Re: Models. predictions, physicallity, and observations

From: AllYou! (idaman_at_conversent.net)
Date: 03/01/05 

Date: Tue, 1 Mar 2005 10:01:12 -0500

I'm cogitating.

"jem" <xxx@xxx.xxx> wrote in message news:zx_Ud.89657$bu.65695@fed1read06...
> AllYou! wrote:
>
> > "jem" <xxx@xxx.xxx> wrote in message news:h7%Td.89049$bu.32479@fed1read06...
>
>
> >>I wasn't suggesting that the *concepts* of "space" and "time" are
> >>trivial, only that their definitions are trivial in comparison with a
> >>definition like "intellectual process".
>
> > I know what you meant, and it's still my position that whether or not they are to be
> > considered physical is not trivial.
>
> During the last 100 years Physics has abandoned the attempt to describe
> Nature as anything more than the phenomena Nature produces. Entities
> like "space", which are omponents of models created to imitate Nature.
> aren't presumed to exist outside the models (i.e. don't warrant
> characterization as physical).
>
> >>Sort of, but I don't think the "reality" of what's observed is generally
> >>questioned - probably the most popular view in Science these days is
> >>that observations are the *only* reality.
>
> > In ordered to avoid any philosophical debate, I'll go along with that.
>
> When discussing the role of Science - philosophical issues are unavoidable.
>
> >>And what exactly is the dividing line between external and internal
> >>influences?
>
> > Physicality. By external, I meant external to the mind.
>
> You've just replaced one vague concept with another (i.e. mind).
>
> >>If you subscribe to the idea that observations are the only reality,
> >>then "reliability of the model" is synonymous with "accuracy with which
> >>the model represents reality".
>
> > I don't want to get into semantics, I just don't want what I post here to be quoted
back
> > to me when I later state my true position. It's my position that we can never know
> > reality.
>
> So what do you mean by "reality"? If something is unknowable in
> principle, in what sense could it be considered an aspect of reality?
> That's why the prevailing view in Physics is that "measurable phenomena"
> and "reality" are synonymous.
>
> How do you know that you're not hypnotized? How do you know this
> isn't all just
> > a scheme to get you to believe a certain reality? Without getting into any of that,
I'm
> > simply saying that to decide is something is accurate, we need a basis of comparison,
and
> > if we have reality with which to compare our model, then why do we need the model?
>
> Science is concerned only with what's measurable. If your hypothesized
> hypnosis is detectable then it's part of reality. If not, it's not.
>
> > It's not a bone of contention of mine, but just for the record, I subscribe to the
notion
> > that we have no way of *knowing* *reality*, however, we can build a model which is
> > reliable in terms of its predictability. IOW, we assess the reliability of the
> > predictions. Again, I only made these comments as a backdrop to my overall point.
>
> Again the assumption Science makes is that there is no more to reality
> than the phenomena. Any aspect that has no associated phenomena is
> unknowable in principle, so what sense would it make to consider it an
> aspect of reality?
>
> >>How can we "delude" ourselves? We build mechanisms to tell us what's
> >>going to happen, and either it happens or it doesn't. In one case our
> >>mechanism is right (so far), and in the other case it's wrong.
>
> > It can be wrong in the explanations. Here's an example: I say that splat rays from
Mars
> > will cause this rock to hit the Earth when I release it. I release it. It hits the
> > ground. Have I demonstrated anything as to why the rock hit the ground? Did I
> > demonstrate the existence and/or the effects of spalt rays just because I wove an
> > explanation into the prediction?
>
> Science doesn't try to *explain* phenomena, only predict them. When
> it's said for example that "gravity" or "curved spactime" causes the
> rock and the Earth to come together, that's strictly a description of
> the behavior of entities within models, and the "cause" is logical in
> nature (i.e. is an inference based on some underlying assumptions), not
> physical.
>
> If you were to create a model that "explained" falling rocks using spalt
> rays, that would be fine. Of course, in order for it to be a viable
> model *all* the corresponding predictions based on spalt rays would need
> to agree with what's observed.
>
> > To say that we can predict how a clock will function, and that time is what a clock
says
> > it is, demonstrates nothing as the physicality, or as you would say, the reality of
time.
> > All we know is that what we observed of whatever process we've defined as a clock
behaved
> > as we predicted.
>
> You're looking at this issue from the wrong angle. Consider devices
> called thermometers that make measurements (i.e. produce numbers). The
