< See chapter 5 | Continue to chapter 7 > | See all chaptersThe reversibility of time has been a subject of extensive discussions in science and philosophy.
The question is, why, despite the fact that all basic physical laws are time-symmetrical (i.e., allow the reverse flow of time), in practice time flows only in one direction – i.e., it is asymmetrical.
Indeed, the laws of Newtonian mechanics, Einstein's Theory of Relativity and Maxwell's electromagnetic field theory are all time-symmetrical.
Quantum mechanics introduces CPT symmetry, where C is the 'particle–antiparticle' charge conjugation, P is parity transformation and T is time reversal. The CPT theorem confirmed by Lüders and Pauli requires that CPT symmetries must be observed.
At present, experimentation has confirmed that the process of β-decay is accompanied by P (parity) irregularities even while the CP symmetry is observed. Experiments with K mesons demonstrated breaches in CP symmetry, which implies a consequent breach of T symmetry.
One of Richard Feynman's theories postulates that an electron is equivalent to a positron moving backward in time. However, this has not been confirmed experimentally.
To this day the Second Law of Thermodynamics, which is time-asymmetrical, remains the only viable explanation for time asymmetry. There is also the Past Hypothesis implying extremely low entropy at the inception of the Universe. Thus, due to the Second Law of Thermodynamics, as the Universe evolves, entropy increases, determining the direction of the arrow of time.
Ludwig Boltzmann, the creator of statistical mechanics, believed that the direction of the flow of time is determined by the local gradient of entropy in the same way as upward and downward directions are determined by the local gradient of gravity.
These explanations have been criticized by the scientific community for the following reasons:
1) The Second Law of Thermodynamics is not deduced from the basic laws of physics. It is accepted as an axiom.
2) The Second Law of Thermodynamics is emergent by nature. This implies that the concept of entropy does not apply to individual particles, and the laws directing their movement are time-symmetrical.
The concept of entropy arises only for ensembles of particles, and there is no way to define how many particles are necessary to create such an ensemble.
3) The Second Law of Thermodynamics is statistical. The Poincare Recurrence Theorem allows a continuous-state system to return to its initial state after a sufficiently long period of time.
4) While the concept of entropy is analytically determined for systems in a state of equilibrium, our Universe is a dynamic non-equilibrium system.
5) The Past Hypothesis, the idea that our Universe had an extremely low level of entropy in its initial state, has not been proven.
6) It is not clear whether we can even talk about such a concept as the entropy of the Universe.
7) The fact that the entropy of the Universe has grown in the course of its evolution has not been proven since the entropy of the gravitational field must be considered in addition to the entropy of matter.
8) It has not been confirmed that our Universe is a closed system.
9) Determination of entropy relies on the knowledge and information available to us – that is, it is subjective and anthropomorphic. Carlo Rovelli and Edwin James, renowned theoretical physicists, have written about it. If we are talking about the entropy of the Universe, who defines it?
There is an interesting remark in the book At Home in the Universe written by one of the most prominent theoretical physicists of the 20th century, John Archibald Wheeler. He writes, 'Thermodynamics as we know it, is based on the random movement of billions of molecules. Ask a molecule what it thinks about the second law of thermodynamics, and it will laugh at you. Nevertheless, collectively, these molecules support the Second Law of thermodynamics.'
Before expressing the perspective of the Kabbalah of Information on this topic, we need to define reversibility of time. There are two approaches to this issue, both of which were considered in the article Time Reversal by Bryan and Roberts.
The first approach assumes that in all equations of basic laws, the time parameter T can transform into –T. Other physical parameters — speed, momentum and characteristics of fields — can change accordingly.
The second approach suggested by Albert and Callender is known as the Pancake Model. According to it, the order of the states of the system is time-reversible, whereas these instantaneous states themselves are invariable.
The perspective of the Kabbalah of Information is that all of Creation is a single informational space, the existence of which is supported by informational pulses, which are absolute. At the same time, our Universe is just a part of Creation; consequently, it is not a closed system. Each pulse records a certain informational state of the entire Creation that remains in its the memory. The evolution of Creation can thus be represented as a sequence of informational states recorded by pulses in its the memory.
The position of the Kabbalah of Information is that we can only consider the reversibility of time for the whole of Creation in the framework of informational pulsation (which is a position close to the Pancake Model).
Given that informational states are locked in pulses and cannot be changed, moving back in time would mean getting into a locked informational state, losing freedom of choice, stopping the pulses and thus obliterating Creation.
Hence, the position of the Kabbalah of Information is that the reverse flow of time is impossible. Time is irreversible. Another very important conclusion is that irreversibility of time is not a consequence of the Second Law of Thermodynamics. On the contrary, the Second Law of Thermodynamics is a consequence of the irreversibility of time.< See chapter 5 | Continue to chapter 7 > | See all chapters