Is Time an Illusion?

[pallidin]

If time did not exist it would not be possible for you to respond to these posts AFTER your question.
Else you would have done such simultaneously, which did not happen.

 

[ThomasT]

I meant simpler to observe, in the sense that it requires no knowledge of physics or special tools. There are other types of events that only happen in one direction. Rocks, for instance, don't ever fall from the bottom of a cliff to the top. Rivers never flow uphill. Explosions don't contract and become bombs. Bullets don't fly backwards out of targets and into guns. Abraham Lincoln's skeleton won't crawl out of his grave and grow flesh and then de-age into an infant.

Observation of these types of events would make it justified to say you're traveling into the past.

I like to illustrate time by dropping a pebble into a calm, smooth pool of water. There's no going back in time, because there's no back in time to go back to. The expansion of the disturbance in the pool of water is characteristic of all waves on all scales. Why would the 'universal wavefront' be expected to be any different? If our universe is an evolving disturbance in some unknown medium, then backward time travel is impossible.

 

[ThomasT]

If time did not exist it would not be possible for you to respond to these posts AFTER your question.
Else you would have done such simultaneously, which did not happen.

A timely reply.

 

[Descartz2000]

It depends on what you mean. It's not as if the whole universe stepped through increments of time together, in sync. So what do you mean by past? The local past of a stationary chunk of space? GR tells us that time is not absolute, so the idea of "past", as we intuitively view it, is misleading.

Of course, I wouldn't say it doesn't exist; just that it doesn't exist as we know it.

I agree. It seems the past is only the 'past' (12 pm) because I am viewing it from my present now state (1 pm). It seems that 1pm carries no more value in how 'real' it is, than that of 12pm. There is no past that exists, it is only a previous present state of 'now'. If the past is the past as we intuitively think of it, then what is that past state when I am experiencing it? This points to the conclusion that the past is only an illusion.

 

[Descartz2000]

I agree it's important to point out that past and future have meaning from some particular standpoint in the world -- not globally. From any physical point of view, though, there is a "past" that was "real" once but isn't any more, and there (presumably) will be a future that isn't "real" yet.

It seems intuitive to expand the notion of reality to include everything that ever actually happened up till now, and maybe everything that ever will happen too. But that doesn't seem to describe the physical world very well, once we get beyond classical physics into quantum theory and /or relativity.

The basic problem with our intuition, I think, is that we want to "step outside" our own point of view and imagine the universe "objectively" -- as if all of space and time could be "seen" in some sense at once, without actually being IN it somewhere. As if we could put the universe and its history on our desks and look at it from all angles. But I think the lesson of recent physics is that "you have to be there." If you abstract from having a particular point of view IN space and time, you can no longer conceptualize the world consistently.

I agree with much of what you wrote, but I think the point is that just because we single out a point in time and then claim the past is the past and the future is out there waiting from this unique view point is incorrect. It seems this appears true from this view point in time, but objectively it is not. So, in other words, there is an objective view point in principle, in the sense that claiming no single viewpoint in time has any more value than any other. So, in this regard, the past and future are really just illusions of my experience. No 'now' state stands out more than any other simply because I claim my 'now' state here as I write this is more valid than the moment I had 5 minutes ago. The value does not change between these states, it is only my view point that changes.

 

[Pythagorean]

I agree. It seems the past is only the 'past' (12 pm) because I am viewing it from my present now state (1 pm). It seems that 1pm carries no more value in how 'real' it is, than that of 12pm. There is no past that exists, it is only a previous present state of 'now'. If the past is the past as we intuitively think of it, then what is that past state when I am experiencing it? This points to the conclusion that the past is only an illusion.

I wouldn't say the past is only an illusion. The current state of the universe is still dependent on the past state in my mind, so what does exist is the history. The past exists in the sense that history exists, but because there's no simultaneity, constructing that history on an absolute scale seems paradoxical to me.

 

[apeiron]

So, in this regard, the past and future are really just illusions of my experience. No 'now' state stands out more than any other simply because I claim my 'now' state here as I write this is more valid than the moment I had 5 minutes ago. The value does not change between these states, it is only my view point that changes.

If you view the situation thermodynamically - where time does have an objective direction, there is some entropic gradient to be run down - then there is an objective measure of even psychological state.

For the ordinary material world, things unwind. Entropy increases with time, and so objectively distinguishes past states from now states, and future states.

For complex dissipative structures that arise on entropy gradients, like life and mind, there is instead an opposite process of increasing negentropy - information accumulated in the form of constraints.

This is what memory is. Habits and knowledge that accumulates over time and increasingly constrains our ability to respond to the world. For a child, everything is fresh and new. For the aged, everything is increasingly familiar and stereotyped, a well rehearsed response.

So we can all say that towards our psychological past we were immature (in the entropic sense of being less constrained, less developed). And towards our future, we will become senescent (overloaded with constraints, reduced in our capacity for novel responses). Right now hopefully we are in the mature system phase where habit and creativity are in fruitful balance.

Of course, this is change over a lifetime, not 5 minutes. But we can still say that a different sets of constraints (expectations, goals, anticipations, etc) were ruling us 5 minutes ago. And so that moment can be distinguished from this moment in terms of its particular informational constraints.

