Block Universes

[LizR]

There seems to be a bit of confusion about this idea. Some people on the list seem to abhor the idea of a block universe, but when they attack the concept, they invariably go for straw men, making statements like "change can't happen in a block universe" (which are obviously nonsense, or Einstein et al would hardly have entertained the idea in the first place).

So, I'd like to maybe clarify what the idea means, and give them a proper target if they still want to demolish it.

A block universe is simply one in which time is treated as a dimension. So Newtonian physics, for example, specified a block universe, in which it was believed (e.g. by Laplace) that in principle the past and future could be computed from the state of the present. The Victorians made much of time being the fourth dimension, probably most famously in Wells' "The Time Machine". This was the Newtonian concept of a block universe, and was generally treated quite fatalistically (Wells didn't indicate that history could be changed, for example).

Then special relativity came along and unified space and time into space-time. The reason SR gives rise to a block universe is the relativity of simultaneity. You can slice up space-time in various ways which allow two observers to see the same events occurring in a different order. Hence there is no way to define a "hyperplane of simultaneity" that can be agreed upon by all observers as being a present moment. This indicates that space-time is a four-dimensional arena in which events are embedded. Indeed, I have never heard of an alternative explanation of the relativity of simultaneity that gets around this result - if it's correct, space-time is a block universe, that is to say, time is "just" another dimension.

So classical physics posits a BU. Before worrying about QM, let's see what the classical picture has to say about whether things can change in a block universe. Change is defined as something being different at different times - say the position of the Earth relative to the centre of the galaxy (it traces out a wobbly spiral like a spring as it follows the Sun around an almost circular orbit around the galactic centre every quarter of a billion years). Does the fact that the Earth's orbit is a spiral embedded in space-time prevent the Earth's position from changing? Clearly not. It changes all the time.

The same applies to any other changes that we observe. A person changes as they get older - in the relativistic view these are cross sections through their world-tube (or "lifeline" as Robert Heinlein put it). Particles move through space - they trace out 4 dimensional world lines, but they can still move. Everything we observe takes place in a manner that can be placed within a space-time continuum such that a "god's eye" view (or the relevant equations) would see it as static. But of course we don't see it like that.

This appears to be the source of the problem a few people have with this concept, however - they appear to confuse the god's eye view with ours. But of course we're embedded in space-time - along for the ride. So of course we see change all the time.

QM, perhaps a bit boringly, goes back to the Newtonian view. Space and time are a background arena in which wave functions evolve with time - which is of course a process that can be mapped out within a 4D manifold. Indeed the equations involved are determinstic, and the famous quantum probabilities have to be added "by hand" - so this is rather close to the Newtonian view, apart from the ad hoc wave-function collapses. Fortunately, Everett gave us a completely deterministic view - the wave function evolves in a multiverse - so the block "universe" of QM is instead a block multiverse, but otherwise it is a deterministic process embedded in a space-time manifold.

Lastly, the past is an excellent example of a block universe. It is unchanging, with events embedded in it. If anyone wants to consider what the concept means, think about the past as the example of choice, a 13 billion year long block universe. Change appeared to happen to the people embedded in it, but we have a "god's eye" view of the past, and can see that they were just experiencing different points along their world-tubes. And people in the future will be able to see that the same was true of us.

[Craig Weinberg]

On Saturday, February 1, 2014 2:05:34 AM UTC-5, Liz R wrote:

There seems to be a bit of confusion about this idea. Some people on the list seem to abhor the idea of a block universe, but when they attack the concept, they invariably go for straw men, making statements like "change can't happen in a block universe" (which are obviously nonsense, or Einstein et al would hardly have entertained the idea in the first place).

So, I'd like to maybe clarify what the idea means, and give them a proper target if they still want to demolish it.

A block universe is simply one in which time is treated as a dimension. So Newtonian physics, for example, specified a block universe, in which it was believed (e.g. by Laplace) that in principle the past and future could be computed from the state of the present. The Victorians made much of time being the fourth dimension, probably most famously in Wells' "The Time Machine". This was the Newtonian concept of a block universe, and was generally treated quite fatalistically (Wells didn't indicate that history could be changed, for example).

Then special relativity came along and unified space and time into space-time. The reason SR gives rise to a block universe is the relativity of simultaneity.

The relativity of simultaneity, like the fatalistic Victorian view reveal that the BU makes all change epiphenomenal from the God's Eye perspective. That's ok, but we then have to find a way to meet ourselves halfway and explain why a universe in which change is present at all is even plausible, let alone the kind of intentional change that we seem to find ourselves participating in. The BU makes the physical equations make sense, but it doesn't explain anything about our experience of physics. Just as the relativity of simultaneity makes the absolutely solid-seeming sense of time's uniformity into a local arrangement, the BU makes all change into an unexplained localization and animation of the static block.
 

You can slice up space-time in various ways which allow two observers to see the same events occurring in a different order. Hence there is no way to define a "hyperplane of simultaneity" that can be agreed upon by all observers as being a present moment. This indicates that space-time is a four-dimensional arena in which events are embedded. Indeed, I have never heard of an alternative explanation of the relativity of simultaneity that gets around this result - if it's correct, space-time is a block universe, that is to say, time is "just" another dimension.

Just another dimension does not sit so well with thermodynamic irreversibility.  Could another dimension become irreversible instead. Could a creature exist who can travel backward in time using their feet, but is incapable of making a left turn?

So classical physics posits a BU. Before worrying about QM, let's see what the classical picture has to say about whether things can change in a block universe. Change is defined as something being different at different times - say the position of the Earth relative to the centre of the galaxy (it traces out a wobbly spiral like a spring as it follows the Sun around an almost circular orbit around the galactic centre every quarter of a billion years). Does the fact that the Earth's orbit is a spiral embedded in space-time prevent the Earth's position from changing? Clearly not. It changes all the time.

Clearly from our perspective, which is not the perspective that the BU predicts, as far as I can tell.
 

The same applies to any other changes that we observe. A person changes as they get older - in the relativistic view these are cross sections through their world-tube (or "lifeline" as Robert Heinlein put it). Particles move through space - they trace out 4 dimensional world lines, but they can still move. Everything we observe takes place in a manner that can be placed within a space-time continuum such that a "god's eye" view (or the relevant equations) would see it as static. But of course we don't see it like that.

This appears to be the source of the problem a few people have with this concept, however - they appear to confuse the god's eye view with ours. But of course we're embedded in space-time - along for the ride. So of course we see change all the time.

Why 'of course'? How does the block embed parts of itself in itself? We see change, sure. We are along for the ride. What does the BU say about rides though?
 

QM, perhaps a bit boringly, goes back to the Newtonian view.

Or maybe catastrophically.
 

Space and time are a background arena in which wave functions evolve with time - which is of course a process that can be mapped out within a 4D manifold. Indeed the equations involved are determinstic, and the famous quantum probabilities have to be added "by hand" - so this is rather close to the Newtonian view, apart from the ad hoc wave-function collapses. Fortunately, Everett gave us a completely deterministic view - the wave function evolves in a multiverse - so the block "universe" of QM is instead a block multiverse, but otherwise it is a deterministic process embedded in a space-time manifold.

Isn't the amplituhedron sort of a mini-block? Also there's been that buzz about the universe being a hologram reducible to 2D (+1?). The multiverse and block are last resorts. We reach for them to in desperation when we want to rescue the dream of determinism from the reality of a changing, participatory universe of sensory experience.
 

Lastly, the past is an excellent example of a block universe. It is unchanging, with events embedded in it. If anyone wants to consider what the concept means, think about the past as the example of choice, a 13 billion year long block universe. Change appeared to happen to the people embedded in it, but we have a "god's eye" view of the past, and can see that they were just experiencing different points along their world-tubes. And people in the future will be able to see that the same was true of us.

Even history changes. I have a large wall map of a Victorian timeline that seamlessly flows from its beginning in the Garden of Eden through the Old Testament and into Babylon and Egypt. The God's eye view alters previous God's eye views, which suggests that all views are sensory, and subject to change.

[David Nyman]

On 1 February 2014 07:05, LizR <liz...@gmail.com> wrote:

Everything we observe takes place in a manner that can be placed within a space-time continuum such that a "god's eye" view (or the relevant equations) would see it as static. But of course we don't see it like that.

This appears to be the source of the problem a few people have with this concept, however - they appear to confuse the god's eye view with ours. But of course we're embedded in space-time - along for the ride. So of course we see change all the time.

Hi Liz

I'd just like to be clear that I'm not one of those attacking block (in the sense of co-existent) models in physics or TOEs in general (comp, for example). In fact I'd come to this view already some years back after finally losing confidence in my previous adherence to "presentism" - despite (or rather because of) trying unsuccessfully to defend it against experts. That said, as you may have noticed, I'm rather interested in the heuristics people employ to make intuitive sense of the frog view from within the block, as "Mad Max" Tegmark calls it.

So in that spirit could I ask you to enlarge a little on just what you are thinking about when you use the term "we" in your statements above? Who or what are the "we" who "don't see it like that", "are along for the ride" and "see change all the time"? I'm thinking here specifically of the frog or first-person perspective. Should we think of an "extended frog", for example, that is spread out over a co-existent series of moments, each of which encodes a slightly different spatial-temporal perspective? If so, how specifically can we account for the "momentary frog" that believes itself always to be restricted to only one moment of that series, but is convinced that it's not always the same one? After all, from the frog's perspective, the appearance of an irreversible progression through a series of changes in a singular spatial-temporal location is the most non-negotiable feature of its very life.

If you feel that the best available answer is that it's all an illusion, actually I wouldn't dispute that. But I'm interested in investigating the detailed logic of that very illusion, in approximately the sense that we can investigate and account logically for other illusions like the apparent continuity of vision despite constant rapid ocular saccades. With respect to the latter, we could probably say quite a lot about how the brain contrives that particular illusion  Funnily enough, physicists also tend to appeal loosely to the brain in response to the illusion of the "passage of time" ("it's psychology - not my subject"). But, presumably we can say a little more about what a brain might be doing in deleting the gaps between ocular fixations, whereas we might be a bit in the dark about how "the brain" (itself now conceived as a four-dimensional physical object spread out over time) might contrive to manage the illusion of change in its own apparent spatial-temporal location.

Is a series of frogs spread out over time, each believing it occupies a different spatial-temporal location, equivalent to the apparent experience of one frog occupying a single moment that keeps changing? By what logic do we suppose this would this be distinguishable from the permanently separated experiences of a series of individual frogs? IOW, why wouldn't each of us have the permanent experience of being many different frogs "stuck in time", rather than one frog "moving through time"? These are not intended to be rhetorical questions, by the way. IOW, saying that something is an illusion is only the beginning of an explanation, not the conclusion of one.

Comp may fare better here because it sets out on the path of elucidating exactly how a "we" might be defined such that this "we" might entertain the specific illusion of successive changes in its spatial-temporal location. But for me, at least, this is more difficult to intuit with any precision in a non-comp block concept, precisely because of the under-definition of the referent for "we". The frog perspective is assumed, rather than elucidated. Anyway, as ever, your own thoughts would be much appreciated.

David

[LizR]

Thank you for those kind words :)

The block universe view requires that our sense of time passing emerges from whatever the current state of our brain is, of course. However that requirement isn't limited to the BU view. Any view in which locality is preserved has the same requirement. In fact, presentism, come to think of it, has this requirement even more, because it literally says that the past doesn't exist!

So actually the real problem is how presentism gives rise to the illusion of time passing, with no past there, why s the present constrained to act as though it is there? In a BU the past is there, embedded in space-time, and each state is constrained to follow the last one by the laws of physics. E.g. the state of my brain now can be traced back to the state it was in one second ago, in principle, by following all the atoms involved as they move through space-time.

To answer the question about the frogs. We imagine we are an "extended frog" because of memory; without it we really would be stuck in the present moment, a series of individual isolated moments - and completely unable to function, of course. (If you haven't seen "Memento" do so because it's very good AND it shows the illusion of continuity up very nicely.)

Ironically I don't have any more time to write on this! Later...

[LizR]

Someone asked how a block universe "comes to exist" and if it comes into existence "all at once, or a bit at a time" (or something like that).

I wish I could find the original question, to make sure exactly what it was. But I haven't managed to find it, and I can't spend all night trawling the forum for it, so I will just put my take on the matter here.

Assuming I've got it right, this seems to me a rather odd question. Asking how a block universe comes into existence presupposes that this is a process that must happen within a time stream. This would presumably be external to the 4D manifold, so it would require a 5D "space-time-time" manifold in which to operate. This seems like a crypto-religious viewpoint. The assumption is that a universe has to be created, and even created / sustained at every moment of its existence - rather as Newton imagined God keeping the planets in their orbits (he worked out that they were unstable over the long term, I believe). In this view a 4D space-time can't simply exist due to some logically prior cause. Yet assuming it has to "come into existence" within some external time merely pushes the question back a step - the time within which the BU is created can also be viewed as a BU, with one more time dimension, so one then has to ask how that BU came into existence - and so ad infinitum.

This worked rather nicely in Isaac Asimov's novel "The End of Eternity" (in which he posited a multiverse and an external time running across it, so his "Eternals" could change history and effectively move across the multiverse to a new history in their search for a perfect society). But it seems unnecessary from a scientific viewpoint, and of course runs foul of Occam's razor. It's possible, of course, but there is no evidence for it (and I can't offhand imagine what such evidence would be). It seems to me more sensible to try to explain the existence of space-time by positing something simpler, from which space-time emerges. Most current approaches to quantum gravity use this approach, I believe.

Otherwise, one is just explaining space-time in a circular manner, by requiring the existence of what you're trying to explain - another time dimension - and, in fact, an infinite number of them, if one takes this idea to its logical conclusion ("It's time-tles all the way down...")

[Telmo Menezes]

Hi Liz,

Great avatar :)

On Sun, Feb 2, 2014 at 10:44 AM, LizR <liz...@gmail.com> wrote:
> Someone asked how a block universe "comes to exist" and if it comes into
> existence "all at once, or a bit at a time" (or something like that).
>
> I wish I could find the original question, to make sure exactly what it was.
> But I haven't managed to find it, and I can't spend all night trawling the
> forum for it, so I will just put my take on the matter here.
>
> Assuming I've got it right, this seems to me a rather odd question. Asking
> how a block universe comes into existence presupposes that this is a process
> that must happen within a time stream. This would presumably be external to
> the 4D manifold, so it would require a 5D "space-time-time" manifold in
> which to operate. This seems like a crypto-religious viewpoint. The
> assumption is that a universe has to be created, and even created /
> sustained at every moment of its existence - rather as Newton imagined God
> keeping the planets in their orbits (he worked out that they were unstable
> over the long term, I believe). In this view a 4D space-time can't simply
> exist due to some logically prior cause. Yet assuming it has to "come into
> existence" within some external time merely pushes the question back a step
> - the time within which the BU is created can also be viewed as a BU, with
> one more time dimension, so one then has to ask how that BU came into
> existence - and so ad infinitum.

This is a very good point.

> This worked rather nicely in Isaac Asimov's novel "The End of Eternity" (in
> which he posited a multiverse and an external time running across it, so his
> "Eternals" could change history and effectively move across the multiverse
> to a new history in their search for a perfect society). But it seems
> unnecessary from a scientific viewpoint, and of course runs foul of Occam's
> razor.

Couldn't the same be achieved through quantum suicide, even without
and external timeline?

Cheers,
Telmo.

>It's possible, of course, but there is no evidence for it (and I
> can't offhand imagine what such evidence would be). It seems to me more
> sensible to try to explain the existence of space-time by positing something
> simpler, from which space-time emerges. Most current approaches to quantum
> gravity use this approach, I believe.
>
> Otherwise, one is just explaining space-time in a circular manner, by
> requiring the existence of what you're trying to explain - another time
> dimension - and, in fact, an infinite number of them, if one takes this idea
> to its logical conclusion ("It's time-tles all the way down...")
>

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[David Nyman]

On 2 February 2014 03:42, LizR <liz...@gmail.com> wrote:

To answer the question about the frogs. We imagine we are an "extended frog" because of memory; without it we really would be stuck in the present moment, a series of individual isolated moments - and completely unable to function, of course. (If you haven't seen "Memento" do so because it's very good AND it shows the illusion of continuity up very nicely.)

Ironically I don't have any more time to write on this! Later...

Actually I was lucky enough to see Memento when it was premiered at Sundance in 2001, I think. Great movie.

Yes, I've got the bit about memory - this allows each "momentary frog" to perceive itself as an "extended frog". But now we seem to have conjured up a collection of momentary frogs each one of which imagines itself to be an extended frog with more or less history, if you see what I mean. What I'm interested in is why or how this could resolve into a singular momentary frog that has the impression of one history that keeps extending itself. One can see that this must be true of each of the momentary frogs, each stuck in its pigeon hole, so to speak, but the logic we are discussing seems to imply that each such frog is deluded and that its particular history (memory, that is ) never in fact changes.

The more I think about this the worse it gets. I realise that I can never actually prove that I'm not just one of those momentary frogs stuck in a pigeon hole with my memories of a past history, because that frog could never observe any "transition" to a future moment (i.e. one not yet encoded in its memory) in which that proof would occur. But accepting that "I" am just one such momentary frog seems about as difficult as believing I am not conscious simply because I apparently can't appeal to consciousness to explain why I'm having the thought that I'm conscious (another thread!). I think this is what Hoyle was getting at with his flashlight: we can't seem to help thinking of ourselves successively as one frog at different times. His flashlight idea just pumps the intuition that though we can consider the pigeon holes in any order we like, we can't seem to avoid considering them in some sort of order, even if that order is merely logical, not temporal (because the temporal ordering is already in the pigeon holes themselves).

David

[LizR]

I will come back on this when I have time, but - to continue my suggestions re SF stories - "Flux" by Michael Moorcock addresses the "momentary frog question" rather nicely. Philosophically, at least, it is always possible that we ARE just momentary frogs.

--

[meekerdb]

On 2/2/2014 1:44 AM, LizR wrote:

Someone asked how a block universe "comes to exist" and if it comes into existence "all at once, or a bit at a time" (or something like that).

I wish I could find the original question, to make sure exactly what it was. But I haven't managed to find it, and I can't spend all night trawling the forum for it, so I will just put my take on the matter here.

Assuming I've got it right, this seems to me a rather odd question. Asking how a block universe comes into existence presupposes that this is a process that must happen within a time stream.

I can imagine a semi-block universe in which, as you've often remarked, the past is a block and the universe keeps adding new moments and growing.  This would be like Barbour's time capsules, except just sticking everything into one capsule, like a history book that keeps adding pages.  But yes it implies another exterior "time" in which this "happens"; but then so does Bruno's UD. 

My point is that we needn't take these models seriously.  We just use them to try to picture things.

Brent

[LizR]

I don't think Bruno would agree with that. I think the UD is supposed to function simply by existing, and each state is defined relative to another one....somehow. (But at this point my brain melts...)

My point is that we needn't take these models seriously.  We just use them to try to picture things.

Right.... maybe.... not sure what you mean. That is, I'm not sure where the line is between which models one should take seriously (if any) and which ones are "just for picturing". Did Minkowski take space-time seriously? Does it matter? I thought the important things were prediction of (preferably unexpected) consequences, and being open to refutation.

I assume as we get more into interpretation and general meta-ness, refutation comes to rely more on logical inconsistency or similar meta-refutations. But things can occasionally be "de-meta-ised" as our knowledge improves. This happened for block universes with SR. The experimental evidence for space-time being a 4D manifold is the relativity of simultaneity. I assume that before this, the concept was "just an interpretation" - it was the only picture that made sense of Newtonian physics, but (apart from thought experiments like "Laplace's godlike being") it was not considered experimentally testable. You just had to accept it on logical grounds (or posit extra time streams). Then along came Einstein, and showed that it was experimentally testable after all.

