Bump.

In the philosophy of time, there are two major positions, the A-theory and the B-theory. The A-theory is often considered to be in line with the traditional view on time, where things change in accord with the passage of time and reality is dynamic. The B-theory on the other hand does not take the passage of time to be real at all and considers all events often taken to be past, present, and future, to be real in a static block universe. — Mr Bee

A terminology note. The A/B this is more correctly known as A-series and B-series, and they're not a philosophical stance, just a relative vs. more absolute way to speak of time.

The philosophical positions you are describing is presentism and eternalism, with the former asserting a flowing preferred moment in time separating all events into 3 distinct ontological states of happened, happening, and yet to happen. The latter gives equal ontological status to all events and disallows references to the nonexistent preferred moment.

Essentially I want to argue that the A-theory is better at accommodating certain features of time, those which seem to depict it time as flowing series of events, that would give reason to support it. — Mr Bee

It is certainly more practical, which is why A-series is used in everyday language and intuition. I can similarly argue that B-series gives a more practical framework in which physics can be discussed. But lacking an empirical distinction between the two, I don't see a proof being likely. Everyday life can be awkwardly described in B-series, and physics can be awkwardly described in A-series.

- History: The most defining feature of time is the fact that it describes the different states of the universe. If you were to take one slice of time and another, you would find that they contain the same matter and objects, just organized differently.

I can say the same with slices of space. The word 'history' carries an implication of a past, which is a presentist interpretation.

- Connectivity: There is a relation between adjacent times that we capture through the laws of nature. The slices of time and states of the universe are not just ordered arbitrarily, where each time is completely independent of the other, but they are connected together in specific ways (for instance, the state of the universe in 2018 would not be adjacent to a state very early in the universe's history in time).

Spacetime has connectivity yes. Calling them slices is from the eternalist interpretation. The presentist would only have the one current state of space, with no other 'slices' to connect with it.

- Linearity: We often talk about time as a line going from one end to the other. Unlike space, which contains three dimensions, time is one dimensional.

It isn't a dimension at all if time flows. 4D spacetime can have all four axes oriented arbitrarily, so yes, there's one time axis, but its orientation is arbitrary within the confines of the speed of light. Rotate beyond that, and a different axis assumes the role of the time axis. Fun factoid: This switching of roles of axes actually happens in black holes, which I think don't exist yet under presentism.

- Order: Under time there is also a preferred direction, which some refer to as the "arrow of time". We talk of events going from 2000 to 2001 but never the other way around.

Entropy defining the direction of the arrow. If entropy stabilizes, there would be no arrow.

It is these four features of time that I take to be better accounted for in the A-theory than in the B-theory. As far as I am aware of there is no explanation of why time is structured the way that it is in the latter.

Both account for it all just fine.

Why is time a series of slices depicting the history of the same 3D universe?

??? It isn't in either view. The former has no slices, just a changing 3D state. The latter has a block with no slices other than abstracted considerations that can be oriented any way one chooses, similar to the way the 3D universe has no mandatory choice for the X axis.

Why is there only one dimension of time and three (or more if we take string theory into account) of space?

From what I've read on inflation theory, this is chance. There are a lot of dimensions and some inflation bubbles have different numbers of macroscopic spatial and time dimensions. So maybe one bubble has 2 spatial and 3 time dimensions. Only the 3/1 configuration seems to allow the sort of physical mechanics that permits complex structures like atoms to form. Most of those strangely configured bubbles collapse immediately or explode into featureless fog. That 3/1 bit is part of a much longer list of tunings required to allow us to exist.

None of that answer really applies to presentism, which puts time outside the universe. There is no inflation theory under presentism that I know of, so the problems solved by it remain unsolved in the presentist view. The tuning problem is one of them.

Under the B-theory, all of the features seem to only be taken as a given in the block universe. It seems as though all events are simply laid out the way that they are with the relations between them, as a brute fact.

There is still quantum indeterminacy, so no brute fact implied by the block. A lot here depends on your quantum interpretation of choice. Hard determinism seems to be what you're describing here, and both time interpretations allow it but don't assert it.

If you're a B-theorist or at the least are actually familiar with the views, then I am interested in hearing from you.

I prefer the eternal model, but I don't assert that the presentist model is wrong.

The philosophical positions you are describing is presentism and eternalism, with the former asserting a flowing preferred moment in time separating all events into 3 distinct ontological states of happened, happening, and yet to happen. The latter gives equal ontological status to all events and disallows references to the nonexistent preferred moment. — noAxioms

Not really. The A-theory as I described it is meant to encompass all forms of the view, including the Moving-Spotlight and Growing Block views. If it was Presentism I was referring to exclusively, then I would've specified that only the present exists when describing that view. As for the B-theory being equated to Eternalism, that would be true simply because there are no other versions of the B-theory that people take seriously.

The A-theory and B-theory for the purposes of this thread deal with the reality of the flow of time. Issues pertaining to the ontology of time are irrelevant.

It is certainly more practical, which is why A-series is used in everyday language and intuition. I can similarly argue that B-series gives a more practical framework in which physics can be discussed. But lacking an empirical distinction between the two, I don't see a proof being likely. Everyday life can be awkwardly described in B-series, and physics can be awkwardly described in A-series.

Note that first, I am not claiming to provide a proof of the A-theory, just an argument in it's favour.

Second, the features that I am claiming here are accepted even in the context of physics. The laws of nature operate on the assumption that time is a connected linear series of events describing the story of the same universe.

Finally, third, your argument for the B-theory pertains to a practical argument based upon it's usefulness in physics, while mine is an argument from explanation. Two different types of arguments.

I can say the same with slices of space. The word 'history' carries an implication of a past, which is a presentist interpretation.

How so? I'm curious to see you try. What exists in space can be completely random. They do not all represent different versions of the same object. However, the red ball at t1 and the red ball at t2 apparently do and we describe it as such. Space defines what things exist, while time defines how they exist.

Spacetime has connectivity yes. Calling them slices is from the eternalist interpretation. The presentist would only have the one current state of space, with no other 'slices' to connect with it.

The Presentist (nor the A-theorist) would not disagree with the representation of time as we normally understand it, where adjacent events are related to one another via causality. They would still understand time as a series of interconnected events.

It isn't a dimension at all if time flows.

Why? The Presentist (nor the A-theorist) again does not disagree with the representation of time as a linear series of events, so whether they all exist together or occur one by one is irrelevant. It wouldn't be a dimension like space of course but that is not to say that it cannot be described as a dimension at all.

4D spacetime can have all four axes oriented arbitrarily, so yes, there's one time axis, but its orientation is arbitrary within the confines of the speed of light. Rotate beyond that, and a different axis assumes the role of the time axis.

That is irrelevant, since it doesn't change the fact that there is only one time dimension in contrast to the three dimensions of space.

Entropy defining the direction of the arrow. If entropy stabilizes, there would be no arrow.

The objective status of the arrow of time isn't completely settled, so that is one area that I am willing to grant may not hold. However, that still leaves the other three features left unaccounted for.

Both account for it all just fine.

The question is not whether the B-theory is able to account for it. It can accommodate it simply by positing it as a brute fact about the nature of time, but that doesn't make it equal in strength to the A-theory's account of it, which I argue here explains it better.

??? It isn't in either view.

Really? It seems very obvious that time is a series of events.

