Some thoughts on Quantum Theory

[Braedley]

Before I start, I'd just like to state that I only have a passing knowledge on the topics to be disscussed aquired through sources including (but by no means limited to) the CBC radio science show Quirks and Quarks, my grade twelve physics class, http://www.slashdot.com, and general internet research. That being said, please feel free to correct me when I'm wrong.

The grandfather paradox: You go back in time in order to kill your grandfather (who is, as example a rapist and mass murderer), or some other ancestor before the next person in your lineage is concieved. What happens to you if you succeed? (BTW, a large number of reputable quantum physicist say that time travel is theoretically possible, but we'll touch on that later.) One theory states that you are basically who you are through the culmination of all the quantum events that have occured during the entire existance of "this" quantum reality. This means that you are who you are because of things that you have done in the past, even if that past contains a future version of yourself. This leads to the result that you cannot cause the death of a direct ancestor before the next of your lineage is concieved (and potentially even born). If you try, events will conspire such that you fail (in some manner) to succeed. This also means that at some point in your future, you will make an attempt to kill said ancestor by means of travelling back in time, and will ultimately fail. This brings up a point that may be a little disturbing to some: If all the above is true, then we have no free will, only the illusion of free will.

Multiple Quantum Realities: (MQR) This theory states that all possible ouputs resulting from input(s) to a quantum event are expressed each in a separate reality. As a result of this quantum event, each new reality accuires a slightly different quantum signiture. As an example, you have a gun with a quantum trigger pointed at your head. Pulling the trigger generates a quantum event with the possible outputs being that (1) the gun fires and (2) the gun does not fires. This action creates a new separate reality to go anlong with the one you already occupied (so now there are 2 realities). In one reality, you are alive and well, in the other, you are dead.

These two theories by themselves do not mean that time travel into the past is impossible, but lets put them together.

My conclusions from the grandfather paradox for now boil down to: if in your past a future version of yourself appears, then you are destined to travel to that point in the past from whence you came from in the future. The theory of MQR stands as stated earlier.

For expediancy, lets assume that your arrival in the past generates a quantum event from which there is more than one possible output. This means that your future self has just created a divergence of quantum realities in your past, and that you are also destined to travel back in time. However, you have a slightly different quantum signiture in each of the realities, but only one when you first appear in the past.
Does this mean that time travel into the past is impossible, or do all the realities somehow coverge into one reality, despite the fact that there will be differences from each reality, or are there new realities created (or were they there all along) for the parallel realities?

Or have I just been speaking out of my ass?

As a side note, you may notice that this discussion does not dismiss the posibility of travelling into the future, however, returning from the future is another story.