Many-Worlds Interpretation

I came across an article in The Hindu last week about a scientist, Hugh Everett and his theory, which, many notable scientists of his time discarded as rubbish. The theory is now being called by many as 'Many-Worlds Interpretation' - the existence of millions and millions of parallel universes. I have often thought about it myself, though I always referred to it as The Fifth Dimension - The 3 spacial axises -x,y,z and time, t make 4 dimensions while the fifth being probability (its a misnomer but I stuck to it). It must have actually been 'the set of probable events that could occur from a scenario.' At a given place (x,y,z) and time (t), one could react in many different ways to a particular situation, leading to many parallel concurrent universes of events. And here I am, reading about something I have thought about, something that someone has postulated as a theory and many 'now' believe to be true. I therefore decided to find out and understand more about it. This was also an opportunity for me to tell myself that my physics degree was not a complete waste of time and effort. Time, because I spent a few years in the name of studying physics. Effort, because I 'tried' to understand my coursework, and the question 'did I really understand?' is irrelevant here. psi is always sigh for me; and I still think of a 'bra' when someone mentions 'a bra and a ket'.

I googled to read several related articles on the theory, understanding something in some of them and nothing in many of them, until I finally stumbled upon this link, which seemed to be the common-man's version the Many-World's Interpretation.

For the many of you who do not have the patience to read the entire 44 page (A4, Times New Roman, 13.5) synopsis, here is what I think as a simplified version of the simplified version.

'Everything' (universe) is in a wave form. It all started as 'one' grand wave that branched into several branches (possibilities) everytime there is an event. These branches never come back to intertwine with one another. The physical substances of the universe (me, you, men, women, dog, cat, etc., etc.) are called 'macrosystems' and are part of the wave. When more than one macrosystem interacts with other macrosystem(s), it causes an event, which irreversibly alters the state of all macrosystems (me, you, men, women, dog, cat, etc., etc.) involved in the interaction. Upon this interaction, the 'wave' branches into several sub-branches based on the state (reaction to the event) of all involved macrosystems. At this juncture the macrosystems (me, you, men, women, dog, cat, etc., etc.) become copies of themselves and join each branch. They also become unaware of the other copies of themselves in the other branches.

The article also talks about the concept of 'many-minds' - 'an infinity of separate minds associated with each single brain 'state'. When an 'event' occurs, a single physical brain state with its infinite separate minds are 'differentiated' by the event. It also states that the 'quantum noise' of these interactions (events) are so low to affect the free will of individuals.

Some questions:

Is there a possibility of two worlds merging together as one in some distant future?

For such a thing to happen, all the constituents of the two worlds must coincide with their counterparts simultaneously, and there are millions and millions of constituents that form a world and therefore it is virtually impossible for such a thing to happen.

Where do the other world's exist?

In space and time, the other worlds are in the same place as where our world is. However, they differ in the fifth dimension, the dimension that we are unable to experience.

Why am I in this world and not another?

I would like to quote the same analogy used by Michael Price, the author of the article.

Fred has his brain divided into two and transplanted into two different cloned bodies. Let us further suppose that each half-brain regenerates to full functionality (Split brain experiments were performed on epileptic patients. Complete hemispherical separation was discontinued when testing of the patients revealed the presence of two distinct consciousnesses in the same skull. So this analogy is only partly imaginary.) and call the resultant individuals Fred-Left and Fred-Right. Fred-Left can ask, why did I end up as Fred-Left? Similarly Fred-Right can ask, why did I end up as Fred-Right? The only answer possible is that there was no reason. From Fred's point of view it is a subjectively random choice which individual "Fred" ends up as.

To the surgeon the whole process is deterministic. To both the Freds it seems random.