The ones at the edge will have the least elapsed time because those are accelerating the most. — noAxioms

Not quite. From the point of view of special relativity, as analysed with respect to an inertial frame, only the scalar speed along the tangent of the trajectory, and not the acceleration, is relevant to the ratio of time dilation of a moving clock. Of course, it's true in this case that the clocks located further away from the center of the disk are accelerating more (centripetally), but it's not because of that that they are running slower. It's just because of their higher scalar (tangential) speed.

The further away from the center of the rotating disk the clocks are, the most they will lag. This is in accordance with the familiar special relativity equation for the ratio of time dilation as a function of speed (dt = gamma*dt_0). That the trajectory is circular rather than linear is irrelevant to the applicability of this equation for a moving clock.

An interesting reference frame to consider, though, is the frame in which the disk is at rest and the rest of the world is rotating around its center. (But this is not an inertial frame and hence the Lorentz coordinate transformation equations don't apply to it.) It's a non-inertial frame in which a stationary observer slowly moving along the axis would measure a variable "pseudo-force" (the radial centrifugal force locally indistinguishable from a gravitational force) as well as a small lateral Coriolis force. It is due to this pseudo-gravitational force that such an observer would be able to explain why the clocks that are located closer to the center of the disk are running faster than the clocks that are located further away. They are effectively located higher up in a pseudo-gravitational field, and in accordance with general relativity, clocks down a gravitational well run slower than clocks higher up. (And due to the "principle of equivalence", a pseudo-gravitational force due to acceleration can't locally be distinguished from a "real" one due to gravitational attraction.)

OK thanks. Is it easy to convert the online book to PDF? — John

I found an online tool for that. Just PM me.

I'm interested to know what OCRing is... — John

Optical Character Recognition... to convert the raw images in the pdf files that I had generated into searchable text (that can also be underlined, highlighted, copied, etc.) I couldn't find a good freeware to do that, so I downloaded a 7-day trial version of Adobe Acrobat DC. Thus converted, the pdf book looks just the same but it now has a hidden text layer added to it.

I am going to use K. T. Fann's book Wittgenstein's Conception of Philosophy as a guide for much of my summary of the Tractatus, because I think it is one of the best summaries written on Wittgenstein's early and late philosophy. If you want to study Wittgenstein I would suggest getting Fann's book. You can get it on Alibris (used) for just a few dollars. — Sam26

Thanks for the recommendation. I noticed that Google Books makes the whole book available for online reading. (I grabbed it and OCRed it so that I could annotate it). This is strange since Google *also* makes available a free sample, and sell the whole book in the Books section of the Google Play Store.

Stumbled upon a great piece by Susan Haack — darthbarracuda

Yes, nice that's its freely available online. It's based on two lectures that you can also watch on YouTube.
Science, Yes; Scientism, No
Scientistic Philosophy, No; Scientific Philosophy, Yes

And also of interest: Six Signs of Scientism

Welcome back!

I remember that there was a very good thread on the older forum about Wittgenstein's Tractatus. Was that your thread? In any case, if you can repost the original post, and the date, it ought to be possible to find the old thread on the Wayback Machine.

That's fair. a "thick" present feels in line with my feelings about this theme. I wonder though, if the present reaches a sufficient 'thickness' is 'presentism' still a good name? — csalisbury

It isn't a bad name, it seems to me, if the idea that only the present exists from the perspective of an agent can be given a reasonable sense.

The sense in which the future doesn't yet exist is the sense in which future possibilities still are open from the present perspective of a powerful agent. It amounts to a negation of nomological determinism -- i.e. the idea that the historical past in conjunction with the laws of nature determines the future -- which is a premise that doesn't make sense from the standpoint of practical reasoning.

There also is a related sense in which the past doesn't exist. From the perspective of an agent, many opportunities pass by and the possibility of them being exploited become foreclosed. The past doesn't exist anymore in the sense that it has become settled history, forever beyond the reach of the powers of an agent to shape some of its aspects according to her will (though the past still 'exists' from her perspective in a different sense: as furnishing constraints on her present and future actions).

