On Mon, Jul 2, 2012 at 5:35 PM, meekerdb <meeke...@verizon.net> wrote:

> On 7/2/2012 2:09 PM, Jason Resch wrote: > >> >> >> To summarize our conversation up to this point: >> >> BM: Do you really not see any difference between tables and chairs and >> people and numbers, >> JR: Chairs and people are also mathematical objects, just really complex >> ones with a large information content. This is the necessary conclusion of >> anyone who believes physical laws are mathematical. >> BM: No, it's a necessary conclusion of anyone who cannot distinguish a >> description from the thing described. >> JR: I think the identity of indiscernibles applies: If no distinction can >> ever be made (by observers within a mathematical universe and observers >> within a physical universe) then there is no distinction. You are using >> "physical" as an honorific, but it adds no information. >> BM: I can point to a chair and say "This!" >> JR: Yes, but how do you know you are pointing to a "physical chair", >> rather than a "mathematical chair"? >> BM: I know I'm pointing at a chair. I don't know what at 'mathematical >> chair' is. Can you point out how it is different from a chair? >> >> I think we both agree that if the universe follows mathematical laws, >> then observers can make no distinction between whether they exist in a >> platonically existing mathematical object, or a physical universe. If you >> agree with this, then there is no fundamental ontological difference >> between chairs, people, and numbers, that I can see. >> > > No. The mathematical laws of physics (e.g. the standard model) leave > initial conditions undetermined, Which is equivalent to saying every solution to the Schrodinger equation is true. > they assume inherent randomness (symmetry breaking), No where in the math of quantum mechanics is there anything that suggest collapse of the wave function. A strict interpretation of the the math leaves only MWI (or alternatively, as Ron Garett points out zero-universes https://www.youtube.com/watch?v=dEaecUuEqfc ). The randomness is explained directly by first person indeterminacy in a reality containing all possibilities. > they don't specify why they are the laws of physics instead of some > others. Many physicists hope that they will one day find a reason that our laws of physics are unique, some justification why the one they find themselves in is the only one that can be, but this seeming to be a pipe dream. Many physicists dislike anthropic reasoning, perhaps because it spoils their dream of finding a TOE, but disliking something shouldn't carry any weight in assessing a theory's validity. > So the ontological difference is that some things exist and some don't. > This distinction doesn't exist in Platonia: exist=having a consistent > description. In physics exist=a member of the ontology of the fundamental > model. > What's wrong with Platonia being a fundamental model? > > That's why Everett, to avoid having some randomness, postulated that we > exist in many copies. I think there are more reasons than that. Before Everett, QM was extremely ugly, being the only non-local, non-time reversible, FTL permitting, theory in all of physics. It is more accurate to say Bohr and Heisenberg inserted collapse into the theory in an attempt to rescue the single-universe idea. There is nothing in the math of QM to suggest collapse exists, its addition was entirely artificial, and done to make the theory seem to fit in with our experience. Everett showed there was no need to do this to fit with our experience, as the theory itself explains why we don't feel ourselves split. > Others have postulated multiple copies of the universe beyond the Hubble > radius or in separate inflating spacetimes. Tegmark proposed "all > mathematical structures". Most of this strikes me as a metaphysical > stretch to equate the physical world with the Platonic. Why? > In Platonia everything not self-contradictory exists. There is no > difference between logical and nomological. Our universe is 'explained' by > anthropic selection from everything. And yet another mystery: fine tuning, is explained away. > So do you think there were chairs before there were people? Were there > numbers before people? > > There is no before or after in Platonia. Time is only meaningful to observers inside certain mathematical structures. > > >> Facing the question: is the universe a mathematical object, or a physical >> one, we must evaluate the two candidate theories as we would any other. >> > > That's not the question. The question is whether all mathematical objects > exist while only some physical ones do. No. If all mathematical objects exist, then all things which could be considered physical universes exist too. What possible difference is there between a physical universe and a mathematical structure isomorphic to that universe? Should these extraneous physical universes not be discarded according to Occam? > In the latter case we need to find which physical ones exist and what is > their mathematical description. > > > Does one theory explain more, does one make fewer assumptions, etc. The >> existence of the physical universe does not explain the existence of >> mathematical objects >> > > I think it does. See William S. Coopers "The Evolution of Reason". > > > "The formal systems of logic have ordinarily been regarded as independent of biology, but recent developments in evolutionary theory suggest that biology and logic may be intimately interrelated. In this book, William S. Cooper outlines a theory of rationality in which logical law emerges as an intrinsic aspect of evolutionary biology. He examines the connections between logic and evolutionary biology and illustrates how logical rules are derived directly from evolutionary principles, and therefore, have no independent status of their own. This biological perspective on logic, though at present unorthodox, could change traditional ideas about the reasoning process." Perhaps rules of logic exist in biology, but the full set of truth concerning the natural numbers is not contained in biology. > , but the converse is true. >> > > But only in the cheap sense of 'explain' like "God did it." Bruno at > least limits his fundamental ontology to digital computation, but even this > threatens to 'explain' too much. > > It is more powerful than "God did it". Given sufficiently powerful computers, we can verify predictions of the theory. Tegmark also believes we can test his theory by seeing statistically how well our universal constants fit within certain bounds necessary for life to exist. Jason -- You received this message because you are subscribed to the Google Groups "Everything List" group. To post to this group, send email to everything-list@googlegroups.com. 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