This isn't implied, what is implied is that for a given equation of relativistic motion there is a space-time 'block' corresponding to its trajectory over space through time. It would be odd to consider space time an invariant block when the things within it can distort all of its motions with their particular properties.

I thought you would've quite liked this, special relativity produces a multiplicity of blocks and the Lorentz transform renders the blocks reconcilable. Which is to say, with a more ontological framing, the unfolding of the universe is relative to the trajectories of its localising elements - the differentials of movements - but the category of relativistic motion nevertheless has a clearly demarcated set of potentials. — fdrake

I never thought about it this way, and you're right, I really do like this. My first thought was to Deleuze's reading of Spinoza, in which he aims to "make substance turn upon the modes", rather than the other way around in which it's usually taken. And this too, is a kind of 'making space-time turn upon differentials of (localized) movement', rather than the other way around. I think then that my general sympathy with the Bergsonian interpretation comes out of the general self-interpretation of scientists - including and perhaps especially by Einstein - who drop the 'for a given equation of relativistic motion' qualifier and take SR as an approach to time tout court. This latter was, in any case, how I've always been thought to understand the ontology of time implied by SR.

I will try to have a more interesting and in depth response later if I can, but I'm still on holiday/traveling right now and I'm off to Vietnam in two days which is going to be even worse for me posting-wise, so I'll hedge and say here that I really appreciate the response (it's also 3am where I am right now so... :/ )

Agreed. Insofar as this article is criticising lazy metaphysics from physicists, I appreciate it. Insofar as it's shitting on relativity, I don't. But, the 'shitting on relativity' through thought experiments does show the need for lots of ontological work. Hence this thread. — fdrake

I don't have anything helpful to offer, but I'm downloading the paper and I'll read it.

It's a pretty interesting discussion piece. I don't particularly like the last two bits - essentially a rejection of the reality of time as described in special relativity, then qualia alongside some bollocks physics philosofiction. If you've not seen a paper distinguishing physical and experiential time before, I think you'd find that part interesting since you're a trained engineer. One thing the paper does interestingly with regard to the distinction between experiential and physical time is that it allows both to be mathematised - that is, considered in terms that are inspired or compatible with mathematical abstractions. That angle's rarely taken.

Insofar as it's shitting on relativity, — fdrake

Don't take it personally. Relativity shits on itself and clearly is on the way out as quantum information theories replace it and along with it, its weird ontology. No harm though. It just means the end of time travel. Relativity wasn't all that much to begin with other than it help create a pop hero for science.

Don't take it personally. Relativity shits on itself and clearly is on the way out as quantum information theories replace it and along with it, its weird ontology. No harm though. It just means the end of time travel. Relativity wasn't all that much to begin with other than it help create a pop hero for science. — Rich

fdrake specifically asked that people not participate in this discussion if they don't accept the basic premises he spelled out. Apparently you still feel the need to interrupt the discussion with your sniping.

Really? Read again. i never questioned the measurements. I never questioned the evidence. But you realize of course that science is going in a completely new direction, so science is itself questioning Relativity at both the micro and macro level, but that is a different story.

The thing is this, the OP is based upon a paper that questions Relativity's ontology which in turn is based you Bergson's Duration and Simultaneity which also questioned Relativity's ontology. So , the OP is all about questioning Relativity's ontology. I am merely agreeing.

This is also somewhat present in general relativity. Things like cosmic inflation - the expansion of distances neighbouring points in space - are modelled by making the space-time metric (metrics assign distances to pairs of points in space-time) a function of the time variable. This means that in GR the 'evolution of the universe' can be spoken of with respect to a universal time - which is exactly what they do in cosmology. — fdrake

By "somewhat present in general relativity", do you mean that the universal time is completely arbitrary?

Isn't the "universal present" explicitly contradictory to special relativity? So how would general relativity produce a universal present without contradicting the principles of special relativity?

Expansion of the universe shows up when the metric tensor has components which are an increasing function of proper time or proper distance depending on the formalisation. Duration and length may still expand and contract with respect to high speed motions, and the effects of curvature changes/expansion can still be relativised to the motion of a particle.

