What is time?

[StevenO]

Your missing the point, their is no such thing as "Time". What we call time dilation is purely mechanical. Just like the Thought Experiment, if you have two clocks, and you move one, then the light beam has to trace out a longer path, thus the clock dilates.
And here is a form of time travel, if you are 1 light year away from star A, you are peering one year into the stars history, but another observer 200 Light years away, is looking at star A; he is seeing 200 years into the stars past.
It all depends on your spatial reference frame.

Time has historically been closely related with space, the two together comprising spacetime in Einstein's special relativity and general relativity. According to these theories, the concept of time depends on the spatial reference frame of the observer, and the human perception as well as the measurement by instruments such as clocks are different for observers in relative motion. The past is the set of events that can send light signals to the observer, the future is the set of events to which the observer can send light signals.

http://en.wikipedia.org/wiki/Time#Spacetime

I did not deny time dilation. I just stated that it is the Doppler effect and that the Lorentz derivations are incorrect.

[Peron]

Well, I misunderstood.

[mcalevy]

You folks certainly have beat this issue to death.

Time exists only as a perception of the senses, and until the brain/mind transduces an external vibration into something that has meaning to an existing frame of reference that we already hold, it has no meaning. Thus our physiology limits what we can perceive time to be. We can perceive only certain frequencies. We live in a much different world of sound than a dog. We see a limited spectrum of light, not what an insect can see.

We can process about 30 frames a second of photon stimulation. If we had senses that could process twice that speed our perception of time would be much different. We have a brain that makes stuff up. Note the blind spot we all have in our retina where the optic nerve is attached. The mind fills in that blind spot so that we don't ever notice it. What else is the mind filling in? I can interrogate someone for about 10 minutes to find their frames of reference and have a really good idea of what their reality looks like on subjects we have not mentioned.

We are all making up this physical reality as we go along, and my reality has nothing to do with your definition of reality. If we decide to agree, we really at some level are in disagreement, because unless we perceive from exactly the same location, the information/vibration we perceive will be different. Perspective is so important to perception, like the difference that is experienced by a person sitting on the train looking out the window and a person that is sitting on top of the engine. At the end of the trip, they have had radically different experiences of a common journey. That is why each human is different. If we knew we were going to live for a thousand years, that would drastically affect our concept of time, because at some point we would realize how much information we were going to forget in our lifetime, and what we thought was important would radically change.

If you want to understand how treacherous the senses are, ask a sibling about something you both witnessed more than ten years ago. It will seem like they were on another planet at the time.

Time is whatever you decide it to be. So you might as well make up something good that works for you. Because in the end, nobody is going to agree with you.

We can agree to agree about a concept in an attempt to communicate, but what you will agree on will be totally irrelevant to someone who has never seen a clock or flipped an electric light switch.

[simple simon]

You folks certainly have beat this issue to death.

Time exists only as a perception of the senses, ...

Good post, and I think I might agree with both those statements, but, although all "reality" exists only as a perception of the senses, we are also able to logically deduce what time (and reality) may/must/should be. And although those deductions may be based on our sense perceptions, they can extend beyond them.

Cogito ergo sum is the only provable statement. And then only to yourself.

I enjoy these speculations on the nature of time and some of them are very thought provoking indeed. But personally I have yet to see (or hear, or feel) any clear reason why I should not trust that the version of reality given to us (or me, anyway) by our senses is as "true" an approximation of reality that this physical form can give us. Our interpretation is a different thing.

[StevenJay]

[...] personally I have yet to see (or hear, or feel) any clear reason why I should not trust that the version of reality given to us (or me, anyway) by our senses is as "true" an approximation of reality that this physical form can give us.

Heh - and therein lies the rub! Due to their inherent nature, all of our five "physical" senses can be manipulated by various means (chemical, electrical, even hypnosis). They can be distorted/altered, elliminated, or triggered artificially. Which begs the question: How can we ever be sure that we actually perceive what we think we perceive? Put another way, how can we ever be certain that this physicality we appear to inhabit is any more than a thought - an idea?

I recall reading a "channeled" statement years ago (don't recall who said it, though) that really spoke to me on a deep level: "Understand that, since you ARE the Universe, ideas aren't things that you have. Ideas are what you are."

A visual analogy I like to use involves a print by M.C. Escher:

In this view, we see "reality" as we've become accustomed to seeing it.


But as we begin to "back up" and consider this "reality" in a larger context, seemingly irreconcilable contradictions begin to appear. . .


and it isn't until we back up even more to a perspective outside of the frame, or "box," as it were, that we realize we've been observing (experiencing) an illusion.

