Re: What Is _MOTION_?

From: The Ghost In The Machine (ewill_at_sirius.athghost7038suus.net)
Date: 11/16/04 

Date: Tue, 16 Nov 2004 17:01:03 GMT

In sci.physics.relativity, Daniel Weston
<daniel009@webtv.net>
 wrote
on Mon, 15 Nov 2004 15:34:16 -0800
<9644-41993CF8-316@storefull-3135.bay.webtv.net>:
> We all certainly hope that when AllYou comes back next time, after
> thinking further a bit, he will have learned to think and talk more
> clearly. It would also be helpful if he matured a bit. A mind is a
> terrible think to waste.
>

It makes little difference; clocks cannot measure time directly.
Even the atomic fountain clock has a fatal flaw.

Hopefully I can draw this, but if the cavity resonator is placed
at point A, a somewhat accurate measurement is possible.

But suppose it was placed at point B, instead?

A====> * (top of Cs-133 fountain)
          * *
B====> * *
         * *
         * *
         * *
        * *
        ^ v
     source sink

I can't draw worth a darn but one gets the idea, one hopes.
Presumably the source pressure can be adjusted to control the
height of the fountain (depending on local g) but I know very
little about the actual internal workings atomic clocks.

All clocks measure motion of something: a pendulum, a
vibrating quartz crystal, a VCO synchronized by a pulse of
Cs-133 photons from atoms in a known state.

Whether this flaw affects the ideal one calls "time", I don't know,
although I doubt it; other effects can be construed by
hypothesizing the Lorentz contraction. For instance, the
design of accelerators must take the Lorentz contraction
and the relativistic mass-gain into account, lest they malfunction.

Time is a useful tool, much like the meter. The meter isn't
exactly measuring length directly, either -- although for
most practical purposes it's not all that different.
However, for something moving faster than a snail, one cannot
use a meter stick; one instead uses such things as light rays.
This suggests a dichotomy: the "real rod length" versus the
"light-measured length", which is similar to kenseto's ideas,
with one important difference: there is no *actual dichotomy*,
and the real rod length is exactly the same as the light-measured
length, from the standpoint of the observer shooting the beams.

Change the observer, and the length changes. Time also changes.

It's a weird but very consistent concept, and has yet to be
invalidated by any experiment; it's also a direct result of the
fundamental postulate of SR: that lightspeed is the same everywhere.

One has to give up one or the other, and lightspeed is easy to measure. :-) 

-- 
#191, ewill3@earthlink.net
It's still legal to go .sigless.

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