You also have to factor in the process of generalisation - memories gradually become less particular, more general, on the whole. That is how habits and routines form. And how detail gets forgotten.

So psychologically - for humans, who have the words to shape the habit of "remembering" prior mental states: ie anticipating or forward modelling what it would be like to be "me back then" - we can compare our now (as a particular state of mental constraint) with memories of other recent different nows (with some different particular collection of ideas and goals).

The illusion lies in thinking we are actually going backwards in time in any way. The ability to recall the past is in fact a feat of forward projection just like any other form of mental imagery. Brains are designed for anticipation (which is why animals have only recognition not autobiographical recall). And humans have just learned the trick of imagining "backwards" to prior states along a thermal gradient.

So objectively, only a forward orientation in time exists - from being to becoming, from the actual to the potential. But the past increasingly constrains our potential reponses as informational constraints accumulate and our ability to entropify becomes itself limited (the biological definition of senescence, or fragility to environmental perturbation).

 

[Galteeth]

Agreed - but not necessarily that it is a simpler indicator.

I was making the familar argument that entropification is the global arrow of time. It points out the ultimate and irreversible direction of all change.

But as well as a direction, there is the question of rate. Time moves forward (entropy procedes) at some actual speed. For the universe it follows an asymptotic curve set by an expanding/cooling field of radiation - the CMB.

Now life and other kinds of dissipative structure are in fact examples of order or negentropy - an action against this general gradient. But then of course, living systems pay for their back-pedalling against the general flow by at the same time accelerating the local rate of entropification in their immediate environments. They create more waste heat faster than would otherwise exist by simpler processes, such as the redshifting of the CMB.

So you have the CMB cooling at it steady rate. Then you have more complex systems that accelerate that rate - and so pay for their own "deceleration", their own persistent order or lack of change as structured systems doing things like growing and metabolising.

So life exists by slowing time, the natural rate of entropification, you could say. But only by balancing the books by also accelerating it to the same degree. Overall, it balances out in the long run for the universe, confirming its global arrow and global rate.

I would certainly call that a complex indicator (though a simple one perhaps if we are just talking about direction, rather than direction and rate).

Life does not exist by slowing time per ce, in the sense you're using it, it speeds it up. The thing about global entropy is that while order decreases globally, information is expanding and the complexity of information (or negentropic enclaves if you like) is increasing. By thinking of thermodynamics as an extension of information theory this makes a bit more sense. It's like a book. The more of the story you've read, the less of the story their is. Or--- A book with a lot of blank pages might be highly ordered, but not very interesting. But it has infinite potential. The more you write, the more constrained the possibilities become... but you have to "pick" a story to write if there is going to be anything interesting overall.

The slight problem with this metaphor of course is that no one is "writing" the evolution of the universe... it's just my hunch but I think the tendency towards "high negentropic enclaves" or life is going to turn out to be stronger then people currently think.

 

[Descartz2000]

I wouldn't say the past is only an illusion. The current state of the universe is still dependent on the past state in my mind, so what does exist is the history. The past exists in the sense that history exists, but because there's no simultaneity, constructing that history on an absolute scale seems paradoxical to me.

But, the crux is not if the two events are simulataneous. They do not exist at the same physical times and locations, but they both exist equally at differing times and locations where one has no objective value or 'realness' over another in principle. If this is true and the 1pm event is as real and existing as much as the 2pm event, then how can I claim that both are not real and true in an objective sense at all times. So, in other words, if no specific time is identified or singled out as my place to view from, as both are equally as valid, then I can't claim at any point that one is true and the other is not. It may appear true from that viewpoint, but why is that viewpoint more or less valid than the other?

The past is an illusion in the sense that there is no true past. There is a 'past' from my current viewpoint, but what is the 'past' from this viewpoint, is the 'future' from another, and since neither is more valid, then the 'past' is just a perspective and it is an illusion. I'm not sure that 'history' plays such a big role here. It seems the 'equally real' events at 1pm and 2pm are key when talking about simultaneously valid states.

 

[Descartz2000]

If you view the situation thermodynamically - where time does have an objective direction, there is some entropic gradient to be run down - then there is an objective measure of even psychological state.

For the ordinary material world, things unwind. Entropy increases with time, and so objectively distinguishes past states from now states, and future states.

For complex dissipative structures that arise on entropy gradients, like life and mind, there is instead an opposite process of increasing negentropy - information accumulated in the form of constraints.

This is what memory is. Habits and knowledge that accumulates over time and increasingly constrains our ability to respond to the world. For a child, everything is fresh and new. For the aged, everything is increasingly familiar and stereotyped, a well rehearsed response.

So we can all say that towards our psychological past we were immature (in the entropic sense of being less constrained, less developed). And towards our future, we will become senescent (overloaded with constraints, reduced in our capacity for novel responses). Right now hopefully we are in the mature system phase where habit and creativity are in fruitful balance.

Of course, this is change over a lifetime, not 5 minutes. But we can still say that a different sets of constraints (expectations, goals, anticipations, etc) were ruling us 5 minutes ago. And so that moment can be distinguished from this moment in terms of its particular informational constraints.

You also have to factor in the process of generalisation - memories gradually become less particular, more general, on the whole. That is how habits and routines form. And how detail gets forgotten.