I guess it's possible the MWI will undergo a similar "demetaisation" at some point, perhaps if quantum computers factoring very large numbers become commonplace...

[meekerdb]

That's sort of what is attempted here:

Born in an Infinite Universe: a Cosmological Interpretation of Quantum Mechanics

Anthony Aguirre, Max Tegmark

(Submitted on 5 Aug 2010 (v1), last revised 12 Jun 2012 (this version, v2))

We study the quantum measurement problem in the context of an infinite, statistically uniform space, as could be generated by eternal inflation. It has recently been argued that when identical copies of a quantum measurement system exist, the standard projection operators and Born rule method for calculating probabilities must be supplemented by estimates of relative frequencies of observers. We argue that an infinite space actually renders the Born rule redundant, by physically realizing all outcomes of a quantum measurement in different regions, with relative frequencies given by the square of the wave function amplitudes. Our formal argument hinges on properties of what we term the quantum confusion operator, which projects onto the Hilbert subspace where the Born rule fails, and we comment on its relation to the oft-discussed quantum frequency operator. This analysis unifies the classical and quantum levels of parallel universes that have been discussed in the literature, and has implications for several issues in quantum measurement theory. It also shows how, even for a single measurement, probabilities may be interpreted as relative frequencies in unitary (Everettian) quantum mechanics. We also argue that after discarding a zero-norm part of the wavefunction, the remainder consists of a superposition of indistinguishable terms, so that arguably "collapse" of the wavefunction is irrelevant, and the "many worlds" of Everett's interpretation are unified into one. Finally, the analysis suggests a "cosmological interpretation" of quantum theory in which the wave function describes the actual spatial collection of identical quantum systems, and quantum uncertainty is attributable to the observer's inability to self-locate in this collection.

http://arxiv.org/pdf/1008.1066v2.pdf

Everett's multiple worlds are reified even more than just being projections of the universal state, they are assigned to classically distinct universes.

Brent

[Bruno Marchal]

Only if you call the order of the natiral numlbers a "time". The UD does not use anything more.

Keep in mind that the TOE has been entirely given(*).

My point is that we needn't take these models seriously.  We just use them to try to picture things.

When you say "yes" to the doctor, mechanism is no more used as a metaphor.

It can be false, but that is not yet prove. We don't get contradiction, just quantum weirdness.

Bruno

Brent

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[Kim Jones]

On 3 Feb 2014, at 7:00 pm, Bruno Marchal <mar...@ulb.ac.be> wrote:

I can imagine a semi-block universe in which, as you've often remarked, the past is a block and the universe keeps adding new moments and growing.  This would be like Barbour's time capsules, except just sticking everything into one capsule, like a history book that keeps adding pages.  But yes it implies another exterior "time" in which this "happens"; but then so does Bruno's UD. 

Only if you call the order of the natiral numlbers a "time". The UD does not use anything more.

The UD both generates and executes all programs. In other words it reads the numbers, yes? It both reads the numbers to generate numbers and reads them to execute them. I mean the order of the natural numbers is itself a number isn’t it? Then there are just numbers READING ie glimpsing, looking at, noticing or whatever - each other. What has time got to do with any of that? 

Kim 

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[Bruno Marchal]

On 03 Feb 2014, at 00:35, LizR wrote:

On 3 February 2014 08:03, meekerdb <meek...@verizon.net> wrote:

On 2/2/2014 1:44 AM, LizR wrote:

Someone asked how a block universe "comes to exist" and if it comes into existence "all at once, or a bit at a time" (or something like that).

I wish I could find the original question, to make sure exactly what it was. But I haven't managed to find it, and I can't spend all night trawling the forum for it, so I will just put my take on the matter here.

Assuming I've got it right, this seems to me a rather odd question. Asking how a block universe comes into existence presupposes that this is a process that must happen within a time stream.

I can imagine a semi-block universe in which, as you've often remarked, the past is a block and the universe keeps adding new moments and growing.  This would be like Barbour's time capsules, except just sticking everything into one capsule, like a history book that keeps adding pages.  But yes it implies another exterior "time" in which this "happens"; but then so does Bruno's UD. 

I don't think Bruno would agree with that. I think the UD is supposed to function simply by existing, and each state is defined relative to another one....somehow. (But at this point my brain melts...)

It is not so much that the UD exists, but that the whole UD* exists, or better is emulated, in the "block-time" manner, in arithmetic. 

I will say a little more on this in my reply to Kim.

Bruno

My point is that we needn't take these models seriously.  We just use them to try to picture things.

Right.... maybe.... not sure what you mean. That is, I'm not sure where the line is between which models one should take seriously (if any) and which ones are "just for picturing". Did Minkowski take space-time seriously? Does it matter? I thought the important things were prediction of (preferably unexpected) consequences, and being open to refutation.

I assume as we get more into interpretation and general meta-ness, refutation comes to rely more on logical inconsistency or similar meta-refutations. But things can occasionally be "de-meta-ised" as our knowledge improves. This happened for block universes with SR. The experimental evidence for space-time being a 4D manifold is the relativity of simultaneity. I assume that before this, the concept was "just an interpretation" - it was the only picture that made sense of Newtonian physics, but (apart from thought experiments like "Laplace's godlike being") it was not considered experimentally testable. You just had to accept it on logical grounds (or posit extra time streams). Then along came Einstein, and showed that it was experimentally testable after all.

I guess it's possible the MWI will undergo a similar "demetaisation" at some point, perhaps if quantum computers factoring very large numbers become commonplace...

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[Bruno Marchal]

On 03 Feb 2014, at 12:09, Kim Jones wrote:

On 3 Feb 2014, at 7:00 pm, Bruno Marchal <mar...@ulb.ac.be> wrote:

I can imagine a semi-block universe in which, as you've often remarked, the past is a block and the universe keeps adding new moments and growing.  This would be like Barbour's time capsules, except just sticking everything into one capsule, like a history book that keeps adding pages.  But yes it implies another exterior "time" in which this "happens"; but then so does Bruno's UD. 

Only if you call the order of the natiral numlbers a "time". The UD does not use anything more.

The UD both generates and executes all programs.

OK.

In other words it reads the numbers, yes?

I am not sure what you mean. 

It both reads the numbers to generate numbers

In the language Prolog, you can easily write a program which generates the numbers, and accessorily is also a statement in predicate logic:  (:= is the same as "<-", or "only if")

Number(0)

Number(S(x)) := Number(x)

You just type this on your computer, when it executes a Prolog interpreter,  and then you type

Number(x)? print(x)

Then the prolog interpreter generates, without stopping

0

S(0)

S(S(0))

S(S(S(0)))

S(S(S(S(0))))

S(S(S(S(S(0)))))

S(S(S(S(S(S(0))))))

S(S(S(S(S(S(S(0)))))))

S(S(S(S(S(S(S(S(0))))))))

S(S(S(S(S(S(S(S(S(0)))))))))

S(S(S(S(S(S(S(S(S(S(0))))))))))

S(S(S(S(S(S(S(S(S(S(S(0)))))))))))

S(S(S(S(S(S(S(S(S(S(S(S(0))))))))))))

...

By typing CTRL-Q, fortunately, you can stop the prolog interpreter, so that you can do something else.

We could also not have written "print(x)". In that case the prolog interpreter would still generate the numbers, but without printing it on the screen. Such a program does not compute a function, it generates a set. Thinking in term of the phi_i, I would say that such a program has no output, even when it prints his finding of objects satisfying the axioms given.

I am not sure he read numbers. It is asked if it exists x such that number(x), by the "?", and as he believes number(0), he find quickly an example. Then the second axiom is verified for x = 0:  "number(S(0)) := number(0). And so by modus ponens, knowing number(0), it concludes that number(S(0)), and find another solution S(0), and he get the next numbers by applying, again and again, the modus ponens rule.

and reads them to execute them. I mean the order of the natural numbers is itself a number isn’t it?

Somehow Plotinus asked the same question!

Well, in this case, the order is not a number per se. The usual mathematical content of the order "<" of the natural number s is the infinite set {(0, 1), (0, 2), (1, 2), (0, 3), (1, 2), (1, 3), (0, 4), ... } (the set of all (x, y) such that x < y. It is an infinite set. But it is computable, so there is a number o "order" so that phi_o(x,y) = 1 if x < y and 0 else. The order (the infinite set) is a number, like you are a machine. It is only in virtue of being represented by a universal machine/numbers.

Then there are just numbers READING ie glimpsing, looking at, noticing or whatever - each other. What has time got to do with any of that? 

OK. So a universal dovetailer does not just generate the numbers, it executes them on each of them.

It generates all i, i = 0, 1, 2, 3, ... (or 0, s(0), etc... depending of its language), but it generates also all the P_i, that is the programs, ordered lexicographically, in some language (may be its own language, that is not important), and it computes all phi_i, that is generates the one step dynamical computation of P_i(j), for all i and j.

Now, arithmetic itself is Turing universal, so that all this is done in he "block-possible-activities-of-the-universal-numbers" which is basically the sigma_1 complete part of arithmetical truth. 

Computation is a dynamical notion, but its dynamic is digital and entirely defined by some natural number order. 

You can always refer to the nth step of the computation of this or that machine, done by the UD, or to the nth step of the UD itself.  It just happen that such a dynamical notion, a bit like F= Ma, has a complete "block-universe" depiction in a tiny and effective (sem-decidable, partial computable) part of the atemporal arithmetical reality, the realm which satisfies propositions like 2+2=4 or Fermat theorem.

What did you mean by "reading numbers"?

Bruno

Kim 

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http://iridia.ulb.ac.be/~marchal/

[Kim Jones]

On 4 Feb 2014, at 3:34 am, Bruno Marchal <mar...@ulb.ac.be> wrote:

What did you mean by "reading numbers”?

I imagine the UD as a kind of ‘playhead’ or ‘read head’ in a digital device that scans encoded information. The difference of course being that there is no output. The lack of output is correlated with the ‘block time’ concept somehow.

The Prolog interpreter demo you gave suggests the algorithms are ‘generated’ but I am suggesting they already exist (“everything exists”) and are merely scanned or read by the Universal Song Pointer Line which is at all positions simultaneously and, presumably, eternally (whatever ‘eternally’ could possibly mean in a block universe.) 

K

[ghi...@gmail.com]

Hi Liz, thanks for doing this thread, the history metaphor  was also a great help. I wasn't clear what block time was and now I've got a better idea.

 

I remember reading someone argue against it in terms of energy, and I think this was thrown out by others with explanations, but can't remember any details.  Any chance you could me by the explanation of that?

 

I was also able to get a good beginner foothold understanding of your explanation how SR gives rise to blocktime via relativity of simultaneity. Best I can I do see the implication is compelling and hard to avoid - I can't think of any criticism directly. But then I wouldn't expect to be able to do that from the level I am at.

 

But more generically speaking, would this inference for blocktime sit at the edge of relativity or at its core. What I mean is, beyond that it is an implication of relativity, have there been or are there any prospects for developing blocktime as it arises from relativity to such point, predictions get made? Or any other kind of reinforcement? Or does blocktime go on to imply something beyond blocktime?

 

If not then out of interest, what sort of strength would you personally attach to blocktime? Say compared to the speed of light, or big bang? Genuinelly curious.

 

The intuitive problem I would have with blocktime would veiry much be along the same themes as a lot of other inferences in one way or another at the 'edge'. The same assumption seems to come into play, that nature has infinite resources at her fingertips...is able to get those resources pretty much anywhere she likes too. Which might be true, but I return to that worry that, whether true or not, the explanation is always available to us, and will always deliver this kind of resolution, regardless of context. So long as the problem is at the edge of knowledge.

 

Is that a worry for you as well?

 

 

 

 

 

 

[LizR]

On 4 February 2014 11:48, <ghi...@gmail.com> wrote:

Hi Liz, thanks for doing this thread, the history metaphor  was also a great help. I wasn't clear what block time was and now I've got a better idea.

Good, that was the point. A lot of people seemed to be attacking it on the basis of straw man arguments, so obviously not everyone "gets" it.

 

I remember reading someone argue against it in terms of energy, and I think this was thrown out by others with explanations, but can't remember any details.  Any chance you could me by the explanation of that?

I do remember that, but only very vaguely - so I can't really say what the problem or resolution was. Sorry. If anyone can remember, please let me know.

(Maybe it was something similar to the fallacy that the MWI violates conservation of energy because it's constantly "creating new universes" ... ?)

 

I was also able to get a good beginner foothold understanding of your explanation how SR gives rise to blocktime via relativity of simultaneity. Best I can I do see the implication is compelling and hard to avoid - I can't think of any criticism directly. But then I wouldn't expect to be able to do that from the level I am at.

I haven't been able to come up with anything. Of course any type of physics that treats time as a dimension implies block time, for example Newtonian mechanics does, as illustrated by Laplace's comment about an omniscient being that could know the past and future given the configuration of the universe at a single moment.

 

But more generically speaking, would this inference for blocktime sit at the edge of relativity or at its core. What I mean is, beyond that it is an implication of relativity, have there been or are there any prospects for developing blocktime as it arises from relativity to such point, predictions get made? Or any other kind of reinforcement? Or does blocktime go on to imply something beyond blocktime?

The idea of space-time seems to be central to SR, and even more so to GR. (It was also central to Newtonian physics, but as "space and time" which taken together have the features of a block universe.)

 

If not then out of interest, what sort of strength would you personally attach to blocktime? Say compared to the speed of light, or big bang? Genuinelly curious.

I'm not sure what you mean about the speed of light. I'd say block time is the best interpretation of what phyics is telling us about the universe because (a) the theoretical and experimental evidence is very strong and (b) the ontological basis for it is good - it's the minimal explanation necessary. Although other variants like "presentism" are theoretically possible, they're unnecessary to explain all existing observations, and only push the problem of time back a step, since presentism just says there's an extra time dimension in which our universe is being continually created and destroyed - but of course another time dimension can also be viewed as a block universe, one step removed. If that time dimension is also given a time dimension in which it's happening, that can also be viewed as a block universe, 2 steps removed ... and so on.

 

The intuitive problem I would have with blocktime would veiry much be along the same themes as a lot of other inferences in one way or another at the 'edge'. The same assumption seems to come into play, that nature has infinite resources at her fingertips...is able to get those resources pretty much anywhere she likes too. Which might be true, but I return to that worry that, whether true or not, the explanation is always available to us, and will always deliver this kind of resolution, regardless of context. So long as the problem is at the edge of knowledge.

 

Is that a worry for you as well?

It might be for some things, but block time has been so uncontentious amongst the vast majority of physicists since Newton that I don't have any problems with it. It's been very well thought through by many minds, and no one has come up with a viable alternative that I'm aware of.

[David Nyman]

On 2 February 2014 18:53, LizR <liz...@gmail.com> wrote:

I will come back on this when I have time

Thanks.

 

but - to continue my suggestions re SF stories - "Flux" by Michael Moorcock addresses the "momentary frog question" rather nicely. Philosophically, at least, it is always possible that we ARE just momentary frogs.

I can't seem to locate a reasonably priced copy of this. You would be doing me a most tremendous favour if you could precise the relevant bits?

Actually, I've had the glimmer of an idea. It's not fully worked out, but I'll just dump what I have. When Mad Max talks about the bird view, the assumption is that it's a panoptic (god's eye) view that encompasses all the momentary frogs together. IOW, all the frog perspectives are available "simultaneously" from this extrinsic perspective. When he talks about the frog view, it's natural to think of the focus as collapsing right down to that of a single momentary frog. But perhaps we should rather think of the frog focus as continuing to be fundamentally panoptic (i.e. encompassing all the frog perspectives) except that "down there" the extrinsic simultaneity is intrinsically broken by the discrete perspective of each momentary frog. If so, one could then see Hoyle's heuristic as a frog's eye view of the experiential consequences of this broken simultaneity.

David 

[Jesse Mazer]

On Mon, Feb 3, 2014 at 5:48 PM, <ghi...@gmail.com> wrote:

 

But more generically speaking, would this inference for blocktime sit at the edge of relativity or at its core. What I mean is, beyond that it is an implication of relativity, have there been or are there any prospects for developing blocktime as it arises from relativity to such point, predictions get made? Or any other kind of reinforcement? Or does blocktime go on to imply something beyond blocktime?

If "block time" is taken as a definite ontological statement about all times "existing" in exactly the same sense, rather than just referring to the idea of treating time as a dimension conceptually or in our mathematical models, then I think it's a metaphysical postulate that goes beyond anything directly implied by relativity. Relativity says that all frames, with their different definitions of simultaneity, are on equal footing as far as the laws of physics are concerned, but it doesn't deal with ontology. If someone proposes that one frame's definition of simultaneity is "metaphysically preferred" in the sense it defines the "true present", but adds the caveat that this frame is not in any way physically preferred so that no conceivable experiment could determine which frame it is, this wouldn't contradict the physics. It would be an "interpretation" of SR, similar to the different "interpretations" of QM which postulate different things about ontology (the real existence of other worlds in the MWI, or a single world with hidden variables in Bohmian mechanics, for example) but are indistinguishable experimentally. 

That said, if you subscribe to any form of Occam's razor or even a criteria of "elegance" when it comes to choosing between different metaphysical hypotheses, it seems a lot simpler to assume that there is no metaphysically preferred definition of simultaneity, just as I think many would agree the MWI is the simplest way of interpreting the physical theory of QM. Adding extra "purely metaphysical" entities to a theory, which don't correspond to anything that appears in the mathematical formalism of the theory itself (which would apply to things like a "true present" or to hidden variables in QM), seems a bit like postulating that there are invisible intangible elves sitting on each person's head which have no causal effects on anything we can measure; sure it's logically possible, but it seems like a very inelegant and arbitrary way for reality to work.

Jesse

[LizR]

I will try to precis Flux at some point - in the meantime, here are a few comments ("Flux" was written in 1963, by Moorcock and Barrington Bayley - my favourite fantasy and SF writers, respectively).

`Flux' is a sardonic retelling of the H. G. Wells classic tale `The Time Machine'. In a near-future European Union facing economic and social collapse, the multi-skilled genius Max File is sent 10 years into the future to try and divine where things went wrong, and how calamity may be prevented. Unfortunately time travel is a tricky business, and Max soon finds himself going farther in space and time than he ever expected....

-----------

When the government of the European Economic Community has no idea what to do next, they send Marshall-in-Chief Max File ten years into the future to find out the eventual effects of their actions.

Although this story was too abstract for my taste, I did enjoy the early presentation of what today might be called a Boltzmann Brain. [Apr 2012]

 The world from which he had come, or any other world for that matter, could dissipate into its component elements at any instant, or could have come into being at any previous instant, complete with everybody’s memories! 

--------------------------

Here is a review...

http://www.graemesfantasybookreview.com/2010/07/flux-michael-moorcockbarrington-bayley_07.html

[LizR]

On 4 February 2014 12:23, Jesse Mazer <laser...@gmail.com> wrote:

On Mon, Feb 3, 2014 at 5:48 PM, <ghi...@gmail.com> wrote:

 

But more generically speaking, would this inference for blocktime sit at the edge of relativity or at its core. What I mean is, beyond that it is an implication of relativity, have there been or are there any prospects for developing blocktime as it arises from relativity to such point, predictions get made? Or any other kind of reinforcement? Or does blocktime go on to imply something beyond blocktime?

