Q: "Time Dilation: Faster = Longer Wait?

[Vandam]

I agree. And yet, there is no experimental evidence which can select the LET mumbo jumbo over the block universe mumbo jumbo.

I wonder what you exactly mean by 'experimental evidence'. That includes observation and measurements. We then have to agree on what you observe. Without observer independent events you only will end up in some bizarre philosophical interpretations such as solipsism. And if you do accept observer independent events as Einstein saw it (he was a realist and not a solipsist) it leads automatically to block universe.

Lorentz admitted that LT time-coordinates can not work in an ether (LET) context. LET with LT is a contradiction in terms. If you think you know better than Lorentz himself you have to do more work to convince me.

 

[Vandam]

Here is what I mean.
Green is the ether world. If you put green's coordinates of event A (0.5, 0.5) in the LT it gives you the red coordinates (Lorentz' local time) (0,289, 0,289).
The red coordinates (time and space dimensions) have no meaning at all in the green ether context. Not even if you consider the green ether through event R3.
In LET only the green coordinates have a physical meaning. Not the red ones. For the red ones you have to consider a physical red 3D world through R3 and A, which Einstein's SR allowed, but not Lorentz' LET.
That's why Lorentz said:
<<The chief cause of my failure was my clinging to the idea that the variable t only can be considered as the true time and that my local time t' must be regarded as no more than an auxiliary mathematical quantity. In Einstein's theory, on the contrary, t' plays the same part as t; if we want to describe phenomena in terms of x'; y'; z'; t' we must work with these variables exactly as we could do with x; y; z; t.>>
The LT only have a full physical meaning in SR, not LET.

 

[Dale]

I wonder what you exactly mean by 'experimental evidence'. That includes observation and measurements.

Yes, exactly. And LET predicts the exact same observations and measurements in all situations as does the block universe. Thus there can never be any experimental evidence distinguising the two, regardless of your philosophical preferences and arguments.

 

[bobc2]

Yes, exactly. And LET predicts the exact same observations and measurements in all situations as does the block universe.

How do you square that with the obvious: A 3-D universe evolving in time is physically not the same as a 4-D universe that is "...just all there." Or, "...things do not happen, they are just there."

Thus there can never be any experimental evidence distinguising the two, regardless of your philosophical preferences and arguments.

Except that LET is not consistent with the results of entanglement experiments, whereas the block universe is.

And again, the block universe is more fundamental as compared to the ad hoc LET. It's a little bit like the difference between the heliocentric model of our solar system vs. the mathematical model of the Earth centered solar system with cycles and epicycles, etc.

 

[Austin0]

Here is what I mean.
Green is the ether world. If you put green's coordinates of event A (0.5, 0.5) in the LT it gives you the red coordinates (Lorentz' local time) (0,289, 0,289).
The red coordinates (time and space dimensions) have no meaning at all in the green ether context. Not even if you consider the green ether through event R3.
In LET only the green coordinates have a physical meaning. Not the red ones. For the red ones you have to consider a physical red 3D world through R3 and A, which Einstein's SR allowed, but not Lorentz' LET.
That's why Lorentz said:
<<The chief cause of my failure was my clinging to the idea that the variable t only can be considered as the true time and that my local time t' must be regarded as no more than an auxiliary mathematical quantity. In Einstein's theory, on the contrary, t' plays the same part as t; if we want to describe phenomena in terms of x'; y'; z'; t' we must work with these variables exactly as we could do with x; y; z; t.>>
The LT only have a full physical meaning in SR, not LET.

It is true that Lorentz considered "the idea that the variable t only can be considered as the true time and that my local time t' must be regarded as no more than an auxiliary mathematical quantity. And SR considers both equivalent. But what that means is that SR considers BOTH t and t' as simply mathematical quantities with no implication that either one was "true" time or defining actual or physical simultaneity.

So your implication that SR considers t and t' as absolute in the sense Lorentz meant is not logically valid and in fact is antithetical to SR as it depends on the idea of an absolute scale or reference. You can interpret Einsteins thoughts as meaning conventionally synchronized clocks define actual or absolute simultaneity , which is the basis of your interpretation of Block Time but I don't think you can back up that interpretation with Einstein's actual statements and I flatly don't believe it. It seems fundamental to SR that simultaneity is totally indeterminate and relative with the exception of co-located events.

It is true that SR denies the classical concept of a universal or absolute now but it does not replace it with a set of many universal or absolute "nows" . One for every velocity.

