a place Y. Clock speed/rates are NOT affected. Time on board such ships goes at same rate as at the place it started from.

As I have told this to WarpTech repeatedly, the time experienced by the people on board the ship is unrelated to the paradoxes. Unless the existence of the wormhole you used prevents the creation of a wormhole by another ship, it is trivial to implement the paradox.

So technically, A-FTL ships on top of "jumping around" would also have to use regular, relativistic drives to match the target reference frames.

This is not a significant problem, which is why people don't bother discussing it, and irrelevant to paradoxes.

Uh, yes it matters. As in the Twin Paradox, it matters who is the observer and who is changing from the observer time-reference by doing acceleration work. In the A-FTL case there is NO acceleration work being done. Their time remains in-sync regardless of the distance.

Adding a third object traveling at any speed (less than c) through space does not change anything nor opens door to any paradox.

[kamill85]

you are showing here that it's you who do not understand how things work.

your problem lies in thinking you are travelling through 3D space and time is another thing, separate.

Time and space are deeply connected. There is no universal time. So it doesn´t matter you take a bubble of space time with you, if you travelled faster than the speed of causality, you will still may be dropped in a moment of time BEFORE you departed the moment you turn it off.
...
yes, it's clear you are not very aware of how light cones and causality works. I posted some videos pages ago. Watch them again and again.

I guess you are the one that failed to understand the difference between relativistic travel through space and the warp drive "idea".

If you travel through space, from initial point X you must do some work to change your time-reference. Relative to some observer left behind at X your clock now ticks differently and you might appear shorter, fine. Yes, travel like that is locked to max of "speed of causality", beyond which things break down, hence no "FTL" through space might be possible, due to all paradoxes it might produce.

FTL "with space"  (the Apparent FTL) - for example a warp bubble that moves surrounding space around it-self, does NOT do any acceleration work. The clock ticks EXACTLY at same rate as at the starting point. There are no paradoxes coming out of it. No way to send messages to the past, nothing. A-FTL ship could be here 10:00, next moment jump 1 million ly away from us, spend 5 minutes there, jump back and it would be 10:05 here. This is how it would work (not saying that it will, just how the idea behind it works). Third observer traveling at any speed (less than c, say 0.7c), witnessing that coffee break 1 million ly away, wouldnt be able to send any message back in time to us, as anything he would have sent would arrive at best 1 million years later or if he chose to deliver it in person, about 1.42 million years later (not accounting for the space expansion).

If you fail to see the difference then I have some bad news for you.  PS. Next time try to be kinder in your comments.

[gospacex]

FTL "with space"  (the Apparent FTL) - for example a warp bubble that moves surrounding space around it-self, does NOT do any acceleration work. The clock ticks EXACTLY at same rate as at the starting point. There are no paradoxes coming out of it. No way to send messages to the past, nothing. A-FTL ship could be here 10:00, next moment jump 1 million ly away from us, spend 5 minutes there, jump back and it would be 10:05 here. This is how it would work (not saying that it will, just how the idea behind it works). Third observer traveling at any speed (less than c, say 0.7c), witnessing that coffee break 1 million ly away, wouldnt be able to send any message back in time to us, as anything he would have sent would arrive at best 1 million years later

The last statement is obviously wrong, since you already presumed that "bubble FTL" is possible. Therefore third observer's message, if sent using "bubble FTL" craft, CAN arrive sooner than 1 million years later.

[sghill]

It seems to me that I can't affect the local time in the past and create a paradox unless I use a time machine that ignores distance.

Hi sghill, this has been reiterated many times, here is another way of underlining the problem.

How do you define 'simultaneous' between two distant points?

Consider just that. What answer would you come up with?

Here is a very reasonable sounding approach:

* Place a beacon exactly halfway between these to points, A & B.
* The beacon emits a flash of light.
* You claim that the flash arrives at A at the exact same time as it arrives at B.
* Therefore, an instantaneous (ftl) message from A sent when it detects the beacon would be received by b when it detects that beacon.

If you buy that argument you trivially have a paradox, because someone in a different inertial frame will see the light pulse arriving at A and B at different times. They could use one instantaneous communication in their frame of reference to send a message to A, and another also in their frame of reference to get the information back from B before they sent it.

Suffice it to say that it turns out that our really reasonable way of defining simultaneous with a beacon between two points was nonsense.

So how would you define simultaneous?