If "block time" is taken as a definite ontological statement about all times "existing" in exactly the same sense, rather than just referring to the idea of treating time as a dimension conceptually or in our mathematical models, then I think it's a metaphysical postulate that goes beyond anything directly implied by relativity. Relativity says that all frames, with their different definitions of simultaneity, are on equal footing as far as the laws of physics are concerned, but it doesn't deal with ontology. If someone proposes that one frame's definition of simultaneity is "metaphysically preferred" in the sense it defines the "true present", but adds the caveat that this frame is not in any way physically preferred so that no conceivable experiment could determine which frame it is, this wouldn't contradict the physics. It would be an "interpretation" of SR, similar to the different "interpretations" of QM which postulate different things about ontology (the real existence of other worlds in the MWI, or a single world with hidden variables in Bohmian mechanics, for example) but are indistinguishable experimentally. 

SR directly demonstrates block time via the relativity of simultaneity. This can be tested experimentally.

That said, if you subscribe to any form of Occam's razor or even a criteria of "elegance" when it comes to choosing between different metaphysical hypotheses, it seems a lot simpler to assume that there is no metaphysically preferred definition of simultaneity, just as I think many would agree the MWI is the simplest way of interpreting the physical theory of QM. Adding extra "purely metaphysical" entities to a theory, which don't correspond to anything that appears in the mathematical formalism of the theory itself (which would apply to things like a "true present" or to hidden variables in QM), seems a bit like postulating that there are invisible intangible elves sitting on each person's head which have no causal effects on anything we can measure; sure it's logically possible, but it seems like a very inelegant and arbitrary way for reality to work.

The MWI is deterministic, however, and hence has hidden variables.

[David Nyman]

Ta very much :)

[Edgar L. Owen]

Liz,

You keep repeating your UNSUBSTANTIATED claim that both Newton and Einstein believed in block time.

I've repeatedly asked you to substantiate this claim with some actual quotes from them but you have been unable to do so.

Please provide quotes substantiating this or withdraw the claim. That's only fair...

Edgar

[LizR]

On 4 February 2014 12:44, Edgar L. Owen <edga...@att.net> wrote:

Liz,

You keep repeating your UNSUBSTANTIATED claim that both Newton and Einstein believed in block time.

It isn't a question of belief. Newtonian and Einsteinian machanics both imply the existence of a block universe.

I've repeatedly asked you to substantiate this claim with some actual quotes from them but you have been unable to do so.

Please provide quotes substantiating this or withdraw the claim. That's only fair...

Obviously Newton didn't use that phrase. Equally obviously it's implied by his equations, as Laplace realised.

http://en.wikipedia.org/wiki/Laplace%27s_demon

We may regard the present state of the universe as the effect of its past and the cause of its future. An intellect which at a certain moment would know all forces that set nature in motion, and all positions of all items of which nature is composed, if this intellect were also vast enough to submit these data to analysis, it would embrace in a single formula the movements of the greatest bodies of the universe and those of the tiniest atom; for such an intellect nothing would be uncertain and the future just like the past would be present before its eyes.

—Pierre Simon Laplace, A Philosophical Essay on Probabilities^[3]

Einstein's equations shows that space-time is a 4D manifold, as Minkowski pointed out. His "canonical" quote on this is:

 The views of space and time which I wish to lay before you have sprung from the soil of experimental physics, and therein lies their strength. They are radical. Henceforth space by itself, and time by itself, are doomed to fade away into mere shadows, and only a kind of union of the two will preserve an independent reality.

 

— Hermann Minkowski

Otherwise, just read papers on the subject of SR. It isn't a secret that SR treats space-time as a 4D manifold.

Here is an introduction to the subject:

 

http://www.phy.syr.edu/courses/modules/LIGHTCONE/minkowski.html

[Jesse Mazer]

On Mon, Feb 3, 2014 at 6:29 PM, LizR <liz...@gmail.com> wrote:

On 4 February 2014 12:23, Jesse Mazer <laser...@gmail.com> wrote:

On Mon, Feb 3, 2014 at 5:48 PM, <ghi...@gmail.com> wrote:

 

But more generically speaking, would this inference for blocktime sit at the edge of relativity or at its core. What I mean is, beyond that it is an implication of relativity, have there been or are there any prospects for developing blocktime as it arises from relativity to such point, predictions get made? Or any other kind of reinforcement? Or does blocktime go on to imply something beyond blocktime?

If "block time" is taken as a definite ontological statement about all times "existing" in exactly the same sense, rather than just referring to the idea of treating time as a dimension conceptually or in our mathematical models, then I think it's a metaphysical postulate that goes beyond anything directly implied by relativity. Relativity says that all frames, with their different definitions of simultaneity, are on equal footing as far as the laws of physics are concerned, but it doesn't deal with ontology. If someone proposes that one frame's definition of simultaneity is "metaphysically preferred" in the sense it defines the "true present", but adds the caveat that this frame is not in any way physically preferred so that no conceivable experiment could determine which frame it is, this wouldn't contradict the physics. It would be an "interpretation" of SR, similar to the different "interpretations" of QM which postulate different things about ontology (the real existence of other worlds in the MWI, or a single world with hidden variables in Bohmian mechanics, for example) but are indistinguishable experimentally. 

SR directly demonstrates block time via the relativity of simultaneity. This can be tested experimentally.

The relativity of simultaneity is a claim about physics, not metaphysics. Specifically, it's a claim that the laws of physics work exactly the same in all inertial frames, which have different definitions of simultaneity. If someone agrees that no frame's definition of simultaneity is "preferred" in any physical sense, but that one is "metaphysically preferred" in a way that is wholly invisible to all possible experiments, this would not contradict SR or the relativity of simultaneity as a physical principle.

 

That said, if you subscribe to any form of Occam's razor or even a criteria of "elegance" when it comes to choosing between different metaphysical hypotheses, it seems a lot simpler to assume that there is no metaphysically preferred definition of simultaneity, just as I think many would agree the MWI is the simplest way of interpreting the physical theory of QM. Adding extra "purely metaphysical" entities to a theory, which don't correspond to anything that appears in the mathematical formalism of the theory itself (which would apply to things like a "true present" or to hidden variables in QM), seems a bit like postulating that there are invisible intangible elves sitting on each person's head which have no causal effects on anything we can measure; sure it's logically possible, but it seems like a very inelegant and arbitrary way for reality to work.

The MWI is deterministic, however, and hence has hidden variables.

No. The Schroedinger equation which calculates wavefunction evolution in QM is already fully deterministic, the MWI just dispenses with the extra postulate of "wavefunction collapse" on measurement, which is the only random element in QM. Determinism only implies hidden variables if you assume each experiment has a *unique* outcome, and that this outcome is generated in a deterministic way by the initial conditions. If you assume that the physical state at the end of an experiment is a quantum state that's a superposition of many possible classical results, then this can be calculated from a prior quantum state using just the standard Schroedinger equation.

Jesse

[Jesse Mazer]

On Mon, Feb 3, 2014 at 6:44 PM, Edgar L. Owen <edga...@att.net> wrote:

Liz,

You keep repeating your UNSUBSTANTIATED claim that both Newton and Einstein believed in block time.

I've repeatedly asked you to substantiate this claim with some actual quotes from them but you have been unable to do so.

Please provide quotes substantiating this or withdraw the claim. That's only fair...

In Einstein's case this does definitely seem to be his own belief, for example when his lifelong friend Michael Besso died in 1955, he sent his family a letter in which he wrote:

"Now he has departed from this strange world a little ahead of me. That means nothing. People like us, who believe in physics, know that the distinction between past, present, and future is only a stubbornly persistent illusion."

I think the serious context of this letter likely precludes the possibility that he was joking, or that he was just speaking in an offhand way about how relativity models the world as opposed to expressing a belief about the way the world really is.

Jesse

[Edgar L. Owen]

Liz, Liz, Liz!

OK, now you ADMIT that neither Newton or Einstein believed in block time. Thanks!

Your claim that their theories imply (thanks for using the soft imply rather than prove) block time is just your erroneous interpretation in an attempt to lend weight to your own belief.

Your use of the Laplace quote to corroborate that is wonderful since if you actually read it Laplace specifically mentions "the PRESENT STATE of the universe" indicating that Laplace accepts a present moment like nearly everyone on earth does. That's a direct REFUTATION of belief in block time by Laplace himself!

So your quote actually proves the exact OPPOSITE of what you claim it does.

The fact that time is a 4th dimension does NOT either require or imply block time. Everyone and everything is always at only ONE place in time exactly the same as they are always at ONE place in space. That one place is the present moment. True the past is a 4th dimension but we do NOT LIVE in the past. We live in the present. We exist in the present, not in the past nor the future. 

That's the correct understanding of the 4-dimensional universe and I'm pretty sure both Newton and Einstein understood this....

Block time requires that everything is at MULTIPLE points in time from when its created to when it vanishes.

Relativity does NOT require nor imply block time. In fact when the fact that everything continually travels through spacetime at the speed of light is taken into account relativity FALSIFIES block time because that requires everything to be at one and only one position in time, and that means that there is a present moment for everything. And this is directly confirmable through observation, the exact same kind and status of observation that all science is based upon.

It really couldn't be any simpler... 

Edgar

[LizR]

On 4 February 2014 13:32, Jesse Mazer <laser...@gmail.com> wrote:

On Mon, Feb 3, 2014 at 6:29 PM, LizR <liz...@gmail.com> wrote:

SR directly demonstrates block time via the relativity of simultaneity. This can be tested experimentally.

The relativity of simultaneity is a claim about physics, not metaphysics. Specifically, it's a claim that the laws of physics work exactly the same in all inertial frames, which have different definitions of simultaneity. If someone agrees that no frame's definition of simultaneity is "preferred" in any physical sense, but that one is "metaphysically preferred" in a way that is wholly invisible to all possible experiments, this would not contradict SR or the relativity of simultaneity as a physical principle.

OK, maybe what I should have said is that no one has come up with an explanation for the ROS that doesn't include the concept of space-time being a 4D manifold.
I'm not sure if that leaves us with a physical or metaphysical problem (or maybe no problem at all!)

That said, if you subscribe to any form of Occam's razor or even a criteria of "elegance" when it comes to choosing between different metaphysical hypotheses, it seems a lot simpler to assume that there is no metaphysically preferred definition of simultaneity, just as I think many would agree the MWI is the simplest way of interpreting the physical theory of QM. Adding extra "purely metaphysical" entities to a theory, which don't correspond to anything that appears in the mathematical formalism of the theory itself (which would apply to things like a "true present" or to hidden variables in QM), seems a bit like postulating that there are invisible intangible elves sitting on each person's head which have no causal effects on anything we can measure; sure it's logically possible, but it seems like a very inelegant and arbitrary way for reality to work.

The MWI is deterministic, however, and hence has hidden variables.

No. The Schroedinger equation which calculates wavefunction evolution in QM is already fully deterministic, the MWI just dispenses with the extra postulate of "wavefunction collapse" on measurement, which is the only random element in QM. Determinism only implies hidden variables if you assume each experiment has a *unique* outcome, and that this outcome is generated in a deterministic way by the initial conditions. If you assume that the physical state at the end of an experiment is a quantum state that's a superposition of many possible classical results, then this can be calculated from a prior quantum state using just the standard Schroedinger equation.

Well, yes, of course. The MWI is defined as QM with no collapse, and the SWE is deterministic, therefore we have realism....don't we? OK, I may have used the wrong terminology here. Maybe "hidden variables" means something different from what I thought. I assumed the MWI, being completely deterministic (a "block multiverse") had a definite state at all times, and that therefore there is stuff that we can't measure but is there, even so - which I thought meant hidden variables. But I may have messed up.

(That said, time symmetry could also be termed hidden variables, I think?)

[LizR]

Oh dear, you really don't have a clue, do you? OK, that's it. I foolishly replied to one or two of your posts in the hope you'd magically grown up, but I can't be bothered with this level of willful ignorance and infantile nonsense. I'll let you get on with scoring imaginary points, and stick with people who have something meaningful to say.

[Edgar L. Owen]

Jesse,

That's possible but it's only one quote and considering the circumstances it could have just been an attempt to provide comfort to the grieving family. Also Einstein is known to have spoken metaphorically at times and even to seemingly contradict himself on occasion (eg. on religious belief), so I think one would need to have more than just that one quote to make a convincing case.

On the other hand I suspect one can find very many Einstein quotes in which he mentions the PRESENT which would stand in direct contradiction to a belief in a block universe. Don't you agree?

Edgar

[Edgar L. Owen]

Liz,

Talk about confirmation bias! It's SOP when a person can't come up with a real objective scientific rebuttal to an argument that they just flame and retreat. How awful it would be if facts and rational arguments changed their belief system! Goodness gracious, can't let that happen...

:-)

Edgar

[Jesse Mazer]

On Mon, Feb 3, 2014 at 8:28 PM, Edgar L. Owen <edga...@att.net> wrote:

Jesse,

That's possible but it's only one quote and considering the circumstances it could have just been an attempt to provide comfort to the grieving family. Also Einstein is known to have spoken metaphorically at times and even to seemingly contradict himself on occasion (eg. on religious belief), so I think one would need to have more than just that one quote to make a convincing case.

All of his statements on religion I've seen seem completely consistent with a Spinoza-esque pantheism, where do you think he contradicted himself on religion? As for block time, that wasn't his only comment in support of the idea, for example at http://everythingforever.com/einstein.htm we find the following even more explicit endorsement of the block time view: 

'Since there exists in this four dimensional structure [space-time] no longer any sections which represent "now" objectively, the concepts of happening and becoming are indeed not completely suspended, but yet complicated. It appears therefore more natural to think of physical reality as a four dimensional existence, instead of, as hitherto, the evolution of a three dimensional existence.'

 

On the other hand I suspect one can find very many Einstein quotes in which he mentions the PRESENT which would stand in direct contradiction to a belief in a block universe.

Did he use it in the context of talking about the nature of time in physics or philosophy, or was he just using it in the ordinary everyday way, like talking about the "present political situation" or something? If the latter, I think eternalists talk that way all the time, simultaneity issues make no practical difference when you're just talking about events confined to the Earth. And aside from simultaneity issues, talking about the "present" doesn't preclude the possibility that other times are equally real, it's just an indexical term like "here".

Jesse

 

 

On Monday, February 3, 2014 7:37:44 PM UTC-5, jessem wrote:

On Mon, Feb 3, 2014 at 6:44 PM, Edgar L. Owen <edga...@att.net> wrote:

Liz,

You keep repeating your UNSUBSTANTIATED claim that both Newton and Einstein believed in block time.

I've repeatedly asked you to substantiate this claim with some actual quotes from them but you have been unable to do so.

Please provide quotes substantiating this or withdraw the claim. That's only fair...

In Einstein's case this does definitely seem to be his own belief, for example when his lifelong friend Michael Besso died in 1955, he sent his family a letter in which he wrote:

"Now he has departed from this strange world a little ahead of me. That means nothing. People like us, who believe in physics, know that the distinction between past, present, and future is only a stubbornly persistent illusion."

I think the serious context of this letter likely precludes the possibility that he was joking, or that he was just speaking in an offhand way about how relativity models the world as opposed to expressing a belief about the way the world really is.

Jesse

--

[LizR]

By the way, I just came across this rather amusing illustration of how SR leads to block space-time:

http://en.wikipedia.org/wiki/Rietdijk-Putnam_argument

[ghi...@gmail.com]

Thanks for all that. Very interesting. So what sort of implications would block time have for individual lives. Do they happen only onetime while their time is being actively blocked in? Or does blocktime exist statically as the end-to-end story of the universe? 

 

I appreciate the construction is the chain of relations, but does anyone say whether the relations necessarily happen like a domino effect from the big bang through, just the one time? Or can they get washed through like waves of an incoming tide? is another version of me happening on the wave just behind the one I'm on?

 

I think what I'm realty asking is what is blocktime giving the world? It's giving us a deeper vision of reality (if true). But if it is objectively true, what purpose or utility does it serve, if any?

 

My experience when I ask something like that is normally puzzlement..."what do you mean what purpose/utility?' It's an implication of relativity! :o)

 

But it's strange really. Where are knowledge is strongest, at the core of our own universe, there is no part of it that does not serve a fundamental purpose in the workings of physical law. If someone asked what purpose were served by neutrinos, or dark matter, or gamma rays, gravity....there would be several interpretations involving some utility in the scheme of things.

 

But what happens at the edges..of our theories, of our knowledge, is completely different. And tightly linked to what action we take. This one here is in the same class as what takes place with QM. An interpretation. Both times then, MWI and this time, the result is an - albeit completely differently configured - sort of translation even from a set of relations in one universe, to the same relations distributed in a multiverse-like construction.

 

Obviously we don't see this as a multiverse in that blocktime happens along the passage of time we associate with this single universe. But relative to the old concept of a single version of objects moving through the passage of time, blocktime is a multiverse-like construction IMHO.

 

Guess what we're getting could be objective , or it could be an artefact of doing something improper, brought about by circumstances involving invoking a process of interpretation of some sense of an exposed edge of a theory.

 

Two possibilities

 

[Jesse Mazer]

On Mon, Feb 3, 2014 at 8:40 PM, Edgar L. Owen <edga...@att.net> wrote:

Liz,

Talk about confirmation bias! It's SOP when a person can't come up with a real objective scientific rebuttal to an argument that they just flame and retreat. How awful it would be if facts and rational arguments changed their belief system! Goodness gracious, can't let that happen...

:-)

Speaking of simply retreating when one can't come up with a scientific rebuttal in order to avoid having one's beliefs challenged by rational argument, do you ever plan to respond to the following 3 posts of mine?

1. The one at https://groups.google.com/d/msg/everything-list/HeLo1QmdHFQ/4pDpJ6WXYgkJ where I pointed out that when the matter field is more irregular than the "perfect fluid" of the FLRW model, there is no obvious "natural" way to divide up 4D spacetime into a series of 3D slice, since there's no longer a unique choice of slicings that ensures the matter field on each slice is perfectly homogenous...so as I asked, what criteria would you propose to use to decide which of various possible slicings represents p-time? Or would you admit that you have no idea what physical criteria, if any, could choose between competing simultaneity conventions in a universe where matter isn't distributed in a perfectly homogenous way?

2. The one at https://groups.google.com/d/msg/everything-list/HeLo1QmdHFQ/Mw8jXkmytGoJ where I continued with the analogy to 2D geometry, and pointed out that the same logic you seem to be using to get the conclusion of a truth about which events happened at the "same point in time" independent of coordinate system could equally well be used to argue for a truth about which points on different roads were at the "same point in y" independent of a particular choice of x and y axes, which seems obviously silly...but as I said, "If you agree it's silly in the 2D case, then you still need to explain what the relevant difference is that does *not* lead you to conclude there must be such an objective truth about common y-values, even though every step of the argument up until then maps perfectly onto your own argument about time."

3. The one at https://groups.google.com/d/msg/everything-list/HeLo1QmdHFQ/eZSEOw-ilXUJ where I asked if you were asserting there's just one point on an observer's worldline that represents his "actual local time", or if you just meant that each point on an observer's worldline has its own definition of the "local time" without presupposing that only one of those points could be "correct". As I pointed out, if you are *assuming* the former at the start of your argument, then your entire argument is merely an exercise in circular reasoning, since idea of a privileged point on each object's worldline that is happening at the "present moment" is precisely what you were trying to demonstrate, so you can't just assume it from the start.