The trick to quantifying expansion is by looking at differential neighbourhoods of a point and relating differential changes to the metric tensor - when it is an increasing function of time, interpoint distances within differential neighbourhoods increase in time.

Rather than interpreting it as the physicists have no idea what they're doing and that 'the expansion of the universe' is indexed to a universal time then using that idea to derive contradictions in relativity: I'd prefer to keep the thread on the track of analysing the real ontological consequences of assuming its truth.

I know you're skeptical of relativity because you dislike how the relativisation of simultaneity interacts with your Aristotelian metaphysics (specifically the law of non-contradiction and its metaphysical background)- but why not take this thread as an opportunity to see what the assumption of it entails for thinking about space and time?

I'm really not interested in discussing whether it's true or not.

With regard to the block-universe that this thing seems to imply. The block universe is essentially conceiving of the vector space (x,y,z,t) as a space-time manifold - as if when all components were free to vary along their ranges, we have a continuous set of snapshots of all events. This isn't implied, what is implied is that for a given equation of relativistic motion there is a space-time 'block' corresponding to its trajectory over space through time. It would be odd to consider space time an invariant block when the things within it can distort all of its motions with their particular properties. — fdrake

Well, in block universe, there is no motion, just worldlines, straight (inertial) or otherwise. The dimensions of those worldlines can be different depending on the choice of coordinates, but that change (the separation (interval) of any two events, say the event of some twin's departure and the event of his return) is a fixed value, and not frame dependent.

Actually I don't see any ontological necessity from relativity theory. A 3D model of the universe works, despite the 4D Minkowski spacetime model that SR suggests. I did an advocatus diaboli piece about the universe being 3D, and the train-thought-experiment being considered in that light. It works in either model, and thus I find no ontological implications. One thing that I did find is that no inertial frame can be the correct one because no inertial frame foliates spacetime. So a curved foliation (not an accelerated frame) such as the comoving system may be a description of the ontology. I don't buy that, but I cannot disprove the view. The comoving frame functions locally as an inertial frame.

Expansion of the universe shows up when the metric tensor has components which are an increasing function of proper time or proper distance depending on the formalisation. — fdrake

But isn't "proper time" simply an arbitrary designation, dependent on some pragmatic principles? Wouldn't it be contradictory to the special theory of relativity to assume that "proper time" was something other than imaginary?

Rather than interpreting it as the physicists have no idea what they're doing and that 'the expansion of the universe' is indexed to a universal time then using that idea to derive contradictions in relativity: I'd prefer to keep the thread on the track of analysing the real ontological consequences of assuming its truth. — fdrake

Isn't this the most fundamental, and important ontological consequence of relativity, the nature of "the present"? We know the present as the division between past and future. And the way that we related to this division influences all practical procedures, it is how we relate to the world in our daily lives. If special relativity tells us that the division between past and future is just an illusion, then doesn't this make how we relate to the world illusory? What is the source of this illusion? Why would the living mind act to deceive us in this way, to create the illusion that the division between past and future is something real?

I'm really not interested in discussing whether it's true or not. — fdrake

It's hypocritical of you to say that you want to discuss the ontological consequences of the truth of relativity theory, then when I bring some up you act like "I don't want to discuss 'those' consequences"

Well, in block universe, there is no motion, just worldlines, straight (inertial) or otherwise. The dimensions of those worldlines can be different depending on the choice of coordinates, but that change (the separation (interval) of any two events, say the event of some twin's departure and the event of his return) is a fixed value, and not frame dependent.

I think it's strange to say that there's no motion in special relativity, considering the theory's topic is about what changes in motions that have speed close to the speed of light. In many respects it's what falls out of 'motion's speed cannot exceed c' and relative motions as equivalent to coordinate transforms. Further, if lengths contract and time dilates with respect to the movement of particles - which is an assumption of the OP, these are real effects that should inform the view of space and time.

A 3D model of the universe works, despite the 4D Minkowski spacetime model that SR suggests.

I really doubt this, since this trivialises space-time curvature. The Einstein and Riemann tensors are 4-tensors, and the metric derivatives and Christoffel Symbols they consist of interact to give 4 tensors., They need to maintain the number of indices they have so that they can be contracted through identification or multiplication by another tensor to derive the Einstein field equations. 4D space-time can't be removed from SR or GR without drastically changing their character.

