Does the Block Universe Theory Affect Our Understanding of Time and Reality?

[Dale]

If the thought experiment outcome does not contradict LET, that just means that LET also requires 4-dimensional objects.

No, LET uses a model with a 3D reality which evolves over time, where time is the time in the aether frame. The worldline of any point particle can be written as a parameterized 1D object in a 4D space $(t(\tau),x(\tau),y(\tau),z(\tau))\in \mathbb{R^4}$ or as a 0D object in a 3D space which evolves over time $(x,y,z)\in \mathbb{R^3}(t)$. There is no way to distinguish the two experimentally.

 

[Dale]

I take it from the way you stated this that you at least acknowledge that we have established that Light Brown, as a minimum, has been shown to exist at two events along his world line, one being simultaneous with Brown and the other being simultaneous with Blue while Brown and Blue share their intersection event.

No, Light Brown has been shown to have existed at two past events. This does not imply anything about his current or continuing state of existence. The data is perfectly consistent with a 3D world which evolves over time.

Although you are correct that it is hard to explain the block universe concept in ordinary language (which is why it is best to use mathematical notation as above) it is not hard to explain the evolving 3D universe concept in ordinary language and see that it is also consistent with the data.

 

[Chestermiller]

The problem isn't that the experiment produces a negative result, the problem is that any alternative Lorentz-compatible model will also predict a positive result. For instance, LET would also predict a positive result.

This seems to be a key point that DaleSpam has raised. I would like to paraphrase it to test my understanding of what he is saying: The Block Universe model was originally developed as a way of translating the mathematical language of the Lorentz Transformation into a verbally articulated mechanistic physical model that could possibly represent physical reality (and that, possibly, people could more easily relate to). As such, it automatically and flawlessly must agree with every conceivable prediction that can be obtained from the Lorentz Transformation (including the thought experiments described by bobc2). However, back in the day, another verbally articulated mechanistic physical model, the LET model, was also developed, and it too is totally consistent with all possible predictions from the Lorentz Transformation. The verbally articulated descriptions for the Block Universe model and the LET model are very different from one another mechanistically, the former being a 4D geometric model, and the latter being an exclusively 3D description. Unfortunately, any thought experiments that agree with the Lorentz Transformation can not be used as a method of distinguishing which, if either of the two descriptions, provides a better representation of physical reality. There may be other equally valid mechanistic equivalents of the Lorentz Transformation that would also be in the running.
From this, I think it follows that, if mechanistic models such as these are to be tested to determine which if any are better representations of physical reality, we must look to experiments beyond the realm of SR, such as those which require application of GR; even there it might be very difficult to provide resolution.

 

[Dale]

I would like to paraphrase it to test my understanding of what he is saying: The Block Universe model was originally developed as a way of translating the mathematical language of the Lorentz Transformation into a verbally articulated mechanistic physical model that could possibly represent physical reality (and that, possibly, people could more easily relate to). As such, it automatically and flawlessly must agree with every conceivable prediction that can be obtained from the Lorentz Transformation (including the thought experiments described by bobc2). However, back in the day, another verbally articulated mechanistic physical model, the LET model, was also developed, and it too is totally consistent with all possible predictions from the Lorentz Transformation. The verbally articulated descriptions for the Block Universe model and the LET model are very different from one another mechanistically, the former being a 4D geometric model, and the latter being an exclusively 3D description. Unfortunately, any thought experiments that agree with the Lorentz Transformation can not be used as a method of distinguishing which, if either of the two descriptions, provides a better representation of physical reality. There may be other equally valid mechanistic equivalents of the Lorentz Transformation that would also be in the running.

Sounds right to me.

 

[bobc2]

Chestermiller, I didn't intend to take over your thread. There seemed to be two questions in your mind about the block universe: 1) What is it understood to represent in the physics community (and is your understanding of the concept in agreement with this)? and 2) What are the implications of the concept?

I tried to present the concept for you and indicate the motivation and validation of the concept. Since I've already dominated more than my share of the thread, I'll leave it to others to respond to your second question.

