My understanding of time (and space):

That which at least one apparent intelligence has developed from itself, specifically for the use of itself.

But before you can conceive of a phase space, you have to conceive of a theory that gives rise to that phase space. The phase space is just a slice of the theory; you need to lay out the theory first. — SophistiCat

This is exactly what I was refuting in the quoted bit. I suspect maybe the word “phase” is leading you to this conclusion, because a phase implies a temporal process, which is why I also named the synonymous term “configuration space” which has no such connotations. You don’t need any notion of time or any specific theory incorporating time to have a notion of there being multiple possible ways a thing could be. A configuration space is just a map of those possibilities. That has use in theories of dynamics to plot phases of cyclical processes, but you don’t have to think of such a theory before you think of the more general tool of a configuration space.

This is exactly what I was refuting in the quoted bit. I suspect maybe the word “phase” is leading you to this conclusion, because a phase implies a temporal process, which is why I also named the synonymous term “configuration space” which has no such connotations. — Pfhorrest

I know what a phase space is. A phase space describes relationships between free variables in a particular theory. A different theory will give rise to a different phase space with a different basis, depending on its ontology.

One test I use for definitions is: Does the definition point unambiguously to the word being defined?

In your two definitions: "that diversity of existence whereby that which is existentially a subject is enabled to receive contrary determinations in existence" and "a certain general respect relative to different determinations of which states of things otherwise impossible may be realized." fail that test. I don't think that anyone presented with the definitions alone would think that they referred to 'time'.

As a mathematician, I often think of time as a variable that generates contours in the complex plane. If one views points in that plane as "events" then the contours represent "histories". No philosophical conundrums there. :cool:

An ant walks into a bar and says "hey, why are you all moving so slowly?"
But seriously, an ant would experience time faster relative to us. And a whale slower. As the speed at which time passes is relative to the creature experiencing it. And outside of living experience there is only the speed of light or the movements of the stars to go by. Time can pass faster in one place than another, depending on the gravity, but it seems the same in either location so who cares

I love any films that deal with the topic. — Benj96

Hmmm... let's put this to the test. Have you seen Primer (link: IMDb)?

Is it linear or cyclical?

Yes-ish maybe. It's curved; it can go in various directions, some of which reach ends. Oddly these ends might further extend in some cases indefinitely into other universes. It's quite interesting...

...see e.g. here and here (two blog posts in a series by Dr. Dilts);
...and/or, here (PBS Space Time, Youtube; there are also multiple prior episodes reviewing concept of Penrose diagrams and such).

As for closed time loops, I hear there's a Chronology Protection Agency that works to prevent this.

Discrete or continuous?

No idea.

Does it actually exist outside our conscious awareness of passing events?

The answers "yes" and "no" are both correct depending on what the question is really asking.

Are all "nows" the same?

The answers "no" and "mu" are both correct depending on what the question is really asking.

When is the end or beginning of an event?

Depends on the event; and depending on the event, there may not be a beginning or end to it.

Why does it seem to have a direction?

Because even with instruments postdiction is much easier than prediction. This is the same as the entropy answer others have given with a slight bent towards perspective.

What would we be able to know about the world if we had no concept of time?

To me this seems too speculative to have an answer.

Or if we had no standardised unit of time?

Either we would use obvious non-standard units or too speculative to have an answer.

What is the relationship between time, energy, rate and change?

There empirically appears to be a symmetry of change regarding fundamental processes; said symmetry allows the notion of "rate of change" to be meaningful as a metric of time. The symmetry is sufficiently strong that processes appear to evolve nearly identically with respect to shifts in time; time translation symmetry per Noether's Theorem allows us to derive a particular kind of value we call "energy" as a conserved quantity.

(BTW disclaimer: I am not a physicist... I just take interest)

“Billy Pilgrim has come unstuck in time.”

From Slaughterhouse 5 by Kurt Vonnegut

Dream on! — A Seagull

You dream of an instrumentalist utopia?

a superb demonstration of "later" — Benj96

Indeed. Perhaps you are beginning to understand. Of course, "later" is only one aspect.

One test I use for definitions is: Does the definition point unambiguously to the word being defined? — A Seagull

Time is information, the rate of which at any local point in space can be determined on a thermal spectrum from a state of solid stasis (absolute zero) to pure potential/potency (speed of light).

the rate of which at any local point in space can be determined on a thermal spectrum from a state of solid stasis (absolute zero) to pure potential/potency (speed of light). — Benj96

That still does not point to 'time'.