But, if you have a reference or previous post on this, I'd be happy to read it.

But isn't "proper time" simply an arbitrary designation, dependent on some pragmatic principles? Wouldn't it be contradictory to the special theory of relativity to assume that "proper time" was something other than imaginary?

See rule 2.

It's hypocritical of you to say that you want to discuss the ontological consequences of the truth of relativity theory, then when I bring some up you act like "I don't want to discuss 'those' consequences"

Complete mischaracterisation, 'what does relativity do to the ontology of space and time if it's true?' is the point of the thread. I'm not going to engage with you in this thread any more unless you adopt the scenario. Find someone else to argue with. If you want to think of this thread as a facile children's playground with no import because SR is fundamentally flawed, be my guest, just go somewhere else, or engage with someone else, to do it.

One consequence of The Theory of General Relativity being true is that 95% of our universe is invisible dark matter, and dark energy. In my view, a rather novel idea to preserve General Relativity. Is dark energy and dark matter considered physical and within the providence of science?

https://science.nasa.gov/astrophysics/focus-areas/what-is-dark-energy

AFAIK dark matter is considered to be currently unobserved particles. Neutrinos used to be part of this before their measurement. AFAIK, there are loads of undiscovered and possibly unreal particles conjectured from different analysis in contemporary particle physics. It should be stressed that the amount of dark matter is a consequence of the models, not a (possibly temporary) epistemic limitation. In contrast to its composition, which AFAIK is still within the sphere of conjecture.

Similarly with dark energy, it's a part of contemporary physics, and the consequences of amounts of it are modelled. But with dark energy the amount is problematic, apparently some things predict there to be a lot more dark energy than there is.

In general, I don't know enough to comment here, other than providing a repudiation of claims that 'it's all nonsense look at dark energy and matter!', and that it's pointless to consider the effects of SR and GR on the ontology of space and time because dark matter and energy are too weird.

If you have anything about dark-matter or dark-energy that should matter in the substantive/procedural interpretation of space and time, give it a go. I'd ask, though, that you don't reduce space and time to cognitive structures, as if that would provide an account of how they work.

Just a general note: to categorise something as an illusion is pointless without trying to spell out why it is an illusion and how the illusion came to be; also how the illusion works. As if inscribing something in a mental or transcendental register removed the need to account for how it works.

I made some notes discussing this in terms of relativity.

GR and SR do have a single time direction in them, only it's a 'proper time' which is composed of differentials of time and differentials of space/the speed of light. That absolutely has a direction in both of them. If it was reversed, energies associated with masses and momenta can become negative. Proper time also tends to usual time when things are moving slowly relative to the speed of light in SR, and also when there's not much curvature in space in GR.

Material processes on earth - chemical, biological, behavioural - generally don't care so much that time is relativised -of the mapping from time to proper time-, since the frames they occur within don't have relative velocities approaching the speed of light. In these cases the Lorentz transform is effectively the identity transform - it does nothing; and the field equations of general relativity reduce to Newton's force laws (with tiny corrections that only show up if you're measuring things with a crazy amount of precision).

This is why differential equations describing transport of various chemicals around cells, or age related notions like 'age-cohorts' aren't perturbed by SR or GR - anything relativity has to say about them is so similar to what a 'universal time' would produce it becomes a difference that makes no difference.

The theories themselves reduce to usual Newtonian mechanics in low-speed low-curvature/mass scenarios. Luckily, this is the world we find ourselves in - most of the time - on Earth. And it is within this order of things that most processes unfold.

Usual conceptions of simultaneity still apply, usual conceptions of space still apply, for the majority of processes on Earth (on large enough length scales). The conception of simultaneity and invariant distances are not illusions in most scenarios, but they do produce transcendental illusions when applied outside of their scope. Special and general relativity are good descriptions of their target phenomena, empirically, and their influence cannot be removed by mistaking the subjective necessity (a-priority) of some antithetical concepts as the empirical failure of these theories.

Much better to see how things are and think about that, rather than begin from (what is purportedly) pure reason and constrain existence to its edicts.

