On 7/24/2011 12:05 AM, Jesse Mazer wrote:

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On Sat, Jul 23, 2011 at 11:24 PM, Stephen P. King<stephe...@charter.net <mailto: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. JasonHi 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 senseof necessarily being made up of discrete grainy bits (which is allthat the gamma ray prediction was meant to test, seehttp://www.sciencedaily.com/releases/2011/06/110630111540.htm ), itjust says that spacetime has physical properties of its own, like thenotion of the different curvature at different points in spacetimewhich is present in general relativity. See also the discussion of"sophisticated substantivalism" on p. 9 ofhttp://www.st-andrews.ac.uk/~kjh5/OnlinePapers/MetaphysicsandRelativity.pdf<http://www.st-andrews.ac.uk/%7Ekjh5/OnlinePapers/MetaphysicsandRelativity.pdf>and also at http://users.ox.ac.uk/~ball0402/papers/sheffield.pdf<http://users.ox.ac.uk/%7Eball0402/papers/sheffield.pdf> (the authoralso apparently wrote a thesis about this and is in the process ofwriting a book, see the bottom of the page athttp://users.ox.ac.uk/~ball0402/research/<http://users.ox.ac.uk/%7Eball0402/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!`

`From`

`http://www.st-andrews.ac.uk/~kjh5/OnlinePapers/MetaphysicsandRelativity.pdf`

`<http://www.st-andrews.ac.uk/%7Ekjh5/OnlinePapers/MetaphysicsandRelativity.pdf>`

`we read:`

"2.2 Substantivalism and Relationalism

`Metaphysicians have long argued about whether space and time are`

`entities in their`

`own right, or whether they are mere abstractions from concrete objects`

`and events.`

`Could there be space and time if there were no objects and nothing ever`

`happened?`

`There is consensus that, given relativity, we can no longer talk about`

`three-`

`dimensional space and one-dimensional time, and must instead talk about`

`four-`

dimensional spacetime. But there is no consensus about whether GR favours

`substantivalism, the view that spacetime is a genuine entity, or`

`relationalism, the view`

`that spacetime is nothing over and above the events occurring in it.`

`(cross-ref chapter`

on space)

`As we have just seen, GR invokes the shape of spacetime itself to`

`explain why objects`

`move as they do, why the apple falls, why we can walk around on the`

`surface of the`

`Earth. Spacetime is no longer just an inert, neutral backdrop against`

`which objects`

`and forces interact, it is an element in that interaction. In this way,`

`GR points towards`

substantivalism about spacetime.

`Yet, as we shall shortly see, the 'hole argument' points in the opposite`

`direction,`

`indicating that substantivalists are committed to the existence of`

`physical facts which`

`go beyond anything required by GR. (In this respect, the hole argument`

`is like the`

`argument against presentism from the relativity of simultaneity,`

`according to which`

`presentists are committed to facts which go beyond anything required by`

`SR.)`

`Suppose you had to describe the room you're in right now. You could`

`describe the`

`various objects in the room, and then describe how they are related to`

`each other`

`('there's a monkey and a toy car, and the monkey is sitting in the`

`car'). Asked to`

`describe the whole universe, we could say 'there's a bunch of spacetime`

`points, they`

have such-and-such spatiotemporal arrangement, and matter and energy are

`distributed amongst them thus-and-so'. The bunch of points is the`

`'manifold', their`

`spatiotemporal arrangement is the 'metric', and the distribution is the`

`'matter field'.`

`GR tells us how the metric is related to the matter-field, how the shape`

`of spacetime is`

related to the distribution of objects.

`Now, how does the traditional substantivalism-relationalism debate`

`translate into`

`these terms? What do substantivalists affirm and relationalists deny?`

`Perhaps`

`substantivalists should claim that the manifold of points exists`

`independently of the`

events happening at those points, whereas relationalists should deny this.

`If substantivalists rashly accept this characterisation of their`

`position, then`

`relationalists can pounce. Suppose we have the manifold of points,`

`arranged with`

`their metric and their matter-field. Would things have been different`

`if the points had`

`been reshuffled, keeping the metric and the matter field constant? If`

`the points are`

`independently-existing entities, as substantivalists think, then`

`presumably any`

reshuffle makes a difference. But GR tells us that many reshuffles make no

`detectable difference at all. The points themselves don't seem to`

`differ in their`

`intrinsic properties: they don't have tiny labels that would enable us`

`to keep track of`

`them if they were switched around. So substantivalists are committed to`

`facts in`

addition to those recognized by GR -- facts about which points are where.

`(This criticism of substantivalism is known as the 'hole argument'`

`because, as a`

`special case, the points in a given region -- known as the 'hole' --`

`could be reshuffled`

without affecting what happens before, after or around that region.)

