On May 3, 10:03*am, kenseto wrote:
On May 2, 1:45*pm, PD wrote:

On May 2, 9:35*am, kenseto wrote:

What's wrong with these pictures???

1. In the twin paradox scenario SR claims that the traveling clock is
running at slower rate than the stay-at-home clock.

SR makes no such claim. Where are you reading such crap?
What SR tells you is precisely what will be *measured* -- that is, how
much time each twin will say has elapsed between the time of their
departure and the time of their reunion. SR does NOT make a claim
about which clock is running faster or slower in between.

So you are now saying that the SR stay-at-home observer doesn't claim
that the traveling clock is running at a slower rate....right??

Read what I said.

Previously you admitted that every SR observer claims that all clocks
moving wrt him are running slow.

I said no such thing. In fact, the last time you said it, I corrected
you.
What I said is that an *inertial* observer will claim that all clocks
moving *inertially* with respect to him are running slow. This doesn't
apply to the traveling twin, which is precisely the pedagogical point
of the twin puzzle to begin with. This seems to elude you and has
eluded you for a dozen years or more.

Is this not a valid claim anymore?





This means that
the passage of a stay at home clock second corresponds to the passage
of less than a clock second on the traveling clock. However when the
traveling clock rejoins the stay-at-home clock, the traveling clock
second is compared with the stay-at-home clock second *directly to
reach the conclusion that the traveling clock is younger. It seems
that SR is making the contradictory claims that: (a) the passage of a
traveling clock second does not correspond to the passage of a stay-at-
home clock second. (b) the passage of a traveling clock second does
correspond to the passage of a stay-at-home clock second.

2. In the pole and the barn paradox scenario:
SR claims that a physically longer pole can fit into a physically
shorter barn for a brief instant. However SR also claims that nothing
is physically happening to the pole. The question is: If nothing is
physically happening to the pole how can a physically longer pole can
fit into a physically shorter barn?

And the reverse question to you is: Why would you think that something
physical MUST happen to an object for its length to be different?

Because you said that the physically longer pole can fit into a
physically shorter barn.

But it's not physically longer. The pole is physically shorter, which
is why it fits in the barn.

I have no problem with the SR explanation if you say that length
contraction is just a perspective geometric projection effect. But you
also insisted that the contraction of the pole is physically real.

Yes. This doesn't mean that something physical had to happen to the
pole to make it shorter.

That where the problem comes in.

No problem.


After all, I can record the kinetic energy of a rock from two
different reference frames and will have different answers for the
same rock, even though I never did anything physical to the rock to
add energy to it. The same thing is true for length.

Also, what about from the pole's
point of view? How can it fit into an already physically shorter barn
when the barn is under go further physical contraction?

The answer to this question has to do with what "being inside the
barn" means. What does it mean for the pole to be inside the barn for
an instant in the barn frame?

It means that the physical length of the pole is really shorter than
the physical length of the barn in the barn frame.

I think you can do better than that.
Here, let me give you a hint: The ends of the pole are both inside the
barn at the same moment. Right?






Again it seems that SR is making contradictory claims.

3. The SR concept of Relativity of Simultaneity: Einstein used the
train and lightning strikes example to derive his concept of RoS.

No, not to derive it. He used it as a teaching example to explain it,
but the RoS lives independently of this example.

He
said that the track observer sees the strikes to be simultaneous
because the speed of light is isotropic in the track frame and the
track observer is located at equal distance from the strikes when the
strikes occur simultaneously.

No, that is NOT what he said. What he said is that BECAUSE the track
observer sees the strikes to be simultaneous and because the speed of
light is isotropic in the track frame and because the track observer
is located at equal distances from the strikes, THEN the strikes are
simultaneous.

NO....the strikes are stipulated to be simultaneous before the track
observer can see them to be simultaneous.

Not so. Where are you reading such crap? Cite the reference.




You have it backwards. Where are you reading such crap?

No you are the one who has it backward. If the strikes were not
stipulated to be simultaneous no observer at equal distance from the
strikes can see them to be simultaneous.



Also the track observer is not moving
wrt the light fronts from the strikes.

Of course he is. If the train observer were not moving relative to the
light fronts, they'd never reach him.

Hey idiot I said that the track observer is not moving wrt the light
fronts. Do you have a reading comprehension problem?

Sorry, I mistyped. If the track observer were not moving relative to
the light fronts, they'd never reach him.




OTOH he also claimed that the train observer is moving wrt the light
fronts from the strikes....

No, he didn't. Where are you reading such crap?

Hey idiot.... are you saying that Einstein didn't say that the train
observer is rushing toward the light front from the front of the train
and receding from the light front from the rear of the train and thus
he will see that light front from the front before he sees the light
front from the rear?

Yes, he did say this, and this is what the *track* observer says about
the light and the train observer. This is *not* what the train
observer would say is happening, of course.

You are so stupid.



the light front from the front of the train
will reach the train observer before the light front from the rear of
the train. This is why the train observer will not see the light
fronts to be simultaneous.

No, that's how the track observer makes physical sense (that is,
consistency) from his CONCLUSION that the strikes are simultaneous and
the FACT that the train observer does not see the strikes
simultaneously.

Sigh the train observer must make his own conclusion whether the
strikes are simultaneous.

And he concludes they are not. The track observer concludes they are.

The track observer cannot make that decision
for him. However the track observer can predict what the train
observer will see as follows:
The light path length from both strikes in the train = gamma*L
The transit time in the train for both light fronts to reach the train
observer = gamma*L/c
Therefore the train observer will see the strikes to be simultaneous
at a later time of (gamma*L/c).

That is certainly not what the train observer sees. Moreover, that is
not what the track observer predicts the train observer will see in
Einstein's writings.




However Einstein failed to realize that his
explanation violates his postulate that the speed of light is also
isotropic in the train.....at the time the strikes occur
simultaneously

But they don't strike simultaneous in the train frame. They only
strike simultaneously in the track frame.

Assertion is not a valid argument. The strikes are stipulated to be
simultaneous to be with.

Cite the reference. Title, publisher, page number, quotation, please.


Ken Seto