So psychologically - for humans, who have the words to shape the habit of "remembering" prior mental states: ie anticipating or forward modelling what it would be like to be "me back then" - we can compare our now (as a particular state of mental constraint) with memories of other recent different nows (with some different particular collection of ideas and goals).

The illusion lies in thinking we are actually going backwards in time in any way. The ability to recall the past is in fact a feat of forward projection just like any other form of mental imagery. Brains are designed for anticipation (which is why animals have only recognition not autobiographical recall). And humans have just learned the trick of imagining "backwards" to prior states along a thermal gradient.

So objectively, only a forward orientation in time exists - from being to becoming, from the actual to the potential. But the past increasingly constrains our potential reponses as informational constraints accumulate and our ability to entropify becomes itself limited (the biological definition of senescence, or fragility to environmental perturbation).

I'm not sure that because things unfold in linear manner that there is a true and objective distinction between past, present, future states. It seems that to claim past and future states are objectively true is misleading. It seems there is a direction of how things unfold, but you can't pick one state and declare that it is more valid than another. But, if true, then how can you ever claim there is a past, as I must claim a present 'now' state as more valid to view this from. If I can't do this, and I accept that all states are present 'now' states, then what we think of as past, present, and future states have no distinction. They may have an order of unfolding, but they do not have a value difference in terms of being real or valid. So, all states are equally valid and true in principle regardless of my viewpoint.

 

[Galteeth]

I'm not sure that because things unfold in linear manner that there is a true and objective distinction between past, present, future states. It seems that to claim past and future states are objectively true is misleading. It seems there is a direction of how things unfold, but you can't pick one state and declare that it is more valid than another. But, if true, then how can you ever claim there is a past, as I must claim a present 'now' state as more valid to view this from. If I can't do this, and I accept that all states are present 'now' states, then what we think of as past, present, and future states have no distinction. They may have an order of unfolding, but they do not have a value difference in terms of being real or valid. So, all states are equally valid and true in principle regardless of my viewpoint.

Well, only one "state", that is, the constantly moving into the future "present" exists in the absolute sense. The past and future projections are usefully constructed models, but whether they have any existence independent of the human mind (which exists in that funny moving present state) is suspect.

 

[apeiron]

I'm not sure that because things unfold in linear manner that there is a true and objective distinction between past, present, future states. It seems that to claim past and future states are objectively true is misleading. It seems there is a direction of how things unfold, but you can't pick one state and declare that it is more valid than another. But, if true, then how can you ever claim there is a past, as I must claim a present 'now' state as more valid to view this from. If I can't do this, and I accept that all states are present 'now' states, then what we think of as past, present, and future states have no distinction. They may have an order of unfolding, but they do not have a value difference in terms of being real or valid. So, all states are equally valid and true in principle regardless of my viewpoint.

If you believe that the state of things has to be crisp and definite - something either is or it isn't - then you indeed face a logical bind. Past and future are either states that are - which ends up in the deterministic block time view where the now is an illusion - or instead only the now is real, which makes past and future the illusion.

So yes, think that way and you are trapped into mutually contradicting positions, neither of which feels right.

Which is why I stressed the further dimension to reality, the dimension of development that runs from the vague to the crisp, from becoming to being, possibility to actuality, etc. This is a traditonal idea in metaphysics even if it has become largely lost in physics.

So the past is definite (it cannot be changed) while the future is indefinite (it is still full of vague potential, a capacity for change, while also of course highly constrained because of a weight of accumulated history).

The best kind of model of this could be a scalefree network or other "edge of chaos" model where the "now" is a mix of past and future - a powerlaw mixture of the changed and the changing, islands of stasis and flux.

Look inside the "now" of the universe - which can be measured in a general way by its current temperature - and you will be able to see that it is in fact an average of local "nows".

This follows from the transactional interpretation of QM, a la Cramer, I believe.

 

[Max™]

Is this moment, as I am typing this, now?

If so, why does this moment a short time later feel like now?

Is there a wall of change sweeping across the universe, busily sorting things into past states, which my awareness happens to be surfing happily along with?


If so, can I not determine an absolute definition of simultaneous events, and thus destroy the very foundations of relativity?

If relativity is to hold, then I am forced to consider the possibility that my "now" is not unique, and that it is most likely an artifact induced by the manner in which my brain stores information.

The connection between my sense of self, that feeling that I am existing, and the temporal data encoded in my mind, is perhaps the source of all this confusion?


Perhaps I am little more than a bookmark, a misplaced one at that, constantly stating that I am here, while I am actually registering my self being at a different point on the page entirely!

 

[Descartz2000]

If you believe that the state of things has to be crisp and definite - something either is or it isn't - then you indeed face a logical bind. Past and future are either states that are - which ends up in the deterministic block time view where the now is an illusion - or instead only the now is real, which makes past and future the illusion.

So yes, think that way and you are trapped into mutually contradicting positions, neither of which feels right.

Which is why I stressed the further dimension to reality, the dimension of development that runs from the vague to the crisp, from becoming to being, possibility to actuality, etc. This is a traditonal idea in metaphysics even if it has become largely lost in physics.

So the past is definite (it cannot be changed) while the future is indefinite (it is still full of vague potential, a capacity for change, while also of course highly constrained because of a weight of accumulated history).