I think at this point you have enough of my views and the opposing views to draw your own conclusions about the validity of the concept. I'll just provide you a summary of the views I've expressed, presenting again the earlier sketches (which, by the way, are not at all original with me). The thrust of my presentations is that special relativity requires a universe populated by 4-dimensional objects, all of which co-exist in block time.

 

[Dale]

The thrust of my presentations is that special relativity requires a universe populated by 4-dimensional objects, all of which co-exist in block time.

If you would change "requires" to "permits" or "suggests" or something similar then I would agree. As it is, I think it is pretty clear that "requires" is too strong.

 

[harrylin]

The problem isn't that the experiment produces a negative result, the problem is that any alternative Lorentz-compatible model will also predict a positive result. For instance, LET would also predict a positive result.

In order for an experiment to qualify as evidence for theory A over theory B then not only does it need to be in accordance with theory A but it must also be in contradiction to theory B. That is what yuiop was mentioning:

Yes, and we have discussed that exact same topic not long ago.
- https://www.physicsforums.com/showthread.php?p=3558212 #27

Now, as different models claim to be consistent with SR (and all those interpretations are very hard or impossible to disprove), we call it "philosophy". Nevertheless, it's not the "empty" kind of philosophy that most of us don't appreciate that much, but philosophy of physics (in that sense I somewhat agree with both Ben and Bobc2). And if physics students don't learn it -just as my physics books omitted it- then they may be confronted with conceptual problems later on.

Harald

PS: Bob2c, I am again flabbergasted by your presentation today, in view of our earlier discussion in which you commented:
"I have tried and tried for many years to find material that effectively counters it, without success. I've tried to think up scenarios without success. I can't counter the argument for the block universe, but at the same time I just don't see how we can reconcile it when you consider the bizarre implications."
Upon that several of us presented alternative views; you may adhere to that view that you say you don't like, but there is no need for it.

 

[Dale]

I agree, and I think that it is beneficial to learn as many different interpretations as possible. I hope bobc2 continues to discuss the block universe interpretation and explain it to interested people.

 

[harrylin]

[..] Unfortunately, any thought experiments that agree with the Lorentz Transformation can not be used as a method of distinguishing which, if either of the two descriptions, provides a better representation of physical reality. There may be other equally valid mechanistic equivalents of the Lorentz Transformation that would also be in the running.
From this, I think it follows that, if mechanistic models such as these are to be tested to determine which if any are better representations of physical reality, we must look to experiments beyond the realm of SR, such as those which require application of GR; even there it might be very difficult to provide resolution.

Yes, the main contender of today is, I think, the one thought up by Bell (search for Bell Theorem, I also started a new topic on it in the QM group). Bell favoured the "older" interpretation and thought to have found a proof for that in QM. However, while I also think that the older interpretation makes more sense, his solution doesn't make much sense to me - it's as Einstein called it, a "spooky" solution and I'm not (yet) convinced that his theorem is faultless for sure.

 

[bobc2]

I agree, and I think that it is beneficial to learn as many different interpretations as possible. I hope bobc2 continues to discuss the block universe interpretation and explain it to interested people.

Thanks, DaleSpam. You always play fair.

 

[bobc2]

...PS: Bob2c, I am again flabbergasted by your presentation today, in view of our earlier discussion in which you commented:
"I have tried and tried for many years to find material that effectively counters it, without success. I've tried to think up scenarios without success. I can't counter the argument for the block universe, but at the same time I just don't see how we can reconcile it when you consider the bizarre implications."
Upon that several of us presented alternative views; you may adhere to that view that you say you don't like, but there is no need for it.

You may have missed a couple of the posts where I commented about caution--that physics does not yet have a complete understanding of time and certainly not consciousness.

But you are right. I have reservations and am mostly puzzled by the mystery presented to us by special relativity. I think its mystery is equal to that of QM. On the one hand we have the compelling concept of the block universe, while our deepest instincts and experience react against that concept (our "...stubbornly persistent illusion"). And along with the stubbornly persistent illusion are troubling implications of the block model, such as the zombies and threat of solipsism.