All I did was point out one of the consequences if the truth of General Relativity, which is that 95% if the universe becomes invisible. As noted in the article, there are other problematic issues which may mean that General Relativity may need to be replaced (along with its ontology), but that aside, for the time being we do have to reconcile science with all of these invisible and unmeasurable forces that actually seem to be growing in size with new observations. Invisibility and illusions don't seem to me to be science.

Don't throw the baby out with the bathwater.

People have found things out about dark energy and dark matter. Neither the existence of dark matter nor dark energy are errors in physical theories, they are predictions. Where flaws or disagreements lay are in their properties - like the amount of dark energy and the particle-constitution of dark matter. When a better way of thinking about them or their constituents is discovered, it will become part of the scientific 'canon' you dislike so much. Their existences aren't illusions of the theory, Rich, they're very likely to be real - and that can be seen from the current state of the theories.

Completely inappropriate to characterise them as illusions. Also see rule 2.

. Neither the existence dark matter nor dark energy are errors in physical theories, they are prediction — fdrake

Until they are actually observed or measured, they are just plugins to rescue a theory, just as Vulcan was created to save Newton's theory. What happened was that the invisible planet of Vulcan was replaced by a 95% invisible universe. For the most part, in the history of science, plugins have usually indicated a completely new theory is necessary. Illusions even more so. In the case of General Relativity, very little is lost, which is why completely new approaches are being investigated, one's that do not rely on GR's ontology. What will be preserved in any approach is "gravity" whatever its ontology may be. I suspect it will involve quantum entanglement as opposed to geometrical spacetime.

I don't think you payed much attention to the link you gave me Rich. The presence of dark energy has implications for the cosmological constant.

One explanation for dark energy is that it is a property of space. Albert Einstein was the first person to realize that empty space is not nothing. Space has amazing properties, many of which are just beginning to be understood. The first property that Einstein discovered is that it is possible for more space to come into existence. Then one version of Einstein's gravity theory, the version that contains a cosmological constant, makes a second prediction: "empty space" can possess its own energy. Because this energy is a property of space itself, it would not be diluted as space expands. As more space comes into existence, more of this energy-of-space would appear. As a result, this form of energy would cause the universe to expand faster and faster. Unfortunately, no one understands why the cosmological constant should even be there, much less why it would have exactly the right value to cause the observed acceleration of the universe.

That there are unknowns on the frontiers of scientific research, especially when those flaws are known and researched by those researchers, is not just normal science functioning, it's close to being analytically true. These unknowns are linked to known things, and that set of relationships lets researchers tease out things from the unknown. Physics and cosmology are not yet degenerate research programs, and the puzzling nature of dark energy and dark matter are being researched in a manner consistent with normal science. Specifically here, afaik, attempting to study these phenomena in terms of different field theories or as consequences of the cosmological constant/metric term in the field equations.

No reason to think that they're degenerating, really. Since successive theories about them are still theoretically progressive (in the expansive form in this case), and there are competing research programs vying for 'the best account' of dark energy and matter. Normal science going on here. Dark energy and dark matter, far from being surface effects of scientific ignorance, are part of the core of scientific research in these areas.

You're not doing a very good job of pooping on science this time. So:

how do you think of space and time? How does relativity enter into it?

That there are unknowns on the frontiers of scientific research, especially when those flaws are known and researched by those researchers, is not just normal science functioning, it's close to being analytically true. — fdrake

Yes, in this case, we have replaced a theory (Newton's) which required an unknown planet, with a theory (GR) that requires a 95% universe. I have no problem with unknowns, as long as one represents it properly. Not only are the puzzling nature of a 95% unknown universe being investigating but so also is the theory that requires it (not a bad idea in my view). GR is actually not that sacrosanct especially since it isn't part of quantum theory. The nature of gravity of course is relevant to any science or ontology. Again, I believe the current target direction of quantum physicists, that gravitates around quantum entanglement will be very fruitful and ultimately space-time will be a relic of physics as was the fate of particles.

I don't poop science, I poop invisibility and illusions, the type magicians are involved with.

Are you asking me what I think of space-time as an ontology? I think it is invisible like the rest of the universe it created.

