In it, [Shannon] made a quick calculation to determine how many different games of chess were possible, and came up with the number 10^120. This is a very, very large number — the number of atoms in the observable universe, by comparison, is only estimated to be around 10^80. — CuriosityStaff

Off topic: Shannon miscalculates. The average sensible game might last 80 moves, but the average legal game averages about 5000 moves, so the number is more like 10^400.
The number of atoms in the visible universe is far different from the number of atoms in the universe, and the huge chess number is less than the latter. I hate such comparisons to that or 'grains of sand' and such.

On topic:The game of tic-tac-toe seems to have human countably many games, and this doesn't change the subject being discussed. The size of the number is irrelevant.

@kill jepetto:
The moves are possibilities yes, but not random. They're totally determined and the number of legal chess games or positions is quite defined and some exact finite number. Kippo points this out.

There are a finite number of them if you disallow repeat configurations. — Kippo

The rules do not allow repeat configurations (beyond 2), so such games would not be legal games. There is also a max length game, so the count is finite in that direction as well.

- - -

So do these games 'exist'? I suppose that depends on how one defines what it means to exist, and what things qualify as existing by that definition. I'm a relativist, so thing 1 exists to thing 2. Thus I might say that all of them exist as abstractions to humans (I can distinguish two different games from each other, or tell if two games are the same one), but they don't exist as abstractions to a rock since rocks seem not to make those abstract distinctions. That answer is consistent with my definitions, but there seems to be no correct definitions.

My original point was that I cannot make sense of the notion of unchanging phenomena, so "phenomena changes" is a tautology that says nothing. One might as well have said "phenomena is phenomena" or "change is change".

So to my mind, there isn't room for two concepts, namely that of phenomena and that of temporal change. — sime

The two words are different. Phenomenon implies an experienced thing, whereas change does not imply experience. So two concepts, since it makes sense to speak of non-phenomenal change.

'Temporal change' is not necessarily the same as change. Perhaps Terrapin thinks otherwise, since my example of a non-temporal change was dismissed. But equating change to only temporal change seems begging the equality of change and time, not evidence of two being the same thing.

I think change is simply a difference in one variable as a different variable is altered. So one can plot the brightness of my house paint over time, but not necessarily over time, and it presumes a sort of identity of the thing labeled as 'the brightness of my house paint' that can be evaluated at different points in the variable being altered.
Then also, if my house doesn't fade, then the brightness is not a function of time, and it is meaningless to speak of the time at which the brightness of it was value X.

Again, comparative difference is not the same thing as change. I pointed that out with the atmospheric density example. — Terrapin Station

Ah, a different definition of change. Perhaps that is the fault in my example.

Got to go for now.
If time was distinguishable in the million-decay example, then you could distinguish the events running forwards (with half of the decays happening before the first half life) from the scenario in reverse, with most of the state changes happening near the end.

How did your example show that? I certainly didn't agree that it showed that. — Terrapin Station

You can measure change: A count of the particles that have decayed. You have not proposed a way to measure time from that.

I brought up effects and differences and distinctions and such. It is my counterexample.
My example showed something where change was quite measurable but time was not, and if the two were ontologically the same, then if you could measure one, you should be able to measure the other.

My proposal has absolutely nothing to do with effects on anything or distinctions between systems. — Terrapin Station

OK, I was finding inconsistency with "I'm saying that what time is ontologically is change or motion". Your 'proposal' is perhaps something else. I was finding a counterexample to the quoted statement there.

Without an argument, it just seems like arbitrary ideas that have a non sequitur connection with what I'm claiming. — Terrapin Station

I'm not proposing anything. I'm finding inconsistency in your proposal.

This is what I wrote: "I don't really understand what you're asking there. Because I don't understand how you're using "meaning" really. If you're literally talking about semantics, meaning is subjective. It's a mental act of association. So are you asking if someone (who?) performs associative acts in that situation? " — Terrapin Station

OK, I think I described how I'm using the word in my prior post.

And then you responded with something about "simulation" for some reason.

Heh... I read you wrong. You said 'situation', not 'simulation'. So much for the eyes.

So are you asking if someone (who?) performs associative acts in that situation? — Terrapin Station

There is nobody performing acts in my scenario. There were only the million particles.