I wouldn't. "Simultaneous" as a concept between participants doesn't exist except on paper. You can't measure simultaneous between participants because you can't transfer information between the two points simultaneously to actually prove that something occurred at exactly the same moment (that's totally different than proving an event happened simultaneously to a third party observer). Time must pass in order to transfer information between two points separated by distance.  I didn't describe FTL communications, I described FTL travel.

E.G., if in 2017 I warp out 100 light years in only 2 years of local time, I've gone back in time 100 years. But it still takes 100 years for me to transmit my radio message of "Oh crap, I just looked through a my ship's big telescope back at the Earth, and Shoeless Joe is cheating at baseball! Don't place your bets on Chicago" to get back to Earth 100 years later (in 2019).

I don't think you have thought through your own description here. You are describing going into the past and then seeing light from the future.

I'm describing going into the observer's future and seeing light from the target's past.  THe FTL ship is the observer. Earth is the target. If I warp out a distance, I see Earth's past, but I can't communicate what I see about Earth's past to Earth in the past, I can only communicate what I see of Earth's past to Earth in the present. thus no paradox for FTL ships.

Yes, FTL communications would communicate into the past, but that's not what I'm describing. I'm talking about a ship where the clocks continue forward for the occupants and Earth in the present. When the ship returns from some distance time has passed for both Earth in the present and also the ship. Information transfer to Earth in the past is not possible by the occupants on the ship, they can only observe.

[meberbs]

I didn't describe FTL communications, I described FTL travel.

FTL travel trivially allows FTL communication. This is not a meaningful distinction.

I'm describing going into the observer's future and seeing light from the target's past.  THe FTL ship is the observer. Earth is the target. If I warp out a distance, I see Earth's past, but I can't communicate what I see about Earth's past to Earth in the past, I can only communicate what I see of Earth's past to Earth in the present. thus no paradox for FTL ships.

None of what you are describing has any relation to the paradoxes. Go read the first 2 pages of the thread, at least through the worked examples.

[kamill85]

FTL "with space"  (the Apparent FTL) - for example a warp bubble that moves surrounding space around it-self, does NOT do any acceleration work. The clock ticks EXACTLY at same rate as at the starting point. There are no paradoxes coming out of it. No way to send messages to the past, nothing. A-FTL ship could be here 10:00, next moment jump 1 million ly away from us, spend 5 minutes there, jump back and it would be 10:05 here. This is how it would work (not saying that it will, just how the idea behind it works). Third observer traveling at any speed (less than c, say 0.7c), witnessing that coffee break 1 million ly away, wouldnt be able to send any message back in time to us, as anything he would have sent would arrive at best 1 million years later

The last statement is obviously wrong, since you already presumed that "bubble FTL" is possible. Therefore third observer's message, if sent using "bubble FTL" craft, CAN arrive sooner than 1 million years later.

If you read again, carefully this time, you would notice I said that ship can't do it, not that it's not possible. Said ship is traveling at 0.7C while passing by the coffee break event. Said ship can only keep flying at 0.7C in our direction or send some message at speed=C at best. So a message can arrive, again, at best in 1 million years after the coffee break took place, or 1.42million years later if delivered in person by the crew of said observer ship (ignoring space expansion).

That being said, why are you arguing over such tiny details? Do you like arguing for no reason? Trying to nitpick something someone said to point out possible statement error doesn't look good.

[meberbs]

If you jump around different coordinates in space, via worm-hole or a warp-drive, these paradoxes do no apply. There is no acceleration work being done. You take a patch of space (your ship and then some space around it) from place X and basically "teleport" it to a place Y. Clock speed/rates are NOT affected. Time on board such ships goes at same rate as at the place it started from.

As I have told this to WarpTech repeatedly, the time experienced by the people on board the ship is unrelated to the paradoxes. Unless the existence of the wormhole you used prevents the creation of a wormhole by another ship, it is trivial to implement the paradox.
...

Uh, yes it matters. As in the Twin Paradox, it matters who is the observer and who is changing from the observer time-reference by doing acceleration work. In the A-FTL case there is NO acceleration work being done. Their time remains in-sync regardless of the distance.

Adding a third object traveling at any speed (less than c) through space does not change anything nor opens door to any paradox.

Go read the descriptions of the paradox inducing situations early in this thread. The amount of time experienced by the people travelling does not matter. Keep rereading the descriptions until you get that, because if you still think otherwise you have not understood them. If you build a wormhole/warp bubble that takes you 100 light years away in 1 year (so that when you arrive you see light from 99 years before you left) but gravitational time dilation as you pass through makes you age 1000 years, this does not change the paradox. The additional object travelling at a different speed using its FTL can leave after you arrive, and arrive before you left.

