On May 7, 7:17Â*pm, rbwinn wrote:
On May 7, 3:57Â*pm, " wrote:



On 7 mayo, 18:38, rbwinn wrote:

On May 7, 12:54 pm, " wrote:

On 7 mayo, 14:34, rbwinn wrote:

On May 7, 10:40�am, " wrote:

On 7 mayo, 12:25, rbwinn wrote:

On May 7, 8:06 am, PD wrote:

Well, no, if lightining strikes the front and rear of a moving train,
leaving marks on the train and the track, the marks on the track will
be the length of the train apart, which relativity of simultaneity
cannot explain. �According to mathematics, if the bolts of lightning
are simultaneous in the frame of reference of the track, the marks on
the track will be closer together than the length of the train; if the
bolts of lightning are simultaneous in the frame of reference of the
train, the marks on the track are further apart than the length of the
train. �Reality shows that the marks on the track will be the length
of the train apart, disproving this false teaching of Einstein..
Robert B. Winn

Nonsense. That is a bunch of words salad. What in the world those
marks you mention have to do with relativity of simultaneity?
This shows you have not read anything about SR. What does it mean
"according to mathematics"? And where does Einstein say the nonsense
of the marks on the track?
There are two events (the strikes) and two observers. What these
observers see is the light signal information that tells them about
the occurrence of those strikes. That is the reason one of them can
certify "I saw both strikes to be simultaneous", while the second
certify "I saw the front strike occurring before the back strike".

Einstein was the one who thought of the train and two bolts of
lightning. Â*He did not fully consider the mathematics of the situation
he described. Â*Einstein did not say anything about marks on the track,
but I did. Â*The marks on the track prove that relativity of
simultaneity cannot exist in reality. Â*Lightning hits the front and
rear of the train simultaneously as seen by an observer by the track,
leaving marks on the front and rear of the train and marks on the
railroad track. Â*The distance between the marks on the train is the
length of the train. Â*The distance between the marks on the track is
the length of the train. Â*In order for relativity of simultaneity to
exist, the marks on the track would have to be closer together than
the length of the train. Â*Conversely, if the bolts of lightning are
seen simultaneously by the observer on the train, in order for
relativity of simultaneity to exist, the marks on the track would have
to be further apart than the length of the train. Â*Reality shows that
the marks on the track are the length of the train apart.
Robert B. Winn

That is complete nonsense. What Einstein wrote about this subject,
just for people like you, can be seen inhttp://www.bartleby.com/173/9.html
Observers do not have to measure any length (actually it would be very
tough to measure a 200000km train, not speaking of how to build it and
how to place the tracks). The only requirement is for the observers to
coincide at t=0 at x=0, that the strikes occurred at x=-X0 and at x=
+X0 and that the train with its observer is moving at a speed v into
the +x direction.
The observations consist of both observers receiving the light signals
that communicate them of the strikes occurrence. Where in the world
are you seeing something related to measuring lengths?

c=176,000 miles /sec. Â*The mile is a unit of length. Â*The velocity of
the train is also measured in units of length divided by time. Â*In
addition to that, the train has a length that is measured in units of
length.
Robert B. Winn

And what are you trying to say with that?.
We are talking about the relativity of simultaneity, and that refers
to time relations, not to length contraction.
The whole point of this train thought experiment is to prove that time
is not absolute.

Miguel Rios- Hide quoted text -

- Show quoted text -

Relativity of simultaneity, as explained by Einstein, is dependent on
length contraction.

Actually, no it's not. You'll notice that the relativity of
simultaneity is established without needing to reference the distance
between the marks. However, you brought up the *additional*
information about the distance between the marks. In so doing, you
find out that there is a *consequence* of relativity of simultaneity:
relativity of length.

Â*If lightning strikes both ends of a train,
leaving marks on the ends of the train and marks on the track, the
only way the marks can be closer together than the length of the
train, as is required if the lightning at the front strikes first, is
if there is a distance contraction, as seen from the frame of
reference of the track.
Robert B. Winn