In actuality SR does not explicitly negate the possibility of a universal "now" it simply shows that any such instant is indeterminate and thus superfluous. Like an ether, or absolute motion.

Even given a hypothetical persistent and pre-created 4-d continuum , it is clear that consciousness exists in a limited slice of time and so in effect moves. SO there is neither any objection to the possibility that all consciousness is absolutely simultaneous. I.e a single slice of awareness progressing through the continuum nor any means of empirically falsifying such a concept.
It is self evident that the various clocks throughout the universe would not correspond to this simultaneity but how could this be observed or measured within the structure?

There may be a number of people who are open to the possibility of Block time in some form ( I don't completely reject it) but I would be surprised if there are many people who understand SR who consider conventionally synchronized clocks to be absolutely simultaneous.
WHich is exactly what you are claiming wouldn't you agree?

 

[Dale]

How do you square that with the obvious: A 3-D universe evolving in time is physically not the same as a 4-D universe that is "...just all there." Or, "...things do not happen, they are just there."

It isn't obvious to me. If a 3D evolving universe were physically different from a 4D universe then I would expect there to be some testable consequences, which there aren't. So I think they are philosophically different but physically identical.

Except that LET is not consistent with the results of entanglement experiments, whereas the block universe is.

Please provide a mainstream scientific reference for this claim. Since both LET and QFT use the LT your claim seems patently false to me.

And again, the block universe is more fundamental as compared to the ad hoc LET.

I agree completely, but this is a philosophical or aesthetic preference.

 

[bobc2]

No, LET is consistent with entanglement since the LT is used by modern QFT.

That does not imply that LET is consistent with results of entanglement experiments. On the contrary, LET specifically requires light cone causality--that's the basis of Lorentz's derivations. That's why LET is tied directly to a 3-D universe evolving in time model. Entanglement experimental results violate light cone causality. Violation of light cone causality is not a problem for the block universe model. Thus, results of entanglement experiments provide the distinction you are looking for.

 

[PeterDonis]

Entanglement experimental results violate light cone causality.

No, they don't. You can't send signals faster than light by using entanglement. The statistical correlations between results *appear* to "travel faster than light", but that's only an appearance; when you work out the underlying quantum field theory, the field operators commute at spacelike separations, so light cone causality is obeyed.

Violation of light cone causality is not a problem for the block universe model.

It would be if it actually happened; the block universe model still depends on a well-defined light cone structure that determines causal relationships between events.

 

[Dale]

That does not imply that LET is consistent with results of entanglement experiments.

Yes, it does. Entanglement follows the LT, just as predicted by LET. That is the epitome of consistency.

PeterDonis already dealt with the rest of your post.

 

[Vandam]

Austin0,
Thanks for your reaction, I read it 4 times, but I am unable to understand what you exactly mean. I especially do not understand your 'absolute' and universal' terminology in the context what I mean. I think you didn't understand what I mean.
If my spacetime diagram is wrong , tell me where it is wrong.
How would you draw the spacetime diagram showing the Lt time coordinates?

Same advice for Dalespam.
If my spacetime diagram is wrong , tell me where it is wrong.
How would you draw the spacetime diagram showing the Lt time coordinates?
You just keep on telling me that the LT transformations give the same result in LET and SR, but if you can not tell me where the primed time coordinates should be read on a simple ether space and time diagram I am not impressed with your statement.

 

[bobc2]

No, they don't. You can't send signals faster than light by using entanglement. The statistical correlations between results *appear* to "travel faster than light", but that's only an appearance; when you work out the underlying quantum field theory, the field operators commute at spacelike separations, so light cone causality is obeyed.

You are missing the whole point of my comments. I didn't say that signals are sent faster than light with entangled particles. It is for exactly that reason that LET fails with entanglement experiments. LET was developed specifically for explaining related events via the model of a fixed ether through which all processes evolve as a result of signals transmitting at the speed of light as ether waves.

Processes involving entangled particles at a distance (not local) simply do not fit that model. LET is inconsistent with that. A fixed ether medium does not work with quantum field theory. However, the block universe model is not at all inconsistent with that.

It would be if it actually happened; the block universe model still depends on a well-defined light cone structure that determines causal relationships between events.

It certainly does not. The worldlines of the elementary particles are all there in the 4-dimensional structure. They can begin anywhere and end anywhere QM and QFT would like. It has no constraints by a fixed ether which includes only light cone causal influences.