FTL "with space"  (the Apparent FTL) - for example a warp bubble that moves surrounding space around it-self, does NOT do any acceleration work. The clock ticks EXACTLY at same rate as at the starting point. There are no paradoxes coming out of it. No way to send messages to the past, nothing. A-FTL ship could be here 10:00, next moment jump 1 million ly away from us, spend 5 minutes there, jump back and it would be 10:05 here. This is how it would work (not saying that it will, just how the idea behind it works). Third observer traveling at any speed (less than c, say 0.7c), witnessing that coffee break 1 million ly away, wouldnt be able to send any message back in time to us, as anything he would have sent would arrive at best 1 million years later

The last statement is obviously wrong, since you already presumed that "bubble FTL" is possible. Therefore third observer's message, if sent using "bubble FTL" craft, CAN arrive sooner than 1 million years later.

If you read again, carefully this time, you would notice I said that ship can't do it, not that it's not possible. Said ship is traveling at 0.7C while passing by the coffee break event. Said ship can only keep flying at 0.7C in our direction or send some message at speed=C at best. So a message can arrive, again, at best in 1 million years after the coffee break took place, or 1.42million years later if delivered in person by the crew of said observer ship (ignoring space expansion).

That being said, why are you arguing over such tiny details? Do you like arguing for no reason? Trying to nitpick something someone said to point out possible statement error doesn't look good.

He is not nitpicking a tiny detail, and you did not seem to even understand what he said.

The other ship also would have FTL capability.

"Said ship can only keep flying at 0.7C in our direction or send some message at speed=C at best"
This sentence ignores the 3rd option that the other ship uses its own FTL. Using its own FTL will result in it travelling to the distant past on Earth because it has a different definition of simultaneous.

[kamill85]

I didn't describe FTL communications, I described FTL travel.

FTL travel trivially allows FTL communication. This is not a meaningful distinction.

I'm describing going into the observer's future and seeing light from the target's past.  THe FTL ship is the observer. Earth is the target. If I warp out a distance, I see Earth's past, but I can't communicate what I see about Earth's past to Earth in the past, I can only communicate what I see of Earth's past to Earth in the present. thus no paradox for FTL ships.

None of what you are describing has any relation to the paradoxes. Go read the first 2 pages of the thread, at least through the worked examples.

Why FTL is even discussed at this point, of course any FTL transmission would travel back in time, math supports it, diagrams support it, experiments, well, do not support it as we are not sure how to make one. No need any third observer to prove/discover paradoxes. I'm talking about FTL through space of course.

Side note: Speaking of FTL experimentation, wave-function collapse problem, quantum effects etc., perhaps there is a way to construct an experiment that encapsulates some time-loop event but we only learn its outcome afterwards? (where causality is not broken/threatened). Some setup that would allow to prove that some particle went back in time, and changed state of something before it was used, but in such way that it would be impossible for us to act upon said change of state? For example (simplified/layman version): Blackbox where dice is dropped, regardless of its result, an event A is executed if the number is odd, event B of it's even. At the same time, before dice touches the ground, event C is executed. Event A is a light sent through A slit inside the Blackbox onto a detector. Event B is null, no light being sent. Event C is light sent through slit B inside the Blackbox onto a detector. Everything is recorded and available only after the experiment took place. Expected result, perhaps after 1000's of tries, would show some slight interference pattern being detected? This of course is just simple double-slit event experiment. Perhaps there are some other events that are suspected to produce particles that could possibly go back in time, and base the Blackbox setup on that. Anyway, general idea is to make a setup where event A or B happens regardless of C and A B C take place before ANY action can be made by observers.

[kamill85]

If you jump around different coordinates in space, via worm-hole or a warp-drive, these paradoxes do no apply. There is no acceleration work being done. You take a patch of space (your ship and then some space around it) from place X and basically "teleport" it to a place Y. Clock speed/rates are NOT affected. Time on board such ships goes at same rate as at the place it started from.

As I have told this to WarpTech repeatedly, the time experienced by the people on board the ship is unrelated to the paradoxes. Unless the existence of the wormhole you used prevents the creation of a wormhole by another ship, it is trivial to implement the paradox.
...

Uh, yes it matters. As in the Twin Paradox, it matters who is the observer and who is changing from the observer time-reference by doing acceleration work. In the A-FTL case there is NO acceleration work being done. Their time remains in-sync regardless of the distance.

