time machine story!

[keannu]

In "one of your parents could never be born; therefore, you could never be born", do both "could" mean unreal condition or real condition? The two can be interpreted in both ways, so it's confusing.
I need a savior!!!

ex)The concept of moving freely to different points in time is known as time travel. Time travel is impossible to consider without addressing the issue of paradoxes. One of these is known as the "grandfather paradox." Imagine that you invented a time machine and could travel into the past. What would happend if you met your grandfather when he was a young man and accidentally killed him?
That would mean that one of your parents could never be born; therefore, you could never be born. But if you were never born, how could you exist to travel back in time and kill him? Like all paradoxes, it's a logical contradiction.

[5jj]

Like all paradoxes, it's a logical contradiction.

Writers of science fiction have to decide for themselves what tenses are appropriate. The intended meaning has to be guessed from the full context.