Does Time Cease to Exist Without Matter?

[minio]

Maybe stupid question, but if time is dependent on matter would there be time, if there are only photons? Or are they considered matter in this case?

 

[salvestrom]

No. The process is reversible, and energy is conserved. It is just an unlikely sequence events events given entropy.

My remark about additional energy was referring to the energy 'lost' when the cue strikes the ball producing a sound. In order to physically reverse the process that energy needs to be put back into the cue. While this is mathematically a reversible process, physically I know of no process that would allow it, anymore than the embers of a fire can regain the radiated heat. I consider these things beyond unlikely.

 

[gendou2]

If you want to measure the passage of time, you can use a clock.
So far as I know, a clock must be a physical entity made of matter.
If you assume no matter, there can be no clocks, so no way to measure the passage of time.

Maybe stupid question, but if time is dependent on matter would there be time, if there are only photons? Or are they considered matter in this case?

I cannot think of a way to make a clock out of photons alone.

On the other hand, the expansion of the universes reduces the temperature of the CMBR.
You might be able to get a rough measure of cosmological time this way.

 

[phinds]

If you want to measure the passage of time, you can use a clock.
So far as I know, a clock must be a physical entity made of matter.
If you assume no matter, there can be no clocks, so no way to measure the passage of time.

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Which is EXACTLY what I said in the original question that started this thread. What's your point? My question is NOT whether we can measure time under the stated condition but whether or not it exists if it can't be measured. In all practical terms, it's a useless question, but it's my question non-the-less.

 

[budrap]

I'm not exactly sure what you have in mind with that, but it seems to overly trivialize time.

The point is that time cannot be demonstrated to exist independent of the physical processes by which we claim to measure it and therefore the concept of time as an independent phenomenon doesn't have any scientific basis. This is not an attempt to trivialize time but to attribute to it only those characteristics that have an empirical foundation. Think of it as the Occam's Razor approach, minimizing extraneous assumptions

 

[budrap]

@budrap: Time is part of the way we measure the separation of events. Whether we use human inventions such as the second, or simply say 'it took awhile', these things relate to an actual property of the universe that exists regardless of how we describe it.

The assertion that time is "an actual property of the universe" as opposed to a property of material processes lacks, I believe, any empirical support and therefore isn't really scientifically substantive.

 

[phinds]

The point is that time cannot be demonstrated to exist independent of the physical processes by which we claim to measure it and therefore the concept of time as an independent phenomenon doesn't have any scientific basis. This is not an attempt to trivialize time but to attribute to it only those characteristics that have an empirical foundation. Think of it as the Occam's Razor approach, minimizing extraneous assumptions

I can't see it that way, somehow. It seems pretty much like you're saying there IS no such thing as time (I don't think that's what you are saying, but I don't know how else to describe my reaction). I like Dave's post #13, but it doesn't invalidate your point of view.

 

[DaveC426913]

My remark about additional energy was referring to the energy 'lost' when the cue strikes the ball producing a sound. In order to physically reverse the process that energy needs to be put back into the cue. While this is mathematically a reversible process, physically I know of no process that would allow it, anymore than the embers of a fire can regain the radiated heat. I consider these things beyond unlikely.

Precisely. That is what defines the direction of time. We do not see shards of glass leap together then back onto a shelf where they nudge a person's elbow.

The pool cue and break is analogous to the universe right now. Low entropy, clear direction of time.

The pool table after ten minutes is analogous to the universe trillions of years from now. Very high entropy, no direction of time.

I film the billiard table on a video camera for ten minutes. I play it back to you but only the last minute - and I don't tell you whether I play that minute forward or backward. Can you tell by looking at that minute which direction I played it? Nope.

(Note, by the way that it works whether or not you include friction. If you allow friction then, after 9 minutes all the balls are motionless - no direction of time. If the billiard table and balls are frictionless, then after 9 minutes they are still careening around completely randomly. Either way you have lost the arrow of time in the video I show you. The universe, being a closed system, conserves its energy, thus it is equivalent to the frictionless version of the pool table.)