`/Substantivalists need to reconsider what they are substantivalists`

`about. If they take`

`spacetime to be just the manifold, the bare collection of points, they`

`will be`

`committed to undetectable facts, but they may be on safer ground if they`

`take`

`spacetime to be the manifold together with the metric, i.e., the`

`collection of points`

`together with the way in which they are arranged with respect to one`

`another. If this`

`more complex entity is replaced by an alternative manifold-plus-metric,`

`this would`

certainly make an empirical difference. / What sort of entity is a manifold-plus-metric? Different 'sophisticated

`substantivalists' have developed this idea in different ways, but one`

`option is to think`

`of each spacetime point as having its relations to other points`

`essentially, so that the`

points exist together in a web of mutual dependence. It seems clear that substantivalists can escape the hole argument in this way.

`What's not so clear is whether sophisticated substantivalism is really`

`distinct from`

`relationalism. /The more that GR gives a quasi-causal, dynamical role to`

`the`

`manifold-plus-metric, the more difficult it is to draw a line between`

`material things`

`(which relationalists accept) and spacetime itself. What's so special`

`about the`

`spatiotemporal properties of a point, in contrast to its other`

`properties, like those`

which fix how much mass or charge is there? Why think the spatiotemporal

`properties of a point are essential to it, whilst its other properties`

`are not? /"`

(the italics are mine to highlight important sections)

`I agree with this argument completely but go further! In my`

`thinking a manifold and metric do not have specific properties`

`independent of observers in the same way that physical objects do not`

`have specific properties independent of observers. Please correct the`

`following if I am wrong.`

`Crudely sketched: A manifold is made up of a patch work of "charts"`

`or coordinate systems sewn together by mapping functions that identify`

`certain points of one with certain points of the other. Forgive me if I`

`use the wiki articles for brevity sake. See:`

`http://en.wikipedia.org/wiki/Manifold,`

`http://en.wikipedia.org/wiki/Metric_tensor and`

`http://en.wikipedia.org/wiki/Tangent_space .`

`What if we can define the charts in terms of the particular`

`position and duration observables that some large collection of QM`

`systems have?`

`A metric defines a notion of distance on the manifold and is`

`derived by how a set of orthogonal vectors changes or remains the same`

`along points of a curve on the manifold. To be precise, let me quote the`

`wiki article on metrics: "In differential geometry`

`<http://en.wikipedia.org/wiki/Differential_geometry>, one considers`

`metric tensors <http://en.wikipedia.org/wiki/Metric_tensor>, which can`

`be thought of as "infinitesimal" metric functions. They are defined as`

`inner products <http://en.wikipedia.org/wiki/Inner_product> on the`

`tangent space <http://en.wikipedia.org/wiki/Tangent_space> with an`

`appropriate differentiability`

`<http://en.wikipedia.org/wiki/Differentiability> requirement. While`

`these are not metric functions as defined in this article, they induce`

`metric functions by integration`

`<http://en.wikipedia.org/wiki/Antiderivative>."`

`The key is the tangent space. "In differential geometry`

`<http://en.wikipedia.org/wiki/Differential_geometry>, one can attach to`

`every point /x/ of a differentiable manifold`

`<http://en.wikipedia.org/wiki/Differentiable_manifold> a *tangent`

`space*, a real vector space <http://en.wikipedia.org/wiki/Vector_space>`

`which intuitively contains the possible "directions" in which one can`

`tangentially pass through /x/. The elements of the tangent space are`

`called *tangent vectors* at /x/."`

`We can think of a tangent space as a set of possible directions`

`that a vector located at each point of a chart. In that sense tangent`

`vectors seem to be similar to momentum if their length are allowed to`

`vary as d/dx. My thought is that the relationship that we see in`

`canonical conjugates, say position and momentum is the same as points on`

`a chart and the vectors on the tangent spaces of that chart. The same`

`would hold for energy and duration (not time!) How this works for spin`

`is beyond my ability to put words together in English...`

`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.`

`From http://users.ox.ac.uk/~ball0402/papers/sheffield.pdf`

`<http://users.ox.ac.uk/%7Eball0402/papers/sheffield.pdf> we find:`

"Substantivalists understand the existence of spacetime in terms of the existence of its pointlike parts, and gloss spatiotemporal relations between material events in terms of the spatiotemporal relations between points at which they occur. Relationists will deny that spacetime points enjoy this robust sort of existence, and will accept spatiotemporal relations between events as primitive. (Belot and Earman, forthcoming)"

`Here I disagree with both substantivalist and relationists! Neither`

`spacetime points nor spatiotemporal relations are taken as "primitive"`

`but instead are emergent from a continuous interplay between QM systems.`

`I see QM systems as equivalent to Leibnizian Monads including the`

`property that they are "windowless" - they cannot 'exchange substances`

`with each other. All appearances of interactions flow via residuations`

`as explained by Vaughan Pratt here:`

`http://boole.stanford.edu/pub/ratmech.pdf`

`The basic idea of residuation works from a dynamic, as opposed to`

`static, interpretation of the Stone duality between logical algebras and`

`topological spaces.`

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