Immanuel Kant taught us that space and time is necessary for human understanding. Einstein told us that time and space are inseparable, hence space-time.
Despite these insights it can be argued that we in the final analysis understand time as little as we understand gravity, another of Einstein’s favourites. We do not understand time, because we tend to think that time is measurable as a flow. We talk about time as something with a heartbeat, seconds, minutes, hours, years. Yet, time has no heartbeat, it is us imposing our heartbeat on time. We divide time in fragments, in seconds and minutes, because this is the only way we can understand the passing of time. But, of course, time does not progress according to Einsteinian physics, all time is there all the time in the spacetime structure. Every suggestion of continuity of time is highly questionable, as David Hume in a sense argued 150 years before Einstein, when he questioned continuity of experience in a logic that is not too dissimilar to the time concepts of modern physics.
It is in the human condition to think that time is an unwritten sheet of paper that the life of the universe will fill with scribble. And although Einstein has convinced us that time is not an unalterable quality, that time is relative, even Einstein assumed that time was predictably variable according to the laws of physics that he defined. But is it so?
Time is a dear companion, but one of which we know less than about tomatoes. For tomatoes we know about their inception, their end, their uses and non-uses. About time we might think that it is finite, but without beginning and end, if we believe Einstein’s spacetime structure – spacetime just exists. Yet, we do not know if our spacetime structure might be part of a much larger structure, we do not know about all the various permutations of time and spacetime that might exist in other universes, we do not know if in some contexts time might be infinite. In the many-worlds theory of Hugh Everett it is assumed that anything that is possible will be reality in some universe, and if one stretches that theory beyond its moorings in quantum mechanics one might argue that if endless time is possible then it will exist in at least some universe, and, perhaps, as a higher order reality.
We assume that time is colourless and odourless, in the sense that it has no qualitative quality. Time is what we make of it is our credo. We believe that we condition time, but that time does not condition us. But how we know that it is so? Is time necessarily a quality that we ingest and use, that we endow with quality, or is time also imposing quality on us. The Chinese talk about unrest under the heavens. That can be taken to mean that it is time that brings the unrest at that specific point, could mean that time does have colour and odour. Perhaps there are sometimes fortunate times for humankind, sometimes unfortunate times. Although it is sacrilege to say so, perhaps the relativity theory is too limitative.
Perhaps some universes are without time, or operates on different dimensions than time, dimensions we might not be able to understand given our evolutionary conditioning, and given that we do not even really understand time. In fact, our own universe might have started out as one without time, perhaps this was the starting point for the Big Bang – all reality compressed in one immensely dense mass. The Big Bang might have been caused by the addition of the dimension of time. Physicists talk about the Big Bang releasing tremendous energy, but given that the effects of energy are predicated on time, and that time might be predicated on energy, it is not so unlikely that our universe was originally timeless, and that the Big Bang was a function of the addition of time to our universe. Other universes might have had same starting point but might exist differently because another dimension than time might have been added to the immensely dense mass that was the starting point. And, marvelously, the same immensely dense mass that was the starting point for the Big Bang might have been the starting point for all those other universes featuring different dimensions than time and different permutations on time. This might be so, because according to quantum mechanics the mass at the time of the Big Bang would have been in superposition because more than one way ahead was possible. Every different dimension, every different permutation of time would be in superposition, and according to the many-worlds theory every such alternative would play out in its own universe, and each combination of dimensions in their own parallel universes in addition.
I hope I have convinced you that we know little about time, and nothing about its alternatives!