Adding a third object traveling at any speed (less than c) through space does not change anything nor opens door to any paradox.

Go read the descriptions of the paradox inducing situations early in this thread. The amount of time experienced by the people travelling does not matter. Keep rereading the descriptions until you get that, because if you still think otherwise you have not understood them. If you build a wormhole/warp bubble that takes you 100 light years away in 1 year (so that when you arrive you see light from 99 years before you left) but gravitational time dilation as you pass through makes you age 1000 years, this does not change the paradox. The additional object travelling at a different speed using its FTL can leave after you arrive, and arrive before you left.

FTL "with space"  (the Apparent FTL) - for example a warp bubble that moves surrounding space around it-self, does NOT do any acceleration work. The clock ticks EXACTLY at same rate as at the starting point. There are no paradoxes coming out of it. No way to send messages to the past, nothing. A-FTL ship could be here 10:00, next moment jump 1 million ly away from us, spend 5 minutes there, jump back and it would be 10:05 here. This is how it would work (not saying that it will, just how the idea behind it works). Third observer traveling at any speed (less than c, say 0.7c), witnessing that coffee break 1 million ly away, wouldnt be able to send any message back in time to us, as anything he would have sent would arrive at best 1 million years later

The last statement is obviously wrong, since you already presumed that "bubble FTL" is possible. Therefore third observer's message, if sent using "bubble FTL" craft, CAN arrive sooner than 1 million years later.

If you read again, carefully this time, you would notice I said that ship can't do it, not that it's not possible. Said ship is traveling at 0.7C while passing by the coffee break event. Said ship can only keep flying at 0.7C in our direction or send some message at speed=C at best. So a message can arrive, again, at best in 1 million years after the coffee break took place, or 1.42million years later if delivered in person by the crew of said observer ship (ignoring space expansion).

That being said, why are you arguing over such tiny details? Do you like arguing for no reason? Trying to nitpick something someone said to point out possible statement error doesn't look good.

He is not nitpicking a tiny detail, and you did not seem to even understand what he said.

The other ship also would have FTL capability.

"Said ship can only keep flying at 0.7C in our direction or send some message at speed=C at best"
This sentence ignores the 3rd option that the other ship uses its own FTL. Using its own FTL will result in it travelling to the distant past on Earth because it has a different definition of simultaneous.

What third option? I clearly said that observer ship travels at 0.7c. If it had FTL, it would be different, but I said it's 0.7c so why make up options? And I used 0.7c because it was the speed I believe you used yourself in some of the examples. I did understand what he said perfectly.

At school exam, when teacher tasked you to solve some task, where "train goes at 100km/h and ...", did you also try to be smart and say "yeah but it could also go at 120km/h!", sure it could, but that's not the case in situation you've been tasked with, so no point in making such option(s).

Next, I do understand what you said about the observer traveling at 0.7c by the coffee event and THEN using the bubble FTL to go to us. Yes, his bubble encapsulates different time-reference, but the moment he switches off the A-FTL, everything will move away from him at 0.7c. Any message sent will be delayed a bit, and that bit happens to be exactly what would prevent him from sending a message back in time, even by a tiny bit.

[meberbs]

I didn't describe FTL communications, I described FTL travel.

FTL travel trivially allows FTL communication. This is not a meaningful distinction.

I'm describing going into the observer's future and seeing light from the target's past.  THe FTL ship is the observer. Earth is the target. If I warp out a distance, I see Earth's past, but I can't communicate what I see about Earth's past to Earth in the past, I can only communicate what I see of Earth's past to Earth in the present. thus no paradox for FTL ships.

None of what you are describing has any relation to the paradoxes. Go read the first 2 pages of the thread, at least through the worked examples.

Why FTL is even discussed at this point, of course any FTL transmission would travel back in time, math supports it, diagrams support it, experiments, well, do not support it as we are not sure how to make one. No need any third observer to prove/discover paradoxes. I'm talking about FTL through space of course.

No, actually. I am aware of no situation where a single FTL event (travel or just a message makes no difference) can result in a paradox. Either their needs to be another ship/ansible/whatever travelling at a different velocity, or the first one needs to chane its velocity and then do its FTL thing again.
Your misuse of "Apparent FTL" does not change this. Warp bubbles and wormholes still have the same problems with FTL.

Also, as to your whole sidenote, it has been experimentally demonstrated repeatedly. Look up tests of Bell's inequality, which demonstrate that quantum mechanics is without a doubt non-local, but in a way that can't transmit useful information, so it can't break causality.