The best kind of model of this could be a scalefree network or other "edge of chaos" model where the "now" is a mix of past and future - a powerlaw mixture of the changed and the changing, islands of stasis and flux.

Look inside the "now" of the universe - which can be measured in a general way by its current temperature - and you will be able to see that it is in fact an average of local "nows".

This follows from the transactional interpretation of QM, a la Cramer, I believe.

But, it seems the 'now' is all that is real. I am not agreeing with presentism. However, how can I not claim that every state has its own state of 'now'. If true, and all states are now states at their own unique times, then in principle, when they physically are present, they are real and existing. However, since no now state is more or less preferred to view from, then I can't claim that anyone of these now states is not existing in principle regardless of my viewpoint? And I do claim the past and future are illusions simply because they are not objectively true. A future state is not an inherent future from all viewpoints. Some viewpoints might claim it to be a present and past state.

 

[Descartz2000]

Is this moment, as I am typing this, now?

If so, why does this moment a short time later feel like now?

Is there a wall of change sweeping across the universe, busily sorting things into past states, which my awareness happens to be surfing happily along with?


If so, can I not determine an absolute definition of simultaneous events, and thus destroy the very foundations of relativity?

If relativity is to hold, then I am forced to consider the possibility that my "now" is not unique, and that it is most likely an artifact induced by the manner in which my brain stores information.

The connection between my sense of self, that feeling that I am existing, and the temporal data encoded in my mind, is perhaps the source of all this confusion?


Perhaps I am little more than a bookmark, a misplaced one at that, constantly stating that I am here, while I am actually registering my self being at a different point on the page entirely!

I think it depends on when/where you ask the question. If I ask: "is this moment more real here at 12pm than all other times?". I may respond "yes, it is, because I am asking the question now". But, what if I ask the exact same question tomorrow, and the next day, and the day after that? Is there a 12pm that stands out as more real than the others? If not, then how can I claim in an objective sense that anyone of them is more real or valid than any other? I can't. Therefore, every now state is equally real and true. Maybe, all are not physically true at the same times (as the process of changing states is linear), but all are true now states, and in principle they all exist simultaneously.

 

[ConradDJ]

Is there a wall of change sweeping across the universe, busily sorting things into past states, which my awareness happens to be surfing happily along with?

...If relativity is to hold, then I am forced to consider the possibility that my "now" is not unique, and that it is most likely an artifact induced by the manner in which my brain stores information.

The connection between my sense of self, that feeling that I am existing, and the temporal data encoded in my mind, is perhaps the source of all this confusion?

There is pretty strong evidence that there is no "wall of change sweeping across" the whole universe at once. I think what relativity tells us is that the present moment "now" is local to every point of view. My "now" as I write this is connected to your "now" as you read it, by electronic signals and data-storage units. But they're not the same now. Unless we're face-to-face with each other in more or less the same place, we don't really share the same "now".

I don't see that this makes the "now" any less "real" or "unique" or significant for each one of us. And as to the confusion -- I think we need to distinguish the temporal structure we build in our minds and put on our calendars, and measure with clocks -- the objective "time-line" used in history and physics -- from the "being here" aspect of time, the experience of time "from inside". The latter isn't necessarily something "in our heads" or a figment of consciousness. The "now" I'm living in presumably includes all these things around me -- it's no less "physically real" than the time-line, but it's local to this "here and now."

The two aspects of time are connected in a way that maybe hasn't been well understood, in physics or in philosophy or psychology... but the thing is, they have very different kinds of structure. Objectively the "now" is at best something fleeting and undeterminable -- as soon as you point to one point on the time-line as "now", it's already past. The "now" has no meaning in Newtonian physics. But from a point of view in time, "now" is fundamental. And it doesn't instantly "go away" -- it stays here and changes, all the time. "Now" is the most basic and constant aspect of all our experience.

I think the "confusion" about Time comes mainly from a mistaken assumption that the word must refer to something simple, that we should be able to conceptualize Time as a single "process" or "dimension". But just because time is the most familiar thing in the world, to us, doesn't mean it's uncomplicated.

 

[pallidin]

Such pondering can lead to insanity.
This is why I prefer to pre-treat my fragile mind with copious amounts of sedation, normally beer.

 

[apeiron]

A future state is not an inherent future from all viewpoints. Some viewpoints might claim it to be a present and past state.

There is pretty strong evidence that there is no "wall of change sweeping across" the whole universe at once. I think what relativity tells us is that the present moment "now" is local to every point of view.

Agreed, the basics facts of relativity have to be factored into anything being said here. One observer can judge two events to be simulataneous, which to another observer follow one after the other, etc.

But this is why I like a thermal approach to time - it recognises, as Conrad says, that it is not a simple dimension, but complex. A simple view of time is that it is another geometric dimension - measured in terms of distance covered. But a complex view recognises that time can be ticked off in two kinds of units - thermalisation (cooling, entropification) as well as distance (expansion, motion). There is a duality here as these two physical processes are two sides of the same coin.

So getting back to my argument that the temperature of the universe does act like a universal clock, a global wall of change sweeping through, imagine looking up into the night sky and making a visual reading of its prevailing temperature. Registering photons.

Light cone logic applies of course. So that is a strict locality constraint. But so too does a transactional interpretation of QM, which admits thus an essential nonlocality. Individual events have a "timelessness", or rather, they turn indeterminate spatiotemporal potential into some actual crisply decohered event.

