Is time in essence - constant?

[trickae]

http://en.allexperts.com/q/Physics-1358/Time-Expanding.htm]Is[/PLAIN] time expanding in some way analogous to the expansion of space? If we talk about the expansion of space "accelerating," doesn't that imply that time is a fixed scale against which the rate of spatial expansion can be measured?

i was pondering this for a couple of hours now randomly searching the web. Do you think that a constant time is a convenience to us - however it isn't constant in the grand scheme of things?

 

[CraigD]

Time is not constant. Only the speed of light is constant in a vaccumm. The acceleration in this case is the acceleration in our frame of reference. If we changed frames we would change the rate of acceleration that we observe.

Another point here is that the time isn't changing, but the distance is actualy changing. That is space is expanding causing the acceleration.

CraigD, AMInstP
www.cymek.com

 

[DeepGround]

Time is constant at the speed of light.

Someone explain to me how light can travel in anything other then a vacuum when it is soooo small that it travels between the elementary particles where everything is vacuum.

When light travels through water it is still traveling at full speed it just takes longer to get from one end to the other because it does not take a direct route as it is bouncing all over the place.

 

[StatusX]

Expansion is a process, which means it happens over time. So it makes no sense to talk about the expansion of time, or spacetime. What we mean when we say space is expanding is that the shape of spacetime is such that as you move in a timelike direction, distances between inertial observers in a spacelike direction get larger.

You can visualize this as something like a sphere: as you move north or south the lines of longitude get closer or further apart. If you think of time as the north/south direction, so that space is a 1D circle, then people in this spacetime would observe the universe expand, reach a maximum radius, and then contract.

 

[CraigD]

Time is constant at the speed of light.

That may not be the best way to state that.

Someone explain to me how light can travel in anything other then a vacuum when it is soooo small that it travels between the elementary particles where everything is vacuum.

When light travels through water it is still traveling at full speed it just takes longer to get from one end to the other because it does not take a direct route as it is bouncing all over the place.

You are correct, on this. What I meant when I said in a vacuum is traveling in a straight line without external forces acting on it.

CraigD, AMInstP
www.cymek.com

 

[yogi]

In de Sitter's universe, time and space are modeled as a sphere - expasion of the sphere dilates both time and space. In Einstein's universe, time and space are modeled as cylindrical

 

[Fluke]

Time is not constant. Only the speed of light is constant in a vaccumm. The acceleration in this case is the acceleration in our frame of reference. If we changed frames we would change the rate of acceleration that we observe.

Another point here is that the time isn't changing, but the distance is actualy changing. That is space is expanding causing the acceleration.

CraigD, AMInstP
www.cymek.com

Hello,

I happened to come across these forums when I was searching just on this subject matter.
I am not a PHD, or a Doctor, or even have a degree in Physics, my interest is merely entertainment as I happen to learn that I am quite good at conceptual Physics theory.

To address Craig's response:

You say Time is not constant, yet time is measured based on the speed of light reaching the Earth as a point of reference. That being said, it leads me to my next question just to kind of stir up imagination and start a discussion about it.

If time is not constant, do you believe time travel to the past is possible?

 

[Fluke]

In de Sitter's universe, time and space are modeled as a sphere - expasion of the sphere dilates both time and space. In Einstein's universe, time and space are modeled as cylindrical

On this note, expansion of the universe technically would not dilate time, if time is constant. It is my belief time is constant, which in this case means there is no relevance how the universe is model'd or who was correct or not. If time is constant it can not be dilated.

My particular interest is in Conceptual Relativity Theory. Just something I like to investigate from time to time out of sheer interest.

I personally believe time is constant. Mathematically I can't prove it, but, logically I can... If you care to discuss it further in detail.

 

[edpell]

...You say Time is not constant...

