On Thu, Dec 20, 2018 at 1:25 PM Brent Meeker <meeke...@verizon.net> wrote:
> > > On 12/20/2018 1:38 AM, Jason Resch wrote: > > > > On Wed, Dec 19, 2018 at 5:51 PM Brent Meeker <meeke...@verizon.net> wrote: > >> >> >> On 12/19/2018 4:31 AM, Jason Resch wrote: >> >> >> >> On Wed, Dec 19, 2018 at 6:00 AM Bruce Kellett <bhkellet...@gmail.com> >> wrote: >> >>> On Wed, Dec 19, 2018 at 10:40 PM Jason Resch <jasonre...@gmail.com> >>> wrote: >>> >>>> On Tue, Dec 18, 2018 at 11:14 PM Bruce Kellett < >>>> bhkell...@optusnet.com.au> wrote: >>>> >>>>> From: Jason Resch <jasonre...@gmail.com> >>>>> >>>>> 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. >>>>> >>>>> But no dynamics. >>>>> >>>> >>>> I'm not sure what this means. Not dynamic in what sense? >>>> >>> >>> Dynamics is the study of matter in motion. There are no clocks in >>> arithmetic. >>> >> >> Matter only moves with respect to different times, likewise the state of >> a computer's registers and memory only change between steps of a CPU. You >> could study the dynamics of state changes in a computer. >> >> >>> >>> >>>> 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. >>>>> >>>>> >>>>> I do not have the time or inclination to rebut every argument that is >>>>> presented in arbitrary papers. But if you abandon the idea of >>>>> 'simultaneity' as used in this paper, the objections to the idea of "the >>>>> present" as a ourely local concept collapse. >>>>> >>>>> >>>> Then you have already abandoned the idea of a 3-dimensional space >>>> evolving in time. How does this not leave "block time" as the only view >>>> that preserves an objective global spacetime? Why give up an objective >>>> realist view that captures all of spacetime when you do't have to? >>>> >>> >>> In what sense has this given up an objective global spacetime? All that >>> has been abandoned is the concept of a universal time parameter which could >>> give unique sense to global time slices. One can imagine such a foliation >>> of space like hyper surfaces if one wants to, but it is not imposed by >>> relativity. >>> >> >> But relativity does rules out "naive presentism" -- the idea that there >> are is an objective spacelike hypersurfaces that we can call a present. You >> seem to agree with me on this. What I am struggling with is the >> interpretation of time, or of the present, when you reduce present moments >> to single points in space time. What does this buy you? It seems to make >> it much harder to talk about the *relationship* between remote points in >> space time. >> >> >> It's easy: They are spacelike, pastlike, or futurelike. >> > > But as you and Bruce have said recently, the present is not space-like, > but must be localized to a single point (or do you disagree with this?). > > > You referred to talk about *RELATIONSHIP* between points in spacetime. > Space-like is a *relationship* between two points (events). > So what constitutes the present, in your view? Is there such a thing? If so, what does it contain? > > > What dimensionality do you assing to pastlike and futurelike? > > >> >> >> For example, how do they effect one another? >> >> >> Each one is affected by those in its past light cone. >> > > A past light come is a space-time (4-d volume). This gets you back to the > Andromeda paradox (two observers crossing each other on the sidewalk share > different past and future light cones which contain different ontologies. > > > No, light cones are invariants. The two observers have the same past and > future lightcones as they pass on the sidewalk. > If the two observers are moving, then in the past they were in different locations, and belonged to different past lightcones. Their past (and future) lightcones would be at an angle to each other, would they not? Isn't it the case they will only share a past light cone if they are in the same location and have the same reference frame? > > > >> >> How can one talk about machines (such as our own brains) which are >> extended in space time, when we can only talk about individual atoms, or >> neurons existing in their own present, when they must interact with other >> neurons whose signal remains but that neuron now no longer exists (being in >> its own present time different from the perspective of the neuron which >> received its signal). It just seems so much more complicated to add the >> notion of popping into and out of existence, when it is wholly unnecessary >> and adds nothing to the theory. >> >> >> There's no problem with considering those events in the past light cone >> as affecting each event. >> > > Except when it comes to saying whether those things exist. > > > What's the problem with saying events in the past light cones exist, or > did exist? > > Nothing, my only problem is saying those things have stopped existing. > > >> >> >> >>> The problem with the "objective realist view" to which you seem to wish >>> to cling is that not only is it not required by SR, it is positively ruled >>> against by quantum mechanics, particularly non-local EPR-type correlations. >>> >> >> I don't agree EPR has any bearing on this topic, but also don't want to >> re-open that can of worms here. >> >> >>> >>> This reminds me quite a bit of the break down of the naive conception of >>>> personal identity. The normal view is each person's experiences are >>>> bounded by either psychological or biological continuity. Thought >>>> experiments such as duplicating or permuting minds show neither of these >>>> can work. The only consistent choices that remain are: >>>> 1. "universalism" -- all experiences belong to one universal experiencer >>>> 2. "no-self" -- there are only single individual thought moments >>>> >>> >>> Your person-duplicating thought experiments have no such drastic >>> consequences -- there are other possibilities. >>> >>> >> >> I would like to hear what they are, as I am not aware of them. >> >> >>> The thought experiments of relativity, such as the Rietdijk-Putnam >>>> experiment, lead to a similar break down. You either reduce what exists >>>> "presently" to a collection of independent events (points) in space time, >>>> or you expand it to include all of space time. But in both cases, you are >>>> saying what exists in the present is the same (all points in space time vs. >>>> all of space time). I'm not sure you there is really a conceptual >>>> difference. >>>> >>> >>> There are many presents. Each present is purely local. >>> >> >> So ontologically speaking, all that exists right now is what? >> >> >> There is "here and now". >> > > So a single Plank-length volume. (or if it is not a Plank-length volume, > please tell me how large the spatial extent of "here" is) > > >> There is "here and then". >> > > A past-light-line (not a cone?) > > >> There is "there and then" >> > > It doesn't/never existed? > > >> But there is no "right now". >> >> > So nothing exists but the current local Plank-time point? > > > You're just playing with words. There is no "right now" because the > concept has no definite reference. It doesn't imply that distant events > don't exist. > > Why can't "right now" refer to a slice through spacetime, and each observer in each reference frame can have a different conception of what the contents of "right now" includes? 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.