The original point of comparing the universe to the billiards table was that, trillions of years in the future, there are no low-entropy objects such as pool cues or atmospheres. You just have a uniform soup of billiard balls all with random motion. They carom off each other but, since they're all just billiard balls bouncing around, there is no further increase in entropy, no increase in disorder. Thus the arrow of time is lost.

See?

 

[lukesfn]

.
The original point of comparing the universe to the billiards table was that, trillions of years in the future, there are no low-entropy objects such as pool cues or atmospheres. You just have a uniform soup of billiard balls all with random motion. They carom off each other but, since they're all just billiard balls bouncing around, there is no further increase in entropy, no increase in disorder. Thus the arrow of time is lost.

According to the Poincare Recurrence Theorem, the balls on the billard table will return to near to there starting position after a finite amount of time which can be estimated.

As I undertand, Entropy and the 2nd law of Thermodynamics are relative to an observer. I'm not sure if there can be an observer in a matterless universe, but I would assume events continue to occur separated by time weather observed or not because I personally assume that the moon still exists even if I am not looking at it.

I guess that weather or not time needs matter ends up a bit like asking if a tree falls in the forest and nobody is around to hear it, does it make a sound. I depends on how you define time for one thing.

 

[Ynaught?]

The assertion that time is "an actual property of the universe" as opposed to a property of material processes lacks, I believe, any empirical support and therefore isn't really scientifically substantive.

So do you believe the same goes for space?

 

[DaveC426913]

According to the Poincare Recurrence Theorem, the balls on the billard table will return to near to there starting position after a finite amount of time which can be estimated.

As I undertand, Entropy and the 2nd law of Thermodynamics are relative to an observer. I'm not sure if there can be an observer in a matterless universe, but I would assume events continue to occur separated by time weather observed or not because I personally assume that the moon still exists even if I am not looking at it.

I guess that weather or not time needs matter ends up a bit like asking if a tree falls in the forest and nobody is around to hear it, does it make a sound. I depends on how you define time for one thing.

Now that I think about the far, far future where the universe is just a lukewarm homogenous soup, I can begin to conceive of a universe where time is ambiguous. If nothing evolves from one state to another, then what does it mean to have time pass?

 

[salvestrom]

Now that I think about the far, far future where the universe is just a lukewarm homogenous soup, I can begin to conceive of a universe where time is ambiguous. If nothing evolves from one state to another, then what does it mean to have time pass?

This is the crux of it really. Many posters here argue time hasn't every really existed, but noone's been brave enough to try and explain the chronological separation of events. Others are suggesting that it exists currently, but won't in a future where nothings occurs and nothing can record it. Your post is something of a middle ground. It might exist, but is it really relevant?

Perhaps we can consider a separate space in a potential multiverse where beings have discovered how to peer across the void and watch other 'universes'. What is their take on the state of our far future? They can still record time via their own watches, but absolutely nothing will happen. I realize the thought leaves a loophole through which we can escape by saying 'well, as long as time passes somewhere...'.

We should also consider that recording the interval between two non-events is something we do everyday in the present and real world. Particularly when waiting for someone who is late.

In reference to your (dave's) response to the response to the billiard balls. I totally get where you are coming from, but I feel the reality is that there are some seriously complex interactions that we could watch happen and know if it were reversed. Your second point about the far future I also understand and gets right to the heart of the topic... which we seem no closer to resolving, as awesome as it is.

If you'll excuse me, I've decided to go tell Chalnoth quantum mechanics is wrong...

 

[Lord Crc]

This seems analogous to the big bang. Perhaps there was something before the big bang but if we can't measure any effects from it then it's irrelevant to us and we say that it doesn't exist.

It's my understanding that measuring "actual" time, which enables motion, requires an increase in entropy. If the universe is in a state where there is no way to increase the entropy further, then it will be impossible to measure time, and thus it might as well not exist.

Then again I'm just a layman so...

 

[lukesfn]

It's my understanding that measuring "actual" time, which enables motion, requires an increase in entropy. If the universe is in a state where there is no way to increase the entropy further, then it will be impossible to measure time, and thus it might as well not exist.

In the second law of thermodynamics, Entropy isn't required to increase, only forbidden to decrease. Also entropy can be calculated differently from different perspectives.

