Of course. I am asking why, if time really *is* every process, how is it possible that it's state can be communicable with a single number? For instance, seconds since the big bang? Or, from the discussion with apokrisis, 2.725K?

I would say that the clock actually IS time, just as all processes (all change/motion) are. — Terrapin Station

But a process is an unfolding causal pattern. So it involves changes, but also materiality and location.

What you may mean is that in talking about time at the cosmological level, we need to be able to see it as an immanent aspect of the Universe considered as a process (a disspative process for example) rather than something transcendent of existence itself (in the way Newtonian time is).

So in that light, we need to find what changes least about the process that is the "Universe coming to be", and thus can stand as our global static backdrop for local acts of measurement.

In modern physics, the Planck scale triad of constants gives us that kind of fundamental dimensional yardstick. So time or duration (as measured by any clock) is derivative of a relation between h, G and c - the basic units of quantum action, gravity's strength, and the speed of light.

For "time" to "pass", there must be an effective distance as scaled by the relation: h x G/c. Or more accurately, a unit of Planck time is t = square root of h x G/c^5.

That is, starting from the Big Bang, the Universe must have grown big enough, and flat enough, for the quantum spreading and cooling of its contents to have begun - the first tick of the thermal clock.

So from a Newtonian frame of reference, we talk about the Big Bang starting at 10^-44 seconds. But that is imagining time in a way that is detached from existence as a thermal quantum process. It is imagining the Big Bang as happening in time as opposed to the Big Bang being the first tick of time.

From the Big Bang point of view, time starts from an already physical size - the one where there is already also a maximum local energy density or heat, and a minimum possible spatial extent.

A thermometer measures temperature and perhaps represents a conception of temperature, but in no way can you say a thermometer *is* temperature. — hypericin

And I didn't say it "is" temperature.

A clock is a device that is meant to locate events in time. So - to the degree a clock seems to work - this is due to a presumption about what "events in time" means.

You keep asking about "time itself", as if that notion made sense. It doesn't. It's the philosophical equivalent of the sound of one hand clapping.

But we can talk about local change being measured against a backdrop of no change. We can talk about differences of rates. So now all we need is a backdrop which has usefully minimal change in terms of the aspect of change we are interested in measuring.

With Newtonian mechanics - the laws of masses in motion - that resulted in the kind of time that you think "is time". But that notion of time turned out to be not very realistic once we started measuring the Universe at hotter/smaller scales, or larger/colder scales. It turned out that at a more general scale, time, space, momentum and energy are all entangled - as the Planck scale constants show.

Of course we can still measure time in Newtonian fashion with a clock. But we now have to remember to include corrections as we start to approach the extremes of scale. So if you accelerate a clock towards the speed of light, you know it is going to tick slower.

Yet it would be great to have a model of time, a way of measuring change, that doesn't have to involve a collection of corrections - especially once we get down to the level of a theory of quantum gravity.

Of course. I am asking why, if time really *is* every process, how is it possible that it's state can be communicable with a single number? For instance, seconds since the big bang? Or, from the discussion with apokrisis, 2.725K? — hypericin

The single number is just your way of locating yourself as an event in a wider sense of passing time.

So if you have a model of the Universe as a bath of radiation spreading~cooling at a geometrically determinate rate, then you can hope to pin-point your location within that cosmic history by measuring the current CBR temperature (or equivalently, the current average energy density of outer space).

So you don't measure time in some direct sense - as time is not itself a thing. What you measure is a local surrogate of the globally unfolding process you believe to be taking place.

An actual clock with hands and a face is a surrogate for Newtonian time in that it presumes you can regulate the continuous uncoiling of a spring with a system of toothed cogs and an alternating escapement mechanism - the physics of that will work fine because the Universe is not so hot that the clock melts into radiation, or so cold that there is no available energy to wind it up.

So a clock as a measuring device presumes that time actually is a detached constant backdrop with no local entanglements with the device doing the measuring. But again, accelerate that clock towards c and you will find it always was in fact entangled with that "detached" backdrop. So as a model of time passing - a means of locating events in time - it isn't really getting at the fundamental level of what is going on.

