Hans

Relativity seemingly incontrovertibly defines time as that which is measured by a clock.

Relativity shows us that time will slow down or speed up relative to other coordinate systems. One instance of when this happens is when there is a difference in gravitational intensity between the two systems.

Time between two systems would look something like the below if one were in a strong field (A), and the other in a weak field (B).

A Start . . . . . . . . Finish
B Start.................Finish

Under the appropriate gravitational difference time in A would progress at exactly one half the rate of B. Oddly enough, though, at the finish of the observation both systems would exist in the exact same present. System A will not be in the past relative to System B. Furthermore, if a small difference does not place System A even slightly in the past relative to system B, then it can safely be assumed that no matter how great the difference, even if the progression of time in system A was said to be zero relative to system B, they would still both exist in exactly the same present.

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There is another seemingly incontrovertible definition of time. That which separates the past, present, and future. Relativity has shown us: That which is measured by a clock does not measure that which separates the past, present, and future.

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The argument against infinite regression is that in order to reach the present, an infinite series of events must have already taken place. It is argued that since an infinity has no end it can not be completed. Therefore, our history must be finite in order for the present to exist.

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If that which separates the past, present, and future is independent of that which is measured by a clock then it can be argued that the past can be infinite regardless of that which is measured by a clock.

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Infinite regression, the unending series of events that precede each other, like that which is measured by a clock, is independent of that which separates the past, present, and future. All events in system A will slow relative to system B.

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The universe can have an infinite past without infinite regression.

Chew it up everyone!

[ June 04, 2002: Message edited by: Hans ]</p>

a_j_ayer

Along everyone else should, I like to speculate on relativity and all that.

Yes, the idea of infinite time without infinite regression is interesting. However, General Relativity is not dependent on a co-ordinate system, as most tensors are idependant of coordinate transformation. But I agree with everything you have said, save for some of the implications.

There is no possable observation outside of the universe (as far as we know). So we must consider the system inside the universe. In itself, that co-ordinate system yeilds some interesting things. It implies an uncaused universe.

One has right now an expanding universe, and if onw looks at the universe with negative time direction one finds that the universe is contracting. This suggests that the universe was at one time a single point, if you extrapolate far enough. that single point would have high gravitation, and this would suggest a small boundary value on the time dimension. This would appear to us as slowing of time, but really it is just the warping of the dimension. If the universe is extrapolated to infinite gravity, and therefore infinite warping, it could have started without anything starting it.

I think this makes more sense than describing the time passage as something that has slowed to become infinite. The math doesn't really work, but it is a very good notion to think about. It might appear infinite only because the dimension itself would have warped to the point that a light cone would have formed the shortest possable line in Lorentz co-ordinate system.

Like I said. Fun stuff to think about.

Ayer

AlphaFraktaL

Suppose that one defines time as an additional Euclidean dimension and make this relative to one position at any given point. This means there exists a four dimensional vector defining an event (position, time). It should be possible in my mind to define the position of any event in the universe based upon a manifold mapping unto non-Euclidean space (Treating it as a 4-Manifold). Thus time is a positional element of a vector that maps events in history.

Implications of this idea:

-Velocity is an examination of a series of events and thus arises naturally as the time dilation/ length contraciton distortion. In my mind there is no proof in the nature of relativity for infinte regression or against.

-An event is still an event that can be mapped unto the manifold. Since time is defined by a unique frame, there should be no suprise that a gravity field delays time as described, and yet the mapping of the Lorenz-cone does not change.


Looking back on what I wrote, it seems like gibberish, but I guess in short what I am trying to say is that we cannot know the nature of the manifold that maps the universe beyond an idea of basic gauge theory forces. Thus, time very well could exist to us as infinite (or even modular!) should the manifold be shaped correctly.

Nuff' said.
Fun speculation

FraktaL

h

Hans,
Maybe I'm wrong, but I think you were slightly mistaken. From my understanding of relativity, "System A will not be in the past relative to System B" is wrong. It seems that only in the case that the "present" should be defined outside the coordinate system that such an argument would have merit.
Activity in system A will fall behind that of system B, regardless of whether the lagged relationship can be noticed in system B (due to a gradual equalizing of fields that will take place between the two). However, many smartfucks have speculated that if one were to look back upon the normal universe from within the grasp of a black hole, things would appear to develop at astonishing rates. Hence, the onlooker might see what would have been his future while those in the normal universe reflect on the retards that fell into a black hole 500 years ago.

