Imagine Bob Dylan was singing in a concert holding the microphone in his hand. Suddenly a screeching sound occurred out of nowhere, got picked up by his microphone and got amplified by the amplifier. Now the amplified sound will again be picked up (the feedback problem) by the microphone, again be amplified. Again be picked up and again be amplified. Again be picked up, again be amplified. It wouldn't stop until it damaged the whole sound system (in real life filters are used to avoid this problem).
Now imagine Steve who is the only son of Mark. Steve was born in 2000, Mark was born in 1970. Mark was again the only son of Greg who was born in 1940. Steve is a smart boy and knows how to travel back in time. So he traveled back in time and killed Greg in 1960.
Now two problems occur.
1. If Greg died in 1960, Mark was never born. So who is that Mark that Steve knows? Isn't he a ghost?
2. If Mark was never born, how come Steve exists? Who gave birth to Steve?
There is a hypothetical solution to this problem.
When you travel back in time, you can never affect the natural course of incidents. You can only be a observer and you will be invisible. The reason you will be invisible is that if you travel back in time, you will not be in the same time-space coordinates that you are in. There the concept of time will be different and the biological configuration of the humans won't allow them to see you. So you can only observe and cannot change anything.
So even when Steve will travel back in time, he won't be in the same space-time coordinates. And also, he cannot affect things there. He can only observe Greg and his activities.
I remember reading somewhere, some famous person said "I am not I. I am a copy of I". What it means is even if one of the 'I's gets killed, the other 'I's will still survive in another universe.
It will be nice to remember that there is hardly any difference between a sound wave and a radio wave except their wavelength difference. We can hear the sound waves, we cannot hear the radio waves. So if our biological structure hasn't grown to sense that band of frequency, we won't notice it naturally. So in a parallel universe, you have a higher chance to be invisible assuming that the creatures there have responses to another band of frequencies.
Some interesting points come out from this discussion.
1. History won't follow the same pattern for the same person in different universes.
2. History synchronization is not possible. Even if it was possible, it would hardly overlap.
3. People can be treated as variables in a universe. While the number of variables will be same in different universes, they will have their own functions (something like the role of X in different mathematical equations. Based on the equation, X will give have different values (in our case, different life history)).
So what do you think? You wanna meet your other self? Does your other self love the same person you love?
You may find out some even better logical deductions.
Till then, cheers!!
Disclaimer: The above post is purely a child of thought and should not be used as a reference. The purpose of this post is to encourage the readers to think differently and produce even better ideas.
If you have missed my other two posts on time travel and parallel universe, you can click the green links.