Time flows but not "in any particular direction"? — Luke

Flow is a word we use to describe what happens to water in rivers, i.e. for things moving in one direction. In eternalism there is no present moment, and past and future exist just the same. You can go equality forward or backwards in time, it doesn't matter, there is no direction of time... so the word flow doesn't apply. But that doesn't mean that there are no different moments in time, and so things can move just like they can in other theories of time. Movement is just a function of change in position over time, directionality doesn't matter for movement.

That's not what the B-theory is. This would imply that time flows when "viewed from the inside", but then it would be no different to the A-theory. — Luke

Again past and future existing and a direction to time is different... But ok fine, if you want to talk about theories that clearly don't apply to the world I or everybody else experiences, be my guess, but I have nothing to say about that.

I'll try the explain.

This is the first description I've found of B-theory on wiki and I think it better than the others because it uses 'flow' of time rather than 'passage' of time :

"B-theorists argue that the flow of time is an illusion, that the past, present, and future are equally real, and that time is tenseless."

I think it's not so much that time doesn't pass in the sense that there are different moments of time, but that it doesn't flow in any particular direction. The other difference is that all moments of time have the same ontological status, they are equally real if you want.

Maybe it's easier to understand with a graph :



In A-theories what exist is only everything in the 3 spacial dimensions (represented by 2 in the picture), and those move through the 4th dimension in one direction.

In B-theories all everything in all 4-dimensions exists (respresented by a 3d-block in the picture). But the time dimension is still there.

If one says the block-universe is static or unchanging, one is looking at the whole picture, all the 4-dimensions, and says the 'line' or 'worm' in the eternalist graph as a whole doesn't change (thereby imagining another 5th dimension where that change would have to take place, i.e. 'viewed from the outside').

Movement or change is just the same as in the presentist picture, it is represented in the eternalist picture by the line bending in the space-dimensions at different moments in time. If we were to fastforward time in the presentist picture, and place a dot in it representing an object, you would get the same bended line or worm as you fastforward.

So to re-iterate, there is no difference with regards to movement and moments of time (time passing), only what exists and the direction of time (flow) is different.

And for both, looking at it from the outside of the time-dimenision, would be the wrong way of looking at it in respect to movement. It's just that we are more tempted to look at the block-universe from the outside because all times exist and we picture an entire block allready... but it would be just as bad a move for presentism.

There is no movement within that 4d object because there is no passage of time. — Metaphysician Undercover

So I've been told, over and over again, but I don't see why there is something fundamentally different about something existing at time t1, t2, etc ... and time passing (aside from the direction and the ontology which I already agreed with). The moments of times associated with past, future and present all exist in eternalism, but not at the same time, right? That's what the 4th dimension indicates.

Maybe I don't understand because I'm not a metaphysician and I think words are merely trying to describe things and are never the things themselves... but who knows?

See, you're on the right track here. Now, do you see how your statement above, "movement happens within the object because the time-dimension is already included in its existence", is inconsistent with this? You cannot say that "movement" happens within the object, because it's a word classed with those others, "unchanging", and "static", which assumes something outside the four dimensions. — Metaphysician Undercover

No it precisely doesn't assume something outside the four dimensions, that's the whole point, that one should adjust the concept of movement to the 4d frame. If I were to say a 4d object moves as a whole then I would be assuming some other additional dimension, but I'm not doing that, that's what I'm criticizing.

Again I'm not a metaphysician and I don't assume words to have fixed meanings... but if you want to insist that the word movement doesn't apply, fine, then i'll have to invent another word with basically the same meaning for things changing position over time.

Eternalism...is sometimes referred to as the "block time" or "block universe" theory due to its description of space-time as an unchanging four-dimensional "block", as opposed to the view of the world as a three-dimensional space modulated by the passage of time. — Eternalism (philosophy of time) - Wikipedia

According to The B Theory...there is no sense in which it is true to say that time really passes, and any appearance to the contrary is merely a result of the way we humans happen to perceive the world. — SEP article on Time

Okay, maybe that is how some view the block-universe, I can't speak to how they view it of course. But still, I think using words like 'unchanging' or 'static' to describe the block-universe is misleading because it assumes a perspective from outside the 4 dimensions.

It seems as though we are at an impasse — Luke

Yes I agree, but that's ok... the discussion has certainly helped my understanding of the issues involved.

