Passage of time is human perception. It is also how we order and make sense of numerous, many dimensional spatial changes that are occurring continuously. The experience comes from within the organism and is in part due to circadian rhythm controlled by the pituitary gland in response to light levels and in part interpretation of the sequence of spatial change experienced by that organism. Ageing is cumulative detrimental changes in the spatial configuration of the material components of the body including damage to the mitochondria the "energy production" units of the cells.
The tick of a clock gives a scale within 3D space that can be used to measure other spatial change. It is a man made construction that works together with human perception to give time a -seemingly- non spatial existence in the world. With a clock we can now see time passing second by second rather than having to rely on the astronomical changes, change in the earth relative to the sun, position of stars or moon in the sky etc. This takes us away from what time is to the universe.
There are changes with in 3D space that we can observe and measure. Distance A to B for example. Taking the 3 dimensions to be the only spatial dimensions that exist A to B is a fixed and unchanging. The position of A and the position of B do not change. The only other change that is occurring according to this viewpoint is change in time. However if distance A to B is measured on the earth's surface, then A to B is changing spatial position because of the earth's rotation about its axis, the orbit of the earth around the sun, procession of the solar system with in the galaxy and so on to bigger scales of change of position with in the material object universe. The cumulative effect of change at many scales, mostly circular motion is a change in -spatial- position. The object has not just moved A to B it has moved A to B' at the new universal position. When the object arrives at B' it is not in the same spatial position as B was, when the object left A. Some say prove it. Well do the celestial bodies of the universe move relative to each other or are they static? If it is assumed that they are moving as our observations show, then the passage of time for an object is a change in its absolute spatial position in the (object) universe. Nothing moves A to B even if we see and measure it doing so. It is only possible for that to be so if the whole universe is static. The 4th dimensional change is a universal spatial change that is generally unobserved and so is unaccounted for, except as passage of time. That is to say relative local spatial change within a particular frame of reference(3D vector) against overall universal change, encompassing changes over many many scales, planetary , solar system , galactic, galaxy cluster, object universal (scalar spatial change).
Then there is the question of where this dimension of spatial change can possibly exist if all of space is defined by the 3 spatial dimensions.There is only one place for it to be. Running from the exterior to the interior of every mass. Movement along this "scalar" spatial dimension is then able to account for gravity. The object does not move into itself with in a single 3D space but from one 3D space to the next in that orientation. The 4th dimension in the electromagnetic equations of maxwell become the same scalar spatial orientation.
It is the ordering of the change that brings in time. However only that which exists in atemporal now actually materially exists. If one considers that which did exist but no longer exists one has invented the past. Which has no physical existence in atemporal now only in the mind or in the calculation or as an image. If one predicts what will exist then one has created a hypothetical future. Which has no existence in atemporal now only in the mind or the calculation. The experienced present is a patchwork of time delayed data unique to each observer position.It is not the same as the existential reality of the material universe at atemporal now.Past, present and future belong to the image universe. Image and object are not the same thing!!!
Along the 4th dimension of the material object universe there is absolute space that has been passed through, is now occupied, and which will be passed through. Of course the spatial position an object occupied and other objects occupied prior to current atemporal now effects its current change. It is not existential past effecting the present but former objective now (the spatial arrangement and relative positions of all components of the material universe) universe having already influenced current objective now. Progression is from one universal configuration to the next, atemporal now to atemporal now. Atemporal now may seem to be in the future as it exists ahead of delayed transmission and interpretation of any data that can be formed into perception of that which exists.Can things exist before we are aware of them? Certainly. Research has shown that the fear response is detectable in humans before conscious awareness of any threatening stimulus. Immediate preparation of the organism for rapid response gives a survival advantage. The material organism can thus react before the conscious observer function of the organism has awareness of another material configuration presenting a threat. The conscious observer is thus always observing the past, a patchwork image of former material reality.
There is not a material copy of that which has already happened and the future is not already written and in material existence. There is no going back to the past, only back to space that has been passed through. There is no traveling to the future, only to space that has not yet been passed through. Aft space and afore space.It would require billions of universes worth of matter and energy for all of those temporal copy universes to exist. They are fantasy realms imo nothing more. I do not assume my reflection in the mirror to be a real independently existing person, even though I see it clearly.It is an image, a trick of the light.
The image of past events that are seen are just that- images created from the delayed transmission of photons. The material object universe is not the same as the image universe. The material object universe can be described by 4 dimensions, 3 vector spatial one scalar spatial. The image universe can be described by 4 dimensions. 3 vector spatial and one time. The image universe THE UNIVERSE is an image!!! The material object universe that we can not observe is the material object. How can it be said to exist if it can not be observed? There has to be an object to create an image. We could not see the image that we see now if there had not been an object universe. We could not see the 8 minute delayed image of the sun if there was not an object sun existing in atemporal Now. Einstein's work has to do with the -appearance of things- to an observer. Newtons work is to do with the existential matter of the universe. Perhaps too much importance has been given to the appearance of things and erroneous interpretations of the meaning of observation have been made.
At any distance at all from the observer there is time delay in information transfer and the image is non contemporaneous with the observer. The greater the distance the greater the discrepancy. We therefore operate within the image our minds create from a patchwork of time distorted information. That is not the material object reality. That is important.
Considering an eternal material universe one must also consider entropy. By chance, under the influence of forces and organic organization particles come to positions that are more stable than a change in that position and so structure and organization occur. However though matter can come together into structures these too can be broken down. Bodies decay, rocks erode, stars explode.On a universal scale entropy and organization are both ongoing processes.A dynamic equilibrium.I consider it more likely that there is continuous recycling of the universe rather than cataclysmic creation and destruction events of the entire universe simultaneously. The big bang scenario has arisen from the assumption of an expanding universe which is in turn based upon interpretation of red shift data, which may be incorrect. As it takes into account only 3 spatial dimensions of change.
Like a river deposits silt and erodes silt, carving out meanders. The sea deposits sand to build beaches, but also erodes beaches and cliffs.The universe builds stars, planets and lifeforms but also disintegrates stars, planets and lifeforms. Energy is stored in structures and energy is released. Matter is stored in structures and is released to build new structures. Energy is never destroyed. It is eternal if one thinks in terms of time.It is merely atemporal comprising only ongoing spatial change as in material reality everything exists only in space, at an ever changing spatial position. The time dimension is the dimension of the fantasy realms, past , present and future created by light images. The scalar spatial dimension is the dimension of absolute change of the material object universe. Do physical processes occur within the image of the universe or within the material object universe? I say within the object universe.