Fundamentally, is there only ‘spacetime’?

[A.C.E]

Hello all,

I’ll plunge naked straight into the deep end… 

Objectivist metaphysics is entity-centric: there’s the ‘stuff’ which makes up the universe (whether thought of as discrete particles or a continuous fluctuating field) as well as space and time as natural correlations (the relations between all this ‘stuff’). 

This is the correct metaphysical starting point and thus fitting basis upon which to build physics — so far so good? 

However, what if the most fundamental stuff/entities of the universe (whether fermions/bosons, aether, force-fields) could in turn be comprehensively described in terms of dynamic differences in ‘spacetime’ (put super-simply as relatively ‘thicker/slower zones’ interacting with ‘thinner/faster zones’) — that is, might entities be part-and-parcel of space+time rather than ‘a separate ingredient’ so-to-speak?  

I’m posting the question here (rather than the metaphysics forum) because I came across a physics-heavy theory which, if true, would possibly rule such a notion in — apropos a free-to-download book by a certain John A. Macken entitled The Universe is Only Spacetime.
(http://onlyspacetime.com) 

I fully confess that I don’t have anywhere near the competence to judge his argument, so I’d welcome any appraisal from Objectivists with a physics bent.

 

Anyway, my physics question on the status of ‘spacetime’…
Is the door open to describing everything in the universe solely in terms of space + time (reifying ‘spacetime’ processes) — or ought physics always be couched around a ‘primacy of entity’ come-what-may (with ‘spacetime’ a mere correlation)? 

  

[StrictlyLogical]

Philosophy is not physics.

Physics is a specialized science which builds on philosophy, philosophy does not deal with physics, it is the foundation of physics.

With respect to philosophy, it deals with all existents.  You can differentiate between entities, actions, and relationships, properties, attributes etc but philosophy fundamentally does not hinge upon which things fall into what, but it serves you to correctly identify them.

IF space and time ARE merely relationships between entities, then to deal with it correctly you need to scientifically show this.  Even if a philosophy provisionally conjectures something about it, unless it is fundamental to it, it is incidental… within the special sciences.  

BUT one must be careful to understand what philosophically speaking an entity is versus a relationship in order to correctly assess something in reality via experimentation.  

What characteristics do entities have in the broadest sense?  Does space time AS SUCH qualify?

 

…

 

Rather than leaving this entirely as a Socratic exercise, recall that an entity’s nature IS separately distinct and independent from anything else in the universe.  What makes THIS water molecule a water molecule does not depend upon where it is, what is near it, what is interacting with it, what is affecting it in any way.  In FACT the MORE you isolate the water molecule (reduce any interactions, causation, etc. with all other EXISTENTS), the more it simply SITS there AS a water molecule.  (of course philosophically speaking it always is a water molecule when interacting or not, but my point is about seeing clearly that it is an entity rather than an action or interaction or relationship)

Now, isolate a portion of space-time in the same philosophical sense… AS an entity… then describe it.

 

[EC1]

Yes. It’s what literally everything is build from.

[MisterSwig]

5 hours ago, A.C.E. said:

However, what if the most fundamental stuff/entities of the universe (whether fermions/bosons, aether, force-fields) could in turn be comprehensively described in terms of dynamic differences in ‘spacetime’ (put super-simply as relatively ‘thicker/slower zones’ interacting with ‘thinner/faster zones’) — that is, might entities be part-and-parcel of space+time rather than ‘a separate ingredient’ so-to-speak?

What exactly would be thicker and thinner, slower and faster? Zones of what? These concepts depend on the existence of stuff. How else will you measure size and speed?

[A.C.E]

Thank you StrictlyLogical, EC, MisterSwig.

I’ll use this post just to clarify my question + solicit feedback on Macken’s booklet specifically (StrictlyLogical actually merits it’s own supplementary reply). 


spacetime doing its stuff

 

Macken argues that the universe can be reduced to only spacetime. 

It certainly sounded absurd to me off the bat — surely ‘spacetime’ is just a coupling of space/time dimensions: twin relational existents that ‘require’ absolute existents (entities) in order to exist (as relations to) in the first place.

But the booklet’s title intrigued me enough to download his PDF and skim through.