I would like to add to the paper referenced in the OP, these two videos created by the author of the paper, Stephen Robbins. I believe these represent his most current thoughts.

https://youtu.be/mcMnn5TpqT0
https://youtu.be/RjQg8on4yS0

They are each over 1.5 hours in length so quite difficult to summarize, especially since they are very dense in information.

Complete mischaracterisation, 'what does relativity do to the ontology of space and time if it's true?' is the point of the thread. I'm not going to engage with you in this thread any more unless you adopt the scenario. — fdrake

Look fdrake, either you're having difficulty understanding, or you're simply in denial of what relativity does to the ontology of time. Fundamental to the ontology of time is the distinction between past and future. This is how we derive the fundamental ontological categories of actual and potential, what has actually occurred, in the past, and what is possible, in the future. The boundary, which gives this distinction its ontological status, is called "the present", "now". From the assumption that the boundary is real, having ontological status, we conclude that the determinations of before and after also have ontological status.

Special relativity assumes that the determination of various events as past and future, or before and after, is dependent on the frame of reference, perspective dependent, "subjective". This is what relativity does to the ontology of time, it makes the distinction between the fundamental ontological categories, past and future, before and after, perspective dependent, i.e. subjective.

Do you understand what "ontology" is? It's the study of being, that which "is". Do you understand the temporal reference of "is", meaning "at the present"? If this is not the scenario you wish to adopt with your question of how relativity affects the ontology of time, then what is the scenario you wish to adopt?

Another consequence of GR, should we believe in its ontology,c is that the experience of life is an illusion, as described in the following article. So, we are to believe in invisible forces that comprised 95% of the universe that are guiding our lives in a block universe that is creating illusions of time. This deserves scrutiny, which is the objective of Stephen Robbins' papers and videos.

https://plus.maths.org/content/what-block-time

"From this block time perspective, time, as we experience in the block universe, is an illusion. "It's not a real, fundamental property of nature," says Cortês. The ticking of time, our experience of time passing, is only because we are stuck inside the block universe, moving forward along the dimension of time. "The fact that we experience moving forward in the block but not outside it comes from the fact that the block picture treats time just as another spatial dimension, and we can step outside of it. Time is not pervasive."

Here is another article from physical.org that questions time as conceived of in spacetime. If one is familiar with Bergson, as Stephen Robbins is, one can readily see how this new, non-GR view of space-time, including its resolution of Zeno's paradoxes fully conform to the author's point of view.

https://phys.org/news/2011-04-scientists-spacetime-dimension.html

The problem of the fixed block universe ontology of GR does not explain the nature of a quantum unfolding universe. Some if the issues are discussed here:

https://www.quantamagazine.org/a-debate-over-the-physics-of-time-20160719/

The ontological status of space-time as conceived of in GR is quite open to question.

The block universe is essentially conceiving of the vector space (x,y,z,t) as a space-time manifold - as if when all components were free to vary along their ranges, we have a continuous set of snapshots of all events. This isn't implied, what is implied is that for a given equation of relativistic motion there is a space-time 'block' corresponding to its trajectory over space through time. It would be odd to consider space time an invariant block when the things within it can distort all of its motions with their particular properties.

I thought you would've quite liked this, special relativity produces a multiplicity of blocks and the Lorentz transform renders the blocks reconcilable. Which is to say, with a more ontological framing, the unfolding of the universe is relative to the trajectories of its localising elements - the differentials of movements - but the category of relativistic motion nevertheless has a clearly demarcated set of potentials. — fdrake

I know I briefly addressed this exact passage in my post prior, but on further reflection, there's more to be said with respect to the question of time, which was what this discussion was motivated by. While I still do like this, I think this actually speaks quite nicely to Bergson's point here re: what I referred to as a desubstantialization of time: to the degree that every space-time block is relative to the trajectory of it's localising elements, what is missing or simply untheorized is precisely the passage from one trajectory to another. In other words what is missing, or rather, what is simply assumed is time itself. Time is 'given': given this space-time trajectory, that is the corresponding space-time block. But the passage of time itself is precisely what takes place 'before' (logically speaking) STR 'kicks in', as it were.