The future already exists, and the past exists in the future. The present obviously influences the future, but the past has a future as well. — neonspectraltoast

This sheds light on Einstein's " all time acts on all other time all of the time ". Thanks

Time is an illusion. It is a man made dimension to locate a point in an ever changing space.
We don't really have time we have change. The change only has one direction - the direction of change.
We say forward in time, but what we experience is really forward in change.

When a glass falls off the table it shatters into a hundred pieces - this change can not be reversed.
And so it is for all change. Yet you state the following:

The perception of past events has some component that reaches across time and space and can and does influence past events. The events themselves don't change, but you, in the present, always influenced them in the way that you did. — neonspectraltoast

I would be interested to know how you arrived at this?
Are you stating that all points in time / change are states of consciousness, and therefore remain malleable to consciousness?

the rate of which at any local point . . . — Benj96

The notion of "rate" requires "time". Circular argument. Sorry.

I left this forum forever.

Time is a parameter of physical processes. It is discrete and unidirectional. — Vladimir Krymchakov

What makes time discrete? In what sense? As in that it has a beginning and an end? If so how would you prove your reasoning? Especially if energy cannot be created nor destroyed - if that is the case then there is always interactions and exchange of information which requires time.

Or is it discrete in passage - as in the unitary second - because seconds are arbitrary artificial constructs which arent natural to the universe. They are discrete because we chose their length.

Or is it discrete in rate? Because as we know from relativity the rate at which time passes varies depending on the speed of an object. Time dilation and contraction occur so even the second -our discrete unit- changes depending on the strength of gravity or velocities.

Time may seem discrete because we are unable to measure time duration below the Planck scale.

Time may seem discrete because we are unable to measure time duration below the Planck scale. — jgill

Not to voice agreement or disagreement, but one of the difficulties of Planck scale is that it's a precise scale... it's hard to square that against Lorentz transforms. If there's something discrete about time, it seems it should also be related to something discrete about space. (Then, there's also singularity concerns, such as what this scale's meaning is at horizons).

Is a concern about whether time is discrete or continuous a truly substantive issue, or is it akin to other debatable subjects that have little relevance to the physical world, like the existence or non-existence of irrational numbers?

Is a concern about whether time is discrete or continuous a truly substantive issue, or is it akin to other debatable subjects that have little relevance to the physical world, like the existence or non-existence of irrational numbers? — jgill

It is TRUELY substantive, if you believe time exists. As, if there exists a planck length of time, then time is a procession of discreet points like the frames of a movie reel. It is not continuous.

This would mean anything that exists over time also exists as a procession of discreet points - including ourselves :)

It is TRUELY substantive, if you believe time exists — Pop

In what way is it substantive? Are there physical processes that go one way if time is discrete and another way if time is continuous? :chin:

I believe time is an illusion. But for those who believe it is a physical property of the universe, and who accept that a planck length of time exists, would accept that time is composed of individual planck lenghts. If you examined time fundamentally at the smallest scale you would find it is composed of individual planck lenghts strung together - like the frames of a movie reel.

This would mean we pop in and out of existance!

Maths is not my area, please correct me if I'm wrong.

I'm not sure that one can conclude that time is composed of individual Planck lengths strung together. My understanding is that measurements cannot be made at these lengths, so we don't know what goes on down there. Maybe continuity over a non-measurable interval, or discrete jumps. Who knows? :chin:

Fair enough. Thanks

In my view, “time” is defined as the form of any possible or actual change. Time & change are synonymous; which is precisely why whatever truth that’s regarded as being eternal, i.e., an eternal truth, is considered to be so, on the basis of its incapability of changing. For example, a logical one; such that the incapability of a thing to both be & not be what it is, is regarded as holding eternally so, exactly because its truth is considered as being incapable of changing.

Time to me is frequency seen inside-out and from a distance. Consider a universe containing a single, unchanging, rigid, simple ball. What is time? There is no change, no objective measure, no frame of reference we could justify over another...

Now replace the ball with an oscillator, such as a hydrogen atom. We could take a single period T of the oscillation as a unit of time. During one period of oscillation, the configuration of the atom changes, but it always returns to the same configuration after T. There is again no sense of change from one period to the next: this universe is a cyclic one, but at least there is some time.

Adding a second oscillator with the same period, or a factor of the first one's period, adds nothing. But what if we add a new oscillator with a period pi * the first oscillator's period? We can now count the tickings of the first oscillator with respect to the configuration of the second, and vice versa. The configuration of each oscillator is still cyclic, but the configuration of the system of the two will never repeat itself.

With such a system, I can make you a clock. Unfortunately, we don't exist, it's just two oscillators, but it's the thought that counts.

Time = counting rhythmic beats on an internationally-accepted scale.

Time is one of the four dimensions of spacetime.