 

Jesse

[ghi...@gmail.com]

On Monday, February 3, 2014 11:29:11 PM UTC, Liz R wrote:

On 4 February 2014 12:23, Jesse Mazer <laser...@gmail.com> wrote:

On Mon, Feb 3, 2014 at 5:48 PM, <ghi...@gmail.com> wrote:

 

But more generically speaking, would this inference for blocktime sit at the edge of relativity or at its core. What I mean is, beyond that it is an implication of relativity, have there been or are there any prospects for developing blocktime as it arises from relativity to such point, predictions get made? Or any other kind of reinforcement? Or does blocktime go on to imply something beyond blocktime?

If "block time" is taken as a definite ontological statement about all times "existing" in exactly the same sense, rather than just referring to the idea of treating time as a dimension conceptually or in our mathematical models, then I think it's a metaphysical postulate that goes beyond anything directly implied by relativity. Relativity says that all frames, with their different definitions of simultaneity, are on equal footing as far as the laws of physics are concerned, but it doesn't deal with ontology. If someone proposes that one frame's definition of simultaneity is "metaphysically preferred" in the sense it defines the "true present", but adds the caveat that this frame is not in any way physically preferred so that no conceivable experiment could determine which frame it is, this wouldn't contradict the physics. It would be an "interpretation" of SR, similar to the different "interpretations" of QM which postulate different things about ontology (the real existence of other worlds in the MWI, or a single world with hidden variables in Bohmian mechanics, for example) but are indistinguishable experimentally. 

SR directly demonstrates block time via the relativity of simultaneity. This can be tested experimentally.

 

Liz, do you say above:

 

- blocktime can be tested experimentally

 

- relativity of simultaneity can be tested experimentally and blocktime is inferred from relativity simultaneity

[ghi...@gmail.com]

On Tuesday, February 4, 2014 12:19:42 AM UTC, Liz R wrote:

On 4 February 2014 12:44, Edgar L. Owen <edga...@att.net> wrote:

Liz,

You keep repeating your UNSUBSTANTIATED claim that both Newton and Einstein believed in block time.

It isn't a question of belief. Newtonian and Einsteinian machanics both imply the existence of a block universe.

 

How does it derive from the Newtonian picture? I don't seem to get the visualization ...can ye help :O) 

I've repeatedly asked you to substantiate this claim with some actual quotes from them but you have been unable to do so.

Please provide quotes substantiating this or withdraw the claim. That's only fair...

Obviously Newton didn't use that phrase. Equally obviously it's implied by his equations, as Laplace realised.

http://en.wikipedia.org/wiki/Laplace%27s_demon

We may regard the present state of the universe as the effect of its past and the cause of its future. An intellect which at a certain moment would know all forces that set nature in motion, and all positions of all items of which nature is composed, if this intellect were also vast enough to submit these data to analysis, it would embrace in a single formula the movements of the greatest bodies of the universe and those of the tiniest atom; for such an intellect nothing would be uncertain and the future just like the past would be present before its eyes.

—Pierre Simon Laplace, A Philosophical Essay on Probabilities^[3]

 

Liz - are you saying then, that cause and effect implies blocktime, or do I get that wrong?

[Jesse Mazer]

On Mon, Feb 3, 2014 at 7:55 PM, LizR <liz...@gmail.com> wrote:

On 4 February 2014 13:32, Jesse Mazer <laser...@gmail.com> wrote:

On Mon, Feb 3, 2014 at 6:29 PM, LizR <liz...@gmail.com> wrote:

SR directly demonstrates block time via the relativity of simultaneity. This can be tested experimentally.

The relativity of simultaneity is a claim about physics, not metaphysics. Specifically, it's a claim that the laws of physics work exactly the same in all inertial frames, which have different definitions of simultaneity. If someone agrees that no frame's definition of simultaneity is "preferred" in any physical sense, but that one is "metaphysically preferred" in a way that is wholly invisible to all possible experiments, this would not contradict SR or the relativity of simultaneity as a physical principle.

OK, maybe what I should have said is that no one has come up with an explanation for the ROS that doesn't include the concept of space-time being a 4D manifold.

What do you mean by "explanation" for ROS, though? It's normally assumed that the fundamental laws of physics have various symmetries, like rotational invariance and CPT-symmetry, and the ROS is just a consequence of Lorentz-symmetry. Do we need a meta-explanation for why the laws of physics have any particular symmetries? I suppose here on this list we do play around with the possibility that the laws of physics themselves could be derived from some more basic assumptions, but physicists normally take fundamental laws as a stopping point that can't be explained in terms of anything more basic (unless they turn out to not be "fundamental" laws after all). 

And when you say the "concept of space-time being a 4D manifold", again I think you have to distinguish between the idea that it's useful to *model* it in that way from some more ontological statement that all points on the manifold "exist" in the same sense. While modern physics certainly models spacetime in that way, again I don't see how physics can lead you to any definite ontological claims, though those of us who favor Occam's razor might say that the fact that there's no physically preferred definition of simultaneity makes it seem more "natural" to assume there's no metaphysically preferred simultaneity either.

 

I'm not sure if that leaves us with a physical or metaphysical problem (or maybe no problem at all!)

That said, if you subscribe to any form of Occam's razor or even a criteria of "elegance" when it comes to choosing between different metaphysical hypotheses, it seems a lot simpler to assume that there is no metaphysically preferred definition of simultaneity, just as I think many would agree the MWI is the simplest way of interpreting the physical theory of QM. Adding extra "purely metaphysical" entities to a theory, which don't correspond to anything that appears in the mathematical formalism of the theory itself (which would apply to things like a "true present" or to hidden variables in QM), seems a bit like postulating that there are invisible intangible elves sitting on each person's head which have no causal effects on anything we can measure; sure it's logically possible, but it seems like a very inelegant and arbitrary way for reality to work.

The MWI is deterministic, however, and hence has hidden variables.

No. The Schroedinger equation which calculates wavefunction evolution in QM is already fully deterministic, the MWI just dispenses with the extra postulate of "wavefunction collapse" on measurement, which is the only random element in QM. Determinism only implies hidden variables if you assume each experiment has a *unique* outcome, and that this outcome is generated in a deterministic way by the initial conditions. If you assume that the physical state at the end of an experiment is a quantum state that's a superposition of many possible classical results, then this can be calculated from a prior quantum state using just the standard Schroedinger equation.

Well, yes, of course. The MWI is defined as QM with no collapse, and the SWE is deterministic, therefore we have realism....don't we? OK, I may have used the wrong terminology here. Maybe "hidden variables" means something different from what I thought. I assumed the MWI, being completely deterministic (a "block multiverse") had a definite state at all times, and that therefore there is stuff that we can't measure but is there, even so - which I thought meant hidden variables. But I may have messed up.

(That said, time symmetry could also be termed hidden variables, I think?)

As I said in my comment to you at http://www.mail-archive.com/everyth...@googlegroups.com/msg46130.html I think there are various conceivable ways a theory could be time-symmetric--the conventional one is just that you can use the same equations to "retrodict" a system's earlier state as you used to predict its later state, given some set of conditions at a particular time, and I don't see how that could be said to involve hidden variables. But the other type of possible time-symmetric theory I discussed in that post, where to determine physical states at a given point in spacetime you must take into account both its future and its past, might perhaps be said to involve a sort of hidden variable since we don't have direct knowledge of the future events that may be influencing things in the here and now.

[meekerdb]

On 2/3/2014 7:56 PM, ghi...@gmail.com wrote:
> I think what I'm realty asking is what is blocktime giving the world? It's giving us a
> deeper vision of reality (if true). But if it is objectively true, what purpose or
> utility does it serve, if any?

It's a model. It gives us a picture to think about and helps us apply the mathematics.
And it serves that purpose, our purpose, whether it's true or not.

> My experience when I ask something like that is normally puzzlement..."what do you mean
> what purpose/utility?' It's an implication of relativity! :o)
> But it's strange really. Where are knowledge is strongest, at the core of our own
> universe, there is no part of it that does not serve a fundamental purpose in the
> workings of physical law.

We invent the physical laws to describe the universe. Since we try to be complete,
naturally we try to include every part we know about. In any case, at the core of our own
universe there's is a black hole - and we don't know how a black hole works. GR says you
can fall thru the event horizon and not ever notice it. AMPS theory says you'll be
destroyed by intense radiation. And neither one of them can explain how unitarity is not
violated.

> If someone asked what purpose were served by neutrinos, or dark matter, or gamma rays,
> gravity....there would be several interpretations involving some utility in the scheme
> of things.

There would? What does it mean for gamma rays to have utility?

Brent

[ghi...@gmail.com]

Liz - I was just thinking. If Newton's world predicted a variant of blocktime. What is that saying, given Newton's world wasn't correct? Or was it based some aspect that is correct?

 

But is the sense that blocktime comes out of newton's world, compatible with relativity? Are both legitimate equivalent representations of the same consistent thing? Or is the Newton in fact no longer thought correct.

 

What does it mean if something that isn't correct gets blocktime? Is that strengthening the case for blocktime or raising a doubt that it is objectively real, given it arises as an artefact of the same kind of interpretative activity on an edge of a theory?

 

Just wondering. 

[meekerdb]

On 2/3/2014 8:29 PM, ghi...@gmail.com wrote:
> Liz - I was just thinking. If Newton's world predicted a variant of blocktime. What is
> that saying, given Newton's world wasn't correct? Or was it based some aspect that is
> correct?
> But is the sense that blocktime comes out of newton's world, compatible with
> relativity? Are both legitimate equivalent representations of the same consistent thing?
> Or is the Newton in fact no longer thought correct.

The block universe just means taking space+time to be a 4D manifold so that every point is
labelled by four numbers that are smooth functions. It can be used to picture Newtonian
dynamics, special relativity, general relativity, and other theories. It's just a way of
designating events (t,x,y,z).

> What does it mean if something that isn't correct gets blocktime?

There's no problem with false things implying true ones; in fact falsehoods imply everything.

> Is that strengthening the case for blocktime or raising a doubt that it is objectively
> real, given it arises as an artefact of the same kind of interpretative activity on an
> edge of a theory?

Is it objectively real that we can label every point on the Earth's surface with a
latitude and longitude?

Brent

[ghi...@gmail.com]

I had been assuming blocktime was sort of hard linked to relativity of simultaneity in relativity in some sort of 1:1 unique pairing.

 

But in fact it's a general idea for a representation

 

Which we decide at some point the better explanation for reality.

 

So do you think block time is what is inferred as a reality by each of these  space and time variants?

 

 

 

[meekerdb]

On 2/3/2014 9:41 PM, ghi...@gmail.com wrote:

So do you think block time is what is inferred as a reality by each of these  space and time variants?

You mean "implied by"?  It doesn't imply anything about which is right, because it applies equally to all of them, just like we could label every point with a latitude and longitude on a torodial Earth. 

Brent

[LizR]

On 4 February 2014 16:56, <ghi...@gmail.com> wrote:

Thanks for all that. Very interesting. So what sort of implications would block time have for individual lives. Do they happen only onetime while their time is being actively blocked in? Or does blocktime exist statically as the end-to-end story of the universe? 

Block time doesn't have any implications for individual lives. It can't make a difference to everyday life, because obviously it predicts that everyday life will be exactly what we observe it to be (otherwise it could be shown to be false). It would seem that the 4D space-time manifold "exists as the story of the universe".

 

I appreciate the construction is the chain of relations, but does anyone say whether the relations necessarily happen like a domino effect from the big bang through, just the one time? Or can they get washed through like waves of an incoming tide? is another version of me happening on the wave just behind the one I'm on?

This interesting possibility is explored in Barrington Bayley's novel "Collision with Chronos" which I heartily recommend even though as far as we know it doesn't have anything to do with real physics!

For things to wash through block time you need an extra time stream. So you move your block universe out to 5D - 3 space and 2 time dimensions. There's no reason to posit this to explain any observed phenomenon. A 4D space-time manifold appears to be sufficient.

 

I think what I'm realty asking is what is blocktime giving the world? It's giving us a deeper vision of reality (if true). But if it is objectively true, what purpose or utility does it serve, if any?

My experience when I ask something like that is normally puzzlement..."what do you mean what purpose/utility?' It's an implication of relativity! :o)

Well, it's more an ontological underpinning of relativity, since the whole thing is based around the concept that the universe is a 4D manifold (a warped one in GR). So I guess the puzzlement is similar to if you'd asked "what is the purpose/utility of the big bang, or of evolution?" It sounds like a theological / teleological question.

 

But it's strange really. Where are knowledge is strongest, at the core of our own universe, there is no part of it that does not serve a fundamental purpose in the workings of physical law. If someone asked what purpose were served by neutrinos, or dark matter, or gamma rays, gravity....there would be several interpretations involving some utility in the scheme of things.

 

But what happens at the edges..of our theories, of our knowledge, is completely different. And tightly linked to what action we take. This one here is in the same class as what takes place with QM. An interpretation. Both times then, MWI and this time, the result is an - albeit completely differently configured - sort of translation even from a set of relations in one universe, to the same relations distributed in a multiverse-like construction.

It isn't really an interpretation, except insofar as all physics could be called that (I think "model" would be a better term). It's one of the entities postulated by SR and GR, much as (say) mass is.  I suppose it has the benefit of being the only view of time that actually makes sense - at least, I've never seen a physical theory that explains time any other way, and it's hard to imagine any other way of explaining it - although presentism expands the scope of the block universe to extra time dimensions, but I don't consider that a good thing.

 

Obviously we don't see this as a multiverse in that blocktime happens along the passage of time we associate with this single universe. But relative to the old concept of a single version of objects moving through the passage of time, blocktime is a multiverse-like construction IMHO.

QM posits a block multiverse. 

 

Guess what we're getting could be objective , or it could be an artefact of doing something improper, brought about by circumstances involving invoking a process of interpretation of some sense of an exposed edge of a theory.

Any idea what? 

 

Two possibilities

Only one of them has had amazing predictive success, however :-)

[LizR]

On 4 February 2014 17:06, <ghi...@gmail.com> wrote:

On Monday, February 3, 2014 11:29:11 PM UTC, Liz R wrote:

On 4 February 2014 12:23, Jesse Mazer <laser...@gmail.com> wrote:

On Mon, Feb 3, 2014 at 5:48 PM, <ghi...@gmail.com> wrote:

 

But more generically speaking, would this inference for blocktime sit at the edge of relativity or at its core. What I mean is, beyond that it is an implication of relativity, have there been or are there any prospects for developing blocktime as it arises from relativity to such point, predictions get made? Or any other kind of reinforcement? Or does blocktime go on to imply something beyond blocktime?

If "block time" is taken as a definite ontological statement about all times "existing" in exactly the same sense, rather than just referring to the idea of treating time as a dimension conceptually or in our mathematical models, then I think it's a metaphysical postulate that goes beyond anything directly implied by relativity. Relativity says that all frames, with their different definitions of simultaneity, are on equal footing as far as the laws of physics are concerned, but it doesn't deal with ontology. If someone proposes that one frame's definition of simultaneity is "metaphysically preferred" in the sense it defines the "true present", but adds the caveat that this frame is not in any way physically preferred so that no conceivable experiment could determine which frame it is, this wouldn't contradict the physics. It would be an "interpretation" of SR, similar to the different "interpretations" of QM which postulate different things about ontology (the real existence of other worlds in the MWI, or a single world with hidden variables in Bohmian mechanics, for example) but are indistinguishable experimentally. 

SR directly demonstrates block time via the relativity of simultaneity. This can be tested experimentally.

 

Liz, do you say above:

 

- blocktime can be tested experimentally

 

- relativity of simultaneity can be tested experimentally and blocktime is inferred from relativity simultaneity

The latter. (However, as an integral part of SR block time is as experimentally verified as other consequences - Fitzgerald contraction and time dilation, for example.)

[LizR]

On 4 February 2014 17:11, <ghi...@gmail.com> wrote:

On Tuesday, February 4, 2014 12:19:42 AM UTC, Liz R wrote:

On 4 February 2014 12:44, Edgar L. Owen <edga...@att.net> wrote:

Liz,

You keep repeating your UNSUBSTANTIATED claim that both Newton and Einstein believed in block time.

It isn't a question of belief. Newtonian and Einsteinian machanics both imply the existence of a block universe.

 

How does it derive from the Newtonian picture? I don't seem to get the visualization ...can ye help :O) 

Newton treated time as a dimension in which the positions of particles changed smoothly under applied forces. Treating time as a dimension is (by definition) block time.

I've repeatedly asked you to substantiate this claim with some actual quotes from them but you have been unable to do so.

Please provide quotes substantiating this or withdraw the claim. That's only fair...

Obviously Newton didn't use that phrase. Equally obviously it's implied by his equations, as Laplace realised.

http://en.wikipedia.org/wiki/Laplace%27s_demon

We may regard the present state of the universe as the effect of its past and the cause of its future. An intellect which at a certain moment would know all forces that set nature in motion, and all positions of all items of which nature is composed, if this intellect were also vast enough to submit these data to analysis, it would embrace in a single formula the movements of the greatest bodies of the universe and those of the tiniest atom; for such an intellect nothing would be uncertain and the future just like the past would be present before its eyes.

—Pierre Simon Laplace, A Philosophical Essay on Probabilities^[3]

 

Liz - are you saying then, that cause and effect implies blocktime, or do I get that wrong?

The "clockwork universe" view implied that the positions of all its constituents at all times can be calculated. This is equivalent to a picture of a static 4D structure.

However, Newton's mechanics only imply a block universe (actually it was apparently Galileo who originally came up with this worldview).

Einstein made it explicit.

[LizR]

On 4 February 2014 17:29, <ghi...@gmail.com> wrote:

Liz - I was just thinking. If Newton's world predicted a variant of blocktime. What is that saying, given Newton's world wasn't correct? Or was it based some aspect that is correct?

Well it clearly doesn't disprove that space and time form a 4D manifold! Newtonian mechanics are a very good approximation to relativistic ones for velocities well below light speed. Similarly, a block universe with space and time separate is a good approximation to a 4D space-time manifold when velocities are well below c. 

 

What does it mean if something that isn't correct gets blocktime? Is that strengthening the case for blocktime or raising a doubt that it is objectively real, given it arises as an artefact of the same kind of interpretative activity on an edge of a theory?

It isn't on the edge of the theory. It's central to SR. 

[LizR]

As Brent says we have to bear in mind that SR is a model of reality. The ontological status of its components is another question, as it is with every theory. Most physicists have assumed that either space-time really is a 4D manifold (Max Tegmark for instance), or it's something else that is very well modelled by one. The truth is most likely the latter, but that it's emergent from something simpler - LQG, CDT, M-theory, comp, and so on all assume "something simpler". Whatever it emerges from probably won't have space or time dimensions (which will make it even more problematic to worry about the possibility that it isn't "all there eternally" - or however you'd like to characterise a block universe!)

[Bruno Marchal]

On 03 Feb 2014, at 22:33, Kim Jones wrote:

On 4 Feb 2014, at 3:34 am, Bruno Marchal <mar...@ulb.ac.be> wrote:

What did you mean by "reading numbers”?

I imagine the UD as a kind of ‘playhead’ or ‘read head’ in a digital device that scans encoded information. The difference of course being that there is no output. The lack of output is correlated with the ‘block time’ concept somehow.

OK, but there is no inputs too. If the UD is written in the form of a Turing machine, the rubber is empty at the start.

The Prolog interpreter demo you gave suggests the algorithms are ‘generated’ but I am suggesting they already exist (“everything exists”)

Yes, but that would make the talk confusing. If something is generated by the algorithm in due course, it does not need to be presented to the algorithm. No input, really means, in computer science, that the Turing machine is given an empty rubber. 