The present, then, exists in the sense that it consists in all the opportunities for one to engage one's agential powers in various ways: power/opportunity pairs which constitute possibilities that threaten to become foreclosed, but that are immediately relevant to practical deliberation. Since actualizing one's powers to exploit present opportunities (either through individual or collective action) is a process that typically takes time, and is thus described with the use of the progressive aspect of action verbs, this also accounts for the thickness of the present.

So then the concept of time is not needed for what mathematicians do, it becomes a question of frequency and repetition for them, not time. For the mathematician it is the manipulation of mathematical expressions in space? They don't try to capture the richness of the experience of a moment, only its basic abstraction. — Cavacava

This is not quite what I was arguing. I wasn't contrasting the language of pure mathematics with the language of ordinary experience. I was rather contrasting the language of mathematical physics, and of other so-called exact sciences, with the language that one must make use of in order to bring to bear physical laws (couched in terms of B Series -- universal law statements) to the results gathered from actual experimental setups (couched in terms of A Series -- actualizations of real powers). There has to occur a translation from claims reliant on a metaphysics of isolated 'event' (magnitudes of physical values at space-time locations) and Humean causation to claims reliant on a metaphysics of 'substances' (or 'continuants') and their powers in order that the former claims may become empirically meaningful (and hence objective).

The other conception of the B series is historical, what happened in a chronological or some other type of order, say cyclic, it seems to be more about time as we more commonly understand it.

It is a point of view that abstracts away from the identity relatons that hold between the temporal 'stages' of the powerful actors, and which seek to externalize or reduce their specific powers to universal laws of causation that hold between structureless events. It's a vain attempt to achieve a God's eye view on the empirical world.

So are you suggesting the B series is theoretically collapsible into the A series, probably no, but then where is the measure, how thick can a moment be before it is history? What separates the flow of time from its chronology. I don't think the experience of a moment can be separated into present, past and future, they stab too much into each other. — Cavacava

It's not so much that B Series reduce to A Series but rather that the conception of time involved in B Series descriptions of events abstract away (for mere purpose of universal generalization) from features of A Series that are essential to the understanding of time. Being abstracted away, they still remain in the background and must be appealed to when physical theories are brought to bear to particular experiences (i.e. the interpretation of singular experiments or the deployment of theories in pragmatic contexts). In other words, the mathematical apparatus of a physical theory can be couched entirely in the vocabulary of B Series alone (for instance as they formalize the universally quantified statements of the 'universal' laws of physics). But when this mathematical apparatus is brought to bear to singular experiments, then one single element in the B Series must be identified with "now" (i.e. coordinated with the present time of the experimenter) in order to acquire definite meaning and practical significance from the point of view of an embodied physicist. This is why A Series are more fundamental. They lay behind the interpretation of the abstract theories couched in terms of B Series.

Do you think that time's flow requires an individual self that can experience that flow. Seems as though there would have to be some point of reference to experience time as a flow if time's flowing is not an illusion or a physical limitation.

Yes, I think time flows only with reference to the perspective of an embodied living subject. This makes it subjective in a sense that isn't contrary to objectivity, but rather in a way that makes objective judgment possible. This is related to the Kantian idea that the categories of the understanding (subjective) must be brought to bear to intuitions in order that experience can be objectively valid. In the case of the experience of time, one's subjective location within the A Series (as occupying the present time) is a necessary condition for one being able to judge, objectively, that some future states of affair are within one's power to bring about while other states of affair already are settled and hence not within one's power to affect anymore. Subjectivity grounds objectivity.

The problem here is that GR would seem to support some form of eternalism. — Marchesk

I don't think GR supports eternalism anymore than the special theory of relativity (STR) does. One reason why STR can be taken to support eternalism over presentism is because there doesn't exist an objective criterion for singling out a unique concept of simultaneity, and hence a unique definition of a spatially extended present.