The former has no slices, just a changing 3D state. The latter has a block with no slices other than abstracted considerations that can be oriented any way one chooses, similar to the way the 3D universe has no mandatory choice for the X axis.

As stated before, the Presentist would still agree that time can be described with the features mentioned above. As for Eternalism, the fact that, under relativity, we can slice spacetime up in practically an inifnite number of ways does not change the fact that no matter how we look at it (under any given slicing), that time is a series of 3D slices of space.

From what I've read on inflation theory, this is chance. There are a lot of dimensions and some inflation bubbles have different numbers of macroscopic spatial and time dimensions. So maybe one bubble has 2 spatial and 3 time dimensions.

Not sure about this. I've heard inflation being used as a way of solving the cosmological constant problem, but varying constants is not the same as varying dimensions of time. People have also spoken about the "dimensionality" varying between universes, but as far as I can tell, this "dimensionality" that people speak about as varying refers strictly to space (and even then it is only the apparent dimensionality that is claimed to vary), not time, which is what I am concerned about. Do you have a reference that says that the time dimension can vary across bubble universes?

Also given that inflation is a dynamical process, it should unfold in time no? If so, then I have trouble imagining how inflation would lead to the creation of universes with varying time dimensions given that the process of bubble universes being formed is something that occurs within a time dimension itself. Of course, it could be that I am misunderstanding something here, which is also a possibility.

The idea of a multiverse is still debatable (at least of the stronger forms involved here), but if there can be other universes that exist along our own that contain more than one time dimension (or none at all), then that would undermine the linearity feature of my argument.

Only the 3/1 configuration seems to allow the sort of physical mechanics that permits complex structures like atoms to form. Most of those strangely configured bubbles collapse immediately or explode into featureless fog. That 3/1 bit is part of a much longer list of tunings required to allow us to exist.

This just sounds plainly wrong to me. I don't see why life would require 3+1 dimensions in order to exist. For one, such an idea would falsify string theory on the basis that the latter requires alot more than 3 dimensions of space to even work, but I imagine that they wouldn't be persuaded to drop it based upon anthropological concerns. In addition, on the issue of time, I also fail to see why life would require a single dimension of time in order to operate. Although it isn't clear to me what it would exactly mean to say that there is more than one dimension to time I do not see what about it's nature would preclude conscious beings like us from existing in it. With respect to a world that contains no time at all, the same reasoning applies. It could be that that some form of temporal solipsism is true, where one 3D slice of time exists and only that time, but that time can in theory describe a world where living animals and conscious beings such as us exist.

There is still quantum indeterminacy, so no brute fact implied by the block. A lot here depends on your quantum interpretation of choice. Hard determinism seems to be what you're describing here, and both time interpretations allow it but don't assert it.

Don't see how quantum indeterminacy undermines or accounts for any of the features of time. A block universe with quantum indeterminacy (assuming that an indeterministic interpretation of QM is true) is still just as problematic as one that doesn't have it. Can you explain how it is relevant here?

I prefer the eternal model, but I don't assert that the presentist model is wrong.

Then you are a presentist then? My assumption is that you're a firm eternalist, but in that case, you would believe that presentism is wrong.

Note that first, I am not claiming to provide a proof of the A-theory, just an argument in it's favour.

Second, ...

Finally, third, your argument for the B-theory — Mr Bee

I said I wasn't arguing for it. Just comparing mostly.

How so? I'm curious to see you try.

I interpreted the comment wrong. I see what you're saying now.

It isn't a dimension at all if time flows. — noAxioms

Why? The Presentist (nor the A-theorist) again does not disagree with the representation of time as a linear series of events, so whether they all exist together or occur one by one is irrelevant. It wouldn't be a dimension like space of course but that is not to say that it cannot be described as a dimension at all.

The representation as a dimension would not reflect reality. Yes, it still can be useful to describe it that way.

Really? It seems very obvious that time is a series of events.

If there were no space, then yes, there would be just this linear series of events. But most pairs of events are ambiguously ordered (at least in the eternal model), so time would then not be a series of events. Time seems to be relevant only to causally related events, so time seem more to be a a product of a structure with causal relationships. That's how I tend to view it at least. YMMV.

The former has no slices, just a changing 3D state. The latter has a block with no slices other than abstracted considerations that can be oriented any way one chooses, similar to the way the 3D universe has no mandatory choice for the X axis. — noAxioms

As stated before, the Presentist would still agree that time can be described with the features mentioned above.

I would think not. If there is a present, it is an absolute state, however undetectable, and other abstract slices of the block are simply misrepresentations of reality. There is no arbitrary choice about it. An arbitrary guess if something preferred suggests itself, and yes, it does.
Maybe the present is some wrinkled wiggly thing. So long as it foliates a map of all events, it works.

As for Eternalism, the fact that, under relativity, we can slice spacetime up in practically an inifnite number of ways does not change the fact that no matter how we look at it (under any given slicing), that time is a series of 3D slices of space.

Well, you could slice across one of the other dimensions and get 2D space and 1D time.

Not sure about this. I've heard inflation being used as a way of solving the cosmological constant problem, but varying constants is not the same as varying dimensions of time.

There's a list of stuff that can vary, and a list that cannot. Yes, the cosmological constant is one, and the hardest one to get to a workable value if you're just pulling random values out of your arse. I guess that implies a lot of bubbles.

People have also spoken about the "dimensionality" varying between universes, but as far as I can tell, this "dimensionality" that people speak about as varying refers strictly to space, not time, which is what I am concerned about. Do you have a reference that says that the time dimension can vary across bubble universes?

Try this, which was the first item on my little google of it:
https://www.quora.com/If-there-are-3-physical-space-dimensions-why-arent-there-3-time-dimensions

The idea of a multiverse is still debatable (at least of the stronger forms involved here), but if there can be other universes that exist along our own that contain more than one time dimension (or none at all), then that would undermine the linearity feature of my argument.

Technically the bubbles relate, being part of one QM structure, so different worlds in one universe. But other bubbles have completely different physical laws (especially the classic laws), so most qualify them as other universes.

This just sounds plainly wrong to me. I don't see why life would require 3+1 dimensions in order to exist.

The article I linked gets into this.

For one, such an idea would falsify string theory on the basis that the latter requires alot more than 3 dimensions of space to even work,

Yes, but most of them not macroscopic. We're counting the macroscopic ones here.

I also fail to see why life would require a single dimension of time in order to operate. Although it isn't clear to me what it would exactly mean to say that there is more than one dimension to time I do not see what about it's nature would preclude conscious beings like us from existing in it.

I tried creating a simulation of that, and could only manage it with 1 space dimension.

With respect to a world that contains no time at all, the same reasoning applies. It could be that that some form of temporal solipsism is true, where one 3D slice of time exists and only that time, but that time can in theory describe a world where living animals and conscious beings such as us exist.

Makes no sense to me. You seem to describe a photo of a dog, which is not a living thing. It isn't life if there are no dynamics.

Don't see how quantum indeterminacy undermines or accounts for any of the features of time. A block universe with quantum indeterminacy (assuming that an indeterministic interpretation of QM is true) is still just as problematic as one that doesn't have it. Can you explain how it is relevant here?

Well, take the relational interpretation then, which has no meaningful state except as measured, and nothing measures the universe (the big bang is a point of view that sees nothing), so the universe has no state, just relations. Everett would say it has solutions to Schrodinger equations. Neither of those has meaningful state. The Bohmian interpretation has it (hard, single-outcome determinism), but it does so at the cost of cause before effect (locality). I personally find the latter more offensive, but that's just my taste.