There are always bit of convention, given that input/output is a relative notion, but that is why we like (in computer science) to be locally very specific (just to prevent possible misunderstandings).

and are merely scanned or read by the Universal Song Pointer Line which is at all positions simultaneously and, presumably, eternally (whatever ‘eternally’ could possibly mean in a block universe.) 

Eternally can mean two things here. True in all space-time regions in the block multiverse, or atemporal, like the whole block multiverse itself.

Bruno

K

============================

Kim Jones B.Mus.GDTL

Email:     kimj...@ozemail.com.au
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[Bruno Marchal]

On 04 Feb 2014, at 00:12, David Nyman wrote:

On 2 February 2014 18:53, LizR <liz...@gmail.com> wrote:

I will come back on this when I have time

Thanks.

 

but - to continue my suggestions re SF stories - "Flux" by Michael Moorcock addresses the "momentary frog question" rather nicely. Philosophically, at least, it is always possible that we ARE just momentary frogs.

I can't seem to locate a reasonably priced copy of this. You would be doing me a most tremendous favour if you could precise the relevant bits?

Actually, I've had the glimmer of an idea. It's not fully worked out, but I'll just dump what I have. When Mad Max talks about the bird view, the assumption is that it's a panoptic (god's eye) view that encompasses all the momentary frogs together. IOW, all the frog perspectives are available "simultaneously" from this extrinsic perspective. When he talks about the frog view, it's natural to think of the focus as collapsing right down to that of a single momentary frog.

But somehow, that is what we have to do, if we want to trust the doctor, who will really captured such "frog view", in the 3p sense.

Of course, you are right that the content, 3p and 1p, of that "view" is related with many other "frog view", even all in some sense (that is why we talk on UD and block universe, the FPI, etc.).

But perhaps we should rather think of the frog focus as continuing to be fundamentally panoptic (i.e. encompassing all the frog perspectives) except that "down there" the extrinsic simultaneity is intrinsically broken by the discrete perspective of each momentary frog. If so, one could then see Hoyle's heuristic as a frog's eye view of the experiential consequences of this broken simultaneity.

I think that is is what happen when we apply the theaeteus definition on provability, except that provability is already a symmetry broker, then the Theaetetus makes it even more assymetrical (irreflexive, even), and the miracle is more in the fact that, defining the physical reality from that move, we get the core symmetry back. I hope I will be able to clarify this for you with the self-reference (modal) logics.

Bruno

David 

On 3 February 2014 03:19, David Nyman <da...@davidnyman.com> wrote:

On 2 February 2014 03:42, LizR <liz...@gmail.com> wrote:

To answer the question about the frogs. We imagine we are an "extended frog" because of memory; without it we really would be stuck in the present moment, a series of individual isolated moments - and completely unable to function, of course. (If you haven't seen "Memento" do so because it's very good AND it shows the illusion of continuity up very nicely.)

Ironically I don't have any more time to write on this! Later...

Actually I was lucky enough to see Memento when it was premiered at Sundance in 2001, I think. Great movie.

Yes, I've got the bit about memory - this allows each "momentary frog" to perceive itself as an "extended frog". But now we seem to have conjured up a collection of momentary frogs each one of which imagines itself to be an extended frog with more or less history, if you see what I mean. What I'm interested in is why or how this could resolve into a singular momentary frog that has the impression of one history that keeps extending itself. One can see that this must be true of each of the momentary frogs, each stuck in its pigeon hole, so to speak, but the logic we are discussing seems to imply that each such frog is deluded and that its particular history (memory, that is ) never in fact changes.

The more I think about this the worse it gets. I realise that I can never actually prove that I'm not just one of those momentary frogs stuck in a pigeon hole with my memories of a past history, because that frog could never observe any "transition" to a future moment (i.e. one not yet encoded in its memory) in which that proof would occur. But accepting that "I" am just one such momentary frog seems about as difficult as believing I am not conscious simply because I apparently can't appeal to consciousness to explain why I'm having the thought that I'm conscious (another thread!). I think this is what Hoyle was getting at with his flashlight: we can't seem to help thinking of ourselves successively as one frog at different times. His flashlight idea just pumps the intuition that though we can consider the pigeon holes in any order we like, we can't seem to avoid considering them in some sort of order, even if that order is merely logical, not temporal (because the temporal ordering is already in the pigeon holes themselves).

David

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[Bruno Marchal]

On 04 Feb 2014, at 00:23, Jesse Mazer wrote:

On Mon, Feb 3, 2014 at 5:48 PM, <ghi...@gmail.com> wrote:

 

But more generically speaking, would this inference for blocktime sit at the edge of relativity or at its core. What I mean is, beyond that it is an implication of relativity, have there been or are there any prospects for developing blocktime as it arises from relativity to such point, predictions get made? Or any other kind of reinforcement? Or does blocktime go on to imply something beyond blocktime?

If "block time" is taken as a definite ontological statement about all times "existing" in exactly the same sense, rather than just referring to the idea of treating time as a dimension conceptually or in our mathematical models, then I think it's a metaphysical postulate that goes beyond anything directly implied by relativity. Relativity says that all frames, with their different definitions of simultaneity, are on equal footing as far as the laws of physics are concerned, but it doesn't deal with ontology. If someone proposes that one frame's definition of simultaneity is "metaphysically preferred" in the sense it defines the "true present", but adds the caveat that this frame is not in any way physically preferred so that no conceivable experiment could determine which frame it is, this wouldn't contradict the physics. It would be an "interpretation" of SR, similar to the different "interpretations" of QM which postulate different things about ontology (the real existence of other worlds in the MWI, or a single world with hidden variables in Bohmian mechanics, for example) but are indistinguishable experimentally. 

That said, if you subscribe to any form of Occam's razor or even a criteria of "elegance" when it comes to choosing between different metaphysical hypotheses, it seems a lot simpler to assume that there is no metaphysically preferred definition of simultaneity, just as I think many would agree the MWI is the simplest way of interpreting the physical theory of QM. Adding extra "purely metaphysical" entities to a theory, which don't correspond to anything that appears in the mathematical formalism of the theory itself (which would apply to things like a "true present" or to hidden variables in QM), seems a bit like postulating that there are invisible intangible elves sitting on each person's head which have no causal effects on anything we can measure; sure it's logically possible, but it seems like a very inelegant and arbitrary way for reality to work.

I agree. That is what I refer to the usual occam razor.  With comp, the physical PRIMITIVE reality becomes of that kind. Totally useless, even to explain the physical appearances. 

Bruno

Jesse

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[Bruno Marchal]

On 04 Feb 2014, at 00:29, LizR wrote:

On 4 February 2014 12:23, Jesse Mazer <laser...@gmail.com> wrote:

On Mon, Feb 3, 2014 at 5:48 PM, <ghi...@gmail.com> wrote:

 

But more generically speaking, would this inference for blocktime sit at the edge of relativity or at its core. What I mean is, beyond that it is an implication of relativity, have there been or are there any prospects for developing blocktime as it arises from relativity to such point, predictions get made? Or any other kind of reinforcement? Or does blocktime go on to imply something beyond blocktime?

If "block time" is taken as a definite ontological statement about all times "existing" in exactly the same sense, rather than just referring to the idea of treating time as a dimension conceptually or in our mathematical models, then I think it's a metaphysical postulate that goes beyond anything directly implied by relativity. Relativity says that all frames, with their different definitions of simultaneity, are on equal footing as far as the laws of physics are concerned, but it doesn't deal with ontology. If someone proposes that one frame's definition of simultaneity is "metaphysically preferred" in the sense it defines the "true present", but adds the caveat that this frame is not in any way physically preferred so that no conceivable experiment could determine which frame it is, this wouldn't contradict the physics. It would be an "interpretation" of SR, similar to the different "interpretations" of QM which postulate different things about ontology (the real existence of other worlds in the MWI, or a single world with hidden variables in Bohmian mechanics, for example) but are indistinguishable experimentally. 

SR directly demonstrates block time via the relativity of simultaneity. This can be tested experimentally.

That said, if you subscribe to any form of Occam's razor or even a criteria of "elegance" when it comes to choosing between different metaphysical hypotheses, it seems a lot simpler to assume that there is no metaphysically preferred definition of simultaneity, just as I think many would agree the MWI is the simplest way of interpreting the physical theory of QM. Adding extra "purely metaphysical" entities to a theory, which don't correspond to anything that appears in the mathematical formalism of the theory itself (which would apply to things like a "true present" or to hidden variables in QM), seems a bit like postulating that there are invisible intangible elves sitting on each person's head which have no causal effects on anything we can measure; sure it's logically possible, but it seems like a very inelegant and arbitrary way for reality to work.

The MWI is deterministic, however, and hence has hidden variables.

But not "hidden variable" in the EPR sense. In the MWI, there are hidden universes, they are not variable, but terms in the universal wave, and we just don't know which terms apply to us. If it was hidden variable in the EPR sense, then by Bell, they would be non-local, and you would conclude falsely (like Clark) that the MWI has to be non local (which I doubt very much).

Bruno

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[Bruno Marchal]

On 04 Feb 2014, at 00:44, Edgar L. Owen wrote:

Liz,

You keep repeating your UNSUBSTANTIATED claim that both Newton and Einstein believed in block time.

You might read the book by Pale Yourgrau on "Einstein and Gödel". Einstein never believed in time, and definietly stop to believe in its possibility after contemplating Gödel's solution of GR with time loops.

I don't know for Newton, as its metaphysics is rather messy and complex, but Pascal is close to the block-universe idea, which is sleepy in all deterministic account of reality.

You have not answered my question of "can we share the same p-time, in case we can slow down our brain?"

Bruno

I've repeatedly asked you to substantiate this claim with some actual quotes from them but you have been unable to do so.

Please provide quotes substantiating this or withdraw the claim. That's only fair...

Edgar

On Monday, February 3, 2014 6:11:18 PM UTC-5, Liz R wrote:

On 4 February 2014 11:48, <ghi...@gmail.com> wrote:

Hi Liz, thanks for doing this thread, the history metaphor  was also a great help. I wasn't clear what block time was and now I've got a better idea.

Good, that was the point. A lot of people seemed to be attacking it on the basis of straw man arguments, so obviously not everyone "gets" it.

 

I remember reading someone argue against it in terms of energy, and I think this was thrown out by others with explanations, but can't remember any details.  Any chance you could me by the explanation of that?

I do remember that, but only very vaguely - so I can't really say what the problem or resolution was. Sorry. If anyone can remember, please let me know.

(Maybe it was something similar to the fallacy that the MWI violates conservation of energy because it's constantly "creating new universes" ... ?)

 

I was also able to get a good beginner foothold understanding of your explanation how SR gives rise to blocktime via relativity of simultaneity. Best I can I do see the implication is compelling and hard to avoid - I can't think of any criticism directly. But then I wouldn't expect to be able to do that from the level I am at.

I haven't been able to come up with anything. Of course any type of physics that treats time as a dimension implies block time, for example Newtonian mechanics does, as illustrated by Laplace's comment about an omniscient being that could know the past and future given the configuration of the universe at a single moment.

But more generically speaking, would this inference for blocktime sit at the edge of relativity or at its core. What I mean is, beyond that it is an implication of relativity, have there been or are there any prospects for developing blocktime as it arises from relativity to such point, predictions get made? Or any other kind of reinforcement? Or does blocktime go on to imply something beyond blocktime?

The idea of space-time seems to be central to SR, and even more so to GR. (It was also central to Newtonian physics, but as "space and time" which taken together have the features of a block universe.)

 

If not then out of interest, what sort of strength would you personally attach to blocktime? Say compared to the speed of light, or big bang? Genuinelly curious.

I'm not sure what you mean about the speed of light. I'd say block time is the best interpretation of what phyics is telling us about the universe because (a) the theoretical and experimental evidence is very strong and (b) the ontological basis for it is good - it's the minimal explanation necessary. Although other variants like "presentism" are theoretically possible, they're unnecessary to explain all existing observations, and only push the problem of time back a step, since presentism just says there's an extra time dimension in which our universe is being continually created and destroyed - but of course another time dimension can also be viewed as a block universe, one step removed. If that time dimension is also given a time dimension in which it's happening, that can also be viewed as a block universe, 2 steps removed ... and so on.

 

The intuitive problem I would have with blocktime would veiry much be along the same themes as a lot of other inferences in one way or another at the 'edge'. The same assumption seems to come into play, that nature has infinite resources at her fingertips...is able to get those resources pretty much anywhere she likes too. Which might be true, but I return to that worry that, whether true or not, the explanation is always available to us, and will always deliver this kind of resolution, regardless of context. So long as the problem is at the edge of knowledge.

 

Is that a worry for you as well?

It might be for some things, but block time has been so uncontentious amongst the vast majority of physicists since Newton that I don't have any problems with it. It's been very well thought through by many minds, and no one has come up with a viable alternative that I'm aware of.

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[Bruno Marchal]

On 04 Feb 2014, at 01:19, LizR wrote:

On 4 February 2014 12:44, Edgar L. Owen <edga...@att.net> wrote:

Liz,

You keep repeating your UNSUBSTANTIATED claim that both Newton and Einstein believed in block time.

It isn't a question of belief. Newtonian and Einsteinian machanics both imply the existence of a block universe.

I've repeatedly asked you to substantiate this claim with some actual quotes from them but you have been unable to do so.

Please provide quotes substantiating this or withdraw the claim. That's only fair...

Obviously Newton didn't use that phrase. Equally obviously it's implied by his equations, as Laplace realised.

Yes, I was thinking of Laplace. Why did I wrote Pascal?

Bruno

http://en.wikipedia.org/wiki/Laplace%27s_demon

We may regard the present state of the universe as the effect of its past and the cause of its future. An intellect which at a certain moment would know all forces that set nature in motion, and all positions of all items of which nature is composed, if this intellect were also vast enough to submit these data to analysis, it would embrace in a single formula the movements of the greatest bodies of the universe and those of the tiniest atom; for such an intellect nothing would be uncertain and the future just like the past would be present before its eyes.

—Pierre Simon Laplace, A Philosophical Essay on Probabilities^[3]

Einstein's equations shows that space-time is a 4D manifold, as Minkowski pointed out. His "canonical" quote on this is:

 The views of space and time which I wish to lay before you have sprung from the soil of experimental physics, and therein lies their strength. They are radical. Henceforth space by itself, and time by itself, are doomed to fade away into mere shadows, and only a kind of union of the two will preserve an independent reality.

 

— Hermann Minkowski

Otherwise, just read papers on the subject of SR. It isn't a secret that SR treats space-time as a 4D manifold.

Here is an introduction to the subject:

 

http://www.phy.syr.edu/courses/modules/LIGHTCONE/minkowski.html

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[Bruno Marchal]

On 04 Feb 2014, at 01:55, LizR wrote:

On 4 February 2014 13:32, Jesse Mazer <laser...@gmail.com> wrote:

On Mon, Feb 3, 2014 at 6:29 PM, LizR <liz...@gmail.com> wrote:

SR directly demonstrates block time via the relativity of simultaneity. This can be tested experimentally.

The relativity of simultaneity is a claim about physics, not metaphysics. Specifically, it's a claim that the laws of physics work exactly the same in all inertial frames, which have different definitions of simultaneity. If someone agrees that no frame's definition of simultaneity is "preferred" in any physical sense, but that one is "metaphysically preferred" in a way that is wholly invisible to all possible experiments, this would not contradict SR or the relativity of simultaneity as a physical principle.

OK, maybe what I should have said is that no one has come up with an explanation for the ROS that doesn't include the concept of space-time being a 4D manifold.

I'm not sure if that leaves us with a physical or metaphysical problem (or maybe no problem at all!)

That said, if you subscribe to any form of Occam's razor or even a criteria of "elegance" when it comes to choosing between different metaphysical hypotheses, it seems a lot simpler to assume that there is no metaphysically preferred definition of simultaneity, just as I think many would agree the MWI is the simplest way of interpreting the physical theory of QM. Adding extra "purely metaphysical" entities to a theory, which don't correspond to anything that appears in the mathematical formalism of the theory itself (which would apply to things like a "true present" or to hidden variables in QM), seems a bit like postulating that there are invisible intangible elves sitting on each person's head which have no causal effects on anything we can measure; sure it's logically possible, but it seems like a very inelegant and arbitrary way for reality to work.

The MWI is deterministic, however, and hence has hidden variables.

No. The Schroedinger equation which calculates wavefunction evolution in QM is already fully deterministic, the MWI just dispenses with the extra postulate of "wavefunction collapse" on measurement, which is the only random element in QM. Determinism only implies hidden variables if you assume each experiment has a *unique* outcome, and that this outcome is generated in a deterministic way by the initial conditions. If you assume that the physical state at the end of an experiment is a quantum state that's a superposition of many possible classical results, then this can be calculated from a prior quantum state using just the standard Schroedinger equation.

Well, yes, of course. The MWI is defined as QM with no collapse, and the SWE is deterministic, therefore we have realism....don't we?

Careful: in this context realism often means "collapse" or "unicity of outcome", like in Bell's paper. or even in EPR, where realism is thought only with the implicit assumption of unique universe.

In other context, physical realism means that physics is independent of us, like in "arithmetic realism" (arithmetic is independent of us).

Bruno

OK, I may have used the wrong terminology here. Maybe "hidden variables" means something different from what I thought. I assumed the MWI, being completely deterministic (a "block multiverse") had a definite state at all times, and that therefore there is stuff that we can't measure but is there, even so - which I thought meant hidden variables. But I may have messed up.

(That said, time symmetry could also be termed hidden variables, I think?)

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[Edgar L. Owen]

Jesse,

I agree that the evidence is that Einstein very probably believed in a non personal God of the universe. But there are those who try to prove he believed in a personal Biblical God and they do come up with some quotes they claim support their belief.

The quote you provide re an objective now are simply referencing the non-simultaneity cases of clock time which are well known but as I've pointed out ad nauseum do NOT falsify an actual present moment. That is clearly shown by the twins having NON-simultaneous clock times in the exact SAME present moment.

And as this quote points out "the concepts of happening and becoming are indeed NOT completely suspended, just more complicated". And he goes on to note that there is an "EVOLUTION of a three dimensional existence in time" which clearly indicates what he really believed in was a 4-dimensional universe in which things EVOLVE, happen and change. 

That is NOT block time. It's a 4-dimensional universe in which things change and happen and become, though in a more complicated way than the old Newtonian way.

So I would argue against your interpretation based on this quote...

And of course using the present "in the ordinary everyday way" of direct observation is itself strong evidence that a present moment does actually exist and block time doesn't, and that everybody that uses it that way implicitly and most explicitly believe that....

Edgar

[Edgar L. Owen]

Liz,

This is NOT an argument for block time. Not in the least. It implies just the opposite that events are actually happening...

Edgar

[Edgar L. Owen]

Ghibbsa,

The "implications of block time for individual lives" are very clear. It means you are a zombie with no free will in a mindless dead universe in which nothing actually happens and your miserable life and death are already written.

Of course it's not true, but that's what it means.

Edgar

[Edgar L. Owen]

LIz,

No, no, no! Treating time as a dimension is NOT (by definition) block time. That's a complete misrepresentation of block time because it is quite possible, and also correct, to treat time as a dimension IN WHICH a present moment moves along that time dimension. In the actual real world both clock time and p-time flow. There is NO FLOW of time in block time.

Block time has absolutely no concept of a present moment, and absolutely NO way to explain why everyone experiences a present moment, why they are in one and only one point of their timeline in those 4 dimensions.

As Stephen says "block time is a BS theory".

