Some things are very difficult to imagine. They say, "one death is a tragedy, but a million deaths is a statistic"; this is because we can imagine one death but we don't have the computational power to imagine the social breadth of a million deaths. It's too wide. Some things are too small, too restricted, to imagine. One such thing is a one-dimensional object. So I'm going to skip the awkward and mind-boggling (lack of) opportunity presented by such an object, and perhaps wait out to stumble across a good description of 1D physics in a theoretical maths or theoretical physics book. Until then, their kind of reality escapes me. Moving swiftly on (not that 1D objects can move), let's start with two-dimensional objects.
It is easy to think we can imagine two-dimensional objects, but in reality we have never seen one. A two-dimensional object has only two dimensions, meaning, it has a width and a breadth but no depth. In theory, it has either no depth so it does not exist, or, it has a kind of infinite depth, meaning that every two-dimensional object would project from one side of the universe to the other, like a pipe running through a room from one side to the other. It can be mapped in terms of height-above-the-floor and distance-from-the-north-wall, but, it is not logical to say you know its length. That's how two-dimensional objects are: they don't quite fit realistically into a 3D system.
All 2D objects we think we have seen are visual tricks. The most famous one that tricked ancient humanity, was the sky. Thousands of years ago, the sky was described as flat; a ceiling. Because it is far away we cannot perceive depth in it. Just like the sun looks 2D, because it is so far away that all the rays of light coming from it appear to us to be parallel. There are other types of fake 2D objects such as paintings and electronic screens. These so-called 2D images are really 3D because they all have a measurable depth, and are comprised of 3D objects such as paint molecules, glass particles in screens and via picture elements (pixels) in cathode ray tubes (CRT) monitors. Because they are constituted from very thin 3D objects we simply call them 2D. Some theoretical physicists such as String Theory enthusiasts, do hold that two-dimensional objects can exist but they exhibit very extreme behaviours and properties.
If we can see that 2D objects cannot realistically exist in a 3D world, then it probably holds that 3D objects cannot exist in a 4D world. But before moving on to that exciting discussion, I want to describe how a 3D object could exist in a 2D world, in ways that we can imagine.
If we do have a 2D object, such as a picture, then we can turn it into a 3D object via a simple trick. If we make an exact copy of the 2D painting and change it slightly, and put them behind each other and repeat this 100 times, the result apparently turns 2D into 3D. Every school child knows this. If you draw a stick man in the bottom corner of a notebook, and a slightly different one on the next page in the same relative location, a school child can then bend the corner of the notebook, flick through all the pages and see each 2D drawing in quick succession. This creates an illusion of a 2D stick man moving. It is almost as if the 2D drawing has gained a third dimension of movement.
The child, who exists one dimension "above" the drawing, created the stickman's past and future (even if it is presently half way through its flickering existence). The stickman has no way of perceiving or inferring the existence of dimensions other than its native two (unless the stickman developed complex maths, as we have). It exists in ignorance of "higher" dimensions. Higher means dimensions that are not native to the theorized 2D object.
Moving on to 3D objects. Three dimensional objects can also be put into a series of slides, each one slightly different. By viewing these slides one at a time, it looks like objects change over time. By definition, by philosophy, by complex dimensional mathematics and through physics, we arrive at the common popular refrain that "time is the fourth dimension". And so it is. A 2D object repeated on every page of a child's notebook has become an object with three different dimensions of movement, and a 3D object that changes over time exists across four dimensions.
We saw before that a 2D object cannot exist in 3D space. Likewise, a 3D object cannot exist in 4D space. Everything must be four dimensional. And we know this is true. Every 3D object such as a piece of material, changes over time. It changes its position in space and time, and its constitution undergoes many rapid quantum changes. Each moment-in-time describes one slide of its 3D existence, in total, making a 4D object. With every passage of every nanosecond, every object has changed its position in time. Each frame is different. We experience this march of the 3D frames to be what we call time, although in mathematics the maths to translate a 2D object into a 3D one follows exactly the same logic as trasfering a 3D one into a 4D one. By convention we call time the fourth dimension, although it is misleading to give dimensions names or numbers as if there was a hierarchy.
Because we know from experience that the universe has at least four dimensions, it may be true that everything changes over time. But, as we saw a 2D object exist in 3D (as a pipe through a room), what if there were objects that did not change in time? They would be experienced as (for example) a box that never moved. This means, its absolute location never changes. Nothing about it would ever change. It would exist eternally and infinitely in exactly the same state; if it changed over time, our cube would have proved itself to be existing in four dimensions, not three. To stop existing "under" four dimensions is to never change in three, just like our 2D pipe never changes in one of its dimensions: its cross section is exactly the same in every frame. Here we have described something that 'never changes', which exists 'outside of time'. (These terms have different implications, as we'll see later.) Such an object presents physical problems; as when it reflects light then it has exerted a force and used energy (therefore it has changed), but if it does not interact in any way then it is invisible and as if it does not exist. Forgetting these problems, we now move on to the theological debate that we have been leading up to.
There is another sense in which things exist "outside of time" other than the sense that something that exists only in 3D and not 4D. This is something that exists "outside" of the entire four-dimensional construct. If a 2D object existed in the 'wrong' dimension, perhaps a 3D being could pick it up, turn it around and examine it. It wouldn't be able to change it, once discovering it, because if it is only a 2D object then it doesn't change in any other dimension. The same goes for 3D objects.
