Re: Who is who?

On 20 jun, 11:13, dlzc <dl...@xxxxxxx> wrote:
Dear rvallshg:

On Jun 20, 6:03 am, rvall...@xxxxxxxxx wrote:





On 19 jun, 19:48, "N:dlzcD:aol T:com \(dlzc\)" <dl...@xxxxxxx> wrote:
...
<rvall...@xxxxxxxxx> wrote in message

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On 18 jun, 20:28, "N:dlzcD:aol T:com \(dlzc\)" <dl...@xxxxxxx>
wrote:
Dear rvallshg:

<rvall...@xxxxxxxxx> wrote in message

news:83049ebb-a632-4529-8089-9601f9b22804@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
...
Taking into account that in Euclidean
geometry the distance from A to B is
the same distance from B to A,

... problem with Euclidean ...

(First of all, very happy for your decision
to continue our talking. I remember you in
this group always as a very polite person).

First, I appreciate that you have insisted I *be* polite.  That
helps.  We had been visited by those that will not consider reasoned
argument, and are in general abusive.  It seems to be infective.

Total agreement.
… problem with 1905 Einsteinean… Re-read
my post where I begin showing 1905
Einstein’s literal words {…by the employment
of rigid standards of measurement and the
method of Euclidean geometry and can be
expressed in Cartesian co-ordinates}

Your "short cut" inherently blocks considerations of other "schools of
thought".  Such assertions prevent discussion, except of one's
starting point.  Better to let it naturally fall out in the
derivation, as Maxwell's aether falls out.

Well, I consider that the topic in this thread was put in the 1905
Relativity context. I have my reasons to separate it with great care
from the following development of Relativity and the rest of Physics.
But this doesn’t imply any blocking at all of other “schools of
thought” . Indeed, my principal interest is precisely to determine in
what extend 1905 Relativity remains being valid in our days, what can
be considered in it obsolete (or wrong) and what not.
and that by definition light spends
the same time to travel in both
directions,

... a fact that cannot be in evidence
in *this* Universe, without
instantaneous signalling ...

In my opinion, this is precisely the cause
why Einstein {establish BY DEFINITION that
the “time” required by light to travel
from A to B equals the “time” it requires
to travel from B to A}.

I disagree, else he would not have had the c+v and c-v in his initial
derivation.  Maxwell (laws of physics, postulate 1) provides that it
is always c, as a *result*, not a postulate.

Refer to the original Jun30 1905 paper. Einstein’s definition for time
between events separated in space is in paragraph 1, the c±v
expressions appears in paragraphs 2 and 3. If you consider this a
contradiction, those are major words. I am afraid that you are
confusing the algebraic vector addition of velocities that belong to
the same frame (used freely many times by Einstein in those
paragraphs) with the relativistic composition of velocities that refer
to different frames, derived in paragraph 5. Check by yourself what I
am saying. Einstein takes for granted Maxwell laws, including of
course the vacuum light speed derivation. That result of Maxwell is
used then by Einstein to develop a new concept about what time is,
introducing his light postulate.
It is a very essential part of the new
model created by him.

I disagree that it is a part that originate with him, but with
Maxwell.

See my previous comment. That c is vacuum light speed is not the new
thing Einstein introduced. Before Einstein vacuum light speed was c
only in the privileged absolute space and time Newtonian frame. After
Einstein that privileged frame disappears, being vacuum light speed c
in ALL the frames {in which the equations of Newtonian mechanics hold
good}(using Einstein’s own words).




then c is the same in both directions,
nothing in common with your "average
speed over a two-way path of light in
vacuum".

You missed the "two-way" part, didn't
you?  You cannot measure OWLS in this
Universe, you can only look for anisotropy.
All "light speed" measurements are TWLS.

I don’t think I missed something here. I
refer explicitly to your “average speed over
a two-way path of light in vacuum”, and also
to the relevant literal words of Einstein
DEFINING time between events that occur in
different points of an EUCLIDEAN space.

But you disallow other models by your applied limitations.  There is
no need to apply this at this time.

Of course that we can’t be at the same time using different
approaches. If you think that the original one (1905 Relativity) must
be abandoned, you must specify the causes, what you consider wrong or
inadequate in it.
For me has no sense at all to demand a
measurement of something DEFINED and
incorporated in a postulate.

There are many here that disagree with you.  Better to allow it, and
let Nature be the arbiter.

You said before that only TWLS measurements are possible. Then, how
can we know about the Nature decision if it is a constant vacuum light
speed in any inertial frame? (Einstein second postulate). Anyway, it
is a common scientific practice to evaluate theories by experiment of
its predictions, not making direct experiment of its postulates, more
ever taking into account that in this case the last alternative seems
to be impossible.
I am not saying that you are wrong
or not in that, I am only saying
that this is not what Einstein says.