Edgar

[Jesse Mazer]

On Tue, Feb 4, 2014 at 8:19 AM, Edgar L. Owen <edga...@att.net> wrote:

Jesse,

I agree that the evidence is that Einstein very probably believed in a non personal God of the universe. But there are those who try to prove he believed in a personal Biblical God and they do come up with some quotes they claim support their belief.

But you said *you* thought his quotes on God were inconsistent, not just that some other people might incorrectly infer belief in a Biblical God from his quotes. Can you think of any comments of his that *you* think are inconsistent with a Spinoza-esque pantheist God?

 

The quote you provide re an objective now are simply referencing the non-simultaneity cases of clock time which are well known but as I've pointed out ad nauseum do NOT falsify an actual present moment. That is clearly shown by the twins having NON-simultaneous clock times in the exact SAME present moment.

He referred to "sections" of the four-dimensional structure and the idea that none of these "sections" can "represent 'now' objectively", so clearly he wasn't just talking about individual readings on local clocks, but rather the spacelike simultaneity surfaces (surfaces of constant coordinate time) used by inertial frames. Though as I've mentioned before, inertial frames can be defined in terms of a hypothetical *network* of clocks filling all of space, which have been "synchronized" in their rest frame, so in this sense simultaneity surfaces are based on clock readings. 

 

And as this quote points out "the concepts of happening and becoming are indeed NOT completely suspended, just more complicated".

Yes, just like plenty of eternalists would say.

 

And he goes on to note that there is an "EVOLUTION of a three dimensional existence in time" which clearly indicates what he really believed in was a 4-dimensional universe in which things EVOLVE, happen and change. 

No, he said that we "should think of physical reality as a four-dimensional existence, INSTEAD OF, AS HITHERTO, the evolution of a three dimensional existence." In other words, he was contrasting the older view of physical reality as "the evolution of a three dimensional existence" with the newer view of "a four-dimensional existence", and saying the latter is how we "should" think of things.

Jesse

[Edgar L. Owen]

Hi Jesse,

Well, we disagree here but thinking we know for sure the details of what Einstein believed is probably a lost cause - for me at least, but you of course can always call him up and ask him, since in your view he still actually exists as a block time time line!

Let me know when you get an answer and I'll be a believer in block time too!

:-)

Best,

Edgar

[David Nyman]

On 4 February 2014 10:14, Bruno Marchal <mar...@ulb.ac.be> wrote:

But perhaps we should rather think of the frog focus as continuing to be fundamentally panoptic (i.e. encompassing all the frog perspectives) except that "down there" the extrinsic simultaneity is intrinsically broken by the discrete perspective of each momentary frog. If so, one could then see Hoyle's heuristic as a frog's eye view of the experiential consequences of this broken simultaneity.

I think that is is what happen when we apply the theaeteus definition on provability, except that provability is already a symmetry broker, then the Theaetetus makes it even more assymetrical (irreflexive, even), and the miracle is more in the fact that, defining the physical reality from that move, we get the core symmetry back.

Yes, the idea I'm trying to convey is that the symmetry of the frog's panoptic view is broken, or breaks itself, as a consequence of its intrinsic non-simultaneity, and this, at least for me, is the intuition that Hoyle's heuristic fundamentally conveys. This internal asymmetry of simultaneity obviates any requirement to appeal to any further extrinsic principle of symmetry breaking, so Hoyle's selective principle becomes merely a conceptual ladder to be cast aside once we have used it to imaginatively descend "down here". In a different but related sense, the "physical symmetry" re-emerges from any one of the frog's discrete perspectives. I guess this is what you mean by the miracle, and yes, I do regard this as a major prize if indeed the comp assumption is correct.

 

I hope I will be able to clarify this for you with the self-reference (modal) logics.

I hope so too!

David

[Jesse Mazer]

On Tue, Feb 4, 2014 at 10:56 AM, Edgar L. Owen <edga...@att.net> wrote:

Hi Jesse,

Well, we disagree here

What part of what I said do you disagree with? Do you disagree that in the context of relativity, "sections" of the four-dimensional structure should be taken to refer to simultaneity surfaces? And do you not think that if someone says a sentence of the form "we should think of physical reality as A instead of, as hitherto, as B", this indicates that they are setting up a contrast between A and B, and endorsing A and suggesting that B is outdated? This is really quite a straightforward sentence structure! If you take this sentence as endorsing B than you either have terrible reading comprehension, or your desire to believe Einstein agreed with you is overriding your ability to read normally (confirmation bias).

 

but thinking we know for sure the details of what Einstein believed is probably a lost cause

Why should it be? He said plenty on the subject, we can look at his quotes, just as we would do if we wanted to know his opinion on any subject. (do you think it's a "lost cause" to determine whether he believed the Sun's gravity could deflect light rays, for example?) Aside from quotes already mentioned, if you want to educate yourself on the subject you might try reading the book Bruno mentioned, Pale Yourgrau's "Einstein and Gödel" which recounts the extensive discussions Einstein had with Gödel on the subject of block time.

Jesse

[meekerdb]

On 2/4/2014 2:25 AM, Bruno Marchal wrote:
>> The MWI is deterministic, however, and hence has hidden variables.
>
>
> But not "hidden variable" in the EPR sense. In the MWI, there are hidden universes, they
> are not variable, but terms in the universal wave, and we just don't know which terms
> apply to us. If it was hidden variable in the EPR sense, then by Bell, they would be
> non-local, and you would conclude falsely (like Clark) that the MWI has to be non local
> (which I doubt very much)

But is it non-local? The FPI is based on find yourself in a particular universe (where
the measurement was "up" say) so that's an indicial variable labeling that universe. Now
you may say that indicial label really only applies to the forward lightcone relative to
the measurement. But if is one of an EPR pair, it must also carry a variable value that
tells it it is correlated with the the other particle of the EPR pair, so that in the
overlap of their forward lightcones the statistis will violate Bell's inequality.
Otherwise you could get the same statistics using non-entangled pairs at the two measuring
devices.

Brent

[Jesse Mazer]

On Tue, Feb 4, 2014 at 12:17 PM, Jesse Mazer <laser...@gmail.com> wrote:

 

 Aside from quotes already mentioned, if you want to educate yourself on the subject you might try reading the book Bruno mentioned, Pale Yourgrau's "Einstein and Gödel" which recounts the extensive discussions Einstein had with Gödel on the subject of block time.

Minor correction: I just looked it up, the book is actually "Gödel Meets Einstein", it can be found here (used copies are available cheap): http://www.amazon.com/Godel-Meets-Einstein-Travel-Universe/dp/0812694082

Yourgrau also wrote another book on the same subject, "A World Without Time: The Forgotten Legacy of Gödel and Einstein": http://www.amazon.com/World-Without-Time-Forgotten-Einstein/dp/0465092942/

Incidentally, here's another quote by Einstein where he clearly rejects the idea of any objective global "present moment", from p. 45 of the book at http://books.google.com/books?id=0mc4BKpAyr0C&lpg=PP1&pg=PA45 --

"We shall now inquire into the definitive insights that physics owes to the special theory of relativity.

(1) There is no such thing as simultaneity of distant events"

Jesse

[Edgar L. Owen]

Jesse,

Come on now. The well established fact that it is impossible to always establish CLOCKTIME simultaneity of distant events does NOT require or even imply block time. 

What it actually implies is that everything is MOVING in clock time and if things actually move in clock time that is the opposite of block time. Nothing moves in a block universe.

I'm surprised you don't see this...

Edgar

[Jesse Mazer]

On Tue, Feb 4, 2014 at 2:00 PM, Edgar L. Owen <edga...@att.net> wrote:

Jesse,

Come on now. The well established fact that it is impossible to always establish CLOCKTIME simultaneity of distant events does NOT require or even imply block time. 

Einstein just says there is no "simultaneity of distant events", he doesn't suggest that there's some alternative to "clocktime simultaneity" which he believes in. As I understand it you definitely believe that there is such a thing as simultaneity of distant events, since you think there's a definite yes-or-no answer to whether they happen at the same p-time.

And I guess you're going to just ignore my point about the obvious meaning of a sentence of the form "we should think of physical reality as A instead of, as hitherto, as B", that such a sentence is endorsing A and rejecting B as outdated? No surprise there, you always seem to just drop the discussion once it goes down a line you'd have trouble answering without damaging your position (as with the issues I asked you to address at https://groups.google.com/forum/#!msg/everything-list/jFX-wTm_E_Q/BaKE8Sq-fN8J -- another post you simply ignored).

 

What it actually implies is that everything is MOVING in clock time and if things actually move in clock time that is the opposite of block time. Nothing moves in a block universe.

I have no idea what "moving in clock time" could mean (wouldn't "moving" in a time dimension require a second "meta-time" dimension to keep track of "changes" in an entity's position in the first time dimension?), or why you think a lack of absolute "clocktime simultaneity" should "imply" this. But if you'd care to explain in detail I would be happy to address the argument.

Jesse

[LizR]

On 4 February 2014 23:25, Bruno Marchal <mar...@ulb.ac.be> wrote:

On 04 Feb 2014, at 00:29, LizR wrote:

On 4 February 2014 12:23, Jesse Mazer <laser...@gmail.com> wrote:

On Mon, Feb 3, 2014 at 5:48 PM, <ghi...@gmail.com> wrote:

 

But more generically speaking, would this inference for blocktime sit at the edge of relativity or at its core. What I mean is, beyond that it is an implication of relativity, have there been or are there any prospects for developing blocktime as it arises from relativity to such point, predictions get made? Or any other kind of reinforcement? Or does blocktime go on to imply something beyond blocktime?

If "block time" is taken as a definite ontological statement about all times "existing" in exactly the same sense, rather than just referring to the idea of treating time as a dimension conceptually or in our mathematical models, then I think it's a metaphysical postulate that goes beyond anything directly implied by relativity. Relativity says that all frames, with their different definitions of simultaneity, are on equal footing as far as the laws of physics are concerned, but it doesn't deal with ontology. If someone proposes that one frame's definition of simultaneity is "metaphysically preferred" in the sense it defines the "true present", but adds the caveat that this frame is not in any way physically preferred so that no conceivable experiment could determine which frame it is, this wouldn't contradict the physics. It would be an "interpretation" of SR, similar to the different "interpretations" of QM which postulate different things about ontology (the real existence of other worlds in the MWI, or a single world with hidden variables in Bohmian mechanics, for example) but are indistinguishable experimentally. 

SR directly demonstrates block time via the relativity of simultaneity. This can be tested experimentally.

That said, if you subscribe to any form of Occam's razor or even a criteria of "elegance" when it comes to choosing between different metaphysical hypotheses, it seems a lot simpler to assume that there is no metaphysically preferred definition of simultaneity, just as I think many would agree the MWI is the simplest way of interpreting the physical theory of QM. Adding extra "purely metaphysical" entities to a theory, which don't correspond to anything that appears in the mathematical formalism of the theory itself (which would apply to things like a "true present" or to hidden variables in QM), seems a bit like postulating that there are invisible intangible elves sitting on each person's head which have no causal effects on anything we can measure; sure it's logically possible, but it seems like a very inelegant and arbitrary way for reality to work.

The MWI is deterministic, however, and hence has hidden variables.

But not "hidden variable" in the EPR sense. In the MWI, there are hidden universes, they are not variable, but terms in the universal wave, and we just don't know which terms apply to us. If it was hidden variable in the EPR sense, then by Bell, they would be non-local, and you would conclude falsely (like Clark) that the MWI has to be non local (which I doubt very much).

No, as I explained elsewhere, Bell's inequality rests on 4 assumptions, and the easiest assumption to remove is that time is asmmetric at the fundamental level (which in any case physics indicates it isn't, except for neutral kaon decay - which I dount has ever been used in an EPR experiment).

Locality and realism are almost certainly preserved, as Einstein suspected, even though Bell's inequality is violated.

[LizR]

On 4 February 2014 23:45, Bruno Marchal <mar...@ulb.ac.be> wrote:

On 04 Feb 2014, at 01:19, LizR wrote:

On 4 February 2014 12:44, Edgar L. Owen <edga...@att.net> wrote:

Liz,

You keep repeating your UNSUBSTANTIATED claim that both Newton and Einstein believed in block time.

It isn't a question of belief. Newtonian and Einsteinian machanics both imply the existence of a block universe.

I've repeatedly asked you to substantiate this claim with some actual quotes from them but you have been unable to do so.

Please provide quotes substantiating this or withdraw the claim. That's only fair...

Obviously Newton didn't use that phrase. Equally obviously it's implied by his equations, as Laplace realised.

Yes, I was thinking of Laplace. Why did I wrote Pascal?

Well, they were both famous scientists / mathematicians / philosophers (and I think both French!)

[LizR]

On 4 February 2014 23:58, Bruno Marchal <mar...@ulb.ac.be> wrote:

On 04 Feb 2014, at 01:55, LizR wrote:

On 4 February 2014 13:32, Jesse Mazer <laser...@gmail.com> wrote:

On Mon, Feb 3, 2014 at 6:29 PM, LizR <liz...@gmail.com> wrote:

SR directly demonstrates block time via the relativity of simultaneity. This can be tested experimentally.

The relativity of simultaneity is a claim about physics, not metaphysics. Specifically, it's a claim that the laws of physics work exactly the same in all inertial frames, which have different definitions of simultaneity. If someone agrees that no frame's definition of simultaneity is "preferred" in any physical sense, but that one is "metaphysically preferred" in a way that is wholly invisible to all possible experiments, this would not contradict SR or the relativity of simultaneity as a physical principle.

OK, maybe what I should have said is that no one has come up with an explanation for the ROS that doesn't include the concept of space-time being a 4D manifold.
I'm not sure if that leaves us with a physical or metaphysical problem (or maybe no problem at all!)

That said, if you subscribe to any form of Occam's razor or even a criteria of "elegance" when it comes to choosing between different metaphysical hypotheses, it seems a lot simpler to assume that there is no metaphysically preferred definition of simultaneity, just as I think many would agree the MWI is the simplest way of interpreting the physical theory of QM. Adding extra "purely metaphysical" entities to a theory, which don't correspond to anything that appears in the mathematical formalism of the theory itself (which would apply to things like a "true present" or to hidden variables in QM), seems a bit like postulating that there are invisible intangible elves sitting on each person's head which have no causal effects on anything we can measure; sure it's logically possible, but it seems like a very inelegant and arbitrary way for reality to work.

The MWI is deterministic, however, and hence has hidden variables.

No. The Schroedinger equation which calculates wavefunction evolution in QM is already fully deterministic, the MWI just dispenses with the extra postulate of "wavefunction collapse" on measurement, which is the only random element in QM. Determinism only implies hidden variables if you assume each experiment has a *unique* outcome, and that this outcome is generated in a deterministic way by the initial conditions. If you assume that the physical state at the end of an experiment is a quantum state that's a superposition of many possible classical results, then this can be calculated from a prior quantum state using just the standard Schroedinger equation.

Well, yes, of course. The MWI is defined as QM with no collapse, and the SWE is deterministic, therefore we have realism....don't we?

Careful: in this context realism often means "collapse" or "unicity of outcome", like in Bell's paper. or even in EPR, where realism is thought only with the implicit assumption of unique universe.

In other context, physical realism means that physics is independent of us, like in "arithmetic realism" (arithmetic is independent of us).

Ah, I thought it meant there was no point (in say an EPR experiment) when the values of variables - the polarisation of a photon, say - was genuinely undefined, as opposed to merely unmeasurable.

In that sense, time symmetry and the MWI both preserve what I called realism - all variables are defined at all times - and locality - no FTL.

[Jesse Mazer]

As I've said to you in the post at http://www.mail-archive.com/everyth...@googlegroups.com/msg46130.html , the type of time-symmetry seen in modern physics--which just says that the same laws can be used to retrodict past states as are used to predict future states, but doesn't say you *need* information about the future as well as the past to predict the state in a given region of spacetime--is not enough to evade the conclusions of Bell's theorem. In order to do that you'd need either a theory where determining the state of a region does require knowing both its past and its future, or you'd need some strong restrictions on the possible boundary conditions, both of which would be pretty exotic assumptions, not ones I'd consider to be the "easiest" modification of Bell's assumptions. In the case of the type of dynamical time-symmetric (or CPT-symmetric) theories that physicists have found useful in describing nature, where you can use a set of initial conditions to predict a later state, the argument about conditioning on a slice of the past light cone I mentioned at http://www.mail-archive.com/everyth...@googlegroups.com/msg45832.html (and which matches Bell's discussion of conditioning on slices of past light cones in his "La nouvelle cuisine" paper) still works fine to show that if the theory is local realistic (and doesn't include parallel universes), Bell inequalities should not be possible to violate.

Jesse

[LizR]

There is nothing exotic about the state of a photon being determined by future boundary conditions. A photon has a very limited memory and doesn't partake in thermodynamics on its own. The onus is to show why it wouldn't be influenced equally by past and future boundary conditions if time is fundamentally symmetric, or to show how time isn't fundamentally symmetric, from a photon's point of view (which means doing so without reference to thermodynamics, which is an emergent macroscopic phenomenon).

Feynmann's absorober theory attempted to do this, but I don't think it deals with a case where a photon is emitted and absorbed within an EPR experiment.

--

[meekerdb]

On 1/31/2014 11:05 PM, LizR wrote:

There seems to be a bit of confusion about this idea. Some people on the list seem to abhor the idea of a block universe, but when they attack the concept, they invariably go for straw men, making statements like "change can't happen in a block universe" (which are obviously nonsense, or Einstein et al would hardly have entertained the idea in the first place).

So, I'd like to maybe clarify what the idea means, and give them a proper target if they still want to demolish it.

A block universe is simply one in which time is treated as a dimension. So Newtonian physics, for example, specified a block universe, in which it was believed (e.g. by Laplace) that in principle the past and future could be computed from the state of the present. The Victorians made much of time being the fourth dimension, probably most famously in Wells' "The Time Machine". This was the Newtonian concept of a block universe, and was generally treated quite fatalistically (Wells didn't indicate that history could be changed, for example).

Then special relativity came along and unified space and time into space-time. The reason SR gives rise to a block universe is the relativity of simultaneity. You can slice up space-time in various ways which allow two observers to see the same events occurring in a different order. Hence there is no way to define a "hyperplane of simultaneity" that can be agreed upon by all observers as being a present moment. This indicates that space-time is a four-dimensional arena in which events are embedded. Indeed, I have never heard of an alternative explanation of the relativity of simultaneity that gets around this result - if it's correct, space-time is a block universe, that is to say, time is "just" another dimension.

I think you are reading too much into special relativity.  What makes SR different is that only spacetime interval is meaningful, whereas for Newton both duration and distance were separately invariant.  Sometimes you can work problems just in terms of the 4-intervals and 4-momenta and not introduce any coordinate system.  The coordinates (t,x,y,z) that give a block-time picture are in principle dispensable (and they can even be misleading when t is identified as "the real time").  It's like giving locations on Earth latitude and longitude coordinates instead of citing a string of transit measurements and triangulations to give the relative location of two things.  The latter is too messy to calculate with.  But notice, that is exactly what GPS does.  It locates every GPS receiver in spacetime in terms of 4-space triangulation relative to known orbital events.  Then the receiver converts that to lat and long for our convenience.

So I would say that treating time as a dimension is a good way of looking at things, but it's not *forced* on us by SR.

Brent

[Jesse Mazer]

On Tue, Feb 4, 2014 at 3:59 PM, LizR <liz...@gmail.com> wrote:

There is nothing exotic about the state of a photon being determined by future boundary conditions.