If you want to make an argument to the effect of "time can only be change if that (that=maybe time, change--whatever you'd need) has an effect on something" or "time can only be change if there is a distinction between a system with x and a system without x" or whatever you'd want to claim, then I'd check out the argument, but you'd have to make the argument.

I didn't really define time. I just brought up points that seem to find flaw in equating time with change.

If anything, time seems to be meaningless without change, but change is not necessarily meaningless without time, so change is arguably more fundamental. Meta might think otherwise since he asserts meaning to time without change, but I find that scenario to be indistinguishable from the same lack of change without the time.

You're ignoring the issues I brought up re "meaningful." — Terrapin Station

What post again? My take on something being meaningful is that X is meaningful if there is a distinction between a system with X and a system without X. A distinction other than the presence of X.

So I can assert that all hairs on my head have a virtual serial number, and sure, that is distinct from a universe without that because the hairs there don't have a virtual serial number, but there is no distinction to me. I cannot test for which universe I'm in. The serial numbers have no effect on anything. Thus they are not meaningful, in the way I mean that word.

You were positing something decaying at different speeds where there's only that particle decaying? That wasn't clear from your earlier comment. — Terrapin Station

I had one particle at first, but immediately moved on to the example of a million such particles.

"At different speeds" would be nonsensical in that situation. "At different speeds" has to be relative to another change.

Agree. My example illustrates that: change without meaningful time. Time is not equivalent to change.

It's always based on some set of changes. — Terrapin Station

Yes. The changes are the particles that have already decayed, and the ones that have not. There is nothing else to go on.

You posited a change in the universe. So it would be whatever you assign to that change.

The change is the decay of one of the particles. Not sure what you're thinking I'm assigning to that change other than the order in which it occurs. It is meaningless to say they decay at a fast rate at first, and tapering off. That case is not in any way distinct from them decaying slowly at first, and quickly at the end.

I thought of an example of change without meaningful time: I have a universe with an unstable particle. It eventually decays. The time it takes to do that is meaningless.
— noAxioms

Talking about time in the sense of measurement there, if that's all you have in your universe, "the time it takes to decay" is simply whatever unit you apply to the change in question. — Terrapin Station

There can be no units. There is nothing on which said units could possibly be based.

So are you asking if someone (who?) performs associative acts in that situation?

There is no simulation. It is a universe with ordered events.

If you were using the wheel that goes around twice as fast as the change for time measurement, then it would mean twice as much time. — Terrapin Station

Then you're relating processes anywhere to that wheel, and not to time.

Okay. That makes sense but you're just pointing out that time is relative (in a different sense than the special relativity sense) to whatever we're using as the change for measurement. In other words, "In the same time"=you have to be referring to some set of changes that you're using for the relative measurement. For example, the changes in a clock. — Terrapin Station

Don't understand what you're saying. It doesn't need to be any particular amount of time for the one wheel to change twice as fast as the other. I chose rotation because rotation is absolute, not relative to anything. Sure, there are two wheels and thus there is a relation to them, but I didn't need to specify the relation with time (the RPM of either) to make my point.

I thought of an example of change without meaningful time: I have a universe with an unstable particle. It eventually decays. The time it takes to do that is meaningless.

I have a million such particles, and at some point, x% of them have decayed. Is there any meaning to a half-life of them? Is there meaning to the concept of half-life at all, as distinguishable from just a list of the order in which the million particles decay? The latter is just a numbered list. I don't see how 'time' has any effect on that where it is meaningful to assert that a lot of particles decay at first, but the last ones take much longer between decay events. Maybe the curve is the other way around and the final ones take place 'close together'. There would be no way to distinguish that model from another.

Two equal size wheels spinning, and one goes around twice as fast as the other. That seems to be twice the motion (change) in the same time. The one changes by 2 degrees while the other changes by 1 degree, and if change were equivalent to time, the one must take twice the time of the other to do that.

OK, but twice as much motion is not twice as much time.
It's like saying that momentum is kinetic energy. An object can't have one without the other, but it doesn't follow that they're ontologically the same thing.
'Change' is better than 'motion', the latter being just a subset of change. The paint on my house fades over time. That's change, but not motion. I can also have change without time: The air gets thinner with altitude: change over altitude vs change over time. Change seems not to be ontologically equivalent to time.

