What is time?

[watcher]

well i guess asking the substance spacetime is made of is too much ti ask even for me. so let's start with rade definition instead ...

 

IMO even consciousness is subject to time, for it can not exist without it.

 

first as an opinion, can you justify as why consciousness should co-exists with time or even be subject to it?

 

But I like what Rade had to say several posts ago.

 

Quote:by Rade

time is that which is intermediate between two moments, space is that which is intermediate between two existents. Thus space-time is that which is intermediate between two moments of existents.

Although it seems circular from the first glance--i.e. because spacetime is a collection of moments and existents, then all moments and existents are spacetime--there is more to it. I wish we could expand it from there.

 

okay let us expand with this. so time is what in between two moments.

so we need to understand what constituent a moment in order to understand time. because if one moment can be infinitely divisible, we might never find an instant of moment plus another instant of moment so we can derived an exact time between them, in other words, rade's definition make sense only as an approximation.

 

so if we are going to start this, we must first understand what a moment is, how does one can define a moment so that this moment can be a useful reference point to measure time? any idea?

[lawcat]

I would begin from the premise that: spacetime is that which is between two point-moments (points in space, each with moment of time). But, if we take that a moment and a point can not be real, but are merely infinitesimal periods, then our definition is false because it does not include what is inside of the period of the moment or the point, but only that which is between the two periods. So the definition can only be theoretically true if we accept the concept of moment (frozen time, a region of no expectation of future and totally completed past) and a point (a region of no volume, area, and length).

 

Then, if the definition is true theoretically, then we can look at how this point-moment operates, how it affects neighboring point-moments (is there codependence or hysterisis), how it affects matters which passes through it (in respect to velocity, density, etc.), and other relations in spacetime.

[Michael Mooney]

Watcher:

so if we are going to start this, we must first understand what a moment is, how does one can define a moment so that this moment can be a useful reference point to measure time? any idea?

 

A "moment" is just the mental *concept* of a "timeless instant," but there is no 'freeze-frame' timeless instant in the constantly moving universe (all "events" on all scales, always in motion.)

 

What about my post to Little Bang above (#678) do you and Lawcat not understand?

Michael

[watcher]

I would begin from the premise that: spacetime is that which is between two point-moments (points in space, each with moment of time). But, if we take that a moment and a point can not be real, but are merely infinitesimal periods, then our definition is false because it does not include what is inside of the period of the moment or the point, but only that which is between the two periods. So the definition can only be theoretically true if we accept the concept of moment (frozen time, a region of no expectation of future and totally completed past) and a point (a region of no volume, area, and length).

 

Then, if the definition is true theoretically, then we can look at how this point-moment operates, how it affects neighboring point-moments (is there codependence or hysterisis), how it affects matters which passes through it (in respect to velocity, density, etc.), and other relations in spacetime.

 

first. if we take spacetime as points in space with instants of time. we will fall prey under zeno's puzzling paradox of motion. he claimed like that a point particle occupying an equal amount of space cannot move in any given instant of time. because at any given instant of time the point particle is always at rest. do you understand the problem?

[watcher]

Watcher:A "moment" is just the mental *concept* of a "timeless instant,"

i said earlier that what we called time is the representation of motion.

 

but there is no 'freeze-frame' timeless instant in the constantly moving universe (all "events" on all scales, always in motion.)

actually. if the true state of matter is discrete as quantum theory implies, then everything in our universe are freeze frame timeless instants. in this scenario, even motion is an illusion.

imagine a pc monitor with no moving parts that can generate motions in its screen or a series of neon lights blink on and off to make it appear that lights moves, or hand waves of rows of people in a stadium. in all cases, something just go on/off, up/down or appear and disappear, and the apparent motion has nothing to do with it.

 

What about my post to Little Bang above (#678) do you and Lawcat not understand? Michael

 

yes i do. but that must be known experientially

[Michael Mooney]

Watcher:

actually. if the true state of matter is discrete as quantum theory implies, then everything in our universe are freeze frame timeless instants. in this scenario, even motion is an illusion.

 

You can't be serious! Do you actually deny the perpetual motion of all things on all levels in the universe?

So how small do you slice "time" to get a "freeze frame moment", by what instrument and how is the focus (the "frozen event") determined?

Then how does the viewer advance to the "next frame" in this cosmic "movie?"

 

Finally, you didn't address my post #678 at all.