I prefer the eternal model, but I don't assert that the presentist model is wrong. — noAxioms

Then you are a presentist then?

No, a presentist would not prefer the opposing model.

My assumption is that you're a firm eternalist, but in that case, you would believe that presentism is wrong.

I am a squishy eternalist. I only take firm stances against positions which don't seem self consistent.

The representation as a dimension would not reflect reality. — noAxioms

The representation would reflect reality as a dynamic succession of events. It would of course not reflect reality in the same way it would under the block universe, where time is all laid out like space, but that is not to say that it doesn't reflect the nature of the world.

If there were no space, then yes, there would be just this linear series of events. But most pairs of events are ambiguously ordered (at least in the eternal model), so time would then not be a series of events.

I believe you're focusing too much on the fact that there is no clearly preferred way of ordering events while ignoring the fact that no matter which way we do order them, space-time as a whole would be broken down to a series of events describing an evolving 3D universe.

Time seems to be relevant only to causally related events, so time seem more to be a a product of a structure with causal relationships. That's how I tend to view it at least. YMMV.

Even if you choose to view time in a local manner, I think that that is still enough to get my argument rolling. As it goes we represent events locally as a changing series of moments with all of the features mentioned above. The A-theory accounts for it through the passage of time, and the B-theory takes it as simply part of the structure of the Block Universe.

I would think not. If there is a present, it is an absolute state, however undetectable, and other abstract slices of the block are simply misrepresentations of reality. There is no arbitrary choice about it. An arbitrary guess if something preferred suggests itself, and yes, it does.

Doesn't matter. The fact that the Presentist would argue that past and future events aren't real does not change the fact that they do view reality as a series of events. Unless they are temporal solipsists, then they should not disagree with that understanding of time. The only difference between them and the Eternalist is that they would take these series of events to describe a succession of events via. the flow of time, while the Eternalist would view them as locations in the Block Universe.

There's a list of stuff that can vary, and a list that cannot. Yes, the cosmological constant is one, and the hardest one to get to a workable value if you're just pulling random values out of your arse. I guess that implies a lot of bubbles.

But does that list of stuff include the time dimension? I have yet to see a source that says yes.

Try this, which was the first item on my little google of it:
https://www.quora.com/If-there-are-3-physical-space-dimensions-why-arent-there-3-time-dimensions

That isn't what I'm asking for. I wanted a source that says that under the inflationary multiverse, the number of dimensions of time does vary. This link doesn't do that. However it does address the other concern that I had about why we should prefer a 3+1 Universe on anthropic reasons. I am assuming you're referring me to the first answer in the post, which references Tegmark, but if not then please direct me to the appropriate answer.

With regards to that answer, I don't think he actually demonstrates that life cannot work in a universe that does not contain one time dimension. In fact, the author seems to indicate that a world that contains 3 time dimensions and 1 space dimension is possible, albeit very strange, for life. That in itself would rule out the requirement for time to be linear. In addition, in addressing the possibility of multiple time dimensions, the author suggests that the problem with these universes lies in the fact that they are "unpredictable", but it isn't clear to me how that precludes life. Perhaps the argument is going over my head (likely is in a large sense) it apart from the strangeness, I don't see how life cannot work there.

The article I linked gets into this.

For the record, I was objecting to the idea that other combinations of dimensions is somehow incompatible with life, regardless of the sort of universe we these dimensions exist in. I'd imagine if we have sufficient freedom over other factors such as the laws of nature we could potentially build a world that contains multiple dimensions of space and time yet houses life.

Yes, but most of them not macroscopic. We're counting the macroscopic ones here.

Fair enough.

Makes no sense to me. You seem to describe a photo of a dog, which is not a living thing. It isn't life if there are no dynamics.

Not a photo of a dog, but a state of a universe containing a real dog while it's alive. Perhaps one can debate whether or not a single instant is sufficient for life, but I see no reason why it doesn't.

Well, take the relational interpretation then, which has no meaningful state except as measured, and nothing measures the universe (the big bang is a point of view that sees nothing), so the universe has no state, just relations. Everett would say it has solutions to Schrodinger equations. Neither of those has meaningful state. The Bohmian interpretation has it (hard, single-outcome determinism), but it does so at the cost of cause before effect (locality). I personally find the latter more offensive, but that's just my taste.

Not entirely sure if that really solves the problem or makes it worse. At least with respect to the Many-Worlds interpretation of Everett it would appear that the number of states that exist would be multiplied, since they would all be realized together. As for the Bohmian interpretation, I don't think that adopting non-locality would require rejecting causality, provided one introduce a preferred frame to preserve it. In a sense it would make the interpretation quite compatible with Presentism in that regard since it would give us reason to have a notion absolute time again, though I'd imagine that wouldn't make it any more appealing to you.

I am a squishy eternalist. I only take firm stances against positions which don't seem self consistent.

If you're an Eternalist then you think Presentism is wrong. That's what it means to be an Eternalist.

Try this, which was the first item on my little google of it:
https://www.quora.com/If-there-are-3-physical-space-dimensions-why-arent-there-3-time-dimensions

That isn't what I'm asking for, but it does address the other concern that I had about why we should prefer a 3+1 Universe on anthropic reasons. I am assuming you're referring me to the first answer in the post, which references Tegmark, but if not then please direct me to the appropriate answer. — Mr Bee

I didn't even see that there were other answers. Yes, the first one.
I got that myself from Tegmarks book The Mathematical Universe which spends about 80% of its content explaining physics to the layman, and about 20% on the subject in the title. Part of that 80% uses that diagram and has the whole list of things that vary when selecting a tuning, and another list of things that don't.

You can also look at Tegmark's paper referenced at the top of that answer. It is 400 pages and I think only deals with the dimensionality aspect.

I don't think he actually demonstrates that life cannot work in a universe that does not contain one time dimension. In fact, the author seems to indicate that a world that contains 3 time dimensions and 1 space dimensions is possible, albeit very strange, for life.

The 'tachyons only' choice? You can publish that if you can think of a way for tachyons to interact coherently to be structure, let alone one that is a life form. The author Mauro seems to think so, but he omits Tegmarks commentary on that. I think Mauro is mistaking the condition for 3 space and 1 time, but everything moves faster than light, not slower.

Not a photo of a dog, but a state of a universe containing a real dog while it's alive. Perhaps one can debate whether or not a single instant is sufficient for life, but I see no reason why it doesn't.

I think it violates every attempt at a definition of life that I've seen. Perhaps you'd like to give one that would include this timeless configuration of state.

At least with respect to the Many-Worlds interpretation of Everett it would appear that the number of states that exist would be multiplied, since they would all be realized together.

So yes, can be thought of as one collective determined state. I call that soft determinism since the future measurement of some trivial experiment still cannot be predicted even given perfect knowledge of the system and infinite computing capability. It's determinism only because every possible result happens, and that list of results can be (and already is) computable. The relational interpretation is similar, but says the results that were not measured are not real (they didn't happen 'elsewhere'), and is therefore not a deterministic interpretation.

As for the Bohmian interpretation, I don't think that adopting non-locality would require rejecting causality, provided one introduce a preferred frame to preserve it.

