Re: A mixture of time dilations and constrictions

[Pentcho Valev <pvalev@BAS.BG>]

Stephen Speicher wrote:

> On Fri, 27 Jun 2003, pvalev wrote:
> >      Processes characterized only by time dilation are
> > traditionally called "stationary". I would be grateful if
> > someone could give the definition of such stationary
> > processes and then describe some particular one.
>
> The phrase "Processes characterized only by time dilation are
> traditionally called 'stationary'" is much too vague and
> imprecise to convey meaning.  In a given inertial frame, a clock
> which is present at two contiguous events having the same spatial
> coordinates may loosely be thought of as being "stationary."

I am afraid it is the concept of stationary process that is much too
vague, as
you adimit above. Please give a straightforward definition of
stationary processes and then describe some particular one. Consider,
for instance, a clock's hand  rotating in the x'-y'-plane, and two
consecutive positions (events) of the tip of the hand. When and in
what sense can the two events be thought of being "stationary"? Or
does "stationary" apply only to clocks with immobile parts, as has been
suggested in sci.physics.relativity?
     If we somehow resolve the stationary-process problem, how shall we
deal with
countless non-stationary processes which are characterized by
various time dilations and constrictions? For instance, the movement of
the tip of the hand in the example above can be characterized by
either dilation (t'<t) or constriction (t'>t) in the primed system,
depending on
the position of the hand  at a given moment. The proof is easy -
I shall present it if needed.

Pentcho