You *could* determine the state of any system in quantum theory by future boundary conditions, but what would be exotic is the assumption that neither past nor future boundary conditions are sufficient on their own, that you need a combination of both. That just isn't how it works in quantum theory, so you'd need some fundamentally different theory, unlike the ones physicists know, for that to be true. Such a thing is certainly logically possible, but you can't really point to the time symmetry of existing theories as evidence that it's the "easiest" of ways to explain away Bell's results.

 

A photon has a very limited memory and doesn't partake in thermodynamics on its own.

I don't know what you mean by "memory", or how thermodynamics is relevant. Technically you should be able to apply thermodynamics to any system which can have multiple states, including a single particle in a box, just by making some choice about how to coarse-grain all the "microstates" into a set of "macrostates".

 

The onus is to show why it wouldn't be influenced equally by past and future boundary conditions if time is fundamentally symmetric

You can say it's influenced equally, in the sense that complete knowledge of either one can be used to determine the quantum state of a system. But again, that's fundamentally different from saying neither set of boundary conditions alone is sufficient, that you need to take into account both at once.

Jesse

[meekerdb]

On 2/4/2014 1:11 PM, Jesse Mazer wrote:

On Tue, Feb 4, 2014 at 3:59 PM, LizR <liz...@gmail.com> wrote:

There is nothing exotic about the state of a photon being determined by future boundary conditions.

You *could* determine the state of any system in quantum theory by future boundary conditions, but what would be exotic is the assumption that neither past nor future boundary conditions are sufficient on their own, that you need a combination of both. That just isn't how it works in quantum theory,

Some people think it is.  When the past boundary condition doesn't predict a definite future condition, then adding a future boundary condition can resolve it.  That's how Stenger effectively gets a non-local effect in an EPR experiment.

Brent

[Jesse Mazer]

On Tue, Feb 4, 2014 at 4:39 PM, meekerdb <meek...@verizon.net> wrote:

On 2/4/2014 1:11 PM, Jesse Mazer wrote:

On Tue, Feb 4, 2014 at 3:59 PM, LizR <liz...@gmail.com> wrote:

There is nothing exotic about the state of a photon being determined by future boundary conditions.

You *could* determine the state of any system in quantum theory by future boundary conditions, but what would be exotic is the assumption that neither past nor future boundary conditions are sufficient on their own, that you need a combination of both. That just isn't how it works in quantum theory,

Some people think it is.  When the past boundary condition doesn't predict a definite future condition, then adding a future boundary condition can resolve it.  That's how Stenger effectively gets a non-local effect in an EPR experiment.

If we ignore the idea of a "collapse" of the quantum state on measurement, isn't the evolution of the wave function deterministic, so that knowing the complete past quantum state of an isolated system is always enough to calculate the later quantum state? Is Stenger basically arguing that the "collapse" on measurement is not really random but is determined by a combination of past and future boundary conditions?

Jesse

[meekerdb]

It's still really random (or really FPI) but information as to which way the polarizer is oriented is communicated from one detector to the other via the zig-zag back to the emitter and forward to the other dectector.  So yes, the polarizer orientations are future boundary conditions. At least that's the way I think it's supposed to work.

Brent

[LizR]

Well obviously nothing's *forced* on us by SR - apparently it can even be made compatible with absolute time, at least for some people!

So ..... you're saying that looking at space-time as dimensional isn't forced on us by SR, correct? (I assume, given that SR unifies space and time, you aren't just separating out time, but saying this is true of space-time, yes?)

Well, of course this is suggested by some TOEs (like comp). But that would be an unnecessary complication in this discussion, imho.

Still, from a "Machean" viewpoint this may be true, and Einstein was keen on Mach's ideas. Or at least Mach would say you don't need any particular coordinate system to do calculations in SR - the coordinate system you use for a given calculation is relative to the system you're using, making it arbitrary in terms of the rest of the universe. But you are apparently making a stronger claim.

You said we don't need a coordinate system at all, we can just use 4-momenta and 4-intervals - so using those doesn't imply or define a 4D coordinate system? So what do they imply? Do they (hehe) just operate in a vacuum? Is this some sort of (I think it was Julian Barbour) -ish vision of geometry swimming around unsupported by any external framework? Maybe you could be more precise, I'm afraid my knowledge of SR is limited to things like the website I linked to, which tend to use space-time, light cones, worldlines etc as part of the furniture.

But anyway, I don't see the connection with block universes. The argument from SR to a block universe involves the relativity of simultaneity, so unless you are saying that isn't a consequence of SR, I'm not sure what the relevance of all this is.

(Well, unless it's just to give fuel to people who will twist what you're saying around to say there's no implication of a 4D manifold in SR, of course. Are you just troll-baiting?)

[LizR]

On 5 February 2014 10:39, meekerdb <meek...@verizon.net> wrote:

On 2/4/2014 1:11 PM, Jesse Mazer wrote:

On Tue, Feb 4, 2014 at 3:59 PM, LizR <liz...@gmail.com> wrote:

There is nothing exotic about the state of a photon being determined by future boundary conditions.

You *could* determine the state of any system in quantum theory by future boundary conditions, but what would be exotic is the assumption that neither past nor future boundary conditions are sufficient on their own, that you need a combination of both. That just isn't how it works in quantum theory,

Some people think it is.  When the past boundary condition doesn't predict a definite future condition, then adding a future boundary condition can resolve it.  That's how Stenger effectively gets a non-local effect in an EPR experiment.

The point is that if there are both past AND future boundary conditions on a quantum entity like a photon, its state in between has to reflect them both. One isn't favoured over the other (assuming time symmetric physics, of course).

This explains delayed-choice experiments, by the way, as well as EPR correlations.

[LizR]

I imagine he's saying the measurement constitutes a boundary condition.

We assume no collapse, I think. Collapse IS time asymmetric, so the time symmetry argument goes out the window if wavefunctions can be shown to collapse. The MWI, however, should be time symmetric at the same level that physics is (recombining universes as often as they split). But there is a huge entropy gradient at the coarse grained level so a huge asymmetry of split-vs-merge at that level.

[meekerdb]

On 2/4/2014 2:35 PM, LizR wrote:

You said we don't need a coordinate system at all, we can just use 4-momenta and 4-intervals - so using those doesn't imply or define a 4D coordinate system?

Sure they imply that a 4D coordinate system is possible, in fact many different ones.  This is just like map surveyors who measure a lot of distance and angles between points can infer that they're on a spheroid and hence can introduce a consistent coordinate system.  But the distances and angles are more fundamental, i.e. operational, than the coordinate system which has a lot of arbitrariness in it. But we don't say we know we live on a spheroid because of the relativity of latitude.

The point only makes a difference when people are asking things like does SR mean that the block universe is really real.  I think even the phrase "relativity of simultaneity" is kind of misleading.  It seems to imply that distant events are simultaneous with local ones relative to some frame.  But in general it's only that given two spacelike events there exists a frame in which they are simultaneous.  If you add a third event then there may not be any frame that will make the three simultaneous.  So I'd rather say there is no such thing as simultaneity for distant events. 

Brent

[LizR]

On 5 February 2014 12:07, meekerdb <meek...@verizon.net> wrote:

On 2/4/2014 2:35 PM, LizR wrote:

You said we don't need a coordinate system at all, we can just use 4-momenta and 4-intervals - so using those doesn't imply or define a 4D coordinate system?

Sure they imply that a 4D coordinate system is possible, in fact many different ones.  This is just like map surveyors who measure a lot of distance and angles between points can infer that they're on a spheroid and hence can introduce a consistent coordinate system.  But the distances and angles are more fundamental, i.e. operational, than the coordinate system which has a lot of arbitrariness in it. But we don't say we know we live on a spheroid because of the relativity of latitude.

Well if you want to be picky we don't know that either, we only have those blooming buzzing sense impressions from which we assume the assume surveyors extracted their assumed conclusions. I was just operating at a particular level of description, which let's face it is fairly common when trying to explain something. ("Today we will be discussing philosophy, but first we need to discuss what we mean be "we", "discuss", "philosophy" and "today"...amongst other things.")

The point only makes a difference when people are asking things like does SR mean that the block universe is really real.  I think even the phrase "relativity of simultaneity" is kind of misleading.  It seems to imply that distant events are simultaneous with local ones relative to some frame.  But in general it's only that given two spacelike events there exists a frame in which they are simultaneous.  If you add a third event then there may not be any frame that will make the three simultaneous.  So I'd rather say there is no such thing as simultaneity for distant events. 

Well, we don't know if anything is really real. I wasn't intending to discuss metaphysics on this thread; if you want to do that, maybe you could start another one. All I'm arguing is that SR (and to some extent NM) imply a block universe as the simplest explanatory framework (via the usual application of Occam), plus throw in a few points about the circularity of competing explanations. If that's wrong then I will go out into the garden and eat worms, but I don't think that anything you're saying actual conflicts with that.... as far as I can tell. But then I'm not sure what point you're trying to make, unless you're just to take apart everything I say in order to make me look and feel stupid (which, you know, I can do quite well myself).

[meekerdb]

On 2/4/2014 3:25 PM, LizR wrote:
..

Well, we don't know if anything is really real. I wasn't intending to discuss metaphysics on this thread; if you want to do that, maybe you could start another one. All I'm arguing is that SR (and to some extent NM) imply a block universe as the simplest explanatory framework (via the usual application of Occam), plus throw in a few points about the circularity of competing explanations. If that's wrong then I will go out into the garden and eat worms, but I don't think that anything you're saying actual conflicts with that.... as far as I can tell. But then I'm not sure what point you're trying to make, unless you're just to take apart everything I say in order to make me look and feel stupid (which, you know, I can do quite well myself).

My apologies.  That was not my intent at all and you are obviously a very smart person.  But I think we are talking metaphysics - at least Bruno is.  His theory is pretty 'meta' relative to physics.

Brent

[LizR]

Thank you, I do sometimes over-react.... sorry.

I was trying to not get into comp, because it entails a block universe (or an "atemporal realm") so there's no point in attempting to use it as part of an explanation of how BUs arise in SR, that would (presumably) be circular. I just wanted to explain how SR (as commonly envisaged, at least, by people explaining it "for dummies") gives rise to a block universe - modulo the usual caveats about theories vs interpretations, etc.

Given that Edgar engaged the caps lock and started on some nonsense - looking for quotes in which Newton claimed his undying belief in block time, or whatever - I wanted to keep things as simple as possible, so even he would have no (genuine) excuses to misunderstand the argument. I felt that saying "you don't have to use a coordinate system..." was just giving him more opportunities to get the wrong end of the stick and start beating about the bush with it.

[ghi...@gmail.com]

On Tuesday, February 4, 2014 6:31:06 AM UTC, Brent wrote:

On 2/3/2014 9:41 PM, ghi...@gmail.com wrote:

So do you think block time is what is inferred as a reality by each of these  space and time variants?

You mean "implied by"?  It doesn't imply anything about which is right, because it applies equally to all of them, just like we could label every point with a latitude and longitude on a torodial Earth. 

Brent

 

Yeah implied, sorry about that. I was really just interested in your personal view as to whether blocktime is the best candidate for what's real. In the sense Liz and come out for blocktime pretty unambiguously.  

[meekerdb]

It's the easiest way to think about SR.  And it works for GR too so long as you avoid closed time-like loops.  But GR and QM seem to be inconsistent, so it's hard to say either one is a good candidate for what's real.  I just think they're very good approximations over some domains.

Brent

[LizR]

On 5 February 2014 13:18, meekerdb <meek...@verizon.net> wrote:

It's the easiest way to think about SR.  And it works for GR too so long as you avoid closed time-like loops.  But GR and QM seem to be inconsistent, so it's hard to say either one is a good candidate for what's real.  I just think they're very good approximations over some domains.

Fair enough. Although QM also uses a form of block time (in fact Newtonian, if anything).

(That plus I have a hard time imagining what else time could possibly be like - even presentism is only block time in more dimensions ... although that short story "Flux" gives an idea)

[ghi...@gmail.com]

On Tuesday, February 4, 2014 7:04:49 AM UTC, Liz R wrote:

On 4 February 2014 16:56, <ghi...@gmail.com> wrote:

Thanks for all that. Very interesting. So what sort of implications would block time have for individual lives. Do they happen only onetime while their time is being actively blocked in? Or does blocktime exist statically as the end-to-end story of the universe? 

Block time doesn't have any implications for individual lives. It can't make a difference to everyday life, because obviously it predicts that everyday life will be exactly what we observe it to be (otherwise it could be shown to be false). It would seem that the 4D space-time manifold "exists as the story of the universe".

 

 

I appreciate the construction is the chain of relations, but does anyone say whether the relations necessarily happen like a domino effect from the big bang through, just the one time? Or can they get washed through like waves of an incoming tide? is another version of me happening on the wave just behind the one I'm on?

This interesting possibility is explored in Barrington Bayley's novel "Collision with Chronos" which I heartily recommend even though as far as we know it doesn't have anything to do with real physics!

 

I'm going to have fire up a spreadsheet to keep some record of these book references.  

For things to wash through block time you need an extra time stream. So you move your block universe out to 5D - 3 space and 2 time dimensions. There's no reason to posit this to explain any observed phenomenon. A 4D space-time manifold appears to be sufficient.

 

I didn't mean it that way. I was using the wave just as a way to illustrate what I meant. I didn't say so of course. But that's totally your fault.  

 

I think what I'm realty asking is what is blocktime giving the world? It's giving us a deeper vision of reality (if true). But if it is objectively true, what purpose or utility does it serve, if any?

My experience when I ask something like that is normally puzzlement..."what do you mean what purpose/utility?' It's an implication of relativity! :o)

Well, it's more an ontological underpinning of relativity, since the whole thing is based around the concept that the universe is a 4D manifold (a warped one in GR). So I guess the puzzlement is similar to if you'd asked "what is the purpose/utility of the big bang, or of evolution?" It sounds like a theological / teleological question.

 

yeah I see what you mean. 

 

But it's strange really. Where are knowledge is strongest, at the core of our own universe, there is no part of it that does not serve a fundamental purpose in the workings of physical law. If someone asked what purpose were served by neutrinos, or dark matter, or gamma rays, gravity....there would be several interpretations involving some utility in the scheme of things.

 

But what happens at the edges..of our theories, of our knowledge, is completely different. And tightly linked to what action we take. This one here is in the same class as what takes place with QM. An interpretation. Both times then, MWI and this time, the result is an - albeit completely differently configured - sort of translation even from a set of relations in one universe, to the same relations distributed in a multiverse-like construction.

It isn't really an interpretation, except insofar as all physics could be called that (I think "model" would be a better term). It's one of the entities postulated by SR and GR, much as (say) mass is.  I suppose it has the benefit of being the only view of time that actually makes sense - at least, I've never seen a physical theory that explains time any other way, and it's hard to imagine any other way of explaining it - although presentism expands the scope of the block universe to extra time dimensions, but I don't consider that a good thing.

 

Well what I'd say is you've definitely given a very good showing for blocktime. I'm nowhere near equipped to put up a counter argument. It's an interesting idea...that I could accept....if there was a way to lose the infinity. Which I'll be thinking about. But that's just personal stuff. All in all, if I was a good popperian I'd definitely be accepting your explanation as literally true. But I'm not a good popperian :O) 

 

Obviously we don't see this as a multiverse in that blocktime happens along the passage of time we associate with this single universe. But relative to the old concept of a single version of objects moving through the passage of time, blocktime is a multiverse-like construction IMHO.

QM posits a block multiverse. 

 

Guess what we're getting could be objective , or it could be an artefact of doing something improper, brought about by circumstances involving invoking a process of interpretation of some sense of an exposed edge of a theory.

Any idea what? 

 

I actually do Liz, but I don't think it'd be fair to put you through it, as my standard of explanation needs to be higher. I probably shouldn't touch on the matter at all...but the process helps to progress me..and anyway I just can't help myself. I'm always speaking insights from my theory...that's why no on ever has a clue what I'm going on about  :O ()

 

Two possibilities

Only one of them has had amazing predictive success, however :-)

 

Don't be so hard on yourself Liz. Just kidding. 

 

I'm presuming you don't mean blocktime directly predicts...but relativity. If so, I take your point obviously.

 

If you meant blocktime directly, I'd love to hear the prediction.  

[LizR]

On 5 February 2014 13:31, <ghi...@gmail.com> wrote:

I'm presuming you don't mean blocktime directly predicts...but relativity. If so, I take your point obviously.

If you meant blocktime directly, I'd love to hear the prediction.  

I meant relativity, but that is based around the concept of space-time being a 4D manifold, although Brent has pointed out that we could dispense with that idea in a strictly operational definition - and I have pointed out that most TOEs dispense with it, since they want to start from something simpler than space-time. But in standard textbooks on relativity you will find Minkowski diagrams, light cones, world-lines and suchlike, as well as mentions of space-time being a 4-dimensional manifold.

I'm not sure what predictions could be made from the existence of block time apart from simultaneity being relative.

[Bruno Marchal]

On 04 Feb 2014, at 17:46, David Nyman wrote:

On 4 February 2014 10:14, Bruno Marchal <mar...@ulb.ac.be> wrote:

But perhaps we should rather think of the frog focus as continuing to be fundamentally panoptic (i.e. encompassing all the frog perspectives) except that "down there" the extrinsic simultaneity is intrinsically broken by the discrete perspective of each momentary frog. If so, one could then see Hoyle's heuristic as a frog's eye view of the experiential consequences of this broken simultaneity.

I think that is is what happen when we apply the theaeteus definition on provability, except that provability is already a symmetry broker, then the Theaetetus makes it even more assymetrical (irreflexive, even), and the miracle is more in the fact that, defining the physical reality from that move, we get the core symmetry back.

Yes, the idea I'm trying to convey is that the symmetry of the frog's panoptic view is broken, or breaks itself, as a consequence of its intrinsic non-simultaneity, and this, at least for me, is the intuition that Hoyle's heuristic fundamentally conveys. This internal asymmetry of simultaneity obviates any requirement to appeal to any further extrinsic principle of symmetry breaking, so Hoyle's selective principle becomes merely a conceptual ladder to be cast aside once we have used it to imaginatively descend "down here". In a different but related sense, the "physical symmetry" re-emerges from any one of the frog's discrete perspectives. I guess this is what you mean by the miracle, and yes, I do regard this as a major prize if indeed the comp assumption is correct.

OK.

Thanks for the nice summaries too, in some of your post.

 

I hope I will be able to clarify this for you with the self-reference (modal) logics.

I hope so too!

I think the people begin to be prepare for it. Now, there are many posts, and the things of life, ... ASAP.

Bruno

David

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[Bruno Marchal]

On 04 Feb 2014, at 18:19, meekerdb wrote:

> On 2/4/2014 2:25 AM, Bruno Marchal wrote:
>>> The MWI is deterministic, however, and hence has hidden variables.
>>
>>
>> But not "hidden variable" in the EPR sense. In the MWI, there are
>> hidden universes, they are not variable, but terms in the universal
>> wave, and we just don't know which terms apply to us. If it was
>> hidden variable in the EPR sense, then by Bell, they would be non-
>> local, and you would conclude falsely (like Clark) that the MWI has
>> to be non local (which I doubt very much)
>

> But is it non-local? The FPI is based on find yourself in a
> particular universe (where the measurement was "up" say) so that's
> an indicial variable labeling that universe.

Yes, but in EPR, the particles did interact, and their entanglement
means that in each partition of the multiverse they inherit of the
opposite spin. So when Alice makes a measurement, she only select the
relevant partition, without making any action at a distance.
When you do the math, you see that no non-locality appears in any term
of the wave.