 

[PeterDonis]

I didn't say that signals are sent faster than light with entangled particles. It is for exactly that reason that LET fails with entanglement experiments. LET was developed specifically for explaining related events via the model of a fixed ether through which all processes evolve as a result of signals transmitting at the speed of light as ether waves.

I don't understand your point. You agree that entanglement doesn't send signals faster than light; and you say LET doesn't involve sending signals faster than light. So where's the discrepancy?

entangled particles at a distance (not local)

If entanglement can't be used to send signals faster than light, then it *is* local. That's the whole point. "Local" in a relativistic theory is indistinguishable from "causal". In the quantum version, "local" means "field operators commute at spacelike-separated events", which is the same as "causal".

A fixed ether medium does not work with quantum field theory.

Sure it does. See above.

The worldlines of the elementary particles are all there in the 4-dimensional structure. They can begin anywhere and end anywhere QM and QFT would like.

Which means they can only embody causal relationships permitted by QM and QFT. You seem to have a misconception that QM and QFT somehow relax the rules about causal relationships between events. They don't. The observed worldline of a particle with nonzero rest mass can still only be a timelike worldline. You can have "virtual" worldlines for the particle which are not timelike (at least, that's how the "sum over histories" view of QFT would describe it), but their amplitudes will always cancel out in the observable; the observed worldline can only be timelike.

 

[Dale]

If my spacetime diagram is wrong , tell me where it is wrong.

I never said your diagram was wrong. Do you think that I did?

Regarding impressing you, frankly it isn't a requirement for being right.

 

[Vandam]

I never said your diagram was wrong. Do you think that I did?

If you accept my diagram you can not say that the LT make sense in LET.
So there's a contradction in terms.
Don't you see that?

 

[zonde]

Here is what I mean.
Green is the ether world. If you put green's coordinates of event A (0.5, 0.5) in the LT it gives you the red coordinates (Lorentz' local time) (0,289, 0,289).
The red coordinates (time and space dimensions) have no meaning at all in the green ether context. Not even if you consider the green ether through event R3.
In LET only the green coordinates have a physical meaning. Not the red ones. For the red ones you have to consider a physical red 3D world through R3 and A, which Einstein's SR allowed, but not Lorentz' LET.
That's why Lorentz said:
<<The chief cause of my failure was my clinging to the idea that the variable t only can be considered as the true time and that my local time t' must be regarded as no more than an auxiliary mathematical quantity. In Einstein's theory, on the contrary, t' plays the same part as t; if we want to describe phenomena in terms of x'; y'; z'; t' we must work with these variables exactly as we could do with x; y; z; t.>>
The LT only have a full physical meaning in SR, not LET.

The red sentence is wrong.

Red coordinates provide valid account of measured time and distance with rulers and clocks (brought) at rest in that coordinate time. In green coordinate system we have to add specific law in order to predict elapsed time on a moving clock (given we know elapsed time on the same clock when it is brought at rest in green coordinate system).

 

[zonde]

Except that LET is not consistent with the results of entanglement experiments, whereas the block universe is.

As long as there are no loophole free Bell test there is no confirmed conflict with relativity.

But if you mean that block universe is consistent with QM predictions about entanglement then I would like to see how you arrived at that. Because you see block universe by itself does not tell anything. You have to equip it with physical laws that are consistent with know experimental results. And as you do that you effectively restrict what types of patterns are allowed in your block universe. And you can't model QM predictions using these allowed patterns.

 

[Vandam]

The red sentence is wrong.
Red coordinates provide valid account of measured time and distance with rulers and clocks (brought) at rest in that coordinate time.

That's exactly what I show. The red clocks do not move in red frame (world)

In green coordinate system we have to add specific law in order to predict elapsed time on a moving clock (given we know elapsed time on the same clock when it is brought at rest in green coordinate system).

Sorry, but where do copied this nonsense from? Do you understand yourself what you wrote there?

Please show me on the ether space and time diagram in which green ether space the red time coordinates are valid!

Let me elaborate a bit on my diagram to be sure the message gets across.
(It would have been better if I had sketched a loedel diagram in which the time and space units are equal, but I doubt most forum members are familiar with loedel diagrams...).

When the green ether observer has 0,5 on his wristwatch, the Red traveler's clock shows 0,433. Red clok runs slow. Red is at planet Q. The distance between the red traveler and event A (light at the star) is O,25.

The LT transfomation (event A's time and space coordinates for red) tells us what red observer will experience: at 0,289 on his wristwatch event A (light at the star) is located (3D space distance) at 0,289 from him.