More consecutive funniness.

Time may require change to be meaningful, but change is not what it is.
— noAxioms

That's pretty close to what I've been trying to tell Terrapin, change requires time, but change is not what time is. — Metaphysician Undercover

I'm contrasting this with what Terrapin quotes immediately after:

I've already explained to you how time can pass or proceed without any change or motion. — Meta

So you loosely agree that time without change is not meaningful, but here you say time can pass without any change.

T-S, You seem to defend a definition of time as change, but complain about common language use, which I was not trying to do. I haven't read all your posts, but perhaps you could point to a post where you explain that if that's what you claim.

I said you cannot assert that a change has not taken place just because it cannot be measured. But you are asserting exactly that.
— noAxioms

I was not asserting that. — Metaphysician Undercover

Fair enough. You said physicists have determined that, and they don't claim that.

I've been saying that time is not change

With that I agree. "I changed my political viewpoint after the last election" "How much?" "By just over 2 hours"
Indeed, that makes no sense. Time may require change to be meaningful, but change is not what it is.

I think that you cannot truthfully state that a change has taken place unless that change has been measured. — Metaphysician Undercover

Another fallacious mistake. I said you cannot assert that a change has not taken place just because it cannot be measured. But you are asserting exactly that.

Imagine a very short period of time, Planck length or shorter. Physicists have determined that no physical change can occur in a shorter period of time. — Metaphysician Undercover

Sorry to jump in on this discussion, but you contradict yourself. Physicists have determined no such thing, especially since this would violate conservation laws.

Wikipedia:
"The Planck time is by many physicists considered to be the shortest possible measurable time interval; however, this is still a matter of debate." — Metaphysician Undercover

You quote the definition, which is about measurable interval, and yet above you claim that no change takes place in that interval. It simply does not follow that something doesn't exist (small change) just because it cannot be measured.

You are conflating "passage of time" (which is measured by clocks) with the wikipedia expression "objective flow of time" (which doesn't exist). — Inis

I have to agree with Luke on this one. 'Passage of time' implies flow to the average person, and I don't think the typical eternalist would ever use that term. I wouldn't. Clocks measure duration (length in the temporal dimension), and you seem to equate 'passage' with that, but I don't, and neither does most of the literature, as Luke has been pointing out.

How about we say that things interact with each other, but interacting things do not necessarily measure each other. — Metaphysician Undercover

Interaction implies two way relationship, so perhaps a 1-way interaction.

The moon is a poor example since we're in the gravitational field of the moon at all times and it is impossible for it not to be there, even if hidden behind a curtain. A specific state can be collapsed to us only after at least a second, but the moon in general cannot cease existence just by no longer looking at it, so to speak.

Measuring is a special activity of comparison which human beings with minds do.

You're describing a different dictionary definition of the word. A QM measurement is nothing of the sort, unless you ascribe to the Wigner interpretation I guess. I'd rather not limit myself to such a solipsistic interpretation of QM. Even Wigner himself bailed on support of his own interpretation for that reason.

Things which interact with each other are not necessarily gather information into one point. Do you know what it means to gather information? Or are you just making up a nonsense definition of that, to go along with your nonsense definition of measurement?

I don't think I used the term 'gather information' so far.

So the rock compares it's own state prior to its interaction with the photon to its own state posterior to its interaction with the photon? That requires a memory. The day you find a rock capable of doing that comparison, let me know.

You make comparison sound like a decision. I'm just saying that the rock is in a different state with the photon than it would be without (or with a different) photon. It doesn't make a comparison between those two states. Nothing can since any system has access to only one of the two states.
Rocks have great memory. Ask the geologists. But that is on a classic scale. From a QM standpoint, all matter has perfect memory, hence physics' conservation of information principle. There, now I've used the term 'information', but the physics definition, not the one you're using.

Anyway, I think we cannot communicate on this subject. You insist on the everyday language meaning of my words and not the physics ones.

Under presentism, there has to be a present hypersurface, and there has to be only one of them. Unless you pull the trick of denying objective reality etc. — Inis

Agree, but a hypersurface is 3D surface in a 4D space, and under presentism, there is no 4D space, only the 3D 'all of reality'. It isn't a hypersurface anymore if it is all of reality, no? That was my point, and perhaps it is just semantic.

