Re: Define a clock
From: AllYou! (idaman_at_conversent.net)
Date: 10/15/04
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Date: Fri, 15 Oct 2004 10:17:36 -0400
"jem" <xxx@xxx.xxx> wrote in message news:ClQbd.28485$UA.11230@lakeread08...
> AllYou! wrote:
> > "jem" <xxx@xxx.xxx> wrote in message
news:LD9bd.25587$UA.23283@lakeread08...
> >
> >>AllYou! wrote:
> >>
> >>>"jem" <xxx@xxx.xxx> wrote in message
> >
> > news:nnQad.22908$UA.19964@lakeread08...
> >
> >>>>AllYou! wrote:
> >>>>
> >>>>
> >>>>
> >>>>>"jem" <xxx@xxx.xxx> wrote in message
> >>>
> >>>news:y6xad.22452$%x.19646@okepread04...
> >>>
> >>>
> >>>>>>AllYou! wrote:
> >>>>
> >>>>>>>"jem" <xxx@xxx.xxx> wrote in message
> >>>
> >>>news:atR9d.21144$UA.21034@lakeread08...
> >>>
> >>>
> >>>>>>>>AllYou! wrote:
> >>>>
>
> >>So basically "time" is just a substitute for "the relatively precise
> >>position of the Earth relative to the sun as it moves" (since it's
> >>easier to ask for).
> >
> >
> > Not really. First of all, most people don't give any thought to whether
or
> > not *time* is real. All they care about is how one event relates to the
> > present. Insofar as my assertion that time is not a real preperty of
> > nature, there's a difference between the terms *time* and what *time it
is*.
> > Just because they use the same word does not mean that they're in any
way
> > the same.
> >
> >
> >>Well then, if "the relatively precise position of the Earth relative to
> >>the sun as it moves" is something observable and real, and if "time" is
> >>just a shorthand way of saying all that, doesn't that imply that "time"
> >>is observable and real?
> >
> >
> > Not in the context in which you asked the question in the first place.
If
> > the word *time* were used in the same sense in which I gave my answer to
you
> > (i.e., simply as a substitute for a much less convenient to describe
> > reality), then the answer to your question would be yes. Unfortunately,
> > many people consider time to be a real property of nature and in that
sense,
> > the answer to your question is no.
> >
>
> Right - "time" (like "distance") has different meanings in everyday
> language. When you're asked for the time, you're being asked for a
> particular measurement that's made by a measuring device called a clock,
> and in this sense "time" *is* a measurement made by a clock (analogous
> to "distance" *is* a measurement made by a ruler). Clearly then, this
> "time" is observable (as you've indicated above).
>
> However, "time" is also used to represent the entity which clocks
> measure (analogous to space being the entity which rulers measure), and
> when "time" is used in this sense, you're suggesting it's unobservable.
I'm suggesting that it's just a concept invented by man. We need it as a
tool in order to conveniently discuss the order of events. Time is only
observable in the sense that we use it as a substitute for comparing the
relative positions of all particles of matter at one point along their
respective paths to other points along their respective paths.
> >>>>Sure, there could be lots of motion internal to such a device, but
> >>>>suppose the blinking light is emitted by a single point-like particle
> >>>>that's relatively stationary to you the observer. In that case what
> >>>>would you be observing?
> >>>
> >>>
> >>>Relatively stationary?
> >>
> >>not moving relative to you
> >>
> >>
> >>>You'll have to be more specific as to what you're
> >>>hypothetical really entails. What is a single point particle? Does
> >
> > this
> >
> >>>particle have any size whatsoever? How does it blink? Does it emit
> >
> > light?
> >
> >>Does the observability of time depend on these details?
> >
> >
> > I don't know how to answer that question because it's my contention that
> > time is not observable. Therefore, the observability of time depends
upon
> > nothing.
> >
> >
> >> Can't you
> >>conceive of pulses of light emanating from a single location?
> >
> >
> > Not without something at some level happening which would cause that
light
> > to be emitted. What you call details may very well be what supports my
> > assertion. IOW, the blinking light is not magically emitted. Something
is
> > happening on some level, even if it's sub-sub-sub atomic, which entails
> > motion of some type. To ignore this *detail* which is the basis of my
> > assertion and then claim that it's not valid makes no sense.
> >
> >
> >>>Does the light have a wavelength? Does that wave travel any distance?
> >>
> >>The light is what makes you aware that something has occured at the
> >>light source. It needn't be light of course, any signal would do.
> >
> >
> > And any signal did not just magically appear. If it did, then time
might in
> > fact be real. But no event of any type is independent of motion except
for
> > those we imagine.
>
> So time isn't real because it's not possible to observe Nature except
> via the reception of some sort of signal?
