Androcles wrote:

"PDraper" <pdraper@yahoo.com> wrote in message
news:BE11F5BB.1E70%pdraper@yahoo.com...

On 1/17/05 5:59 PM, in article
LrXGd.152333$48.140018@fe1.news.blueyonder.co.uk, "Androcles"
<dummy@dummy.net> wrote:

"PD" <pdraper@yahoo.com> wrote in message
news:1105988498.458913.16740@z14g2000cwz.googlegroups.com...

Androcles wrote:

"PDraper" <pdraper@yahoo.com> wrote in message
news:BE113CB9.18AE%pdraper@yahoo.com...

On 1/15/05 9:07 AM, in article
ks9Gd.140879$48.24527@fe1.news.blueyonder.co.uk, "Androcles"
<dummy@dummy.net> wrote:

"PD" <pdraper@yahoo.com> wrote in message
news:1105792829.977686.183780@c13g2000cwb.googlegroups.com...

Androcles wrote:

"Gregory L. Hansen" <glhansen@steel.ucs.indiana.edu> wrote

in

message

I see nothing wrong with Einstein's recipie: simultaneously
measure

the
positions of the front and the back.

Stop right there. You've just said "simultaneously".
Define simultaneous.
Androcles.

Precisely! Better yet: define simultaneous in a way that will

give

preference to one observer over another.

So now you think trading length and time invariance for speed

of

light invariance so that we can measure the length of a moving
rod on the fly is a good idea?

Well, it's largely irrelevant whether I think the trade is a

good

idea

or
not. The issue is whether it's right. Einstein was indeed faced

with a

terrible decision. Preserve absoluteness of simultaneity and

abandon

the
constancy of the speed of light in all inertial frames; or
preserve

the
constancy of the speed of light in all inertial frames and

abandon

absoluteness of inertial frames. Then, once simultaneity is

abandoned,

you
find that between inertial frames, space and time become
intermixed

--

which
then forces again a terrible decision. Preserve the

independence

of

space
and time and abandon any scheme that allows them to be
commensurate

(which
in turn would force abandoning the constancy of the speed of

light

in

all
inertial frames); or preserve the scheme that allows them to be
commensurate
and abandon the independence of space and time. Einstein chose

the

latter in
both cases in order to preserve the PoR and the constancy of

speed

in

all
inertial frames, and then he went on to work out the

experimental

implications of what this would mean, and then put it to

experimental

test.
It turned out to be right, despite the terrible decisions to be

made.

1) The PoR doesn't need Einstein's help to preserve it.
2) Einstein does NOT preserve the PoR, he destroys it.

As you defined it below, yes. As correctly defined, no.

Einstein gave no definition. I have.
He said "Examples of this sort, together with the unsuccessful
attempts
to discover any motion of the earth relatively to the ``light
medium,''
suggest that the phenomena of electrodynamics as well as of

mechanics

possess no properties corresponding to the idea of absolute rest.
They
suggest rather that, as has already been shown to the first order

of

small quantities, the same laws of electrodynamics and optics will

be

valid for all frames of reference for which the equations of
mechanics
hold good. We will raise this conjecture (the purport of which

will

hereafter be called the ``Principle of Relativity'') to the status

of

a
postulate"

An example is NOT a definition, neither is a suggestion, and

neither

is
"been shown to the first order of small quantities."

Read it again.
Tell me if the following paraphrasing is incorrect.
=============
We will raise the following (hereafter called the "Principle of
Relativity")
to the status of a postulate:
That the same laws of electrodynamics and optics will be valid for

all

frames of reference for which the equations of mechanics hold good.
=============
By the way, the frames of reference for which the equations of
mechanics
hold good are inertial frames.

*****. You seem to imagine mechanical engineers do not understand

accelereration.

You said Einstein gave no definition of the Principle of Relativity.
He gave it above. Your claim is *****. You don't believe his
Principle of Relativity.
That does not change the fact that he defined it. You are wrong.
Admit it and remove your error.

Now you have to tell ME what my error is.

Mechanics includes acceleration
I'm sure you've heaard of F = dp/dt
That's an equation of mechanics.
It holds good for optics, too.

Yup, and it holds in all inertial frames.
The equations of electrodynamics and optics also hold in all inertial
frames, but they do not hold under vector addition of velocities. Your
PoR is *****.
Admit it and remove your error.