And the way it has played out so far, it seems to be predominately about race, which I don't disagree is a part of it, but it does risk missing the other aspect, especially in the measures that will be taken ultimately.
— ChatteringMonkey

But then the point would be to encourage a more expansive and robust notion of race than to rail against its very mention. Now's the time to do it, if any. — StreetlightX

Yes, maybe that is a valuable endeavor in itself... but don't you think the nuance will be lost on most, short attentions spans and all that? Or is that to cynical?

if you exist as a static four-dimensional object — Luke

This is what I'm objecting to. There is nothing static about a four-dimensional object, it's dynamics by virtue of it existing in a 'four'-dimensional space-'time'. It can only be considered static when viewed from outside the time-dimension of 4d space-time, in relation to some other imaginary fifth time-dimension.

Or put in another way, you cannot simply treat a 4d object the same as a 3d object, in the sense that the entire 4d object has to move in time, like a 3d object does. The movement happens within the object because the time-dimension is already included in its existence.

If we assume that time does not pass and that motion is not real, — Luke

And I think this assumption is not a good way to go about categorizing theories of time, because for this category it is already assumed that it cannot work. Why have a category for something that is impossible? I think, rather, we should only be looking at theories of time that could possibly fit our experience. Eternalist claim that the theory could fit our experience, I'm not entirely sure yet, but that is not because I think motion or passage of time are impossible under it... or assumed to be impossible even.

No one is arguing - or at least I'm not arguing - that these issues are 'purely' race issues. If anything my line of argument has been the exact opposite: that race issues cannot be understood without implicating them into economic, social, and historical ones. But this recognition must be a two-way street. To understand racial issues as, say, economic, is equally to understand economic issues as irreducibly racial. You can’t have one without the other. As I said to someone else here - maybe you already - economics and race are not in competition with one another. They must be thought through together, and each can only ever be conceived more poorly without the other.

@“Brett” got confused earlier when I said that something can be specifically racial without only being about race. Another way to put this is that not even racial issues are themselves purely racial. “Race”, isolated from its social links, is purely imaginary. But again, this means that the social is directly racially implicated. You can’t have it both ways. You can’t say that race issues are ultimately economic issues, while aiming to minimise any discussion of race in economics. If anything, the exact opposite holds. — StreetlightX

Yes I know you get it, more than most here probably, and that you are not arguing that point... but what form political action will take, will likely not be decided by your or my understanding of the problem, but by how it is perceived in the public. And the way it has played out so far, it seems to be predominately about race, which I don't disagree is a part of it, but it does risk missing the other aspect, especially in the measures that will be taken ultimately.

So I guess my point is more about strategy of political action than the 'truth' of the matter, which feels kinda dirty saying aloud, but still worth saying I think.... maybe not so much on a philosophy forum :-).

As far as I'm concerned, resistance to understanding things in terms of race comes out of nothing but a deep anxiety over it. Black people - and basically anyone who is not white - always get pinned down to their race: being black means you are a 'black writer', a 'black lawyer', a 'black actor' or whathaveyou. Being white just means you're a writer, lawyer, or actor. The resistance to race is nothing but the terrifying idea that one might have to be a 'white writer', etc etc. It's self-anxiety reflected outwards. "Pragmatisim" means: I don't want to have to deal with race - only they need to. — StreetlightX

For some that is clearly the case, I won't deny that... but for some (and I would count myself in that categorie lol) it's not so much that we have anxiety over race or that we want deny moral responsibility, but more that we think that race is not the most important aspect of the problem. And more importantly that we think that dealing with it as purely a race issue won't really solve it long-term. The way people perceive the problem will have its consequence for the measures that will be proposed ultimately. And like I said in the other thread, I think poverty is the real problem here. In the end those lone-sharks, slumlords, etc... that are the agents of systemic racism care about money, and they will make decision based on criteria that they think are an indication for that, like race. No amount of measures that deal strictly with race will change that it seems to me... and so the whole movement risks ending in something that only superficially deals with the problem, cosmetics.

There's only so much political capital and momentum to change things, and if that is spend on race-issues and identity-politics... chances are that poverty or more fundamentally the whole skewed capitalist system will not be dealt with. Another related point that I want to make is that I think time is running out. In marxist analysis, workers have the potential for political power because they have economic leverage... that is about to change rather fast as AI and automation become more mature. If it's hard to change the system with economic leverage, it's probably not getting any easier without it... and so from that perspective this seems like a bit of a wasted opportunity.

