Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: Bill S on 26/05/2018 16:18:31

Title: Could there be "static" instants of time?
Post by: Bill S on 26/05/2018 16:18:31
Time and Classical and Quantum Mechanics: Indeterminacy vs. Discontinuity   Peter Lynds

https://arxiv.org/ftp/physics/papers/0310/0310055.pdf

I’ve had this on my external HD for well over a decade, and have decided to read it, or delete it.  Available time being what it is, I’ll have to take it in bits; so please have patience.

On the subject of a static interval of time, Lynds says:

Quote
Regardless of how small and accurate the value is made however, it cannot indicate a precise static instant in time at which a value would theoretically be precisely determined, because there is not a precise static instant in time underlying a dynamical physical process. If there were, all physical continuity, including motion and variation in all physical magnitudes would not be possible, as they would be frozen static at that precise instant, remaining that way. Subsequently, at no time is the relative position of a body in relative motion or a physical magnitude precisely determined, whether during a measured time interval, however small, or at a precise static instant in time, as at no time is it not constantly changing and undetermined.

In QM, a quantum is precise and indivisible, but processes that follow the rules of QM progress via a succession of quanta.  Could it be reasoned that time progresses via a succession of individually static instants?

Lynds thinks not.  He says:

Quote
We begin by considering the simple and innocuous postulate: ‘there is not a precise static instant in time underlying a dynamical physical process.’ If there were, the relative position of a body in relative motion or a specific physical magnitude, although precisely determined at such a precise static instant, would also by way of logical necessity be frozen static at that precise static instant. Furthermore, events and all physical magnitudes would remain frozen static, as such a precise static instant in time would remain frozen static at the same precise static instant. (Incidentally, the same outcome would also result if such a precise static instant were hypothetically followed by a continuous sequence of further precise static instants in time, as by their very nature a precise static instant in time does not have duration over interval in time, so neither could a further succession of them. This scenario is not plausible however in the first instance, as the notion of a continuous progression of precise static instants in time is obviously not possible for the same reason).

How logical is the reasoning, here?  Consider this:  “a precise static instant in time does not have duration over interval in time,”

What this seems to say is that an instant in time has no duration.  Theoretically, one might argue that something can exist for a period of no time; but on a practical level, that makes no sense.  Surely, if something has no temporal duration, it does not exist in time, and since it is time we are considering, that makes little sense.
Title: Re: Could there be "static" instants of time?
Post by: alancalverd on 26/05/2018 20:50:53
Semantics.

A point on a line has no length. A point on a timeline has no duration. What's the problem?
Title: Re: Could there be "static" instants of time?
Post by: yor_on on 26/05/2018 20:55:13
Well. according to Einstein time is a local definition, is it not?
So, from where would one then define those 'instants'?

Take your choice
Title: Re: Could there be "static" instants of time?
Post by: Bill S on 26/05/2018 21:22:59
Quote from: Alan
A point on a line has no length. A point on a timeline has no duration. What's the problem?

I have no problem with either of those, in principle.  However, in practice, can you show me a point that has no length, but is still there?

Similarly, a point on a timeline that is defined as having no duration may be theoretically valuable, but both the timeline, and the point are mathematical tools.  What would be a physical example?
Title: Re: Could there be "static" instants of time?
Post by: Bill S on 26/05/2018 21:33:14
Quote from: yor_on
So, from where would one then define those 'instants'?

That's one of the things I hope to glean from the article.  My own feeling is that it would have to be one's own RF.  That leaves the questions:
If the "instants" are different in different RFs, how can they all be of zero duration? 
If they are all of the same duration, how do they differ from one another?
If they don't differ, what does that say about the local definition of time?
Title: Re: Could there be "static" instants of time?
Post by: yor_on on 26/05/2018 22:21:29
That's a pretty good question Bill.
Pick a choice

A "absolute 'galactic' frame"
Or no 'absolute frame'?

