Re: what is the relation between force and energy?

From: TomGee (lvlus_at_hotmail.com)
Date: 10/20/04 

Date: 20 Oct 2004 05:38:11 -0700

greenfield_7@hotmail.com (Jim Greenfield) wrote in message news:<3c4afb26.0410182049.23fa2d8d@posting.google.com>...
> srp@microtec.net (Andr? Michaud) wrote in message news:<562f286c.0410181315.4af01835@posting.google.com>...
> > > > >
SNIP
> > > I understand that a sensitive gravity meter could detect my presence
> > > ref the fridge to my right; that force (me to fridge) is at 90 degrees
> > > to earth's center.
> >
> >
Yes, but only if gravity applies exactly parallel at that distance
from the source. A force measured from the center of the Earth would
be a force considered to be applied radially and by the time it got to
the floor of your penthouse, its lines of force could not be parallel.
 OTOH, I was taught that the lines of force of the Earth at its
surface apply parallel to objects there.

>
> And TIME is LONG. Even if this change in gravity IS so small, over
> such long time spans (of clocks running at different rates due to the
> strength of grav field), after billions of years, where is the
> evidence?
> >

Good question, but we cannot ever measure this evidence because we can
do so only from our own time rate, and because we cannot know the
actual age of objects in motion at rates different than our rates.
Time dilation is a mystery which is explained by more than the one
example of the Twin Paradox, so maybe it can be found clearer (and
believed in more easily) with another example. I post here an excerpt
from an essay I wrote of another example which is so evident of time
dilation that it defies contradiction.
"Part Two
        In a common textbook example of Special Relativity theory, two
observers - one of whom is seated inside a moving passenger train
while the other is standing outside watching the train pass by - take
accurate measurements with their own accurate clocks of the time it
takes light to travel from a ceiling lamp to the floor of the train
car. The experiment proves (in a surprising conclusion), that time
passes slower for the observer riding on the train, but only in
comparison to the rate of the passage of time for the other observer
standing alongside the railroad tracks. That doesn't seem right, how
can an experiment prove such a thing, and why does it apply only to
the two observers? It can do so by having the only relevant
difference between the two observers being that they are not moving at
the same speed.
        From the viewpoint of the outside observer who took his measurement
as the train went by, the light traveled "distance x" in moving from
the ceiling to the floor, plus "distance y," which is the distance the
train moved in the time it took for the light to travel to the floor
of the car. A line tracing the path of a single light particle as it
fell would show a diagonal line of travel drawn downward and curving
in the direction of the train's movement. For the observer in the
train, however, the light particle traveled only as far as "distance
x" because the train was not moving past relatively to her, since she
was on the same train as the light she meas-ured. For the train
rider, then, a line drawn based on her observation would be a simple
vertical one because she is moving along inside the train with the
photon as it falls. Thus, there is no "distance y" involved in her
measurement.
        In comparing the length of the two lines, the diagonally curved line
is longer, meaning that it had to have taken more time for the light
to reach the floor, as far as the stationary ob-server is concerned,
but less time than that as it pertains to the measurements of the
moving observer. If for the stationary observer the event took, e.g.,
two seconds to occur by his clock, and if for the train passenger it
took, say, only one second to occur by her clock, it means that in
this bilateral relationship, time passed for the stationary observer
at twice the rate that the train passenger underwent, and therefore he
aged faster, or more, than the passenger in the moving train. This
experiment clearly illustrates the time and motion relationship of
inverse proportionality in that the observer moving relatively faster
than the stationary observer ac-crued and underwent a slower time rate
than the stationary observer.
        This is an instance where we have obtained two accurate but different
time measure-ments of the same event; yet, this hardly seems possible.
 The speed of light is constant; so it could not be that which changed
and caused the difference in the time measurements, verdad? If the
speed of light did vary in order to accommodate the situation, that
would explain the time differences and we could then say that the
speed of light "warped" or "adjusted" to that particular situation,
since it would hardly seem possible that the rate of the passage of
time could change.
        If it was the case that the speed of light varied instead of the rate
of the passage of time (as opposed to just the passage of time), then
time would be a property of the universe, and if that was so, it seems
all objects in the universe should age at the same rate. If it is not
the case that the speed of light varied during the experiment,
however, it seems then that the rea-son for the time differences must
indeed have to do with the fact that the measurements were made while
each observer was in a different state of motion compared to the
other, and so the rate of time varied for each observer inversely
proportional to their particular state of motion. Up to this point,
many already agree with the latter case, as we shall see below.
        Within the context of Einstein's time-space interdependence premise,
(which is a con-clusion adopted to explain the time differences based
on the conviction that the speed of light can not vary) it is said
that both time and space must at some unknown point warp, fold, flex,
bend, dilate, or curve so as to reconcile the differences in the rates
of the passage of time as measured by our two observers. Beyond that
context, however, it is extremely difficult if at all possible to
apply such physical terms to time and space because neither can be as
easily studied as discrete objects. If we think that the rate of the
passage of time (or, the rate of ag-ing) is universal, that is to say,
if we think that time is, or is part of, a medium or "continuum" in
which all things are held equally "captive" - and are thus held
equally subject to its immuta-ble flow - then it becomes necessary
indeed to invent such terms as time and space "warps" when confronted
with such natural inconsistencies of the type shown in the experiment
above.
        On the other hand, if we agree that in our experiment above, the rate
of the passage of time varies for the observers due to the difference
in the states of motion between them, it is easier for us to think
from then on that the reason for the time differences is because each
ob-server measured the event from within a time rate corresponding to
his or her own state of motion. Remember that both measurements in
our train example are accurate and, essentially, the only difference
is that one observer is moving faster than the other at the instant
that they each measure the light traveling from the ceiling to the
floor inside the train car...."
TomGee 102004

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