If you fail to do that, then you MUST acknowledge that your

statement

that
the PoR is the vector addition of velocities, is an error and

remove

the
erroneous statement from further discussion.

It is not an error, Einstein doesn't own it, and you don't understand

it.
The EXAMPLE he gives is that of the reciprocal action of a magnet

and a

coil
Moving the magnet past the coil has the same effect as moving the

coil

past the magnet. The law here is that an electric field is induced

in

the coil.

This part is right.

Let the coil move at u and the magnet move at v. The induced field

will

be proportional to u-v.

This part is wrong, or rather, only approximate, and Einstein makes no
claim that it is true, nor have you proved it. Prove it.

E = - dB/dt.

I repeat. The PoR is the vector addition of velocities.


I now invoke the rule :

"When we get to a point of conflict, we'll identify what the
error is on either side, and the party in error MUST acknowledge

the

error and remove the erroneous statement from further
discussion." --Paul Draper.
Show my error or admit your own.
I am not confused.

YOU are confused.
You may now state:

"Oh... Really?...Oh. I see I was
confused. OK, I get it now. Now what about...?"

3) Einstein does NOT preserve the independence of space and

time,

but

abandons them and combines then into "spacetime".

That's what I said.

No you didn't. You said:
"Then, once simultaneity is abandoned," and then showed that it was

not

to be abandoned with the collaborators agreeing on both ends of the
moving rod being simultaneously in the correct position for

measurement

of its length.
You are bullshitting.

No, I'm not and you're not listening. Simultaneity is a fine invariant
for multiple observers at rest in the same reference frame.
Simultaneity is not at all invariant for multiple observers in
different reference frames. Nowhere in Einstein's paper does he say
that simultaneity is defined for only one observer at one location in
one frame. If you think otherwise, prove it.

The PoR is the vector addition of velocities.

That is patently incorrect. The PoR (as applicable to SR) says

the

laws
of physics are invariant in all inertial frames.

Reference please!!!!
You are bullshitting.

See Einstein above, quoted by you above and paraphrased by me.
Please apologize for the accusation. I don't ***** in this

forum.

Yes you do.
You *are* a bullshitter. An example is not a definition.

Read my paraphrasing and tell me why it does not represent what
Einstein said.
Show me my error or abandon your cause.

The fact that the

Galilean transform leaves most (not all) laws of physics

invariant

does
not mean that the Galilean transform is the PoR. Nor does it say
that
the vector addition of velocities is the PoR.

Let A be a vehicle moving with velocity v along a highway with

respect

to the pavement.
Let B be a vehicle moving with velocity u along a highway with

respect

to the same pavement.
The relative velocity of B with respect to A is given by u-v,and

the
relative velocity of A with respect to B is given by v-u.

No, that isn't even right. Moreover, it is not a physical law or a law
of mechanics. Show me what physical law demands that the relative
velocity is given by v-u or u-v. Perhaps you can derive it from a real
physical law, like momentum conservation?

THAT is the PoR.
In the special case where v =u, A is not moving with respect to

B

and

B

is not moving with respect to A.
Einstein does NOT preserve the vector addition of velocities, he

claims

V = (v-u)/(1+ v(-u) /c^2 ) =/= v-u


We have on Einstein's own authority (and the real PoR )

"But the ray moves relatively to the initial point of k, when

measured

in the stationary system, with the velocity c-v, so that

x'/(c-v) =

t."

So the tip of the ray, relative to K moves at

V = ( u - (c-v) ) / (1 + u * (c-v) /c^2)

= ( u+v -c ) / (1+ (uc -vc)/c^2)
= ( u+v -c ) / (1+ c(u-v)/c^2)
= ( u+v -c ) / (1+ (u-v)/c)
= ( u+v -c ) / ([c+ (u-v)]/c)

= c( u+v -c ) / (c+ (u-v)) =/= c

and is therefore not c in the stationary system, contradicting

the

given.


Now get down off your pulpit and start producing a mathematical
proof

instead so speeches and rhetoric, because as you say, what you
think

is

largely irrelevant!
(Actually, totally irrelevant.)

So, then, if you would kindly proceed to the marked sections at

the

end
of the post we've been playing with, where some of the algebra

is,

we'll proceed.

