The infinite regress occurs only with infinite time; if there is a start of time there is no infinite regress. If time is circular, there is no infinite regress. It's only the 'time goes back forever' model that is a problem. — Devans99

So not actually presentism but presentism without a start. I'd agree that would require time that extends backwards infinitely by definition. I wouldn't agree that either option disallows presentism. And further, saying either has a problem doesn't address the experiential issue I'm bringing up. Not to mention that the experiential issue I'm bringing up is all that presentism is when we get rid of unjustifiable metaphysics, after all.

Given that this is a thread about time it might be useful to reflect on the proven fact that time runs at different speeds, depending on the relationship between the observer and large masses such as planets. As example, GPS satellites have to take the time speed shift between their location and the surface of the Earth in to account or their location data would be worthless.

This time speed difference has never mattered at human scale because the difference in time speed between the top of a mountain and sea level is measured in billionths of a second. Thus, we assume that time flows at a fixed speed, an illusion generated by a very limited perspective.

The point here is that when it comes to all issues concerning time, the most likely answer may be the we have no idea what we're talking about.

The point here is that when it comes to all issues concerning time, the most likely answer may be the we have no idea what we're talking about. — Jake

Why couldn't we simply focus on what we're referring to in "practical," observable, experiential, phenomenal terms? What would be the motivation to posit time being anything different than that?

So not actually presentism but presentism without a start. — Terrapin Station

I don't think presentism and a start of time are compatible. What would come before and cause the start of time? There is nothing to do that, so it seems an impossible combination.

And as I believe the evidence points to a start of time, that seems to rule out presentism.

The point here is that when it comes to all issues concerning time, the most likely answer may be the we have no idea what we're talking about. — Jake

I agree. Hence we must continue to probe this fascinating mystery.

I don't think presentism and a start of time are compatible. What would come before and cause the start of time? There is nothing to do that, so it seems an impossible combination. — Devans99

So first, by definition, nothing comes before it. Re causing it, apparently you buy the old "something can't come from nothing" bumper sticker slogan, but that slogan is actually unsupportable. It's just an arbitrary fiat, precipitated by the counterintuitiveness of it.

And as I believe the evidence points to a start of time — Devans99

What evidence?

Aside from that, you didn't address this: "Not to mention that the experiential issue I'm bringing up is all that presentism is when we get rid of unjustifiable metaphysics, after all."

Re causing it, apparently you buy the old "something can't come from nothing" bumper sticker slogan, but that slogan is actually unsupportable — Terrapin Station

But something coming from nothing, including no time? Sounds unbelievable to me.

What evidence? — Terrapin Station

There is a strong argument for a start of time here:

https://thephilosophyforum.com/discussion/5302/an-argument-for-eternalism/p1

There is also the Big Bang theory which has time running slower and slower as we get closer to the Big Bang till the point of the singularity when it is unknown what happens to time. It is suggestive of a start of time.

Also the BGV Theorem states in brief that an expanding (on average) universe cannot have a timeline infinite into the past; it must have a beginning.

But something coming from nothing, including no time? Sounds unbelievable to me. — Devans99

Hence "precipitated by the counterintuitiveness of it," but the world isn't actually required to conform to what's intuitive to us.

There is a strong argument for a start of time here:

https://thephilosophyforum.com/discussion/5302/an-argument-for-eternalism/p1 — Devans99

I had a laundry list of objections to that in that thread.

Re the other two things, constructing things with mathematical conventions doesn't actually work as evidence.

Hence "precipitated by the counterintuitiveness of it," but the world isn't actually required to conform to what's intuitive to us. — Terrapin Station

But the world appears to follow logical (if not intuitive) rules; hence all the progress in science has been possible. I see no reason why the start of time should disobey basic logic... what you call 'counterintuitiveness' is actually contrary to logic IMO (and the world is logical).

I had a laundry list of objections to that in that thread.

Re the other two things, constructing things with mathematical conventions doesn't actually work as evidence. — Terrapin Station

IMO I addressed your objections. What is mathematical about an expanding universe needing a start point? It makes perfect sense just as a logical argument. And we know from experiments that time slows in the presence of gravity; so time starting at the Big Bang (=maximum gravity) is not unbelievable,

But the world appears to follow logical (if not intuitive) rules; hence all the progress in science has been possible. I see no reason why the start of time should disobey basic logic... what you call 'counterintuitiveness' is actually contrary to logic IMO (and the world is logical). — Devans99

I have no idea what you'd think logic is if you think this has anything to do with logic. At any rate, logic, ontologically, is a way of thinking about relations.