It's important to emphasise that this is not a 'fault' of STR. It speaks simply to its scope, and what kind of implications can be drawn from it. When I said that STR does not provide a substantial theory of time, this is what I was getting at. Time itself takes place 'behind it's back', as it were, and STR explores - in a totally legitimate way - what can be predicted given that fact of time's passage. But this passage itself does not fall within the scope of STR. One cannot draw a temporal ontology from it without losing the very thing it ought to account for: time.

--

The article linked by Rich above is actually quite fascinating to read in this regard (https://phys.org/news/2011-04-scientists-spacetime-dimension.html): It begins quite well by noting that "it’s more correct to imagine spacetime as four dimensions of space", and that "Minkowski space is not 3D + T, it is 4D". But from there, instead of concluding that, as a result, STR is simply silent on the question of time (i.e. it says nothing about it either way - which is the whole point of their own reconceptualisation!!), it infers instead that "the universe is “timeless” (!!!). It's basically a classic case of looking for the lost key under the streetlamp and, not finding it there, concluding that there was never any key to begin with. But what it 'wrong' here is not the theory - which in fact, the scientists have exactly right (insofar as they correctly recognise, perhaps more acutely than any before, that it's four dimensions of space at play) - but the implications drawn from it. Excellent science, abysmal philosophy.

I think this actually speaks quite nicely to Bergson's point here re: what I referred to as a desubstantialization of time: to the degree that every space-time block is relative to the trajectory of it's localising elements, what is missing or simply untheorized is precisely the passage from one trajectory to another. In other words what is missing, or rather, what is simply assumed is time itself. Time is 'given': given this space-time trajectory, that is the corresponding space-time block. But the passage of time itself is precisely what takes place 'before' (logically speaking) STR 'kicks in', as it were.

I find a lot to agree with, but I wanna place some extra emphasis on the strengths of the theory. I believe it is informative to a naturalistic metaphysics - at least insofar as it rules out various ontological postulates.

For probably the first time since the old PF, I'll be using my own idiosyncratic concepts a lot. So bear with me.

The only thing I find disagreeable in this is that passage from one trajectory to another is internalised through the equivalence principle. Say we consider two frames of reference whose equations of motion are given by sets F1 and F2, there is a relativised form wherein velocity is mapped to relative velocity, accelerations are mapped to relative accelerations and so on - these allow the translation of specific space time trajectories to one another.

I don't think this is a merely epistemic property of SR, I think it's essentially a statement of relational closure of motion in the regional ontology of SR. Will digress on relational closure to make some sense of it, as it's a term I use when thinking about things like this. Discussing what a regional ontology is will follow.

If someone believes in a transcendent God, they stand in a relation to that God. Specifically X believes that {some set of properties obtain about that God}. If it is really that transcendent God which is related to, how is possible for something 'exterior to being' in substantive senses or 'logically prior to it' in others to relate to any particular? The impossibility of this I term relational closure, relata are always existent in some commensurable way, and moreover there must be an overlap of the modes of being/becoming of the relata in the relation.

This is to say - different trajectories of motion in SR, whatever their sense of time - have common modes of expression, and specifically the relations in this case are the mapping of velocities to relative velocities and coordinate systems to others. There's no external 'space of trajectories' to go to for any regional ontology of SR. I don't mean 'SR gives a good account of aging' or 'SR gives an account which involves human reaction time' or anything to do with evolution, which have their own regionalised notions of time, just that trying to find a sort of movement which isn't described well by SR in its own terms is pretty hard, if not impossible. You can find examples by going close to very dense objects, however, and in these cases GR takes over.

For regional ontology, I refer to the specific mode of being of a designated class of phenomena. The only classes which can have regional ontologies devoted to them are ones with relational closure. I think this is similar to 'creating concepts on a plane of immanence' in Deleuze (or as it's thought of by Daniel Coffeen). Further, developing a regional ontology of a class of phenomena corresponds to the study of how it relates its subunits, and how those relations relate.

It's in this sense that coordinate transformations in SR are not just principles of relations of the objects in SR, they're also the means by which the relations are related. The generation of all of these relations for the regional ontology of SR comes from two principles, the cosmic speed limit of light and the equivalence between relative motion and (Lorentz) coordinate transformations (the equivalence principle). Everything follows from those building blocks.