Well, if we imagine that we really know "seconds since the big bang," and that doesn't differ relativistically, the way we know it is simply that we're measuring a particular process--in this case, universal expansion, where we have (mathematico-physical) conventions for figuring how the expansion has changed as it's gone on, relative to the process that we count as seconds (which we could just define as the ticking of a second-hand of a clock, or more precisely in SI terms, 9,192,631,770 (9.192631770 x 10 9 ) cycles of the radiation produced by the transition between two levels of the cesium 133 atom).

Re the CMB, we're simply measuring temperature at present.

But a process is an unfolding causal pattern. So it involves changes, but also materiality and location. — apokrisis

Yeah, processes are of material, and they have locations. That's not an objection to my view (in my opinion (re your "but")).

rather than something transcendent of existence itself (in the way Newtonian time is). — apokrisis

I don't buy that anything is "transcendent of existence itself." That idea is incoherent on my view.

In modern physics, the Planck scale triad of constants gives us that kind of fundamental dimensional yardstick. — apokrisis

That wouldn't be about what time is versus what it isn't, but what process we prefer to use as a standard for measurement.

For "time" to "pass", there must be an effective distance as scaled by the relation: h x G/c. Or more accurately, a unit of Planck time is t = square root of h x G/c^5. — apokrisis

For time to pass, there simply must be any motion/change/process. If we want to say that "Planck time" is the minimum possible motion/change/process, that would work.

Yeah, processes are of material, and they have locations. That's not an objection to my view (in my opinion (re your "but")). — Terrapin Station

So you accept my "but" in the sense of dropping the claim that "time just IS process"? At most, time is just one of a combination of abstracted limits we use to describe the Cosmos as a dynamically-evolving process - the others being principally space, matter and energy?

I don't buy that anything is "transcendent of existence itself." That idea is incoherent on my view. — Terrapin Station

Yes. But it is useful also to mention that to explain the Cosmos, we have to imagine standing outside it. Or at least standing at its absolute limits.

So the trick for modern physics is now to establish an immanent model of cosmic existence in which "time" is an emergent limit, not a Newtonian-style transcendent limit.

Understanding the deep epistemic issue is how we can hope to untangle the ontological presumptions the OP makes.

So time in the modern sense is about two things.

It is about the possibility of history. Things change in some global (entropic) direction.

And it is also about the possibility of change at different local rates. In a radiative state, everything is happening at c and so it is a pretty much timeless state. There is only a single speed. But when the electro-weak symmetry breaks, the Higgs mechanism is turned on, you then get the new possibility of masses moving with any speed between c and absolute rest.

So now there is a world of very time-ful histories. Every massive object can tell its own personal Newtonian story. Talking about "time" starts to have real meaning - in the way we more normally think about it.

But then at the Heat Death, once massive black holes have fizzled away the last any matter, returning it to timeless radiation, talking about local rates of change will lack material meaning. There will be nothing around that is moving slower than c to measure. And even radiation itself will no longer continue to get cooler via metric expansion and red-shifting. Even that last measurable index of change will have dissolved away.

So time starts with a bang and ends with a whimper. And for a while in-between, it has a bit of extra material richness in terms of not everything unfolding in vanilla process fashion. There is some added thermal complexity to the description of things.

So you accept my "but" in the sense of dropping the claim that "time just IS process"? — apokrisis

What?? No. That processes are "of material" and have locations doesn't amount to time not being process(es).

At most, time is just one of a combination of abstracted limits we use to describe the Cosmos as a dynamically-evolving process - the others being principally space, matter and energy? — apokrisis

It's certainly not (just) a description. Of course, insofar as descriptions are processes, it's fine to note that it's that process.

Yes. But it is useful also to mention that to explain the Cosmos, we have to imagine standing outside it. — apokrisis

I wish I could somehow ban all "explanation" talk. ;-) I don't know if I agree with your comment there, but "explanation" is vague.

It is about the possibility of history. Things change in some global (entropic) direction. — apokrisis

I don't at all agree with tying time up with entropy. If entropy didn't obtain, or if it were different than it obtains, that wouldn't affect time in any way.

