On Wed, Nov 15, 2017 at 07:33:12AM -0800, agrayson2...@gmail.com wrote: > > > On Wednesday, November 15, 2017 at 7:51:09 AM UTC-7, Bruno Marchal wrote: > > > > > > On 15 Nov 2017, at 00:17, agrays...@gmail.com <javascript:> wrote: > > > > > > Multiverse arose in the context of string theory, after Everett's MWI. The > > difference between Multiverse and MWI is striking and obvious. > > > > > > > > To my knowledge, "multiverse" is the terming given by David Deutsch for > > the Many-Worlds. Then, String Theory has used that terming in its context, > > but it could have used "many-World". String theory is a special application > > of QM. > > > > *As "Multiverse" is now usually used, it refers to the multitude of > possible universes with different basic parameters that might exist in > parallel as claimed by String Theory, whereas the way Many Worlds is used > it refers to the (uncountable!) universes allegedly automatically created > when Joe the Plumber goes into a lab and shoots an electron at, say, a > double slit. The two types of multiple worlds are conceptually different, > hugely different, and that was all I was asserting. To claim that the two > concepts are somehow the same is a common error, and egregiously misleading > to equate them. * >
Multiverse can refer to any of the ensembles, depending on the author. String theorists will be referring to the string lanscape, as you observe, but for say someone like David Deutsch, Multiverse refers to the Many Wolds of MWI. I think Deutsch coined the term originally. Yes it is important to distinguish the difference ensembles, as in Tegmark's classification of multiverses. IIRC, the string landscape is a level 2 multiverse and the many worlds a level 3 multiverse. > > *I am interested in your opinion that, as I contend, the universe we > inhabit, must be finite in spatial extent since it is finite in age. This > is the elephant in the room that no one wants to discuss, apparently. * > As Brent explained, if the universe is infinite in extent at t=0, it remains infinite in extent at finite times. -- ---------------------------------------------------------------------------- Dr Russell Standish Phone 0425 253119 (mobile) Principal, High Performance Coders Visiting Senior Research Fellow hpco...@hpcoders.com.au Economics, Kingston University http://www.hpcoders.com.au ---------------------------------------------------------------------------- -- 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 everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