[StevenO]

I recall reading a "channeled" statement years ago (don't recall who said it, though) that really spoke to me on a deep level: "Understand that, since you ARE the Universe, ideas aren't things that you have. Ideas are what you are."

I'm totally with you StevenJay. We cannot see how we are connected to the whole Universe, at a good moment we might just sense and feel it like a spirit passing through our souls.

In fact on bad days I sometimes have the feeling that what we perceive as the universe and consciousness is just our Sun desperately finding a solution for its own imbalance that we perceive as mortality. I also have the feeling that life is not a straight path from A to B, but a universal regression on all levels.

[junglelord]

I love Escher, I have two of his works on laminate.

[Nevyn]

While I agree and disagree with many statements made in this thread, I would like to attempt to see where the idea of time comes from. This probably should be a thread of its own but let's see where it leads us first.

In the EU, the most likely place for life to find itself is inside the plasma sheath of a brown dwarf. In this location, the stars energy is uniformly distributed onto the planet and there is no cycle of seasons (and may not be movement of the parent star relative to the planet but am not sure of that, I am continuing with this assumption though).

If there are no cycles to see, would a society in this location have a concept of time?

They would have a concept of change, a concept of movement, but would these equate to a concept of time? And if so, would it relate to our concept of time?

If we go even further and imagine the beginning of the universe, and I mean a mechanical universe, no singularities or big bangs, no mystical forces. Before the beginning, there is nothing, no thing, literally. Just the void. One particle suddenly appears (yes, I know the word sudden implies time but it means it was not there and then it was, gees, how do we escape time?). Does this one particle, the only entity in existence, know time? Does it have a concept of time? Can it measure time?

It can't measure anything. It could be moving at the speed of light but would not know it. This is because measurement is based of the difference between things. It takes two things to have a concept of motion or time or size or anything. All of mathematics is based on differences. The number line itself is a series of differences (between any value and the origin).

But, once a second particle comes into existence, the two can measure the differences between them and start building concepts.

So we have to admit that there are no absolutes. Only differences. And it is the differences that mean things, not the similarities (although they are not completely worthless). (Funny how, as a society, we are made to conform and so minimize differences where as everything else relies on seeing differences and making use of them. But I digress.)

Can two entities measure a difference in time? Meaning can one of them experience time differently than the other. No. They may have different standards for time but they will always be linked by some transformation.

What I am getting at here is that anything we measure is a difference between at least two things. If something is fundamental then it must not depend on anything else. Therefore time is not fundamental. It is not a dimension. Talking about frequency is even worse as a frequency is an interval of time that must pass before something happens. It depends on time for its definition so it can't be time or create time.

Did that help us define time in any way? I think it allows us to remove some options from the board but maybe I have missed something. It leaves me with an understanding of time as a measure of change, which is just motion. However, it is a second order measurement as we can only define time as being how long it took something to move from HERE to THERE, which we must remember is actually an interval. It takes two measurements of location to define a standard time interval but this in no way defines time itself and certainly does not impose limits on it, only on our measurements. This removes all arguments of time being quantized. Only a time interval can be quantized and it would be pretty useless if it wasn't quantized. Since all math in physics is (should be) based on measurements then I would expect the math to see time as quantized. But this does not tell us that time itself is quantized.

[StevenJay]

My very favorite Zen quote (typically, a very nebulous answer to a very nebulous question):

"Everything is at the same time. Nothing is vice-versa."



You just gotta love those guys!

[david barclay]

A thought;
Time is not an event, like the weather, but a phycological phenomenon. When you are doing something you enjoy, time flies. When you are waiting in the dentist chair listening to the drill, time drags on. If we did not have any watches, how would we cope? Just because the sun takes 365.25 days to go around the sun and the earth takes 24 hours to rotate once on its axis is not a definition of time. If we had evolved on a different planet with different rotation aspects, out concept of time would be different.
There is now such thing as the past or the present, the current moment,now, is all you have. To think about the past so make it real is always in the present moment. To think about the future and when that point is reached, it is always in the now, the present moment.

Working out the electric universe is easy compared to working out what time actually is!

Tesla
"The most uncommon thing is common sense."

Hi there tesla, if all we have is the present we have nothing because there is no possible manner by which to determine an absolute present moment, which is what would be required to sustain the present if that's all there was, in which case the universe would be frozen or stuck in a rigid state.