But a weak presentist, as opposed to a strong presentist (as I defined them very roughly in my earlier post with reference to Augustine and McTaggart) need not commit to the existence of a very thin present ('space-like surface') uniquely defined over vast spatial expanses (e.g. many light-years away). The weak presentist only must be able to single out the presently existing time with reference to her lived present (and local) pragmatic perspective. This perspective can also be joined to a shared intersubjective perspective through interactive conversation with others and the shared participation in collective projects.

All that is required from physics from a weak presentist perspective isn't a definition of the spatially extended present (stretching to infinity in all directions) but a distinction between those events that are entirely settled independently of the agents present powers (i.e. everything that isn't within one's 'future light cone'), those that aren't yet entirely settled regardless of what one has done in the past or is currently doing (i.e. everything that is within one's 'future light cone') and what is currently enmeshed into one's temporally thick present activity (one's pragmatically circumscribed space-time neighborhood).

Presentism is dumb because it wants to make everything happen at this very moment, but things don't happen at a moment. (When's the present? the current planck whatever? the current nanosecond? second? minute? doesn't experience itself happen over time? How long does it take neurons to fire?) — csalisbury

I think this objection only properly applies to some strong forms of presentism -- e.g. Augustinian "knife edge" presentism, maybe. Weaker forms of presentism (such as the presentism entailed by McTaggart's view that A-Series are more fundamental than B-Series) seem to me more plausible precisely because they don't assume any God's eye view of the 'flow of time', or of the thickness of the present. An A-Series can be comprised of yesterday, today and tomorrow. Today obviously is a thick present. If what is present is whatever can be synthesized in experience for purpose of empirical investigation or practical reasoning (e.g. assessment of present opportunities for action) then there is no a priori limit to how thick the present can be as it might be conceived to appear in the middle of some essentially subjective A-Series.

No, your tense is wrong. Do, not did. What I did yesterday existed, it impacted the present, but it no longer exists. The effects are still felt. — Hanover

Indeed, indeed!

Cool. So there could be no passage of time in a void. Picking a point in time is actually picking an event. The assignment of a temporal point says something about how our event is related to other events. Is that about all we can glean from Leibniz? — Mongrel

I don't know; I'm not familiar enough with Leibniz's metaphysics.

I wouldn't go as far as saying that picking a point in time is actually picking an event. (I assume you mean "event" to refer to something more substantive than what physicists call events: i.e. mere space-time points). But it does require there being a substantive framework (e.g. an actual set or rulers and clocks) relative to which temporal (as well as spatial) locations are defined.

Did we agree or disagree that Leibniz's argument for relative space works for relative time? — Mongrel

Yes, if what is being denied under the label "relative time" is the intelligibility of the idea of an absolute positioning of events in time, then the argument against the idea of an absolute positioning of events in space works just the same for time, it seems to me.

In the early, radiation-dominated universe gravitational collapse could not occur (because reasons). — SophistiCat

I assume you mean "(regional) gravitational collapse(s)" and not global collapse.

The universe then was close to a (local) thermodynamic equilibrium. If global expansion did not occur and the macro-state of the early universe persisted indefinitely, it would have remained a very uniform, hot "particle soup". The entropy then was close to its maximum value - which is why it seemed weird to me to characterize that state as "perfect order".

Yes. The maximum entropy of a system isn't supervenient on its actual macro- and micro-physical states but also on the boundary conditions since those conditions contribute to determining the number of micro-states that are available to the system.

But then, characterizing entropy in terms of order is generally misleading.

Following rapid non-equilibrium expansion and cooling additional entropy was created first by nucleogenesis and later by gravitational collapse.

This is rather akin to the emegence of systems characterized by new kinds of entities that enjoy newly created low-energy degrees of freedom as a result of phase-transition (in the direction of lower enthalpy; e.g. recombination, condensation, freezing, etc.) or the emergence of systems characterized by effective field theories. What is created insn't entropy, since those global/regional transitions are thermodynamically reversible (since adiabatic), but rather new "opportunities" for newly created entities (e.g. dissipative structures) to persist in time through thermalizing the high energy radiation that was created (together with the new cold sinks) by the transition process.