At the same time when it is time to present the block universe concept, I try to give it my best shot, although in the final analysis I don't really know the answer. But, what I personally believe is not that relevant--I'm certainly not an authority in this area, so I would rather present the views of physicists who have established reputations.

 

[harrylin]

[..] I have reservations and am mostly puzzled by the mystery presented to us by special relativity. I think its mystery is equal to that of QM. On the one hand we have the compelling concept of the block universe, while our deepest instincts and experience react against that concept (our "...stubbornly persistent illusion"). And along with the stubbornly persistent illusion are troubling implications of the block model, such as the zombies and threat of solipsism.

At the same time when it is time to present the block universe concept, I try to give it my best shot, although in the final analysis I don't really know the answer. But, what I personally believe is not that relevant--I'm certainly not an authority in this area, so I would rather present the views of physicists who have established reputations.

That's fine, but why do you present it in a biased way, as if it is proven to be the "correct" view? In fact, SR doesn't require "the reality of the 4-dimensional bodies" (post #24). Are you just playing "the Devil's advocate" perhaps?

My approach is very different from yours: if I am first presented with an explanation that doesn't make much sense to me, and after more reflection, for some subtle reasons appears to be simply wrong; and later another one that looks less appealing but which makes perfect sense, then I'm happy to have a way to understand it. And I offer it to whoever wants it, but without pushing it. And I hope one day to similarly understand QM - in a way that makes sense to me.
So, it's a bit funny - almost paradoxical - to see you pushing a model that you find puzzling, and me not pushing a model that makes perfect sense to me.

 

[Chestermiller]

Chestermiller, I didn't intend to take over your thread. There seemed to be two questions in your mind about the block universe: 1) What is it understood to represent in the physics community (and is your understanding of the concept in agreement with this)? and 2) What are the implications of the concept?
Since I've already dominated more than my share of the thread, I'll leave it to others to respond to your second question.

Thanks bobc2. I have found your discussions in this thread very educational, and they have helped me get a much better understanding of the Block Universe model. Thanks also for your courteous and respectful responses.
As you mentioned, in my original posting, I offered some extended interpretations which seem to be fully consistent with the Block Universe material that you presented. These interpretations are totally new (I think), within the framework of Block Universe, and I was hoping that some PF respondents would be willing to comment on them. Looking forward to hearing from some of you.

Chet

 

[bobc2]

That's fine, but why do you present it in a biased way, as if it is proven to be the "correct" view? In fact, SR doesn't require "the reality of the 4-dimensional bodies" (post #24). Are you just playing "the Devil's advocate" perhaps?

I'm not sure really. Aside from trying very hard to provide a good representation of the block concept, it's probably that I'm so conflicted about it. When in the process of really focusing on just the logic of the concept it kind of takes over my thought process. I get so convinced of the logic that I presented in the summary post, I'm probably really believing it at that point. Then, after pulling away and thinking about some of the bizarre implications I get quite a bit more subjective in the analysis. You might say that on an objective basis I can't find a way to refute the logic of block universe, yet, on a subjective basis I reject it. I don't know if that makes any sense, but I can understand your puzzlement over some of my posts.

 

[bobc2]

Chestermiller, I didn't intend to take over your thread. There seemed to be two questions in your mind about the block universe: 1) What is it understood to represent in the physics community (and is your understanding of the concept in agreement with this)? and 2) What are the implications of the concept?
Since I've already dominated more than my share of the thread, I'll leave it to others to respond to your second question.

Thanks bobc2. I have found your discussions in this thread very educational, and they have helped me get a much better understanding of the Block Universe model. Thanks also for your courteous and respectful responses.
As you mentioned, in my original posting, I offered some extended interpretations which seem to be fully consistent with the Block Universe material that you presented. These interpretations are totally new (I think), within the framework of Block Universe, and I was hoping that some PF respondents would be willing to comment on them. Looking forward to hearing from some of you.

Chet

Thanks for your consideration (and endurance through the extended posts). I hope you will get some more feedback on the ideas you've presented--and perhaps some comments on some of the implications of the block concept.