Anyway, looking up at the stars, we are catching energetic photons from all directions. But there is clearly a powerlaw relationship. In general, the stars are all equally bright, but distance makes them dim. And also further away in time, in our "past".

But from a transactional QM point of view, nothing has "happened" until the star has "decided" to emit a photon and my eye has "decided" to accept it. The connection is formed across time in some fundamental (nonlocal) sense. Once it has "happened" of course, it is a fixed part of the universe's history. It is woven into the history of the universe.

Note also that such events are always (excepting a non-zero but vanishing degree QM uncertainty) entropic - they go in the direction of a thermal gradient. My eye may emit photons of its own, but they will be way down in the weak infrared, never climbing back up the gradient to be hot like a star's emissions.

So looking up at the night sky, I am seeing photons over every distance (and hence distance back in time). But every individual event is also timeless in that it required me, as the decohering, wavefunction collapsing, observer to anchor one end of a transaction that is in fact "making time". Creating an act of communication, ie: thermalisation.

Of course, the conventional view is that the star emitted a particle, a photon, and it crossed vast regions of space, red-shifting as it went, before smacking into my retina. This is a realist view based on strict locality. It is a convenient way of modelling the situation perhaps, but contradicted at a fundamental level by QM, and the reason why some more subtle and complex model of time is actually needed.

Anyway, that is the situation. I look out at the stars and make thermalising connections with hot radiation sources over an incredible range of spatiotemporal "distances". The majority are in fact "near to" - the closer stars in the same galaxy. But in powerlaw fashion, photons could reach me from any distance within the visible universe.

So this admits that the "now" here is my now. But it is a complex now because my now is directly (nonlocally) part of some time-distant star's "now". The whole path of that photon exchange was a collapse of a wavefunction that put the star, my eye, and everything along the way, in a strict temporal order (and strict thermalisation order, as part of what happened was the red-shifting as well).

But there is also a global wall of change in this story as well. When I look out at the night sky, in every direction, over every distance and hence timescale, the sky looks pretty black. Stars (located thermal bodies) are the exception. And 98% of what I see is the global coldness, the weak thermal sizzle of the cosmic background radiation. This is a pure measure of the universes thermalisation, or cooling due to expansion and consequent red-shifting.

So mostly, my interactions are ruled by a global clock - the CMB. Just as to one side of me, there is an important heat source, the sun, to the other, there is a vast heat sink. And this is the entropy gradient that even makes it possible for us to exist as located, complex, observers.

What does this all say about the issue of "now"? Well, first up, GR alone is only a partial model. QM and thermodynamics are needed for a more complete story. As well as distance (GR), there is entropy (thermodynamics). And as well as locality (GR), there is nonlocality (QM).

Second, most of our temporal relations are either warm and short-range (the sun is only minutes away), or cold and distant. So our "now" is quite tightly defined in fact by a fairly precise position on an entropic gradient (hot foreground, cold backdrop). We can of course have thermal interactions over incredible distances (and hence times measured in distance). But these become vanishingly weak and do very little to nudge our otherwise quite tightly determined location on a thermal scale (the one locating us at some point between our dominant heat source and our dominant heat sink).

Third, it seems that thermo considerations are in fact a better way of thinking about time as a dimension. Time can be equated with distance (as distance is thermalising in practice - expansion causing red-shifting even without anything else happening). But if we equate time with change, and change with gradients, and gradients with entropification, then "now" can be seen in thermal terms. It becomes a measure of potential action.

My past is the past because that is a gradient already run down (and star light is not in my past until it has become an event registered as part of my now - and that star's now too). My now is where I happen to be on the gradient (the one between my dominant heat source and dominant heat sink). And my future is all the distance yet to slither down that entropy gradient towards the ultimate blah of a universal heat death.

 

[Max™]

Your now is just the point where your awareness seems to be directed at any given position along your worldline.

I can point to a moment as a "now" without it being in the past, case in point: the moment when you read these words is in the future from my perspective, I am pointing to that moment from the past, which I would claim was briefly a "now" from my point of view.

That "now" was a different event for me than it was for you, I was perhaps in bed, or outside whacking sticks with my bokken, using a general plane of rough simultaneity, mind.

Tomorrow, when I check back on this thread, this moment when I read these words I wrote a day before will seem like "now" to me, but I am aware as I write them that it is off that way *motions vaguely in the downstream direction of time*, or more accurately, I am aware that it can only be off in that direction, towards what I would label the future.

It is possible that I might be killed before I get a chance to fulfill that little bit of prophetic self-interaction, or the computer could crash, these boards could lose the post, or any number of different things could prevent my reading this post tomorrow.

Which raises another interesting question, why can we only recall what we did in the past?

I can not directly observe the moments when I posted in this thread yesterday, though I do hold information about them, and can even relive them to some extent by reading the post again.

I know that tomorrow from my perspective must be further downstream in time from the point I am viewing, yet I do not have information about that event, and can only relive it in my imagination.


Something interesting to think about, when I get around to thinking about it, that is.

 

[Math Is Hard]

Your now is just the point where your awareness seems to be directed at any given position along your worldline.

I can point to a moment as a "now" without it being in the past, case in point: the moment when you read these words is in the future from my perspective, I am pointing to that moment from the past, which I would claim was briefly a "now" from my point of view.