How can red's scenario work in the ether? It cannot.

Do you perhaps want to replace the content of R4 wit that of content R3? red's wristwatch time indication of event R4? That's impossible: at R4 Red traveler with wristwatch 0,289 is at planet Q and not at planet P.
Red's wristwatch on 0,289 is in the green ether through that event R3, but in that ether Red traveler still can not measure the 3D space distance to A. Event A is not (yet) part of that green ether world!
The LT result only works in SR: Red traveler has his own 3D world 'in which' he measures 0,289 space dimension between the simultaneous events R3 and A.

(You might (but I doubt) get LT to work in a LET context if you question the existence of observer independent events, etc, but then you slide into solipsim or other bizarre philosophical approaches that are not necessary in SR.)

 

[Vandam]

As long as there are no loophole free Bell test there is no confirmed conflict with relativity.

But if you mean that block universe is consistent with QM predictions about entanglement then I would like to see how you arrived at that. Because you see block universe by itself does not tell anything. You have to equip it with physical laws that are consistent with know experimental results. And as you do that you effectively restrict what types of patterns are allowed in your block universe. And you can't model QM predictions using these allowed patterns.

I think Bob means this.
How can an observation of a particle, causing the collapse of the wavefunction, have an immediate impact on a simultaneous space-like event: (the twin 'entangled') particle?
LET can not give an answer because you need faster than light communication (even immediate communication!). Hence LET is not compatible with QM.
Block Universe solves that problem, because ALL the events, future, space-like or not, pre-exist. We only discover them as time goes by. So there has not to travel any information at all beween the entangled particles or events. Causal relationship between entangled particles is not necessary in Block Universe. (In Block universe the events are not 'caused' by (a) previous event(s); the causal relationschip is deducted from discovering a sequence of pre-existing events. But QM tells us that apparently (some?) QM events have no causal relationships. Bock universe can deal with that. Not LET (altough a 'Block ether universe' (!) might work, but that's still not compatible with SR.)
Block universe does not work with 'probabilities' or collapsing of wavefunctions'. These are only manmade tools to calculate, predict, or 'guess' the future 3D worlds. And because we do not know (yet?) precisely why Block Universe has those 'QM' entangled space-like events located there where they are, we do our best with the probabilities and wavefunctions to predict which QM events our 3D world will encouter.
Bob, I hope I didn't shake too much your QM line of thought with all this?

 

[Dale]

If you accept my diagram you can not say that the LT make sense in LET.
So there's a contradction in terms.
Don't you see that?

No, I don't see that. Your diagram seems to follow the LT.

Do you believe your diagram violates the LT? If so, please point out the offending feature because I missed it.

 

[zonde]

Red's wristwatch on 0,289 is in the green ether through that event R3, but in that ether Red traveler still can not measure the 3D space distance to A. Event A is not (yet) part of that green ether world!
The LT result only works in SR: Red traveler has his own 3D world 'in which' he measures 0,289 space dimension between the simultaneous events R3 and A.

Okay I think I see where is your problem. You see we learn about event A only when light from that event have reached us.

So it is of little importance that this event has not yet happened because it can't affect us before some future point R5 where our worldline crosses future light cone of A.

 

[Vandam]

No, I don't see that. Your diagram seems to follow the LT.

Do you believe your diagram violates the LT? If so, please point out the offending feature because I missed it.

Haha. That's the best one! You make my day!

Can you at least recognize the ether in my drawings. Can you?

I'm afraid I may draw 100 diagrams and write 100 pages of text, it won't help you.

Hopeless. Really hopeless.

Please show me where on an ether'space and time' diagram (for the ether scenario a real 'spacetime' diagram doesn't make sense) the LT time (and space) coordinates make sense.

 

[Dale]

Can you at least recognize the ether in my drawings. Can you?

Yes, you clearly labeled it.

Please show me where on an ether'space and time' diagram (for the ether scenario a real 'spacetime' diagram doesn't make sense) the LT time (and space) coordinates make sense.

Exactly how you showed them. The green coordinates are the aether coordinates and the red coordinates are the local coordinates, related to the aether coordinates by a Lorentz transform.

Look, you may not like it, but LET is an interpretation of the LT. Specifically, it is the interpretation of the LT where one frame is uniquely designated as the aether frame and the other frames (all related to the aether frame by the LT) are designated as "local coordinates" instead. So your diagram cannot violate LET without drawing something contrary to the LT, which I don't see drawn.