What?? No. That processes are "of material" and have locations doesn't amount to time not being process(es). — Terrapin Station

So you choose incoherence? You are not even wanting to say time is a property of a process. or some such. You are simply conflating terms in way that makes no sense of a relation about acts of measurement and what is claimed to be measured.

I wish I could somehow ban all "explanation" talk. ;-) I don't know if I agree with your comment there, but "explanation" is vague. — Terrapin Station

Explanation is causal talk. We construct models of causal relations that are meant to describe the esssence of the structure, process or system in question. And from those models, we know what to measure so as to particularise those models. We know how to plug numbers to make the equations do something useful.

So proper explanation is the least vague of human activities.

I don't at all agree with tying time up with entropy. If entropy didn't obtain, or if it were different than it obtains, that wouldn't affect time in any way. — Terrapin Station

Yes. If things were different, then they would be different. Brilliant deduction!

Now show me why one would believe entropy doesn't obtain - the second law of thermodynamics being the most fundamental known constraint on material existence.

Perhaps you have a perpetual motion machine, or a time travel machine, that might make me start to suspect the second law?

So you choose incoherence? — apokrisis

Hello irony.

Certainly I don't think it's incoherent.

You are not even wanting to say time is a property of a process. or some such.

That's right, because it IS process(es). It's identical to that, identical to process/change/motion.

You are simply conflating terms in way that makes no sense of a relation about acts of measurement and what is claimed to be measured.

I'm trying to avoid responding with "I don't know what you're saying there," because frequently I don't really know what you're saying, but I'm not sure how to respond to a comment about "making sense of a relation about acts of measurement and what is claimed to be measured." That's not clear to me.

Explanation is causal talk. We construct models of causal relations that are meant to describe the esssence of the structure, process or system in question. And from those models, we know what to measure so as to particularise those models. We know how to plug numbers to make the equations do something useful.

So proper explanation is the least vague of human activities. — apokrisis

"Describe" has just the same problems, on my view. There are also problems with "essence" and of course "proper." Re "we know what to measure so as to particularize" . . . I just don't know what you're saying again, but if it's just "we can make the equations do something useful" I have no problem with that. Various models etc. are instrumentally useful, sure.

Yes. If things were different, then they would be different. — apokrisis

What I said is that time wouldn't be affected if entropy were different. Time doesn't imply anything about entropy. And I'm not deducing anything. <sigh>

Now show me why one would believe entropy doesn't obtain — apokrisis

I didn't say anything pro or con about whether entropy obtains. I was telling you why I don't agree with associating time with entropy.

Time doesn't imply anything about entropy. — Terrapin Station

That's right, because it IS process(es). It's identical to that, identical to process/change/motion. — Terrapin Station

So I am wasting my time because any argument I offer is going to be "rebutted" by your un-argued assertions of personal belief?

Fine.

Yep, the Big Bang exactly represents the situation of a wind up toy. Your argument is devastating. — apokrisis

Well, you haven't answered the question, how does it get up to speed, so that it can start slowing down? A wind up toy accelerates rapidly until it reaches peak speed, then it starts its steady decline. What you have described is just the steady decline, the Big Bang being the fastest, so it's not like a wind up toy at all (even disregarding the fact that the toy requires someone to wind it up). Is the rapid acceleration supposed to be prior to the Big Bang?

You keep asking about "time itself", as if that notion made sense. It doesn't. It's the philosophical equivalent of the sound of one hand clapping. — apokrisis

Why does "time itself" not make sense for you? For this to make sense, all one needs to do it is to consider time as the necessary condition for change, rather than as TS says, change is the condition for time. There is no reason why the latter should be preferred, but there is reason to choose the former. We can conceive of time passing without any change occurring, yet we cannot conceive of change occurring without time passing. So "time itself" is not at all a nonsense notion.

Well, you haven't answered the question, how does it get up to speed, so that it can start slowing down? A wind up toy accelerates rapidly until it reaches peak speed, then it starts its steady decline. — Metaphysician Undercover

Your wind up toy first has to overcome the inertia of being at rest. And even before that, someone has to wind it up, and set it down on a surface where it can start to react to the forces applied.