That is not what Einstein says, that is
what you inferred from what Einstein said.

You can be right. Make explicit where you
think I am doing a wrong inference and why.

Done.  You cannot force someone to change their mind.  Nature either
will, or She will "break their legs".

Yes, we cannot force 1905 Einstein mind to be as we would want today.
This is why I am so careful trying to use always as possible the
literal writings. By the way, what Einstein’s literal words you
consider wrong or obsolete? Or what wrong inference from my part you
consider that violate the 1905 epoch context?




I am open to consider any other different
inference. Tell me what you think Einstein
said.

About the (c+v) and (c-v) expressions
that you refer, I remember you that
in the same Einstein's paper
(paragraph 3, derivation of Lorentz
transform) we have about 8 expressions
of this type. The important point here
is to know that you can add
vectorially any velocities (even with
one or the two being light ones) if
both refer to the same frame, and not
confuse this with the relativistic
composition of velocities derived by
Einstein in paragraph 5 that refer
to velocities that belong to
different frames.

This is not at issue.  The v is either
source velocity (if you "believe" in
ballistic light), or detector velocity
(if you "believe" in aether).  And
Nature does not care either way, unless
you look at "conservation of momentum".

The first post of this thread refers to
1905 Einstein’s Relativity.

Here is what was said:
<QUOTE>
The speed of Light quantum is constant: c=1,
no matter how the source or the observer moves.
/ Michelson’s  experiment. 1881.  SRT. 1905. /
<END QUOTE>

Yes, vacuum light speed was considered in Einstein’s second postulate
independent of source movement and the same in all frames (I identify
here observer with frame). I interpret SRT 1905 as 1905 Relativity. In
1881 light speed was considered c only in the aether.
In that context any reference to
“ballistic light” or “aether” is
totally out of place.

No.  It clearly is not.  MMX showed one type of aether did not exist.
SR (essentially) defines a class of aethers, and non-aether, that
agrees with experiment.

SR defining a class of aethers? Surely this is not 1905 Relativity.
Repeating Einstein’s literal words in the Introduction: {The
introduction of a “luminiferous ether” will prove to be superfluous…}..
I don’t care here about any post-1905 opinions (including Einstein’s
ones).
In the introduction of his 30 Jun 1905
paper Einstein writes {The introduction
of a “luminiferous ether” will prove to
be superfluous…}. I remain considering
very important to distinguish the
algebraic vectorial adding of velocities
(that belong to the same frame) from the
relativistic composition of velocities
(that belong to different frames). In my
opinion this is a very common source of
confusion, perhaps the one of Socratus
not understanding that even two light
rays can have a relative velocity
different (or not) from c (measured in
some frame),

Only if the frame is accelerating.  Which is not SR.  Please don't
wander off again...

I don’t know what accelerating frame are you referring (all what I
wrote has nothing to be with any accelerated frame). Maybe are you
referring to the gravitational accelerated clock at the rotating
Earth’s equator mentioned by Einstein at the end of paragraph 4? By
the way, you can see in that example (the unique real one in all the
paper) that a Lorentz Transform is being applied between an inertial
frame (the same ECI of today GPS!) and an accelerated frame (rotating
Earth’s surface). We are in agreement about that this is not today SR,
but surely it is 1905 Relativity! I will suppose that you don’t
pretend now to change 1905 Einstein’s mind, but maybe you can think
that all of this is today already obsolete. Let me know.
and at the same time have each of them
the same velocity c measured in any
frame. By the way, momentum is
conserved in any interacting body set,

Not with MMX performed with light from a relatively moving source.
The light must arrive at either c+v or c-v, and "bounce" at c-v or c+v
respectively.  Best to let other's models fail on their merits.

Are you assigning to a light ray a c+v or c-v velocity? This is by
sure not today SR (neither 1905 Relativity). By the second postulate
light has always c velocity in any frame, before and after any
“bounce”, no matter how the source is moving. You must find first that
Relativity can’t explain MMX in order to introduce an alternative
theory.
measured in any frame {…in which the
equations of Newtonian mechanics hold
good}(referring again to 1905 Einstein
literal words).

... or at least to your interpretation of them.  Again, it is much
later than 1905 now, we can move on to things (and clarity) we have
here and now.

Yes, of course we are now in 2008. But until now you haven’t proved
anything wrong in 1905 Relativity (or any interpretation of me). Make
an effort, refer to something that you consider the more easy or
evident to prove wrong. Maybe the 1905 Einstein’s Principle of
Relativity? Or the Conservation of Energy Principle used by Einstein
in his Sep27 1905 paper? Or the Universal mass-energy equivalence
derived in it?
David A. Smith- Ocultar texto de la cita -

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RVHG (Rafael Valls Hidalgo-Gato)
.

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