I was relieved that it didn’t seem to be the usual pseudoscience. Indeed, it left me questioning my schoolboy assumptions about ‘spacetime’ (purposely written as a whole word, not hyphenated). Spacetime, rather than just an amalgam of space plus time, takes on a more-than-the-sum-of-its-parts peculiarity — peculiar enough, perhaps, for reification to occur ‘out-of’ space + time. Macken isn’t using spacetime as mere mathematical model but as the universal propagator of actual ‘stuff’ — a profoundly more economical version of ‘aether’ if you like. 

 

Now, for what it’s worth, I currently have a super-duper-dumbed-down way in which I’m able to envisage entity as a product of spacetime, which hopefully goes a little way towards addressing MisterSwig’s pivotal “of what” point. It is this:

basic entities are the relatively ‘thicker’ parts of spacetime (equally and crucially the ‘slower-to-pass-through’ zones). The attribute of thickness/thinness is as much temporal as spacial. For basal entities, the attribute of spacetime thickness effectively is the thing — spacetime thickness = thingness. These basal entities are in dynamic relationships with the relatively ‘thinner/faster’ zones; these localized variations entail ‘attraction/repulsion’ with their spacetime surrounds and a cascade of further forces and unfolding complexities — all issuing from thick/thin | fast/slow differences within spacetime. 

Now where’s my Nobel prize? 

 

Oh I expect that there’s plenty to take issue with here! But please have a peruse at Macken’s physics-rich reasoning rather than my own slapdash simplification.

The aim of this thread is to probe whether the idea ‘everything is only spacetime’ is feasible, somewhat flawed or a complete non-starter. 

[SpookyKitty]

I’m sorry but this seems to just be a very clever restatement of General Relativity.

[Doug_Morris]

I took a quick peek at the link and got the answer to my first question.  Macken definitely talks about quantum phenomena.  In addition, he says “However, even quantum mechanics does not give a precise description of the properties of the energetic vacuum on the scale of Planck length (~10^-35 m). Characterizing the vacuum on this scale is required to show how 4 dimensional spacetime can be the single component building block of everything in the universe.”  I haven’t dug any deeper yet.

[Grames]

On 4/2/2019 at 8:01 AM, A.C.E. said:

Anyway, my physics question on the status of ‘spacetime’…
Is the door open to describing everything in the universe solely in terms of space + time (reifying ‘spacetime’ processes) — or ought physics always be couched around a ‘primacy of entity’ come-what-may (with ‘spacetime’ a mere correlation)? 

The door is open to where ever the evidence leads us.  But the evidence and the methods used to gather that evidence must be valid, and the resulting conclusions must still lead back to and be compatible with the starting point of unaided human perception.  Identity and non-contradiction must apply at all scales, but it would be naive (and technically a reliance on the primacy of consciousness premise) to insist everything must be discrete entities all the way down. 

No comment on the theory you asked about, other than to note there is a seemingly opposite theory that spacetime is the result of quantum entanglement of everything with everything else.  Objectivism or any true philosophy could be compatible with either one because modern scientific ontology is such a distant abstraction in relation to human action.

[Boydstun]

First Earth-Based Radio-Wave Image of Galactic Black Hole (4/10/19)

In general relativity, including in its combine with quantum field theory at the event horizon of a black hole (Hawking radiation), mass-energy is one thing and spacetime with all its curvatures is another thing. Mass-energy is an entity. Distribution of mass-energy in spacetime determines how spacetime will curve. A thing susceptible to such a dynamics is an entity, I’d say, or at least it is some sort of concrete existent. So I think of spacetime—even empty spacetime, i.e., even spacetime if it had no vacuum energy—as an entity. Spacetime curvature is a causal factor in how mass-energy moves. This too supports the classification of physical spacetime as an entity.

In talking of entity and of concrete existent, I’m talking of some philosophical, metaphysical categories, specifically some categories in Ayn Rand’s metaphysical scheme. That sort of broad framework is useful for assimilating and keeping somewhat unified all the areas of one’s experience and learning. Methods of successful science are in part from rational philosophy (rational epistemology) down the ages as the discipline of philosophy assimilated and analyzed such success in science and mathematics as had been attained. However, in the mature sciences such as modern relativity physics, astrophysics, and astronomy, additional methods for success have also been forged by some scientists themselves (under their epistemology thinking cap, we might say) as they hunted what is in nature.