Do you agree or disagree with noAxioms earlier statement that "Under eternalism, we beings are worldlines"?
— Luke


To expand on this, if you exist at every moment of your worldline as a "space-time worm", i.e. you exist at every moment from your birth to your death, then what sense can it make to talk of moving through time from one moment to the next? Your physical existence, at least, exists as a four-dimensional object. What requires explanation in this scenario is why we have the conscious experience of time that we do; experiencing only one moment at a time in sequence, as though we are three-dimensional beings moving through time, and as though time actually does pass. — Luke

You know upon further consideration, I think there maybe is still something that needs to be explained, and that it 'why do we experience this particular moment of time (and not some other)?'.

I will try to come back to this later, I don't really have time now to break my head about the nature of time, but maybe I can say this already :

- The fact that we only experience one moment at a time in sequence, doesn't seem to be that big of a problem. That could easily be just a consequence of the limits of our experience, just like we only see or hear up to some distance in space, and not all of the universe at once.
- I still think movement (and temporal passage that is I think just an inference from seeing movement) is not a real issue for the eternalist, because things existing over different moments of time and positions in space, simply is movement in a 4d universe... and if we assume a limited perspective (which is what the assumption of eternalism entails) I don't see how that couldn't give rise to the same kind of experience like that of movement in a 3d presentist universe.

So you accept that all moments in time have the same existence and you accept that our perception of this is limited or 'illusionary'. But how do you get from there to the inference that we should expect to "experience things as moving through time"? — Luke

Maybe I didn't really answer this in particular. So we only experience one slice or one moment of time, at a time. But we also have a memory, we remember some of those experiences of moments at a time. And then there is also entropy always increasing, giving the appearance of directionality, (the textbook example being layered coffee and cream always tending towards totally mixed cream-coffee, but not the other way around). All of this together could give us the experiences we have of time passing, whether presentism is the case or whether eternalism is the case... both theories could fit our experience, we don't really know.

It's maybe somewhat similar to both flat earth theory and spherical earth theory fitting our basic experience of the surface we see being mostly flat (because a sphere with a big radius also looks flat from a certain perspective).

This also strikes me as backward. You're not making an inference that this is how we should expect to experience things; this is how we experience things, regardless of any metaphysical theory. — Luke

This is how (some) science works, that's not exactly backwards in the sense that you start from some observation and consistently derived theory from that observation. Take QM for instance, that is no metaphysical speculation because it is empirically tested that electrons behave according the the wavefunction. So then the question becomes, if it is a fact that electrons behave that way, why do we experience things fundamentally different on a macro level?

I'm not saying that eternalism is empirically verified or verifiable, and therefore not metaphysics, just that is this is the same type of reasoning... we try to explain how our experience fits into a theory that seems to fit other specific observations (in this case there is relativity, and the idea of a now not making sense in it, at least if you think of it as a non-local 'now').

And about the last part, this is something I already addressed in earlier posts, namely that I think you are viewing 4d from a 3d perspective... 4d existence is not static, it has time and movement included in existence.

This must be some sort of illusion, although nobody has offered any explanation of what type of illusion it is, or how the illusion of temporal passage in a static universe works. — Luke

That's because I don't think it really requires much additional explanation once you accept the basic premisses of eternalism, namely that all moments in time have the same 'existence'. If you accept that, you already assume that we don't see the entire picture, but only a slice of it at a time... and so you already accept that the way we perceive things is limited or 'illusionary'. That is the big one, and then it doesn't take that big of a leap that, given that assumption of limited perspective, we would experience things as moving through time.

Yes, I certainly don't disagree with the issues being put forward here, I'm just not sure I would call it racism as such. Well maybe it is... but in the end those slumlords, merchants, loansharks don't really care about race, I don't think, they care about the money, and race only play a role insofar they think it is an indication of how much money one has. So yeah, I think that problem could be largely solved with them not being poor.

Yes I actually agree they are intertwined... in Europe things are arguably somewhat similar with muslims, although to a lesser degree no doubt.