I would say:
1) time is constant in each observers inertia frame
2) time and place are not orthogonal in any inertia frame except your own

Backward time travel no.
Forward time travel yes - just move fast then wait awhile then stop moving - of course it all depends on which frame you are thinking in terms of

 

[Fluke]

I would say:
1) time is constant in each observers inertia frame
2) time and place are not orthogonal in any inertia frame except your own

Backward time travel no.
Forward time travel yes - just move fast then wait awhile then stop moving - of course it all depends on which frame you are thinking in terms of

Top bold is exactly why I believe time is constant. But to expand on that idea... If traveling back is not possible, then how is traveling forward based on #1?

Think of it in terms of solving a linear one step algebra equation: Where A = B

If A = the past and B = the future the = sign is the present.

What you are saying is: I can not change A, but I can change B. What would happen if you do?

Basic principle states: What you do to 1 side of the equation you have to do to the other.

A = B

i.e. 3x + 1 = 4 If we solve for X we have to manipulate A and B equally. If we do not balance out time and space, they will annihilate each other. To the point = (present day) and the past (A) no longer exsist. This is also the basic idea behind paradox theory. Ever watch the movie Back to the Future? It is filled with Paradoxial situations that never get resolved or to relate it to this discussion (The equation isn't balanced). I find that movie entertaining to watch from this standpoint.

I believe you can not time travel to the past, or the future, because time is constant and time is relevant in all orthogonal inertia frames or all non orthogonal inertia frames. So on this point I agree. But, time and space can be orthogonal and the principal remains the same.

 

[Fluke]

Sorry, to clarify more about the linear equation analogy:

100 years in the past someone invents a time machine and comes to our present day to talk to you and me. This results in the annihilation of the present and futures. We would not be talking about this right now.

Someone today builds a time machine and talks to the person who invented it 100 years ago. The present day as we knew it and the future have just been destroyed. We would not be talking about this right now.

Where as someone 100 years into the future invents a time machine and comes back to the present day to talk to you and me. He has just destroyed the present and future. Our present day no longer exists as we have made a tangent in space time the moment this person arrives. He destroys his past: which you and I are talking about right now. But he also destroys our future since he never left to our present day yet.

This is due to the balance that must be maintained. I believe if the balance between time and space are not maintained it would destroy the universe. Quite literally, the universe as I perceive it would blink out of existence.

 

[edpell]

100 years in the past someone invents a time machine and comes to our present day to talk to you and me. This results in the annihilation of the present and futures. We would not be talking about this right now.

If 100 years ago someone got in their spaceship and accelerated to a $$\gamma$$ of 100. In that state they wait one year on their local clock and then decelerate arriving here and now to talk with you and me. No problem. All is fine.

 

[Fluke]

If 100 years ago someone got in their spaceship and accelerated to a $$\gamma$$ of 100. In that state they wait one year on their local clock and then decelerate arriving here and now to talk with you and me. No problem. All is fine.

To make sure I understand what you are saying.

We accelerate an object that object would cease to exsist in the present, because it went into the future?

The concept of absolute space emphasizes dissimilarity between acceleration and deceleration. On absolute space, acceleration and deceleration are completely opposite actions for any relative observer. Hence, opposite effects of acceleration and deceleration on matter (relative mass increase or decrease) is concrete for any relative observers.

This point has been ignored in special relativity, which cause the twins paradox.


That being said, I leave you with this word problem:

Points A, B, C and D. Distance between Point A - B is equal to the distance between Point A and C. The distance from point A and D is equal to the distance between AB or AC respectively. Person 1, 2, and 3 are all the exact same age.

Person 1 travels at 1/2 speed of light from Point A to B and it takes him 10 years to make the journey. Person 2 travels at the speed of light from Point A to C and it takes him 5 years to make the journey. Person 3 travels at 1.5 x Speed of Light, from Point A to Point D and it takes him 2.5 years to make the journey. If Person 2 waits 5 years before leaving from the time Person 1 leaves and Person 3 waits 7.5 years before leaving at the time Person 1 leaves:

Who arrives at their destination first?
Which person is older?
Which person time travels?