 

[harrylin]

[..] When in the process of really focusing on just the logic of the concept it kind of takes over my thought process. I get so convinced of the logic that I presented in the summary post, I'm probably really believing it at that point. [..]

OK, that explains it - thanks for the clarification!
And surprisingly not many people here take the time to defend the Block Universe concept, so I think that your elaborations are very useful.

 

[Vandam]

OK, that explains it - thanks for the clarification!
And surprisingly not many people here take the time to defend the Block Universe concept, so I think that your elaborations are very useful.

People who accept the real significance of "relativity of simultaneity" know that Block Universe is a fact.

 

[nitsuj]

People who accept the real significance of "relativity of simultaneity" know that Block Universe is a fact.

Hmmm, I don't. Perhaps I don't know RoS, or at least the real significance.

Block universe a fact? A fact of what? and according to what/whos measure of time?

 

[harrylin]

Hmmm, I don't. Perhaps I don't know RoS, or at least the real significance.

Block universe a fact? A fact of what? and according to what/whos measure of time?

I second that - IMHO, the real significance of RoS depends on one's interpretation, so that such an argument is bound to involve circular reasoning.

And there is a follow-up thread (also still open) with more discussion on the sub-topic of RoS as supposed evidence for the Block Universe, based on Paul Davies claims:

https://www.physicsforums.com/showthread.php?t=595021

 

[Dale]

People who accept the real significance of "relativity of simultaneity" know that Block Universe is a fact.

There is no experiment which can be performed to distinguish the block universe interpretation of SR from other interpretations of SR. So, no, it is not a fact, even given the relativity of simultaneity. The block universe happens to be my preferred interpretation, but I am not deluded enough to call it a fact.

 

[nitsuj]

The block universe happens to be my prefered interpretation,

and then it was and lastly but then :zzz: 'cause this ground has been covered many times.

I wouldn't have guessed you to prefer an Eternalism interpretation of time.

 

[Dale]

and then it was and lastly but then :zzz: 'cause this ground has been covered many times.

I wouldn't have guessed you to prefer an Eternalism interpretation of time.

Sorry to cause such distress!

I probably should mention that my preference is practical rather than philosophical. Specifically, I simply find it easier to correctly work most problems by using the block universe interpretation to organize my thinking than by using others. I don't particularly "believe in" any interpretation philosophically and so I shamelessly use other interpretations (even LET) whenever they suit the particular problem at hand.

 

[nitsuj]

Sorry to cause such distress!

I probably should mention that my preference is practical rather than philosophical. Specifically, I simply find it easier to correctly work most problems by using the block universe interpretation to organize my thinking than by using others. I don't particularly "believe in" any interpretation philosophically and so I shamelessly use other interpretations (even LET) whenever they suit the particular problem at hand.

Now that's a "Dalespam" response, thanks I feel better now!

 

[bobc2]

People who accept the real significance of "relativity of simultaneity" know that Block Universe is a fact.

Vandam, you are actually in pretty good company, embracing the Block Universe concept: Physicists and mathematicians like Einstein, Hermann Weyl, Kurt Godel, and many others. Einstein commented that General Relativity would not have got any father than its long clothes without Minkowski's 4-dimensional continuum of special relativity.

 

[PeterDonis]

Einstein commented that General Relativity would not have got any father than its long clothes without Minkowski's 4-dimensional continuum of special relativity.

I don't think Einstein was talking about the "block universe" concept in that quote, at least not as "block universe" is being used in this thread. "Block universe" is an *interpretation* of what 4-d spacetime, as it's used in SR and GR, means. Einstein was just talking about the theoretical usefulness of 4-d spacetime, in particular how viewing it as a geometric object opened the door to letting that geometric object be dynamic instead of fixed, which led to GR. Einstein was not talking about any particular interpretation of what 4-d spacetime means.

 

[bobc2]

I don't think Einstein was talking about the "block universe" concept in that quote, at least not as "block universe" is being used in this thread. "Block universe" is an *interpretation* of what 4-d spacetime, as it's used in SR and GR, means. Einstein was just talking about the theoretical usefulness of 4-d spacetime, in particular how viewing it as a geometric object opened the door to letting that geometric object be dynamic instead of fixed, which led to GR. Einstein was not talking about any particular interpretation of what 4-d spacetime means.

