[.. The classic Einstein train scenario has two flashes and
    two observers, O=trackside-observer and P=trainboard-observer.
    The scenario involves three events: aleft-hand flash, aright-hand flash, 
    and P and O reach the same point.  All three are simultaneous in O's
    coordinate system, and the P/O crossing is located at a midpoint
    between the two flashes in O's coordinate system (and hence in
    all coordinate systems).

    Bill Owen then alters the scenario slightly. ..]

:::  wowen@extro.ucc.su.oz.au
:::   If the passenger is at a point just *prior* to the midpoint 
:::   when the flashes occur:
:::   He *could* see them as being simultaneous:
:::   (the observer, located equidistant from the flashes, will also 
:::   see them as being simultaneous however not necessarily at 
:::   the same *time* as the passenger).

:: throopw%sheol.uucp@dg-rtp.dg.com
:: Owen's mistake is due to the fact that the lightning strokes did not
:: occur at locations A and B in P's frame.  [...]
:: Which exactly ensures that P will not be at a midpoint between the
:: locations of where-the-flashes-used-to-be in any frame *but* O's; [...]

: terrycre@ix.netcom.com (Harvey Block) 
: Wayne, in these last two sentences I think you are in error.  Is this
: really what you intended to say? P *will* see them as simulteneous in
: Diagram 2 (assuming P is the right distance back when the lightning
: flashes), but this does not detract from the point that Einstein was
: making regarding Diagram 1. 

I still maintain that P does NOT "see them as" simultaneous.  Note the
distinction: one might say P "sees them simultaneously", since after all
the light pulses reach P simultaneously.  But in P's reference frame,
the flashes occured at different distances, and so the event of
"left-hand-flash" and "right-hand-flash" have a different
time-coordinate in P's coordinate system; they are NOT "simultaneous"
(which is just greek for "same time coordinate"). 

Remember the relationship between x coordinates, even in plain
old galilen coordinate systems:

       x' = x-vt

Specifically, whether we are talking SR or just plain old newtonian
mechanics, light coming from the left-hand flash covers more distance in
P's coordinates than light coming from the right-hand flash.  There's no
relativistic subtelty here; In O's coordinates, the two distances are
identical, but because of the -vt term, Owen's setup ensures the equal
distance occurs ONLY in O's frame.  Einstein's setup makes t=0, and so
the distances are equal in *all* frames. 

This is not just mathematical bafflegab.  It's to do with the physical
meaning of using P's or O's coordinates.  On O-coordinates, O is
motionless, and the train is rolling on the track.  In P-coordinates, P 
is motionless, and the track is sliding under the train.  And this physical
fact of relative motion is exactly what leads to the -vt term in converting 
x coordinates between P and O.  Note that this only makes the flashes
non-simultaneous for P when we presume all observers see an identical
lightspeed.

Or look at it this way, no math involved.  Draw O's worldline.  Then
draw P's worldline.  Now draw the O-flashpoint-worldlines in, parallel
to O, and finally the P-flashpoint-worldlines, parallel to P.  It is
then immediately obvious from such a diagram that in Owen's scenario, P
is not at a midpoint (in fact, is NEVER at a midpoint between the
P-flash-worldlines), so the light traveled different distances, so the
flashes aren't simultaneous.  Whereas in Einstein's scenario, P IS at a
midpoint, the light traveled the same distance, but reached P at
different times.    See such a diagram below.

    

The bottom line is, in both Einstein's and Owen's scenario,
in O's coordinates the flashes occur at the same time, 
and in P's coordinates the flashes do NOT occur at the same time
(given the observer independence of lightspeed axiom).
Any claim that the flashes occur at the same time in P's coordinates
for either scenario is incorrect.