.

[StrictlyLogical]

4 hours ago, Boydstun said:

First Earth-Based Radio-Wave Image of Galactic Black Hole (4/10/19)

In general relativity, including in its combine with quantum field theory at the event horizon of a black hole (Hawking radiation), mass-energy is one thing and spacetime with all its curvatures is another thing. Mass-energy is an entity. Distribution of mass-energy in spacetime determines how spacetime will curve. A thing susceptible to such a dynamics is an entity, I’d say, or at least it is some sort of concrete existent. So I think of spacetime—even empty spacetime, i.e., even spacetime if it had no vacuum energy—as an entity. Spacetime curvature is a causal factor in how mass-energy moves. This too supports the classification of physical spacetime as an entity.

In talking of entity and of concrete existent, I’m talking of some philosophical, metaphysical categories, specifically some categories in Ayn Rand’s metaphysical scheme. That sort of broad framework is useful for assimilating and keeping somewhat unified all the areas of one’s experience and learning. Methods of successful science are in part from rational philosophy (rational epistemology) down the ages as the discipline of philosophy assimilated and analyzed such success in science and mathematics as had been attained. However, in the mature sciences such as modern relativity physics, astrophysics, and astronomy, additional methods for success have also been forged by some scientists themselves (under their epistemology thinking cap, we might say) as they hunted what is in nature.

.

Using Rand’s razor, spacetime as a separate entity is an unnecessary concept which can be let go.  Conceiving of a curvature of spacetime as a causal relationship is preferable.

1.  Spacetime has a curvature at any one point only as a consequence of its relationship to the mass and energy distribution (across time and space)  i.e. it is a property wholly dependent on other entities, and wholly independent of the properties of any other spacetime point.

2.  The properties (i.e. curvature) of any Spacetime point only affect other entities located at that spacetime point and only when they are there.  Spacetime points affect nothing anywhere else, including the rest of spacetime.

So

 

IF and only IF an entity A is at point X of spacetime is it affected by the curvature of spacetime only of point X, which spacetime at point X is affected by and only by the relationship of that spacetime point X with other entities (mass/energy distribution) across space and time.

Entity -> affected by Spacetime -> spacetime defined by relationship to other entities.

One can see that spacetime can be easily be rolled back (from reification) and conceived as part of a direct relationship between the entity and the other entities.

This reduces to entity A at spacetime point X is affected by other entities  (which effect can be expressed as a curvature in spacetime) by its relationship to them across space and time (mass/energy distribution). 

 

EDIT:  Recall, what does it mean, in concrete terms, to measure the curvature of spacetime at point X?  It means IF we put some thing (other than spacetime itself…) at the spacetime point X it will act in a certain way… that certain way is determined by the relationship of that point to the rest of the universe (mass/energy over time and space).

[merjet]

The Smithsonian Channel will have a show about black holes tomorrow, April 12, at 9:00 PM Eastern (link).

[Boydstun]

SL,

I don’t think that Rand’s character of categories requires that all concrete existents belong to one of those four categories and not to the other three. Those four are entity, action, attribute, and relationship. Firstly, one could take angular momentum, for example, to be truly an action but also an attribute, and a relation. Her way with categories is simply different than Aristotle’s way of absolutely unique categorization of a thing. (Please, anyone, correct me if I’m wrong about that point on Aristotle.) But secondly, and pertinent to the spacetime/mass-energy characterizations into Rand’s categories, it has seemed to me that anytime a concrete existent is understood as a system, one can rightly take it as an entity. For example, in AS 1016, Rand takes the solar system to be an entity. One could also take it as “this particular matter with such-and-such orbital angular momentum about the sun, also this other particular matter with such-and-such other orbital angular momentum about the sun, also . . .” Then we’ve a summation of actions of entities, not an entity. I’m comfortable with that sort of multiple categorization of a thing where it is true to a thing.