No, there are quantum experiments that seemingly effect past measurements by decisions made in the future of those measurements. The before-before experiment is one of them. Only interpretations with locality explain that without reverse causation. A preferred frame helps not at all. The issue is not ambiguous ordering such as spooky action between two events outside each other's light cones. The issue here is blatant cause after effect between events that are within each other's light cones.

If you're an Eternalist then you think Presentism is wrong. That's what it means to be an Eternalist.

Fine. I'm an agnostic then, by the way you use the terms.

You can also look at Tegmark's paper referenced at the top of that answer. It is 400 pages and I think only deals with the dimensionality aspect. — noAxioms

Actually, I had a look at the paper linked and it was just 7 pages long. I think you're mixing up the book with the paper.

I was actually able to follow a good portion of it surprisingly, but unfortunately, I don't consider myself to be capable of engaging with these arguments in a proper manner. Regardless, I still checked the citation list for the article to see what others thought of it (a habit of mine), and I found some objections (here is one of them) to the unpredictability argument that Tegmark promotes in his paper. Not sure what to make of it, but I'd thought I'd throw it out for those who do understand it to look at for themselves.

The 'tachyons only' choice? You can publish that if you can think of a way for tachyons to interact coherently to be structure, let alone one that is a life form. The author Mauro seems to think so, but he omits Tegmarks commentary on that. I think Mauro is mistaking the condition for 3 space and 1 time, but everything moves faster than light, not slower.

I honestly don't know, but I'm just going off of the summary that you gave me. Tachyons, though weird, are not completely impossible from what I can tell but I have no idea how they work to say one way or the other.

I think it violates every attempt at a definition of life that I've seen. Perhaps you'd like to give one that would include this timeless configuration of state.

If one is looking for a more practical definition of "life" then sure I am willing to grant that temporal persistence is necessary. But I wasn't trying to argue with those kinds of definitions.

My concern is with the possibility that we could, as conscious beings, be located on a single static moment of time. Like the situation with Boltzmann Brains and Descartes Demon, I was willing to grant that, given what we currently find in our experience, that we cannot deduce that we are not such beings.

So yes, can be thought of as one collective determined state. I call that soft determinism since the future measurement of some trivial experiment still cannot be predicted even given perfect knowledge of the system and infinite computing capability. It's determinism only because every possible result happens, and that list of results can be (and already is) computable. The relational interpretation is similar, but says the results that were not measured are not real (they didn't happen 'elsewhere'), and is therefore not a deterministic interpretation.

Hmm, the relational interpretation sounds pretty idealistic to me. From what I've read it seems to suggest that there is nothing to the physical world other than our own observation of it. That is, there is no noumenon, no red ball in itself, since there is nothing to it if we are not looking at it. This goes further than the copenhagen interpretation since at least that view allows for the collapse of the wave function.

I don't know what to make of that (especially since I am not qualified to look into it more deeply), but with regards to the topic in the thread, it doesn't seem to undermine the concept of time as we traditionally define it. Physical reality is constituted by the states that are observer dependent, but that doesn't undermine the view that it is a series of states of the same things. And neither does the many-worlds interpretation as far as I see it.

No, there are quantum experiments that seemingly effect past measurements by decisions made in the future of those measurements. The before-before experiment is one of them. Only interpretations with locality explain that without reverse causation. A preferred frame helps not at all. The issue is not ambiguous ordering such as spooky action between two events outside each other's light cones. The issue here is blatant cause after effect between events that are within each other's light cones.

No, I don't think this is correct. Contrary to your claims, it would appear that preferred frames are the only the thing that saves nonlocal interpretations like Bohmian Mechanics from being refuted by the before-before experiment. This paper is very relevant to that.

Regardless, I still checked the citation list for the article to see what others thought of it (a habit of mine), and I found some objections (here is one of them) to the unpredictability argument that Tegmark promotes in his paper. Not sure what to make of it, but I'd thought I'd throw it out for people for those who do understand it to look at for themselves. — Mr Bee

A good habit to hunt down critique. Helps point out which parts on which focus should be placed. I do it myself for papers whether or not I agree with them. I'll try to look at that link closer, but a good deal of it is beyond me.

Tachyons, though weird, are not completely impossible from what I can tell but I have no idea how they work to say one way or the other.

I was actually more concerned with 1D life form, let alone one comprised of only stuff that can't go slow. But who am I to say that just because it is incomprehensibly different that coherent structures cannot form in it. 3D of time, whatever that means, is plenty of room for complexity. But I don't even follow the argument that only tachyons result.

If one is looking for a more practical definition of "life" then sure I am willing to grant that temporal persistence is necessary. But I wasn't trying to argue with those kinds of definitions.

I was thinking dynamics more than persistence. I cannot think of a single thing distinguishing life from non-life that doesn't involve dynamics (a reference to time).

My concern is with the possibility that we could, as conscious beings, be located on a single static moment of time.

That, if it were a being, would not be conscious. Yes, I had thought of Boltzmann brains when this was brought up, but even those have momentary dynamics. A Boltzmann brain is not a life form, even if it technically qualifies as conscious for a very brief duration.

Hmm, the relational interpretation sounds pretty idealistic to me. From what I've read it seems to suggest that there is nothing to the physical world other than our own observation of it.

Idealism has to do with relations to consciousness. The relational view, being non-anthropocentric, is relative to anything at all. A rock does fine, co-existing with the things with which it interacts. Hence no contradiction about how we came about before we gave existence to what was before us.

The only nearly anthropocentric QM interpretation I can find seems to be the Wigner one, which posits consciousness, but not necessarily human consciousness causing wave function collapse.

That is, there is no noumenon, no red ball in itself, since there is nothing to it if we are not looking at it.

Except for the 'we' part, yes. Look up the principle of counterfactual definiteness. It says that the red ball exists even unmeasured. More formally worded, "counterfactual definiteness (CFD) is the ability to speak "meaningfully" of the definiteness of the results of measurements that have not been performed (i.e., the ability to assume the existence of objects, and properties of objects, even when they have not been measured)". That's straight off the wiki page, my bold.

This goes further than the copenhagen interpretation since at least that view allows for the collapse of the wave function.

Relation interpretation has collapse. Collapse is what makes the red ball real. MWI does not have collapse.

I don't know what to make of that (especially since I am qualified to look into it more deeply), but with regards to the topic in the thread, it doesn't seem to undermine the concept of time as we traditionally define it.

It relates to the state of the universe in the block, but also in the flowing view. You're right, it doesn't really come into play until you start bringing up determinism, which can be asserted one way or the other with either view of time.

No, I don't think this is correct. Contrary to your claims, it would appear that preferred frames are the only the thing that saves nonlocal interpretations like Bohmian Mechanics from being refuted by the before-before experiment. This paper is very relevant to that.

Bohmian mechanics is not refuted by any experiment. I never claimed that. It just denies locality, and so allows effect before cause, as does any interpretation that denies locality. That makes the interpretaion invalid only if you assert otherwise.

A good habit to hunt down critique. Helps point out which parts on which focus should be placed. I do it myself for papers whether or not I agree with them. I'll try to look at that link closer, but a good deal of it is beyond me. — noAxioms

No worries. I won't be able to fully engage with it anyways at least until I get a proper education on these matters so we're mostly in the same boat here.

Idealism has to do with relations to consciousness. The relational view, being non-anthropocentric, is relative to anything at all.

I never said it was idealistic, just that it has a very idealistic tone to it since it makes everything observer dependent. I suppose the same problems I have with it are similar to that of the copenhagen interpretation. You know that quote about the moon not being there where you're not looking at it? That's what first came to my mind.