If we have both a past and future, this allows for a flow through of time as an underlying force of energy having no bearing on seconds, hours, days and years etc.

On top of everything else it is impossible to determine if we presently exist in the earth's past or future.

Of course both the past and future exist simultaneously as there is no linear duration of time involved or a linear distance. This would mean that the past and future exist simultaneous to the present and are as close as the end of your nose regardless of how we measure historical and futuristic events.

[StevenO]

You guys are both right and wrong. Time is operationally equal to a distance. But since all matter (at least locally here on earth) is expanding at 9.8 m/s^2, past time is compressing inside matter at this acceleration and future time is compressing towards us at that acceleration. You explain me how one can turn that into time travel. Photons are the relative 'now' compared to that expansion of matter. In that sense a WMAP plot could be seen as a map of the future.

[david barclay]

StevenO,

You say time is operationally equal to a distance, but all distance is not equal.

We make a huge assumption that time and distance remain equal regardless of how far from the earth we travel, whereby we assume light speed to remain constant from one position in space to another.

For this to be so requires the universe to exist in a static state, but no static state exists.

Past is not compressed inside matter, whereas the future is focused to the core of all matter..

The expansion factor must correspond inversely to the acceleration of time as an underlying force of energy determining the form and function of all physical structure.

Time/line differentials exist between all systems of universe, whereby time travel is simply a process of shifting from one frame of reference to another, but regardless of whether you find yourself in the past or future you will always perceive yourself existing in the present.

It is interesting to note that there is no known manner by which to determine if we presently exist in the earth's future or past, all we know for sure is that we perceive ourselves to exist in the present. But whether our perception of the present corresponds to a point in the earth's past of future is uncertain.

[StevenO]

StevenO,

You say time is operationally equal to a distance, but all distance is not equal.

We make a huge assumption that time and distance remain equal regardless of how far from the earth we travel, whereby we assume light speed to remain constant from one position in space to another.

For this to be so requires the universe to exist in a static state, but no static state exists.

Dear David,

You read more in my sentences than I wrote I think. I mentioned earth, since I cannot be sure if the gravitational expansion is different at outside our solar system. That time is operationally equal to distance can be shown by the example of a car accelerating in a straight line, to be able to differentiate that twice to the time variable to get the distance covered the arrow of time has to run parallel with the car, otherwise the car would curve. That also invalidates Minkowski's hyperbolic spacetime math.
I do not know why you assume that constant lightspeed and constant gravity requires the universe to be in a static state, since velocity and acceleration require a change of state IMHO.

Past is not compressed inside matter, whereas the future is focused to the core of all matter..

Ehhm, looks like you partially agree with me and partially not. If matter is accelerating outward, my position is that the past of matter leaves a trail inside it and the future of matter is indeed the outside world focused on the core of matter.

The expansion factor must correspond inversely to the acceleration of time as an underlying force of energy determining the form and function of all physical structure.

If you mean "acceleration of all matter" here then we are on the same line.

Time/line differentials exist between all systems of universe, whereby time travel is simply a process of shifting from one frame of reference to another, but regardless of whether you find yourself in the past or future you will always perceive yourself existing in the present.

This sounds like mainstream physics blah to me. What is your definition of "reference frame" here? What is the "process of shifting"? A gedanken experiment? Or something physical? I agree with you there is only "now" for all observers in the universe.

It is interesting to note that there is no known manner by which to determine if we presently exist in the earth's future or past, all we know for sure is that we perceive ourselves to exist in the present. But whether our perception of the present corresponds to a point in the earth's past of future is uncertain.

Every "observer" will perceive himself in the present with the past speeding away at lightspeed into memory matter and the future coming towards him at lightspeed from all directions, unchangeably.

[david barclay]

StevenO

I apologize for the confusion, I misunderstood what you were getting at.

The speed of the car thing....yes that is a linear relationship, which is handy in respect to its application, but I made the mistake of assuming we were past that point.

My fault again, for light speed to be considered a constant requires the speed of light to remain static.

This static state was Einsteins original idea, as he viewed the universe as static, which in turn allowed him to cast light speed as a universal constant, but in later years he did an about face.

This may be where some of the confusion arises as his 4 dimensional space/time continuum is based on a linear relationship, which gives us a very false sense of universe.

[david barclay]

Time/line differentials are hardly mainstream physicas.

I wrote an article on this subject for Nexus Magazine 18 months ago. If you want to read the article I have it posted on my blog http://www.gravityc-idealism.blogspot.com