It is possible that the universe could have constant entropy and that we exist in a vacuum fluctuation but that wouldn't stop us from measuring time.

What the 2nd law really tells us is that is imposible to observe the passing of time perpetually, regardless of what the universe does, entropy will get you in the end. It's not possible to live for ever. So, perhaps it's accurate to say that time might as well not exist after you die.

 

[OCR]

recording the interval between two non-events

Would be a nifty trick, wouldn't it?...



OCR

 

[phinds]

This seems analogous to the big bang. Perhaps there was something before the big bang but if we can't measure any effects from it then it's irrelevant to us and we say that it doesn't exist.

It's my understanding that measuring "actual" time, which enables motion, requires an increase in entropy. If the universe is in a state where there is no way to increase the entropy further, then it will be impossible to measure time, and thus it might as well not exist.Then again I'm just a layman so...

The is at the heart of my question, which, after all this discussion I am beginning to see as more of a philosophical one than a physical one (I'm not happy about this). My question is not and never has been whether or not time can be measured (I agree it cannot) or whether or not it has any effective meaning (I agree it does not), in the far-future scenario. My question has been, and remains, does it EXIST --- does it in some physical sense continue to "flow" as it now is flowing. Turns out, as can be seen in this thread, that's not as simple a question as I had hoped and is apparently more philosophical than I would have preferred.

 

[Fuzzy Logic]

Saying that time ceases to exist is just a scientific cop-out. Just because it can't be perceived doesn't mean it doesn't exist. If it ceases to exist, then how does it renew? How did it begin in the first place? It just spontaneously came into existence? Rubbish! I can't think of anything in nature that is not ultimately cyclical.

Every time I think about questions such as this (the beginning or end of existence), it inevitably leads me to conclude that time and space are infinite.

 

[shifty88]

the flow of time is an illusion perceived by an observer to make sense of his or her conscious perception of change.
Time is not intrinsic to the universal laws of nature, rather it is intrinsic to the human psyche. It is simply a concept used in the human mind to explain the passage of one event to another.
It is a tool that we use to describe the motion of 'stuff' in the universe. Time does not exist.

 

[OCR]

My question has been, and remains, does it EXIST --- does it in some physical sense continue to "flow" as it now is flowing.

No, in the condition you describe in your first post, time does not exist.

At least, according to...

People before me believed that if all the matter in the universe were removed, only space and time would exist. My theory proves that space and time would disappear along with matter.

http://en.wikipedia.org/wiki/Hole_argument#Einstein.27s_resolution



OCR

 

[phinds]

Saying that time ceases to exist is just a scientific cop-out. Just because it can't be perceived doesn't mean it doesn't exist. If it ceases to exist, then how does it renew? How did it begin in the first place? It just spontaneously came into existence? Rubbish! I can't think of anything in nature that is not ultimately cyclical.

.

Although I tend to agree w/ you, one of the things I've found is that the universe doesn't give a flying <expletive deleted> what you or I think, and what you have posted is just personal speculation with no tie to any factual information.

 

[phinds]

the flow of time is an illusion perceived by an observer to make sense of his or her conscious perception of change.
Time is not intrinsic to the universal laws of nature, rather it is intrinsic to the human psyche. It is simply a concept used in the human mind to explain the passage of one event to another.
It is a tool that we use to describe the motion of 'stuff' in the universe. Time does not exist.

Interesting personal opinion but with no tie to any factual information not really helpful in resolving the question.

 

[phinds]

No, in the condition you describe in your first post, time does not exist.

At least, according to...



http://en.wikipedia.org/wiki/Hole_argument#Einstein.27s_resolution



OCR

Fabulous llink. Thank you.

I don't "get" it, but I did figure out some time back that Einstein was smarter when alive than I am now, so I tend to listen to him.

 

[phinds]

that time might as well not exist after you die.

Yes, but that's not relevant to the question at hand, in which I already posited that WHETHER it exists has no practical meaning but is the question anyway. My question is not whether it is "meaningful" or "practical" to say that it exists, but DOES it exist.

 

[Fuzzy Logic]

Although I tend to agree w/ you, one of the things I've found is that the universe doesn't give a flying <expletive deleted> what you or I think, and what you have posted is just personal speculation with no tie to any factual information.