Michael

[Rade]

....Rade, if you agree that you cannot perceive by touch ... ....the past....

Well, I do not so agree. Each time you touch your arm you perceive the "past", for your dead outer skin cells in the "present" exist as a "past fulfillment" of what was a "future potential" of being alive. Have you ever touched the ashes of a dead relative ? If you hold that the ashes represent the "past" of that loved one as human, then, if you touch them, you "perceive the past".

 

Edit: OK, let me give another example of what I am thinking here. Suppose a fish that you catch from ocean at time A. If you touch the fish at time A it is 100% in the present, for you have no past memory of touching it. Suppose at time B you put fish in alcohol, then at some time C you take fish from alcohol and touch it again. Now, I would hold there are two aspects to touching the fish at time C: (1) you touch fish at present preserved condition at time C and (2) you touch fish preserved as it was in a past moment (at time B) when it was placed into alcohol, that is, time stopped for fish at Time B. Thus, in this way, I hold it is possible to touch the past, while at the same moment of time, touch the present. I'm open to discussion to hear alternative views.

[Rade]

On Moments:

 

I see there is some interest in my definition of space-time, and that some would like to discuss the concept of "moments" and how they may relate to "time". I have some thoughts I will present for discussion. First, here is the definition of space-time I presented:

 

Time is that which is intermediate between two moments, space is that which is intermediate between two existents. Thus space-time is that which is intermediate between two moments of existents.

 

1. Moments are not existents.

 

2. Moments are an attribute of time, but separate. Existents are an attribute of space.

 

3. Time is not made up of moments, Time is that which is intermediate between moments. Space is not made up of existents, space is that which is intermediate between existents, therefore:

 

4. There is no time or motion within the 'moment', there is no space within the 'existent'.

 

4. Consider Moments A & B and Time C. Moment A is the begin of Time C and Moment B is the end of Time C. Therefore,

 

6. Moments always connect two times, moments do not connect moments. Example, Moments A, B, C connect Times X, Y in this way:

(to infinity).....A<----X----->B<----Y----->C.....(to infinity)

 

7. Because time is infinite, and moments are attributes of time, one moment (A) is always being taken away after another (B) and another ©....(to infinity).

 

8. The moment as an attribute of time is an identity....likewise, the existent as an attribute of space is an identity. Thus, "moments of existents" connect "space-times".

 

9. In the same way moments are always being taken away within time, existents are always being taken away from points in space, since both are born of motion.

 

I'll stop here to see if there are any comments.

[watcher]

No matter how you reify "time" and slice it up into "moments" or whatever, the "is"-ness of the present is ongoing, always "now." The "future" is the concept/word for *not* yet *now*, the present. The "past" is the concept/word for not still now, the present.

The "present" is the concept/word for now, which *is* all there *is*, ever, always.

 

to say that now is all there is , does not necessarily mean there is no time,

if now is all there is , then it must be all inclusive, including time.

in this scheme, now is the generator of time.

 

future is the well of potential,

now is the moment of actualization and closely related with consciousness.

and all objects of perception is in the past, fading away from the now.

 

can you wrap your mind around that?... seriously!

Naturally, there *is* always a delay between the origins of specific "signals" we call sensations/perceptions and what is being experienced.

But "signal delay" is a big can o worms re both "time" and relativity in general.

Michael

 

yes signal delay is controversial in relativity, but wait till you hear what QM has to say about it.

[watcher]

You can't be serious! Do you actually deny the perpetual motion of all things on all levels in the universe?

 

if motion is random and no cause, would that constitute as a perpetual motion?

 

So how small do you slice "time" to get a "freeze frame moment", by what instrument and how is the focus (the "frozen event") determined?

Then how does the viewer advance to the "next frame" in this cosmic "movie?"

 

the freeze moment is always achieved when there is a synchronicity of the electrons of what seen and the electrons in your eye. so using a camera lens shutter in the rate of light speed, you'll pretty see the whole universe is a freeze frame.

[CraigD]

A traveller taking off with a clock and a measuring tape takes off after having synchronized his timepiece with his friend. He goes flying at relativistic speeds around the sun a few times, and does very careful measurements of the inside of his spaceship, and the ticking of his clock. His buddy on Earth does exactly the same in his absence. In all the time he's away, the inside of his spaceship measures exactly the same according to his measuring tape. It changes not with an inch. His clock ticks away, at a perfect one second per second. He does not measure any change in the flow of time nor the length of a centimeter. Same with his buddy on Earth. Now, once he gets back on Earth, there's a problem. His clock is out of whack with his buddy's clock. How did this happen?