It seems like you do not know what measurement is. — Metaphysician Undercover

Then choose another word to refer to what I'm describing, else we cannot communicate.

Measurement, by definition requires a comparison. The measurement devices in QM are calibrated to perform comparisons.

So when I open the box to check if the cat is dead or alive, what carefully calibrated device to I need to do this? It can be done in the total darkness if that helps.

The rock is doing a comparison of photon detected vs photon not detected. The state of the rock is different depending on this comparison.

This would be like saying that light hitting a rock is an act of measurement. — Metaphysician Undercover

I had mentioned the rock above. Yes, it very much is a measurement. Thing X (source of photon) has now caused an effect on said rock, and X now exists to the rock. That's how QM measurements work. It causes the state of X and the state of the rock to become entangled. The special equipment in labs is only special because it records the measurement precisely for the purpose of the knowledge of the lab guys, but measurement itself is trivial.

You can assert otherwise, but then we're just talking about different things. You asked me what it means for an extended object (not all in one point in space) to not be in a defined state at the present, and this is what I mean by that.

Of course measurement requires processing, it is a process. You cannot measure something without actually measuring it. — Metaphysician Undercover

We have different definitions of measurement. I'm speaking of measurement in the QM wave-function collapse sort of way. That interaction is 'actually measuring it'.

Measuring creates a knowing. If there is no knowing, then there has been no measuring.

Yes, I figured that was the definition under which you were working. I'm not talking about knowing.

Wouldn't you agree that the movements of my arms and legs ought to be understood as occurring in a different frame of reference from the movements occurring within the neurology of my brain, and my nervous system?

I don't see how any of that doesn't occur in all frames of reference. Maybe I don't understand how you're using the term. I'm interpreting it as 'inertial frame of reference' but maybe you mean POV or something, except no POV is specified then.

Why would this event, which measures all the defined states as one state, need to be in the future of those states? Can't the different defined states just be compared as occurring in different frames of reference? — Metaphysician Undercover

It takes time to gather all information about the spread-out state into one point (said future event) which can be anywhere, not necessarily an event that is part of me.

Choosing different frames of reference just defines a different set of events to be 'my state'. Under presentism, there is only the preferred frame, and other frames don't represent my actual state.

The light hitting your eyes is processed, and the image is created. — Metaphysician Undercover

Measurement doesn't require processing. The light hits me somewhere (eyes, toenail, whatever) and I've measured the moon. It exists to me now. The processing is only necessary for me to know it exists, but knowing doesn't define existence except under idealism where the photon never hit me at all.

What do you think it means for an entity not to exist all at one place? Could one part of that entity be in one frame of reference, and another part be in another? — Metaphysician Undercover

All (reasonably local, like not outside the Hubble Sphere) parts exist in all frames.
Being not all in one place means I am not in a defined state except to an event which has measured that entire state, which can only be in the future of the state being defined.

I wouldn't say that this is "right now", because the image is created, and that takes time. The light hitting your eyes is processed, and the image is created. So even the light from the moon hitting your eyes is in the past by the time you see the image. — Metaphysician Undercover

Quite true, but it is still at least 'right here', or at least as much as 'here' can be defined for an entity which doesn't exist all in one place.

Your present hypersurface is inaccessible to you. If you seek information about any of the simultaneous events that make up your present, you have to wait for the information to become part of your past light-cone. — Inis

Under presentism, there is no hypersurface or light cone, both 4 dimensional concepts. So if you seek information about any of the simultaneous events that make up your present, you have to wait for the information to come to you, at which time the information is no longer about the present.

Same thing, but my attempt to word it the presentist way. Walter Pound (the rarely seen OP) put it quite well in his post on the prior page.

But I still observe the objects in my present. — Echarmion

The observing is done in your present, but what is observed is only right here, nowhere else. I cannot see the present moon, but I see light in the image of moon right now. That light is right here, and from that image, I deduce a moon in the past and infer the moon still being there in the present, totally unmeasured. This process is automatic and not usually noticed. Andrew M points this out.

Either we are referring to an objective present, in which case all information I currently observe refers to an objective past, or we are referring to my subjective present, in which case I can observe objects in my present.