Under the worm-theory, those experiences of being at my computer are had as part of a larger experience which includes other times. — Mr Bee

I am not sure why the worm theorist ought to be committed to that. She is committed to the temporal stages of a person being parts of that person. Those stages add up mereologically to a worm and the person is numerically identical with this worm. But it doesn't follow that experiences had by that person at different stages make up a unified experience. Likewise, my organs and limbs are part of me. But it doesn't follow that my organs are part of a unique super-organ or that my limbs are part of a super-limb. It is the stages of the subject of the experiences that are parts of the whole person (i.e. worm) according to worm theory, not necessarily the experiences themselves.

Here is another way to put the point. Having an experience is tantamount to one being in cognitive contact with some determinate aspect of one's perceptible environment (in such a way that the elements of this experiences display a synthetic unity). This is similar to one being in physical contact with a material object. One can be in contact with different objects at different times. The worm theorist is committed to the idea that she is ('now'-ontologically) in contact with all the objects her different stages have been (are, and will be) in contact with. But she is not at all committed to the idea of there being a unique object that is the mereological sum of all the objects she, as a worm, is in contact with. All of those commitments (and lack thereof) are justified by her conception of continuants and her theory of time, and are quite independent of whatever is available to her through introspection at various times.

Are those other times which have those experiences a part of me right NOW? If not, then they don't count.

Under the worm theory, they should be a part of me NOW (since they exist), so so much as I am talking about my total experiences, it should, assuming the worm theory, include experiences of all these times. — Mr Bee

According to worm theory, those future and past experiences would be experiences had by stages of yourself that are part or you now in the ontological sense of "now". They are not experiences had by you now in the ordinary sense of "now" (i.e. the temporal location sense of "now"). Let us use "now-o" (ontological) and now-tl (temporal location) to disambiguate those two senses as distinguished by the eternalist theorist. Provided that you don't equivocate between those two senses, then it seems that P3 asserts that you are not experiencing anything other than sitting at your computer now-tl. But it doesn't follow from this introspectible fact that you aren't experiencing other things now-o. In fact, you are experiencing now-o everything that you experienced in the past or will experience in the future, according to the worm theorist. Of course, you can not know this on the basis of your introspective experience now-tl alone. But you can know it on the basis of your reflection on the meaning of "now-o", your memory of your own past experiences, and your expectations regarding your own future experiences.

What you call "opposite" often is called "contrary". Contrariety and contradiction are two sorts of opposition. Look up Aristotle's Square of Opposition. (Also on the SEP)

I'm into J J Gibson's 'ecological approach' at the moment. He argues that his approach is non-dualistic and even makes playful reference to ecological physics. This is on the basis that for an animal to perceive an object is for it to see the 'affordances' available from the object, i.e. the natural world is a vast network of mutual relations of affordance, an approach derived from gestalt psychology. — mcdoodle

Did you read The Ecological Approach to Visual Perception? Gibson is the most philosophical of all the psychologists. My understanding of Aristotle's metaphysics, of Kant's epistemology, and of the inseparability of practical and theoretical reason, are conditioned by Gibson's concept of an affordance.

Maybe it is, but even so, I am still not sure why you think that is. Let me repeat once more the version of P3. that I have been proposing:

P3. I find that I am only experiencing sitting in my room during the temporal duration in which I exist. (This is what I find through introspection upon my direct experience) — Mr Bee

But this seems prima facie false, assuming only that your existence extends both to the past and to the future (or even, only to the past). It only appears true under the assumption that your own existence is restricted to the duration of your present experience. But this assumption seems to build stage theory onto your premise P3. (Or, more precisely, it builds into P3 a feature of stage theory that distinguishes it from worm theory).

what is your opinion on the cosmological arrow of time in relation to inflationary theories; I lean more towards Guth' model and his model rests mostly on the physics of scalar fields. — TimeLine

This model makes much sense to me, but I am not in a position to assess it against competitors. (In fact, I don't even know what the viable competitors might be. When I was studying physics, I attended a graduate seminar in cosmology given by Hubert Reeves, but that was more than 20 years ago and I didn't consolidate that learning. So you must be much more knowledgeable than I am)

Are you talking about the star itself or the stellar region? The entropy lost by the star is certainly not at an equal sum to what it gains by its surrounding, so you would need to further elucidate this point. — TimeLine

First, apologies, when I said "when the temperature of the newborn star is lost...", I meant "heat" not "temperature". I was picturing the temperature of the star and the temperature of interstellar space evening out.