> Now you may say that indicial label really only applies to the
> forward lightcone relative to the measurement. But if is one of an
> EPR pair, it must also carry a variable value that tells it it is
> correlated with the the other particle of the EPR pair, so that in
> the overlap of their forward lightcones the statistis will violate
> Bell's inequality.

Assuming some collapse, or unicity of outcome.



> Otherwise you could get the same statistics using non-entangled
> pairs at the two measuring devices.

I don't think so. The two particles did interact and then where
separated at light speed. Then the measurement, without collapse,
determine the common partitions shared by Alice and Bob.
That is why Alice can quantum-teleport a photon by doing a
measurement, and then sending by classical means the outcome to Bob,
which then know which corresponding measurement it has to do to
retrieve Alice's photon state.

I am rather confident that the MWI restores Einstein's locality, as
well as the physical 3p-determinacy.
(and this without using the symmetry of time and *special
conspiratorial boundaries conditions*).

Bruno



>
> Brent

[Bruno Marchal]

OK. But time symmetry still asks fro special boundary condition, and seems to me to still look like using ad hoc information to select one reality against others. I agree with Deutsch's idea that Cramer transactional theory is still a MWI, + initial conditions selecting a reality.

Bruno

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[David Nyman]

On 5 February 2014 09:33, Bruno Marchal <mar...@ulb.ac.be> wrote:

Thanks for the nice summaries too, in some of your post.

I hope I didn't garble them too badly :)

David 

[Bruno Marchal]

OK.

In monist theories, we have to handle the metalevel at the base level. Everett do meta-physics, by embedding the physicists in the physical domain: physicists are assumed to obey the quantum physical laws. I do this by embedding the mathematician in math, but of course that is what Gödel did, by the arithmetization of meta-arithmetic.

Zoologist can do that because it is general agreed that zoologist are animals. We can imagine a zoologist studying the rate or reproductivity of zoologists!

Botanist cannot do that, because it is generally agreed that botanists are not plants.

Bruno

http://iridia.ulb.ac.be/~marchal/

[Edgar L. Owen]

Jesse,

A couple of points in response:

1. Even WITHOUT my present moment, the well established fact of a 4-d universe does NOT imply block time nor require it. Clock time still flows just fine in SR and GR. No clock time simultaneity of distant (relativistic is a better descriptor) events does NOT imply time is not flowing at those events. This is quite clear. It's a fundamental assumption of relativity that time flows.

In fact relativity itself conclusively falsifies block time as it requires everything to be at one and only one point in clock time due to the fact that everything always travels at the speed of light through spacetime. I find it baffling that so many can't grasp this simple fact.

2. You complain about me not answering a few of your questions. As I've explained before I have limited time to post here because running my business keeps me very busy.

And please note that a lot of my posts have received NO answers at all either, e.g.

a. Several major posts, some as new topics, on my theory of how spacetime emerges from quantum events. Apparently this has just sailed over everyone's heads with not a single meaningful comment, not even any negative ones which is pretty surprising among this crowd! Apparently no one is interested in understanding the nature of time at the quantum level?

b. My post on a solution to Newton's Bucket. Also no relevant responses.

c. Several thought experiments lending very strong support to my present moment theory, posted just a couple days ago. Again zero response. And weren't those directed to YOU?

d. Several thought experiments designed to dig into the fine points of various aspects of time dilation. Again only a vague comment or two on 'asymmetry' but zero actual analysis of the points I raised.

e. Several other new topics on basic issues of science and epistemology. Again no relevant responses.

So don't be so quick to criticize me for not responding to every one of your questions. I received several hundred emails a day. I respond to most, delete some, but have a list of several dozen from this forum I hope to reply to given time. And when I do reply to posts with substantive topics, I always try to give the time to reply carefully and reply only when my responses have been well thought out...

So with limited posting time I have to be selective in my responses. Others here seem to have a lot more time available to post here and wish I did also...

As for your comment that "you have no idea what moving in clock time could mean" pull your head out of your physics books and watch your watch for a little while and see if the hands are moving. If not, you are in block time. If they are, you are in the normal reality that everyone else is. And actually yes, the fact that clock time does move perceptibly DOES imply a separate present moment in which clock time moves. You've hit on one of the major arguments FOR a present moment. 

But I know this direct observation that you can repeat over and over and over and confirm, (which has the same status of all scientific observations and measurements) doesn't carry any weight at all with you. However in denying it you are denying the most basic fact of your own existence.

Edgar

On Tuesday, February 4, 2014 2:41:56 PM UTC-5, jessem wrote:

On Tue, Feb 4, 2014 at 2:00 PM, Edgar L. Owen <edga...@att.net> wrote:

Jesse,

Come on now. The well established fact that it is impossible to always establish CLOCKTIME simultaneity of distant events does NOT require or even imply block time. 

Einstein just says there is no "simultaneity of distant events", he doesn't suggest that there's some alternative to "clocktime simultaneity" which he believes in. As I understand it you definitely believe that there is such a thing as simultaneity of distant events, since you think there's a definite yes-or-no answer to whether they happen at the same p-time.

And I guess you're going to just ignore my point about the obvious meaning of a sentence of the form "we should think of physical reality as A instead of, as hitherto, as B", that such a sentence is endorsing A and rejecting B as outdated? No surprise there, you always seem to just drop the discussion once it goes down a line you'd have trouble answering without damaging your position (as with the issues I asked you to address at https://groups.google.com/forum/#!msg/everything-list/jFX-wTm_E_Q/BaKE8Sq-fN8J -- another post you simply ignored).

 

What it actually implies is that everything is MOVING in clock time and if things actually move in clock time that is the opposite of block time. Nothing moves in a block universe.

I have no idea what "moving in clock time" could mean (wouldn't "moving" in a time dimension require a second "meta-time" dimension to keep track of "changes" in an entity's position in the first time dimension?), or why you think a lack of absolute "clocktime simultaneity" should "imply" this. But if you'd care to explain in detail I would be happy to address the argument.

Jesse

[Edgar L. Owen]

Jesse,

I didn't answer these 3 because you are once again describing well known aspect of CLOCK time simultaneity with which I probably agree. These have nothing to do with the concept of a present moment independent of clock time within which clock times run at different rates.

You need to understand the distinction.

Refer to my 2 thought experiments of a day ago. 1. The billion twins example. 2. The all observers in the universe example. 

However these won't do you any good until you understand and accept the basic well established FACT that the clock times of the twins differ in the exact same present moment they both share. Wiggle as you will that is a firmly established fundamental observable FACT which both observers agree upon.

Until you get that there is really no sense in discussing it further. Otherwise we are just spinning our wheels...

Edgar

On Monday, February 3, 2014 11:00:49 PM UTC-5, jessem wrote:

On Mon, Feb 3, 2014 at 8:40 PM, Edgar L. Owen <edga...@att.net> wrote:

Liz,

Talk about confirmation bias! It's SOP when a person can't come up with a real objective scientific rebuttal to an argument that they just flame and retreat. How awful it would be if facts and rational arguments changed their belief system! Goodness gracious, can't let that happen...

:-)

Speaking of simply retreating when one can't come up with a scientific rebuttal in order to avoid having one's beliefs challenged by rational argument, do you ever plan to respond to the following 3 posts of mine?

1. The one at https://groups.google.com/d/msg/everything-list/HeLo1QmdHFQ/4pDpJ6WXYgkJ where I pointed out that when the matter field is more irregular than the "perfect fluid" of the FLRW model, there is no obvious "natural" way to divide up 4D spacetime into a series of 3D slice, since there's no longer a unique choice of slicings that ensures the matter field on each slice is perfectly homogenous...so as I asked, what criteria would you propose to use to decide which of various possible slicings represents p-time? Or would you admit that you have no idea what physical criteria, if any, could choose between competing simultaneity conventions in a universe where matter isn't distributed in a perfectly homogenous way?

2. The one at https://groups.google.com/d/msg/everything-list/HeLo1QmdHFQ/Mw8jXkmytGoJ where I continued with the analogy to 2D geometry, and pointed out that the same logic you seem to be using to get the conclusion of a truth about which events happened at the "same point in time" independent of coordinate system could equally well be used to argue for a truth about which points on different roads were at the "same point in y" independent of a particular choice of x and y axes, which seems obviously silly...but as I said, "If you agree it's silly in the 2D case, then you still need to explain what the relevant difference is that does *not* lead you to conclude there must be such an objective truth about common y-values, even though every step of the argument up until then maps perfectly onto your own argument about time."

3. The one at https://groups.google.com/d/msg/everything-list/HeLo1QmdHFQ/eZSEOw-ilXUJ where I asked if you were asserting there's just one point on an observer's worldline that represents his "actual local time", or if you just meant that each point on an observer's worldline has its own definition of the "local time" without presupposing that only one of those points could be "correct". As I pointed out, if you are *assuming* the former at the start of your argument, then your entire argument is merely an exercise in circular reasoning, since idea of a privileged point on each object's worldline that is happening at the "present moment" is precisely what you were trying to demonstrate, so you can't just assume it from the start.

 

Jesse

[Jesse Mazer]

On Wed, Feb 5, 2014 at 11:22 AM, Edgar L. Owen <edga...@att.net> wrote:

Jesse,

I didn't answer these 3 because you are once again describing well known aspect of CLOCK time simultaneity with which I probably agree.

Uh, no they weren't, each of them concerned questions about YOUR definitions and arguments about simultaneity in p-time.

--question 1 dealt with the question of how YOU would define p-time simultaneity in a cosmological model where there's no way to slice the 4D spacetime into a series of 3D surfaces such that the density of matter is perfectly uniform on each slice (and that uniform can be characterized by the parameter Omega), unlike in the simple FLRW model where matter is assumed to be distributed in this perfectly uniform way.

--question 2 dealt with YOUR argument for an absolute truth about which points on separated twin's worldlines happened at the "same point on time" independent of any choice of coordinate system based on mere clock simultaneity (i.e. same actual p-time)--the argument with the labeled steps that you presented at https://groups.google.com/d/msg/everything-list/HeLo1QmdHFQ/XHyse24U_xIJ . I pointed out that I could come up with a seemingly exactly analogous argument that deals only with spatial positions (time is not involved in the argument at all, not clock-time and not p-time), with an analogue for each of the steps you wrote down, the purports to show there is an absolute truth about which point on different roads occur at the "same point in y" independent of any choice of coordinate system based on an arbitrary choice of x and y axes. If you'd like me to repeat this "analogous argument" in the same step-by-step manner as your argument for p-time simultaneity, I'd be happy to do so.

--question 3 was about YOUR claim that for every observer in the universe, "Every one of them is always currently in their own local actual time, their present moment." I was asking whether you meant that there is a single point on each observer's worldine that is "their own local actual time", or whether you were just saying that at each point on the observer's worldline, the version of the observer at that age has a different definition of "their own local actual time", without saying anything one way or another about whether all these different ages and their definitions are equally real. If you mean the first one, I was also asking whether this was an essential assumption in the argument with the labeled steps that I linked to above in the question 2 summary--if it is then your argument for absolute p-time simultaneity is completely circular, since you are assuming p-time from the start.

 

These have nothing to do with the concept of a present moment independent of clock time within which clock times run at different rates.

You need to understand the distinction.

I understand the distinction perfectly, if you think I am confusing them you simply haven't understood (or read carefully enough) my posts to you. While I recognize the notion of an absolute time distinct from clock time as a logical possibility, I don't see any compelling NEED to assume such a thing, and my second two questions above are questioning your own arguments for the NEED for a "present moment independent of clock time". Question #1 is about whether you would have any EMPIRICAL way to define absolute p-time simultaneity (given that you can't just define it in terms of 3D slices where the density of matter is perfectly uniform within each slice, as you might in an ideal FLRW universe), or whether you just take it on faith that there's a truth about absolute simultaneity even if there's no empirical way to decide what it is.

 

Refer to my 2 thought experiments of a day ago. 1. The billion twins example. 2. The all observers in the universe example. 

I did refer to the post where you presented these thought experiments, question #2 that I wanted you to respond to was from my own detailed response at https://groups.google.com/d/msg/everything-list/HeLo1QmdHFQ/Mw8jXkmytGoJ which you never bothered to respond to. Again, I showed that one could come up with a perfectly analogous argument in 2D space involving roads that diverge and later converge (three roads, a billion roads, all the roads in the entire infinite 2D space, it doesn't matter), which purports to show that there must be an absolute truth about which points on separated roads are at the "same point in y". Since this conclusion seems obviously silly, it indicates that the argument is flawed (a reductio ad absurdum). Again, if you didn't follow that analogous argument I can restate it or answer questions about it, but so far you have just blatantly ignored the argument altogether.

 

However these won't do you any good until you understand and accept the basic well established FACT that the clock times of the twins differ in the exact same present moment they both share.

The clock times differ when they are at the same point in spacetime (defined operationally in terms of them being able to send light to the other one and get the reflected light back in a negligible amount of their own clock time, with the light coming back showing the clock time of the other one). If you don't mean anything more by "the clock times of the twins differ in the exact same present moment they both share" than what I mean by "the clock times differ when they are at the same point in spacetime", then I agree with your FACT. If you do mean something more I'm not sure I agree, you would have to give me some operational definition of how they determine they are in the "same present moment" that goes beyond my operational definition of "same point in spacetime" above--unless you don't mean "same present moment" to be defined operationally at all, and are just assuming p-time from the start.

Jesse

[Jesse Mazer]

On Wed, Feb 5, 2014 at 10:53 AM, Edgar L. Owen <edga...@att.net> wrote:

Jesse,

A couple of points in response:

1. Even WITHOUT my present moment, the well established fact of a 4-d universe does NOT imply block time nor require it. Clock time still flows just fine in SR and GR.

I would agree that the 4D mathematics of relativity theory doesn't require the ontology of block time, though I don't see any alternative to block time besides some sort of "metaphysically preferred" definition of simultaneity (which wouldn't contradict relativity as long as long as this definition wasn't "preferred" by the measurable laws of physics). I don't know what you mean by "clock time still flows" in SR and GR--it only "flows" in the sense that its value is different at different points along a worldline, the same sense in which we could say that "distance from the end of the wire" flows along a piece of wire (i.e. the value of "distance from the end of the wire" is different at different points along the wire).

 

No clock time simultaneity of distant (relativistic is a better descriptor) events does NOT imply time is not flowing at those events. This is quite clear. It's a fundamental assumption of relativity that time flows.

What mathematical element of relativity corresponds to your notion of "flow"?

 

In fact relativity itself conclusively falsifies block time as it requires everything to be at one and only one point in clock time due to the fact that everything always travels at the speed of light through spacetime. I find it baffling that so many can't grasp this simple fact.

Huh? "Everything moves at the speed of light through spacetime" is not how most physicists would describe relativity, and those few who do are just speaking in a colorful way about the magnitude of the 4-velocity always being equal to c. And the 4-velocity is just defined as a vector whose components give you the rate of change of the spacetime coordinates t,x,y,z relative to proper time. 

Nothing about this notion is contrary to the notion of block time--as an analogy, if we have a piece of wire embedded in a block of ice and forming some type of curved shape, and we use an x,y,z coordinate system to describe different points within the block and on the wire, then at every point along the wire we can define a vector whose components give the rate of change of x, y, z coordinates relative to "proper length" at each point (where "proper length" refers to the distance between that point and the end of the wire--or some point along the wire marked "0"--as measured along the the wire itself). And in fact it's not hard to show (I can give you the derivation if you like) that using these purely spatial definitions, the magnitude of *this* vector must always be 1 at every point on the wire, regardless of the shape of the wire. Would you describe this situation by saying "every wire-point moves at the same speed through the block of ice", even though we are talking about wires that from our point of view are completely static, frozen in a particular shape within the block?

 

2. You complain about me not answering a few of your questions. As I've explained before I have limited time to post here because running my business keeps me very busy.

And please note that a lot of my posts have received NO answers at all either, e.g.

a. Several major posts, some as new topics, on my theory of how spacetime emerges from quantum events. Apparently this has just sailed over everyone's heads with not a single meaningful comment, not even any negative ones which is pretty surprising among this crowd! Apparently no one is interested in understanding the nature of time at the quantum level?

b. My post on a solution to Newton's Bucket. Also no relevant responses.

c. Several thought experiments lending very strong support to my present moment theory, posted just a couple days ago. Again zero response. And weren't those directed to YOU?

d. Several thought experiments designed to dig into the fine points of various aspects of time dilation. Again only a vague comment or two on 'asymmetry' but zero actual analysis of the points I raised.

e. Several other new topics on basic issues of science and epistemology. Again no relevant responses.

Those posts were not part of an ongoing discussion with *me*, though. I'm not asking you to respond to every argument I make, just to respond to posts that are part of ongoing discussions with you, in which I raise serious difficulties with arguments you have presented to me. And I don't mind if you take your time in getting back to me, but it is rather suspicious when you continually ignore my requests to address specific issues I've raised with you, even when you do apparently have time to respond to other posts of mine. 

 

As for your comment that "you have no idea what moving in clock time could mean" pull your head out of your physics books and watch your watch for a little while and see if the hands are moving. If not, you are in block time.

So does your argument for "movement in clock time" depend on our conscious perceptions, rather than any sort of well-defined quantitative measurements? It's not obvious to me that my perception of movement is anything more than a mental comparison between what I'm seeing now and my very short-term memory of what I was seeing half a second or less earlier...and of course the idea of comparing memories or other records with current observations still makes perfect sense in a block time view. 

I am interested in the issue of the difference between conscious perceptions ("qualia" as philosophers refer to them) and objective physical facts, and I have considered the possibility that if there is a "theory of consciousness" of the type that the philosopher David Chalmers discusses, then perhaps the "flow of time" would play a more fundamental role there than it does in physics. But I don't see that this implies any *unique* subjective present--if I can imagine a multiverse where different versions of me are having different experiences, I can equally well imagine that there are different mes-at-different-ages having distinct experiences, each of them experiencing their own "flow" of time...it'd be a bit like a series of TV screens which are each playing the same movie, but where each screen is one frame ahead of the screen to its left, so screens at sufficiently far-apart positions can be showing completely different parts of the movie.

Jesse

[Edgar L. Owen]

Jesse,

No. 

Question 1. assumes a cosmological model I don't and slicing 4d spacetime is what people do with spaceCLOCKtime, not p-time.

2. The spatial positions analogy doesn't work if I understand it because space is part of 4-dimensional spaceCLOCKtime. P time is an independent overriding concept in which both space and clock time are computed. You seem to note that it's impossible to define an absolute spatial position for some event for all observers. That's basic relativity as I said, nothing to do with p-time.

3. There is an actual present moment in p-time at which every observer is. He's not at every point on his p-time worldline. Look around you and at your clock. Are you anywhere else than where you are in both time and space? Block time has no way to explain the apparent location at only one point in space and time because it claims you are at every point in your worldline. So why this one? Block time tries to mislead us that we are actually everywhere in our worldline but can't tell us why we observe ourselves only at this present moment in it. It claims that all your instants also think the same thing but can't tell us why the you that you experience yourself as being is the one that is talking to us....

Yes, there is a compelling necessity to assume an independent p-time to explain how 2 different clocktimes can be at the same point in an actual present moment in the same actual time but different clock times. You just don't see this..

Re your last paragraph, then we DO agree (and your note that that is measurable and confirmable by the zero light distance between them is a good one). You just don't seem to realize the implications of what you are agreeing to.

Once you accept this the billion twins argument and the all observers in the universe argument follow to prove this present moment is common and universal.

Edgar