Actually, you never perceive "now". No one does. It takes a bit of time for all the information from "now" to flow through your sensory systems and be processed by your brain to have the "now" experience, and by then, it's gone. So there's always a bit of lag.

That "now" was a different event for me than it was for you, I was perhaps in bed, or outside whacking sticks with my bokken, using a general plane of rough simultaneity, mind.

Is there anything meaningful in saying one person's experience at moment x was different than another person's experience at moment x?

Tomorrow, when I check back on this thread, this moment when I read these words I wrote a day before will seem like "now" to me, but I am aware as I write them that it is off that way *motions vaguely in the downstream direction of time*, or more accurately, I am aware that it can only be off in that direction, towards what I would label the future.

It is possible that I might be killed before I get a chance to fulfill that little bit of prophetic self-interaction, or the computer could crash, these boards could lose the post, or any number of different things could prevent my reading this post tomorrow.

Why would reading things you wrote in the past seem like "now"? That might be something unique to your perspective.

Which raises another interesting question, why can we only recall what we did in the past?

Why don't purple monkeys fly out of my butt? Who knows. It's just the way things work. Your brain can't make a memory out of events your sensory apparatus hasn't come into contact with yet.

I can not directly observe the moments when I posted in this thread yesterday, though I do hold information about them, and can even relive them to some extent by reading the post again.

I know that tomorrow from my perspective must be further downstream in time from the point I am viewing, yet I do not have information about that event, and can only relive it in my imagination.

Something interesting to think about, when I get around to thinking about it, that is.

OK, but I still don't see where you aren't just restating the obvious.

 

[inflector]

...[snip]...
And QM also seems to give your argument an even bigger problem as non-locality is precisely about spanning the flow of time. You can't imagine a jumble of topologically disconnected spatial frames and still have non-locality find a way through the maze to connect them. And if you can, then the paths aren't topologically broken in the first place because the connecting paths exist.

Sort of like the many worlds argument. How can that be rendered than other as a topologically branching tree?

I know the above excerpt is from a few months back, however, as I have just for the first time read this quote, I wanted to make sure I understand it correctly.

First, you say:

You can't imagine a jumble of topologically disconnected spatial frames and still have non-locality find a way through the maze to connect them. And if you can, then the paths aren't topologically broken in the first place because the connecting paths exist.

What precisely do you mean by topologically disconnected spatial frames? Do you mean that there is no causal connection between the frames?

Could it not be the case where spacetime is very much like a tree where the connections that are causally constrained at the speed limit of C would be those defined as traversing up, down, and across the branches of the tree itself. But as with an actual tree, branches from one major bough often brush up against branches from another bough thereby bypassing the normal connection/causality speed limit? Is it not possible that non-local interactions are caused by these sorts of temporary connections between otherwise topologically disconnected spatial frames?

 

[Max™]

Actually, you never perceive "now". No one does. It takes a bit of time for all the information from "now" to flow through your sensory systems and be processed by your brain to have the "now" experience, and by then, it's gone. So there's always a bit of lag.

Well, I do perceive "now", I'm merely aware that I do a few fractions of a second after the moment which I labeled as the present.

Is there anything meaningful in saying one person's experience at moment x was different than another person's experience at moment x?

If I am attempting to define a general plane of simultaneity for Earth bound observers, I suppose there is?

We're close enough spatially, and in similar enough states of motion that the discontinuity between what I claim is a set of simultaneous events will differ little from the set you claim, only at the most distant fringes of our observable portions of the universe would we be likely to notice such small variations.

The moment when you read this, is roughly the same instant as a bird landing on a branch outside your window, as a car accident in Calcutta, as me scratching my ear upstairs.

Tomorrow, when I check back on this thread, this moment when I read these words I wrote a day before will seem like "now" to me, but I am aware as I write them that it is off that way *motions vaguely in the downstream direction of time*, or more accurately, I am aware that it can only be off in that direction, towards what I would label the future.

It is possible that I might be killed before I get a chance to fulfill that little bit of prophetic self-interaction, or the computer could crash, these boards could lose the post, or any number of different things could prevent my reading this post tomorrow.

Why would reading things you wrote in the past seem like "now"? That might be something unique to your perspective.

When I re-read the bit I quoted inside your quote here, it felt like "now", does that explain what I was saying better?

Which raises another interesting question, why can we only recall what we did in the past?

Why don't purple monkeys fly out of my butt? Who knows. It's just the way things work. Your brain can't make a memory out of events your sensory apparatus hasn't come into contact with yet.

I can't technically observe the past from my perspective either, I'm just aware that it exists due to information which I identify as having been stored in my brain at a prior date.

I am aware that the future exists as well, though I can not observe it from my perspective either.

It isn't as simple as "it's just how things work", maybe that works for you, I've never liked "just because" type answers myself.

I can not directly observe the moments when I posted in this thread yesterday, though I do hold information about them, and can even relive them to some extent by reading the post again.

I know that tomorrow from my perspective must be further downstream in time from the point I am viewing, yet I do not have information about that event, and can only relive it in my imagination.

Something interesting to think about, when I get around to thinking about it, that is.

OK, but I still don't see where you aren't just restating the obvious.

