Universal time constant

[modest]

Originally Posted by eloxer

I would like to add two or three remarks on that subject:

- In computer simulations you can compute a relativistic universe in rounds. Every state is computed from the previous state. These steps (or epochs) are the universal time. They can be quite tiny (meaning only few changes or small numeric changes to an otherwise discrete model - by the way: time is a property of discrete models alone - another indicator that the universe should be discrete and should not know continua). If you add distance to play a delaying role in interaction among particles, you'll get a relativistic model. Any complex structure on the inside cannot experience proper time now, since it must rely on state change comparisons, that are relative to speeds and distances. If that simulated structures were human creatures, they would have no means to measure this universal time.

There's no need to say structures can't experience proper time - that just opens up a valid objection for someone who wants to disagree with you. Your conclusion here, that nothing has the means to experience universal time, can be proven using only proper and coordinate time. Since these are both well defined and it's most difficult to solve GR with motion and mass, the proof would go something like this

The difference between proper time (which objects experience) and coordinate time (or global time) is:

where:
is proper time,
is coordinate time,
and is a component of the metric tensor.

In the schwarzschild metric:

which means every area of space is time dilated by:

Since every area of space is at lest some distance r from some mass m then there is nowhere in our universe that experiences coordinate time. So, we can say with confidence that no clock in our universe keeps global time... If we're saying there's a timekeeper outside the universe, well then, I wouldn't know how to make a proof for that

Originally Posted by eloxer

This argument is sometimes used by people who do not want to care and take responsibility (I didn`t see the guys beat the girl up). They just shut their eyes, so they don`t have to bother. It also reminds me of the behavioristic approach in psychology, where we know today, that behaviorism clearly has its limits.

A difference of opinion is good. It stimulates scientific debate. It hardly needs such a description. You also might consider that your idea says something exists which no one can measure or experience in any way. So, people might have some valid objections to that.

~modest

[LaurieAG]

Hi Modest,

Originally Posted by modest

Your conclusion here, that nothing has the means to experience universal time, can be proven using only proper and coordinate time. Since these are both well defined and it's most difficult to solve GR with motion and mass, the proof would go something like this

That's a good structure for a proof although the practical application would work more like satellite systems.

I read an article recently about how one of the latest GPS systems triangulates the times from 3 satellites with a fourth as a further check calculation to get a resolution of 10 meters.

Originally Posted by modest

Since every area of space is at lest some distance r from some mass m then there is nowhere in our universe that experiences coordinate time. So, we can say with confidence that no clock in our universe keeps global time... If we're saying there's a timekeeper outside the universe, well then, I wouldn't know how to make a proof for that

That depends on how we define universal boundaries, especially if we use the proximity to mass ratio (m/r) as a guide for the boundaries of objects that can have no physical interractions (apart from sending photons) with others because they are too far away.

So a timekeeper, or a series of timekeepers, outside the influence of physical interractions with other objects with mass, could be expected to operate in an environment where time dilation is minimalised (as per your last equation), compared with other areas, and therefore still follow your proof structure.

A series of timekeepers in these boundary locations would be able to keep global time and, just like the GPS methods, their timers could be used by other objects to triangulate a relatively absolute position (as long as the timer positions don't spin).

[modest]

Originally Posted by LaurieAG

That depends on how we define universal boundaries, especially if we use the proximity to mass ratio (m/r) as a guide for the boundaries of objects that can have no physical interractions (apart from sending photons) with others because they are too far away.

A clock by itself in a universe all by its lonesome would keep its own global time - granted. That's unrealistic and hardly needs said.

Originally Posted by LaurieAG

So a timekeeper, or a series of timekeepers, outside the influence of physical interractions with other objects with mass, could be expected to operate in an environment where time dilation is minimalised (as per your last equation), compared with other areas, and therefore still follow your proof structure.

A series of timekeepers in these boundary locations would be able to keep global time and, just like the GPS methods, their timers could be used by other objects to triangulate a relatively absolute position (as long as the timer positions don't spin).

I explicitly said in my post above that the proof doesn't apply for a clock outside the universe. The boundary condition you're proposing (outside the influence of any matter) is no different. You want to isolate a clock by itself and at the same time say it measures some property of our universe - that's not coherent.

~modest

[Erasmus00]

Originally Posted by LaurieAG

relatively absolute position

That phrase is a contradiction in terms. You can't be relative and absolute.
-Will

[LaurieAG]

Hi Modest,

I'm glad that you have been following the 'Universal Scale' thread along with Reason.

I'm still reeling from modest's explanation that I am larger compared to a plank length than the entire universe compared to me.

In reality we can never reach absolutes but in practice 'near enough is good enough' for an extremely large proportion of the time, especially on the atomic scale. I would think that, considering your explanation, you would realise that we probably have better odds on universal scales verses atomic scales?