Relation interpretation has collapse. Collapse is what makes the red ball real. MWI does not have collapse.

So it is. What I wanted to say was that I thought the copenhagen interpretation allowed for some observer independent states after collapse, unlike the relational interpretation, but that may not be correct.

Bohmian mechanics is not refuted by any experiment. I never claimed that. It just denies locality, and so allows effect before cause, as does any interpretation that denies locality. That makes the interpretaion invalid only if you assert otherwise.

And if you look at the paper I linked the author seems to suggest otherwise. He brings up the problems with the preferred frame view (it's empirical unobservability, the free will problem), but he does not mention the lack of a time order which he considers to refute the other non-local views.

I never said it was idealistic, just that it has a very idealistic tone to it since it makes everything observer dependent. I suppose the same problems I have with it are similar to that of the copenhagen interpretation. — Mr Bee

Neither of those interpretations require the observer to be a living thing. As I said, a rock will do.

You know that quote about the moon not being there where you're not looking at it? That's what first came to my mind.

It wouldn't be there if you had never looked at it, but it cannot be un-looked at. If you completely stop interacting with it (impossible), it would drop into a superposition of damn-likley existing, but possibly not. It's the moon. It isn't going anywhere. Both relational and copenhagen say this. Even if the moon by chance spontaneously decays into nonexistence, surely that would leave behind some energy wad that would still be the moon.

So it is. What I wanted to say was that I thought the copenhagen interpretation allowed for some observer independent states after collapse, unlike the relational interpretation, but that may not be correct.

Well, after collapse, no state is totally observer independent. Example would be nice I guess so I might comment on the different interpretations. We're getting kind of off-topic here.

And if you look at the paper I linked the author seems to suggest otherwise.

Cannot read it. It downloads a pdf with an unreadable font.

He brings up the problems with the preferred frame view (it's empirical unobservability, the free will problem), but he does not mention the lack of a time order which he considers to refute the other non-local views.

I'd have to look to see what you mean by that. Maybe you can find a more readable version.

Cannot read it. It downloads a pdf with an unreadable font. — noAxioms

It should be viewable without download in the link provided. Just scroll down.

Neither of those interpretations require the observer to be a living thing. As I said, a rock will do.

I wasn't disputing that. I understand that the definition of an "observer" needn't refer to a guy in a lab coat.

We're getting kind of off-topic here.

Agreed that the issue appears to be irrelevant to the OP. Just giving my own side thoughts about the relational interpretation since it was brought up and all.

It should be viewable without download in the link provided. Just scroll down. — Mr Bee

Both chrome and IE show no page, just the download.

Just giving my own side thoughts about the relational interpretation since it was brought up and all.

OK, but your thoughts were only that it doesn't have collapse. It does.

I might say I support this interpretation, but you'd then say that means I find the other interpretations wrong, and I don't. So I am again agnostic by the way you explain above. To deny other interpretations is to deny that they are inconsistent with themselves. That they are inconsistent with my preferences is evidence of nothing if I have no empirical evidence that my preferences are correct.

Both chrome and IE show no page, just the download. — noAxioms

Okay, here's a separate link from another site. For the record, I'm using chrome so best start there.

OK, but your thoughts were only that it doesn't have collapse. It does. — noAxioms

Um, no. My thoughts were mainly that I thought it sounded idealistic (again not saying it is idealism). The idea that it didn't contain collapse was an incorrect assumption on my part. But like you said earlier, this is all irrelevant.

I might say I support this interpretation, but you'd then say that means I find the other interpretations wrong, and I don't. So I am again agnostic by the way you explain above. To deny other interpretations is to deny that they are inconsistent with themselves. That they are inconsistent with my preferences is evidence of nothing if I have no empirical evidence that my preferences are correct. — noAxioms

It depends on what you mean by "support" then. If by the term you meant that you find that interpretation more useful as a practical tool for understanding QM, then that's one thing. Some physicists may find the block universe model helpful as a tool to do relativity, but that is not really taking a metaphysical stance. Similarly, I don't find my oven "wrong" just because I prefer to microwave my food. They are just alternative tools to do the same job.

However, if you mean that you believe in one interpretation being true, then if that interpretation is logically incompatible (as in mutually exclusive) with another interpretation, then you believe that other interpretation to be wrong. If I believe that object over there is a square, then that means that I think it isn't a circle. It is just a matter of basic logic so you simply can't have it both ways, but if you disagree with this for whatever reason, then I'm not gonna push it.

Contrary to your claims, it would appear that preferred frames are the only the thing that saves nonlocal interpretations like Bohmian Mechanics from being refuted by the before-before experiment. This paper is very relevant to that. — Mr Bee

I got to the paper finally with the new link you provided. The term Leggett-like model is new to me. I don't see a description of before/before. I see it named, but not described. It interestingly defines a 'realism' as theories where 'results of observations are a consequence of pre-existing properties', i.e. cause before effect.

The article then goes on to describe relationships between measurements done by Alice and Bob respectively in space-like separated events, that only a preferred frame keeps the non-local influence time ordered.

Unfortunately, the before-before experiment (which I didn't see described) very much violates time-ordering since the effect measurement events by Alice and Bob are separated from the cause decision event by Victor in a time-like separation, not a space-like separation, and thus any proposed non-local influence is necessarily not going to be time ordered.

I'm not sure how Bohmian mechanics describes the before-before experiment. I thought it explained spooky-action through hidden variables, not through time ordered non-local influence, but I don't see how hidden variables can explain before-before.

It depends on what you mean by "support" then. If by the term you meant that you find that interpretation more useful as a practical tool for understanding QM, then that's one thing. — Mr Bee

QM is science, and not aided much at all with any interpretation. That is why a QM class will perhaps touch on the various interpretations, but not promote or dwell on one since none of them are QM. The "shut up and calculate" refers to this. Shut up about the interpretations, and calculate what QM theory actually says, because it made most amazingly accurate predictions right from the beginning. Interpretations are philosophy, and the QM class is not teaching philosophy.
I on the other hand am more interested in the philosophical implications of QM, so I don't shut up, and I have opinions, but recognize that my opinions are only that, and that different opinions are not wrong just because the differ with mine. Being an X-ist is not a denial of Y-ism.

However, if you mean that you believe in one interpretation being true, then if that interpretation is logically incompatible (as in mutually exclusive) with another interpretation, then you believe that other interpretation to be wrong.

Agree, so I think that when I say I'm an X-ist, it isn't a statement so strong as to say I assert it is true. Lacking any evidence, it would be a very poor thing to assert. So it remains a mere preference. If there was a way to actually know in the future, I would place my bets on certain views over others, and I suspect as probably many of us do that I would fare better than most in the horses I choose to back.
And I am also aware that there are horses that nobody has even suggested. Nobody would ever have suggested something as unintuitive as MWI before QM experiments forced the hand into a series of mutually unintuitive choices. The horses everybody chose back then were all proven wrong, but one of them still probably beat the others, even if they didn't win the race. So I'm more betting on my horses beating the other guy's horses, and not so much on them actually winning the race.
This is a pretty arrogant statement as I back some fairly unpopular horses.

MWI is effectively a special case of the Relational interpretation, as related only to the universe as a whole, or more specifically the big bang singularity event, so in a way, a subset of it. The only difference between the two would be that MWI would say the universal wave function is real, and Relational would say it is real in relation to the universe.

