On 25 Dec 2012, at 19:35, Brian Tenneson wrote:

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At least in the video (skip to 43:14), Tegmark estimates that ourdoppelgangers are 2^10^118 meters away which probably puts it pastthe range of direct testing and, consequently, makes it notfalsifiable.

`But this is in the "many worlds" of one world being infinite and`

`sufficiently homegenous. It is not the Everett, nor the comp`

`Doppelgangers.`

`Also, it is not clear why would this be not testable, as we can test`

`first person indeterminacies on such "Garden of Eden" configuration,`

`and compare with the observation.`

`May be *that* can win the 1p-(plural)- measure battle, but I guess`

`this is today just speculation.`

`I don't think Tegmark takes the 1p indeterminacy into account, except`

`in the quantum wave, but not on math in general or in arithmetic.`

Bruno

Regarding (4), I think the disparity between you and Tegmark can beexplained by having different definitions of universe andmultiverse. Of course, if you have a metauniverse, then you'd havea metametauniverse, ad infinitum. There is only one "totality ofall that exists" and I bet that if you were to explain what you meanby the One to him, he would agree that there is only one One. Whenhe uses an aphorism like "multiverse" he may as well be saying "polymega galaxy cluster" or some such. In other words I don't thinkTegmark believes in multiple Ones.In his mathematical universe paper and ultimate ensemble paper, heposits that there is only one type of existence which would simplifythings (a la Occam's razor). Instead of there being mathematicaland physical existence, there is an identification between the twoso they are seen to be one in the same. This merges the spaces"mathematical objects" with "physical objects". He argues this inthose papers (though to me sometimes it seems to be merely aplausibility argument).Now if ME=PE, then one natural question is which mathematicalstructure is "the totality of all that exists" isomorphic to? Inother words, what is the One? What is the universe? Or to abuselanguage a bit, what is the multiverse? This is a question thatI've been thinking about for a while now and I'm really not sure.The current idea is to take the category of all mathematicalstructures C (which is large, unfortunately), and embed that into acategory of functors defined on that category (a la Yoneda's lemma),in such a way that every mathematical structure is embedded withinthat category of functors (called a "cocompletion" of C), a sort of"presheaf" category. To have a single mathematical object that allmathematical structures can be embedded would give us an objectthat, in a sense, contains all structures. If one follows Tegmark'sidea that ME=PE, then a definition for universe just might be amathematical object (which by ME=PE is a physical object) thatcontains, in a sense, all mathematical objects (i.e., all physicalobjects). It's not super clear to me that the cocompletion of thecategory of all structures C exists though since C is not a smallcategory and thus Yoneda's lemma doesn't apply. I would have tofine-tune the argument to work in the case of the category C I havein mind.If the cocompletion of C is the One, that which all mathematicalstructures can be embedded, then the parallel universe questionwould be a matter of logic and category theory; it would depend onhow you defined "the visible universe" and "parallel" universe.On Tuesday, December 25, 2012 6:34:45 AM UTC-8, rclough wrote: Hi Brian TennesonTegmark has many many good ideas, but I am not a believer inmultiverses,which only a strict mechanistic 19th century type can believe. Multiverses defy reason. Just off the top of head:1) For one reason because of Occam's razor: it is a needlesscomplication,and the universe (or its Creator) does not do needless things, because IMHO the universe is purposeful. 2) "Purposeful" meaning that Aristotle's end causes are needed for a final collapse, as they are for life, which is not mechanistic.3) As in life/mind/consciousness/intelligence, which are alsopurposeful.4) In order for there to be multiple universes, there would have to be multiple platonic Ones. But there can only be one One.5) Multiverses are mechanistic and so in spacetime, but consciousslifeand all that other good stuff are outside of spacetime. Would the minds of multiverses be mashed together ? And all particular lifes would have to terminate at the same time.6) There is no non-Boltzmann physics which is required for a finalcollapse.Time has to begin to travel backwards as things reorganize,in which case the final collapse should be a reflection of theinitial creation.That would be cool. 7) But each universes being differemnt, they would not be expected to all terminate at the same time.8) One might conjecture also that the presence of life,consciousness andintelligence (which are all individual, personal, subjective) are not mechanical and so cannot be part of a multiverse. It's each man for himself. Along these lines, because of natural selection and different worlds not being all the same, evolution would not occur in parallel.9) Besides, there are alternate possibilities for a quantum wavecollapse.10) In a related matter, one of the multiverse sites cited WilliamJamesas a proponent. Because of his pragmatism, his multiverses arise because there is no fixed general in pragmatism for each particular. There are as many generals (additional universes) as you can think of. These obviously would not be parallel. [Roger Clough], [rcl...@verizon.net] 12/25/2012 "Forever is a long time, especially near the end." -Woody Allen ----- Receiving the following content ----- From: Brian Tenneson Receiver: everything-list Time: 2012-12-24, 13:11:46Subject: Re: Fw: the world as mathematical. was pythagoras rightafter all ?What do you think of Tegmark's version of a mathematical Platoia? --You received this message because you are subscribed to the GoogleGroups "Everything List" group.To view this discussion on the web visit https://groups.google.com/d/msg/everything-list/-/6WzRUmWbHY0J.To post to this group, send email to everyth...@googlegroups.com.To unsubscribe from this group, send email to everything-li...@googlegroups.com.For more options, visit this group at http://groups.google.com/group/everything-list?hl=en.--You received this message because you are subscribed to the GoogleGroups "Everything List" group.To view this discussion on the web visit https://groups.google.com/d/msg/everything-list/-/qXpWpOqHJRYJ.To post to this group, send email to everything-list@googlegroups.com.To unsubscribe from this group, send email to everything-list+unsubscr...@googlegroups.com.For more options, visit this group at http://groups.google.com/group/everything-list?hl=en.

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