What is mathematical about an expanding universe needing a start point? It makes perfect sense just as a logical argument. And we know from experiments that time slows in the presence of gravity; so time starting at the Big Bang (=maximum gravity) is not unbelievable, — Devans99

For example, the big bang involving "maximum gravity" is really about us playing with mathematics. It's a consequence of our mathematical constructions.

Why couldn't we simply focus on what we're referring to in "practical," observable, experiential, phenomenal terms? What would be the motivation to posit time being anything different than that? — Terrapin Station

Well, science has done that, and proven that time runs at different speeds in different circumstances.

This information is not particularly practical at human scale, but as we expand the scale (such as is illustrated by GPS satellites) it becomes more of an issue.

When the conversation focuses on universal issues, such as the nature of now, it's not possible anymore to assume the realm of time is fixed as we've long assumed from our perspective at human scale.

It's kind of like the impression we had that the Earth was flat and at the center of the universe. From human scale at the surface of the Earth this seems a reasonable and practical notion. As we gain more perspective, a different picture emerges.

The point is that insofar as we're focusing on what we're referring to in practical, observable, experiential, phenomenal terms, it doesn't follow that (the most likely answer may be that) we have no idea what we're talking about.

The point is that insofar as we're focusing on what we're referring to in practical, observable, experiential, phenomenal terms, it doesn't follow that (the most likely answer may be that) we have no idea what we're talking about. — Terrapin Station

Did you know that time runs at different speeds in different circumstances? Do most forum members know that? Do most citizens know that?

If you answered no to any of these questions, there's your proof that we don't know what we're talking about.

The fact that time runs at different speeds is unlikely to be the last mystery about time to be revealed.

I have no idea what you'd think logic is if you think this has anything to do with logic. At any rate, logic, ontologically, is a way of thinking about relations. — Terrapin Station

Logic involves information; truth values are either 1 or 0 in the case of boolean logic or somewhere in-between for fuzzy logic. The truth values from logic correspond to information. The universe is composed of information. So the universe is logical.

For example, the big bang involving "maximum gravity" is really about us playing with mathematics. It's a consequence of our mathematical constructions — Terrapin Station

How else can we interpret the fact that the red shift of galaxies increases with their distance from us if it is not that they were once very close together?

Did you know that time runs at different speeds in different circumstances? Do most forum members know that? Do most citizens know that?

If you answered no to any of these questions, there's your proof that we don't know what we're talking about. — Jake

You were using "we" to refer to "some individuals but not us collectively"? In other words, a way to say "you peons contra me and the other in-crowd people like me"?

Did you know you were a Hegelian?

Kant had argued that metaphysics is impossible, that it is impossible for the human mind to achieve theoretical knowledge about all of reality. Hegel on the other hand, set forth the general proposition that "what is rational is real and what is real is rational" and from this concluded that everything that is, is knowable. Since there can be nothing unknowable, the idealists were confident that they could know the inner secrets of absolute reality.

https://www.coursehero.com/file/17475102/Chapter16/

No wonder we are not on the same page, it is a very different conception of both logic and reality.

Did you know you were a Hegelian? — unenlightened

I guess so. A universe where 2+2!=4 is a universe with no information in it:

A. 2+2=5
B. Implies 0=1
C. Implies True=False
D. Implies no information

A universe without information would be a very boring place. So I'd argue for any substantive universe, basic logic and basic maths must hold.

Plus I don't think I bother with philosophy too much if metaphysics is impossible; thats my favourite part.

Presentism (believe that only now exists) is the opposite view of eternalism (belief that past, present and future are real). — Devans99

Not necessarily. Consider the anti-realist's interpretation of time:

Definition: "Now" is a tenseless designator that refers only to actually occurring sensory input (including thoughts and memories).

Premise: The meaning of "physical time" is reducible to sensory input translated according to the linguistic conventions of physics.

Conclusion: Physical time is tenseless.

Well, science has done that, and proven that time runs at different speeds in different circumstances. — Jake

Please cite. It's clocks that run at different rates - "clock" understood very broadly. I'd like to view the proof that time runs at different rates.

Consider the anti-realist's interpretation of time — sime

But even an anti-realist must have an opinion on whether sensory input data from the past/future actually exists in the same sense as 'nows' sensory input data?

Presentism (believe that only now exists) is the opposite view of eternalism (belief that past, present and future are real).

Presentism posits 'only now always existed' so all forms of it require an infinite regress, which is not only undesirable, its actually impossible:

1. The number of events in an infinite regress is greater than any number.
2. Which is a contradiction; can’t be a number and greater than any number*.

