Eternalism vs Presentism?

[VikingF]

To the point:

IMHO the Block Universe is a remain of the belief that something can exist in 3D space only. The Block Universe is the image of a collection of stacked 3Dspaces the one above the other (or the one after the other). I think this is a wrong conception.

IMHO things exist in time first (that means vertically through the stacks) and then, eventually, horizontally (that is in 3d space). Existence means first displacement in time.

 

I don't see the difference. The block universe/Eternalism is the view that everything is four-dimensional, i.e. consisting of three spatial dimensions and one temporal dimension. Your view sounds like Eternalism.

Edited August 30, 2012 by VikingF

[Iggy]

If you think it is just a issue of grammar, you should read the paper I linked.

Yeah, apparently other people get the same impression,

 

These two authors claim that presentism and

eternalism are both essentially either vacuously true when viewed with the proper denition

of existence (for instance, to say that the present is the only thing that \exists now" is

tautological since \now" is dened in terms of the present) or analytically false when viewed

with the improper sense of existence (for instance, to say that the present is the only thing

that \exists tenselessly" is to ignore the past and future that are assumed in the phrase

\exists tenselessly").

 

In other words, there is no difference between presentism and eternalism if "the past exists tenselessly" is a meaningless thing to say. I'm quite sure it is. Even if "tenselessly" were a real word it wouldn't be a meaningful statement.

 

edited to add another snippet...

 

In an earlier paper , Dorato[10] brings in various other semantic arguments against

eternalism specically in an attempt to show how eternalism is as problematic as presen-

tism. The rst contention Dorato raises is against the eternalist perspective that \the

past, present, and future are all real at the same time", which he views as meaningless

since one cannot say anything about the relationship between the past, present, and future

at a given time since all three temporal regions cannot be simultaneous. There must be a

temporal separation between the past, present, and future for them to be well dened, so

any statement about how the past, present, and future interact at a given time collapses

this distinction and thus becomes meaningless.

 

This seems to me like the most obvious objection to any debate I've seen between the two

Edited August 30, 2012 by Iggy

[_heretic]

<snip>

 

Yup and the authors of that paper you are quoting make a good argument as to why that view, that there is no difference between Eternalism and Presentism, does not stand up; hence it is meaningful to consider Eternalism and Presentism as opposing and actually trying to describe reality.

[Iggy]

Yup and the authors of that paper you are quoting make a good argument as to why that view, that there is no difference between Eternalism and Presentism, does not stand up; hence it is meaningful to consider Eternalism and Presentism as opposing and actually trying to describe reality.

Indeed, but I can't have a discussion with a paper. Is it not an argument you'd be interested in making or discussing? I don't follow the semantics of the OP:

 

2. As I have considered it, Eternalism surely implies "eternal return" since it says that Shakespeare, for example, still exits (in the sense that the time point he's 'in' is as real as this one) and so could still be said to be writing plays.

 

What do you think? (I find myself more "aligned" to Eternalism, given what we know about space-time and relativity...

I don't understand the semantics of something like "the year 1616 still exists and is real" because it has a grammar problem. Nearly 400 years separate this post and the death of Shakespeare so it only makes sense for this post to say "the year 1616 did exist and was real" otherwise it conflates two different times... 2012 and 1616.

 

If you're considering it in terms of spacetime then I would say that the death of Shakespeare can't be found on the 2012 hyperplane on a spacetime diagram.

[_heretic]

Indeed, but I can't have a discussion with a paper. Is it not an argument you'd be interested in making or discussing? I don't follow the semantics of the OP:

 

 

I don't understand the semantics of something like "the year 1616 still exists and is real" because it has a grammar problem. Nearly 400 years separate this post and the death of Shakespeare so it only makes sense for this post to say "the year 1616 did exist and was real" otherwise it conflates two different times... 2012 and 1616.

