Understanding what time is and its causality is not easy in part because it is something that cannot be seen or touched. For example some define it only in the abstract saying that is an invention of the human consciousness that gives us a sense of order, a before and after so to speak. In other words most do not perceived time as matter or space but as an irreversible physical, chemical, and biological change in its physical properties.

However this is in direct conflict with how physicists define it in terms of the physical properties of a space-time dimension.

For example Einstein believed as the following quote demonstrates that time was a rigid physical component of a space-time environment defined by both his Special and General Theories of Relatively.

"Since there exists in this four dimensional structure [space-time] no longer any sections which represent "now" objectively, the concepts of happening and becoming are indeed not completely suspended, but yet complicated. It appears therefore more natural to think of physical reality as a four dimensional existence, instead of, as hitherto, the evolution of a three dimensional existence."

In other words according to Einstein the structure of space-time is ridge while the changes we perceive are merely an illusion similar to the illusion of change created in a **flip book** when one rapidly flips through its pages containing series of pictures that vary gradually from one page to the next.

However if one considered blocks of space-time as the pages of the flip book responsible for the illusion of change as Einstein did one still must still define the causality of the change on each page of that book which cannot be related to time if it is a ridge component of a space-time environment.

As mentioned earlier the idea of defining time terms of the physical properties of a space-time dimension conflicts with the abstract properties most associate with change.

Yet one could resolve this conflict while defining why changes occurs in each segment of a space-time environment if one can show that change and therefore time is an emergent property of the physicality most of us including physicists associate with space. In other words if one can define the causality of change in terms of the physical properties of space then one could merge the abstract sense of order that our consciousness feels it has with its physical properties.

However to do this one must be able to understand the causes of change associated with time in terms of the perceive physical properties of space and then determine if one can integrate them into a theoretical model that is consistent with all of the other properties of that environment.

Einstein gave us the ability to do this when he defined the energy associated with change in space-time environment in terms of the equation E=mc^2 and the constant velocity of light because that provided a method of converting a unit time in that environment to its equivalent in four *spatial* dimensions. Additionally because the velocity of light is constant he also defined a one to one quantitative and qualitative correspondence between his space-time universe and one made up of four *spatial* dimensions.

The fact that the equation E=mc^2 allows us to quantitatively derive energy in a space-time environment in terms of four *spatial* dimensions is the bases for assuming as was done in the article “Defining energy” Nov 27, 2007 that all forms of change can be derived in terms of a displacement in a "surface" of a three-dimensional space manifold with respect to a fourth *spatial* dimension instead of one in a space-time manifold.

As mentioned earlier Einstein believed it is more natural to think of physical reality in terms of a four dimensional existence, instead of the evolution of a three-dimensional existence even though he did not define the causality of change in that environment.

However as was shown earlier the symmetry of his mathematics means that he not only defined that "reality" in terms of four dimensional space-time but also in four *spatial* dimensions.

This enables one to derive the causality of change most associate with time in terms of the physical properties of the spatial dimensions instead of its abstract ones.

For example one can observe how a displacement in the geometry of three-dimensional space cases change by watching water flowing over a dam.

Similarly if as was shown above one defines energy in terms of a spatial displacement in a "surface" of a three-dimensional space manifold with respect to a fourth *spatial* dimension instead of four dimensional space-time as was done in the article “Defining energy” Nov 27, 2007 one can define the transfer of energy associated with change in terms of the "level’ each segment of three-dimensional of space has with respect to a fourth *spatial* dimension. In other words change can be defined as an emergent property of four *spatial* dimensions because as one moves though Einstein’s space-time environment each successive section of three-dimensional space would be at a different level with respect to a fourth *spatial* dimension.

Granted due to the symmetrical nature of the arguments presented here one could argue that space is an emergent property of time.

However it is more consistent with observations of our three dimensional environment to assume that the changes most associate with time have their causality in the geometry of space because as was mentioned earlier we can see how that geometry causes change whereas the same cannot be done with respect to time because of its abstract properties.

Later Jeff

Copyright Jeffrey O’Callaghan 2015

There are many theories that attempt to explain what we observed in our three dimensional environment in terms of higher dimensions. However they all suffer from the same problem in that the existence of those higher dimensions are primarily based on abstract on mathematical models. The reason is because we as three dimensional beings are only able to observe objects in the three-dimensional environments we occupy. Therefore we must rely on mathematics to guide us in understanding how their existence influences what we observe in our world.

