On Tue, Jan 21, 2014 at 1:30 AM, meekerdb <[email protected]> wrote:
> On 1/20/2014 5:56 PM, Pierz wrote: > >> A second question/thought on MWI. MWI proposes that the entire universe >> splits at the point of wave collapse, or rather that it is continually and >> infinitely splitting with every possible quantum state. This has been >> understandably criticised as a vastly extravagant explanation. A whole >> universe, or even infinity of universes, for every quantum interaction >> seems a high price to play to eliminate the weirdness of wave collapse. Yet >> it seems to me that we can still get the explanatory benefits of MWI >> without this extravagance by seeing the situation slightly differently. >> >> I'll explain by analogy. I'm a coder. In the old days I used to back up >> my work by making a complete copy of it and putting it in an archive >> folder. Nowadays I use git, a source control system that keeps track of the >> history of my code and allows me to revert back changes to an earlier point >> in time. Depending on how often I "commit" my work, I can have an >> arbitrarily fine level of versioning. If git was stupid, it would copy my >> whole code repository every time I committed a change, and my disk would >> rapidly fill up. It would also be impossible to merge the work of another >> programmer working on the same code base because the system would only have >> complete individual snapshots. It would have no information about *what* >> changed between snapshots. But git is smarter than that. It records only >> what I changed in each commit. Thus I don't have to worry about my disk >> filling up, and I can happily merge someone else's changes - just so long >> as we don't both try to change the same line of code. >> >> To think that in MWI, a *whole other universe* is created when a binary >> quantum event occurs is like imagining the multiverse works like my old >> backup system. One thing changed, so if I want to keep a record of the >> earlier state, I have to copy *everything*. This is the way that Deutsch >> seems to talk about the situation. But it makes more sense to me to think >> of it as like git. If the universes diverged by only bit of information, >> that one bit is the only thing that is "recorded" so to speak. When the >> spin of a particle is measured here on earth, causing the universe to >> split, there is no need at this point to think that there are suddenly two >> Plutos, one for each spin state. What does Pluto know about the change? >> Later, this one bit change will ramify out, causing divergent information >> flows in the two "universes" which will eventually lead (possibly? >> necessarily?) to two completely different universes. But to the extent that >> any region of one universe is identical to a region of another universe in >> the multiverse, shouldn't we regard those regions as belonging to one and >> the same universe, merely with the potential to differentiate from one >> another? >> >> In other words, we're better off thinking about locally branching >> information flows than an infinite filo-pastry of universes. We can still >> answer the question of where the computations of a quantum computer take >> place - they occur in a multi-dimensional local information space. Each >> calculation line that contributes to the final result occurs on its own >> information thread as it were, but it does not require a whole universe to >> occur in. >> >> Maybe this economical view is the way MWI theorists actually do see the >> situation? If so, I wish they'd talk that way. It makes the theory a lot >> easier to swallow in my view. >> > > I agree that the "multiple worlds" generally differ only microscopically > and so the count as the same world so far as we're concerned. But the > changes/divergences are not discrete. A radioactive atom is in a > superposition of decayed and not-decayed and on the decayed side there is > change of the wave-function propagating at c or less that is gradually > differentiating one world from the other at a microscopic level UNTIL in > some world the decay is detected and amplified (say by a geiger counter). > > And so when I am approaching a fork in the road while driving and on one fork I will get into an an accident and on the other I will not, does that choice count as a superposition? Richard > Brent > > -- > You received this message because you are subscribed to the Google Groups > "Everything List" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at http://groups.google.com/group/everything-list. > For more options, visit https://groups.google.com/groups/opt_out. > -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