BTW, none of this directly relates to presentism, or A-theory as you call it. A preferred frame is not a preferred moment, even if a preferred moment seems to require a preferred foliation if not a frame. I know of no interpretation of QM or of relativity that asserts (or explicity denies) a preferred moment, although the presentist crowd does seem to congregate around absolute frame notational interpretations like Lorentz-ether-Theory, despite it not proposing a preferred moment in time.

I don't see a description of before/before. I see it named, but not described. — noAxioms

Not sure why you feel the need to say that. If you're concerned about whether the author understands the before-before experiment or is knowledgeable of it, than he is one of the two people who proposed the very idea in the first place and one of the main authors of papers about the experiment from what I can see.

Unfortunately, the before-before experiment (which I didn't see described) very much violates time-ordering since the effect measurement events by Alice and Bob are separated from the cause decision event by Victor in a time-like separation, not a space-like separation.

The article very explicitly addresses the before-before experiment and clearly states that preferred frame models such as that of Bohmian mechanics do not violate time-ordering. You're free to disagree with that but that is what the article states.

I'm not sure how Bohmian mechanics describes the before-before experiment. I thought it explained spooky-action through hidden variables, not through time ordered non-local influence, but I don't see how hidden variables can explain before-before.

It's both. Bohmian Mechanics is a deterministic non-local hidden variable interpretation.

BTW, none of this directly relates to presentism, or A-theory as you call it.

Presentism is not equal to the A-theory. It is a subset of it. What the argument in the OP tries to support are the set of views that include a passage of time, Presentism being one of them.

A preferred frame is not a preferred moment, even if a preferred moment seems to require a preferred foliation if not a frame.

A preferred frame/foliation allows us to define an absolute order of events, and in turn the preferred moment. The reason why Relativity undermines the idea of a preferred moment is because it states that there is no way to choose one frame or foliation of events, and that therefore there isn't any preferred frame/foliation. Without it, we would not be able to make sense of the passage of time, as least that is how it is commonly viewed. Now there appear to be some who dispute this, who claim that a concept of becoming can exist without a global now but for the most part I am just going off of the traditional opinion on the matter.

The article very explicitly addresses the before-before experiment and clearly states that preferred frame models such as that of Bohmian mechanics do not violate time-ordering. You're free to disagree with that but that is what the article states. — Mr Bee

No frame, preferred or otherwise puts cause before effect in the Bohmian interpretation of before-before results. So I guess I don't understand where the article addresses that. The two events are separated time-like, so there is no ambiguity to their ordering that can be disambiguated with a preferred frame.

Presentism is not equal to the A-theory.

From what I read, A-theory includes growing block and presentism, which differ in the ontological status of past events, but both posit the flow of a preferred moment, so all my comments about presentism so far also can be applied to growing block. Perhaps you can explain the distinction if it is more than that.

I'm saying that no QM or relativistic interpretation seems to propose flowing time. I'm probably wrong, but I'm just unaware of one. Some assert a preferred frame, but that isn't flow.

A preferred frame/foliation allows us to define an absolute order of events, and in turn the preferred moment.[/quote]First of all, no inertial frame foliates all events, so it would have to be some non-inertial foliation like the obvious comoving one. Yes, it allows (seems necessary for) the preferred moment, but does not need one.

The reason why Relativity undermines the idea of a preferred moment is because it states that there is no way to choose one frame or foliation of events, and that therefore there isn't any preferred frame/foliation.

Relativity just says it isn't locally detectable. Non-locally, one does suggest itself, and GR very much acknowledges it. It is the foliation where spatial expansion is symmetric/isomorphic.

Now there appear to be some who dispute this, who claim that a concept of becoming can exist without a global now but for the most part I am just going off of the traditional opinion on the matter.

The concept of becoming seems required only for the flowing model, but doesn't fit well at all with the block model. That's a good deal of the appeal of the block model is it doesn't need to explain the becoming.

No frame, preferred or otherwise puts cause before effect in the Bohmian interpretation of before-before results. So I guess I don't understand where the article addresses that. The two events are separated time-like, so there is no ambiguity to their ordering that can be disambiguated with a preferred frame. — noAxioms

This just sounds like a bald assertion on my end. The issue of a preferred frame model is clearly addressed in the section that is titled as such. Again, the author refers to the preferred frame model of Bohmian Mechanics explicitly as one that is time ordered, and admits that it's empirical predictions are compatible with the correlations found in the before-before experiment. Take no offense, but at this point, I am more willing to side with his view over yours.

From what I read, A-theory includes growing block and presentism, which differ in the ontological status of past events, but both posit the flow of a preferred moment, so all my comments about presentism so far also can be applied to growing block. Perhaps you can explain the distinction if it is more than that.

There's also the moving spotlight view of time as well, which says that all events in the universe's history exist but that there is a dynamic spotlight that shines on the set of events that represents the present. This is what I have told you at my first reply.

I'm saying that no QM or relativistic interpretation seems to propose flowing time. I'm probably wrong, but I'm just unaware of one. Some assert a preferred frame, but that isn't flow.

No interpretation says anything about the existence of the block universe either. None of them have any direct say on the matters of the metaphysics of time. The only thing that I can say is that, in including a preferred frame, some interpretations are more compatible with the idea of a flow of time than others.

Relativity just says it isn't locally detectable. Non-locally, one does suggest itself, and GR very much acknowledges it. It is the foliation where spatial expansion is symmetric/isomorphic.

Yeah, the direct implication of Relativity's postulates is that if there were such a preferred frame, it would not be empirically detectable, which some have taken to be evidence of it's nonexistence. The CMB is taken by some to be a preferred foliation of the universe in a sense, but it is debatable whether it is good enough for the A-theorist's purposes.

The concept of becoming seems required only for the flowing model, but doesn't fit well at all with the block model. That's a good deal of the appeal of the block model is it doesn't need to explain the becoming.

I would actually argue that, in rejecting the idea of becoming, the block model has more trouble accounting for why the universe appears to become in time (given its structure), and that this is a weakness of the view relative to its alternative. This is the argument that I have been trying to push here in this thread.

Again, the author refers to the preferred frame model of Bohmian Mechanics explicitly as one that is time ordered, and admits that it's empirical predictions are compatible with the correlations found in the before-before experiment. Take no offense, but at this point, I am more willing to side with his view over yours. — Mr Bee

A model is considered time ordered when it proposes that a cause event tomorrow can effect a measurement taken yesterday in the same place? Perhaps I don't know what 'time ordered' means, as used in that article. The one picture in there showed non-local influence arrow in a spooky-action setup, and without a preferred frame, the direction of the arrow would be ambiguous. So maybe that's what they mean by time-ordered: Not that the arrow always points forward, just that it doesn't point either way. In the before-before, it doesn't point in an ambiguous direction. It is consistently pointing backwards.

There's also the moving spotlight view of time as well, which says that all events in the universe's history exist but that there is a dynamic spotlight that shines on the set of events that represents the present. This is what I have told you at my first reply.

Well, to be thorough then, there might also be the one where only present and future exists, but the past, being no longer useful, fades away. I think the Langoliers movie depicted something like this.
The spotlight people definitely need two kinds of time, else how did the future come to be if it hasn't happened yet? How long ago was it created? How far did that part get before the spotlight started? Strange questions like that...
For that matter, I don't understand what possible problem is solved by growing block as opposed to presentism. I looked up the wiki page, and it defined it, but went no further in pointing out a single benefit of it.