Definitely. However, when there are two equally valid solutions to a problem, the simplest solution is always more correct. Show me where in nature anything ever spontaneously comes into existence and I will reconsider my perspective.

 

[OCR]

Thank you.

You're welcome,

Paul (OCR)

 

[phinds]

Definitely. However, when there are two equally valid solutions to a problem, the simplest solution is always more correct. Show me where in nature anything ever spontaneously comes into existence and I will reconsider my perspective.

You should read more on quantum mechanics. Stuff pops into existence CONSTANTLY at the quantum level, and at least one model says our entire universe started that way, so your point is totally at odds with current understanding of how things work. You are probably, like me, more comfortable in a Newtonian universe where that weird stuff doesn't happen, but whether we like it or not, it's what happens.

 

[Fuzzy Logic]

You should read more on quantum mechanics. Stuff pops into existence CONSTANTLY at the quantum level, and at least one model says our entire universe started that way, so your point is totally at odds with current understanding of how things work. You are probably, like me, more comfortable in a Newtonian universe where that weird stuff doesn't happen, but whether we like it or not, it's what happens.

Even in QM things don't just come into existence. Matter is energy. Energy is never created or destroyed. It is the essence of infinity.

Edit:
Now that I think about it, if we are being semantic, it actually addresses your original question. If matter didn't exist, then the universe is pure energy and time would still exist. In order for time not to exist there would have to be absolutely nothing and that conflicts with the law of energy conservation.

 

[phinds]

Even in QM things don't just come into existence. Matter is energy. Energy is never created or destroyed. It is the essence of infinity.

.

If I understand it correctly, your reading of QM is incorrect. Stuff DOES just pop into existence. Any QM-knowledgeable folks care to jump in here?

 

[shifty88]

Interesting personal opinion but with no tie to any factual information not really helpful in resolving the question.

I don't think you will find a satisfactory answer to your question. We don't understand time enough


I ask you this. If time is not a figment of the imagination(which i can accept), and also not a tool to measure motions caused by the expansion of space and other forces, or a higher dimension; then what is it.

If time ceases to have a meaning when heat death is reached it suggests to me that time is not a law of nature. Would gravity and electro-magnetism cease to exist also?


I don't know the credentials of the author to this link.
http://www.timephysics.com

 

[phinds]

If time ceases to have a meaning when heat death is reached it suggests to me that time is not a law of nature.

I agree, but that's just restating my question, which is "DOES it exist after heat death?" Not "does it have meaning" (it doesn't seem to in any practical sense), just does it exist.

Again, this is getting way more philosophical than I had hoped, but based on the intersting facts and opinions stated so far in this thread, that now seems inevatible.

 

[shifty88]

will this do.

No

:D

 

[Fuzzy Logic]

Heat death does not suggest zero energy, only that the energy is not usable.
The energy would be completely homogenous in the universe (as vacuum energy?).
Since energy has mass, I think this means that it would still affect gravity and you cannot have effects without time.

 

[phinds]

Heat death does not suggest zero energy, only that the energy is not usable.
The energy would be completely homogenous in the universe (as vacuum energy?).
Since energy has mass, I think this means that it would still affect gravity and you cannot have effects without time.

Yes, this is consistent with QM's statements that "quantum foam" / "quantum fluctuations" cause stuff to pop in and out of existence. If that keeps happening forever, then even the arrow of time will be preserved, because it's not likely that they will pop OUT of existence before poping INTO existence.

That doesn't answer my fundamental question, BUT ... I think it's a satisfactory answer in a practical sense and if QM is right, then my fundamental question is meaningless because there IS no condition under which nothing exists.

 

[Fuzzy Logic]

Hypothetically if nothing at all exists then like others have said, time and space have no meaning. How do you describe the dimensions of nothing?

 

[budrap]

The assertion that time is "an actual property of the universe" as opposed to a property of material processes lacks, I believe, any empirical support and therefore isn't really scientifically substantive.

So do you believe the same goes for space?

Yes, in this sense: Space is nothing more than our conceptual understanding of the behavioral interactions of matter and energy. Which is to say that there is no such thing as "space" that exists independently of the matter and energy properties by which we define it.