Defining Time

[WebFeet]

There have been many post here and elsewhere concerning Time and if it is the fourth dimension or merely perceived by us to determine how old we are getting.

But there is a clear definition of Time and it is my view that from this definition, Time should be view not as an additional dimension, but rather as the foundation on which we define all other dimensions.

From Maxwell's work with electromagnetic fields we are given the equation to calculate the speed of light based on the properties of free space

Maxwell calculated that the speed of light was inversely proportional to square root of the Permeability and Permittivity of free space.

C = √ 1 / µ οε ο

Using the equation speed = distance / time, would define Time as being the product of µ ο and ε ο

Permeability is the ability to allow the passage of one media through another, while Permittivity determines how much or at what rate this takes place.

Now since Maxwell was working with electromagnetic forces, the permeability and permittivity was to do with the magnetic fields, or in other words, photons.

So, based on this, Time is defined by the rate at which photons can permeate free space.

[maddog]

Originally Posted by WebFeet

Permeability is the ability to allow the passage of one media through another, while Permittivity determines how much or at what rate this takes place.

Now since Maxwell was working with electromagnetic forces, the permeability and permittivity was to do with the magnetic fields, or in other words, photons.

So, based on this, Time is defined by the rate at which photons can permeate free space.

I followed you until here.

Permeability mu0 is specifically with magnetic fields and Permittivity nu0 is with electric fields.

Time defined simply as such implies to be independent of observer. By relativity it is know not to be. The
speed of light in free space is fixed, the passage of time wrt to an observer is not a fixed rate. Here the I
becomes important.

Maddog

[Thelonious]

In the words of Carl Sagan, "Time is resistant to simple definition."

Amen.

[KickAssClown]

Originally Posted by maddog

I followed you until here.

Permeability mu0 is specifically with magnetic fields and Permittivity nu0 is with electric fields.

Time defined simply as such implies to be independent of observer. By relativity it is know not to be. The
speed of light in free space is fixed, the passage of time wrt to an observer is not a fixed rate. Here the I
becomes important.

Maddog

It's simple Take a look at my post here:
http://www.hypography.com/sciencefor...ead.php?t=1390

and time is definite. hence the speed of light. it's distance that isn't.
Read up on relativity people:
http://www.hypography.com/sciencefor...ead.php?t=1390

[BlameTheEx]

Webfeet

Interesting thread you have started.

The question here might be one of cause and effect.

Can the permeability and permittivity of free space can be defined and measured WITHOUT reference to C? If not we have to consider the possibility that these constants are the product of C and something else which is independent of C. In that case they will not define C at all. C will be defining them.

I am playing devils advocate here. It could be you are on to something.

[WebFeet]

Originally Posted by maddog

Time defined simply as such implies to be independent of observer.

For there to be a fundemental definition of Time, it would have to be independant of observer.

Originally Posted by maddog

By relativity it is know not to be. The
speed of light in free space is fixed, the passage of time wrt to an observer is not a fixed rate. Here the I becomes important.
Maddog

With respect to Relativity, whether general or special. you have additional factors that need to be taken account of, be they velocity or gravitation fields. Here your frame of reference is relevant. For the definiton of Time, there need be no view point.

Originally Posted by BlameTheEx

Can the permeability and permittivity of free space can be defined and measured WITHOUT reference to C? If not we have to consider the possibility that these constants are the product of C and something else which is independent of C. In that case they will not define C at all. C will be defining them.

It is possible that the answer is circular.

What if there is no something else, but that all we are dealing with here is energy and how it permeates through free space. Permittivity and Permeability may be two sides of the same coin.
As with gases, there more gas you try to contain within a volume, the less permeable the volume becomes. If you increase the pressure in the volume sufficiently, you will alter the volumes state from gas to liquid and eventually solid. Each step decreasing the permeability.
If free space and energy work in a similar fashion, then the more energy contained within a volume, the less permeable it becomes. After all, gases at their fundemental level are only energy.

This would imply that any fluctuation in permeability would result in a variation in the speed of light. We are reasonably confident that the speed of light is constant.
What would change would be the distance over which the velocity wold be measured.
The majority accept the concept of spacetime bending due to gravity wells, and in this environment distances become compressed, so the same could be said of changes in permeability which would ensure that no matter what its value was, it would always appear to be constant.

So the answer as to how fast light can travel depends on how much light there is.

[maddog]

Originally Posted by WebFeet

For there to be a fundemental definition of Time, it would have to be independant of observer.

Inherant to SR, the reference of time is tied to an observer. Thus by your definition there
would be nor fundamental definition. Were come up with one adhering to both SR, GR &
QM + QFT and Standard Model, I would like see it (even only some of the above fields).

Originally Posted by WebFeet

With respect to Relativity, whether general or special. you have additional factors that need to be taken account of, be they velocity or gravitation fields. Here your frame of reference is relevant. For the definiton of Time, there need be no view point.

See above. Only Classical Newtonian physics is there an Absolute time independent of
the observer frame of reference.

Originally Posted by WebFeet

So the answer as to how fast light can travel depends on how much light there is.

I believe you will the speed of one photon will travel at the same speed as the beam of
laser light when in the same medium (be that of c in a vacumn).

Maddog

[WebFeet]

Originally Posted by maddog

Inherant to SR, the reference of time is tied to an observer. Thus by your definition there would be nor fundamental definition. Were come up with one adhering to both SR, GR & QM + QFT and Standard Model, I would like see it (even only some of the above fields).

See above. Only Classical Newtonian physics is there an Absolute time independent of
the observer frame of reference.
Maddog

All of your above examples use reference frames to be able to measure time, not define it.

Originally Posted by maddog

I believe you will the speed of one photon will travel at the same speed as the beam of
laser light when in the same medium (be that of c in a vacumn).

The question is not how fast it travels, but what prevents it from travelling at a different velocity ?

[BlameTheEx]

WebFeet

As a matter of fact I have argued long and hard for the idea that perhaps gravity DOES reduce the speed of light. It works out just as well as arguing that it warps space, and it is a lot easier to understand.

The argument goes this way.

1) it would account for gravitational lensing.

2) The kinetic energy gained when an object falls into a gravitational well is balanced by loss of potential energy. It starts with the energy of its mass as E=MC2. Inside the gravitational field C is reduced, so the potential energy associated with the objects mass is also reduced. The maths works if one of the two C's in that equation is the local speed of light.

3) It accounts for gravitational time dilation. Dilate C and time must follow.

[Turtle]

Your mention of permiability brings to mind the area of math called "Percolation Theory". In this field one investigates the spread of phenomena; ie. forest fires or oil deposits, through a medium(a forest or a rock formation). Since you have described a situation in which it appears light is percolating through a medium, perhaps some of the equations from this area may serve to model light as well.