And then its speed declines as the countering force of friction comes into play. If your wind up toy was in a frictionless world, it could spin or roll forever (as long as it wasn't attached to its internal spring or whatever that becomes another brake).

Is the rapid acceleration supposed to be prior to the Big Bang? — Metaphysician Undercover

That's what God is for. :-}

Remember even in talking about the Big Bang in this cartoon fashion, it could be the Newtonian case that "nothingness" was coasting along inertially with no net applied force - no acceleration source - and all that had to happen was the sudden appearance of friction. Or entropification in other words.

We can conceive of time passing without any change occurring, yet we cannot conceive of change occurring without time passing. — Metaphysician Undercover

But that is what I said. We conceive as time in the backdrop sense of what is no change. Or at least, the minimal imaginable change. And then events are the local changes that stand out against an unchanging backdrop in some sense.

So why do you say "time itself" makes no sense then? Can't we conceive of the backdrop without the events in the foreground?

So why do you say "time itself" makes no sense then? Can't we conceive of the backdrop without the events in the foreground? — Metaphysician Undercover

That's my point. No I can't. An absolute lack of change makes no sense to me. What kind of thing is that?

But I can easily imagine a reciprocal deal where a backdrop relative lack of change allows there to be a foreground relative presence of change. So events and their contexts can be distinguished in the various ontically basic ways familiar from metaphysics.

If there is stasis, there can be flux. And vice versa. Each makes the other a possibility by the possibility of its own existence.

So I am wasting my time because any argument I offer is going to be "rebutted" by your un-argued assertions of personal belief? — apokrisis

Surely you don't believe that you're presenting anything like formal arguments and not just forwarding personal beliefs?

Not that I'm implying that you should be presenting something like formal arguments, but apparently you think that's what we should be doing, and I can only guess that you're under some delusion that you're doing that contra the nature of my own comments.

That's my point. No I can't. An absolute lack of change makes no sense to me. What kind of thing is that? — apokrisis

Well, time is just duration, so every change requires a duration of time which is appropriate to that change. Now, imagine a period of time which is a lesser amount of time than that required for the fastest change. In other words, imagine a period of time which is so short that no change could possibly occur in that very short period of time. Then you have conceived of time without change.

You're a waste of space. :)

Well, time is just duration, so every change requires a duration of time which is appropriate to that change. Now, imagine a period of time which is a lesser amount of time than that required for the fastest change. In other words, imagine a period of time which is so short that no change could possibly occur in that very short period of time. Then you have conceived of time without change. — Metaphysician Undercover

But that is precisely the argument by which talk about durations less that the Planck time is considered to be physically meaningless. The Planck scale tells us what the smallest possible unit of change is. And its already "larger than zero".

This was unimaginable to Newton. It remains unimaginable for most people still as "quantum mechanics can't be understood". And yet it is now a fundamental fact of modern physics.

If time is every process in the universe, then how is a single number sufficient to tell us the current state of time? — hypericin

Here's a slightly different take on things: time does not only *not* flow (which I think you may have realised), but it is *not* an observable under quantum mechanics either. Rather, time exists in quantum mechanics as a non-physical parameter upon which observables and states depend. As such it is a relic of classical physics, and presumably will disappear under quantum gravity.

Progress along these lines was made in the 60s and more in the 80s. The remarkably beautiful solution that was discovered is that the universe as a whole is at rest. i.e. the quantum state of the universe is in an eigenstate of its Hamiltonian, which frees the wavefunction and observables from any time-dependence.

Because the universe is in an eigenstate of its Hamiltonian, it is not in the eigenstate of the position of hands on clocks, or any other observable that humans might use to tell the time. Rather, the universe is in a superposition of such eigenstates, whose eigenvalues are different hand positions! Thus time is a correlation phenomenon.