Eternalism does not require an infinite regress; we have a prime mover who is beyond time (and thus beyond cause and effect) who creates time and the universe. It’s the simplest logical model. — Devans99

Gotta read all the other replies...but your OP seems to be a back door entry to a supposed "proof of 'God'." (Don't have the time right at the moment.)

As I see it...this very instant is ALL that exists.

Yesterday certainly does not "exist"...and the second before right now no longer "exists."

Tomorrow does not exist...and an hour from now does not exist.

The only thing that actually exists is the present moment...and then it ceases to exist and another "present moment" takes its place.

Thats many people's gut instinct on time, 'only now exists'. My point is time is unintuitive and you actually have to work through the logic to see that 'only now exists' is not viable. For example, your gut instinct on time would not have told you that it runs slower in the presence of gravity, but it does. Not intuitive.

'Only now exists' leads to 'only now always existed' which leads to an infinite regress; IE its can't happen; more than only now must exist.

time would not have told you that it runs slower in the presence of gravity, — Devans99

Clocks. Please cite research that shows time runs slower.

https://en.wikipedia.org/wiki/Gravitational_time_dilation

But even an anti-realist must have an opinion on whether sensory input data from the past/future actually exists in the same sense as 'nows' sensory input data? — Devans99

From a meaning-as-use perspective, the difference between a past-referring image - such as a photograph of a deceased historical figure, versus a presently-referring image - such as a live-streamed web-cam image, is how those images are used, which is to say that the images activate very different inferences in the mind or behaviour of an observer.

Presumably a realist concerning the past will insist that the difference between these sets of inferences are of a different underlying type in being representative of an underlying commonsensical ontological distinction between past , present and future that transcends an observer's use of the images.

The anti-realist concerning the past will refrain from drawing this ontological distinction, for example because he might understand all inferences as being ultimately present or future referring. For instance, the anti-realist might argue that the very concept of an evidence-based account of history refers to the future possibility of making certain empirically verifiable discoveries by historians and scientists.

At the very least, if commonsense realism concerning temporal semantics is rejected, past present and future in the psychological sense becomes a mixed up place.

Thank you. I can see how you can be confused. Given, however, your insistence on your ideas as against reality and fact, I despair of your getting this right. Time - if you read your own reference - doesn't "run," doesn't pass, doesn't do any of those things. What happens is that observers observe that clocks that measure subjective time, run at different rates depending on differences in relative velocity, or gravity. None of this is simple, and care in expression and even thinking about relativity is required. As you say, it's non-intuitive.

When you look at your clock and the clock of a friend (say) who was travelling relative to you, you can say - and people do say - that time passed more slowly for him than for you. And in a restricted sense, this makes sense. Your clock, even with your body as clock, measured time as passing at a different rate from your friend. He really did age less; you more. But this has to do with measurement, not with the thing measured. The thing measured is an interval in space-time. And that, analogously with distance in three-space, is, in the lingo, invariant. Research space-time interval. Learn the difference between perceived/measured time, and how that is not the same as time itself as it is in space-time. One is subjective and relative - fair enough. The other isn't.

Thats many people's gut instinct on time, 'only now exists'. My point is time is unintuitive and you actually have to work through the logic to see that 'only now exists' is not viable. For example, your gut instinct on time would not have told you that it runs slower in the presence of gravity, but it does. Not intuitive.

'Only now exists' leads to 'only now always existed' which leads to an infinite regress; IE its can't happen; more than only now must exist. — Devans99

The "time runs slower in the presence of gravity" is an unusual statement. I've never been in a place without gravity. I don't think any human has...nor ever will. Gravity is everywhere. The planet Jupiter, far away as it is, exerts gravity that impacts on planet Earth. The gravity of our nearest star neighbors impact on Sol (and all of us)...and the gravity of the Andromeda Galaxy impacts on our galaxy. So I'm not sure where you are going with that.

In any case, you are dealing with questions about the true nature of the REALITY of existence...an area of interest that has perplexed the most intelligent humans who ever lived on our planet. And you are supposing you can, via what you term as "logic"...eliminate a vast area of speculation about that true nature...despite the fact that most of them have not been able to do so.

I acknowledge that I do not KNOW the true nature of the REALITY of existence...and I cannot think of a way to pare it down as easily as you seem to think you have done. There are no things I can say MUST be for existence to be explained...and none that I can say CANNOT BE in order for existence to be explained.

it is POSSIBLE that "now is all that exists...despite what you suppose. (I am not saying "now" is all that exists...I am merely saying it MAY BE all that exists...and I do agree that, intuitively, that seems more likely to me than that it CANNOT POSSIBLY exist.

Do you not concede that there are imponderable that MAY make what you see as cut-and-dry "logic" that dictates as invalid?