You appear to be committing a strawman fallacy (http://www.fallacyfiles.org/strawman.html). There exists an interpretation of the LT wherein one frame (the aether frame) is singled out as uniquely representing the state of the 3D universe which is evolving in time, and other coordinate systems (local frames), not representing the state of the 3D universe, are related to the aether frame via the LT. If you are addressing some other theory which does not use the LT for its predictions then you are addressing a strawman that you have set up and not my argument.

 

[zonde]

So there has not to travel any information at all beween the entangled particles or events. Causal relationship between entangled particles is not necessary in Block Universe. (In Block universe the events are not 'caused' by (a) previous event(s); the causal relationschip is deducted from discovering a sequence of pre-existing events. But QM tells us that apparently (some?) QM events have no causal relationships. Bock universe can deal with that. Not LET (altough a 'Block ether universe' (!) might work, but that's still not compatible with SR.)

Causality is not absent from block universe. It is present as certain pattern in events.

Well of course you can claim that there can appear about anything you fancy in block universe but in that case you are not talking science. In order for your ideas to be scientific they should follow certain rules. And concept of block universe that follows these rules does not allow just anything you fancy in it.

 

[Vandam]

Okay I think I see where is your problem. You see we learn about event A only when light from that event have reached us.

I think not I but you have a problem: you insinuate that event A doesn't exist before we see it! Be careful. That leads to solipsism. That's metaphysics.

So it is of little importance that this event has not yet happened because it can't affect us before some future point R5 where our worldline crosses future light cone of A.

What you tell here has nothing to do with SR.
It has nothing to do with 'what can affect us or not'. That's not what SR is about.
You are too much concentrated on your lightcone.

Do you believe in an observer independent simultaneous space-like event before you see anything of it?
Do you believe in a 3D world made of observer independent events?

SR works with observer independent events.
Einstein was a realist, not a solipsist:

Einstein quotes:
"Belief in an external world independent of the perceiving subject is the basis of all natural science."

"Physics is an attempt conceptually to grasp reality as something that is considered to be independent of its being observed. In this sense one speaks of 'physical reality.'”

“I am not a positivist. Positivism states that what cannot be observed does not exist. This conception is scientifically indefensible, for it is impossible to make valid affirmations of what people 'can' or 'cannot' observe. One would have to say 'only what we observe exists', which is obviously false."

<As always the conception of the existence of the real world is fundamental in physics. Without is there would be no borderline between psychology and physics. ... Modern developments have changed nothing in this respect."

"The belief in an external world independent of the perceiving subject is the basis of all natural science."

 

[Vandam]

Yes, you clearly labeled it.

Exactly how you showed them. The green coordinates are the aether coordinates and the red coordinates are the local coordinates, related to the aether coordinates by a Lorentz transform.

Look, you may not like it, but LET is an interpretation of the LT. Specifically, it is the interpretation of the LT where one frame is uniquely designated as the aether frame and the other frames (all related to the aether frame by the LT) are designated as "local coordinates" instead. So your diagram cannot violate LET without drawing something contrary to the LT, which I don't see drawn.

I do not have to like it either.
Designating one frame as the ether frame and not the other is exactly what Lorentz mistake was. And he admited he was wrong:

<<The chief cause of my failure was my clinging to the idea that the variable t only can be considered as the true time and that my local time t' must be regarded as no more than an auxiliary mathematical quantity. In Einstein's theory, on the contrary, t' plays the same part as t; if we want to describe phenomena in terms of x'; y'; z'; t' we must work with these variables exactly as we could do with x; y; z; t.>>

The LT only have a full physical meaning in SR, not LET.

You simply do not get the essence of SR.

 

[Mentz114]

Okay I think I see where is your problem. You see we learn about event A only when light from that event have reached us.

I think not I but you have a problem: you insinuate that event A doesn't exist before we see it! Be careful. That leads to solipsism. That's metaphysics.

That is not what he said ! Troll tactic.

So it is of little importance that this event has not yet happened because it can't affect us before some future point R5 where our worldline crosses future light cone of A.

What you tell here has nothing to do with SR.
It has nothing to do with 'what can affect us or not'. That's not what SR is about.
You are too much concentrated on your lightcone.

What rubbish. Of course SR is a about causality and what can affect us.

You simply do not get the essence of SR.

Once again your claim is rubbish. You are not the only person who understands these things. In your case I use the word 'understanding' with reservation.

