On Fri, Jan 28, 2011 at 11:10 PM, Brent Meeker <meeke...@dslextreme.com> wrote: > On 1/28/2011 7:54 PM, Rex Allen wrote: >> On Fri, Jan 28, 2011 at 12:52 PM, Brent Meeker<meeke...@dslextreme.com> >> wrote: >>> On 1/27/2011 10:08 PM, Rex Allen wrote: >>>> On Thu, Jan 27, 2011 at 7:58 PM, Brent Meeker<meeke...@dslextreme.com> >>>> wrote: >>>>> But if the emulation attempts to be local then it must include >>>>> inherent randomness - which I think is not Turing computable. >>>>> >>>> >>>> The Turing machine could draw the required randomness from a tape of >>>> random bits, couldn't it? >>>> >>>> The question might then be asked: >>>> >>>> "Where did the tape of random bits come from?" >>>> >>>> To which I guess a response of sorts might be: >>>> >>>> "Well, where did the Turing machine come from? Probably from there." >>>> >>>> If you can have unexplained order, then you can have unexplained >>>> randomness, can't you? >>>> >>> >>> Sure, but then you've gone beyond Turing emulation. A tape providing the >>> random numbers would have to be a realized (not just potential) infinity. >>> >> >> Going beyond Turing emulation? Doesn't the definition of a Turing >> Machine involve infinite memory and and infinite tape? >> > > And infinite tape which is all blank except for a finite header.
So adding the random tape does take you beyond the standard Turing Machine...all the to Probabilistic Turing Machine. Not that long a journey, really. >> You believe that space-time is finite? >> >> You believe that there isn't an infinite causal chain behind us? You >> believe that there was a "first cause"? >> >> > > I think a "first cause" is probably incoherent. But the past could be > finite without there being a "first cause". Some sort of circular time? Or like Hawking's and Hartle's "no boundary" proposal? Even if you have some sort of closed causal loop, or an eternally existing space-time block, the question is still there...what caused this to exist, in the way that it does, instead of something else or nothing at all? Stephen Barr: "In fact, however, the requirement that there be no boundary is itself just a special kind of boundary condition among many others that are logically possible. As the Harvard physicist Sidney Coleman pungently remarked in the introduction of one of his technical papers, "Although the 'no-boundary' boundary condition may be pretty, it is not divinely ordained, and thus [we shall also] investigate alternative boundary conditions." Don Page: "Whether or not the Universe has a beginning has no relevance to the question of its creation, just as whether an artist's line has a beginning and an end, or instead forms a circle with no end, has no relevance to the question of its being drawn." And Hawking himself: "Even if there is only one possible unified theory, it is just a set of rules and equations. What is it that breathes fire into the equations and makes a universe for them to describe? The usual approach of science of constructing a mathematical model cannot answer the question of why there should be a universe for the model to describe." -- 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. 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.