Originally Posted by modest

A clock by itself in a universe all by its lonesome would keep its own global time - granted. That's unrealistic and hardly needs said.

If you define your universal boundaries according to the physical proximity to mass and, just as we use the Planck length as a scale boundary, our 'universal' boundary is reached at the certain 'tipping point' where objects with mass can have no possible physical influence on objects at the boundary.

Originally Posted by modest

I explicitly said in my post above that the proof doesn't apply for a clock outside the universe. The boundary condition you're proposing (outside the influence of any matter) is no different. You want to isolate a clock by itself and at the same time say it measures some property of our universe - that's not coherent.

As I said before, we cannot reach the absolutes of our 'physical universe' but we can get close enough to make things happen. Albert Einstein never claimed that an absolute singularity could be reached, he only thought that you could approach it.

Considering the total lack of anything absolute in our universe, including its boundaries, and the amazing things humans have done (both good and bad) despite this limitation, I don't know why you think something like a linked network of timesignal beacons that operates in the closest thing we'll ever get to a pure vacuum, could not be regarded as a coherent solution.

For all we know it may already exist, I don't really know.

[LaurieAG]

Originally Posted by Erasmus00

That phrase is a contradiction in terms. You can't be relative and absolute.
-Will

Hi Erasmus,

I didn't mean relatively (to the speed of light) absolute because that is exactly what you claim. I mean relatively (close to the absolute) absolute which is about as far as we do go and can ever go.

[eloxer]

Originally Posted by modest

Since every area of space is at lest some distance r from some mass m then there is nowhere in our universe that experiences coordinate time. So, we can say with confidence that no clock in our universe keeps global time... If we're saying there's a timekeeper outside the universe, well then, I wouldn't know how to make a proof for that
~modest

Your proof looks right, but that's not the point, because the tensor mathematics and GR were developed just in such a way that they provide you with this (by observation correct) kind of result. Tensor mechanics are result of a specific model, where one does not want to care about possible implementation of the universe (Mathematics IS the science that is supposed to hide details behind a model in order to predict future "observations"). The tools were developed in order to predict future observations. BUT if somebody (philosophically) asks, if there is a universal time, then mathematical deduction is just to little. One must get into the model discussion and find a model that explains, why the universe occurs to us in an absolutively relative manner. And yes, you are right, even when you had this universe simulation at your PC's desk, you would not be able to make a proof of it. Reality and its mechanics are given things, not things to be proven. To prove, that a mathematical model is coherent with other mathematical assumptions is the job of the Proof-Theory (mostly deduction - this is what you did nicely). One must use an experiment in order to show coherence of model and observation. (This is what other people have done a lot, nicely)

So what is time? We often think of time as a sequence of states. That's a valid global notion of time. If our universe is indeed a discrete simulation, then universal time is an integer describing which state the universe is in, no matter whether the universe's value has changed or not. Ten subsequent generations of the same values describing a universe means that the absolute time has gone forward by ten units, while the time within the universe has gone zero units (some hypothetical extreme example that produces an extreme time dilation)
But in physics we ask how do we observe time? Here the question and the answer is quite different (no matter whether the universe was Newtonian or relativistic): Any entity that "observes" (be that an electron whose observations are electric and magnetic "input") perceives time as the ratio of input signals to own states. If the recorded input drives the electron's answers then the observation ratios influence the actions that the electron will undertake (if we put it equal with some software agent). The observation of time is based on this kind of observation-relationships among entities and therefore observable time is relative by nature.

Gedankenexperiment:
There is an electron that flips its spin up and down every step of the simulation. Then nothing can be said about the "speed" observed by an entity within the universe, when we can not say at what rate new unique states are achieved by that entity (not even mentioning aliasing). If that entity was a human and it took human neurons to perform a switch in 100 jiffy cycles and in other case in 1000 universal time cycles, then the observed speed ratio is ten. If we assume that the variables influencing neuron speed also influence all other local interactions (like the mass of the nearby planet) then measuring apparatus is influenced equally.

This is what I mean by saying, that providing humans with a hacked access to the universal clock would not help them make any kind of predictions about their environment. Probably the absolute time exists, but is quite pointless for us to know it. So this is kind of also the argument why I don't like astronomers compute how old the universe is. This number is guaranteed to be wrong - if not even on orders of magnitude. Saying that something is 10000 years old tells us that on earth, where the gravitation has been similar since then, 400 generations of people existed and therfore had 400 times the chance to change either culture or genetic material. But in the whole universe, where things are not so homogeneous, what does it mean 14 bilion years or 7bilion (of earth-) years? It is quite nonsense apart from the fact, that it assumes a specific kind of big-bang model.

Nothing is wrong with math, we should use it more!
Best regards,
eloxer.

[raymond723]

I don't know what do you mean by