A Scientific View
What is time? What is space? Those seem to be reasonable questions to ask of science, but what one gets back from the scientific community in response is anything but clear and unambiguous. There appear to be at least two competing camps, one of which believes time and space to be an illusion while the other insists that both are real and fundamental aspects of nature. There appears to be a general sense of confusion spread evenly across the competing views.
In a Scientific American article entitled A Hole at the Heart of Physics from A Question of Time: The Ultimate Paradox (Scientific American Editors (2012-11-30) by George Musser the author presents the fundamental disagreement clearly enough as an old metaphysical question:
Do space and time exist independently of stars, galaxies and their other contents (a position known as substantivalism), or are they merely an artificial device to describe how physical objects are related (relationism)?
All the discussions offered by scientists, mathematicians (and philosophers!) throughout this collection of previous Scientific American articles are either of a philosophical, mathematical or metaphysical nature. Being uncertain as to the nature of time (and space) is no hindrance to fanciful speculation. Apparently it is easy to write articles with titles like How to Build a Time Machine and Could Time End? as long as you are not really certain what it is you’re talking about.
The real question posed by this Scientific American compendium though is why there is so little science in it. Mathematics, metaphysics and philosophy may not be able to conclusively answer the question of whether space and time exist independently of the means by which we measure them, but science certainly can.
Succinctly stated, there is no empirical evidence whatsoever to support the view that time and space are independent entities. Therefore, scientifically speaking time and space can only be aspects or characteristics of the means of measurement.
But what does that mean? It means that time is a characteristic of matter because it is only by material processes that we measure time. All clocks, whether natural or man-made consist of repetitive physical processes which are used as standards to measure the rate of other physical processes.
Matter is three dimensional and time is a reification of some general properties of matter. This reified entity, time, then gets transposed by mathematical and philosophical considerations into a fourth dimension. There is no scientific basis for either the reification or the transposition. Time as an independent entity does not exist.
All of the things that seem peculiar about time as a “dimension” seem perfectly normal when thought of in regard to material processes. The arrow of time simply becomes the Second Law of Thermodynamics – time does not have a direction, physical processes do. The past can be remembered but the future cannot simply translates to the trivial notion that we can remember processes that have taken place but not processes that haven’t taken place. We can know the scores of yesterday’s ball games but not tomorrow’s.
Space is another matter entirely, or more properly, space is the reification of another form of matter – energy. As with time, the scientific case is straightforward. There is no empirical evidence of a space that is empty of both matter and energy. In fact a simple observation made possible by modern astronomical observatories is that in whichever direction we look we find galaxies out to vast distances. There are many different types of these galaxies but they all exhibit a common property. They are all radiating electromagnetic energy omnidirectionally.
This means that everywhere we look and do not see matter there is electromagnetic energy and of course, the act of ‘looking’ entails the direct detection of electromagnetic radiation. We find no evidence of an independent “space”, therefore scientifically speaking space, like time, has no existence apart from the electromagnetic energy that, observation tells us, exists everywhere matter does not. What we call space cannot be empty. It is electromagnetic radiation.
Does this mean we should discard the very notions of time and space? Of course not, they are very useful when properly understood as being descriptive of very real characteristics of matter and energy. There are just no such things as flowing time and an empty space with physical properties, in and of themselves.
All we are left with then are matter and energy, the two fundamental and irreducible entities from which physical reality is woven. Matter is composed of energy and energy is created by matter. They are the warp and woof of the cosmos. Science to date has only grappled with the second part of that dual relationship. We have some understanding of the ways in which matter can release energy; we have no real grasp of the ongoing reciprocal process that creates matter from energy.
There is no such thing as an empty space, i.e. a space without field. Space-time does not claim existence on its own, but only as a structural quality of the field. —Albert Einstein
For Newton, gravity was a force that acted instantaneously at a distance. The modern conception of General Relativity identifies gravity with the curvature of space by matter. Since the foregoing section dismisses the notion that space has any existence independent of the electromagnetic energy by which we observe it, how then can we account for gravity?
The Island Universe Theory recognizes the existence of two distinct types of reference frames, the 3-dimensional reference frame of matter and the 4-dimensional reference frame of electromagnetic energy. It is the interaction between these states, matter and energy, that produces the gravitational effect. 3-dimensional matter presents a dimensional vacuum or drain to electromagnetic energy, drawing it in and curving it in just the manner we observe. So matter is a kind of hole in the 4-dimensional dis-continuum (because it is discrete, being composed of quanta) of electromagnetic energy that separates material objects. It is the propensity for electromagnetic energy to fall into those material holes or drains that accounts for the phenomenon we label gravity. In this view then, two material objects do not attract each other; they attract and absorb the electromagnetic energy that separates them, creating the appearance of a force drawing them together.
The recognition of the two distinct reference frames of matter and energy thus accounts for gravity itself as well as providing a gravitational explanation for the cosmological redshift.