If there is none, how would you go about defining those instants?
Is there a way to make them 'fit' a 'whole universe' in some objective sense, instead of local definitions?
Title: Re: Could there be "static" instants of time?
Post by: yor_on on 26/05/2018 22:29:25
The point is actually important to me
It's Alice in wonderland

You turn it around and then?
Because logic tells me that all 'instants' are the same, just as 'c' is
Well, my logic then :)

A instant becomes a clock when repeated, as defined locally
==

If you think of it, a lot of our definitions are expected to be 'objective' although they are made as local measurements/experiments. We define repeatable experiments as those that you can repeat under similar circumstances, anywhere and at any time. It doesn't state anything about what the 'universe' should be seen as, just that the experiments done should be repeatable.
Title: Re: Could there be "static" instants of time?
Post by: Bill S on 27/05/2018 00:02:17
Quote
A instant becomes a clock when repeated, as defined locally

I'm OK with that, but, is Lynds?

Quote
  (Incidentally, the same outcome would also result if such a precise static instant were hypothetically followed by a continuous sequence of further precise static instants in time, as by their very nature a precise static instant in time does not have duration over interval in time, so neither could a further succession of them.

Title: Re: Could there be "static" instants of time?
Post by: yor_on on 27/05/2018 10:45:25
Well, I'm as always of two minds :) What one can note is there is some prerequisite you have to accept to discuss it. It goes out from a notion of a whole universe in where those 'instants' either may exist, or not. That's not the 'instants' Relativity speaks of, as they must be observer dependent. So whose 'instants' should we take as a given? It's a fundamental to me, this first question. Presuming that there is a isotropic homogeneous universe, and from that also presume that what holds at one place and time will hold at another, you come down to a principle in where 'instants' should be of a same duration, if they exist. It's the idea of a 'flow' relative 'quanta of time' that's discussed as far as I get it, right?
Title: Re: Could there be "static" instants of time?
Post by: Bill S on 27/05/2018 19:43:25
Quote
Well, I'm as always of two minds

I envy people who have two!  I have only one, and I think that's wearing out.  :)

Getting busy here, but I hope to think about your comments while doing other things.
Title: Re: Could there be "static" instants of time?
Post by: Bill S on 27/05/2018 22:44:08
As I said above, I think the only “instants” we can consider are those in own RFs; but in terms of the reasoning of Lynds, this still leaves the questions in #4 unanswered.

I think the presumption that we inhabit an isotropic homogeneous universe is essential to much cosmological thinking, and that the presumption that what holds at one place and time will hold at another, follows from that. 

Does that mean that Lynds should have been more specific about the provenance of his instants?
Title: Re: Could there be "static" instants of time?
Post by: Bill S on 28/05/2018 13:28:39
Quote from: Lynds
It is not necessary for time to “emerge” and “congeal” out of the “quantum foam” and highly contorted space-time geometry’s present preceding Planck scale (Gh/c 3 ) 1/2 just after the big bang (new inflationary model), as has often previously been tentatively hypothesized.  Continuity would be present and naturally inherent in practically all initial quantum states and configurations, rather than a specific few, or special one, regardless of how microscopic the scale.

What would it mean, for time to “emerge” and “congeal”?

Emergence is change, change requires time, so time would have to precede the emergence of time; which makes no sense.

What is “uncongealed” time?   Could it be time without direction? 

How could that be identified as time?
Title: Re: Could there be "static" instants of time?
Post by: yor_on on 30/05/2018 12:42:59
I think of 'emergence' in one way more Bill. To me it means something new, as in not expected. And the question there is whether this is true? Either there exist 'jumps/emergence' or it's just us not finding the right way to follow the chain leading to a 'emergence'.