That said, the passage of time can be said to be presumed in SR and GR insofar as it is primitive in the relations of SR and GR - it's a dimension of a vector space, which when combined with others (space) it produces/models the relativisation of time and space through the category of motion. Not simply in the sense that 'motion is space change over time' or that 'motion is change', but it effects the hows of both - motion as such, just as time as such is not part of the regional ontology.

One cannot draw a temporal ontology from it without losing the very thing it ought to account for: time.

In some senses, yes, in some senses no. Heidegger treats regional and fundamental ontology in a similar manner, attempting to ground regionalised things like moods and language in more primordial things like self-direction and the interpretive-as-structure. But I think this is an idealist way of looking at it - as if the ontology of Dasein was derived from but not conditioned by its ontic realisations. Similarly, SR does place a few constraints on what an ontology of space, time and motion should look like; how it deals with motion as such, time as such and space as such. By as such here I still mean in a somewhat constrained sense relating to physical properties and material flows.

(1) Time itself should be considered as something which can interact with its own unfolding, considering that motion may change its rate of unfolding.

(2) Space itself should be considered as something inseparable from time and vice versa, otherwise space-time curvature doesn't make sense.

(3) Motion itself should be considered as more than an analytic composite of time and space, since it effects the unfolding of its constitutive objects and itself. It is both a relational category of time and space as well as a phenomenon effecting both.

(1),(2),(3) together mark space,time and motion as of equivalent logical priority. Ontologies should treat them as distinct but inseparable.

There are also more specific conclusions that can be drawn:

(A) Time as such cannot be subordinated to a notion of event succession, since temporal orders of events are relativised to motion. The event-clock of the universe can be fickle.
(B) Space as such cannot be subordinated to extension, as time is implicated within it (and vice versa) and these things all change depending on what is analysed. There is a little wrinkle here in terms of treating time as an extensional dimension as well as an index of events, but axiomatically positing the two as the same is what happens when you make it a dimension of the space-time vector space.

Another thing relativity teaches us is that a different regional ontology is needed for the every-day. That is, non-relativistic thinking. We can't ignore the various limiting theorems that reduce GR to SR and SR to Newton. In this realm temporal order is preserved. Our technology can push us past scenarios of the every-day, however, but the effects of it are usually confined (like in the LHC) or very small (like clock differences on transpacific flights). In other words, we can't say that the ontology of GR and SR is a complete account of their contained concepts, even though there is a large region of overlap between their respective 'as such' categories and the theories. They do quite a lot to explain various phenomena in the universe, and so should be treated with respect within their zones of relevance.

Another big thing to note is that experiential time, and the relation of experiential time to physical time, are largely untouched by both.

I didn't make much of the 'timeless space' paper, I'm sure interesting things do happen when you discretise space to the nearest Plank length, but seeing time as a weird dimension of space has always been possible and even suggested by the consequences of treating it as an extensional dimension as well as an order of events. Einstein did this himself, it's a consequence of past-present-future being mucked with by the transforms. I don't think it's warranted to say 'this is all there is to say about time' on the basis of those theories, but I can see why someone would think time was illusory if 'the succession of events' has been destroyed.

I really doubt this, since this trivialises space-time curvature. The Einstein and Riemann tensors are 4-tensors, and the metric derivatives and Christoffel Symbols they consist of interact to give 4 tensors., They need to maintain the number of indices they have so that they can be contracted through identification or multiplication by another tensor to derive the Einstein field equations. 4D space-time can't be removed from SR or GR without drastically changing their character. — fdrake

It is certainly possible to interpret relativity in the context of a 3D world evolving through time. The only problem is that it isn't very elegant. For instance, the precursor to SR, the Lorentz Ether Theory, preserved our traditional notions of absolute time and space by introducing an undetectable ether (which you can probably guess is why it didn't catch on). Apart from that though, it was empirically equivalent to the theory, just with a preferred frame. In GR, the case is somewhat different (since there is no such thing as an inertial frame), but we can still introduce a preferred foliation if we want to. Of course, I'm not saying here that we should (since again this would be ad hoc), but only that we could.