But maybe the point I want to make is that there used to be the kind of racism that was blatantly based on race. One was inferior based solely on the colour of their skin. Now it's more the kind of racism born out of 'induction', I think... some think blacks or muslims are inferior because they are generally poorer, have a lesser education and therefore also tend to turn to crime more often because they are poor. It's a vicious circle. So i guess what I'm saying is that this kind of racism is maybe better solved by addressing the poverty, instead of more of the same 'PC'-like measures.

Maybe it is a key element, I don't really know, I'm not an American, so I can't really say for sure.

But what i do know is that there is a temptation to paint something in a certain light for political reasons.

And I just think words have a certain meaning, and so does racism, and from what I've read on this thread the problem seem to have more to do with poverty. This poverty has its origins in racism for sure, but it doesn't seem clear to me that this is still the main problem. And so maybe it is better to call it what it is, so we know how to deal with it.

Maybe I'm totally off base, in that case I apologies for my ignorance.

for the fact that these structures have the same affect on blacks but in greater numbers - or rather in disproportionate numbers - that's just what systemic racism is.
— StreetlightX

Bingo. — Baden

Or we could just call it poverty, and probably have a more accurate description of the problem, so we know how to address it better.

Thanks, my mistake was indeed in thinking 'classical' worlds were created. This was really helpful, much appreciated.

Not quite. The cat branched when it "observed" (smelled) a system in superposition (between poison in the air and no poison in the air, resulting from broken vial and no broken vial, due to detection/no detection). That observation entangles the cat with this system, but that makes two "worlds". To the one Schrodinger, those two worlds are in superposition, until he opens the box; then his wavefunction entangles with this result, branching him into two Schrodingers. — InPitzotl

Alright, I'm not sure i'm getting it entirely yet. Does this mean that when something branches it doesn't create an 'entire world'? Say when the cat branches the wavefunction, there are two cats but still only one schrödinger until he observes it and 'joins' the two branches. Or does the cat observing it create a entire second world, and then two schrödingers observing it create another third and fourth entire world? I guess from your wording, it's the former?

Edit: Or I guess that there is yet another possibility that they each branch entirely seperately, and that branching does not create an entire world in each instance?

Which one? Dead cats tell to tales, but the living cat smells no poison. (make sure to see all edits above). — InPitzotl

So the branches are allready there before they 'branch'? Makes sense... for conservation of energy and the like.

"Normal sized living cat" is not in superposition; "normal sized cat" is (or more realistically, the contents of the box). The box is in a superposition between two states; A and B. State A has a living cat that smells no poison. State B has a dead cat in it. — InPitzotl

So then what does the cat in superposition experience, is still the question.

Normal sized Schrodinger's cat is in superposition; why would mini-electron sized cats be different? — InPitzotl

If a normal living cat is in superposition why doesn't it smell poison then? Doesn't superposition entail that it's neither exclusively living nor dead?

Living cats don't smell poison. — InPitzotl

Maybe hypothetical mini-electron sized cats do?

It only experiences something when it interacts with the screen it hits, and it only hits the screen at once place... per world. Exactly the distribution of places it hits across the possible worlds is what changes from its wavefunction's self-interaction, but it had a range of possible places it could have hit anyway before that.
— Pfhorrest

But it's a little person right, so it has eyes :-), what does it experience before the wavefunction collapses/splits, all possible positions at once... and then they all but one disappear when it hits the screen? — ChatteringMonkey

Or would it, because it has eyes instantly collapse/split because it gets entangled with itself and as such never see all positions at once?

It only experiences something when it interacts with the screen it hits, and it only hits the screen at once place... per world. Exactly the distribution of places it hits across the possible worlds is what changes from its wavefunction's self-interaction, but it had a range of possible places it could have hit anyway before that. — Pfhorrest

But it's a little person right, so it has eyes :-), what does it experience before the wavefunction collapses/splits, all possible positions at once... and then they all but one disappear when it hits the screen?

What's wrong with the premisses? — Luke

They apply to a presentist view only, and you are using them to arrive at a conclusion about motion in eternalist view.

I'm not even sure 'passage of time' the way you use it, is even essential to motion in a presentist view.

From wiki :

In physics, motion is the phenomenon in which an object changes its position over time. Motion is mathematically described in terms of displacement, distance, velocity, acceleration, speed, and time. The motion of a body is observed by attaching a frame of reference to an observer and measuring the change in position of the body relative to that frame.

