On Sun, Jul 24, 2011 at 8:14 AM, Stephen P. King <stephe...@charter.net>wrote:
> On 7/24/2011 12:05 AM, Jesse Mazer wrote: > > > > On Sat, Jul 23, 2011 at 11:24 PM, Stephen P. King > <stephe...@charter.net>wrote: > >> On 7/23/2011 9:45 PM, Jason Resch wrote: >> >> If you want to formulate block time without reifying spacetime, then >> just consider block time a collection of events separated by certain >> distances and directions from eachother. You may be right that ultimately >> this is all related to a theory of observation, and I think I can understand >> what you mean by relativity explaining the organization of these >> events/observations. In any case, a block universe seems to be a simpler >> theory than that of one in which objects become real and become unreal >> continuously, and it is consistent with observations. There is no >> scientific justification for presentism that I am aware of. >> >> Jason >> >> Hi Jason, >> >> But can't you see that I am arguing against any form of spacetime >> substantivalism, this includes block spacetime, block time, presentism ( >> http://en.wikipedia.org/wiki/Presentism_%28philosophy_of_time%29), >> eternalism ( >> http://en.wikipedia.org/wiki/Eternalism_%28philosophy_of_time%29), etc. >> The idea that events exist with specific properties attached independent of >> specification of measurement - of which observation by humans is a special >> case - is what I am arguing against. See: >> http://plato.stanford.edu/entries/spacetime-holearg/ for the full >> details. Substantivalism just a hold over of Aether theories. >> http://en.wikipedia.org/wiki/Aether_theories and I argue that it is an >> unnecessary hypothesis. >> One specific observation that for me nails substantivalism is the >> observation of no delay or polarization difference between ultra high gamma >> photons and gamma photons of lower energies from the same gamma ray buster >> event. Spacetime is show to be smooth at all energy scales, this is contra >> all theories that treat spacetime as some kind of substance. >> >> > Substantivalism doesn't treat spacetime as a "substance" in the sense of > necessarily being made up of discrete grainy bits (which is all that the > gamma ray prediction was meant to test, see > http://www.sciencedaily.com/releases/2011/06/110630111540.htm ), it just > says that spacetime has physical properties of its own, like the notion of > the different curvature at different points in spacetime which is present in > general relativity. See also the discussion of "sophisticated > substantivalism" on p. 9 of > http://www.st-andrews.ac.uk/~kjh5/OnlinePapers/MetaphysicsandRelativity.pdfand > also at > http://users.ox.ac.uk/~ball0402/papers/sheffield.pdf (the author also > apparently wrote a thesis about this and is in the process of writing a > book, see the bottom of the page at > http://users.ox.ac.uk/~ball0402/research/ ) > > -- > > Hi Jesse, > > To support my possition. From > http://www.sciencedaily.com/releases/2011/06/110630111540.htm : "Some > theories suggest that the quantum nature of space should manifest itself at > the 'Planck scale': the minuscule 10-35 of a metre, where a millimetre is > 10-3 m. However, Integral's observations are about 10 000 times more > accurate than any previous and show that any quantum graininess must be at a > level of 10-48 m or smaller." That pretty much blows up the idea of Plank > scale graininess! > First of all, it actually doesn't blow up all theories of grainy spacetime, only certain ones involving Lorentz violation due to graininess, see the comments by "unusualname" on this thread: http://www.physicsforums.com/showthread.php?t=511195 Second, even if it did rule out all grainy theories, why would you think this should "support your position"? I just got through saying that substantivalism does *not* imply graininess, it's quite possible to be a spacetime substantivalist in general relativity (indeed, I think this is the context of most modern discussions of substantivalism vs. relationalism) where spacetime is treated as totally smooth and continuous. > > The idea here is that the observables of QM map to the building block > of GR so that the relationship between the two theories is a duality; one > cannot be defined without the other. Similarly, observations cannot be > defined without observers, so the idea that spacetime is a substance that is > a 'bearer of properties" fails. Presentism fails as it is a form of > solipsism. Endurantism fails because it treats time and space as separate > and independent. OTOH, we can rehabilitate all three so long as we consider > QM system as observers. Each QM system has a set of observables that are > uniquely "real" to it (ala solipsism) and those observables are integrated > with those of other QM systems via requirements of mutual consistency of > observations; which is just another way of saying that the laws of physics > are the same for all. > I've never been able to understand what people mean when they talk about wholly subjective or observer-dependent interpretations of QM. What would define the "observables that are uniquely real" to a "QM system", if QM systems have no intrinsic properties themselves but are only defined by the observations of other "QM systems"? Your comment about mutual consistency suggests some idea of bootstrapping the properties of each individual system by finding a single self-consistent "world", but if something like that were possible (and this is all very speculative and handwavey if we don't have a mathematical theory of how it works) than each system *would* have a set of objective properties relative to the "world" it was part of, it seems to me. And why couldn't these properties include spatial or temporal relations? If you consider all the properties of different systems at different times (even if "time" is defined in a wholly relational way) to be equally "real" ontologically, then you still believe in a form of block time, the notion of block time doesn't presuppose spacetime substantivalism as Jason Resch pointed out earlier. Jesse -- 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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