 

[trogan]

Time is just a concept. It has no physical reality. There is only the present. No past or future. These are just concepts also. The universe as a whole changes state over time and it is this rate of change that is construed as time. Is this rate of change constant over the universe ? I doubt it. It is likely that as an object speeds up its rate of change (and therefore its experience of time) slows down.

 

[edpell]

It is likely that as an object speeds up its rate of change (and therefore its experience of time) slows down.

We have to be careful with the phrase "its experience of time". If you mean they do not age as much as we in the still frame do then yes. If you mean they in their frame see themselves as moving slowly no. If you mean they in their frame see us in the original frame as moving slowly no.

 

[Fluke]

We have to be careful with the phrase "its experience of time". If you mean they do not age as much as we in the still frame do then yes. If you mean they in their frame see themselves as moving slowly no. If you mean they in their frame see us in the original frame as moving slowly no.

I believe, time is constant, and only moves in a linear direction at the same rate from any relative perspective. Take my word problem as an example:

Points A, B, C and D. Distance between Point A - B is equal to the distance between Point A and C. The distance from point A and D is equal to the distance between AB or AC respectively. Person 1, 2, and 3 are all the exact same age.

Person 1 travels at 1/2 speed of light from Point A to B and it takes him 10 years to make the journey. Person 2 travels at the speed of light from Point A to C and it takes him 5 years to make the journey. Person 3 travels at 1.5 x Speed of Light, from Point A to Point D and it takes him 2.5 years to make the journey. If Person 2 waits 5 years before leaving from the time Person 1 leaves and Person 3 waits 7.5 years before leaving at the time Person 1 leaves:

Who arrives at their destination first?
Which person is older?
Which person time travels?

The answer to the questions:

They arrive at the same time.
Neither person is older. They remain the same age.
Neither person travels in time forwards or backwards.

What makes the bold statement true given my example for why it's not true?

 

[Al68]

I believe, time is constant, and only moves in a linear direction at the same rate from any relative perspective. Take my word problem as an example:

Points A, B, C and D. Distance between Point A - B is equal to the distance between Point A and C. The distance from point A and D is equal to the distance between AB or AC respectively. Person 1, 2, and 3 are all the exact same age.

Person 1 travels at 1/2 speed of light from Point A to B and it takes him 10 years to make the journey. Person 2 travels at the speed of light from Point A to C and it takes him 5 years to make the journey. Person 3 travels at 1.5 x Speed of Light, from Point A to Point D and it takes him 2.5 years to make the journey. If Person 2 waits 5 years before leaving from the time Person 1 leaves and Person 3 waits 7.5 years before leaving at the time Person 1 leaves:

Who arrives at their destination first?
Which person is older?
Which person time travels?

The answer to the questions:

They arrive at the same time.
Neither person is older. They remain the same age.
Neither person travels in time forwards or backwards.

What makes the bold statement true given my example for why it's not true?

In SR, your example simply can't happen, because a spaceship can't travel faster than light.

But of course in SR it's very possible to travel forward in time. In fact it's been measured in various experiments to considerable accuracy.

Do you think physicists just decided they liked the idea that time wasn't constant? No, they hated the idea, but it was forced on them against their will by reality. It's no exaggeration to say the scientific community was shocked and bewildered by the unrelenting observations and experimental results showing that time wasn't the constant they had all religiously assumed it was.

It seems to me that there are only three choices to deal with this:

1. Find contrary empirical evidence.
2. Show an internal logical flaw in SR.
3. Accept that time is not a constant.

Many physicists and others have tried 1 and 2 repeatedly over the last hundred years, and all their efforts only reinforced 3.

That being said, attempts at 1 and 2 are still valuable to science, and the first step in either of them is to thoroughly understand SR.

 

[Fluke]

Maybe to simplify the example:

You and I stand in front of each other. I say to you, "Time is constant." You say to me, "Time is not constant."

To prove our points... You walk in a circle the diameter of 36 inches at the speed of light for 1 minute and then stop to compare the time on our watches.