Otherwise we'll be constantly yelling at each other in a

pantomime

of
"It turned out to be right" ,
"It turned out to be wrong",
"It turned out to be right" ,
"It turned out to be WRONG!

The way I look at it, some of the toughest "realignments" of

thinking

also
come with the blessing of simplicity gained.

It is irrelevant what you think, or the way you "look at it".
The facts are that Einstein published a paper which YOU are HERE

and

now

supposed to be validating.

Waxing poetic retracted.

Thank you. Don't try it again, please.

This from the fella that said the following:
====================================
Time for rhetoric, I think.
Ladies and Gentlemen of the Lurkers, I ask that you return a

verdict

of
Einstein guilty of fraud, as charged. The evidence is before you.

Do

not
be swayed by sympathy for the accused or other emotional
consideration,
do your duty and judge according to the evidence. The future of
science
is with you and your children.


Sorry its not a very good speech, I thought I had more time to
prepare
one, I hadn't expected this trial to be over so soon or so easy.

Over to you. Make your closing argument.
=====================================

Well of course. It's all over now. You've shown that Einstein's
definition of simultaneity is nonsense with collaborators spread
anywhere in the universe.

You are not listening, and I'll repeat it here. Simultaneity is a fine
invariant for multiple observers at rest in the same reference frame.
Simultaneity is not at all invariant for multiple observers in
different reference frames. Nowhere in Einstein's paper does he say
that simultaneity is defined for only one observer at one location in
one frame. If you think otherwise, prove it.

Time is the same everywhere, as Newton said. You haven't even come

close

to showing that it is different in a frame moving with respect to the

rest of the universe, and your admission that it is so throughout the

entire stationary frame precludes you from ever doing so.

Huh? How does it being the same throughout a whole inertial frame make
it identical to that in a different inertial frame?

WHAT DO YOU THINK THE POINT OF SYNCHRONIZING THE CLOCKS EVERYWHERE IN
A
GIVEN INERTIAL FRAME IS?

Go ahead and try if you want to. I'm ready to slice you up with your

own

words.

The facts are that Einstein published a paper which YOU are here

and

now
supposed to be proving to be patently incorrect, self-inconsistent

and

a
hoax. I don't need you waxing rhetorical.

Don't try it again, please.

As is so elegantly described in
the prologue to Taylor and Wheeler's book,

We are not concerned with Taylor and Wheeler's elegant rhetoric.

Neither

of them can hold a candle to Shakespeare, Milton, Tennyson,
Schiller,

Mark Twain or any of a host of other great bards. We are not in
judgment of literature here.
I object to you making speeches to the lurkers or giving

opinions

or
voicing the opinions of Taylor and Wheeler, which is hearsay.

Hearsay retracted.

Thank you. Don't try it again, please. I don't take kindly to
*****.

Neither do I. You said about the POR defined by Einstein.

Einstein gave no definition. I have.

Smells like cow-patty to me.
Don't try it again, please.

Make your argument. I've given a definition of the PoR as the vector
addtion
of velocities, not some vague notion that the laws of physics are

the

same in all inertial frames.

I don't need to make an argument. I am quoting Einstein, who defined
the PoR as being that "vague notion" and elevated it to a POSTULATE.
That means "assumed to be true". He does not come to you and say, "So,
Androcles, do you suppose this is really true?" He is ASSUMING it is
true, taking it to be a postulate. You don't like it. You think the
PoR
should mean something else. However, that is NOT what Einstein is
assuming. You said Einstein did not define it. You are wrong, and you
need to concede your error. You said Einstein assumed the PoR and then
trashed it. Perhaps what you meant is that he did NOT assume YOUR
definition of the PoR and then he trashed YOUR definition of the PoR.
NOWHERE in his paper does he say that the vector addition of
velocities
is assumed to be a postulate. You are wrong, and you need to concede
your error.

I can wrap the wire coil tightly around the magnet, accelerate both

by

throwing then across the rooom, and it *STILL won't produces a

current

in the wire. Inertial frames my arse. The velocity of the coil will

be

u, the velocity of the magnet will be v, and no field when v = u.
Only a relative velocity between coil and magnet will produce an
effect.

This is true, but that relative velocity is not u-v or v-u, and you
have not demonstrated one physical law that says it is.

