I began studying physics in undergraduate school in the late seventies, and I have long been fascinated by the most famous scientific theory of all time --- Einstein's theory of relativity. It essentially says that the speed of light is the only thing in the universe that never changes. This means that, if someone stands on the earth and shoots a flashlight beam in any direction away from the earth's surface, while another person chases after the beam with a speed of 99 percent the speed of light, then the second person cannot gain on the beam at all. In fact, the second person will measure the beam as moving away from himself at the full speed of light, despite the fact that he is moving faster than the flashlight by 99 percent of the light beam's speed!
Since speed is the distance traveled in space, divided by the time taken, one of the consequences of this incredible finding, is that, from the vantage point of the stationery individual, the 'space' of the second person must contract or 'bunch up,' while his 'time' must dilate or 'stretch out,' both being required by the much verified fact that the same light beam moves past both observers at the same speed of light. (However, the moving individual knows nothing of any shift of his or her space and time, the space and time in his or her frame of reference remains perfectly normal. It is only from the stationery observer's point of view that the moving observer's space and time are shifted). This means that all distance and time measurements made by the moving observer must yield shorter values than the same measurements made by the stationery observer. This must be, so that mathematically, the quotient, distance divided by time, yields the same value, namely, the scientifically verified, constant value of the speed of light. This means that contrary to our everyday experience, neither space nor time are absolute in the physical world that we know within our human perception. Rather both space and time are completely relative and variable with respect to this world; they both vary with the speed of the observer making the space and time measurements. A meter stick is correctly measured to be less than a meter, when the person doing the measuring is moving past the stick at speeds comparable to the speed of light. Likewise, an event measured by a stationery observer at the location of some event, to have a five second duration, will be measured to occur in a shorter period of time by an observer moving past the event at high speed. This relativity of time and space is always present, even at very low speeds. However, in our daily life, we do not see this variation because it is not noticeable to our maximum capacity of measurement, (the shift is smaller than our resolution capability) until the relative difference in speeds becomes very large.
The important point for our current purpose is simply that time is not absolute, but relative, with respect to our own 'humanly perceived' world. It can therefore be said that time is not completely real in our physical world.
If we then postulate an ultimate or Absolute Reality that our physical
world is relative to, or derived from, we obviously observe that, from
the perspective of this Absolute Reality, the physical world is less
real than Itself. Next, we pose the question: Then what is the relationship of time to this Absolute Reality?
The answer is that, since time is not even completely real, here,
within our perception of the physical world, then when we view time
from the level of absolute Reality, it follows that it must be even
less real. However, what is the meaning of 'less real than relative,'
or 'relative to relative?' After some thought, I was convinced that
anything 'less real than relative' must be nothing at all. In other
words, from the position of Absolute or True Reality, time is a
complete illusion! Another way to say it, is in the form of the
Time is relative to the physical world.
But, the physical world is relative to the Absolute World.
Therefore, time is relative to (something relative to) the Absolute world.
But the definition of the term, 'relative' only has meaning in the sense of 'relative to some absolute.
This means that the double term 'relative...relative' above, says that time has no meaning, or, has the meaning that time is nothing.
Time is therefore an illusion with respect to absolute Reality.
If there exists an Absolute Reality, then time is an illusion.