I can make my point a little more precise through breaking up the process in two stages (i.e. two merely notional stages, because they normally overlap). In the first stage, gravitational instabilities are magnified into local gravitational collapses of large clouds of gases. Under the effect of self-gravity, those clouds heat up adiabatically. Adiabatic compression is a thermodynamically reversible process and so doesn't give rise to any entropy change within the collapsing gas masses (neglecting chemical or nuclear reactions). But then, in the second stage, the nascent stars (or hot gas clouds) begin radiating heat away to the comparatively colder space between them. It is this temperature inhomogeneity that can be harnessed to produce useful work (as indeed life on Earth makes use of). The process involved in this second stage isn't reversible since, as you note, more entropy is generated by the production of low energy photons (the warming up of cold space) than is lost to the cooling down of the stars.

"Let's assume" was an example to make things easier to understand. That was not my view or built into my P3. I am willing to assume in my OP that our existence can be any duration of time, whatever it happens to be. — Mr Bee

Yes, that might have been your intent in the original post of this thread. (Your argument, back then, seemed to hinge on something like the synthetic unity of experience). But, just now, you had offered this as an explanation (for The Great Whatever) as to why you only are experiencing sitting at your computer, while excluding other experiences had at earlier or later times in your life. You also meant to insist that your intention wasn't simply to restrict reference to what you are experiencing now, but rather to what you are experiencing while you exist. This argument, which doesn't appeal to the idea of synthetic unity of experience anymore, now seems to hinge on a restriction of the temporal scope of your existence. And this is what distinguishes stage theory from worm theory.

Where did I assume that? Can you quote the phrase? — Mr Bee

"Let's say that the entire duration in which I exist is limited to an instant."

Have you even read my post? I literally just explained how in the paragraph above it. — Mr Bee

In this paragraph you enjoin us to assume that the existence of the experiencing subject is restricted to a moment in time. This is an assumption that distinguishes stage theory from worm theory. If this assumption is thus built into your premise P3, that would make your argument in favor of stage theory circular.

Yeah, the universe had better begin with a low(er) entropy, but I don't know if I would call a homogeneous gas a "perfect order". — SophistiCat

Yes, this sounds a bit paradoxical when one is used to consider examples of low and high entropy restricted to systems that aren't dominated by gravity. Gases and liquids in closed boxes, for instance, display maximum entropy in homogeneous states. Yet, for gravitational systems characterized by a universal attractive force between the components, the opposite is true.

Think about the measure of entropy as the opposite of the measure of energy-available-for-work. In a vast cloud of gas (or individual stars) that is homogeneously distributed in space, gravitational instabilities can give rise to local gravitational collapses in which things heat up. This creates spatial varations in temperature that can be used for producing work. As the temperature of the newborn stars is lost to cold space, usable energy goes down and entropy goes up. The reverse process -- the "re-homogenization" of those stars and galaxies would require external work. Usable energy would go up and entropy down. (This can also be explained through the standard statistical mechanical definition of entropy as the logarithm of the number of micro-physical configurations. Counterintuitively, it so happens that gravitational systems have more spatially inhomogeneous states available to them than homogeneous ones. This is an interesting fact to reflect about.)

I have proposed an alternative conception of "now", describing the "temporal region in which I exist" as a better description of what I would mean when I would have to use the word now. I even gave an analogy involving our use of "here" to support it. After all, "here" simply specifies my location, not that of the utterance, and it seems like "now" should similarly specify the location in time, not of the utterance, but of myself, whatever that may be. — Mr Bee

I would have thought that "here" refers to the location of the speaker at the time of utterance. (This is how, at any rate, I would make explicit what the reference of "here" is, in particular occasions of its use, without this being meant as an explanation of its Fregean sense.)