Hans

It is the observation of experiments performed to demonstrate time dilation that seems to show there is a universal "present" that is independent of how individual coordinate systems measure time.

Two example experiments are:

1) Placing one clock at the top of a tower and another clock at the bottom of the same tower. This experiment measures gravitational time dilation.

2) Placing one clock in an airplane and the other in the airport. Measures both gravitational and velocity time dilation.

In each experiment both clocks can be brought from their relative locations and placed next to each other on a table. In each, the clocks would still show the difference in elapsed time yet exist in the same exact present. Hence my thought that time dilation, or that which is measured by a clock, has no effect on that which separates the past, present, and future.

a_j_ayer

Originally posted by AlphaFraktaL:

"An event is still an event that can be mapped unto the manifold. Since time is defined by a unique frame, there should be no suprise that a gravity field delays time as described, and yet the mapping of the Lorenz-cone does not change."

A very interesting addition to discussion. But it seems (maybe I am very-much off base) that you do not think Euclidean space can intersect Lorentzian space. The post you made was very good for discussion, but since it is speculative (of course) it is very hard to read. That is, of course, not your fault.

The main reason why I think that time is not infinite is because that is what would be suggested with reversal of time by just looking at the metric tensor.

The metric tensor has {-1,-1,-1,1} on the diagonal (you understand why I don't write out the whole think, as a matrix would look funny). We just analyze it as it moves backward along with the Christoffel differential and the stress tensor T{mu,nu}. The Reimann-Christoffel Tensor is an appropriete substitute for the Christoffel differential here.

When (mu,nu) = 0, we find (Gravitation by Misner, et. al.) that -3 d^2(a)/a = 4(pi)G((rho)+3(rho)). This is a very useful localiation upon the -1 parameter. When further described upon the other three parameters (1,1), (2,2), and (3,3), we find that for the first two we have d^2(a)/a=-4(pi)G/3((rho)+3p), and (da/a)^2=8(pi)G/3*(rho)-k/(a^2), which applied to the basic Klien Metric yeilds H=da/a (H is the Hubble constant, a is the radius universal, (rho) is universal density, k is -4(pi)G/(c^3)).

That is the math. It suggests that:

(OMEGA)-1=k/(H^2a^2)

Where the famous OMEGA constant comes to a flat, open, or closed universe. So far, evidence suggests an open universe, and not one that is globally Euclidean when d/(dx(alpha))(GAMMA){alpha;mu,nu}=0. When a = 0, we have a singularity called the Big Bang. When one looks at the time geodesic in Lorentzian space, one finds of course a collapsed cone. However, because d/(dx(alpha))(GAMMA){alpha;mu,nu} (less than) 0, representation of time as euclidean would be impossable. Even looking at it with a basic Schwartzfield metric, we find that c^2dt^2, like all the rest of the coordinates, must be zero.

This finally suggests that no time is passing. A good conceptual way to view it is that with a singularity, all parts of space and time are "wrapped around" it, and therefore have no length. Euclidean representation at singularity is impossable.

But if you don't accept big bang (and there are alot of good evidences TO accept big bang), the OMEGA constant could be either = or (greater than) 0, allowing for an open or flat universe. However, some interesting questions (acceleration of universal expansion, and radiation background) are left unanswered.

Also, assuming an infinite time between big bang and now doesn't really work, because we still see darkness in space suggesting limits to either space or time values, and since the universe is expanding with this background radiation, probably both (though I suppose it could be limitless and still bounded... damn Hawking!).

It is fun again to speculate.

Ayer

AlphaFraktaL

Ayer-

Totally catch on to what you are saying, bad wording on my fault.