 

If you're considering it in terms of spacetime then I would say that the death of Shakespeare can't be found on the 2012 hyperplane on a spacetime diagram.

 

It won't be found on the 2012 plane of course because you've sliced the 4D space-time there. But if you imagine your "outside" (in a 5th dimension perhaps!? ) then all the events would be there.

 

I'll make the argument from the paper in my own words if you want. Later anyway, it's late here and I'm tired (at time of posting) or maybe I should say _heretic is tired while posting this. (Keeping with the 4D of course )

[Iggy]

It won't be found on the 2012 plane of course because you've sliced the 4D space-time there.

By analogy, you don't have to slice up an office building to say that a certain chair is on one floor rather than the other.

 

But if you imagine your "outside" (in a 5th dimension perhaps!? ) then all the events would be there.

"The death of Shakespeare always exists" would make sense if the word "always" were used in the context of a second dimension of time in which the four dimensional event existed. There isn't a second dimension of time so it should not (and self-evidently doesn't) make sense to talk that way.

 

I'll make the argument from the paper in my own words if you want. Later anyway, it's late here and I'm tired (at time of posting) or maybe I should say _heretic is tired while posting this. (Keeping with the 4D of course )

 

I would enjoy it. You seem to know the issue.

[JMJones0424]

I've always had the impression that any debate between presentism and eternalism rests on grammatical errors. From the time and place that I'm writing this post it only makes sense to say "Shakespeare existed". It wouldn't make sense to say "Shakespeare, who died some time ago, still exists right now". Rather than being the basis of a philosophy, it looks more like a problem with grammar.

 

I wouldn't necessarily call it a grammatical error. If I understand the situation correctly, you have mis-characterized eternalism. Clearly, from your point of view, since the event of Shakespeare's death lies in your past, it is incorrect for you to claim that Shakespeare exists for you, right now. Instead, eternalism claims that because of special relativity, different observers cannot agree on whether or not Shakespeare is still alive, right now, for them.

 

Clipped from the paper linked by VikingF, Is There an Alternative to the Block Universe View?, on page 5

 

 

Let's say you are observer C, on Earth. I am observer A, moving at a relativistic speed towards you, and VikingF is observer B, moving at a relativistic speed away from you. VikingF and I cross paths in time and space at point M. At that moment, (when corrected for the finite speed of light) I observe you on Earth to make a post claiming Shakespeare is long dead at point Q. Simultaneous to me, VikingF also looks towards Earth (and after correcting for the finite speed of light) observes that tragically, Shakespeare has just died at point P. Though VikingF and I share the same present at point M, our "present"s intersect the Earth bound observer at radically different times.

 

Therefore, given Special Relativity, presentism cannot be a valid view. Of course, the explanation given in the paper is better, I have just adapted it to your narrative.

[Iggy]

I wouldn't necessarily call it a grammatical error. If I understand the situation correctly, you have mis-characterized eternalism. Clearly, from your point of view, since the event of Shakespeare's death lies in your past, it is incorrect for you to claim that Shakespeare exists for you, right now.

I think you misunderstand. I was responding to this:

 

2. As I have considered it, Eternalism surely implies "eternal return" since it says that Shakespeare, for example, still exits (in the sense that the time point he's 'in' is as real as this one) and so could still be said to be writing plays.

 

If that is a mischaracterization because Eternalism doesn't in fact say that then the mischaracterization isn't mine. However, I don't believe Heritic is mischaracterizing it. Eternalism is often summarized in that way. The source I quoted in the post you responded to says:

 

According to Eternalism, non-present objects like Socrates and future Martian outposts exist right now

 

http://plato.stanford.edu/entries/time/#PreEteGroUniThe

 

Instead, eternalism claims that because of special relativity, different observers cannot agree on whether or not Shakespeare is still alive, right now, for them.

 

Clipped from the paper linked by VikingF...