There's no mention of anything like past, present or future in there.

I thought you agreed that there is no motion because time does not pass, and that this conclusion is already contained in the definitions? — Luke

Yes if motion is defined in presentist terms of passage of time, then yes that conclusion follows logically.

Logic only speaks to the validity of an argument. If there is something wrong with your premisses than the argument may be valid in that it follows logically, but that doesn't mean the conclusion is true. I'm saying there is something wrong with the premisses, not with the validity of the argument.

What I think you should say instead is something like this, 'in an eternalist view passage of time is replaced by things existing at different times' and motion is therefor re-defined as 'an object existing at different spaces and times'. This all a bit crudely formulated, but I'm just trying to get the point across.
— ChatteringMonkey

The passage of time is not "re-defined" under B-theory Eternalism. Time does not pass according to the B-theory. You seem to want to retain temporal passage in Eternalism, just as a different way of looking at it. No: If time passes, it's A-theory; if time doesn't pass, it's B-theory. You can't have it both ways. — Luke

I didn't say redefined, but replaced. There is an notion of time (nevermind the passage of time) in eternalism, right? So what i'm saying is that you should take that notion and how it's used in eternalism (and not the presentist notion) into account when you speak of stuff like motion in that view. That seems pretty uncontroversial to me.

The conclusion is allready assumed in the definitions, so what's there to talk about? — Luke

Sure, if you are content with logical formalism without necessarily saying anything about the world, then that works I suppose.

I wouldn't call it an assumption; it's how we experience the world. Nonetheless, there is no passage of time under B-theory Eternalism, so the assumption of a present moment is equally absent. I don't understand how this is problematic or meaningless. — Luke

It's problematic insofar you try to derive all sorts of things from it, like say that there is no motion.

If you only say 'there is no passage of time' therefor 'there is no motion' than that is mistake, maybe not strictly logically, but rather in how you didn't adjust the concepts to a different frame.

What I think you should say instead is something like this, 'in an eternalist view passage of time is replaced by things existing at different times' and motion is therefor re-defined as 'an object existing at different spaces and times'. This all a bit crudely formulated, but I'm just trying to get the point across.

I don't know what you mean by "the passage of time is not a meaningful thing to talk about in eternalism". — Luke

It's not meaningfull because it assumes there is a present moment. If there is no present moment what could passage of time possible mean?

However, if "Eternalism is a B-theory" and the B-theory is defined by "the absence of the passage of time", then time does not pass in Eternalism. Therefore, I argue, there is no motion in an Eternalist universe. That's what I'm arguing for here and what this discussion was supposed to be about. — Luke

But this is all per definition. The conclusion is allready assumed in the definitions, so what's there to talk about?

Well this was literally the first sentence of your OP:

Following from this and other discussions at this site, I wanted to lay out my view of why Eternalism logically precludes motion. — Luke

But yeah, I don't really care about metaphysical speculation. I'm only interested in eternalism because it seems to fit with our understanding of physics.

But the problem with metaphysical speculations and qualifications should be evident from this. If 1) B-theories are defined by the absense of the passage of time, and 2) Eternalism is a B-theory, but 3) the passage of time is not a meaningfull thing to talk about in eternalism… then maybe something is off with the whole qualification sceme.

Like, instead of insisting on using the qualifications and definitions you set out in the OP, and God forbid trying to logically proof something from them about eternalism, maybe you should be asking the question if they make sense to begin with. That's what I meant with engaging with the ideas, and not merely the pre-defined labels.

Yes i'm talking about eternalism, as per titel of the thread... and what we where talking about in most of the thread. Why are you switching to talking about B-theories in general?

Time doesn't pass according to the B-theory. That's it's defining aspect. Temporal passage was the first thing I defined in the OP and the thing I have had to keep repeating to you throughout this discussion. It also marks the difference between Eternalism and the Moving Spotlight theory, which was the intended topic of this discussion. But you seem to have wanted to talk about something else. — Luke

That's not its defining aspect, it's the lack of preferred moment, or a question of what exists. Time passing as you seem to use it doesn't make sense in an eternalist view, which is why I kept asking you what you actually meant with it.

To re-iterate, it's not that temporal passage does not exists in eternalism, it's that it's not a meaningfull thing to say.