The PoR IS the vector addition of velocities
If one car follows another at the same velocity down the highway, the

laws of mechanics says they will not collide and holds good.
If the following car has a greater velocity than the leading car, the

laws of mechanics says there will be a colision and holds good.

This is true, but that relative velocity is not u-v or v-u, and you
have not demonstrated one physical law that says it is.

For optics, the same law applies. The trailing light beam will pass

the

leading light beam and arrive first.

What law? u-v or v-u is not a law.

Speed of light invariant is ***** and denies the PoR.
So are your fucking rules, you are a hypocrite.
Androcles.

[snip, to point out that you continue to abrogate the agreement. These
"fucking rules" are fucking rules you agreed to.]

ANSWER THE BELOW OR OUR CONVERSATION IS OVER.

You have not addressed the next steps in the algebra. For the

fourth

and
final time, address them, or you will have abrogated our agreement

by

being
nonresponsive.

Androcles:
Agreed. All synchronization to be done at rest. Let us now
declare
the clocks and the rod to be synchronized, and you may begin
your experiment.

OK, so now what we're going to do is we're going to take a rod
that
was
stationary in frame K, and we'll walk it backwards a few miles,

and
we're
going to speed it up to speed v toward the right in frame K.

It's

reached v
by the time it passes the origin of K. (It actually doesn't

matter

that
it
was ever stationary in the frame K, but Einstein says we'll do

it

that
way,
so we'll go along). After the rod has been sped up, this rod is
stationary
in the frame k. That is, the location of the emitter and

receiver

at
one end
of the rod are at a fixed location in k, and the location of

the

mirror
at
the other end of the rod is at another fixed location in k.

Now, the observer in K knows that this rod can't be used to to
synchronize
any yardsticks in K, because it's not at rest. Moreover, the
emitter/mirror/receiver can't be used to synchronize the clocks

in

K,
because the system is not at rest. That doesn't really matter.

The

K
observer can recheck the synchronization of K's yardsticks and
clocks
with
another rod and emitter/mirror/receiver stationary in K. As you

say,
we'll
assume there is no drift, so the resynching would just verify

that

clocks
are still synched and yardsticks are still the same length.

However, we *can* measure a length of the moving rod in K. The
prescription
above will do it.

Moreover, the moving rod *can* be used as a synching system in

k.

Agree so far?

OK, now there are three events:
The "0" event, where a flash of light is emitted from one end,

the

"left end", of the rod that is moving in K and stationary in k.
The "1" event, where the light bounces off the mirror at the

other

end, the "right end", of the same rod.
The "2" event, where the light returns to the receiver at the

left

end
of the same rod.

The observer in k labels the coordinates of these events as
(xi0,eta0,zeta0,tau0),
(xi1,eta1,zeta1,tau1),
(xi2,eta2,zeta2,tau2).

Now because the rod is stationary in k, we know that xi0 = xi2.
We have also set it up so that

eta0=eta1=eta2=zeta0=zeta1=zeta2=0.

We know that the length of the rod as measured in k is (xi1 -

xi0),

because the rod is stationary in k and the rod has a fixed

length

in
k.
That is, the right-end of the rod is always at xi1 in this

frame,

which
means that the right end of the rod is at xi1 at tau0 as well as

at

tau1. We've satisfied the procedure for measuring the length of

a

stationary object.

Finally, because the rod is stationary in k, we can use it as a
clock
synchronization rod in k. Since we previously synched the clocks

in

k,
and since the clocks are ideal (don't drift), then this synch

check

will simply confirm the synchronization condition in this frame.
Namely:
tau1 = (1/2)(tau0 + tau2).

Before we move on to how the observer in K sees these events,

are

we
in
agreement that this is a good picture of what Einstein intends

in

his
set-up so far?

Androcles wrote:

Speed of light invariant is ***** and denies the PoR.
So are your fucking rules, you are a hypocrite.
Androcles.

[snip, to point out that you continue to abrogate the agreement. These
"fucking rules" are fucking rules you agreed to.]

ANSWER THE BELOW OR OUR CONVERSATION IS OVER.

On 1/15/05 9:07 AM, in article
ks9Gd.140879$48.24527@fe1.news.blueyonder.co.uk, "Androcles"
<dummy@dummy.net> wrote:

"PD" <pdraper@yahoo.com> wrote in message
news:1105792829.977686.183780@c13g2000cwb.googlegroups.com...