Amazingly, there has been recent experimental support for this solution to the nature of time:

https://medium.com/the-physics-arxiv-blog/quantum-experiment-shows-how-time-emerges-from-entanglement-d5d3dc850933

But that is precisely the argument by which talk about durations less that the Planck time is considered to be physically meaningless. The Planck scale tells us what the smallest possible unit of change is. And its already "larger than zero". — apokrisis

So the point now, is that physical change requires a Planck time duration, but we can still conceive of a time period shorter than this. In this time period no physical change is possible. Therefore we can conceive of time without physical change. Duration less than Planck time might be "physically meaningless", but it is not philosophically meaningless, and it should be considered as a logical possibility, in philosophical speculation.

We have a very similar question with respect to space. Is empty space, space without substance, possible? Or, is space just a conception, the means by which we measure existing things? The argument above demonstrates that time without physical change is possible, but can we do the same thing with space? If not, then space and time are radically different. The problem which occurs with our conception of space, is that we assume a dimensionless point, as a means for measurement, and this inclines us to believe that the dimensionless point is spatial, when it is not. Then one might be inclined to allow that a physical object could occupy a dimensionless point, but in doing so, there is inherent contradiction.

You're a waste of space. — apokrisis

I have an equally lofty opinion of your contributions. ;-)

Now children, let's stick to the topic.

Time is a measure of a human construct of a nature that is truly immeasurable.

Time has no speed but it has " flow " or direction. Time in itself it's a concept, an idea that we created in order to organize our daily lives and activities. So therefore we divided it into every notion of measurement available today, from the Ancient "billions of years of evolution" to the nasty nanoseconds and beyond.

But what your body feels when you wake up at 6am is different from what my body feels if I wake at the same hour, because for both of us time being relative it interacts differently with each of us. ( at least our perception of it )

Why do some people who are 5y old have the biological age of a 7y old or a 3y old ?
Considering some organisms evolve faster then others or at a faster pace, how would we choose to date someone who is 5years old (chronologically) but has the biological age of a 7y old ? What would be the correct way to say it's age?

Try this for a size:

Theory of relativity, backed by some proofs, says time is relative, not absolute. The concepts of space and time do not apply to energy. We see that the light that leaves the sun arrives here after 8 and half minutes, but the time itself does not spend any time in the journey; it arrives here at the same time it leaves the sun. This takes us to some interesting conclusions. Let us say that two events occur, one on the earth and the other at our nearest star, which is 5.4 light years away. The event on the star is 5.4 years in our future and the event on the earth is in the future of the star by 5.4 by light years.

Sorry, I meant "the light (not the time) that leaves the sun arrives here after 8 and half minutes."

General and Special Relativity are weird beasts. Special Relativity claims that there is reciprocity in all frames and references and General goes on to say just the opposite, the accelerated frame is privileged and time will allow down. Nothing like two cherished theories contradicting each other and from this produce all kinds of other paradoxes.

For this reason, I reject the idea that Relativity in any form has any ontological basis. All they do is resolve some measurement problems with the Lorentz Transformations.

Real time (duration) has nothing to do with clocks creating movent in space. Duration is what we experience individually as humans. Trying to determine simultaneity of experiences is a separate issue which science is involved with.

For this reason, I reject the idea that Relativity in any form has any ontological basis. All they do is resolve some measurement problems with the Lorentz Transformations. — Rich

Why do you like quantum field theory then, as this is relativity based?

As far as I understand, they are separate and distinct theories that have yet to be unified.

Time itself has no speed. — hypericin

Speed of time makes sense to me.

Firstly, we have the subjective perception of time you mentioned - when we're bored time passes slowly while time speeds up when we're having fun. If I were to offer an explanation it would be that our biological clock speeds up or slows down as the case may be, resulting in the feeling of time speeding up or slowing down. However, this is subjective in the sense that it has to do with perception rather than time actually changing speed.

Secondly, my rudimentary understanding of the theory of relativity informs me that travelling at high velocities makes time slow down. However, I don't know if we can increase the speed of time in an objective manner. What is slower than just sitting in one place?

Speed of time makes both intuitive and scientific sense.

Such a radical change in the speed of time would be both irrelevant and undetectable. — hypericin

Indeed if speed of time changes universally and proportionately then it wouldn't be noticeable; therefore it's inconsequential. However, if the speed of time is local and disproportionate then it is relevant - think of the twins paradox (relativity).