There I wonder :)
Title: Re: Could there be "static" instants of time?
Post by: Bill S on 30/05/2018 13:25:43
So, can you have "emergence" that does not involve change?
Title: Re: Could there be "static" instants of time?
Post by: yor_on on 30/05/2018 13:41:20
No

Not as I think about it anyway, if you remember a common example of a emergence is water becoming ice, having new and unexpected properties. But the question there would be if that is due to our lack of understanding. I don't know, in some way it connects to whether time is a 'flow' or 'instants', to me at least. It's the same principal question of how things work with a 'flow' then representing a more Newtonian universe in where cause and effect is traceable. And where 'instants' then would be 'jumps'
Title: Re: Could there be "static" instants of time?
Post by: Bill S on 31/05/2018 00:07:36
Obviously, “emergence” has various shades of meaning, so if by the emergence of time, we mean that time becomes visible after being concealed, or comes to prominence, after fulfilling only a minor role; then it is quite justifiable to talk of time emerging.  However, talking of time emerging in a scenario in which there was previously no time, is a cat of a different colour.
Title: Re: Could there be "static" instants of time?
Post by: jeffreyH on 31/05/2018 12:30:07
Things happen. We call these events. We can compare one event with another. One may be a projectile and the other the readout on a clock. Ultimately, we are comparing one change against another.
Title: Re: Could there be "static" instants of time?
Post by: yor_on on 31/05/2018 13:27:06
Alan made a good point I suspect. We use mathematics as the tool describing the universe, but the mathematics often use dimensionless 'points' in quantum logic, well, as it seems to me. Although each of us see and measure a possibly infinite universe having dimensions we can 'move' inside, that doesn't really tell us what someone 'outside' this universe would see looking at 'it'.

the way around it using quantum logic is then to think of it as 'waves' in a 'field', If you do that the 'field' becomes our universe, and another question should become, is such a field 'contained' in some manner?  If it is, what 'contain it'. As a slightly outrageous notion, presume that what we call 'dimensions' from an inside all are 'illusions', and that the logic creating the tangible universe we see might be 'time' :)

But that's not enough, you also need cause and effect
Title: Re: Could there be "static" instants of time?
Post by: Bill S on 31/05/2018 23:40:16
Quote from: Jeffrey
Things happen. We call these events. We can compare one event with another. One may be a projectile and the other the readout on a clock. Ultimately, we are comparing one change against another.

While this is, undoubtedly true, it doesn't address the question whether/how something might "emerge" if time were not available to facilitate the change.

Nor does it address the question of something emerging from nothing.
Title: Re: Could there be "static" instants of time?
Post by: Bill S on 01/06/2018 00:03:54
Quote from: yor_on
Alan made a good point I suspect. We use mathematics as the tool describing the universe, but the mathematics often use dimensionless 'points' in quantum logic, well, as it seems to me.
   
As I have said before, I acknowledge the use of these tools in maths, and respect those with facility in their use.  However, I’m not holding my breath while waiting for someone to demonstrate a physical example of a dimensionless point. 

Quote
Although each of us see and measure a possibly infinite universe having dimensions we can 'move' inside, that doesn't really tell us what someone 'outside' this universe would see looking at 'it'.
I assume you are not using “universe” meaning everything that exists.

Quote
As a slightly outrageous notion, presume that what we call 'dimensions' from an inside all are 'illusions',
I would say there’s nothing outrageous about that, as long as you acknowledge that the “illusions” are part of the reality of our Universe.

Quote
…and that the logic creating the tangible universe we see might be 'time' :)
Only if you regard time as an entity independent of anything else.

Quote
But that's not enough, you also need cause and effect

Why?
Title: Re: Could there be "static" instants of time?
Post by: yor_on on 01/06/2018 04:50:01
Ok, been working the tunnels all night, my free day starting and slightly inebriated, a ice cold beer and a hot bath goes very well together. :) Let's see if I can untangle the knots, but bear with me, it's just me playing with logic.

Why time is important to me

Because I equal 'c' to a (local) clock. Remember that I used the argument that "  Presuming that there is a isotropic homogeneous universe, and from that also presume that what holds at one place and time will hold at another, you come down to a principle in where 'instants' should be of a same duration. "

If you now do, agree to, those things, then 'time' is the 'universe'. You don't need 'motion' but you need a logical representation that mimic it, or if one like, is a equivalent of it. And it takes care of the 'propagation' too.

Actually you can expand on it and define it as a universe that uses relations to define cause and effect. I don't see how we can avoid causation, it exist. But if I presume that the two slit experiment is a result of the relations I also, probably, need to assume that there is some way of communication that surpass 'the speed of light'. And we have that.