Basic suggestion lies in this (and bear with me cause I'm just an undergrad trying to sort things out). Reality has the ability to be defined in terms of events and nothing more. Suppose that one wants to define an event: use 4 orthogonal terms even though this is not fully reality- it is how our perception would naturally want to define an event. Could then our perception be mapped unto reality through use of a smooth differential 4-manifold?

Cool thing about this: This means that the whole idea of a Lorenz cone would be based upon the mapping of a cone in our percieved four dimensions. Suppose we take the cone and map it onto unto a 4-manifold that may distort it. Not much content there, dont know why I included it, but it seems sort of neat.

I am going to look into see if I can find the textbook/article with "Gravitation" by Misner, et. al. so I can enlighten myself as to a few of the terms that you used in the math. The questions I have in general right now are:

Is it possible since a Big Bang could be a non-singularity (around Planck's length, by String Theory from what I understand?) would percieved time still flow and could it potentially be infinite such that we only see time in which there are messenger particles?

Is time defined by messanger particles or the other way around?

Could the 4-mainfold mapping for events perhaps overlap like a sphere such that universe is modular in nature?

Lookin' into it more... if there are any articles, textbooks you can suggest, I'm open to 'em. Thx!

-FraktaL

Mr. Sammi

TIME & RELATIVITY
I am taking a slightly different tack, before we get to the physics...

What I think should be edified is what can be construed as the means and ends of time. To ballyhoo the position of ends in relation to time means I surrender to the ideal of seeing time on a clock. The existential of its ends lies on the face of the clock and includes all the parts which signal NOWtime. What is seen on the clock is extrinsic to the solipsist and has value to the solipsist only in the world in which the clock exists. We know the clock fades when the solipsist closes his mind to external experience.

Here we have the interesting point of time and what it is when there is no wall to hang the clock. In your mind and what is there to be percieved, what is the relation to what the clock is expected to express, and what is expressable in the mind? The time the clock is telling, what is it? can we get a closer look by comparing what is identical within the mind to the clock on the wall? Is the clock in the mind - perception instants?

If gravity can affect the way our physics work, a phi effect, would it affect the way our perception instants crystalize? IS it slowing the clock on the wall because the rate to feed the electric hand is slower and all we had to do was push-button the electric feed and the clock would be showing time we were accustomed to seeing. This is the flow of experience. The density of this experience in relation to its flow gives an indication of the time factors at play.

Can we then call the clock on the wall the measure of the flow of experience. This would be the ends of time, which can be reiterated as measuring rates of experience, or even cycles of
experience. It is easy to see how we flood our mind with different concepts of time. If it is used as a measure of the flow of experience, then the cycles, and rates within the experience is a qualification of the flow of experience, and in essence gives knowledge about the flow of experience. This means in these cases we use time to indicate the information and some knowledge associated with the information,together at the same time.

Is this flow of experience IMAGINARY? as many claim time is imaginary. How is this experience of the flow of experience affected by speed?


[NOWtime - used to indicate the present position of the perception in direct relation to the simultaneity with which who percieves exists as a part of the simultaneity. The solipsist must agree that NOWtime occurs in the instants while the brain is working to produce thought and actions.]

Sammi Na Boodie ()

ps. I am interested in arguing against the concept of NO TIME PASSING. If no time passes then it has to be some intellectual version of the concept of time. Does anyone here believe we can unravel the information from the knowledge when it comes to us talking about time...

[ June 07, 2002: Message edited by: Sammi ]</p>

jenn

Sammi,
I wish I could have said it better!! That was a great analogy of the way people think and completely talk theirself into confusion...I know I do!! For a confused person, I find it to be very interesting!!There is a perception of time. Therefore the past, present and future are also perceptions.Which are we living in? <img src="graemlins/notworthy.gif" border="0" alt="[Not Worthy]" />

Liquidrage

I reject the conclusion of the original post by Hans because I do not accept the definition of time in the context used.

I accept time as the result of a change in entropy with the flow regulated by entropy.

In our universe it appears that entropy is increasing since our universe is expanding.
Thus our flow of time from past to present to future is a result of increasing entropy.

If one were to suggest that time had no beginning one would have to assume that at one point in the past, the entopy of the universe reversed direction without reaching zero.