Now, From my perspective you disappeared for 1 minute. From your perspective I just stood there motionless for 1 minute. You stop moving and we compare the times on our watches.

Your watch is 1 minute ahead of mine.

Which of us is older?

Taking into account all perspectives. You disappeared for 1 minute. But from your perspective I was motionless for 1 minute. We age at the same rate relative to time being constant.

The ONLY way to prove the answer is to violate the Pauli Exclusion Principle. Which loosely translated means, "No 2 piece of matter can occupy the same intertial frame at the same time" else there is no possible way to derive a conclusion that time is not constant. It was confirmed testing Fermion particles in a simultaneous quantum state, and proven not possible. You or I would have to exsist in both interial frames at the same time in order to confirm that time is not constant, or that it is constant, and this is just not possible.

Did time not travel in a linear direction? That direction being: Forward, and at a constant rate to all relative perspectives?

Does that make you 1 minute younger than me?

Point is, time travels at a constant rate "Foward" it can not be stopped, reversed, or accelerated in any linear direction when all relative perspectives are taken into account.

 

[Fluke]

In SR, your example simply can't happen, because a spaceship can't travel faster than light. - I never said it was possible and that wasn't the question. I simply stated a hypothetical situation which is how theories are formed via Hypothesis.

But of course in SR it's very possible to travel forward in time. In fact it's been measured in various experiments to considerable accuracy.

Twins paradox is not a measurement of time travel. It's a measurement of relativity based around Gravity Quantum Mechanics.

Do you think physicists just decided they liked the idea that time wasn't constant? No, they hated the idea, but it was forced on them against their will by reality. It's no exaggeration to say the scientific community was shocked and bewildered by the unrelenting observations and experimental results showing that time wasn't the constant they had all religiously assumed it was.

It seems to me that there are only three choices to deal with this:

1. Find contrary empirical evidence.
2. Show an internal logical flaw in SR.
3. Accept that time is not a constant.

Many physicists and others have tried 1 and 2 repeatedly over the last hundred years, and all their efforts only reinforced 3.

That being said, attempts at 1 and 2 are still valuable to science, and the first step in either of them is to thoroughly understand SR.

Because they tried to create a reality that they had no means to create. Just like my example: I have no means to create the experiment, but why should that stop anyone from believing the world was round before they could prove it?

 

[Fluke]

In SR, your example simply can't happen, because a spaceship can't travel faster than light.

So what you are saying here is: Einstein's Theory of Relativity is wrong?

He stated, "When traveling close to the speed of light time slows down, when traveling at the speed of light, time stops, and when traveling faster than the speed of light time travels in reverse."

Well if it's not possible to travel faster than the speed of light, how can one assume time goes in reverse at any point what-so-ever relative to the speed of light?

Question: Why do we have to accelerate matter to time travel? If time travel is possible and people believe it's possible, why do we have to accelerate matter to, at, and beyond the speed of light to accomplish time travel?

 

[Al68]

To prove our points... You walk in a circle the diameter of 36 inches at the speed of light for 1 minute and then stop to compare the time on our watches.

I'll assume you mean less than the speed of light, since that is all that's possible.

Now, From my perspective you disappeared for 1 minute. From your perspective I just stood there motionless for 1 minute.

No, from your perspective you disappeared for 1 minute. From my perspective you stood there motionless while I was gone < 1 minute.

Which of us is older?

You are.

Like I said in my last post, this experiment has been performed many times.

 

[Al68]

So what you are saying here is: Einstein's Theory of Relativity is wrong?

Nope. Just the opposite. That theory says that a spaceship cannot travel at the speed of light.

He stated, "When traveling close to the speed of light time slows down, when traveling at the speed of light, time stops, and when traveling faster than the speed of light time travels in reverse."

Yes, and only massless particles (photons) scan travel at the speed of light, and no particle traveling faster can slow down to the speed of light. No such particle has ever been detected.

Well if it's not possible to travel faster than the speed of light, how can one assume time goes in reverse at any point what-so-ever relative to the speed of light?