I expect that one have to differ between the rules regarding mass (aka 'proper mass') and those that 'break' the speed of light (and that one isn't as clear as it sounds rereading it, it's tricky). And the way it seems to build up is through what scale you use. How does the two slit experiment 'instantly know' the way you set it up for example?  And how does the spin of one photon communicate the opposite spin as soon as you measure it. This one is about causation too https://www.extremetech.com/extreme/156673-the-first-quantum-entanglement-of-photons-through-space-and-time but in a different way as it discuss entanglements

Then there is also a importance in pointing out that the question of whether 'time' is a 'flow' or 'instants' isn't that important for my ideas. You can always divide a flow into 'instants', and possibly also find some threshold that define those.

We do know there are different rules macroscopically than what we find on a microscopic plane, aka quantum mechanics, and we also use decoherence to define where a threshold might be https://plato.stanford.edu/entries/qm-decoherence/
Title: Re: Could there be "static" instants of time?
Post by: Bill S on 01/06/2018 19:35:32
Quote from: yor_on
…..you come down to a principle in where 'instants' should be of a same duration.

That’s fine, but are these instants static in the sense that Lynds refers to in the OP?

Quote
Regardless of how small and accurate the value is made however, it cannot indicate a precise static instant in time at which a value would theoretically be precisely determined, because there is not a precise static instant in time underlying a dynamical physical process.

I’m not ignoring the rest of your post; just trying to unpick one thread at a time.
Title: Re: Could there be "static" instants of time?
Post by: yor_on on 02/06/2018 13:50:57
No, I don't think so. He adhere to a relativistic approach as I get it? The one in where you as a observer define a 'instant' by your clock. But if instants exist then we're in a 'flickering' universe. and using simple logic that also will imply 'somewhere else' from where 'someone can see it flickering. And, let's see, if you to it add that the flickering is 'observer dependent' I have to wonder who will be able to 'see' our universe at all, it imply a outside to be true I think? Then again, if you adhere to many worlds scenarios this just add up to it, extremely intricate universe in where we don't exist at all as defined from a outside, except as 'instances' :)
Title: Re: Could there be "static" instants of time?
Post by: yor_on on 02/06/2018 13:53:36
But  I don't think he's right. I prefer a universe in where Relativity is correct, it's just that we keep looking at it from a 'whole universe', that one I'm not as sure on. That's what I think he do when he uses ones local clock, and then talks about 'instants'. Einstein did the same as I think, he looked at a whole universe.
==

You might want to call it a contradiction in terms. A Isotropic homogeneous universe, in where the 'laws' are the same at every 'SpaceTime' position. But 'flickering'. Relativity do not discuss a outside as far as I know, but a 'flickering' should demand one? A simpler solution should be the one I suggested using the isotropism and homogeneous ideas we have, and then ask ourselves how we can join 'instants' of a same measure to that idea, by which I mean observer dependencies btw :)
==

although the one I really think is correct is the one the two slit experiment suggest. A complementary logic in where the observer defines the outcome by the way he sets up his experiment. A 'observer dependent' universe, but also one in where each observer relative his clock and ruler, have a same measure. Expressed otherwise. You can always divide a flow into 'instants', and possibly also find some threshold that define those. But it demands you to find a way to express this mathematically.

Hmm, rereading it. Maybe he has a point, as far as I see he's also suggesting that instants can't exist due to HUP ? That's a very valid comment as HUP is about indeterminacy. You might then go from that to define a 'instant' as being the 'outcome' though. Maybe´I should have read it more carefully.

One of the points of an idea in where instants are non existent is that you no more can use 'instants of acceleration' for example, equalizing them to a 'uniform motion'. It has a lot of implications for those wanting to simplify how to think about relativity.

Title: Re: Could there be "static" instants of time?
Post by: Bill S on 03/06/2018 15:10:41
Quote from: yor_on
If you now do, agree to, those things, then 'time' is the 'universe'. You don't need 'motion' but you need a logical representation that mimic it, or if one like, is a equivalent of it. And it takes care of the 'propagation' too.