I've given thoughts about this myself

Or think of it this way. Each event in an infinite regress has a predecessor so each event makes sense on its own, but the series as a whole has no start so the series as a whole can't exist logically. — Devans99

If we assume an eternal universe we are assuming that there exists an unlimited amount of time before now. I don't see a logical contradiction in the idea of "no start to a series" when we grant an unlimited amount of time before now. If we agree that 1 day ago is possible and that any day before some day is possible is also possible then all finite amount of days before now are possible.

Typically any attempt I've seen against an eternal universe goes along the line of presuming an infinite number of something exists then asserting infinite is impossible without actually pointing out a logical contradiction giving the assumption they already made.

The definition of the first transfinite number is the cardinality of the set of natural numbers. No way is that a number. It's a conception of a mad man.

I should point out that there is only one kind of infinity; by definition it is the largest thing, so it's not possible to have two of the largest things; one of them would not be infinity. If you want to take a look at what sort of nonsense the opposite assumption produces, then bijection is the term to google. You will find that the procedure produces plainly laughable results such as the set of natural numbers being the same size as the set of rational numbers (the 2nd is clearly infinitely larger than the first).

What are we to make of the rules for working with transfinite cardinals:

∞+1=∞.

If you buy the first point about a single type of infinity, then the above expression immediately leads to 1=0. Even if you don't, there is something deeply wrong with it. In english, it's saying that 'there exists something, that when you change it, it does not change'. What sort of object behaves like that? No objects behalf like that, so does it deserve to be enshrined at the heart of a supposedly logical discipline (maths)? — Devans99

Infinity means without limit that doesn't exist as a value in conventional math. It's not part of a set of natural numbers therefore not appropriate to treat it as a number in conventional math like "∞+1=∞". The reason why the number of elements in the set of natural numbers "equals" that of rational numbers is because they defined "equals" when it comes to cardinality to mean possible to completely map from one to the other. In that case it's possible to map all natural numbers to all rational numbers without missing any rational numbers.

Every whole number maps to every fraction like this:

The "time runs slower in the presence of gravity" is an unusual statement. — Frank Apisa

The more intense the gravity the slower times runs I should of said.

Do you not concede that there are imponderable that MAY make what you see as cut-and-dry "logic" that dictates as invalid? — Frank Apisa

There are probably questions we can't answer (maybe 'why is there something rather than nothing?). But where we are presented with a logical absurdity (presentism), we can draw appropriate conclusions; that is just part of the scientific method.

If we assume an eternal universe we are assuming that there exists an unlimited amount of time before now. I don't see a logical contradiction in the idea of "no start to a series" when we grant an unlimited amount of time before now — coolguy8472

But I would argue that it does not matter how much time you allow; if the objects do not have temporal starts, they do not exist. To see what I mean, try imagining a brick without any identifiable spacial start point. It would not exist. Works exactly the same for time as it does for space. As I've pointed out before (https://thephilosophyforum.com/discussion/5242/infinite-being), infinite existence is impossible for beings so it should be impossible for anything else also.

Infinity means without limit that doesn't exist as a value in conventional math. It's not part of a set of natural numbers therefore not appropriate to treat it as a number in conventional math like "∞+1=∞". — coolguy8472

You are saying you can't perform mathematical operations on infinity? IE it's not a number.

Every whole number maps to every fraction like this: — coolguy8472

The point is that the rationals are larger than the naturals. For every natural, there is an infinity of rationals. That's a simple proof that bijection gives the wrong answers.

Please cite. It's clocks that run at different rates - "clock" understood very broadly. I'd like to view the proof that time runs at different rates. — tim wood

Google is your friend. I learned this from a science documentary on either Netflix or Amazon, sorry I don't remember which, or the name of the show.

"Do you not concede that there are imponderable that MAY make what you see as cut-and-dry "logic" that dictates as invalid? — Frank Apisa


There are probably questions we can't answer (maybe 'why is there something rather than nothing?). But where we are presented with a logical absurdity (presentism), we can draw appropriate conclusions; that is just part of the scientific method. — Devans99

Okay...apparently you will not concede that there can be anything wrong with your assertion that "presentism is logically absurd" and therefore eternalism is "the way things are."

I do NOT KNOW which prevails...nor do I know that the question must resolve into "presentism", "eternalism" or any of the other variational theories regarding time/space...and their impact on the true nature of the REALITY of existence.

It can be interesting discussing different guesses about which seems more likely, although I doubt any of us will get much further than guessing on the question.

Since you seem so sure of your position, though, I'd like to ask you if you see any significant implications of it on the "human condition." If you are correct, as you seem certain you are...are there significant other truths that derive from it?