In my response to Vandam's post I was trying to assure him that he is not alone in his feelings about the block universe. And there is some support for the view that Einstein embraced the concept. Here are excerpts from the other block universe link the you mentioned earlier. They go to the notion that Vandam should not feel alone in his views.

Paul Davies: The idea that events in time are laid out ‘all at once’ motivated Einstein to write the words… “The distinction between past, present and future is only an illusion, even if a stubborn one.”

Paul Davies: “…there is only one rational conclusion to draw from the relative nature of simultaneity: events in the past and future have to be every bit as real as events in the present.”

Paul Davies: “Einstein himself wasn’t too thrilled with the unified spacetime idea at first, dismissing Minkowski’s new four-dimensionality as ‘superflous’ pedantry, but he came around to the idea in due course.”

Paul Davies: ”Weyl once wrote: ‘The world does not happen, it simply is.’ If you believe Weyl, Einstein did; hence the quote penned in consolation to Besso’s widow following his death: ‘The distinction between past, present and future is only an illusion, even if a stubborn one.’

Paul Davies: “In their professional lives most physicists accept without question the concept of the block time, but away from work they act like everybody else, basing their thoughts and actions on the assumption of a moving present moment.”

Paul Davies: “I have already explained how the theory of relativity leads to the notion of block time, and the picture of time as the fourth dimension simply ‘laid out all at once.’ Since Einstein, physicists have generally rejected the notion that events ‘happen,’ as opposed to merely exist in the four-dimensional spacetime continuum.”

Paul Davies: “David Park is a physicist and philosopher at Williams College in Massachusetts with a lifelong interest in a time which he too thinks doesn’t pass. For Park, the passage of time is not so much an illusion as a myth, ‘because it involves no deception of the senses… One cannot perform any experiment to tell unambiguously whether time passes or not.’ “

“When it comes to the truly objective properties of the world, reference to the flow of time appears superfluous.”

Paul Davies: “Einstein scuttled the notion of a universal now, and pointed the way to ‘block time,’ in which all events—past, present and future—are equally real. To the physicist, human beings of the twenty-fifth century are ‘there’… They are there in the future.”

 

[nitsuj]

Vandam, you are actually in pretty good company, embracing the Block Universe concept: Physicists and mathematicians like Einstein, Hermann Weyl, Kurt Godel, and many others. Einstein commented that General Relativity would not have got any father than its long clothes without Minkowski's 4-dimensional continuum of special relativity.

I've read some wiki about "block universe"; it is seems to me to be a sort of "anti-continuum".

I am of the mind set the universe is a 4D continuum, and not a static block that plays tricks with the measurements/observations we make of time, noting a distinct (but not absolute) future-past continuum.

From the "perspective" of EM and whatever else maybe at that end of the time/length "spectrum" eternalism seems fine to me. I kinda like the PoV that "energy" "flows" at c, and from a causation perspective is an example of "eternalism". but isn't that,clearly, only one perspective of multiple measurable/observable dimensions?

imo bobc2, I think both physically & philosophically our minds have a better grasp of the 4D's, specifically time, than you give it credit for.

Paul Davies: The idea that events in time are laid out ‘all at once’ motivated Einstein to write the words… “The distinction between past, present and future is only an illusion, even if a stubborn one.”

RoS is plenty for all those "Einstein tidbits" in your #61 post, "Eternalism" is just some added poetry, added after the poor fellow cannot speak for himself. In addition I would guess Einstein was purposefully coy with that comment.

 

[Austin0]

But the point of the space-time diagram is that both events, R1 and R2, exist and are real, and the Red guy exists and is real at both R1 and R2 events. That is, when the brown guy and the blue guy meet, R1 exists in Blue's instaneous 3-D world while R2 exists in Brown's instantaneous simultaneous world.