For instance, Sue could be teaching Max how to tidy up the workshop. She tells him: "Go fetch the hammer over there and bring it back here". Then, she accompanies him to the place where the hammer is. It would then be odd for Max to insist that the hammer now is located where Sue wanted it to be on the ground that "here" refers to the place Sue (now) is standing. Of course, if both Sue and Max are stage theorists (and not just armchair stage theorists, but people who strive to live up to stage theory in everyday talk) then they may want to reform the way in which they use indexicals. In that case Max's later counterpart may take himself to be committed to obey the instruction that had been given by Sue's younger counterpart to Max's younger counterpart. In light of Luke's earlier suggestion in this thread, this may be seen as a way of construing the semantics of indexicals that attempts to retain the dynamicism of ordinary presentism within a 4-dimensionalist framework. (Incidentally, Gareth Evans's neo-Fregean account of enduring thoughts that can be re-expressed at successive times without loss of meaning with the use of inter-related classes of demonstratives or indexicals (e.g., "here" and "there"; or "yesterday", "today", "tomorrow"...) characterize such thought as dynamic thoughts).

Apparently that didn't sit well with you because that is not what the word "now", as commonly construed in our everyday language, is used. Technically, under something like a layman presentist framework, the word "now" can refer to both the time in which I exist and the time of the utterance, but that is certainly not true under something the worm view (or really any view that allows for a temporally extended experience). If this type of view isn't satisfactory to you then I will probably need more of an argument to be convinced.

If ordinary language is to retain a pragmatic use (and some of its meaningfulness) as interpreted within a stage theoretical framework, then, although indexicals may be taken to make no (direct) tacit reference to the time of the utterance, they would still have to make tacit reference to the specific stage of the individual to whom later stages of this individuals (and of other people) are referring back to while interpreting the original utterance. This still seems to amount to making a tacit (albeit indirect) reference to the time of utterance. To completely give up on such tacit references to past and future times would lead to the disintegration of 'dynamic thoughts' and the narrowing down of experience (and of the acts of reference therein) to a narrow Cartesian space of private sense data, it seems to me.

I don’t fully comprehend the distinction between stage theory and worm theory, but they are both consistent with a 4-D block universe, and a 4-D block universe is consistent with a static, motionless universe. Endurantism, on the other hand, is consistent with a 3-D dynamic (presentist) universe. I believe that the perdurantist “stage theory” is an attempt to incorporate some dynamic aspect into the static 4-D block universe, but I consider these to be irreconcilable.

... — Luke

This strikes me as a very sharp diagnosis of the motivation of the stage theory.

Like I told Pierre, when I say that I find myself as only having the experience of, say, me sitting in my room, I am not saying that I am having them "at a time". Nowhere does such a notion come into my description of what I am experiencing. I only say that I am only having this experience in a general sense. — Mr Bee

But this is just to say that the time at which you are having an experience doesn't figure explicitly as part of the content of this experience. You can distinguish, though, right now, between your relating to experiences had by you in the past, in the present, or in the future. You can say, and believe: "I saw my friend earlier"; "I am seeing my friend now" and "I will see my friend later". In those forms of expression the words "earlier", "now", and "later" function as indexicals. The times that they refer to are functions of the time when the expressions are being uttered. (Likewise, the word "I" can refer to you by dint of the fact that it is being used by you; and the word "here" refers to a specific place by dint of its being uttered by someone located at that place.)

When you are enjoying the visual experience a tree, you need not be thinking of this experience under a mode of presentation (i.e. a Fregean sense) that could be expressed thus: "I am seeing this tree at 4:16 PM on April 10th 2017". You could also be expressing the same content under the different mode "I am seeing this tree now", which is equivalent to the content of "I am seeing a tree". In the latter form of expression, the temporal reference of the expression "now" is tacitly encoded into the tense of the verb "seeing" (together with the progressive aspect). It thus has the same Fregean sense. You can't really have a visual experience while being agnostic regarding the time when you are having it (i.e. regarding its being either present, past or future). If you are doubting whether an experience is a present visual experience or a fuzzy memory, for instance, then you are doubting its very status as an experience as opposed to its being a product of your imagination, say.

