The question about the existence of time has caused the fiercest debates between scientists and philosophers. Strangely, both arrive at an open possibility that is a bit sinister for the practical purposes of our perception of reality; time does not exist. However, this hypothesis has no power over everyday life, but it would be conclusive evidence that physics and the way in which it describes reality still have important gaps.
A physical maze with no way out
During the last century, two main theories have been used to explain the Universe and its phenomena. On the one hand, there is the revolutionary theory of Albert Einstein, which at the time represented an abysmal advance in science; the Theory of General Relativity that explains the movement of bodies. On the other, we have the emerging quantum mechanics that explains the behavior of particles and their interactions in extremely small dimensions.
Both theories work optimally in their own right, the troublesome issue comes when trying to merge calculations from both theories. As suggested by the scientists themselves, both mathematical perspectives of reality seem not to be compatible and, on the contrary, would conflict. This is why it has been suggested that physics itself is in crisis, since if both theories were correct, then they would be capable of being unified to comprehensively explain all the behavior of the Universe.
Many physicists continue to explore new ways to explain reality, which means producing a new theory of quantum gravity that captures the extraordinary success of both theories on their own, but now unified into one. Only in this way could gravity be explained in dimensions as small as particles and, in this sense, offer a complete vision of the behavior of the Universe and its interactions.
Time in terms of quantum gravity
The search for a unified theory has not been easy at all, it is, in fact, a mathematical maze that seems to have no way out, at least not until now. Perhaps one of the best-known attempts to unify relativity and quantum mechanics is String Theory, which uses a model of up to 11 dimensions. Unfortunately so far it has not produced a significant advance and has not made clear predictions that can be tested through experiments to give it the necessary validity.
This is why during the 1980s and 1990s, physicists sought alternative paths to String Theory. One of the most prominent is Loop Quantum Gravity, which proposes the fabric of space-time is made up of a network of extremely small fragments called ‘loops’. However, it is precisely here where a significant change in the perception of time occurs, because for the theory to work, the concept of time must be completely eliminated.
Does time exist?
Suppose the theory of Loop Quantum Gravity turns out to be accurate in all its predictions, then would this mean that time does not exist? This is a question that really gets us into cognitive conflicts, since we base all our understanding of what surrounds us on the passage of time. However, this assertion is very complex and depends on what is meant by ‘exist’.
In simple words it could turn out that time does not really exist as a physical concept that appears in the mathematical equations to describe the behavior of the Universe. However, our perception of the wear and tear of bodies would continue to happen as we understand it today. That is to say, that time does not exist, does not mean that entropy has no power over reality and everything on this plane would continue to slip from order to chaos. Therefore, aging is not exactly a consequence of time, but rather of entropy, and nothing would change about it.
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