You’ve lost me there!  I don’t see how time can be the universe.  It may be more than the tool we use to measure change, but you seem to be suggesting that it is the fundamental reality.  Convince me.  :)
Title: Re: Could there be "static" instants of time?
Post by: Bill S on 03/06/2018 15:20:13
Quote from: yor_on
But if instants exist then we're in a 'flickering' universe. and using simple logic that also will imply 'somewhere else' from where 'someone can see it flickering. And, let's see, if you to it add that the flickering is 'observer dependent' I have to wonder who will be able to 'see' our universe at all, it imply a outside to be true I think? 
Let’s see if I get what you are saying.

If instants don’t exist, our Universe doesn’t flicker.

If instants do exist, our Universe flickers.

If the Universe flickers, there must be an outside observer to observe the flickering.

If I have that right, my question is: Why the need for an observer of a flickering universe, but not a non-flickering one?
Title: Re: Could there be "static" instants of time?
Post by: Bill S on 03/06/2018 19:27:10
Quote from: Bill
Quote from: Alan
A point on a line has no length. A point on a timeline has no duration. What's the problem?


I have no problem with either of those, in principle.  However, in practice, can you show me a point that has no length, but is still there?

Any thoughts on that, yet, Alan? 
Title: Re: Could there be "static" instants of time?
Post by: yor_on on 05/06/2018 13:47:14
Heh :)

A 'flickering universe' must to be proved be observed. We can't do that, after all we're 'flickering' too :) That is if you define in to have a 'common beat'. If you don't we should be able to see it possibly? But when I think of it it is from the same ideas that have created the isotropic homogeneous universe we expect to exist. Which makes me think of it as if you excuse me, being a 'whole universe 'breathing' :) But you have a good point, after all, the universe is observer dependent.
=

It also go backs to 'instants of time' being equivalent to 'c', for me then.
Title: Re: Could there be "static" instants of time?
Post by: yor_on on 05/06/2018 13:54:06
That's the whole point of it actually, it seems to me that observer dependencies won't allow you to observe the flickering either, if it now exist. Because what you will see is your 'universe' and that one should 'breath' to your timing. And it won't help if you ask your neighbor to look, as the same must be be true for him. You might say it's a result of the logic that creates repeatable experiment.
=

And yes, that's why I think a 'flickering universe' demands a 'outside', because it seems the only way to prove it.

Looking at it from a 'whole undivideable universe' in where we all participate gives it a common beat in where we are part too, from a observer dependent universe you won't find it either. You can't have it both ways simultaneously without moving it to a cerebral plane, but that's not what I'm thinking of here. I'm just trying to see how one could prove it, which becomes another kettle of fish.
Title: Re: Could there be "static" instants of time?
Post by: yor_on on 05/06/2018 14:00:03
Time is change, motion and propagation is like paintings laid over each other, a coordinate system that needs change to create it. In that respect nothing exist without time. We define the universe through outcomes.
Title: Re: Could there be "static" instants of time?
Post by: Bill S on 05/06/2018 20:18:48
Quote from: yor_on
A 'flickering universe' must to be proved be observed.

I would certainly not argue with that; but you seem to equate it with: 

Quote
If the Universe flickers, there must be an outside observer to observe the flickering.

As I see it; the Universe could flicker, whether we could prove it, or not.  Our perception/understanding of the Universe is observer dependent, but does that mean that the reality (whatever that might be) of the Universe is in any way dependent on our observations?