I, as the entity that should be a temporally extended conscious subject, only have an experience of sitting in my room in front of my computer simpliciter. This is just how it feels to me. — Mr Bee

Yes, and the worm theorist need not dispute that. But then, at a later time, you go out and see a tree in the garden. You are having another experience with a different content. The worm theorist says that those two events relate you, the very same individual (or space-time worm) to the two separate contents of those experiences. But just because the same individual is thus related to two separate experience contents doesn't contradict the fact that, as part of the form of those very experiences, you are picturing yourself as having them in isolation (in the "present time" when you are having them). All this goes on to show, from the point of view of the worm theorist, is that the different segments of the "worm" are, indeed distinctive parts of that worm with distinguishable properties.

So because your degree is bigger (or something else for that matter) than mine, you think you automatically know more than me? — dclements

I think Ernestm was merely paying you a compliment.

My objection to this theory is that it sure as hell seems like I have thoughts that change over time and not that I'm stuck in my single thought. The concept of change seems impossible under an eternalist theory because there is no becoming, just existing. — Hanover

I quite agree. But I think both the views of endurantism (closely associated with stage-theory) and perdurantism (closely associated with eternalism or 4-dimensionalism) make it hard to account for the metaphysics of change. I used to be committed to endurantism, myself, but Sebastian Rödl (see his Categories of the Temporal, HUP, 2012) made me realize that everything that the perdurantist may want to say can be translated without loss in the language of the endurantist, and vice versa. What is really missing to both from those view about time, objects and predication, is the Aristotelian concept of a substance.

On edit: contrary to what I said above, stage-theory is more commonly viewed as a variety of perdurantism. This makes sense, since endurantism entails that when a "stage" is present, then the whole objects is present, although its past "stages" don't exist anymore, and its future "stages" don't exist yet. Hence, worm theory and stage theory are two varieties of perdurantism.

It seems that this type of response collapses to the stage theory does it not? Cause if we are going to grant that there are multiple different conscious subjects who exist at every stage of our lives anyways, then why not just adopt the stage view? — Mr Bee

That's because the eternalists (or the perdurantists) aren't saying that there are different conscious subjects along your world-line. You are the whole worm, and your temporal time-slices are temporal parts of yourself just as much as your hands and feet (or rather, their own worms), say, are "spatial parts" of yourself. What the eternalist may argue is that your having experiences one at a time doesn't contradict your being a worm who is having those experiences anymore that your being touched by someone on specific parts of your body, say, contradicts that it is you, the same individual, who is being touched in each case.

As far as I know, the worm theory claims that there is one only entity, one conscious subject which identifies with the whole spacetime worm.

Agreed.

Although it is conceivable to argue that such a being could also exist on top of the multiple conscious subjects at every time it would seem unnecessary to do so.

Agreed. The defense that I mustered on behalf of the eternalist doesn't need that.

Welcome to the forum!

...So here is my argument in a nutshell against the worm view:

P1. The worm theory requires that we are temporally extended beings.
P2. If we are temporally extended beings, then we must have all of our experiences at every time in which we exist together*.
P3. Our experience is limited to only one time.
____________________________
C. The worm theory is false.

* Note that by saying that I should have all of my experiences "together", I do not mean that we have all of our experiences "at once" as in "at a time". Our experience can extend across multiple times, just as much as our bodily experiences at a single time is spatially extended (I see through my eyes and feel through the nerves in my body for example). The point is that we have them all. — Mr Bee

This note is indeed an important concession for you to make to the proponent of the worm-view, (which is a view about identity also called perdurantism). But its seems to me that it is hard to make consistent with your defense of P3. (See below)

The support for P3. is simply based upon introspection about our direct experience. My judgement I am not experiencing any other times shouldn't be illusory any more than my judgement that I am not in excruciating pain, or that I my judgement that I am having a red experience, which I take to be pretty certain. For me, I find that my experiences are only limited to me sitting here typing up this post at this time and nothing else, and I believe that a similar finding would hold for you too. This experience of me sitting in my room in front of my computer is not had as part of any other experience or together with other experiences at other times. — Mr Bee

