Norman Samish wrote: > I read Fabric of Reality several years ago, but didn't understand it well. I > intuitively agree with Asher Peres that Deutsch's version of MWI > too-flagrantly violates Occam's Razor. Perhaps I should read it again.
This is diusputed, e.g. in http://www.hedweb.com/manworld.htm Q21 Does many-worlds violate Ockham's Razor? William of Ockham, 1285-1349(?) English philosopher and one of the founders of logic, proposed a maxim for judging theories which says that hypotheses should not be multiplied beyond necessity. This is known as Ockham's razor and is interpreted, today, as meaning that to account for any set of facts the simplest theories are to be preferred over more complex ones. Many-worlds is viewed as unnecessarily complex, by some, by requiring the existence of a multiplicity of worlds to explain what we see, at any time, in just one world. This is to mistake what is meant by "complex". Here's an example. Analysis of starlight reveals that starlight is very similar to faint sunlight, both with spectroscopic absorption and emission lines. Assuming the universality of physical law we are led to conclude that other stars and worlds are scattered, in great numbers, across the cosmos. The theory that "the stars are distant suns" is the simplest theory and so to be preferred by Ockham's Razor to other geocentric theories. Similarly many-worlds is the simplest and most economical quantum theory because it proposes that same laws of physics apply to animate observers as has been observed for inanimate objects. The multiplicity of worlds predicted by the theory is not a weakness of many-worlds, any more than the multiplicity of stars are for astronomers, since the non-interacting worlds emerge from a simpler theory. (As an historical aside it is worth noting that Ockham's razor was also falsely used to argue in favour of the older heliocentric theories against Galileo's notion of the vastness of the cosmos. The notion of vast empty interstellar spaces was too uneconomical to be believable to the Medieval mind. Again they were confusing the notion of vastness with complexity [15].) > I even attended a lecture by John Wheeler, David Deutsch's thesis advisor. > He gave me the same sense of unease that FoR did. > > While I have no better explanation for quantum mysteries, I remain agnostic. > "MWI's main conclusion is that the universe (or multiverse in this context) > is composed of a quantum superposition of very many, possibly infinitely > many, increasingly divergent, non-communicating parallel universes or quantum > worlds." (Wikipedia) > > I also can't buy "wavefunction collapse." That is unofortunate, because if you do not have collapse, you have MW, and if you do nto have MW, you have collapse. > Perhaps some undiscovered phenomenon is responsible for quantum mysteries - > e.g., maybe the explanation lies in one or more of the ten dimensions that > string theory requires. What is "responsible" for quantum phenomena is the way the universe works. What needs explaining is how the appearance of a classical world-re-emerges. > Maybe these undiscovered dimensions somehow allow the fabled paired photons > to instantly communicate with each other over astronomical distances. This > is a WAG (wild-ass guess) of course, but it's more believable to me than new > universes being constantly generated. This is already explained: what allows them to communicate is the fact that they occupy an infinitely-dimensional Hilbert space. What needs explaining is how that ends up looking like 3D classical/relativistic space. > However, I CAN see some logic to the idea that Tegmark introduced me to - the > idea that, in infinite space, a multiverse exists containing all possible > universes - and we inhabit one of them. Then the quantum universe will be one of them. But why shouldn't it be the only one ? > I believe that, in infinite time and space, anything that can happen must > happen, not only once but an infinite number of times. --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Everything List" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~----------~----~----~----~------~----~------~--~---