Who assumed anything remotely resembling that?

Question: Why do we have to accelerate matter to time travel? If time travel is possible and people believe it's possible, why do we have to accelerate matter to, at, and beyond the speed of light to accomplish time travel?

Huh? Again, who is talking about exceeding or reaching the speed of light, or traveling backward in time?

I was referring to traveling forward in time at different rates by traveling at less than the speed of light.

Seriously, I would do a little more reading on the subject.

 

[Al68]

Because they tried to create a reality that they had no means to create. Just like my example: I have no means to create the experiment, but why should that stop anyone from believing the world was round before they could prove it?

They didn't create the reality, it already exists. Objects and people already travel at speeds below the speed of light. And that is all that is needed for an experiment to show that time isn't a constant. And the experiment has been performed many times.

 

[Fluke]

Originally Posted by Fluke
So what you are saying here is: Einstein's Theory of Relativity is wrong?

Nope. Just the opposite. That theory says that a spaceship cannot travel at the speed of light. - No the theory does NOT say a "spaceship" it says, there is nothing that can travel faster than the speed of light (That we can detect), it does not say specifically any 1 form of matter over another. It's already common knowledge photons travel at the speed of light. So just because we can't see beyond the speed of light it makes traveling faster than the speed of light impossible... If I were to agree with this, then that also means time travel is impossible into the future or into the past. And if we both agree on this point, it means I agree with you that Einstein is wrong... well to be fair, he wasn't wrong just inaccurate in his theory conjecture.

He stated, "When traveling close to the speed of light time slows down, when traveling at the speed of light, time stops, and when traveling faster than the speed of light time travels in reverse."

Yes, and only massless particles (photons) scan travel at the speed of light, and no particle traveling faster can slow down to the speed of light. No such particle has ever been detected. - Believe it or not, I am well aware of this, but it does not answer the question.

Well if it's not possible to travel faster than the speed of light, how can one assume time goes in reverse at any point what-so-ever relative to the speed of light?

Who assumed anything remotely resembling that? - You did when you said traveling faster than the speed of light is impossible. Well I repeat my question, if it is impossible how is it possible to travel in time, forward or backwards?

Question: Why do we have to accelerate matter to time travel? If time travel is possible and people believe it's possible, why do we have to accelerate matter to, at, and beyond the speed of light to accomplish time travel?

Huh? Again, who is talking about exceeding or reaching the speed of light, or traveling backward in time? - Which of my questions was misunderstood? Talk to anyone about time travel and everyone says 1 common thing. Accelerate matter fast enough it's possible. Why?

I was referring to traveling forward in time at different rates by traveling at less than the speed of light. - This is not conclusive enough to be considered fact, when nothing can travel faster than the speed of light "that we can detect." And, we have no means to test it to be true.

Seriously, I would do a little more reading on the subject.

Please try to keep personal opinions out, I already stated, I'm not a PHD, or have a degree, but I can argue logically and deny any proof you can show me as being factual based on our limited ability to test such advanced theories. Ultimately, time travel is impossible, Time is constant, and I have yet to talk to anyone, with a PHD whom can show factual evidence to the contrary. I've even talked to Physics professors at universities whom can not answer the questions I have posed to you and others on this forum.

 

[Fluke]

Believe me, I want an answer... Which is why I ocassionally try to engage in discussions about it... I want to know if I'm right or wrong, and haven't talked to anyone who can show me conclusive evidence that my... I hesitate to say, theories are incorrect or not considering 1 factor over another.

My idea, is looking from outside the box looking in and considering all possibilities, but the common accepted theory regarding this issue is inside the box looking out as there are no other possibilities which I disagree with.

 

[Al68]

So just because we can't see beyond the speed of light it makes traveling faster than the speed of light impossible... If I were to agree with this, then that also means time travel is impossible into the future or into the past. And if we both agree on this point, it means I agree with you that Einstein is wrong...