So I’d think it fine to take spacetime in its global structures to be an entity even if locally it were not an entity, but a relationship. And in GR we’d take this room I’m in to be, over very short, shorter, . . . periods of time, as asymptotically an inertial frame of motion. I’m fine with taking the space contained by these walls and containing me as not only an entity containing other sorts of entities, and the spacetime entity I’ve here as asymptotically of zero curvature; but as well, as a collection of a certain kind of relationships between other sorts of entities.

Probably the most important multiplicity of category that Rand employed was the ontological status of mind. As an operating system, an instrumentation and control system, it’s an entity. But it’s also a process and activity, that is, it falls in the category action.

The utility of Rand’s categories seem somewhat like the utility of a certain easy network understanding of a thing, a hand-over-hand sort of comprehension of a thing (although this easy network is an alternation staying outside entity): “A pear is a kind of fruit which is a part of a pear tree which is a kind of plant which (with others) is a part of the biosphere.” (30)

None of this entails, I should mention, that entity is a category not having primacy over other categories of existents, primacy in acquisition of language, in conceptual dependencies, and in ontological relations.

[I notice that Kant’s categories do seem to require no dual memberships. Perhaps that is because they are lifted from distinct logical forms of judgment. The latter could reflect basic ontological standings (contrary to Kant’s conception of their ultimate source and justification). Kant’s categories seem, however, less readily useful than a freer and more accessible set of categories such as Rand’s.]

[StrictlyLogical]

1 hour ago, Boydstun said:

SL,

I don’t think that Rand’s character of categories requires that all concrete existents belong to one of those four categories and not to the other three. Those four are entity, action, attribute, and relationship. Firstly, one could take angular momentum, for example, to be truly an action but also an attribute, and a relation. Her way with categories is simply different than Aristotle’s way of absolutely unique categorization of a thing. (Please, anyone, correct me if I’m wrong about that point on Aristotle.) But secondly, and pertinent to the spacetime/mass-energy characterizations into Rand’s categories, it has seemed to me that anytime a concrete existent is understood as a system, one can rightly take it as an entity. For example, in AS 1016, Rand takes the solar system to be an entity. One could also take it as “this particular matter with such-and-such orbital angular momentum about the sun, also this other particular matter with such-and-such other orbital angular momentum about the sun, also . . .” Then we’ve a summation of actions of entities, not an entity. I’m comfortable with that sort of multiple categorization of a thing where it is true to a thing.

So I’d think it fine to take spacetime in its global structures to be an entity even if locally it were not an entity, but a relationship. And in GR we’d take this room I’m in to be, over very short, shorter, . . . periods of time, as asymptotically an inertial frame of motion. I’m fine with taking the space contained by these walls and containing me as not only an entity containing other sorts of entities, and the spacetime entity I’ve here as asymptotically of zero curvature; but as well, as a collection of a certain kind of relationships between other sorts of entities.

Probably the most important multiplicity of category that Rand employed was the ontological status of mind. As an operating system, an instrumentation and control system, it’s an entity. But it’s also a process and activity, that is, it falls in the category action.

The utility of Rand’s categories seem somewhat like the utility of a certain easy network understanding of a thing, a hand-over-hand sort of comprehension of a thing (although this easy network is an alternation staying outside entity “A pear is a kind of fruit which is a part of a pear tree which is a kind of plant which (with others) is a part of the biosphere.” (30)

None of this entails, I should mention, that entity is a category not having primacy over other categories of existents, primacy in acquisition of language, in conceptual dependencies, and in ontological relations.

[I notice that Kant’s categories do seem to require no dual memberships. Perhaps that is because they are lifted from distinct logical forms of judgment. The latter could reflect basic ontological standings (contrary to Kant’s conception of their ultimate source and justification). Kant’s categories seem, however, less readily useful than a freer and more accessible set of categories such as Rand’s.]

Well put.  I only observe that the existence of some kinds of existents is mostly independent of other existents while the existence of other kinds of existents depends upon the existence of others.  This kind of consideration distinguishes entities.

 A relationship such as spacetime is an existent wholly dependent on every other entity (possessing mass / energy… by the way how many entities other than spacetime wholly lack mass and energy?) and is more of a property of a system of entities than an entity itself.

IMHO

[MisterSwig]

On 4/6/2019 at 3:07 AM, A.C.E. said:

Macken argues that the universe can be reduced to only spacetime.