Please enlighten me as to the difference between Eternalism and the Moving Spotlight theory. — Luke

Moving spotlight (and pretty much the rest of your list) has a preferred moment. Eternalism does not.

You seem to be implying that temporal passage is possible under Eternalism? How so?. - Luke

I implied no such thing. I said there is movement. I made no reference to temporal passage, which again is a term only meaningful to views that posit a preferred moment. — noAxioms

The fact that I don't subscribe to it, is evidence that I don't understand it?

And what do you think entertaining another perspective is?

Here's a quote from the only eternalist that posted in this thread, who said much of the same things I said :

In that case, my question is: when does motion occur according to Eternalism?
Somewhere between noon and 1 obviously (in my example). Every moment of it in fact, since at no time is any object actually stationary, what with Earth spinning and accelearting and all. — noAxioms

But believe what you want, I'm done.

Baden, probably true... it just seemed like the warning was out of place in a thread where everything seemed to be allowed. Now, I don't know what you actually already moderated out it of it, or what your history is with Chester, so maybe I don't have the full picture.

A case for that can't be made, assuming the baiting posts involved were in the systematic racism topic. What am I missing? — praxis

I think the warning pushed his buttons... not that he needed a lot of pushing probably, but still it seemed out of place to me in a thread that was not moderated at all it seems.

The gesture would seem much nobler if the high principled would at least wait for someone a bit better than Chester to be banned. Shouldn't have to wait long. — praxis

It isn't about Chester, it's about the modding. He was baited. The warning for excessive use of labels was ridiculously out of place considering all the labels that had already been thrown around, including and especially by the mods. It was an obvious abuse of power. Chester knew it... and flipped. Yes that's poor impulse controle on his part and he should be banned for that... but that's not the point. The point is that it's probably not a good idea to have mods baiting people into suicide by mod.

Do you believe that future events become present and then past? That's the passage of time; the thing you seem to have trouble to comprehend. If you believe in this, then you believe in temporal passage. This is what B-theorists do not believe. It's that simple. — Luke

Like I said I don't subscribe to any metaphysical theory of time. Strictly speaking the only thing I observe is things changing/moving. All the rest is I think a matter of convention. We measure change in units of time because it's useful for our purposes.... and we talk about past, present or future because we remember things that happened earlier. That is how we choose to split up things for utility purposes, but I don't think that necessarily says anything about the nature of things... I think we just don't know.

The Eternalist needs to account for how one moves from t1 to t2 if temporal passage is not real. — Luke

I don't see how that follows, one moves via all the intervals between t1 and t2.

Look, you said that "In 4d spacetime an object exists temporally extended, "wormlike" over time, but that doesn't mean it doesn't change, or that time doesn't pass... it does, per definition". I've shown you that this is incorrect. B-theorists assert that time does not pass. You can always opt for the Moving Spotlight theory if you want to retain temporal passage. — Luke

I don't think you have shown that. You seem to think that there is something fundamentally different about an object existing over all the intervals of time (t1, t2, t3, etc) and the passage of time, I don't. Time passes just the same, that's what the intervals of time indicate. Maybe 'passing' is a confusing word to use in an eternalist perspective because there isn't a preferred moment, but that's just a semantic issue, not necessarily because of some fundamental difference in how things move from one interval of time to another.

EDIT: And to clarify my position, I don't subscribe to any metapyiscal theory of time. I think time is a usefull convention at least. Maybe it's real, maybe not, I don't know and ultimately I don't think it really matters all that much for me as a human being.

It's a different type of existence compared to all other things which exist at a time. — Luke

Yes apparently, it just isn't clear to me what that would be.

You want me to entertain a perspective which is not the topic of this discussion? — Luke

Eternalism is the topic of the discussion.

None of this implies the ontological truth of one theory or the other. In fact, it doesn't even imply that time has an ontological nature. It might just be an ordering principle in our minds. — Echarmion

Yeah, that's where I'm at basically. Time is a usefull convention, regardless of it's ontological nature.

Is that a definition? — Luke

It's figure of speech, sort of, if you plot something in a graph along an axis that indicates different moments of time, then they move in time, and change. But whatever, it's not that important.