Androcles wrote:

"Gregory L. Hansen" <glhansen@steel.ucs.indiana.edu> wrote in message

I see nothing wrong with Einstein's recipie: simultaneously
measure the positions of the front and the back.

Stop right there. You've just said "simultaneously".
Define simultaneous.
Androcles.

Precisely! Better yet: define simultaneous in a way that will give
preference to one observer over another.

So now you think trading length and time invariance for speed of
light invariance so that we can measure the length of a moving
rod on the fly is a good idea?

Well, it's largely irrelevant whether I think the trade is a good idea or
not. The issue is whether it's right. Einstein was indeed faced with a
terrible decision. Preserve absoluteness of simultaneity and abandon the
constancy of the speed of light in all inertial frames; or preserve the
constancy of the speed of light in all inertial frames and abandon
absoluteness of inertial frames. Then, once simultaneity is abandoned, you
find that between inertial frames, space and time become intermixed -- which
then forces again a terrible decision. Preserve the independence of space
and time and abandon any scheme that allows them to be commensurate (which
in turn would force abandoning the constancy of the speed of light in all
inertial frames); or preserve the scheme that allows them to be commensurate
and abandon the independence of space and time. Einstein chose the latter in
both cases in order to preserve the PoR and the constancy of speed in all
inertial frames, and then he went on to work out the experimental
implications of what this would mean, and then put it to experimental test.
It turned out to be right, despite the terrible decisions to be made.

"Gregory L. Hansen" <glhansen@steel.ucs.indiana.edu> wrote in message
news:cs9uc5$fcl$2@rainier.uits.indiana.edu...

In article <NA_Fd.135846$48.119998@fe1.news.blueyonder.co.uk>,
Androcles <dummy@dummy.net> wrote:

"Gregory L. Hansen" <glhansen@steel.ucs.indiana.edu> wrote in message
news:cs9rcd$dvn$4@rainier.uits.indiana.edu...

In article <p3WFd.96280$C8.24495@fe3.news.blueyonder.co.uk>,
Androcles <dummy@dummy.net> wrote:

"Gregory L. Hansen" <glhansen@steel.ucs.indiana.edu> wrote in
message
news:cs99n4$79r$1@rainier.uits.indiana.edu...

In article <B0VFd.95629$C8.85428@fe3.news.blueyonder.co.uk>,
Androcles <dummy@dummy.net> wrote:

"PD" <pdraper@yahoo.com> wrote in message
news:1105729764.441171.196420@c13g2000cwb.googlegroups.com...

This is all covered in the section in Einstein's paper in the
section
on the relativity of simultaneity.

Does the K-observer conclude the k-rod is shorter than the K-rod,
or not? Yes/No.
There can be no ambiguity to the question.
"Neither" is not an acceptable answer.
I didn't ask you
"Does the k-observer conclude the K-rod is shorter than the
k-rod?"
because I'm not interested in the answer at this time.
Now, please answer my question unanbiguously with a yes or a no.

If I may butt in, I think Draper's point was that when K watches k
measure
the length, he won't agree that it was a measurement of the
length!
And
vice versa. So when k gives K a measured length, K will say "Your
number
is smaller than mine, but I don't know what the hell it is. I
watched
you
do it, and that's not how to measure a length."

That's fine, but k is carrying out an illegitimate procedure. I had
previously
agreed with Paul that the measurement can only be carried out when
the rod to be measured and the measuring rod were relatively at
rest.
Observer K will not agree with observer k's guesstimate,
as you point out, but observer k himself will be uncertain.
Androcles.

That seems like an unnecessary restriction. You didn't really agree
with
Paul that the concept of length has no meaning for a moving object,
did
you? Did I misread?

k measures the length of the rod with a ruler that is stationary
with
respect to k. It doesn't have to be stationary with respect to the
rod,
but it has to be stationary with respect to k or else it's not a
measurement of length in k's frame.

How do you measure the wheelbase of a moving bus or truck
holding a rod wich is stationary with respect to you at the side
of a highway?

How do you measure one strip of the dotted white line down
the middle of the road holding a rod while travelling in a car
at 70 mph with a calibrated rod in your hand?

I see nothing wrong with Einstein's recipie: simultaneously measure
the
positions of the front and the back.

Stop right there. You've just said "simultaneously".
Define simultaneous.
Androcles.