I took a look at his introductory paper. The equations are well beyond me, so I have nothing to offer in that regard. However, you say he argues “that the universe can be reduced to only spacetime.” If you’re speaking loosely, then I get what you’re saying. But, literally, I don’t think that’s the case. Isn’t he starting with a huge assumption of “a sea of dipole waves” that make up spacetime, and then showing how these waves produce everything we see in the universe? This isn’t reduction. It’s imagination, from the bottom up. I’m not saying his theory must be wrong. Just that he’s not engaged in reduction. Please correct me if I’m misunderstanding.

On the dipole waves, themselves: are these waves “caused by transitions in a dipole”? If so, what causes the transitions? I had to look up this concept, so forgive me if I’m asking stupid questions. If a dipole is “a pair of equal and oppositely charged or magnetized poles separated by a distance,” then how are they charged or magnetized? It seems like the motion of the dipole wave depends on a force that initially charges or magnetizes its poles. Isn’t that impossible, if all that exists are the waves? Is it safe to assume that this electromagnetic property is intrinsic to and uncaused in the wave?

Also, this “sea of dipole waves” idea has me wondering how waves can uniformly fill space, so that we have no areas with nothing. And this is a problem I have with any theory that posits “something” as the base of reality. How do you distinguish one dipole wave from another, if there is no space between them or within them? This question is not answered in the paper. In fact, he says that dipole waves cannot be detected.  

[A.C.E]

Thank you SpookyKitty, Doug Morris, Grames, Boydstun, StrictlyLogical, merjet, MisterSwig.

 

Sorry for the delay. Here I’ll address the key questions that came up as well as try and steer the conversation back towards the nub of John A. Macken’s book The Universe is Only Spacetime (http://onlyspacetime.com).  

 

MisterSwig  
Yes I was speaking in an awfully loose way when I said Macken argues that the universe can be “reduced” to only spacetime. Not a literal reduction, just that all manifest complexities of the universe/existence could be ‘built out of’ spacetime alone. 

Regarding dipole waves: he is indeed working with a huge assumption that dipole waves exist on the as yet imperceptible QM scale (accounting for ‘the uncertainty principle’) — but he’s up front about where the assumptions reside within his theory. 
On the “space-filling nature” of these dipole waves: in physics waves are simply oscillations of (rather than within) ‘a field’ which doesn’t so much ‘fill the space’ but effectively defines space itself. One dipole wave can be distinguished from another despite ‘no gap’ between them in the same way we can discern a sea wave’s crests from its troughs. With less directly perceptible electromagnetic waves one needs to detect and establish the mean within a given wave frequency, then contrast this with the positive/negative variation in amplitude. There are no absolute gaps anywhere, ever, in my model. Furthermore, I take the crests (and/or the troughs) to be the basis for what we detect and grasp as ‘entities’ — those parts of spacetime that cross a certain amplitude threshold. 

SpookyKitty  
There is a quintessence difference between Macken’s theory and General Relativity. GR embraces additional ‘essential ingredients’; mass/energy + space/time, whereas Macken’s is just space/time. Moreover, Macken moots that his theory resolves the GR/quantum gravity conundrum, so I’d lodge that it represents more than a restatement of GR.  

Doug Morris  
I’m glad someone had a peek at the source material. Have you had a chance to delve deeper? Is Macken’s thinking sound in your opinion? 

 
Grames  
Lots to agree with here.
You draw attention to a seemingly opposite theory: spacetime itself ‘results from’ quantum entanglement. 

With this or Macken’s theory, there is an issue about what has fundamental primacy, what is the horse and what is the cart so to speak: is there a level/scale where carts and horses dissolve into false dichotomies within a greater whole?  

Anyway yes, let’s all work towards making scientific ontology relate back to good ol’ human graspability — metaphysics done the right-way-around. 

Boydstun  
Good, that was a pertinent underscoring of how current GR+QFT views mass-energy as separate from spacetime (curvature). 