What you refer to is probably a proposed objective present. In that scenario, present reality is observer independent, and the present defines you, not the other way around. That present is not reference frame dependent, and thus reality is the same for everybody (as it should be for any observer-independent stance).
It is almost self contradictory since nothing you see is real. The moon you see cannot be real because you see a past version of it that cannot exist. I don't find that contradictory. You just cannot see anything real, but it is an observer-independent view, so it still exists just fine.

In an observer-defined reality, each observer observes a different point in the universe, and observes only that point, with other objects existing relative to that observation, and each observer defines a different reality, which can be a local state (presentism), or a light cone (eternalism) .
I am sort of in this observer-defined camp myself. I have a relational view of existence, sort of like idealism except it has nothing to do with people or consciousness, and things cause themselves to be real to me, or to the rock over there, whereas under idealism, my conscious observation I think causes those things to be real.

If this person is real, and independent of you and your present, relativity tells you that she also has her own present, which is as real to her as your present is to you. Your presents are not the same. Presentism is false. — Inis

Your present is not necessarily 'the present'. In fact, quite unlikely to be. Presentism is safe from this sort of argument in my opinion.

Aristotle demonstrated, that if you describe such changes in terms of states, you'll always need an intermediate state between the two states, to account for the change. — Metaphysician Undercover

Ditto with presentism, which also has states in between, else it is a series of discreet jumps.

Getting down to the quantum level, neither case is infinite regress. There comes a point where no measurements are taken and there are no intermediate states. This comes from me, who has thrown his lot in with the principle of locality rather than the principle of counterfactual definiteness. Can't have both....

Did you not see the quote I posted on the previous page of this discussion:

The resulting timeless cosmos is sometimes called a “block universe” — a static block of space-time in which any flow of time, or passage through it, must presumably be a mental construct or other illusion.

It seems quite clear to me. — Luke

Yes. That quote does not say there is no motion or no time. It just says time doesn't flow in that model.

I think that there is "no motion under eternalism" from everything I've read about it. It also states the same in the article I linked to in my previous post. Eternalism is synonymous with the block universe. — Luke

The article never says that there is no motion under anything. The word in fact never appears.

I am at the top of the stairs, and 2 seconds later, face down at the bottom. That's motion. The block has both those states, separated by 2 seconds.

In other words, with the current method, you can leave earth for a year to travel in time, and when you come back after a year for you has passed, on earth a year and one minute will have passed. — Tomseltje

Sounds to me like you traveled about a year into the future, just like we all do. Travel into the future seems effortless. It's not doing it that's the trick.

Anyway, the subject of the thread implies that one's interpretation of time has anything to do with the possibility of time travel. Assuming time travel is to the past, as is typically assumed, it is impossible, period. A-theory has nothing to do with that.
Such a concept would involve sending information to the past, and that has never been possible under any valid interpretation of physics.
Forward is easy, at least for things with reasonably limited information. Information travels that way no problem. High speed isn't required to do it.

All things change place as time passes, it's a premise of relativity. — Metaphysician Undercover

I know of two premises of SR (one of which predates the theory by several centuries), and a third for GR. None of them are "All things change place as time passes".

And that's not what your claiming, because taking a side trip around another tree is not measuring the distance between yourself and the tree. — Metaphysician Undercover

Exactly, just as the twin that takes a side trip to some other star and back is not measuring the duration between the two events of departure and return.

Indeterminate means without a fixed value. If the quantity of time measured between when the twins separated, to when they reunited, varies from one frame of reference to another, it is without a fixed value, and is therefore indeterminate. — Metaphysician Undercover

I can measure the distance between myself and that tree over there, and get an indeterminate value because one of the measuring tapes takes a path around that other tree to the left over there, and thus measures a different distance. So all measurements are indeterminate in that sense. But I could have calculated how each of those measurements would come out ahead of time. Those measurements are fixed before they are done, as opposed say to quantum measurements which are not predictable in advance.

I think you are wrong to say that the light cones are not frame dependent. Any event has a light cone. According to SR, the present of an event, or time that an event occurs, is frame dependent. Therefore the light cone for any event is frame dependent. — Metaphysician Undercover

Events are fixed (by definition), not frame dependent at all. They're points in spacetime, and don't have frame dependent qualities such as velocity, duration, or length and so on. Their light cones are determined by light speed, not the frames, so those are also fixed.