For something to be a natural property of nature, there surely must some way
to observe it's existence or the effects of it's existence. In the case of
*time*, we observe motion, we call certain things in motion clocks, we say
that these things measure time, and then we use these motions as evidence
that time exists. It's completely circular.
> OK instead of a blinking light, suppose you're listening to your watch
> ticking, what is it that you're observing? (i.e. not a description of
> the physical processes you think are causing you to hear the sound, but
> simply what is it that you're perceiving)?
I'm observing the effects (sound) of the parts of my watch which are in
motion. I'm observing the sound this motion emits. IOW, I'm observing
clusters of particles of matter as they move from one point in space along
their path at some velocity to another point in space. That's the tall and
the short of it.
> >>>>>When the Big Bang occurred, among other fundamental properties of
> >
> > nature
> >
> >>>>>which came into being at that instant or in the milliseconds
afterward
> >>>
> >>>were
> >>>
> >>>
> >>>>>the weak and strong forces, gravity, mass, temperature, space, and
> >>>
> >>>velocity.
> >>>
> >>
> >>>>How about change in velocity, and change in change of velocity, and
...?
> >>>
> >>>
> >>>How about it? What's your question?
> >>>
> >>
> >>Well, shouldn't this infinite collection of motion descriptors be added
> >>to the list of fundamental properties of nature?
> >
> >
> > The changing value of a property is a property? We're getting into
> > unecessary semantics here but I'm willing to play if you want to explain
> > your point.
>
> Well if change in velocity (for example) isn't a fundamental property of
> Nature, then presumably it can be derived from the fundamental
> properties you listed. Which ones?
A change is not a property. A change is something which is caused by or is
affected by a property. A change in velocity of a mass is due to the
application of a force upon that mass. But what has this to do with the
issue at hand?
> >>>>And you should really use a different word to represent this
fundamental
> >>>>aspect of motion that you've labeled "velocity", since that term
already
> >>>>has a specific meaning as the rate of change of distance wrt (with
> >>>>respect to) time. Suppose we add an underscore to the start of the
word
> >>>>that refers to the fundamental version.
> >>>>
> >>>>So tell me, how do you propose to measure _velocity?
> >>>
> >>>
> >>>As we do with all other fundamental properties of nature. How do we
> >
> > measure
> >
> >>>distance? We take a quantity of distance, give it a name (unit), and
> >>>establish it as a standard by which all other distances will be
> >
> > compared.
> >
> >>>The same with velocity. Take a fixed quantity of it (as best we can)
> >
> > like
> >
> >>>the rotation of the Earth, assign a unit to it, and use it as the
> >
> > standard
> >
> >>>by which all other velocities will be compared.
> >>
> >>I suppose we could pick a location on Earth and take its _velocity
> >>(relative to what?) as our standard, but how do I go about comparing
> >>that _velocity to mine when I'm out jogging?
> >
> >
> > The parenthetical question.......*relative to what*.......is a
non-issue.
> > When you establish an inch as a unit of distance, the very definiton of
> > establishing a unit is to establish a standard for comaprison. It is
that
> > to which other distances will be compared. The same is true of a
velocity.
> > The whole reason why all of this misconception about *time* came to be
is
> > that there is no convienent way to carry around a fixed quatity of
velocity.
> > We can carry a unit of distance and a unit of mass, but doing so for
time is
> > difficult. What's more, comparisons of different velocities is even
more
> > difficult. But these difficulties only serve to further explain how our
> > dependence upon the concept of *time* came to be. It certainly does
nothing
> > to advance the case that it's real.
> >
> >
>
> this one's in a separate thread now.
>
> >
> >
> >>>>If something changes state or direction, doesn't that change have a
> >>>>beginning (i.e. a demarcation between not changing and changing)?
> >>>
> >>>
> >>>Yes it does, but an instantaneous change in direction of any mass would
> >>>require an infinite amount of energy and so none of these changes will
> >
> > be
> >
> >>>instantaneous.
> >>
> >>Of course that implies that circular motion (for example), where
> >>direction continuously changes, is impossible.
> >
> >
> > And had you put my response in context with your question as to change
of
> > direction having a beginning, you'd see that circular motion was
excluded
> > from the scope of both the question and answer.
>
> Why is that? Even circular motion has to have had a beginning.
And at the point where a particle began it's cirular motion, there was no
*continuous change* in direction and so we're right back to where I started
which is this point where a particle began it's circular motion is an event.
The very definiton of the begining of that circular motion is a discontiuous
change in direction. Look, we can debate these semantics all day. You
posed the issue of circular motion as in the context of it's current
existance, but now you change back to how this motion began at some point
earlier. I assume you have a point with all of this?
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