What is the paradox of no causality in time travel?

Question

Say you go back into time and prevent your own birth. If causality is an active force, then this is not possible and is a paradox, correct? But if causality is not an active force, then you would simply exist in this universe despite preventing your own birth in the universe you came from. However, according to Wikipedia, "while this would negate the grandfather paradox itself, it says nothing about other changes made to the timeline (for example: what if you killed someone else's parents?), and may assume a separation between the individual's timeline and the "main" timeline of the rest of the universe, essentially resulting in its own paradox -- that the lack of causality as an active force that affects the individual separately from the rest of reality in itself requires that causality be an active force that affects the individual separately from the rest of reality." I can't make sense of this; can someone explain the paradox of no causality to me?

Answer 1

if time travel was possible, then the the time line would follow a rule of one line back but infinite lines forward. because you could go back along your time line, but once you have entered the past you have already altered your future and you could never get back to were you came from it may look the same but some event no matter how big or small has been changed. so killing yourself as a baby will kill yourself in that time line but not the one you are in. of course by going back in time you have created matter or at least made the matter in yourself twice in one dimes ion and absent in another, so both of them and the dimes ion between them and around them would be destroyed.

Answer 2

If you were born then your parents met and gave birth to you. This is always a given. Even if you tried to go back and prevent that meeting by whatever means, something apparently happened to thwart your efforts. Otherwise you wouldn't be here to consider trying in the first place. The event of your parents' meeting and subsequent event of having you both happened. No paradox at all. Any universe or timeline or whatever term you use where you exist means you never succeded at preventing your parents' from getting together.

Answer 3

my guess is that if you killed your parents before you were born and you still continue to live, then you created an alternate time line where you were not born but as you still exist, in your own "real" time you couldnt have done it....Robert A Heinlein has a few fiction books that talk about this alot...one of the best is "The Number of the Beast"