Spacetime — full entity or mere existent? 
At first glance it might seem reasonable to promote (causal) spacetime to the title of relational ‘entity’ whilst the mass-energy part gets to be called ‘entity proper’ (or, to be constant, absolute entity). We can’t experience the workings of GR+QFT directly, yet it is graspable by thinking in more familiar terms of separable solidity (mass-energy) from a nonetheless existent and interactive ‘background’ of relational Minkowski spacetime. Could such an active conception of spacetime indeed be ‘an entity’ under an astrophysicist’s epistemological thinking cap? Mmmm…

Then follows an interesting back-and-forth with another rightly esteemed member of the forum, focusing on whether or not spacetime fits into the category ‘entity’…  

StrictlyLogical  

On 4/11/2019 at 6:16 PM, StrictlyLogical said:

Using Rand’s razor, spacetime as a separate entity is an unnecessary concept which can be let go.  Conceiving of a curvature of spacetime as a causal relationship is preferable.

(NB, the debate about the four categories being mutually exclusive or not is an exceedingly good one, but I see it as ancillary to the core focus of this thread — is the universe only spacetime? — so I’ll refrain from chipping in here.)

 

The upshot of this Boydstun–StrictlyLogical exchange is that SL reasons that spacetime curvature is (merely) a relational existent, not an entity. (I wonder if the awarded heart indicates that Boydstun accepts this or just admires SL’s argumentation?).  

But attention please: this categorisation of spacetime is based upon standard GR+QFT, is it not?

The point of Macken’s overhaul of GR+QFT effectively ‘dissolves’ mass-energy into spacetime (spacetime as energetic field). Space is a relational existent, so is time — but Macken’s spacetime is a generative dynamic for entities (mass-energy) and therefore his conception of spacetime would arguably be more than mere ‘relational existent’ — perhaps something  more akin to ‘existent/entity–process’ or ‘proto-entity’. 

Anyway, do you agree that Macken’s notion of spacetime is no longer adequately captured by the term ‘relational existent’? 

 

 

I love you all, so I’ll wind up…  
…in this conversation I see two main alternative choices for fundamental ontology of the universe…

 

1. GR+QFT: 

The universe = (mass-energy) entities (whether particles/waves/fields) 
+  
spacetime (as unavoidable corollary ~ the curvature of which is causal).

Or

2. Macken’s ‘disentangled’ GR+QFT: 

The universe (of mass-energy entities) = spacetime (space-time dynamics).

 

 

So, dear (meta-) physicists, which description fits best with what we now know?

 

[StrictlyLogical]

Unless and until the theory can be validated by observation /experiment evidence it stands only as mere speculation.  If his theory has any prediction different from existing  science then those could be tested… 

Fantasies can always be conjured from nothing (here quite literally) in order to “validate” the existence of the somethings we DO observe.  Things having possible attributes or properties can always be mentally inverted with a background of attribute or property having a propensity to manifest as a thing.  At least one error in this is the perceived motivation that things which are, need an explanation for their being.  That somehow nonexistence is coherent but existence is not… the premise is that things must at their base come from the nothing… because only “nothing” has explanatory power.

Here we see a mix of this exaltation of zero with a touch of monism (a very old and common tendency… “all things are water”).

 

[A.C.E]

Thank you StrictlyLogical, excellent ~ mulled over your reply for a week. 

As there are no other takers I’m penning this as a provisional epilogue. 

 

Fundamentally, is there only ‘spacetime’?  

This topic has not managed to tempt out the lurking physicists to engage with Macken’s own reasoning, so no clear-cut answers have surfaced as of yet. But it’s true that, prior to any such engagement, Rand’s Razor might be our most useful tool to scythes away the inept chaff from any remaining grains-of-truth: can ‘the spacetime universe’ concept defy its harshest swipes?   

Anyway, StrictlyLogical has provided at least five caveats regarding such a theory (as well as set up the wily Gravity Thread thread in which analogous errors of logic/conceptualization are picked apart).  

1. Is the theory testable? 
2. Is there a mental ‘inversion’ of entity attributes with a background attribute for reification purposes? 
3. Is there any notion that things-as-they-are need an explanation for their very being?
4. Does the theory ‘extol zero’ — ‘reducing’ everything to nothingness (of space, time)?
5. Is the theory an appeal to monism — only spacetime? 