 

Let's say you are observer C, on Earth. I am observer A, moving at a relativistic speed towards you, and VikingF is observer B, moving at a relativistic speed away from you. VikingF and I cross paths in time and space at point M....

I don't think you read the rest of my post. It gives the same thought experiment,

 

I'm also not sure how presentism's most understandable claim "non-present objects don't exist" disagrees with relativity. Being specific and keeping the grammar straight makes it easy to say, "Socrates exists relative to a spaceship at a great distance from earth moving away from the earth". Relative to that spaceship Socrates exists in the present. Events in the life of Socrates and events on the spaceship are simultaneous relative to the spaceship. That wouldn't make Socrates a "non-present object". It would rather make him present relative to the ship. Relative to me writing this post Socrates is not present and does not exist. The claim "non-present objects don't exist" seems correct in both cases.

If a universal now is a tenant of presentism, I've never seen it presented that way. Their philosophy seems to follow from the claim "non-present objects don't exist" which is tautologically true for any observer in special relativity. There is no such thing as a non-local present in general relativity so the statement wouldn't be fitting with that theory.

[_heretic]

 

If a universal now is a tenant of presentism, I've never seen it presented that way. Their philosophy seems to follow from the claim "non-present objects don't exist" which is tautologically true for any observer in special relativity. There is no such thing as a non-local present in general relativity so the statement wouldn't be fitting with that theory.

 

If this really is what the position of Presentism is then it seems like a trivial view to take. Of course an observer will think of objects that are not in their plane of simultaneity as existing, but then another observer could think of them as existing since those very same objects will be present in their plane of simultaneity! So what is the objective criterion for whether something exists or not? Otherwise aren't we pushed into the position where we must concede that every event/object does in fact exist; which is the Eternalist view.

[VikingF]

I think this boils down to how we define the word "exist". If by "exist" we mean "simultaneous in my reference frame" (existing right now for me), then surely, Shakespeare does not exist. However, if by "exist" we mean "simultaneous in any reference frame" (existing in spacetime), then he does indeed exist, since simultaneity is relative based on which reference frame you are in. Shakespeare is certainly existing in the spacetime, whether or not he is existing "right now" in my frame of reference.

 

The main difference between Presentism and Eternalism is really about whether time is an own dimension or not. Presentism says "no, time is just a measurement of changes in space", while Eternalism says "yes, time is a temporal dimension containing all events that have happened, are happening, and will happen, and "now" is not a privileged point of time".

Edited September 1, 2012 by VikingF

[_heretic]

I think this boils down to how we define the word "exist". If by "exist" we mean "simultaneous in my reference frame" (existing right now for me), then surely, Shakespeare does not exist.

 

The problem with this is, yes Shakespeare may not "exist" in your reference frame, but he does in fact exist in a different reference frame. So does this mean that Shakespeare both exists and does not exist...?

 

 

[VikingF]

The problem with this is, yes Shakespeare may not "exist" in your reference frame, but he does in fact exist in a different reference frame. So does this mean that Shakespeare both exists and does not exist...?

 

You have to choose your definitions first. If to exist is to exist in spacetime, then he exists.

Edited September 1, 2012 by VikingF

[LaurieAG]

Hi _heretic,

 

In what way is it a "bridge"? (And what do you mean by that?)

 

It's probably more of a mental bridge so I will describe a loose example of a similar quantum bridge that I saw in an episode of an anime called 'the enigmatic giant'.

 

The giant says 'Make a statement to cross the bridge, if you tell the truth I will strangle you but if you tell a lie I will stab you with my sword'.

 

The statement that allows you to cross the bridge is 'you will stab me with your sword'. If the giant does stab you with his sword then what you said would be true and he would have broken his own rules as he should have strangled you instead.

Edited September 2, 2012 by LaurieAG

[_heretic]

Hi _heretic,

 

 

 

It's probably more of a mental bridge so I will describe a loose example of a similar quantum bridge that I saw in an episode of an anime called 'the enigmatic giant'.