No interpretation says anything about the existence of the block universe either. None of them have any direct say on the matters of the metaphysics of time.

The Minkowski model is one specifically of a block scenario. It is a straight metaphysical interpretation of time, making no empirical predictions distinct from the flowing model. Einstein drew on the mathematics of this model and Lorentz's work in producing his theory of relativity. But yes, the theory of relativity does not itself assert those metaphysics. It just uses the mathematics of spacetime, and refers regularly to spacetime as a unified whole.

Yeah, the direct implication of Relativity's postulates is that if there were such a preferred frame, it would not be empirically detectable, which some have taken to be evidence of it's nonexistence.

Only SR says it is undetectable. GR does not, since it isn't just a local theory. There are non-local tests for an isomorphic foliation, which isn't an inertial frame, but seems to be the most viable candidate for some kind of preferred ordering of all events anywhere.

The CMB is taken by some to be a preferred foliation of the universe in a sense,

Careful with your wording. The CMB is not a foliation and, being light, is certainly not stationary relative to any frame, but a foliation is suggested by combining the local frames in which the CMB appears to be isomorphic. Hence my calling it the isomorphic foliation.

but it is debatable whether it is good enough for the A-theorist's purposes.

Really?? Do any of them suggest another, like the frame of the solar system perhaps? That would suit the purpose of some people that would seem to have a requirement for A-theory.

The concept of becoming seems required only for the flowing model, but doesn't fit well at all with the block model. That's a good deal of the appeal of the block model is it doesn't need to explain the becoming.

I would actually argue that, in rejecting the idea of becoming, the block model has more trouble accounting for why the universe appears to become in time (given its structure), and that this is a weakness of the view relative to its alternative.

It does? I wasn't there at the time. Couldn't say. Yes, the A-theorists might say that, but doing so begs a different view. I find becoming to be difficult to explain, with all the uncaused-cause contradictions.
The block guy, if he posits that the block IS, needs to explain how it is, but not how it came to be. A different question, but still not an easy one. Platonic realism sometimes is invoked. My relational preference doesn't presume that anything IS, just that it relates to something, so I need to posit what the universe stands in relation to.

A model is considered time ordered when it proposes that a cause event tomorrow can effect a measurement taken yesterday in the same place? Perhaps I don't know what 'time ordered' means, as used in that article. The one picture in there showed non-local influence arrow in a spooky-action setup, and without a preferred frame, the direction of the arrow would be ambiguous. So maybe that's what they mean by time-ordered: Not that the arrow always points forward, just that it doesn't point either way. In the before-before, it doesn't point in an ambiguous direction. It is consistently pointing backwards. — noAxioms

I feel like you're being obtuse at this point. I see no ambiguity in the use of "time-ordered". It means that causes always precede their effects in time. The author has been pretty clear in referring to time-order in that sense. Here are a few examples:

Section 2 considers time-ordered Leggett models assuming thatone event can be considered the cause (occurring before in time), and the other the effect (occurring later in time). — Antoine Suarez

“Nonlocal realism” (as defined in [1, 5]) fails if experiment proves wrong that one of two non-locally correlated events occurs before and is the cause of the other.

Models assuming that the “realistic” mechanism happens in a single preferred frame even in relativistic experiments with devices in motion, are not refuted by the before-before experiment, but such models bear a fundamental oddity: since they assume that each event has a cause preceding it in time, they actually dispose of the freedom of the experimenter.

My emphasis on all except for the second. The last is more relevant to the discussion than the others. The reason why, to my understanding, that the experiment does not undermine causality is because models such as that of the Bohm interpretation restrict the freedom of the experimenters. The experiment is already predetermined, which is to be expected of a deterministic theory.

Thus, if one wishes to save time-ordered causality one is forced to assume that the outcomes are determined at the beam splitters (like De Broglie and Bohm did). — Antoine Suarez

Any "retrocausality" observed would only be apparent.

Only SR says it is undetectable. GR does not, since it isn't just a local theory. There are non-local tests for an isomorphic foliation, which isn't an inertial frame, but seems to be the most viable candidate for some kind of preferred ordering of all events anywhere. — noAxioms

As far as I can tell, the CMB frame is not a physically distinguished frame in the sense that a preferred frame in SR is physically distinguished (as in the laws of physics are observed to be different in that frame). In that sense, so much as it is preferred, such a fact would be undetectable.

For that matter, I don't understand what possible problem is solved by growing block as opposed to presentism. I looked up the wiki page, and it defined it, but went no further in pointing out a single benefit of it. —

It solves the problem of truthmakers for the past. In saying that the past exists and is real, the Growing Block Theorist has the resources to talk about it unlike the Presentist. Personally I think the truthmaker argument begs the question against Presentism in assuming that truthmakers all must currently exist, but I won't go into that here.

The Minkowski model is one specifically of a block scenario. It is a straight metaphysical interpretation of time, making no empirical predictions distinct from the flowing model. Einstein drew on the mathematics of this model and Lorentz's work in producing his theory of relativity. But yes, the theory of relativity does not itself assert those metaphysics. It just uses the mathematics of spacetime, and refers regularly to spacetime as a unified whole.

Sorry, I thought you were just referring to QM interpretations, and missed the "relativistic". In that case, the alternative interpretations to the Minkowski Spacetime such as the Neo-Lorentz interpretation of SR do include a flow of time as it is supposed to preserve the traditional view of time as a dynamic succession of events in a 3D universe. Such an evolution refers to what people often understand as becoming.

Really?? Do any of them suggest another, like the frame of the solar system perhaps? That would suit the purpose of some people that would seem to have a requirement for A-theory.

It's not really the A-theorists who are making that claim, but the B-theorists who are objecting to the CMB as a means of defining a preferred moment because it appears to be arbitrary to do so. According to them there is no clear link between the CMB and the preferred moment in metaphysics that should lead us to equate one with the other. In a sense, I can see where they're coming from since, as noted above, the CMB is not physically distinguished like we would want it to be. In that regard, we have just as much reason to prefer it over any other alternative foliation of events.

Of course, if the CMB were to be physically distinguished and people are making the same objections then that'd be another story altogether, for one could very well have made such an objection prior to relativity in the 1800s with respect to the absolute time of Newtonian physics. At that point it would be unreasonable to require that there needs to be a neon light sign that says "This is a preferred moment of metaphysics" over the preferred moment picked out by physics in order to say that they are both equivalent.

It does? I wasn't there at the time. Couldn't say.

I have no idea what this is supposed to mean. The entire thread is based around that specific argument.

I find becoming to be difficult to explain, with all the uncaused-cause contradictions.

This is confusing to me. Becoming conceptually requires no uncaused causation, and even I see nothing contradictory about an uncaused cause.

I feel like you're being obtuse at this point. I see no ambiguity in the use of "time-ordered". It means that causes always precede their effects in time. The author has been pretty clear in referring to time-order in that sense. — Mr Bee

That's why I wonder about before-before, which blatantly puts cause well after effect, and in any reference frame. Or at least it does in non-local interpretations.

they assume that each event has a cause preceding it in time, they actually dispose of the freedom of the experimenter

This seems to explain it. If measurements are taken yesterday, and Victor's decision as to how those measurements correlate not yet made, apparently the interpretation is that the results of the measurements cause Victor to decide to correlate them, despite complete separation (no causal path) from measurements made by Alice and Bob to Victor making his decision.

