First, I must say that I am a fervent believer of MWI. Even when I was much younger at school, I believed that any action led to the creation of many alternative worlds in each of which the action was done in a different fashion (or not done at all). More than that, at each instant, a world where the whole universe stops existing could exist. This wouldn’t be a problem either.
It’s late at night (5.00 am) and I’ve been reading a lot of articles about quantum physics, MWI and more. I’ve read that some theories (quantum suicide and immortality) are giving an extra role to conscious beings, even making them immortal: the consciousness would automatically always pass to the “currently alive host” between different worlds, and as a world exist for each probability (even most improbable ones), and as the probability of one being immortal is not zero, conscious beings would therefore be immortal.
This would make some things possible, like the Infinite Improbability Drive: onboard conscious beings could be systematically destroyed until they reached their destination. Consciousness would be passed to the last alive one until destination is reached. Once destination is reached with the conscious beings onboard, they could resume creating an infinity of alternative worlds with their choices.
While this theory looks interesting, I believe its creation might have more to do with the desire to avoid death than anything else. First, I don’t believe consciousness has any impact on physical properties of a being, and second, I don’t know much people who have already managed to live infinitly (maybe I’m not in the right MWI path, but with all those conscious beings, I would hope to meet one someday).
Instead, I believe consciousness is also being duplicated in each alternate world, and I can only hope that the consciousness I am currently conscious of will live long and prosper. There might be an alternative world where it will not die, but the low probability of it being the one I’m currently conscious of is low.
The MWI theory also solves problem of traveling into the past. Changing the past (just “being there” is a change) would simply create an alternative world in which there is indeed someone at this place and time. The real challenge would then to be able to travel to defined alternative worlds. This is potentially more complex, especially due to the infinite number of alternative worlds (going in an alternative world will create at least two more alternative worlds).
Another option is the possibility that when we decide something of our own free will, this decision is not enough to create an alternative world (ie. there is no probability that we would have done otherwise), in which case creation of alternative worlds would be limited to half-dead cats.
I am currently unaware of any way to prove or disprove the MWI theory, however it seems that disproving quantum physics would disprove MWI in its current form. This is a complex way of trying to understand our current universe, and maybe in a few years I’ll have a different theory in mind, but for now it’s the best I can think of (well it’s 5.30 am, so I might not be in the best state to think about anything).
One last though: if I download some entropy and base the choice between two set of actions on it, I might be able to separate the two set of actions in different worlds which branching point would be when the entropy itself was generated. This would be similar to the Schrödinger’s cat experiment.