I think the worm-theorist would readily accept the way you are characterizing the content of your experience (i.e. what it is you are experiencing) but she would question your portrayal of what it is to be the subject of a singular experience. The worm-theorist would claim that each separate content of experience had by you over time is being had (which denotes a singular event rather than an ownership relation) not by "your" perduring worm as a whole, but rather by just the one contemporaneous temporal stage of your worm that is occurring at the time when this experience is being had. Hence, the fact that you (the whole worm) are truly only experiencing one thing at a time just reflects the fact that those episodes (or events) of experiencing something or other characterize your own temporal stages separately. In yet other words, your saying that you only experience one thing at a given time only boils down to saying that only one single temporal stage of yourself (i.e. just one time-slice of yourself) is involved directly in this experiencing. (There may still be indirect involvement through the exercise of memory and anticipation).

Is it that there were more photons released from dense regions because they contained more photons? Did the gravitational strength differential of these more dense regions cause more photons to be emanate from specific trajectories at the time of decoupling? — VagabondSpectre

As far as I know, the acoustic oscillations are a result of gravitational instabilities. Once this is accepted, you don't need a further mechanism to explain why there are more photons coming from the denser regions. If there are more atoms recombining in a given volume of space, then, of course, there are going to be more photons being emitted from that volume.

It is certainly one of the more mystical aspects of Wittgensteinian thought, and does take some time to grasp. Reading the tractatus, red book, and blue book is helpful. — ernestm

Those would be the Blue and Brown Books. The Red one is from Chairman Mao ;-)

There is a fundamental difference between the sort of reasoning exemplified by these Vedic philosophers - or for that matter by ancient atomists - and later scientific models like quantum physics (or atomic physics). The former is a priori reasoning, motivated by abstract (pseudo-)puzzles. It bears no relation to the motivations behind the later scientific models, and any resemblances between the two are accidental and superficial. — SophistiCat

Many of the puzzles, as well as many of the insights, were real, it seems to me. There are both deep differences and deep similarities. If you read the intellectual biographical recollections of Heisenberg (or Schrödinger, or Einstein) you'll find that there are lots of philosophical and other a priori considerations that grounded their theoretical innovations. Of course there is a sort of interplay between theory and experiment that rests on the practice of the mathematical formalization of the laws of physics (and of the laws of some other special sciences) and the derivation of precisely quantifiable predictions (and explanations) that wasn't developed until recent centuries. This profound difference doesn't negate the profound similarities.

You asked what time could be reversed relative to. — tom

Maybe someone else, not me. I didn't touch on the issue of the arrow of time. I was only considering the intelligibility of the idea of shifting the temporal scale (or all events) four hours in the past (or in the future), in analogy with the idea of a uniform translation of space itself.

The possibility that time and space are limitless is confusing me. But is that a problem? Can the thought experiment just say that for every E, E happens 4 hours earlier? And not address whether time is finite or infinite? — Mongrel

The same question arises. Relative to what is everything happening four hours earlier? You have to imagine some undetectable framework of time (rather in the way one might want to picture empty space, metaphorically, as an empty stage) relative to which events are dated extrinsically. But if that's the case, then there would have occurred a shift in the time of occurrence of all the empirical events, all right. But time itself would not have shifted since it would have been externalized, as it were, to this inobservable framework.

Let us get back to the space analogy. We could imagine "space itself" being externalized in a manner somewhat analogous to the luminiferous aether of pre-relativistic physics; with the proviso that such an aether would be physically undetectable in principle. Can then everything in the universe be conceivably shifted 100 feet in one determinate direction? This can be conceived. But you still would not have shifted space itself, since on that account, space would have been externalized. It has been identified with the absolute spatial "positions" of the aether "stage". And this aether still would not have moved. If you were to imagine that the aether (space itself) also moved, then that must be a movement relative to some external spatial framework. You need another aether to identify "space itself" with. You are led to an infinite regress.