Title: Re: Could there be "static" instants of time?
Post by: yor_on on 06/06/2018 04:14:18
We have repeatable experiments, that's what we've used so far to see if our hypothesis's, theory's hold. If we step away from that we will have beliefs instead. Those may be ever so convincing, but without experimental proofs they mean little scientifically, at least as I see it. So the question of a 'flickering universe' will definitely need a experiment, and how that one could be constructed? Which then leads me to a needed 'outside' as I can't see a way to construct it from 'inside' :)

And yes, the universe is indeed dependent on the 'observer', but that one could just as easily be inanimate as alive. As far as I see the universe treat everything the same when it comes to observer dependencies. You have delayed choice experiments for example. But let's assume that all pieces of their 'system' are 'observers' of whatever outcome that will be reached. Then those too are 'observing' in a sense, although not cognitively. That we can imagine ways to set up such experiments doesn't mean that they exist in a vacuum, as they say (that as everything indeed exist in a vacuum:)

https://briankoberlein.com/2015/06/04/real-and-unreal/

(One thing I don't agree with in the article though is the use of the word 'quanta'. It leads one to think of it as 'something', to me that is wrong. It's about indeterminism.)

One point more, there is naturally that third option in where you as a observer define some far away 'flickering frame' relative your own. That would be a very weird idea as one then differ observer dependencies by what distance it exist on relative the observer, so yea, there are several reasons why I don't believe in that one. One simple is that there isn't any such frame found :)
Title: Re: Could there be "static" instants of time?
Post by: Bill S on 10/06/2018 19:41:47
I’ve been absent for a few days for a number of reasons, one of which was my second cataract Op.  Great success so far.
I apologise if I have missed anyone’s questions or failed to respond to relevant points.

I have had a bit of time for thinking, and have some thoughts in my head – a sort of summary of what I have gleaned from this thread.  Now that I can see  ;D, I’ll try to post these thoughts soon. 

In the meantime, does anyone have any thoughts about that “ point that has no length, but is still there”?




Title: Re: Could there be "static" instants of time?
Post by: Bill S on 10/06/2018 22:53:07
Quote from: yor_on
So the question of a 'flickering universe' will definitely need a experiment, and how that one could be constructed? Which then leads me to a needed 'outside' as I can't see a way to construct it from 'inside' :)

Let's be clear about what I'm saying/not saying.

I'm not saying I think the Universe flickers.
I'm not saying I think the Universe doesn't flicker.
I'm not saying I think you would not need an outside observer to establish flickering/non-flickering.

I am saying I think you cannot state categorically that either is the case, just because you cannot devise an experiment to establish the reality of the situation..
Title: Re: Could there be "static" instants of time?
Post by: Bill S on 10/06/2018 23:05:52
I've not given the paper the time/attention it undoubtedly deserves, but if I hang on until I've done that, the subject may well be long gone.

I've split the thoughts into two parts.  This is the first.

Summary: Considering time as flowing.

1.  Are static instants defensible?   
No.  Each instant would have to be separated from the preceding and following instants.
What would separate them?  Not time, that would make no sense.  Not space, because time would be required to traverse the space. 
Would it be “nothing”?  That would be tantamount to saying they were not separated.  How would this differ from continuous flow?

2.  Lynds says: “It is the relative order of events that is relevant, not the direction of time itself.”  If this is true, which seems reasonable, then dividing physical activity into “events” would make no difference to the apparent flow of time.  Time would continue during and between the events.

3.  Time cannot have “emerged”.  Claiming that this could happen would imply the existence of “time” before time; which is absurd. It would also imply the realisation of change without any possibility of measurement of that change.

4.  Is it possible that time has always existed?  There are many examples of arguments for “eternal” time; Eternal inflation being one of the prominent contenders.  These lines of reasoning seem to make much more sense than “emerging time”.  However, there is a serious problem that arises on closer consideration.  It touches on the relationship between time and eternity, and is, perhaps, an unnecessary diversion at this point.

Comments appreciated, please.  Be brutal!
Title: Re: Could there be "static" instants of time?
Post by: geordief on 16/06/2018 02:06:18
A point on a line can perhaps be viewed as a limit as the extent of the line encompassed approaches zero.

That is not how it is defined mathematically so far as I know but maybe it is mathematically vigorous .

If so then a point in time could be seen in the same way , as a limit.

Even if somehow a "static point in time or spaces could be  located it would, in the physical world disappear  instantaneously as the world around it  interacted with it.