Perhaps I didn't make my point as obvious as you thought?

There is no requirement for the three spatial dimensions we observe to have a particular axis of interaction. If I move to the right, that does not require that I was moving from the left at some prior point. If I move further to the right, it does not mean I have to continue going that way. If I wish to stop moving to the right at a given speed, I can do so.

Yet, I am aware of what I find best described as motion through time, but I am unable to stop, or change direction... and even then, describing time as just a different type of spatial direction makes me want to ask silly questions.

What is the speed of left, for example?

 

[apeiron]

What precisely do you mean by topologically disconnected spatial frames? Do you mean that there is no causal connection between the frames?

I was arguing that if they were disconnected, then it seems by definition there could be no causal linkage. Otherwise - even just with nonlocal effects - there is a link of some kind.

Could it not be the case where spacetime is very much like a tree where the connections that are causally constrained at the speed limit of C would be those defined as traversing up, down, and across the branches of the tree itself. But as with an actual tree, branches from one major bough often brush up against branches from another bough thereby bypassing the normal connection/causality speed limit? Is it not possible that non-local interactions are caused by these sorts of temporary connections between otherwise topologically disconnected spatial frames?

If two branching histories touch, then by this analogy where they touched they would share the same light cone surely?

 

[inflector]

If two branching histories touch, then by this analogy where they touched they would share the same light cone surely?

Well, I was thinking that they wouldn't share the same light cone. That's why I thought this could be a mechanism for non-local interaction which seems to be present in quantum entanglement, for example.

To me, nonlocal implies non-overlapping light cones, but perhaps I have this wrong.

I've been thinking about weird topologies for spacetime that would make nonlocal correlations possible using a realist perspective. A topology/geometry that would allow a dBB interpretation of quantum mechanics to meld with general relativity. A lost cause perhaps, I know, but hey, I've always liked working on the impossible.

 

[apeiron]

To me, nonlocal implies non-overlapping light cones, but perhaps I have this wrong.

I might misunderstand you, but my view is that a non-local entanglement, as thought of in EPR, would look like two events on opposite sides of the same light cone, or branch-lets of the same bough in your analogy.

So the paradox is not that there is entanglement (because there is a shared event in the past of the two later events - the moment that created their entanglement) but that then there can be some non-local constraint that acts "instantly" to span the full width of the lightcone. So observe a particle's spin on one side, and it determines also the spin on the other side of the light cone.

In your analogy, if one bough touches another (the equivalent of an observer measuring the spin of one particle) then branchlets over the far side of the bough also shiver with that touch.

And indeed, this would be an accurate portrayal I would think. Decoherence would travel in timeless fashion to constrain everything within the light cone. The tree branch analogy might even have the advantage of giving the image of the path by which things "travel all the way back to the fork and back up the other side" rather than the alternative view of a constraint acting "instantly" across the current breadth of the light cone.

I've been thinking about weird topologies for spacetime that would make nonlocal correlations possible using a realist perspective. A topology/geometry that would allow a dBB interpretation of quantum mechanics to meld with general relativity. A lost cause perhaps, I know, but hey, I've always liked working on the impossible.

The idea of fractal branching seems to me a very natural one as it gives you an actual mathematical representation of dissipative structures - it is how entropy spreads out to fill a space of the possible. So as a "weird topology" it is in fact well motivated and quite realistic.

But again, when it comes to QM, I would see the collapse of a wave function in sum over histories terms. So before collapse, the lightcone of an event was in an indeterminate state in which "anything" was possible. After the collapse, you have some actual determined path (a branch representing a thermalising event) plus all the "air" around the branch, which is now the equally definite places within the lightcone where the event did not happen.

So nonlocality can either be seen as a constraint that "jumped instantly" across the lightcone, or instead - using the branching analogy - that the nonlocality is written into the branching structure itself. The entirety of the branch was decohered - all the way back in time to its origin - at the "moment" of observation (the brush of one branch against another).

 

[petm1]

I can't technically observe the past from my perspective either, I'm just aware that it exists due to information which I identify as having been stored in my brain at a prior date.

I am aware that the future exists as well, though I can not observe it from my perspective either.

All I see is the past, formed within my eye as an image. This image is what I think of as the leading edge of my "now", a one second frame that I will only lose upon my death. What is "real" funny to me, is that what I think of as the future are the same signals that make up this image from the past I see as the present. :tongue2:

 

[ThomasT]

So nonlocality can either be seen as a constraint that "jumped instantly" across the lightcone, or instead - using the branching analogy - that the nonlocality is written into the branching structure itself. The entirety of the branch was decohered - all the way back in time to its origin - at the "moment" of observation (the brush of one branch against another).

Your discussion of branching topologies is over my head, but wrt the applicability of nonlocality to the OP's question my first thought is that since there really isn't what I would call a significant difference between local realist models of entanglement and the quantitative results, I think it's a bit early to start speculating from the assumption that reality is nonlocal.

To answer the question in the title of the thread we just need to objectively define the terms reality and time. Such definitions do exist, and from them it follows that it's correct to say that time is real.

Of course, given the inferential speculative possibilities of modern physics, there's much more that can be said wrt the OP's considerations. And, as usual, after reading what several posters have had to say on this, I'm thoroughly confused again.

