Debates about the possibility of time travel are indeed exciting and confusing scientific discussions. In theory, many scientists say that time travel is very logical and possible. Time-traveling or time travel is the concept of moving or moving a material / entity to several different points of time and space that can be different, can be in the past or future.
However, scientists also do not deny that if time travel is carried out it can lead to a ‘forbidden concept’ called paradox. The time travel paradox is a theory which states that the same two entities cannot be met in a different space and time.
For example, you travel time to the past and meet a teenage version of your parents who are dating and without you realizing it, your actions at that time made them not marry later on and of course you will never be born. Then, the concept of paradox arises, which child are you from?
There are several paradoxes of time travel that are quite well-known today.
1. Grandfather Paradox
This paradoxical concept is the most popular. In short, you travel time and kill your grandfather because in the time you were, your grandfather gave birth to a generation of families that have destroyed human civilization.
You committed murder before your father or mother was born or before your grandfather met your grandmother, then your father or mother was never born, and the effect is that you will never be born and will never travel time to the past to kill your grandfather.
Then, if you have never traveled time to the past to kill your grandfather, then your grandfather lives, your father or mother is born and you too will be born. Then, you go back in time, to kill your grandfather. This paradox creates a ‘looping timeline’. Confused? It’s paradox!
2. Predestination Paradox
The essence of this paradox is that everything has been predestined, and cannot be changed because history has recorded that an event will surely occur and cannot be changed. Predestined Paradox is designed to create the same event as it should.
Time traveler traveled time to the past to change an event but his efforts made him return to the past to change the event. In other words, actually no event has been changed. So, we cannot save JFK from murder, will not be able to kill Hitler before he is in power, cannot stop world war and all events recorded in history and indeed must occur.
Example: If you have watched the Time Machine movie (2002) you will see an example of a predestined paradox. In this film it is told that Alexander Hartdegen, a scientist, lost his fiancee, Emma because he was killed in a robbery. This incident, made him to save his life by building a time machine.
This time the machine is used to return to the past to prevent the death of his fiancee. However, death is unavoidable. And every time he rescued his fiancee, instead he saw his fiance die in a different way.