I *think* it happened because the different *forces of acceleration* on the traveler's clock slowed it down, while his buddy's clock did not have those forces acting on it. (Just in case you missed my countless repetitions of the above.)

I understand your thinking, Michael.

...

Moderation note: The rest of this post and 13 following it have been moved to the physics and math thread 20793, because they’re a discussion of the theory of relativity, which, while pertinent to the ontological question “what is time?”, is a distinct enough subject to warrant its own thread.

[Michael Mooney]

Sometimes it is challenging to find the precisely correct thread for a specific post. This is a spin-off from the other (relativity focused) "time" thread.

 

A thought experiment for "Ontology 101...What Is Time?":

 

If there were no clocks, what would "time" be?

What entity/medium/aether/whatever would "dilate" if there were no clocks "keeping time" differently?

 

Michael

[Little Bang]

If the Universe started with the BB then time must have started at the instant of the BB. In order to describe time I would think it helpful to know of what the BB was composed, Was it an explosion of some multi-dimensional system of virtual particles that somehow condensed into matter? Maybe it was quarks and all the weird particles that the standard model proposes. Or maybe it was just radiation with a wavelength short enough to equal the energy of the Universe. If it was virtual particles I can't see anyway that could help us understand time because they only exist in some neither world of which we don't have access to any information. If it was particles with mass that would suggest that gravity existed at the instant of the BB and would have prevented any expansion. On other hand, if it was an explosion of radiation then time would be a function of the wavelength of that radiation. If we assume that to be true then we must explain why time sped up as the Universe expanded. I can see only one way for that to happen. The wavelength of light from a source must not be fixed but must lengthen by something like 10^-36 meters/meter from the source.

[Michael Mooney]

Little Bang:

If the Universe started with the BB then time must have started at the instant of the BB.

LB,

Do you know what "the ontology of time" means as expressed in the question, "What is Time?"

 

There will be no need to address the rest of your post if you simply start off assuming... and continue to insist... that "time must have started at the instant of the BB."

 

See... the question "What is time?" needs an answer before continuing the conversation, assuming "it's" beginning and continuing existence as expressed in your opening statement.

 

If the cosmos is perpetually oscillating, as I see it, then there is no "beginning of time" as "when" the cosmos first came into existence (presumably "out of nothingness," just like in "creationism.")

 

If the above is true then "time" is just human reckoning of arbitrary Earth-commensurate units of measure between any and all arbitrarily selected "now points'... which are just metaphorical starts and stops on the Great Stopwatch in our minds.

Nuff for now.

Do you get my meaning?

Michael

PS to all: The essence of my ontological challenge to those who reify time is expressed as succinctly as I can in post 692 above.

Please don't let this last post derail reply to that essential (to me) thought experiment.

[watcher]

If there were no clocks, what would "time" be?

 

if there were no measuring rulers/rods, what would space be?

inches, meters are measures of space and in turn time expressed in seconds, minutes are the measure of motion.

 

if we can get past this simple definition of time, then we can move on to the onltology question... " what moves then?"

 

What entity/medium/aether/whatever would "dilate" if there were no clocks "keeping time" differently? Michael

 

quantum waves perhaps.

[freeztar]

I agree with all of the above, Michael, with one big caveat.

 

If humans did not exist, or any form of consciousness for that matter, time would still "pass". From an objective standpoint, the subjectivity of the observer is non-important.

 

Relativity is important though. It has been tried and found true. The Theory of Special Relativity shows us that velocity affects time and the Theory of General Relativity shows us that gravity affects time. Einstein et al. gave us the best tools ever created for understanding time. He was able to synthesize notions put forward by great minds like Schrodinger, Lorentz, and Planck. I don't think we're nearly done with our exploration of this question, but we at least know a little bit about how the beast behaves. ;)

[watcher]

If humans did not exist, or any form of consciousness for that matter, time would still "pass". From an objective standpoint, the subjectivity of the observer is non-important.

 

the observer is important to make sense of time. both in relativity and QM.

the world imagined to be a purely objective one are both trashed by einstein and the founders of QM.

 

do you have a full understanding of all forms of consciousness to conclude that time is totally independent of consciousness ?