So I was talking to this guy about the grandfather paradox and he mentioned to me that if someone named Larry traveled a couple thousand years in time and had a huge family then eventually trickled down to where his grandma had the bloodline of his Great, great whatever Grandson and so he himself had his grandma was his own bloodline to make himself his own grandson. But here is where the guy I was talking to said about the situation: If a time traveler did that then it would create a new timeline but it's still weird thinking about the possibility of someone being their own grandson even if it took a couple thousands of years to happen. I don't fully understand this grandfather paradox, but we were talking about it this way one day. Maybe you can help me better understand this one?
Skarpz,
He "borrowed" the idea from Robert A. Heinlein's short story "All You Zombies" where the time traveler, through a series of events involving his travels via a time machine, becomes"the bartender" who gives him the time machine, himself, his own his own daughter, mother, father, grandfather and grandmother - not to mention that his time machine, through the same set of events, is never actually invented. It's a "bootstrap" paradox - a set of circumstances that seem to create themselves without any intermediate chronologically ordered set of events. The creation of alternate univsrse is
not implied by the paradox. The alternate universe "dodge" is a contrivance designed to avoid the paradox.
In quantum physics the "alternate universes" created in the Many Worlds Interpretation (MWI) come from the probability wave (a mathematical construct of the science). The possible outcomes (alternate universes)
only includes that which is included within the probabilities given the laws of physics. It is a false statement that the probability wave includes "everything that one can imagine". If that were the case then flipping a two-sided coin would result in a infinite number of non-inclusive results - yet the possible number of results is three: heads, tails, lands and balances on the edge. Sure, you can get an infinite number of results if you include the orientation of the coin when it lands, but all of those results are gauged by heads, tails and edge. "The iron coin became a gold coin", is something that is included in "everything one can imagine" but it is not included in the probability wave of flipping an iron coin.
Moreover, the same set of laws of physics also state that there is no possible way to communicate with these alternate universes. Any attempt to communicate with them involves the same general scenario - a probability wave, possible outcomes, an action and alternate universes created based on the probability distribution. Attempts to communicate with the alternates just results in the creation of more alternates. "Theories" that postulate such communication negate the underlying premise of MWI and, therefore, are not MWI at all.
Your best bet is to do your own research and study of the grandfather paradox.