If a Human creates a sculpture, we can consider this (wrongly) to be a 3D object that doesn't change over time (after having been created, that is). The sculptor can examine the object, rotate it and examine every 2D 'frame' (slice) that makes up its 3D totality. The Human being, the four-dimensional being, exists 'outside' of the 3D system. It can see where the model starts and ends. If there was a crack in the clay, the Human could look at the crack 'frame by frame' and see where it starts, trace its path, and see where it ends up. The creator of the model exists 'outside' of it. This becomes a very important distinction when we move to consider 4D 'real' objects, such as the Universe itself.
Let's simplify the universe to our own experience and describe it as a four-dimensional entity. Some big bang models predict up to nine dimensions, but I have the same problem-of-imagination that I had with one-dimensional objects, so I'm going to ignore all dimensions but the four "real" ones.
If a God created the 4D Universe like our Human above created his 3D model, then, such a creature could take the universe and examine everything that happens in it, frame-by-frame. If a persons' life starts at time A and ends at time B, then, like the crack in the 3D model, the 'outside' observer can view a persons' whole life, from beginning to end, in one glance. By taking the Universe as a 4D object you get to see all history (i.e., all slides of the 3D progression) from the first frame of time to the last.
Being outside of time provides a being with an apparently omniscient knowledge of everything that will happen, and everything that has happened. Obviously our discussion has become very metaphysical, and we are now talking specifically about the Western creator-god envisaged by the Greeks and inherited by all of our monotheistic world religions.
To exist outside of time has another implication. If you existed outside of time, it would mean that there are no 'frames' of you that change snapshot-by-snapshot. If you are not part of time, and changing, viewing it from within, then you are outside of time viewing everything from the outside.
“I the LORD do not change.”
Without change-over-time, any eternal being is immutable. There are no frames, no changes over time. In other words: No progress, no retreat, no changes of mind, no learning, no psychology, no changing of emotions and no active thought. A being outside of time exists as one instant, one snapshot only (like our 2D painting in a 3D world; constant). Emotions, thought, planning, progress and all those other things require change over time. Knowledge, also, would be absolute.
Nothing new could be learned because everything that is real and true exists in the 4D object that the being outside-of-time sees all at once. A creator-god who created the universe would exist in a very strange state. This being would exist, forever, viewing the universe that it created as a single 4D object that itself doesn't change over time. All of reality, everything, is 'there', not 'happening' now, but merely existing in reality. Nothing in the world could ever surprise an eternal creator, just like the stickman will never do anything that the child hasn't already seen.
This explanation, going through all the dimensions, truly gives an idea of how a being could indeed be all-knowing about everything that goes on in the universe, but such a being lives in a sad state of eternal immutability. This ties in with one other commonly-cited feature of God: its perfection. If a being is perfect, it cannot change. God's all-knowing nature, the eternality of its existence outside of time, its status as an outside creator of the universe and finally its status as a perfect being, each predict that God is unchanging. William James calls this the lack of 'potential' for God:
“This absence of all potentiality in God obliges Him to be immutable. [...] Were there anything potential about Him, He would either lose or gain by its actualization, and either loss or gain would contradict his perfection. He cannot, therefore, change.”
Traditionally the Creator of Judaism, Christianity and Islam and many other religions, is a creator that is emotional, creative, moral, judgemental and personable. Nearly all monotheistic religious books contain descriptions of God portraying emotions that require the creator to be subject to time, not outside of it. For example in Genesis, God is found 'looking' for Adam and Eve; on other occasions, a Human being changes God's mind through the use of a rational argument in one instance, and through the use of a blood ritual in another occasion. The creator of time cannot change its mind - nor can a perfect being. To change is to be subject to time, and to change implies that what comes after was better than before, which would contradict God's perfection.
“By employing mathematics as a language, science can describe situations which are completely beyond the power of human beings to imagine. Indeed, most of modern physics falls into this category. [...] It may be logically impossible for anyone to be able to correctly visualize certain physical systems, such as atoms, because they contain features that simply do not exist in the world of our experience. [...] Failure of the human imagination to grasp certain crucial features of reality is a warning that we cannot expect to base great religious truths (such as the nature of the creation) on simple-minded ideas of space, time and matter.”
Despite the contents of parts of scripture, these conclusions were naturally reached by some of the leading historical Christian theologians. St Thomas Aquinas in the second book of his Summae Theologiae concludes that god cannot change itself, cannot be weary, or forget, or repent, or be angry or sad. It cannot undo the past, St Aquinas says, or make itself not exist. This is all because all these things are temporal events that require God to be subject to time itself; but as time is a dimension created by god, God is above and outside it.3
The result, in my opinion, is that if a God exists that is not subject to time like the rest of us, then, such a being is immeasurably cold and emotionless; much more like a robot than the God that many people wish exists. In fact, I would say that such a God verges on being self-contradictory. It's more of a principle, unconscious and non-thinking. That is, of course, if you believe in God.
The Bible (NIV). The NIV is the best translation for accuracy whilst maintaining readability. Multiple authors, a compendium of multiple previously published books. I prefer to take quotes from the NIV but where I quote the Bible en masse I must quote from the KJV because it is not copyrighted, whilst the NIV is. [Book Review]
God And The New Physics (1984). Penguin 2006 edition. Davies is a Professor in theoretical physics who has published ground-breaking research.In chapter 9, "Time", Davies presents some interesting and thought-provoking material on these topics.
The Varieties of Religious Experience (1902). From the Gifford Lectures delivered at Edinburgh 1901-1902, first Edition printed 1960. Quotes from fifth edition, 1971, Collins. [Book Review]
Russell, Bertrand. (1872-1970)
History of Western Philosophy (1946). Quotes from 2000 edition published by Routledge, London, UK.