Of course mathematical points in spaces or time can perhaps be treated as static as mathematics only models the physical world and so has "artistic license"
Title: Re: Could there be "static" instants of time?
Post by: Bill S on 16/06/2018 13:51:38
Quote
Of course mathematical points in spaces or time can perhaps be treated as static as mathematics only models the physical world and so has "artistic license"

Beautifully put! 

Mathematics must be the best tool we have for understanding the Universe; but maths is not God.  If someone could produce good evidence that some "intelligence" designed and created the Universe using mathematical rules, I would, of course, reconsider my position, but in the meantime, I'll go with the thought that the Universe is as it is, for whatever reason, and maths is the (astoundingly successful)  creation of the human mind.  I wash I had a better grasp of it.  :)   
Title: Re: Could there be "static" instants of time?
Post by: Bill S on 16/06/2018 15:46:07
Summary: Considering time as a measuring tool.

1.  Only physical change is relevant.  Time is simply a device we use to make sense of, and to measure this change.  As this is what Lynds seems to be saying, it must be that his “preoccupation” with the idea of static instants is an attempt on his part to address the “misconceptions” of others.
The development of the concept of linear time was necessary for rational beings to make sense the exigencies of the Universe we observe. 

2.  Does time “flow”?  We can, and many authors do, treat time as though it were flowing from past to future.  We can also treat time as being static and consider that we are passing through it.  the “tensed” and “tensless” views of time; or McTaggart’s “A Series” and “B Series” examine these two viewpoints.  Neither of these viewpoints has any validity if time does not exist as an “independent” entity.

3.  The necessity for eternity remains.  If it is physical change that is relevant, there must always have been change.  It follows that there must always have been something to change.

4.  An infinite multiverse, eternal inflation, or even “Platonia”, seem to offer explanations for an eternal “something”, but none of these actually addresses the problem of changes in eternity/infinity. 
Title: Re: Could there be "static" instants of time?
Post by: Bill S on 06/07/2018 19:11:16
Re: Could there be "static" instants of time?

« Reply #3 on: 26/05/2018 21:22:59 »

Quote from: Alan
A point on a line has no length. A point on a timeline has no duration. What's the problem?

Quote from: Bill
I have no problem with either of those, in principle.  However, in practice, can you show me a point that has no length, but is still there?

Similarly, a point on a timeline that is defined as having no duration may be theoretically valuable, but both the timeline, and the point are mathematical tools.  What would be a physical example?

It's well over a month since I asked these questions, and a little later, tried to involve others.

If these questions arise from my ignorance, and if I assume that a complete lack of response indicates that no one can find an example, I might go on to assume that there is no answer; thus the "tide of [my] ignorance" would need "stemming"
Title: Re: Could there be "static" instants of time?
Post by: geordief on 07/07/2018 09:56:05
The only way we can access the concept of "physical" is by way of measuring** it (or taking it on faith).

"Measurement" has mathematics hardwired into it and so we are allowed to incorporate zero  measurements into it.

But these measurements need to be repeatable and predictive to have any validity  and I am unaware of any cases where that has applied.

Lack of evidence does not mean proof of non-existence but it is a good working hypothesis (especially if nothing of value can be assumed  if this does exist (apart from shutting down the universe like sand on the beach :)  )

Personally I am happy to assume the impossibility of static moments in time as this understanding  seems to open up  doors of understanding that the contrary understanding would close off.

Actually come to think of it ,was there not some finding recently where a system was built that went into some kind of repetitive "time loop"? Not sure if that qualifies in any way as an independent "time space" (can't find the link just now but maybe others remember  that piece of science news over the past 6 months or so)


**even our bodies ,with their sensory equipment are just rough biological mathematical tools,arguably.
Title: Re: Could there be "static" instants of time?
Post by: Bill S on 08/07/2018 00:20:09
All good and interesting stuff, Geordief, but if the answer to the question is in there, it eludes me.