It apparently satisfies time-orderedness by switching labels of cause and effect.

As far as I can tell, the CMB frame is not a physically distinguished frame in the sense that a preferred frame in SR is physically distinguished (as in the laws of physics are observed to be different in that frame). In that sense, so much as it is preferred, such a fact would be undetectable.

Agree

It solves the problem of truthmakers for the past. In saying that the past exists and is real, the Growing Block Theorist has the resources to talk about it unlike the Presentist.

OK, that makes some sense. If the past is gone, is "Einstein existed" a true statement? Being a past tense, I don't see why not. It definitely changes the truth value of "Einstein exists".

Sorry, I thought you were just referring to QM interpretations

No, none of those seem to depend on any particular interpretation of time. I might be wrong about that.

In that case, the alternative interpretations to the Minkowski Spacetime such as the Neo-Lorentz interpretation of SR do include a flow of time as it is supposed to preserve the traditional view of time as a dynamic succession of events in a 3D universe.

It has that. Is this something different than Lorentz Ether Theory, because I found no mention of flow in any description of it. Maybe Neo-Lorentz adds that on top of LET. Lorentz himself seemed not to see things that way, especially since he set a lot of the groundwork for Minkowski's model.
Lorentz's model is older than knowledge of the expanding universe, so I wonder how he posited his preferred frame or foliation.

It's not really the A-theorists who are making that claim, but the B-theorists who are objecting to the CMB as a means of defining a preferred moment because it appears to be arbitrary to do so.

How could CMB possibly suggest a preferred moment??? A preferred frame, sure, but not preferred moment. The A-Theorists similarly do not base their definition of the preferred moment on the CMB. Their moment is simply 'now'. Easy-peasy.

According to them there is no clear link between the CMB and the preferred moment in metaphysics that should lead us to equate one with the other. In a sense, I can see where they're coming from, as noted above, the CMB is not physically distinguished like we would want it to be. In that regard, we have just as much reason to prefer it over any other alternative foliation of events.

Of course, if the CMB were to be physically distinguished and people are making the same objections then that'd be another story altogether, for one could very well have made such an argument prior to relativity in the 1800s with respect to the absolute time of Newtonian physics. At that point it would be unreasonable to require that there needs to be a neon light sign that says "This is a preferred moment of metaphysics" over the preferred moment picked out by physics in order to say that they are both equivalent.

I do not understand these paragraphs. I think you meant to say preferred frame.
What is 'physically distinguished'?

This is confusing to me. Becoming conceptually requires no uncaused causation, and even I see nothing contradictory about an uncaused cause.

Maybe I don't understand this notion of becoming. It's not a term I use regularly.
All causes seem to be effects of prior causes, but barring an infinite past, there must be a first cause, uncaused. Surely you've heard of that. Block theory has one, but it is just a (perhaps blank) initial condition. Not sure how becoming is expected to fit into that.

That's why I wonder about before-before, which blatantly puts cause well after effect, and in any reference frame. Or at least it does in non-local interpretations. — noAxioms

Again, the paper suggests otherwise. Given that my expertise on the matter is not that deep, that your knowledge level on the issue appears to be similar to mine, and the fact that the source that I have referenced appears to know much more about the before-before experiment then either you and me, I can only take his word on the matter that the before-before experiment does not violate causality under non-local interpretations, contrary to your own claims..

The thing about the before-before experiment is that there isn't that much literature on it. The only person who seems to be writing about it extensively is the author of the source that I have referenced, Antoine Suarez. At least this is what I've gotten from google searches into the matter.

I assume that you would probably make the same statements about causality violation for other attempts at proving retrocausality in QM. The delayed choice quantum eraser comes to mind here. With respect to experiments like those, I can certainly say that the apparent retrocausal effects found in those experiments are merely that and that different interpretations, including that of Bohmian Mechanics, can accomodate it without giving up causality. There is alot more literature on the matter that would demonstrate that.

It has that. Is this something different than Lorentz Ether Theory, because I found no mention of flow in any description of it. Maybe Neo-Lorentz adds that on top of LET.

LET and the Neo-Lorentzian Interpretation are one and the same. In other words, LET was simply the scientific theory of SR with the Neo-Lorentzian Interpretation. I don't know if there is any explicit mention of the flow of time in it's description, but it would be hard to deny that it included one given that it preserves the traditional view of absolute time.

How could CMB possibly suggest a preferred moment??? A preferred frame, sure, but not preferred moment. The A-Theorists similarly do not base their definition of the preferred moment on the CMB. Their moment is simply 'now'. Easy-peasy.

So do you think that the preferred moment should be equated with the set of moments picked out by the CMB? It seems like one moment you think that it should (like in your previous response to me), then the next you think it shouldn't (like you are here).

I do not understand these paragraphs. I think you meant to say preferred frame. What is 'physically distinguished'?

We've just gone over how the CMB frame was not physically distinguished in the sense given by the postulates of relativity.

Since there is no difference between the CMB frame and any other in that sense, then that should give us reason to not take the former to represent the preferred moment that the A-theorists want. At least, this is part of the reason why I feel hesitant to call the CMB frame anything more than one that has some interesting properties.

It would be a different matter if that wasn't the case though. If the laws of physics do single out a particular foliation of events then it seems to be more of a stretch to deny that the present moment picked out by such a foliation is not the same as that of the metaphysical present, at least in my opinion.

All causes seem to be effects of prior causes, but barring an infinite past, there must be a first cause, uncaused. Surely you've heard of that. Block theory has one, but it is just a (perhaps blank) initial condition. Not sure how becoming is expected to fit into that.

I suppose I don't find anything wrong with an infinite past, or infinities in general really, but I don't want to argue that here. There's also the possibility of cyclical time as well, if one doesn't want a first cause or an infinite past.

The block universe, as I understand it, is compatible with a first cause or none at all. It doesn't necessarily have one or none.

So do you think that the preferred moment should be equated with the set of moments picked out by the CMB? It seems like one moment you think that it should (like in your previous response to me), then the next you think it shouldn't (like you are here). — Mr Bee

I am totally in the dark as to how the CMB would pick out a specific moment.

Since there is no difference between the CMB frame and any other in that sense, then that should give us reason to not take the former to represent the preferred moment that the A-theorists want.

How does a selection of a frame suggest there being a special moment in it? The block model has a objective frame, independently discoverable by observers elsewhere, but no preferred moment is similarly discoverable by other observers.

At least, this is part of the reason why I feel hesitant to call the CMB frame anything more than one that has some interesting properties.

Yes, that's why I called it an objective foliation, not necessarily a preferred one. By objective, I just mean it can be independently discovered by any observer anywhere. I don't mean a foliation that orders events in actual order. That would perhaps be that preferred frame.

It would be a different matter if that wasn't the case though. If the laws of physics do single out a particular foliation of events then it seems to be more of a stretch to deny that the present moment picked out by such a foliation is not the same as that of the metaphysical present, at least in my opinion.

I don't see how any foliation picks out any particular moment. It is a thing you've arbitrarily decided to add.

I suppose I don't find anything wrong with an infinite past, or infinities in general really, but I don't want to argue that here. There's also the possibility of cyclical time as well, if one doesn't want a first cause or an infinite past

Mathematically, I have little problem with either. Have to explain entropy though.