 

The giant says 'Make a statement to cross the bridge, if you tell the truth I will strangle you but if you tell a lie I will stab you with my sword'.

 

The statement that allows you to cross the bridge is 'you will stab me with your sword'. If the giant does stab you with his sword then what you said would be true and he would have broken his own rules as he should have strangled you instead.

 

Okay so you meant a mental bridge between the two philosophical viewpoints on the ontology of time. But in what way is a Wick Rotation this bridge? Are you saying that the Wick rotation somehow reconciles the two views? And if so, how does the Wick Rotation do this?

 

You have to choose your definitions first. If to exist is to exist in spacetime, then he exists.

 

Surely the only valid definition of existence is whether something is physically "there" in the spacetime. e.g. Nowhere in the spacetime does there exist a flying spaghetti monster therefore the FSM does not physically exist. On the other hand, there does exist, somewhere, in the spacetime Tim Berners-Lee therefore Tim Berners-Lee exists.

[Iggy]

If this really is what the position of Presentism is then it seems like a trivial view to take.

and I think they want it to be much less trivial, but I'm not sure it is. What I meant to say before, but couldn't find the words, is that I don't see any falsifiable differences between the consequences of the two philosophies, but I guess it does indeed depend on how the philosophies are interpreted.

[LaurieAG]

Okay so you meant a mental bridge between the two philosophical viewpoints on the ontology of time. But in what way is a Wick Rotation this bridge? Are you saying that the Wick rotation somehow reconciles the two views? And if so, how does the Wick Rotation do this?

It is a bridge because it effectively brings the equations down one dimension and removes the imaginary unit i.

 

Wick rotation relates statics problems in dimensions to dynamics problems in dimensions, trading one dimension of space for one dimension of time.

This rotation is of interest structurally in that normally an indefinite integral with infinite limits is considered undefined in calculus unless it is a sub part of a higher level cyclic function, that went from one limit to the other during each cycle. If this calculus was not available the imaginary unit i could not be used in any conversion. I'm not sure if an indefinite integral, whose higher level function equates to one cycle, should be considered an improper integral rather than being undefined.

Edited September 3, 2012 by LaurieAG

[_heretic]

It is a bridge because it effectively brings the equations down one dimension and removes the imaginary unit i.

 

 

This rotation is of interest structurally in that normally an indefinite integral with infinite limits is considered undefined in calculus unless it is a sub part of a higher level cyclic function, that went from one limit to the other during each cycle. If this calculus was not available the imaginary unit i could not be used in any conversion. I'm not sure if an indefinite integral, whose higher level function equates to one cycle, should be considered an improper integral rather than being undefined.

 

I had always the thought the Wick rotation was just a mathematical convenience; not actually representing an objective, physical process. Am I mistaken?

[VikingF]

Surely the only valid definition of existence is whether something is physically "there" in the spacetime. e.g. Nowhere in the spacetime does there exist a flying spaghetti monster therefore the FSM does not physically exist. On the other hand, there does exist, somewhere, in the spacetime Tim Berners-Lee therefore Tim Berners-Lee exists.

 

Of course, but I meant the difference between being somewhere in spacetime, and at this specific point of time in spacetime. Shakespeare exists in spacetime, but not at this very point of time. According to Presentism, he doesn't exist at all, because they do not believe in a four-dimensional spacetime, hence for something to exist, it has to exist now.

Edited September 4, 2012 by VikingF

[LaurieAG]

I had always the thought the Wick rotation was just a mathematical convenience; not actually representing an objective, physical process. Am I mistaken?

Stephen Hawking discussed applying the Wick rotation to Lorentzian metrics with Roger Penrose in their lecture series, 'The Nature of Space and Time' in 1996, but I am unsure if anything has been developed further along these lines. There is also the issue about the bits that do not translate into reality in euclidian space but any objective, physical process, as you say, would have to consider how these anomalies would be treated in reality.