On May 7, 11:25Â*am, rbwinn wrote:
On May 7, 8:06Â*am, PD wrote:



On May 7, 9:28Â*am, rbwinn wrote:

On May 7, 6:48�am, YBM wrote:

kenseto a �crit :

ROTFLOL....you are not responding because you don't have a valid
argument. I am not going to respond the rest of your post until you
admit that Einstein did stipulate that the lightning strikes occur
simultaneously and that:
1. the track observer sees them to be simultaneous because he is not
moving wrt the light fronts.
2. the train observer sees them to be not simultaneous because he is
moving wrt the light fronts.

In SR, "not moving with respect to a light front" makes no sense.

I have a question, YBM. Â*Whether you talk about photons or light
fronts, in the frame of reference of the train, the light is traveling
at a speed of c from the two points where light was emitted in the
frame of reference of the train. Â*Those two points remain exactly
where they were relative to the frame of reference of the train, and
the movement of the track relative to the train changes nothing. Â*How
do you get that the observer on the train is moving wrt the light
fronts in his frame of reference?

The light fronts are not the points where the light was emitted, any
more than ripples are the same as the spot in the pond where the
pebble was dropped. The points on the train where the light was
emitted are stationary relative to the train. The light fronts are
moving relative to the train.

Â* Â* The observer on the train is not moving in his frame of
reference. Â*The train is not moving in the frame of reference of the
train, and the observer is at the middle of the train the entire
time. Â*The two light fronts are moving with a speed of c toward the
observer. Â*

Yes, read your own previous sentence again. The light fronts are
moving relative to the observer on the train.

At a speed of c. Â*You seem to have actually pictured this in your
mind.





The track is moving toward the rear of the train. Â*What the
track does is irrelevant because the light travels with a speed of c
in the frame of reference of the train, regardless of the motion of
the source of light. Â*Since the track is moving toward the rear of the
train at a speed less than the speed of light, any photons emitted in
the frame of reference of the train after the first photons emitted
will still reach the observer at the middle of the train after the
first ones emitted.
Â* Â* Â*What you and Einstein and all other believers in relativity of
simultaneity are doing is clinging to some beliefs that pertain to
absolute time by making the frame of reference of the track a
preferred frame of reference as far as transmission of light is
concerned. Â*According to you, the train moves toward the source of
light at the front of the train, so that light reaches the observer
first. Â*Wrong. Â*The train is not moving in its own frame of
reference. Â*The track is moving toward the rear of the train. Â*That is
entirely irrelevant as far as when the light will reach the observer
at the middle of the train. Â*You scientists have faithfully copied
Einstein's mistake for more than 100 years. Â*Don't you think it might
be time to think about it?

There is no mistake and there is no preferred frame. Here is what
happens.
1. The strikes occur simultaneously in the track frame.
2. The same strikes occur non-simultaneously in the train frame.
3. Because (2), the light arrives at the train observer at different
times -- which is exactly what the train observer reports.
4. The track observer ALSO says that the light from the rear strike
will arrive at the train observer after the light from the front
strike, even though (1) -- which is exactly what the train observer
reports.

To choose (1) or (2) as being more "real" than the other would be to
choose a preferred frame. But relativity declines to do that, and it
simply notes that the simultaneity of the strikes (even after taking
into account transit times) is frame-dependent.

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.

Sure, it explains it.

Here's how:
The track observer goes back after the train has passed and notes that
the marks on the track are 400 m apart. Remember that, for the track
observer, the strikes hit simultaneously. Since the marks are also on
the train, the track observer correctly notes that the train is 400 m
long. (This is what a length measurement entails anyway: marking the
locations of the ends of an object at the same time.)

Now the train observer goes back after the strikes have hit and notes
that the marks on the train are 500 m apart. But it's also true that
this observer saw the front strike happen before the rear strike ---
the strikes are not simultaneous in this frame. So it doesn't bother
this observer at all that the track observer sees the marks 400 m
apart. That's exactly what you'd expect if you marked the location of
the front of a moving object before you marked the location of the
rear of the moving object -- and that's exactly what the train
observer is sure happened.

The length of the train is frame-dependent. Whether the marks at the
end of the train were made at the same time, is also frame-dependent.

Does this help you understand?

Â*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. Â*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