 

I take these to be shrewd cautions rather than an outright committal of this theory to the flames (are they not SL?). 

Each concern should be duly heeded, yet I think most charges can be parried:

1. Yes — “how can this theory could be falsified” would be the first question to Macken (I have e-mailed him about this forum thread). 

2. On mental inversion…  

On 4/21/2019 at 3:23 PM, StrictlyLogical said:

Things having possible attributes or properties can always be mentally inverted with a background of attribute or property having a propensity to manifest as a thing.

This dips its toe into deeper metaphysical depths so I think it helps if I re-state/re-work it in my own words to ensure that we are talking about the same thing:

The definition of entity (and its attributes) is absolute existential independence; their existence owes nothing to what is external to them. 

(Echoes of my previous thread Ontology via Contrast. All I’ll venture here is to append that absolutes also entail relatedness (and vice-versa), and so the absolute independence of entity, although metaphysically definitional, nevertheless also remains relative to a context of external constraints). 

In the context at hand of ‘spacetime’ I think it would be a misreading of Macken to suppose he is arguing in favor of a ‘background’ for entities — his re-scripted definition of ‘spacetime’ already entails entities/energy — so there is no background attribute to ‘mentally invert’ entities out of. 

3. Macken’s theory seems to grapple with the actual mechanics of existence rather that seeking any ‘requisite underpinning’. Asking “how things work” is the more legitimate approach than “why things exist” (and the former might even eventually satisfy the latter question).

4. I think the charge of ‘extolment of zero’ fails to stick once Macken’s ‘spacetime’ is understood as anything but nothing.
   Btw, any theory advancing a balancing–out of something (like matter and anti-matter over greater spacial distances) would likewise not necessarily be extolling zero. It may just be an acclamation about physical equilibrium. 

5. Yes, somewhat, but any ‘ultimate explanation’ might unavoidably appear reductive if stated in a five word nutshell — the universe is only spacetime — ousting-out the integrated emergence of complexity. So I think the resulting ‘appeal to monism’ is the fault of an over-concise summarization of the theory rather than the theory itself (note that book’s subtitle already signals the interplay of anti-monist complexity: Particles, Fields and Forces Derived from the Simplest Starting Assumption).

NB, I take the terms ‘existence’, ‘the universe’ and ‘spacetime’ as being somewhat interchangeable. The statement ‘only existence exists’ also seems kinda monist, until it’s acknowledged that this One is also The Many. 

 

 

Rehabilitating the question  

I spy three presuppositions concealed within the original headline-grabbing question that might well have curbed an Objectivist’s enthusiasm:  

1. The word ‘fundamentally’ smuggles in the nefarious notion that existence is made up of a hierarchy of levels;
2. As outlined above, ‘only’ can be read as a crude reduction to monism;
3. Macken’s ‘spacetime’ requires a firmer contradistinction from its standard usage. 

An unpacking of these terms in my opening post would have been wiser, allowing the focus to be upon the validity or not of Macken’s physics. 
A re-vamped initial question might do the job:

Could the mechanics of the universe be adequately described using a dynamic conjunction of space and time — ‘Macken Spacetime’ — without referring (initially) to any extra ‘stuff’? 

 

P.S. 
Supplementary food for thought (a just dessert)…
…Are there actually only two relational existents (from which all other relations are derived): the spacial & the temporal? 

 

[Doug_Morris]

Gut reaction to that last food for thought: How would a romantic relationship fit in to that?

[A.C.E]

Haha Doug — I’d forgot to mention, love’s the third dimension!

[MisterSwig]

On 4/21/2019 at 3:35 AM, A.C.E. said:

One dipole wave can be distinguished from another despite ‘no gap’ between them in the same way we can discern a sea wave’s crests from its troughs.

I’m not satisfied with the analogy to ocean waves, whose motion is caused by an external force. Whereas the motion of dipole waves seems to be caused by an internal force. Also ocean waves move through a medium of water. Do dipole waves move through a medium? Isn’t the idea of motion dependent on the idea of a medium (water, air, space)? To have movement, there must be something in which that movement occurs. Otherwise, how do you distinguish movement from stillness? You have to be able to identify a change in position relative to the medium. Are dipole waves both their own medium and cause of motion?