The question is straight forward, but the proffered answers always seem to amount to what my mother used to call "explaining something away"   
Title: Re: Could there be "static" instants of time?
Post by: geordief on 08/07/2018 10:15:48
Well I was only giving an "opinion piece" as I can't answer the question with any degree of authority (my opinion was that you will not find such an example as it would probably "break causality" which is the fundamental bedrock   of the physical nature of the universe as we seem to experience it)

There are objects called "point particles" which I have heard about (without being able to understand as yet) but I do not think they would be the example you are looking for ,even if at first  they might seem to fit the bill.
Title: Re: Could there be "static" instants of time?
Post by: Bill S on 08/07/2018 14:26:48
Quote from: Geordief
...my opinion was that you will not find such an example...

We certainly seem to be on the same page here.  I wouldn't even credit it with breaking causality. I think it's the ultimate oxymoron. 

I've no doubt that point particles, and other zero dimensional "objects" play a valuable role in maths and theoretical physics, but physical examples are a bit like Father Christmas; lots of impostors, but no "real thing". 
Title: Re: Could there be "static" instants of time?
Post by: geordief on 08/07/2018 15:55:17
Quote from: Geordief
...my opinion was that you will not find such an example...

We certainly seem to be on the same page here.  I wouldn't even credit it with breaking causality. I think it's the ultimate oxymoron. 

I've no doubt that point particles, and other zero dimensional "objects" play a valuable role in maths and theoretical physics, but physical examples are a bit like Father Christmas; lots of impostors, but no "real thing". 
I just assumed I had not yet understood why they are actually termed point particles **and that my present level of understanding led me to imagine (perhaps as mathematical objects) them as other than what they will hopefully be seen as when the model has been understood.


I think when one is attempting to learn a model that one always creates a false picture of it in ones mind's eye  until one gets close enough to see it for what it is. (it is hardwired into  our way of thinking and learning--I always thought Hendrix said "excuse me while I kiss this guy" instead of "the sky"  :) )


**because they have zero dimensions of freedom (in the model)  is the closest I think I have got yet.
Title: Re: Could there be "static" instants of time?
Post by: Bill S on 08/07/2018 23:25:01
Quote from: Geordief
I just assumed I had not yet understood why they are actually termed point particles **and that my present level of understanding led me to imagine (perhaps as mathematical objects) them as other than what they will hopefully be seen as when the model has been understood.

I suspect that they will never be more than mathematical tools, but, undoubtedly they are of real value in theoretical physics.  As such, even pedantic old farts, like me, have to acknowledge them.

BTW, I like the mondegreen. :)
Title: Re: Could there be "static" instants of time?
Post by: evan_au on 09/07/2018 10:56:06
I just listened to this lecture by Carlo Rovelli (of Quantum Loop Gravity fame), on the subject of Time.
Presented at the Royal Institute in May 2018 (1 hour).
It's for a fairly general audience, but it was good to hear an expert explain his ideas in plain language.
At the end, a boy asks "what is half a Planck unit of time?". So obviously something had gotten across!

Audio: http://www.abc.net.au/radionational/programs/bigideas/the-mystery-of-time/9790674
Video:
Title: Re: Could there be "static" instants of time?
Post by: Bill S on 09/07/2018 12:53:09
Thanks Evan.  I must try to fit it in soon.
I've just been given Rovelli's book, The Order of Time.  All I need is time to read it. :)
 
Title: Re: Could there be "static" instants of time?
Post by: Bogie_smiles on 06/09/2018 14:41:36
I watched it and it was timely  :)
Title: Re: Could there be "static" instants of time?
Post by: yor_on on 06/09/2018 15:40:45
I don't think they are mathematical tools Bill. They should be what creates dimensions, and that's what you need if you want to measure. Particles that are measurable is a containment (atom) inside those dimensions, well, possibly :) up quarks down quarks, mesons and baryons. The electron f.ex is a 'point particle'.
=

then you have gluons that are massless messenger particles for the strong nuclear force, interacting with quarks and itself, according to quantum chromodynamics (QCD).  "The strong force binds quarks together in clusters to make more-familiar subatomic particles, such as protons and neutrons. It also holds together the atomic nucleus and underlies interactions between all particles containing quarks." https://www.britannica.com/science/strong-force

btw: 'nuclear' just means a nucleus in this terminology, although we use the term in other ways too.