A Time Travel Issue

[Acujer]

So I've been getting my time machine all ready. I haven't decided on what date I'm going to go back to yet. I have some concerns that no book, comic or movie seems to address.

If I go back in time, let's say 10 years ago, and I alter an event in my life, obviously we all know that when I come back things will be different. It's a snowball cascade effect. These changes we won't know if they will better until we come back to the present and see. But my question is what happened to the people I left behind originally? Where do they go? Person X and Person Y are hanging out. Person X says goodbye to Person Y and he goes in the time machine. Person Y waits. After altering events of the past, Person X returns to the present to find Person Y totally different. But the original Person Y, well, what happens to him? Does he all of a sudden go poof and he's altered or does he continue to exist on a parralel reality? There must be two realities or dimensions existing simultaneously. One original reality and one changed reality. That would indicate that you haven't really altered events but have actually created a parralel universe.

Does anyone have any suggestions?

 

[MattDouglas]

If you want me to hair-split your question staying within your box, I suppose I could wax on about it.
But I'll go outside the box instead.
Time travel doesn't exist and never will.
Because time doesn't exist. It's a conceptual reality, not a physical one. While the whole idea of a space-time continuum makes for some cool sci-fi stories (I did dig the Star Trek remake), it's also bullshit.
Now, if you're asking this question because you're actually writing this post in order to get ideas for a story you are working on, I feel I'd be, at least for now, stealing the joy of your creative processes, if I started writing it for you.