The existing theories of time can be safely divided into those that admit travel into the past and deny this possibility. Hypotheses that allow time reversibility must necessarily contain an explanation of the “grandfather paradox”. Being the main argument of irreversible theories, the paradox is that a person who has fallen into the past can kill his grandfather and, in fact, must cease to exist.
The scientific analogue of this paradox is the irreversibility of the increase in the entropy values of any thermodynamic process.
In several previous articles, we showed how Henri Poincaré and Grigory Perelman proved mathematically the cyclical nature of thermodynamic processes ("Grigory Perelman proved the possibility of traveling to the past?")
And at the end of this article I will explain my point of view on the problem of going back to the past. But first, consider the theory of branching time.
In most science fiction writings, authors adopt a viewpoint similar to physicist Hugh Everett's interpretation of the quantum double-slit experiment. At the moment of choosing one of the two possible measurement results, the observer moves to one or another slice of the simultaneously existing Multiverse, leaving other options for choice to exist in an unmanifested form.
The famous Schrödinger's cat, existing simultaneously in two Universes, can be alive in one and dead in the other branch of time.
Not all physicists adhere to this interpretation of quantum experiments. But differences of views in science are no longer news since the presentation of the Copenhagen version of the explanation of quantum experiments, which is supported by less than half of modern physicists.
Promotional video:
Shroedinger `s cat.
Making a choice, every second we sweep aside many world lines of development. As a "good" grandson, killing a grandfather completely changes the future, including one's own birth and the very possibility of killing one of the ancestors.
Theories that allow for transitions in time allow several options for the development of such situations.
The first assumes that somehow the space-time continuum itself will not allow such possibilities (without explaining in any way how and why this prohibition can be realized).
The second option (according to Everett) assumes that a change in the past generates a new chain of events, making the entire history of the past before the change unreal. The grandson himself, who killed his grandfather, disappears, as never existed in the new line of time.
Cyclic time theory, following inferences from quantum mechanical equations, makes the observer's (or time traveler's) past as uncertain as the future. This means that, moving into the distant future, the traveler finds himself in his past, replacing himself with the past with a more accelerated and information-rich present.
Any changes made in the future (like the murder of an ancestor) will not lead to the disappearance of the chronaut, since all generations of distant ancestors, as well as future descendants, remain undetermined for a person who has severed causal ties with the world. But change is bound to lead to a new future that the time traveler will relive as he faces the consequences of the changes.
The process of replacing the traveler's past with a new one will take place at the atomic level, without creating any tangible effect for the traveler, having assembled a new carrier body from the surrounding matter for the consciousness of the renewed person.
To be continued…
