In the field of physics, a very interesting debate has grown up around the material existence of the phenomenon of time. The time we humans perceive also coincides with the tendency towards the disorder of all things, something that inevitably grows over time, as we adopt the most probable sets of objects and disordered configurations.
Throughout the last 50 years, many physicists have emphasized that the main equations and mathematical functions oriented to describe the interactions of material bodies, electromagnetic waves -and even the atomic and subatomic particles themselves- have the same validity, whether it is considered that their actions and movements come from the past towards the future or from the future towards the past. Even in nuclear reactions between diverse particles, their diagrams -called Feynman-, which describe their collisions and interactions, have so much validity in any sense that they have been attributed to the flow of time.
The arrow of time already becomes evident when large quantities of particles, atoms, or molecules interact and are capable of participating in practically irreversible phenomena -such as the breaking of a porcelain cup- in which the inverse phenomenon, which would be spontaneously reconstructed, is never observed.
The time we humans perceive also coincides with the tendency towards the disorder of all things, something that inevitably grows over time, as we adopt the most probable sets of objects and disordered configurations.
So we perceive the passage of time as the effort of our organism to maintain an ordered and functional state, counteracting deterioration.
The non-existence of time as one of the fundamental phenomena to interpret the reality of the universe has been sustained by personalities such as Victor J. Stenger and Julian Babour for whom time would be more opinion of individuals than natural law.
But a reaction has emerged among some scientists and philosophers, in particular, Roberto Mangabeira Unger and Lee Smolin, who disagree deeply and go so far as to qualify time as the fundamental phenomenon of reality and existence; the evolution of the universe and its laws.
For these scientists, time not only possesses an objective existence but has lasted indefinitely since the most remote past... it will do so towards the future and does not depend on the existence of space and matter.
Unger and Smolin also question the existence of the so-called multiverse -a set of parallel universes-, which has been postulated by some theoretical physicists who also question string theory and its explanation of subatomic reality.
For this, they claim, of course, the fact that it is impossible to prove or falsify the conclusions of all these theories since no evidence of their existence can be shown. They criticize the fact that the only basis for these abstruse cosmological theories, which involve the coexistence of many additional spatial dimensions - many of them shrunk or tightly wound in themselves - is only that they can be mathematically modeled.
Indeed, no visible effects, either in the cosmos or on a subatomic scale, have been detected for these events to occur.
But what do Unger and Smolin propose in return? For them there are no parallel universes of any kind; but there are -in the remote past of our universe- ancestral universes, in which natural laws different from ours ruled, which have evolved to become the ones that rule us now.
The truth is that even though his proposal is interesting and plausible, there is no observable evidence that this is the case in the cosmos.
They criticize that most of the atomic and cosmological theories in vogue are based on mathematics -complex mathematical models that make viable the reality in which we subsist. But that, in no way, makes their proposal about the preeminence of time and the infinite succession of already disappeared universes that gave results to ours more viable.