Don't overcomplicate the problem by asking what you mean by real. I think we all know what we are talking about. We simply use a protype example of real. When Blue and Brown meet, Brown observes that Blue is a real observer and Blue observes that Brown is a real observer. If you and I are standing in a room talking, I identify you as a real body and you identify me as a real body--that's our prototype example of real--unless you are a Solipsist--but Einstein was quite emphatic about prohibiting solipsism in relativity).

Now, it is not a question of whether Brown or Blue correctly identifies the Red observer as being real. Both Brown and Blue are correct in observing that a real Red body exists in their respective 3-D worlds at the event of Brown's and Blue's world lines intersecting (Brown and Blue meet).

That's the whole point of the block concept: the Red body must be a 4-dimensional body for both Brown and Blue to each have Red existing as a 3-D body in their respective instantaneous 3-D worlds. Brown and Blue each observe a different 3-D cross-section of Red's 4-dimensional body.


Again, by extension, we could keep adding more and more observers with different Lorentz boosts until the original Red world line is seen to be a continuous 4-dimensional body, i.e., a real physical body extending continuously along Red's world line. We could then develop the concept for every other observer and every other object in the universe until we recognize the entire universe is 4-dimensional populated by 4-dimensional objects. That's the block universe concept.

I thought you got the concept in that other thread that simultaneity was not transitive in SR So R1 being simultaneous to R according to Blue's clocks and R2 being simultaneous to R by Browns clocks does NOT mean that R1 and R2 are simultaneous.
Any such statement is totally in contradiction of fundamental SR which says that any evaluation of distant events regarding temporal relationship is purely conventional and without any real temporal meaning.
In this case Both Red and Brown would disagree with Blue that R1 and R were simultaneous.
Both Red and Blue would disagree with Brown that R2and R were simultaneous.

So you have just selectively chosen two arbitrary frame evaluations of a set of events,applied an interpretation of actual simultaneity to the clocks in both Blue and Brown systems which is against the principles of SR and then concluded that this is proof that SR necessarily implies a Block Universe.
To me this appears self evidently circular. Applying the block time interpretation and expectations to SR to prove block time,ignoring the fact that this contradicts fundamental SR principles in the process.

 

[bobc2]

I've read some wiki about "block universe"; it is seems to me to be a sort of "anti-continuum".

I am of the mind set the universe is a 4D continuum, and not a static block that plays tricks with the measurements/observations we make of time (past-future).

Hi, nitsuj. It's always good reading your posts. Actually, the block universe concept is definitely based on the continuum concept. Einstein never would relenquish his continuum, and insisted it must be that way. I recall a specific reference, but will have to look it up to make sure I'm presenting it correctly.

From the "perspective" of EM and whatever else maybe at that end of the time/length "spectrum" eternalism seems fine to me, but isn't that,clearly, only one perspective of multiple measurable/observable dimensions?

imo bobc2, I think both physically & philosophically our minds have a better grasp of the 4D's, specifically time, than you give it credit for.

You may have a good point there. I have trouble working through the concept of time as the 4th dimension and various observers having different cross-section views of space-time, with different "mixtures" of space and time.

I can easily handle the process of watching a woven waste basket sitting statically over in the corner of my room while time is passing. But, it's much easier for me to handle conceptually by thinking of the basket extended into the 4th dimension as a 4-dimensional structure (the spaghetti-like picture represented by the world line extending 10^13 miles along the 4th dimension).

In that picture the 4-dimensions are all spatial and the 4-D basket just sits in 4-D space while time passes. But, evidently, that is not the picture that Einstein and all physicists subscribe to. So, in that sense, I'm presenting a speculative concept, which I really don't wish to do on this forum. Einstein definitely refers to space-time with time as the 4th dimension (I know of a reference for this comment, but again it would take a little while to dig it up).

 

[nitsuj]

I had typed up a somewhat lengthy post explaining my interpretation and how it's not compatible with "eternalism".

But luckily had re-read Dalespams post a realized I was merely being opinionated in a physics thread.

bobc2 I do find the Block Universe interpretation fascinating, but philosophically (and from a physics perspective) I don't subscribe.