My concern, as presented in the OP, is with temporal passage and motion. I'm not sure whether "change" is really the same thing. Your use of this term seems to be a way for you to try and have both the A-theory and the B-theory. — Luke

Motion is a subset of change. And I use change instead of time, because it's the thing we observe, unlike time itself. But if you want, what I said works just as well with motion.

I don't. I deny that "the whole temporally extended object" changes at all. However, this might depend on your definition of "change". I'm not all that interested in change unless it means the same as temporal passage or motion. — Luke

It is the same with motion. You at time x1 and you at time x2 are at different locations, so you move. It doesn't make sense to say that 'the whole temporally extended object" doesn't move as a whole. To make that claim is to apply a 3d perspective on motion to 4d spacetime.

As I keep repeating, what it adds is the difference between the A-theory and the B-theory, which is temporal passage. A-theorists think it's real; B-theorists do not. It is not "just a question of what exists" if temporal passage is something over and above everything that exists. If it's not, then there's no distinction between B-theory Eternalism and the Moving Spotlight theory, which would imply there's no distinction between the B-theory and the A-theory. — Luke

Honestly, I have no idea whatsoever what you mean with temporal passage. Earlier I asked the question if you think time was something that exists independently, and you answered this:

I do not mean by it "that time is an independent metaphysical thing acting on the universe." — Luke

Now you say temporal passage is something that exists over and above everything else?

Either way, your last sentence doesn't follow. There is still a distinction between the theories because they have a different view of what exists, regardless of temporal passage.

A direction to time assumes temporal passage, which B-theorists reject. Entropy won't help you. To provide an account of why temporal passage has a direction is to concede that temporal passage is real. The Eternalist doesn't need to account for the direction of apparent temporal passage, but for apparent temporal passage itself (i.e. for how and why apparent temporal passage is not real). — Luke

Temporal passage again eh, if only I knew what it meant... I didn't say anything about temporal passage, I said time appears to have a direction because of entropy, and I think it can explain the direction just fine.

But I give up, like noAxioms said, you seem to be incapable of entertaining another perspective, and at this point i'm just repeating myself.

Per what definition? — Luke

The 4th axis of 4d spacetime.

You've introduced this talk of "change" rather than temporal passage. What changes about a space-time worm? Obviously, it has different parts at different times, but nothing about it changes. — Luke

The parts at different times are different right? Well, that simply is change. I don't know how to put it any other way really. Change is part of the thing that exists temporally extended. You cannot expect the whole temporally extended object to change in yet another 5th dimension. Then you are trying to apply a 3d presentist logic, where the time dimension isn't included yet, to 4d spacetime…. naturally that won't work.

As the SEP article notes, it's taking tense seriously, which means "the irreducible possession by times, events, and things of genuine A properties", which simply means that future events become present and then past. Genuinely! But I'm sure you already knew that. — Luke

I get that if you think only the present exist, the future and past are ontologically different... And so yes you would take tense seriously. But that is just a question of what exist, which I agree is different in the two theories. I'm just not sure what the word "genuinely" is supposed to add to all of this.

The passage of time is an intrinsic asymmetry in the temporal structure of the world, an asymmetry that has no spatial counterpart. It is the asymmetry that grounds the distinction between sequences which run from past to future and sequences which run from future to past. Consider, for example, the sequence of events that makes up an asteroid traveling from the vicinity of Mars to the vicinity of the Earth, as opposed to the sequence that makes up an asteroid moving from the vicinity of Earth to that of Mars. These sequences might be ‘matched’, in the sense that to every event in the one there corresponds an event in the other which has the same bodies in the same spatial arrangement. The topological structure of the matched states would also be matched: if state B is between states A and C in one sequence, then the corresponding state B* would be between A* and C* in the other. Still, going from Mars to Earth is not the same as going from Earth to Mars. The difference, if you will, is how these sequences of states are oriented with respect to the passage of time. If the asteroid gets closer to Earth as time passes, then the asteroid is going in one direction, if it gets further it is going in the other direction. So the passage of time provides an innate asymmetry to temporal structure. — Tim Maudlin

This is the temporal passage that B-theorists reject. — Luke

I agree that the eternalist need to give an explanation for the apparent asymmetry of time, which unlike space, seems to move only in one direction. But, as I alluded to in an earlier post, I think they probably can with the second law of thermodynamics. Entropy only increases, and so that gives time an apparent direction, only one way.