 

[petm1]

can I not determine an absolute definition of simultaneous events, and thus destroy the very foundations of relativity?

The very foundation of relativity lies in the the little twist called big bang, this one event and when it flew apart, it was simultaneous motion that was lost in space. :rofl:

 

[Max™]

The very foundation of relativity lies in the the little twist called big bang, this one event and when it flew apart, it was simultaneous motion that was lost in space. :rofl:

Twas a rhetorical question, I'm pretty well informed regarding relativity.

 

[petm1]

Twas a rhetorical question, I'm pretty well informed regarding relativity.

Sorry, did not mean to offend with my light joke.

 

[inflector]

I might misunderstand you, but my view is that a non-local entanglement, as thought of in EPR, would look like two events on opposite sides of the same light cone, or branch-lets of the same bough in your analogy.

That makes sense. I was viewing the light cones of the two measurements as two separate light cones.

Clearly, the light cone of the entangling photon generating event contains the two photons as they are measured.

In your analogy, if one bough touches another (the equivalent of an observer measuring the spin of one particle) then branchlets over the far side of the bough also shiver with that touch.

And indeed, this would be an accurate portrayal I would think. Decoherence would travel in timeless fashion to constrain everything within the light cone. The tree branch analogy might even have the advantage of giving the image of the path by which things "travel all the way back to the fork and back up the other side" rather than the alternative view of a constraint acting "instantly" across the current breadth of the light cone.

I'm just thinking of possibilities for the observed nonlocal behavior. So the tree analogy gives two separate potential approaches, touching branches and decoherence traveling up and down the branches in some superluminal fashion.

So nonlocality can either be seen as a constraint that "jumped instantly" across the lightcone, or instead - using the branching analogy - that the nonlocality is written into the branching structure itself. The entirety of the branch was decohered - all the way back in time to its origin - at the "moment" of observation (the brush of one branch against another).

Either one of these options is one that merits further thought. The possibility (however slight) that there could be some realistic explanation is what keeps me working on these sorts of ideas.

 

[Descartz2000]

I have seen several responses here that claim the present is all that is real and true. I agree with this, but every state is a present state. So, more accurately I can't claim that this particular 'now' state is only real and true. When any state is in a physical form and in a specific set of configurations, it is physically present and real. But, this logic applies to all states. So, when I claim, "my present moment 'now' as I write this is most real", I am in error because the same logic applies to all observed states. So, the viewpoint of 'now' carries no extra value than the viewpoint of yesterday's 'now' observation. So, inherently all 'now' states are equal. Therefore, I can't claim this 'now' state is more real than a perceived 'past' or 'future' state, because they all carry the same value and logical principles.

 

[Descartz2000]

If you believe that the state of things has to be crisp and definite - something either is or it isn't - then you indeed face a logical bind. Past and future are either states that are - which ends up in the deterministic block time view where the now is an illusion - or instead only the now is real, which makes past and future the illusion.

So yes, think that way and you are trapped into mutually contradicting positions, neither of which feels right.

Which is why I stressed the further dimension to reality, the dimension of development that runs from the vague to the crisp, from becoming to being, possibility to actuality, etc. This is a traditonal idea in metaphysics even if it has become largely lost in physics.

So the past is definite (it cannot be changed) while the future is indefinite (it is still full of vague potential, a capacity for change, while also of course highly constrained because of a weight of accumulated history).

The best kind of model of this could be a scalefree network or other "edge of chaos" model where the "now" is a mix of past and future - a powerlaw mixture of the changed and the changing, islands of stasis and flux.

Look inside the "now" of the universe - which can be measured in a general way by its current temperature - and you will be able to see that it is in fact an average of local "nows".

This follows from the transactional interpretation of QM, a la Cramer, I believe.

I don't understand where the contradiction lies. Why shouldn't things be crisp and definite especially when we are talking about the macro world? Leaving QM aside, I think on the large scale most things and events are deterministic, maybe not predictable, but deterministic. So, where is this area of non 'crispness' that you talk about especially when we are referring to everyday real world events? The future is not 'open' so to speak, at least no objectively. It is open from your perspective of 'now', but this viewpoint is not preferred over any other viewpoint. If it is 'open', then your viewpoint of 'now' is more valid of a perspective, than your viewpoint in the future. yet, this is incorrect. According to Relativity, no 'now' state is more valid than any other.

 

[apeiron]

I think on the large scale most things and events are deterministic, maybe not predictable, but deterministic. So, where is this area of non 'crispness' that you talk about especially when we are referring to everyday real world events? The future is not 'open' so to speak, at least no objectively. It is open from your perspective of 'now', but this viewpoint is not preferred over any other viewpoint. If it is 'open', then your viewpoint of 'now' is more valid of a perspective, than your viewpoint in the future. yet, this is incorrect.

Take a seed. It could turn into many different potential trees - different branching patterns depending on the vagaries of soil, weather, disease, angle of sun and wind, competition from other trees. So its future state is relatively unconstrained in some regards. Its future is broadly determined (by its genetic history, an accumulation of past information) but is open, indeterminate, in its detail.

According to Relativity, no 'now' state is more valid than any other.

Yes, but this is just because time is modeled as a locally reversible or symmetric dimension. It leaves out any attempt to represent an arrow of time, a gradient. So relativity may tell the truth, but not the whole truth!