I interpreted noAxioms as suggesting that it's possible to interpret things in a way that made 3 dimensions of space & time combined. Don't see much of a problem with there being different rates of development of phenomena depending on reference frame - that's just using the chain rule in calculus. IE, differentiating x by time in another frame would (dx/dT)(dT/dt).

Don't see much of a problem with there being different rates of development of phenomena depending on reference frame - that's just using the chain rule in calculus. IE, differentiating x by time in another frame would (dx/dT)(dT/dt). — fdrake

I wasn't referring to anything like that. I suppose what I'm trying to say is that relativity doesn't necessitate a 4D block universe. It is certainly possible for us to view time in the traditional sense, as a 3D world that changes via. the passage of time though there are costs to that sort of view.

GR's problem with time and quantum theory. If I've analyzes Ellis' new model, it can be seen that it v is much closer to Bergson and Robbins then it is to Einstein. He pretty much dissolves Einstein's deterministic universe.

http://discovermagazine.com/2015/june/18-tomorrow-never-was

"What’s most disarming about the block universe, remarks Ellis, is that unlike a movie that plays through a series of successive instants, there is no special point in time that all inhabitants would agree on as “now” — no unique marker that separates the fixed past from the open future."

"There’s more. Just as the students would disagree on whether the clock tower was to Ellis’ right or left, depending on where they stood, two people in Einstein’s block universe could even argue over the order in which events occurred. To one person, the Trinity clock might strike 2 p.m. before Ellis finished his last sip, and to another, the bell chimed only after he was done."

"In the block universe, then, what someone perceives as the future is what someone else saw as the past, depending on the person’s position and motion. Events that have yet to happen for one person, it appears, have already happened for another. The future, though it remains unknown to you, seems to be written already. ... Einstein himself described it thus: “People like us, who believe in physics, know that the distinction between past, present and future is only a stubbornly persistent illusion.”"

"Ellis’ new model .. argues that Einstein took that concept too far. There’s no need to assume that the fourth dimension must already exist out into infinity. Thus Ellis’ model has one crucial difference from Einstein’s: The future boundary does not encompass all that will ever happen.

"Thus Ellis’ model has one crucial difference from Einstein’s: The future boundary does not encompass all that will ever happen. Instead, the leading edge of space-time marks the “present” crawling outward, moment by moment, transforming tomorrow’s maybes into yesterday’s fixed happenings. “Tomorrow there will be one more day in the universe than there was today,” says Ellis. “The past is real and can have had an effect on us today, but the future cannot influence us because it does not yet exist.”"

" In Einstein’s view, these events — and all future events — coexist. But in Ellis’ picture, both events must lie in the portion of the evolving block that houses the past; they are fixed into reality before information about them reaches anyone. Similarly, in Ellis’ view, two observers can disagree on the duration of an event, but only if that event has already crystallized into the past."

"If Ellis is correct, how does he explain the mechanism that causes the front edge of the universe to push forward? “The surface is where the uncertainty of the future changes to the certainty of the past,” says Ellis. He found hope in another branch of physics, well known to physicists, where a transformation from uncertain possibilities observably becomes a fixed reality."

"Quantum experiments give Ellis the heart to believe that time is real and Einstein’s simple block universe is wrong. “Some physicists say that the future is already written into today, but I think that they are not taking quantum uncertainty seriously,” says Ellis. “Quantum uncertainty, to me, says the future is not determined until it’s happened.” He contends that at the front edge of his evolving block universe, the uncertain future crystallizes into the past through a sequence of microscopic quantum events. "

"And he scoffs that the burden of proof should lie not with him, but with those who claim that time is a mirage of our own making. After all, Ellis says, not only does his model gel with quantum experiments that appear to show that time is real, it also encapsulates our common sensations, “which is tested every day, by everyone, whenever anything happens.” Life itself is an experiment that backs his view.

"With this in mind, he quotes from the ancient Persian poet Omar Khayyam’s musings on the visceral difference between what has gone and what is yet to come: “The moving finger writes; and having writ, moves on: Nor all thy piety nor wit shall lure it back to cancel half a line, nor all thy tears wash out a word of it.” Then, with a guttural laugh, Ellis throws down a challenge to his critics: “If you don’t believe that, then you go back and change the past!”"