I didn't say that at all, what Einstein claimed was that if faster than light speed were possible, then backwards time travel would be possible. At sub-light speeds, only forward time travel is possible.

Well if it's not possible to travel faster than the speed of light, how can one assume time goes in reverse at any point what-so-ever relative to the speed of light?

Who assumed anything remotely resembling that?

- You did when you said traveling faster than the speed of light is impossible.

How is "faster than light is impossible" equal to "assume time goes in reverse"? Is English your native language?

Well I repeat my question, if it is impossible how is it possible to travel in time, forward or backwards?

Then I will repeat my response: Forward time travel is the result of relative speeds below the speed of light, not above the speed of light.

Question: Why do we have to accelerate matter to time travel? If time travel is possible and people believe it's possible, why do we have to accelerate matter to, at, and beyond the speed of light to accomplish time travel?

We don't. See above.

I was referring to traveling forward in time at different rates by traveling at less than the speed of light. - This is not conclusive enough to be considered fact, when nothing can travel faster than the speed of light "that we can detect." And, we have no means to test it to be true.

We have no means to travel at less than the speed of light? Seriously? We do, and we have tested this repeatedly. But in the (<light speed) experiments performed, only the rate that time passes is variable, not the direction (always forward).

Believe me, I want an answer...

Your responses to my previous posts indicate that you didn't read them. If that pattern changes, I would be happy to answer any further questions.

 

[Fluke]

I suppose I should let dead dogs lie.

You obviously don't comprehend the contradictions in your statements much less understand what I have said, and consistantly contradict yourself even disecting my posts without understanding them first.

If this ever changes let me know I would be happy to discuss it further.




The sky is blue! - That's not what I said, I said it appeared blue.

I humbly apologize for my lack in analyzing situations logically. I appear to not have that skill mastered as you do.

 

[Al68]

I suppose I should let dead dogs lie.

You obviously don't comprehend the contradictions in your statements much less understand what I have said, and consistantly contradict yourself even disecting my posts without understanding them first.

If this ever changes let me know I would be happy to discuss it further.




The sky is blue! - That's not what I said, I said it appeared blue.

I humbly apologize for my lack in analyzing situations logically. I appear to not have that skill mastered as you do.

LOL. There are many very knowledgeable people that usually respond to any question posed here about SR, but they aren't participating in this discussion. Obviously they are very much smarter than I am.

Good luck to you.

 

[Zula110100100]

Points A, B, C and D. Distance between Point A - B is equal to the distance between Point A and C. The distance from point A and D is equal to the distance between AB or AC respectively. Person 1, 2, and 3 are all the exact same age.

Person 1 travels at 1/2 speed of light from Point A to B and it takes him 10 years to make the journey. Person 2 travels at the speed of light from Point A to C and it takes him 5 years to make the journey. Person 3 travels at 1.5 x Speed of Light, from Point A to Point D and it takes him 2.5 years to make the journey. If Person 2 waits 5 years before leaving from the time Person 1 leaves and Person 3 waits 7.5 years before leaving at the time Person 1 leaves:

Who arrives at their destination first?
Which person is older?
Which person time travels?

Even with speeds of below light speed this answer cannot be solved I don't think because of not enough information to try to figure the relative time differences you would need to know all of the relative velocities and to determine that from the information given we would still need to know the directions of each points since if you drew a circle around A intersecting all the points B,C and D and B was only a few degrees away from C it would make the relative velocities much slower than if B were 180 degrees from C.

P.S. Sorry to some for bringing this thread back to the top of the page

 

[edpell]

In frame A both parties start. B travels in frame B which has a gamma of 10. B leaves in the year 2010 and arrives in the year 2020 slowing down and returning to frame A. Both A and B arrive at the year 2020 so in one sense we can say time is constant. A aged 10 years in frame A. B aged 1 year in frame B. When B returns to frame A they still carry only one year of aging. In one sense we could say time is not constant. The problem is the English language is based on Newtonian time. English does not contain the words for this back and forth between frames discussion.