 

[Dale]

Designating one frame as the ether frame and not the other is exactly what Lorentz mistake was. And he admited he was wrong:

Perhaps he was wrong in a philosophical sense, but there isn't any empirical evidence that he was wrong. That is the thing that you seem unable to understand, the distinction between philosophy and evidence.

The LT only have a full physical meaning in SR, not LET.

Having "a full physical meaning" is another unnecessary philosophical consideration. As long as the predictions agree with experiments then it is scientifically irrelevant if local coordinates do not have "a full physical meaning". The evidence simply cannot distinguish between the block universe interpretation and the aether interpretation of the LT.

 

[zonde]

Do you believe in an observer independent simultaneous space-like event before you see anything of it?
Do you believe in a 3D world made of observer independent events?

Yes. I might be open to other possibilities but I consider them quite exotic.

SR works with observer independent events.
Einstein was a realist, not a solipsist:

Einstein quotes:
"Belief in an external world independent of the perceiving subject is the basis of all natural science."

"Physics is an attempt conceptually to grasp reality as something that is considered to be independent of its being observed. In this sense one speaks of 'physical reality.'”

“I am not a positivist. Positivism states that what cannot be observed does not exist. This conception is scientifically indefensible, for it is impossible to make valid affirmations of what people 'can' or 'cannot' observe. One would have to say 'only what we observe exists', which is obviously false."

<As always the conception of the existence of the real world is fundamental in physics. Without is there would be no borderline between psychology and physics. ... Modern developments have changed nothing in this respect."

"The belief in an external world independent of the perceiving subject is the basis of all natural science."

Yes. Quite natural position for physicist.


After a bit of thinking - maybe you equate coordinate system with simultaneity of that coordinate system?
In that case it would make sense to say that simultaneity of non aether frame has no physical meaning.

But if that is the case I would like drop out of discussion because while I privately might prefer to model the world as having one "right" simultaneity I like to keep out of discussions that can't be resolved by means of experiments and observations.

 

[Vandam]

Having "a full physical meaning" is another unnecessary philosophical consideration.

Of course. You call everything that does not apprear on your calculator a philosophical consideration.
Nice physics!
Look, I am not prepared to discuss physics on that bases. I consider this discussion closed. Good luck.

 

[PeterDonis]

How can an observation of a particle, causing the collapse of the wavefunction, have an immediate impact on a simultaneous space-like event: (the twin 'entangled') particle?

Why do you think it does? First of all, you're assuming that there is a collapse of the wavefunction; there is at least one QM interpretation, the many worlds interpretation, which has no collapse of the wavefunction. (And I think you will find that many physicists who believe in the "block universe" also believe in the MWI.) Second, even on a "collapse" interpretation, you're assuming that the collapse is "something real" that travels faster than light between the two entangled particles; but as I noted and bobc2 agreed, you can't send signals faster than light using entanglement, so the only thing that actually "travels faster than light" is a statistical correlation, which is not a "real thing". All causal influences still travel at the speed of light or slower.

LET can not give an answer because you need faster than light communication (even immediate communication!).

No, you don't. Entanglement doesn't let you communicate faster than light. See above.

Block Universe solves that problem, because ALL the events, future, space-like or not, pre-exist.

In your *model*, yes. In the *real world*, you don't know that this is true.

Causal relationship between entangled particles is not necessary in Block Universe.

If by "block universe" you just mean "a 4-D manifold with no constraints", then yes, I suppose this is correct. But if by "block universe", you mean "a 4-D manifold that obeys the laws of Special Relativity", which is the only kind of "block universe" that is consistent with experiments, then no, this is not correct. Causal relationships still exist between events in a block universe that is consistent with SR; if they didn't, it wouldn't be consistent with SR.

Have you read Julian Barbour's writings on time? He has done a *lot* of work on thinking out exactly what a "timeless" view of physics, which is basically the kind of "block universe" viewpoint you are advocating, involves. I think you would find his writings on this subject very interesting.

http://www.platonia.com/papers.html

In Block universe the events are not 'caused' by (a) previous event(s); the causal relationship is deducted from discovering a sequence of pre-existing events. But QM tells us that apparently (some?) QM events have no causal relationships.

No, QM does not tell us that. A causal relationship is a geometric relationship between events; events that are timelike separated or null separated are causally related, and events that are spacelike separated are not. QM, or more properly quantum field theory, does not change anything about causal relationships; QFT is still set in 4-D spacetime and events are still either timelike, null, or spacelike separated.