Philosophical View on Time
A Few Introductory Concepts
Translation is a type of movement that is a deviation of position with respect to some initial condition in a constant direction. For example, the initial position (X1) of an object is 2X. If the object experiences translational motion, it's next position (X2) may be 5X. There are three spatially extent dimensions that we are aware of. Translational motion is a simple rigid motion in any of those directions. I will call these dimensions X, Y, and Z for length, width and height. There are other types of movement that are possible, such as rotation and vibration. These are more complex than translation, but the important thing to note is, at least in traditional physics, all motion is some combination of movement within X, Y or Z.
A Brief History of Space and Time
Ever since incredible individuals like Albert Einstein and Hermann Minkowski, people have merged the temporal dimension with the three spatial dimensions. This merger is called space-time. The reason behind the merger is that relativity shows a dynamic relationship between space and time, as opposed to the classical view that time was completely independent. Before relativity, time was viewed as a one-way trip at a constant velocity. Now we are aware that the rate at which time "flows" is effected by properties in the spatial dimensions, like mass and velocity. This phenomena, known as time dilation, is important to consider in a lot of modern contexts, perhaps most famously in GPS technology. Theory even suggests that it is possible to have retrograde temporal motion, which means to go backwards through time. Even traversing time in reverse is still a translational movement; it just means time is no longer one-way. If other types of motion are possible in the spatial dimensions, why cannot rotation, vibration, or other undefined complex types of motion be possible with the time dimension?
Non-translational motion in the time dimension could cause an array of phenomena. Perhaps it is responsible for why people perceive time differently based from their activity level. As the saying goes, "time flies when you are having fun." Time dilation already proves that the spatial dimensions effect the temporal one. Considering that, it is no great stretch to presume that the spatial dimensions may cause the temporal one to experience non-translational motion. There is also no reason to assume that time has always proceeded at precisely the same rate.
Possible Effects of the Big Bang on Dimensions
Relativity has shown that mass has an effect on the rate of the passage of time, as does velocity. Prior to the big bang, the universal singularity had an infinite mass. Thus it would experience no time. There are many theories about the big bang, and what happened immediately afterwards. In all probability, we will never know. Perhaps tachyons, particles that travel faster than the speed of light in a vacuum, sped outwards, essentially pulling the fabric of the universe with them. At any rate, there could not be dimensions (including time) until mass/density was less than infinite and the velocity was less than the speed of light. Infinite mass and superluminal velocity would violate the Lorentz invariance and cause Lorentz contractions, making any dimension too small to exist.
Why Time Cannot be Uniform
Since there was a charge-parity violation and density anomalies, the amount of matter is not uniform throughout the universe. Since matter effects time, then time is likewise not uniform across the universe. Fundamentally, every point in space-time would experience time at its own rate. Every local gauge symmetry or inertial reference frame may be continuously decomposed down to specific points. Since most objects are on a macro scale, from one point to the next the mass and velocity is unlikely to change appreciably. Therefore the translational movement for adjacent points of space-time is nearly constant, except in extreme scales of time. Consider a main sequence star, which may last for billions of years. It's mass and velocity are fairly stable across even that incredible length of time. Another example is interstellar space. There is comparatively little, although not nothing, there across almost any timescale. However, if it is true that effects in the spatial dimensions generate temporal motion of types other than translation, only the translational motion of time may be regarded as nearly constant. The opposite is true for the spacial dimensions. On a fundamental basis, the rotation and velocity is unlikely to change, while the translation is very likely to. This is exemplified by zero point energy, in which the translational motion stops, but the rotation and vibration continue (at minimum) in order to provide stability. This minimum amount of vibrational and rotational motion may be regarded as the near constant for the dimensions of space.
Some Closing Comments
If the spatial dimensions have effects of the temporal dimension, there seems no reason to assume that the opposite is not true. Of course, people age over time, and the effect is obvious. That has been tentatively explained by the shortening of telomeres, the cumulative assaults hypothesis, and various other theories. Does it really have anything to do with time effecting matter, or is it that, as time passes, these events occur? It is fair to say that space is usually thought of as being made up of, or at least containing particles. Perhaps it is for this reason that space, or the particles it contains, is able to effect time. What about time though? Is it possible for a dimension to contain no particles? To answer these questions, and more, I have some additional theories.