Many feel the most promising is called string theory, which attempts to define all of the observed properties of our universe in as many as ten dimensions.

However, as is pointed out on page 51 of Lee Smolin book "The Trouble with Physics" all attempts at unifying physics through extra dimensions suffer from the same problem. There are a few solutions that lead to the world we observe but there are many which do not. One has to set the initial conditions, which are found by observing our world to determine which solutions define what we observe. The use of this circular methodology means its validity is not based on its theoretical structure but on its flexibility.

In other words its validity is not based on connecting the observed properties of our environment to it but the randomly picking which the ones do the best job.

Einstein’s theories are very different in that they make specific predictions based on the existence of a single space-time environment that if found not to occur would invalidate it.

For example his theory tells us that light should bend as it passes by a massive object.

If this was not observed his theory would have to be discarded.

However 1919 Arthur Eddington lead an expedition to photograph the Total Eclipse of the Sun. The photographs revealed stars whose light had passed near sun had been bent exactly as Einstein had predicted. The experiment was repeated in 1922 with another eclipse with the same confirmation.

Additionally in past century since he proposed his theory there has not been any observations of our macroscopic universe that disagree with any of its predictions.

Even so this does not mean that we should assume that our universe is physically made up of four dimensional space-time because as with all multidimensional theories when Einstein derived the geometric properties of a space-time universe in terms of the constant velocity of light he also define another one with identical properties in terms of four *spatial* dimensions.

In other words by defining the geometric properties of space-time in terms of the constant velocity of light he provided a qualitative and quantitative means of redefining its time related properties in terms of only four *spatial* dimensions.

As was mentioned earlier the fact that light bends as it passes by massive objects doers not mean our universe is made up of four dimensional space-time because the symmetry of equations used to make that prediction also predicts one made up of only four *spatial* dimensions will do the same.

Therefore the fact that light bends as it passes by a mass cannot be used to eliminate that possibility.

However there is a experiment very similar to the one Arthur Eddington preformed that would resolve this ambiguity.

Einstein’s Theory of General Relativity tells that objects that create gravitational field cause time to "move" slower. However due to the symmetry of his equations one could also say that time slowing down results in the formation of a gravitational field. Therefore one must assume that a gravitational field must always be attractive because observations indicate that time only moves in one direction forward.

However the fact that one can use Einstein’s equations to qualitatively and quantitatively redefine the energy he associated with gravity in terms of four *spatial* dimensions is one bases for assuming as was done in the article “Defining energy?” Nov 27, 2007 that it can be derived in terms of a spatial displacement in a "surface" of a three-dimensional space manifold with respect to a fourth *spatial* dimension as well as one in a space-time dimension.

However unlike time which is observed to only move in one direction forward observations tell us that we can move in spatially in two directions up down backwards and forwards.

Therefore if the universe was made up of four *spatial* dimensions there should exist a form of mass that posses a negative gravitational potential.

One candidate for such a mass is antimatter. We know from observations that in it posses an opposite electrical charge than its matter counterpart. Therefore it is logical to assume that it posses a gravitational field that is oppositely directed from that of matter.

An experiment has be proposed that could determine if this is indeed true.

As describe in the New Scientist article "Antimatter mysteries 3: Does antimatter fall up?" Apr 29, 2009, it involves using uncharged particles to prevent electromagnetic forces from drowning out gravitational effects. It will first build highly unstable pairings of electrons and positrons, known as positronium, then excite them with lasers to prevent them annihilating too quickly. Clouds of antiprotons will rip these pairs apart, stealing their positrons to create neutral antihydrogen atoms.

Pulses of these anti-atoms shot horizontally through two grids of slits will create a fine pattern of impact and shadow on a detector screen. By measuring how the position of this pattern is displaced, the strength – and direction – of the gravitational force on antimatter can be measured.

In other words there is an experiment that could determine if our universe is physically composed of four dimensional space time or four *spatial* dimensions because as was mentioned earlier a universe physically composed of four dimensional space-time cannot support a negative gravitational potential while one made up of four spatial dimensions can.

Yet if found to be true it does not mean that Einstein’s theories are invalid because his theories and predictions were based on pure mathematics and as mentioned earlier a universe consisting of four dimensional space-time and four spatial dimensional are mathematically are equivalent in every respect.

However it would require us to rethink our understanding of the physical geometry of our universe and the causality of gravitational forces.

Later Jeff

Copyright 2015 Jeffrey O’Callaghan