I am sure you can appreciate the difficulty in conveying such a complex interpretation as "eternalism" in particular via typing it out. You seem to have a deep grasp of the Block Universe Concept and feel strongly about it. Who am I to try and "knock" that, I have no authority on the subject.

So this is all that is left of that "lengthy" post.

 

[harrylin]

Vandam, you are actually in pretty good company, embracing the Block Universe concept: Physicists and mathematicians like Einstein, Hermann Weyl, Kurt Godel, and many others. Einstein commented that General Relativity would not have got any father than its long clothes without Minkowski's 4-dimensional continuum of special relativity.

Hi Bob, if you refer to his early comments about GR then that's certainly a misinterpretation of what he meant as he did not want to suggest anything philosophical - quite the contrary as Peterdonis suggested:

"Space is a three-dimensional continuum. [..] the world of physical phenomena which was briefly called "world" by Minkowski is naturally four dimensional in the space-time sense. For it is composed of individual events, each of which is described by four numbers".
See: http://www.bartleby.com/173/17.html

And for a discussion of Paul Davies we have your other thread.

 

[Dale]

Vandam, you are actually in pretty good company, embracing the Block Universe concept: Physicists and mathematicians like Einstein, Hermann Weyl, Kurt Godel, and many others. Einstein commented that General Relativity would not have got any father than its long clothes without Minkowski's 4-dimensional continuum of special relativity.

So what? You can take any position on any topic and compile a similar list of "good company". Particularly if you are willing to take quotes out of context.

 

[Dale]

In that picture the 4-dimensions are all spatial and the 4-D basket just sits in 4-D space while time passes.

That picture is wrong. The signature is -+++, not ++++, so the dimensions are not all spatial.

 

[bobc2]

I had typed up a somewhat lengthy post explaining my interpretation and how it's not compatible with "eternalism".

But luckily had re-read Dalespams post a realized I was merely being opinionated in a physics thread.

bobc2 I do find the Block Universe interpretation fascinating, but philosophically (and from a physics perspective) I don't subscribe.

I am sure you can appreciate the difficulty in conveying such a complex interpretation as "eternalism" in particular via typing it out. You seem to have a deep grasp of the Block Universe Concept and feel strongly about it. Who am I to try and "knock" that, I have no authority on the subject.

So this is all that is left of that "lengthy" post.

Nitsuj, I certainly have no more authority on the subject than you and would be embarrassed to think anyone would think I considered myself to have more access to truth than anyone else here.

Besides, there are experienced physicists around here, whereas I spent only a year or so as a college physics instructor (undergraduate courses only) and since have had a career limited to applied classical physics with no work at all related to special relativity or QM. You've probably been exposed to more relativity topics from your years on the forum than I have (probably less than a year on the forum for me).

In any case these discussions have nothing to do with me, and my personal views are not relevant. I've tried mainly to present concepts expressed by real physicists to help new visitors to the site find a wider range of views that are out there in the physics community. DaleSpam, harrylin and PeterDonis have fairly called me out on the speculative comments, and I need to be more careful there.

 

[Vandam]

4D spacetime consists of events. Events are the buiding blocks, permanantly available to be part of a 'now'world. A 'now' world is your world at a specific point in time.
How one's worldline runs through spacetime determines which events out of total spacetime you will select as being 'simultaneous'. Our 3D world is a construction (made by ourselves) of a limited collection of in spacetime permanently available events. This collection is your world during a split second in your life. In spacetime there are no 'simultaneous' events as such, because 'simultaneity' is something we stick onto the events that we consider happening the same time. Other people will put the simultaneity sticker to oher events.
Whether a world at a specific point in time (= per definition made of simultaneous events) is 'physical' or 'real' is not that important (this gets philosophical), BUT if you consider one world 'real', then all other now worlds of all other 'moving' systems are also to accepted as 'real'. Therefore: all events of spacetime are 'real', or none is 'real'.
Every day I find it mindboggling that this is so difficult to understand by people juggling with Einstein's formulas. Relativity of simultaneous events is so easy, but apparently for many a too great mental step to take...?
I have not read every post of bobc2, but I think bob took that step.