Time travel can be possible, if we maintain this ability our lives would change. I've always been fascinated by the idea of travelling through time and space, but even with this extraordinary power it is so unstable and we don't know how it will effect our current timeline. Today, I will be attempting to understand and to uncover some of the mysteries of time travelling.
If we are able to Time travel to any point in time, our best bet is wormholes as described by Einstein. But, we haven't found one and even if we do it needs so much testing to see if it is stable for objects and humans. Let's suppose we travel in almost the speed to light, we will be going through space and coming back to the earth for a year, when you will come back it will be 100 years in the future. This means that you didn't travel through the future but only accelerated the motion of the traveling, because we are always traveling to the future and that is because time is a one way and doesn't stop. Thus, if we feel like it is 100 years for us, you will be experiencing a year for you but it is the technically normal because we will feel like nothing is changing, only the time being relative to both of us. This means, there is a possibility of someone time travelling right now at the speed of light but we are here experience it in a slow motion from his perceptive but normal to us, the only thing that would seem strange to him is the things he missed while he was gone but for us it is always been the same. The challenge is going back to the past, and if we were able to do such thing. He will comeback and we will suppose he changed something that was destined to be in the future, which means he will be changing the future and we will be left with a conclusion just like the grandfather paradox. There is a way to explain this phenomena of knowing the future and coming back to prevent something from happening which will change your future , and that is by multiple worlds. But even the action of going to the past is itself strange and confusing, because we know that time is one way. It will be like travelling the whole universe into the past with you, and if that is not possible then you will "possibly" be travelling into another world not the original one that you came from.
In quantum mechanics, Schrodinger exposed the idea of superposition in his famous experience "Schrodinger's Cat" which declares that when placed in a superposition you will experience both events at the same time. Let's say you killed yourself in the past, thus there will be no "you" to go to the past, therefore you will be both alive and dead at the same time according to quantum mechanics. But, I'd like to present my theory about this whole thing. If I kill myself in the past, then there is no "me" to kill me in the past so i'll be vanishing from reality itself. But, I don't think that what is going to happen. I think I will be placed in a state where I don't belong to nothing and nowhere, meaning i'll belong to no place and i will be separated from whole thing and continue my life in the current time line. I will belong to no place because I am dead in my current timeline. My theory seems to go well with the quantum world, it can only be applied by ignoring the multiple worlds theory but rather in a one timeline of predestination. The question of why do you have to be alive even with the action of killing your old self. It seems that if you were to kill your past self then there will be no you but that doesn't mean that you should not exist because you killed yourself, you will just simply belong to nowhere. There is no other way to really phrase it, you will have to think about it in your own and come to what you feel like is true.