Fourth dimension=time?

[LaurieAG]

Hi Moontanman,

Originally Posted by Moontanman

What version of reality you subscribe to, BB, BV, membrane, Static, no mater which one time is active in all of them and none of them can work without a concept of time.

What i wan to know is this, is time a dimension, an emergent property, or a basic property of reality?

After reading all the posts in this thread i say time is a basic property of the universe no matter what it's reality is.

While time may be a property of all theories the reality is that the speed of light is what actually changes in relation to its proximity to mass, not time itself. Therefore in the concept of space-time, time is paradoxically different to when time alone is used as a separate dimension on its own.

[modest]

Originally Posted by LaurieAG

While time may be a property of all theories the reality is that the speed of light is what actually changes in relation to its proximity to mass, not time itself.

Yeah, and lines of longitude seem closer together near the north pole versus the equator because the speed of a plane flying east-west near the pole is greater (in degrees of longitude per hour) versus the speed of an equivalent plane flying east-west over the equator (in equivalent units). Yup—it's the speed of the plane that actually changes in the two locations, not the degrees of longitude themselves.

That's a good point Laurie, and not troll bait at all—seems directly related to what MTM said. Huzza!

~modest

[Qfwfq]

Actually it's called the VSL interpretation of General Relativity and some serious folks have investigated it. However, it isn't quite the point of this thread and, also, Laurie's wording smacks of a claim rather than a quite controversial alternative model.

[modest]

My understanding is that VSL is not an interpretation of GTR. Only by confusing coordinate speeds with velocities (which I possibly failed to analogize well-enough in my last post) can such a comparison be made. VSL is, I think, an entirely separate model.

~modest

[Qfwfq]

I think VSL is so controversial mainly because there is so much confusion and misunderstanding about it.

"Either the well was very deep, or she fell very slowly, for she had plenty of time as she went down to look about her and to wonder what was going to happen next." (Lewis Carroll, "Alice's Adventures in Wonderland", quoted by Stephen Weinberg in "Gravitation and Cosmology")

[Rade]

Originally Posted by modest

....a good question would be: is it possible to describe reality without some concept of time?

Sure, but not in this universe, all it would require is that the 'reality' not have any motion. You see, imo, the 'now', the 'moment', the 'present' is outside of time and whatever reality is within the 'now' or the 'moment' or the 'present' can be described without time if it (the reality) has no motion. But such is not possibility in our universe for all things that are real are in motion, thus all attempts to describe reality must include some concept of time. This is how I see it, comments welcome.

[modest]

Originally Posted by Qfwfq

I think VSL is so controversial mainly because there is so much confusion and misunderstanding about it.

I guess... in deference to the physics community: rejection in the face of so much confusion and misunderstanding could be called a valid application of Occam's razor

I think Poincaré is correct here (in that the latter would be widely considered the more advantageous):

One geometry cannot be more true than another; it can only be more convenient. Now, Euclidean geometry is and will remain, the most convenient... What we call a straight line in astronomy is simply the path of a ray of light. If, therefore, we were to discover negative parallaxes, or to prove that all parallaxes are higher than a certain limit, we should have a choice between two conclusions: we could give up Euclidean geometry, or modify the laws of optics, and suppose that light is not rigorously propagated in a straight line. It is needless to add that every one would look upon this solution as the more advantageous.
-Henri Poincaré

Certainly if the flat spacetime/VSL physics is "most convenient" as he assumed it would be then I couldn't imagine it finding any controversy at all.

~modest

[LaurieAG]

Hi Modest,

Originally Posted by modest

Yeah, and lines of longitude seem closer together near the north pole versus the equator because the speed of a plane flying east-west near the pole is greater (in degrees of longitude per hour) versus the speed of an equivalent plane flying east-west over the equator (in equivalent units).

So a Cartesian projection, as opposed to a real projection, is used because it reduces the distortion of normal mapping (i.e. poles where you cannot tell whether you are arthur or martha) on a spherical shaped object for navigation purposes.

This is a problem that arises when you use a sphere as a universal model as opposed to a sphere as being a byproduct of our observation limits. All you hilight is mapping problems with sperical objects so thank you for reinforcing my argument.

[LaurieAG]

Hi Modest,

Originally Posted by modest

I think Poincaré is correct here (in that the latter would be widely considered the more advantageous):

One geometry cannot be more true than another; it can only be more convenient. Now, Euclidean geometry is and will remain, the most convenient... What we call a straight line in astronomy is simply the path of a ray of light. If, therefore, we were to discover negative parallaxes, or to prove that all parallaxes are higher than a certain limit, we should have a choice between two conclusions: we could give up Euclidean geometry, or modify the laws of optics, and suppose that light is not rigorously propagated in a straight line. It is needless to add that every one would look upon this solution as the more advantageous.
-Henri Poincaré

At the time he wrote this Poincare was unaware of gravitational lensing, i.e. the 'straight' line is bent due to the proximity to mass along its path (relative to source and viewer) and therefore, if we use Euclidian geometry consistently, it appears that the speed of light changes due to this distortion (i.e. distance travelled changes not the time it takes to travel a fixed distance).

[arkain101]

Originally Posted by Rade

Sure, but not in this universe, all it would require is that the 'reality' not have any motion. You see, imo, the 'now', the 'moment', the 'present' is outside of time and whatever reality is within the 'now' or the 'moment' or the 'present' can be described without time if it (the reality) has no motion. But such is not possibility in our universe for all things that are real are in motion, thus all attempts to describe reality must include some concept of time. This is how I see it, comments welcome.

If we consider time a property type of concept, then motion isnt really the key relationship to be associated is it?

It seems to me that a universe with no time only requires that it have no mass. In our universe, if we try to move something, it responds proportional to the time of change. If we move something quickly it resists more, than if we try to move it slowly.

If we had a universe with no mass, the rate we moved anything would have no dependency on the concept of time.

Furthermore, isn't motion something that is determined strictly by the mind?

For example: If you have ever played a video game online, you might have experienced a lagging effect. Lets use the imagery of a person moving about a surface. When there is no lagging occuring the person moves smoothly, at some 60 positions per second (lets say). Now, lets keep adding greater and greater (packet loss of information).

Packet loss at 25%. The person moves about the surface in chunks of pictures separated by a distance of some 5 feet, seemingly in somewhat of a motion.
Packet loss at 50%. The person warps around the surface, and it becomes harder and harder to discern the path the person has took to get from A to B, pictures separated by 15 feet.
Packet loss at 90%. The person appears in entirely random locations, and has no motion at all, we see a freeze frame picture every (1 second) persay.

The only information being computed is 10% of the possible information for the system. We lose the concept of motion with the loss of information, and our ability to predict the path and direction of the motion decreases with the loss of information.

I am no quantum physicist, but it is my understanding that a very similar effect occurs when we try to observe motion(or momentum) and position. Furthermore, electron orbital 'shells' change instantaniously in a kind of series of blocky of forms, instead of a fluid change.

So I wonder, how much credit should we give to the idea of motion (that is a motion concept beyond our minds intuition of distance to time change)?

And secondly, some physicists have said "time is something that prevents everything happening at once", however, anything that happens only happens at once, if we don't apply a world view to the universe, then wouldn't it all just happen at once?

Its tricky to discuss, because it seems time is related to mass, and yet, is also a part of a minds world view.