You may or may not know the name of Fred Hoyle. He was the man who originated the term 'Big Bang', though with English north-country level-headedness he did not believe much in the existence of the supposed event. However, said event gives us a reference point. It occurred, they say, 13 8 billion years ago, give or take a few hundred million.
So suppose you are at 'Big Bang' plus a billion years. What do you see? Well, a big flash-bang, according to those who say they know, and a billion years of 'past' things. Now look onward. What do you see? Why, nothing of course, because you and your senses with which you see such things as 'the future', can see nothing in that direction.
Now fast-forward to 'today'. What do you see? !3.8 billion years of visible evidence of 'the past'. Now look onward. What do you see? Nothing. Why not? I told you: because you, and the senses by which you experience such things are not sufficiently advanced in space to experience anything in that direction. However, as we see from looking back, all the inscrutable 'future' of the past is all here. Similarly, all the things of 'the future' are already here, requiring only the presence of senses in 'the future' to experience them. So it should now be obvious that all Universe exists simultaneously and is complete, only requiring a presence of senses and sense to appreciate it. Or do you prefer to believe that all 13.8 billion years of evidence are fiction, and did not really happen without human intervention? Well, it did happen, as we can see, in a single action of the infallible process of cause and effect, existing, as we can also now see, complete and simultaneous.
For some reason that is not entirely understood, 'scientists' exempt themselves from the universal equation when they are considering the nature of things. However, despite their vehemence, we are not 'put here' separately to evaluate and perhaps somehow to approve Universe: We are an inextricable part of its process of completion. Universe enacts us, simultaneous with the other microbes and such things as the existence of mud.
So ask them when 'the present' is, and they will probably refer to their 'lifetime', but the reality is much more specific than that. Consider this: you cannot do anything last year or yesterday or even a second ago, the only point at which you can react or intervene is 'now' and thenceforward for a second or so, as you cannot guarantee even being alive for longer, so you can only act 'now'. So when is 'now'?
Living creatures have evolved so that they advance in bio-chemical sequence step by step by step, consciousness first as enabled by our senses, and adapting to varying circumstances as our genetic prescription permits and so surviving or being eliminated. That is obvious enough.
But also consider this: as each second passes, as an integral and inextricable part of the universal process you and your body act out a second of 'life', you and the planetary surface on which you live progress by half a mile, the planet itself travels twenty miles or so on its orbit of the nearest star we call our sun, the sun moves a couple of hundred miles on its course around the rotating galaxy, and the galaxy moves two or three hundred miles towards its distant appointment with Andromeda. That is all per second. However, we merely experience 'a second' of what our senses present to us as 'time', which otherwise does not exist, and it is worth noting that our experience of the duration of a second itself varies from infancy to old age by a factor of ten. In old age our materials and the senses that they provide have moved through space by the total accumulated distance, though it seems trivial in retrospect.
But we can see that things of 'the past' still exist. They do not cease to exist simply because we are no longer 'there' to experience them. And in the same way that they still exist, so also already do the things of the future, as we can ascertain by merely looking back on what previously was the inscrutable 'future'. However, fixed with the progressive position predicated by the inevitable progression of our metabolic molecular process, we are not sufficiently advanced in space to witness those things. So it should now be obvious that Universe is all here, but that we can see it only from our 'now' in the little span of our existence as part of its process of completion, and see it only as incomplete and -- because of the specifics of our bio-chemical senses -- can see it only as being 'in action', which obviously is a severely limited view.
Creatures of the future will see such things that are to be seen from their 'present' place in space, but we will not. However, as we have seen before, all things of the future already exist, requiring only the presence of senses and sense to experience them.
So Universe can be seen both sublimely simple in its completion, or incomprehensibly complex in its composition.
Apart from other misconception, take 'chaos' for example. 'Chaos', rather than an attempt to offend our sense of tidiness, is really universal perfect order.
So now, for fun, fast-forward as far as you can go. Look back. What have you? Universe, complete with space-extension with distance, consequent 'redshift' of light emitted by a receding body, and multi-dimensions described and called whatever you decide to ascribe, finite if physical, infinite if only a concept.
Let there be Universe. And Universe is.
Look onward. What do you see? I haven't the slightest idea, but I imagine you will try to tell me.
Mistify this concept all you want with algebra if it brings you joy to mystify but, despite all evidence to the contrary, this is not really necessary. 'Mysteries' are to be resolved.