On Wed, Dec 19, 2018 at 11:42 PM Brent Meeker <meeke...@verizon.net> wrote:
> > > On 12/19/2018 3:16 PM, Jason Resch wrote: > > > > On Wed, Dec 19, 2018 at 4:47 PM Brent Meeker <meeke...@verizon.net> wrote: > >> >> >> On 12/18/2018 6:34 PM, Jason Resch wrote: >> >> >> >> On Tue, Dec 18, 2018 at 7:27 PM Bruce Kellett <bhkellet...@gmail.com> >> wrote: >> >>> On Wed, Dec 19, 2018 at 12:19 PM Jason Resch <jasonre...@gmail.com> >>> wrote: >>> >>>> On Tue, Dec 18, 2018 at 6:45 PM Bruce Kellett <bhkellet...@gmail.com> >>>> wrote: >>>> >>>>> On Wed, Dec 19, 2018 at 11:27 AM Jason Resch <jasonre...@gmail.com> >>>>> wrote: >>>>> >>>>>> On Tue, Dec 18, 2018 at 6:05 PM Bruce Kellett <bhkellet...@gmail.com> >>>>>> wrote: >>>>>> >>>>>>> On Wed, Dec 19, 2018 at 11:02 AM Jason Resch <jasonre...@gmail.com> >>>>>>> wrote: >>>>>>> >>>>>>>> On Tue, Dec 18, 2018 at 3:23 PM John Clark <johnkcl...@gmail.com> >>>>>>>> wrote: >>>>>>>> >>>>>>>>> >>>>>>>>> Arithmetical computations don't change so there can't be a >>>>>>>>> correspondence between them and the evolution of spacetime or >>>>>>>>> with anything else that can change. >>>>>>>>> >>>>>>>> >>>>>>>> "y = 2x+1" defines the arithmetical relation of "oddness". >>>>>>>> >>>>>>>> Solutions to this equation yield (compute) for *y* all possible >>>>>>>> odd numbers. *y* changes with respect to increasing values of *x*, >>>>>>>> just as John Clark's brain changes with respect to increasing values of >>>>>>>> *t*. >>>>>>>> >>>>>>> >>>>>>> How does 'x' change? >>>>>>> >>>>>> >>>>>> With respect to y, and vice versa (like your brain state and your >>>>>> location in spacetime). >>>>>> >>>>> >>>>> Poor analogy. Change in the physical world is governed by dynamics, >>>>> described by equations with a veritable 't', called time. Time is probably >>>>> only a local phenomenon, but I do not see any 'time' variable in >>>>> arithmetic. >>>>> >>>> >>>> It depends on the equation. >>>> >>> >>> What equation? There are no dynamics in arithmetic. >>> >> >> There are computations. >> >> >>> >>> >>>> The analogy with the block universe idea is useless, because the block >>>>> universe idea is only a picture, not a reality. Special relativity merely >>>>> abolishes any notion of Newtonian absolute time, it does not prove that >>>>> all >>>>> instants of time are equally and simultaneously existent. The whole notion >>>>> of simultaneity is abolished in relativity. Minkowski's block universe was >>>>> a response to this, but not a very good picture in the final analysis, >>>>> because it completely fails to capture the local dynamical aspect of the >>>>> time variable. >>>>> >>>> >>>> Did you read https://core.ac.uk/download/pdf/11921131.pdf ? >>>> >>> >>> No. Why should I? >>> >> >> Because you believe relativity cannot be used to justify the block >> universe concept. >> >> >> You still won't believe it after reading the paper. It's full of >> falacious reasoning drawing conclusions about simultaneous events at >> different places instead of noting that simultaneity is meaningless for >> spatially separated events. >> >> >> > Simultaneity is only meaningless between different reference frames. > > > You mean an imaginary rigid frame that extends across the universe, which > assigns four coordinates to each event with values that cannot be > operationally determined in any way? > > Conventionally speaking, an observer's view of the present is the 3-d surface of a slice through spacetime perpendicular to their velocity through spacetime (at least it is using Euclidean coordinates, in which one's velocity through spacetime is always c). > There is no spacial limit on how distant the present moment can be > defined, once you assume a reference frame. > > > "Defined"? How is the defined value to be arrived at? How can it be > operationally determined? > It's defined the 3-d slice through spacetime, relative to your reference frame. Note: this isn't the view I suggest, this is just how the present moment is normally considered under special relativity. But this makes clear that the notion of an objective present is meaningless. So the ontology of only one 3-d slice existing is doomed. > > That two adjacent observers, in different reference frames, can have a > completely different (yet fully valid from their own POV) conception of the > present suggests that the naive view of an objective present is fallacious. > > > They can't have different conceptions of the present at their shared > location, they can read the same clock. It is only their imaginary > extension to some immeasurable "frame" that is fallacious. > > How is it imaginary if they later confirm it? i.e., they wait 1 year, and compare their readings from telescopes of things 1 ly away from them, and when they compare notes each one confirms that indeed their presents contained a different set of objects on that day 1 year ago when they crossed paths. > > > >> >> >> >>> >>> >>>> What is your interpretation of the >>>> https://en.wikipedia.org/wiki/Rietdijk%E2%80%93Putnam_argument ? >>>> >>> >>> The "present" is a local concept which cannot be extended to global >>> hyperplanes. >>> >> >> Which would means there is no such thing as a present point in time. >> >> >> I don't know what you mean by "in time". Every event can be labeled by >> four coordinate values one of which is "time", but the coordinate label is >> not the same as the clock reading of an observer at that event, and which >> defines that "present" for that observer. >> > > The present is everything an observer can conclude to exist at any > particular clock time. If he receives light from the sun at time (t+8 > minutes), he can conclude the sun existed at time t. > > > Yes, along his past light cone. Light cones are invariant structures which > are physically meaningful. > > Don't the two observers crossing paths share different past light cones (even if they are crossing at the same point?) Jason > > >> >> >> >>> Remember, the only sensible definition of "time" is an operational >>> definition -- "time is what is measured on a clock". This is a purely local >>> concept. >>> >> >> So then you have reduced the present to a point in spacetime, a single >> event. >> >> >> Nonsense. An observer can read his clock at every event along his world >> line. >> > > Then it would be a worldline that exists, which spans times (block-time), > rather than saying only a single moment in time exists (presentism). > > > The worldline doesn't span "block time", it spans clock time along the > worldline...which is different for different paths between two events (c.f. > twins paradox). > > Okay. So this worldline is like a string through spacetime? > > >> >> >> >>> >>> >>>> Do you agree in principal, that human experience of a dynamically >>>> evolving universe cannot be used to decide between block time and >>>> presentism? >>>> >>> >>> Special relativity certainly cannot be used to justify the block >>> universe concept. >>> >>> >> That wasn't my question. Do you believe your experience rules out the >> block universe? >> >> >> If you mean a pre-determined universe, I think that is ruled out by >> quantum randomness. >> > > The Shrodinger equation is deterministic. Quantum Randomness, like a > moving present, is a subjective phenomenon. > > > That's your theory. > It was Shrodinger's theory. Later in his life he came to believe his equation was true at all times and led to many-worlds. > You asked what was ruled out by *experience*. > > Direct experience doesn't let us decide between many worlds and collapse. So our experience cannot rule out a completely static fully determined past and future. Jason -- 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.