> name "temperature" has been assigned to those measurements.
> "Temperature" isn't something that's presumed to exist, which
> thermometers have been created to measure. If it were it would make
> sense to ask the question "how do you know that thermometers measure
> temperature?", but it should be obvious that, if "temperature" is simply
> a name for the measurements, such a question isn't meaningful.
>
> It's the same with clocks and time. "Time" isn't something that's
> presumed to exist, which devices must be created to measure. There are
> devices called clocks (constructed in a prescribed manner) which make
> measurements, and "time" is just the name that's given to those
> measurements.
>
> >>So you don't like the answer "spacetime curvature causes clocks to lose
> >>time"? Why not? It's logical. Suppose a clock would register a
> >>certain elapsed time in a flat spacetime model, and suppose the elapsed
> >>time registered is reduced when the only change to the model is the
> >>introduction of a curved spacetime, doesn't it follow that the lost time
> >>is attributable to the curvature?
>
> > Not if the curvature is just an intellectual concept. IOW, let's say we construct a
graph
> > (i.e., a mathematical concept born in the mind) which is used to assist us with
> > quantification and predictions and the like, and then in order to assure that the
graph
> > remains valid, we *curve* it to remain consistent with predictions and observable
results.
> > Is it then valid to say that the results are caused by the curved graph?
>
> No. "Graph" is not an element of the model like e.g. "curved spacetime"
> is. A graph is a representation of a particular relationship between
> quantifiable entities - it doesn't make sense to talk about it having an
> effect on the entities.
>
> That's
> > backwards. The results are caused by something, but not a concept. The problem I
have is
> > that now that we've fooled ourselves into thinking we've actually answered a question,
we
> > move on. We forget the question. What *caused* the clock to *lose time*?
>
> There's no "fooling" going on. The "causes" of the lost time are the
> assumptions that logically lead to that result in the models that have
> been created to imitate clock behavior. Such causes aren't unique - the
> same model can be configured in a variety of ways, each of which will
> provide a different "explanation". However, explanation isn't the goal
> - prediction is.
>
> > Time is a mathematical concept.
>
> Only in the sense that "time" can be the interpretation of a variable in
> some mathematical theory. Of course, every measurement can be
> considered a "mathematical concept" in this sense.
>
> >>But Science doesn't misunderstand what space and time are - they're
> >>precisly defined in the models that use them (in the language of
> >>mathematics of course). The confusion is yours.
>
> > Maybe, but tell me how time is different than splat rays. Show me how time is
physical
> > such that it can't be confused as I've explained above.
>
> "Time" is a measurement - it's the physical representation that appears
> on a measuring device known as a clock. "Splat rays" are an
> "explanation" for measurements.
>
> >>You say there's a *clear* distinction between physical and conceptual.
> >>So what is it? It should be a rule that will permit the unambiguous
> >>classification of anything into one category or the other (or "none of
> >>the above").
>
> > That which is capable of affecting us (e.g., stimulating our senses), either directly
or
> > indirectly, is physical. As I explained, that was the whole goal of physics to begin
> > with.
>
> "Things that can stimulate senses" is all-inclusive. Everything that
> can be referred to has the potential to stimulate senses.
>
> >>Sorry, but you don't get to redefine the terms.
>
> > I, just like anyone else, get to challenge conventional wisdom of current definitions.
>
> There's no "wisdom" associated with definitions (other than "semantical
> wisdom"). Definitions sre simply word substitutions.
>
> >> The generally accepted
> >>definition of "counting" doesn't infer that the counter has to be aware
> >>of the underlying "meaning" of the process. If you want to draw such a
> >>distinction then you can invent your own word. E.g. "splatting" is the
> >>process whereby humans quantify with understanding and machines quantify
> >>without understanding.
>
> > But I didn't redefine anything. *Counting* is quantification, and the whole notion of
a
> > quantity is a concept born in the human mind.
>
> Yes, "counting" can be considered a quantification, but whether or not
> only human minds are capable of performing it is what we're trying to
> ascertain - so don't presume it.
>
> If a non-human "mind" can produce quantifications that are identical to
> those produced by humans, then it necessarily follows that the ability
> to count (i.e. quantify) isn't limited to human minds.
>

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