The idea of time travel can go back centuries, in fact anyone who has had a profound sense of regret has thought of having a time machine. To go back in time to right a wrong, to do or undo something they believe is the source of their mental downpour. Philosophical and Literary evidence aside, Science has too, had a beckoning with Time Travel. To peer into the future that helps the contemporary world has been almost every budding scientist’s dream or at least a thought that has crossed their mind.
Einstein came along with his theories of relativity and almost transformed how we looked at time and space. He, to put in simple words, proved that the faster one goes in relation to a constant, will be affected by time at a different speed than the constant. This means that the faster you are travelling through space, the slower time goes for you. This can be the only scientific way to time travel so as to say, for now at least. But even if the ‘time travel’ that is depicted in movies and literature were to be fulfilled, there are a series of inconsistencies that are associated with time travel that lead to paradoxes.
The time travel paradoxes which follow fall into two broad categories:
Closed Causal Loops
Paradoxes like the Predestination Paradox and the Bootstrap Paradox, which involve a self-existing time loop in which cause and effect run in a repeating circle, but are also internally consistent with the timeline’s history.
Paradoxes like the Grandfather Paradox and Polchinski’s Paradox, generate a number of timeline inconsistencies related to the possibility of altering the past.
Now let us talk about each paradox in detail
The Predestination includes that the individual traveling back in time is linked to the past and that past further links the future events that were supposed to be prevented. This means that the time traveller is inexorably linked to the past such that no matter what they do to prevent the future, they will end up failing at that and the future still remains. They get caught in a temporal causal loop. As they are the reason for the loop to begin and have no end.
The entire plot of the movie ‘Predestination’ is centered and revolves around the concept. Some things are probably just meant to be as they are and can not be changed. Feeling upsurged with confusion? Try delta 8 to get mental clarity to read more about such paradoxes. Choose your favorite delta 8 cartridge here.
This is a paradox riddled with paradoxes in it, which make this a really confusing and probably the most known paradox. Say, you go back in time and kill your grandfather before he gets a chance to meet your eventual grandmother. You would cease to exist as you are and hence would be incapable of going back in time to kill your grandfather. A major paradox isn’t it? But it only gets worse. Theoretical physicists believe two possible outcomes are possible –
Timeline Protection Hypothesis
No matter how hard you try, you won’t be able to kill your grandfather. Imagine taking a gun to your grandfather, you pull the trigger, but it doesn’t fire. You aim elsewhere and it shoots the bullet. It happens every time you point the gun at your grandpa. The timeline is keeping itself secure for you to exist and come back in time.
You do manage to kill your grandfather, you have accomplished what you wanted to and travel back to your time. Only thing that is pressing is that a new timeline has been created and you do not exist in this timeline. No bank records, social security number, nothing is known of you, as you just don’t exist.
The Bootstrap paradox is by far the most fascinating and unrelenting of all the paradoxes. This paradox deals with a person, object or a piece of information being sent back in time, where it results in an infinite loop of being in the past, present and future without any discernible origin. This is also called the Ontological Paradox, as Ontology is a branch of Philosophy, dealing with the nature of being or existence.
Assume if a scientist sends a book with the mechanics to build a small time machine. The book was found by a scientist in the past and they work on it to finally make it in the time machine and use the time machine to send the book back in time. So, the book was the reason for the time machine to be made and that time machine is used to send the book back in time. Hence the book has no origin and a paradox is created.